797 VA Computrace Software Version 1.3.x Manual 8.797.
Metrohm AG CH-9101 Herisau Switzerland Phone +41 71 353 85 85 Fax +41 71 353 89 01 info@metrohm.com www.metrohm.com 797 VA Computrace Software Version 1.3.x Manual 8.797.8002EN 08.
Teachware Metrohm AG CH-9101 Herisau teachware@metrohm.com This documentation is protected by copyright. All rights reserved. Although all the information given in this documentation has been checked with great care, errors cannot be entirely excluded. Should you notice any mistakes please send us your comments using the address given above. Documentation in additional languages can be found on http://products.metrohm.com under Literature/Technical documentation.
Table of contents Table of contents 1 Introduction ......................................................... 1 1.1 Purpose of program................................................................ 1 1.2 General information................................................................ 2 Hardware requirements for the PC................................................. 2 Demo version................................................................................. 2 Registration ...........................
Table of contents Film deposition selection.............................................................. 16 Cleaning procedure selection ....................................................... 16 2.6 User menu ............................................................................. 16 Login ........................................................................................... 16 User rights ...................................................................................
Table of contents Axis properties............................................................................. 65 Curve properties .......................................................................... 67 Line properties............................................................................. 68 4 Exploratory mode .............................................. 70 4.1 Exploratory mode overview.................................................. 70 Exploratory mode features...........................
Table of contents Export........................................................................................ 105 Dosing Devices .......................................................................... 107 5.3 Monitor ............................................................................... 108 Start determination.................................................................... 108 Stop/Hold determination ........................................................... 109 Monitor determination ..
Table of contents Data acquisition......................................................................... 138 Background compensation ........................................................ 139 Smoothing and differentiation ................................................... 139 Peak recognition........................................................................ 139 Baseline calculation.................................................................... 140 Evaluation quantity calculation ..........
Table of contents Computrace control window ..................................................... 197 7.2 Dosing Device control ......................................................... 199 Dosing Device control selection ................................................. 199 Dosino control window ............................................................. 199 7.3 Pump control ...................................................................... 200 Pump control selection ................................
Table of contents Print determination results and curves ....................................... 218 8.6 Analyze Electroplating Bath Solutions................................ 218 Introduction............................................................................... 218 Choose the mode in Electroplating Bath VA............................... 219 Choose the Calibration technique in Electroplating Bath VA ...... 219 Operate a sequence in Electroplating Bath VA ...........................
Table of contents Electrolytes ................................................................................ 259 Standard solutions ..................................................................... 259 Samples ..................................................................................... 260 Blank values, contamination ...................................................... 260 Selection of VA Measurement mode.......................................... 260 9.6 Voltammetric problems.............
1.1 Purpose of program 1 Introduction 1.1 Purpose of program «797 VA Computrace Software 1.3.x» is the name of the control software for the PC-controlled 797 VA Computrace System for voltammetric analysis. This system consists of the following parts: 1.797.0010 VA Computrace Stand with accessories 6.2151.020 USB Cable 6.6053.030 797 VA Computrace Software 1.3.x For a detailed description of the hardware components of the 797 VA Computrace System, see the 797 Hardware Manual.
1 Introduction 1.2 General information Hardware requirements for the PC Computer Pentium III with 1 GHz or higher Operating system Windows™ 2000, Windows™ XP Professional, Windows™ Vista Professional Free space on hard disk 40 MB for program files Working memory RAM 256 MB Graphics resolution 1024×768 or more Interface 1 free USB connection Printer Any printer supported by operating system Note: Set the screen saver to "None" and deactivate any energy saving features.
1.3 Installation Data Folder for storage of new signal (*.sig) and determination files (*.dth). In Windows Vista, this folder is stored in ProgramData/Metrohm/797 VA Computrace. Demo data Folder containing signal and determination file examples. The subfolder CVS contains examples for the electroplating bath analysis, the subfolder Practical Voltammetry all examples of the 8.757.5003 Metrohm Monograph "Practical Voltammetry", which is available from Metrohm on request.
1 Introduction 2. If required, connect the 846 Dosing Interface to one of the USB ports of the 797 VA Computrace or the PC. Connect the 846 Dosing Interface to the mains supply. 3. Connect the Dosing Device via MSB connection to the 797 VA Computrace stand or the 846 Dosing Interface. 4. Switch on the 797 VA Computrace stand. 5. Open 797 VA Computrace Software 1.3.x and log in. 6.
1.3 Installation 9. Start the 797 VA Computrace Software 1.3.x. 10. Set hardware settings for the 863 Compact VA Autosampler. 11. Check the checkbox for Relay box / Pump Station on the Automation tab of the GENERAL SETTINGS window, and define the default settings for the pumps. 12. Set hardware settings for Dosing Devices. 13. Define the addition or predose solution in the DOSINOS window.
1 Introduction 12. Make hardware settings for Dosing Devices. 13. Define the addition or predose solution in the DOSINOS window. Deinstallation 1. Select / Settings / Control panel. 2. Double-click the Software icon. 3. Select 797 VA Computrace in the list and click on . Select the Remove option and click on . All program files and icons should be removed. 1.4 Overview of program windows 797 VA Computrace consists of different windows whose functionality is linked together.
1.5 Overview of file types 1.5 PUMP CONTROL Manual control of siphoning and rinsing pump FILM DEPOSITION Program for Hg film deposition on solid state electrodes CLEANING PROCEDURE Program for cleaning procedures for solid state electrodes Overview of file types The following file types are produced by the 797 VA Computrace Software 1.3.x: 797 VA Computrace – Software *.csv Text file in .csv-format (ASCII file) for data export Results can be stored as .csv-file.
1 Introduction sults block. In the case of determination point export, this data file contains a block of the used method parameters followed by the sweep blocks of X and Y values each preceded by VR number and number of measurement points.
2.1 Main window overview 2 Main window 2.1 Main window overview Main window elements The MAIN WINDOW is the center of the 797 VA Computrace Software 1.3.x. Its elements are the menu bar, the tool bar and the status bar indicating user, method and determination.
2 Main window Main window icons It depends on the selected mode (exploratory or determination) whether the following icons are displayed in the MAIN WINDOW or not. Exit the VA Computrace program. Print reports and curves. Switch to exploratory mode. Switch to determination mode. Load default parameters for exploratory or determination mode. Load existing method or signal file. Save method or signal file. Load existing determination file. Save determination file. Manual control of 797 VA Computrace stand.
2.2 Starting/closing the program Continue measurement. Go to next step in operation sequence. Help. 2.2 Starting/closing the program Starting the VA Computrace program Start the Program Double-click the 797 VA Computrace icon or the Ct797.exe file to start the 797 VA Computrace program. The 797 VA COMPUTRACE LOGIN window appears. Enter Name and Password and select the desired option Start measurements for starting measurements or Recalculate only for recalculation.
2 Main window 2.3 File menu Method files Method files (*.mth) contain all the specifications and parameters for running a determination. They can only be loaded or saved in the determination mode. MAIN WINDOW / File / New method (Ctrl+N) Load a standard template with the selected mode for creating a new method. MAIN WINDOW / File / Load method (Ctrl+O) Load an existing method file. Normally, method files are stored in the Method folder.
2.3 File menu memory into a data file (extension *.txt). This data file contains a block of the used method parameters followed by the sweep blocks of X and Y values each preceded by VR number and number of measurement points. The data files can be imported into spreadsheet programs like Microsoft Excel. MAIN WINDOW / FILE / EXPORT EXTENDED DETERMINATION POINTS...
2 Main window Export previously saved determination data to the database. Procedure after starting Export To Database / Determination Files.. The Select Determination Files window opens, choose the determination(s) you want to export and click . If Ask for database file.. is activated for Manual Transfer Mode on the Database tab in the GENERAL SETTINGS window, the SELECT DETERMINATION DATABASE FILE window opens, and you choose the database file where the selected determination(s) is(are) stored.
2.4 Mode menu MAIN WINDOW / File / Save signal as ... Save the current signal loaded in the working memory in a new file. Enter name and directory for storage of the signal file. MAIN WINDOW / File / Export signal points Save the measurement points of the sweep of the current signal loaded in the working memory into a data file (extension *.txt). This data file contains a block of the used method parameters followed by the sweep block of X and Y values preceded by the number of measurement points.
2 Main window ding and displaying of determinations (see section 5). 2.5 Utility menu Computrace control selection MAIN WINDOW / Utility / Computrace control Start manual control of 797 VA Computrace stand (details see section 7.1). Dosing Device control selection MAIN WINDOW / Utility / Dosino control Control of Dosing Devices (Possible: 700/800 Dosinos; 685/805 Dosimats) connected to the 797 VA Computrace stand or to the 846 Dosing Interface (details see section 7.2).
2.6 User menu Enter the desired Name and Password to login as a new user and click OK. Note: In case that the firmware of your 797 VA Computrace stand is version 3.01 or older, the firmware update dialog starts automatically after login. To update the firmware, confirm each step with or . The information about the version of the firmware can be gathered from the window Info (this window can be opened via MAIN WINDOW / Help / About 797 VA Computrace ... ).
2 Main window User List of all users. The user rights are displayed for the selected and highlighted user. The following users with blank passwords are defined as default examples: Administrator Access to all program parts and allowance to change the user rights. Analist Read only access to working method, curves/results and general settings. Creator Only access to Working method and Exploratory mode.
2.6 User menu User rights The different user rights options can be changed for the selected user: none No access to this program part. R Permission to read in this program part. R/W Permission to read/write in this program part. Change allowance Permission to edit the user rights. Add a new user to the users list. The ADD NEW USER window appears. Name [ max. 13 characters; ] User name. This name is inserted in the User field of all reports and results windows. Password [ max.
2 Main window Use default locations Set default directories for Data folder and Method folder. Data folder User specific folder for determination and signal files. Use to change the folder. Method folder User specific folder for method files. Use to change the folder. User rights overview MAIN WINDOW / User / Overview The OVERVIEW window displaying the list of all users appears. Detailed user list with all user rights. User list without user rights. User list with small icons.
2.7 Settings menu Auto save options Auto save determination and signal If this option is enabled, every signal or determination file is stored automatically in the data folder (defined in the User Directories tab of the USER RIGHTS window) after the end of the measurement. Save calibration curves additionally without date and time If this option is enabled, every determination will be saved twice, once with date/time and the defined Sample ID (e.g. "07181430_CalibrationLead.
2 Main window Basic settings for the csv export. Record delimiter Selection of the characters which will separate the determinations resp.
2.7 Settings menu Dosing settings MAIN WINDOW / Settings / General Settings On the Dosinos tab of the GENERAL SETTINGS windows, the default settings for Dosing Devices which are connected to the 797 VA Computrace can be defined. On the Dosing Interface tab of the GENERAL SETTINGS windows, the default settings for Dosing Devices which are connected to the 846 Dosing Interface can be defined. This tab is only displayed if a 846 Dosing Interface is connected.
2 Main window Dosino Device MSB 4 846 Dosing Interface MSB1 5 846 Dosing Interface MSB2 6 846 Dosing Interface MSB3 7 846 Dosing Interface MSB4 Volume Burette (mL) [read only] Volume of the exchange unit of the Dosing Device. Type [read only] Which Dosing Device is connected (possible: 700/800 Dosino, 685/805 Dosimat). Dose rate (mL/min) [ 0.01 ... 166 mL/min (depending on dosing/exchange unit); 2 mL/min ] Dosing rate of the Dosing Device. The dose rate is limited by the 3.
2.7 Settings menu waste container). Using Port 3 you can reduce contamination of the measuring cell and the electrode. Moreover the emptying can be conducted faster. Note: If you choose Port 3 for menu item Prep/Empty via port, you must install an FEP Tubing Connection 6.1805.530 from Port 3 to a waste container. No. of Prep cycles [ 0, 1, ... ,5 ; 0 ] Define the number of "Prep-Cycles" for the respective Dosino.
2 Main window With 843: With 838: 26 797 VA Computrace – Software
2.7 Settings menu Sample handling Define the default settings of a connected used automation unit. Sample processor [ read only ] Select the connected sample processor. Time to change sample [ > 25 s ; 30 s ] (only with the 863 Compact VA Autosampler) During that time, the rack is changed to the next position and the needle is immersed into the sample solution. It is the time between first and second remote signal that are sent from 797 Computrace to the Autosampler (see 863 Manual).
2 Main window of the program at the 838 Advanced Sample Processor. Rinsing Define the default settings of a possibly used pump unit. Relay box / Pump Station Check the checkbox if a 843 Pump Station or a 731 Relay Box with 772 Pump Units or 823 Membrane Pump Units is connected. Automatic rinsing Check the checkbox to rinse automatically. Note: If Automatic rinsing is activated, the measuring cell is siphoned off at the beginning of every determination.
2.7 Settings menu Note: Before starting the test, switch on either 863 Compact VA Autosampler(set Method 2) or the 838 Advanced Sample Processor (set method VA, and enter the position of the first sample vessel for the 838 parameter "SAMPLE" with the 838 keypad), and place two sample vessels filled with water on the sample rack. For details on the use of the 863 Compact VA Autosampler, or the 838 Advanced Sample Processor see 863 Manual, 838 Manual.
2 Main window Define, how long before the expiring date a warning message is displayed. Action, if validation expires You can choose between just showing a warning Show warning only, or stopping the measurements Stop measurements. Note: GLP can only be started if there is no “blank user”. “Blank user” has to be removed to apply GLP. GLP Wizard Clicking the button on the GLP tab of the GENERAL SETTINGS window starts the GLP Wizard.
2.7 Settings menu Note: Occasional electrode tests should be done with in the COMPUTRACE CONTROL window and not with the GLP Wizard (not to overwrite GLP data). Validation of a chosen method Performs a validation of accuracy and precision using Standard Operating Procedures (SOP). Note: When the GLP Wizard is executed, the current GLP data that is stored in the software and in the 797 VA Computrace instrument is overwritten. GLP Diagnostics 1.
2 Main window 3. After testing, the results are shown In the Dummy Cell Test_L page of the GLP WIZARD window. 4. Press one more time; the Dummy Cell Test_D page of the GLP WIZARD window opens. 5. Proceed as described and press one more time; the MONITOR window opens. 6. After testing, the results are shown In the Dummy Cell Test_D page of the GLP WIZARD window. 7. Press one more time; the Summary of GLP validation page of the GLP WIZARD window opens. 8. Press .
2.7 Settings menu Note: The working method parameters cannot be changed during the GLP validation. Optimization of the method should be done before the GLP validation. 4. Press one more time; the PLACE SAMPLE window opens. Fill the measurement vessel as defined and press , the MONITOR window opens and the measurement starts. 5. The Result part of the Validation of Standard Method page of the GLP WIZARD window opens. 6.
2 Main window Save settings MAIN WINDOW / Settings / Save now This function saves the actual settings of the software: Open windows, window position and size, general settings. MAIN WINDOW / Settings / Save on exit If this function is enabled, the software settings are stored when the software is quit. 2.8 Window menu Tiling of windows MAIN WINDOW / Window / Tile All opened windows are tiled.
2.8 Window menu tion 4.2) (F11 only works, if the Main Window is selected). MAIN WINDOW / Window / Exploratory curves (F12) The EXPLORATORY CURVES window will be ope- ned or (if it is already open) closed (see section 4.3) (F12 only works, if the Main Window is selected). The opened windows are marked with a checkbox sign. Display settings for Main window MAIN WINDOW / Window / Status bar Switch on/off display of status bar in the MAIN WINDOW.
3 General settings for exploratory and determination mode 3 General settings for exploratory and determination mode 3.1 Electrodes MME MME stands for Multi-Mode Electrode and is the working electrode commonly used in the 797 VA Computrace stand.
3.1 Electrodes Hg drop surface t Voltage step time Notes: • In the exploratory mode, the DME can be used for the measurement modes DC, NP, DP and AC. In the determination mode, the DME can be used for the measurement modes DP and AC. • An advantage of the DME compared with the SMDE is that the MME capillary is subjected to less mechanical stress.
3 General settings for exploratory and determination mode Notes: • In the exploratory mode, the SMDE can be used for the measurement modes DC, NP, DP and AC. In the determination mode, the SMDE can be used for the measurement modes DP and AC. • An advantage of the SMDE compared with the DME is its greater sensitivity as the electrode surface and hence the baseline remains constant during the measurement. Further, less mercury is needed.
3.1 Electrodes RDE/SSE RDE stands for Rotating Disk Electrode and is used for direct and stripping determinations with Solid State Electrodes (SSE). Stirrer/RDE (rpm) [ 0...3000 rpm ; 2000 rpm ] Revolutions per minute of the rotating disk electrode. The stirring of the RDE remains active during all preparation procedure steps until the start of sweep. Surface t Notes: • The RDE can be used for all measurement modes.
3 General settings for exploratory and determination mode 3.2 VA measurement modes DP – Differential Pulse General: DP or Differential Pulse voltammetry is the most universal and frequently used voltammetric measurement mode. It is equally well suited for irreversible and reversible systems and offers a high sensitivity.
3.2 VA measurement modes Sweep parameters: Hydrodynamic (measurement) [ on, off ; off ] Enable/disable stirring of the RDE/SSE during the sweep. Start potential (V) [ -5...+5 V ; -0.9 V ] Start voltage for the voltage sweep. End potential (V) [ -5...+5 V ; -0.1 V ] Final voltage for the voltage sweep. Pulse amplitude (V) [ -1...+1 V ; 0.05 V ] Pulse amplitude of the voltage pulse superimposed on the direct voltage (pos. values = same direction; neg.
3 General settings for exploratory and determination mode SqW – Square Wave General: SqW or Square Wave voltammetry is primarily suitable for reversible electrode processes. It is used particularly for sensitive stripping voltammetric determinations at the HMDE or RDE. The SqW measurement mode can be set for the exploratory and determination mode by selecting SqW - Square wave for the Mode parameter in the EXPLORATORY SPECIFICATION or WORKING METHOD SPECIFICATIONS window.
3.2 VA measurement modes Sweep parameters: Hydrodynamic (measurement) [ on, off ; off ] Enable/disable stirring of the RDE/SSE during the sweep. Start potential (V) [ -5...+5 V ; -0.9 V ] Start voltage for the voltage sweep. End potential (V) [ -5...+5 V ; -0.1 V ] Final voltage for the voltage sweep. Voltage step (V) [ > 0 V ; 0.006 V ] Voltage step for direct voltage ramp. Amplitude (V) [ > 0...+1 V ; 0.02 V ] Voltage amplitude of the square wave voltage superimposed on the direct voltage.
3 General settings for exploratory and determination mode DC – Sampled Direct Current General: DC or Sampled Direct Current voltammetry is the classic, simplest voltammetric measurement mode with limited sensitivity. It is mainly used for the investigation of reversible redox systems. The DC measurement mode can be set for the exploratory and determination mode by selecting DC - Sampled direct current for the Mode parameter in the EXPLORATORY SPECIFICATION or WORKING METHOD SPECIFICATIONS window.
3.2 VA measurement modes Sweep parameters: Hydrodynamic (measurement) [ on, off ; off ] Enable/disable stirring of the RDE/SSE during the sweep. Start potential (V) [ -5...+5 V ; -0.9 V ] Start voltage for the voltage sweep. End potential (V) [ -5...+5 V ; -0.1 V ] Final voltage for the voltage sweep. Voltage step (V) [ > 0 V ; 0.006 V ] Voltage step for direct voltage ramp. Voltage step time (s) [ > 0 s ; 0.
3 General settings for exploratory and determination mode NP – Normal Pulse (for "Exploratory" only) General: NP or Normal Pulse voltammetry is the classic pulse voltammetric measurement mode with direct recording of the current. It is equally well suited for irreversible and reversible systems and offers a higher sensitivity than the DC voltammetry. The NP measurement mode can only be set for the exploratory mode by selecting NP Normal pulse for the Mode parameter in the EXPLORATORY SPECIFICATION window.
3.2 VA measurement modes Sweep parameters: Hydrodynamic (measurement) [ on, off ; off ] Enable/disable stirring of the RDE/SSE during the sweep. Start potential (V) [ -5...+5 V ; -0.9 V ] Start voltage for the voltage sweep. End potential (V) [ -5...+5 V ; -0.1 V ] Final voltage for the voltage sweep. Base potential (V) [ -5...+5 V ; -0.9 V ] Base voltage for voltage sweep. Pulse time (s) [ ≥ 500 μs ; 0.04 s ] Time interval during which an increasing voltage pulse is superimposed on the base voltage.
3 General settings for exploratory and determination mode CV – Cyclic Voltammetry General: CV or Cyclic voltammetry is mainly used to investigate the reversibility of electrode processes and for kinetic studies. The CV measurement mode can be set for the exploratory and determination mode by selecting CV - Cyclic voltammetry for the Mode parameter in the EXPLORATORY SPECIFICATION or WORKING METHOD SPECIFICATIONS window.
3.2 VA measurement modes Sweep parameters: Hydrodynamic (measurement) [ on, off ; off ] Enable/disable stirring of the RDE/SSE during the sweep. Start potential (V) [ -5...+5 V ; -0.9 V ] Start voltage for the voltage sweep. First vertex potential (V) [ -5...+5 V ; -0.1 V ] First turning point for the potential sweep. Second vertex potential (V) [ -5...+5 V ; -0.9 V ] Second turning point for the potential sweep (Can be different from the Start potential). Voltage step (V) [ > 0 V ; 0.
3 General settings for exploratory and determination mode PSA – Potentiometric Stripping Analysis General: PSA or Potentiometric stripping analysis with chemical oxidation is mainly used to determine substances in an organic matrix with the aid of mercury film electrodes without prior digestion.
3.2 VA measurement modes Sweep parameters: Hydrodynamic (measurement) [ on, off ; off ] Enable/disable stirring of the RDE/SSE during the sweep. Potential limit (V) [ -5...+5 V ; -0.2 V ] Voltage limit for PSA sweep. Maximum time (s) [ > 0 ; 20 s ] Time limit for PSA sweep. Notes: • The PSA measurement mode should only be used with RDE electrodes (mainly with Hg film).
3 General settings for exploratory and determination mode U Deposition potential Potential limit Deposition time Maximum time dt/dU t Peak area Peak voltage U Sweep parameters: Hydrodynamic (measurement) [ on, off ; off ] Enable/disable stirring of the RDE/SSE during the sweep. Potential limit (V) [ -5...+5 V ; -0.2 V ] Voltage limit for PSA sweep. Maximum time (s) [ > 0 ; 20 s ] Time limit for PSA sweep.
3.2 VA measurement modes AC – Alternating Current Voltammetry General: AC or Alternating Current voltammetry is primarily suitable for reversible electrode reactions. It is virtually completely insensitive to irreversible reactions. The AC measurement mode can be set for the exploratory and determination mode by selecting AC - Alternating current voltammetry for the Mode parameter in the EXPLORATORY SPECIFICATION or WORKING METHOD SPECIFICATIONS window.
3 General settings for exploratory and determination mode Sweep parameters: Hydrodynamic (measurement) [ on, off ; off ] Enable/disable stirring of the RDE/SSE during the sweep. Start potential (V) [ -5...+5 V ; -0.9 V ] Start voltage for the voltage sweep. End potential (V) [ -5...+5 V ; -0.1 V ] Final voltage for the voltage sweep. Voltage step (V) [ > 0 V ; 0.006 V ] Voltage step for direct voltage ramp. Voltage step time (s) [ > 0 s ; 0.
3.2 VA measurement modes Voltage step time > Modulation time + 450 ms (HMDE/RDE) Voltage step time > Modulation time + 470 ms (DME) Voltage step time > Modulation time + Drop size * 40 ms + 450 ms (SMDE) • • Modulation time > 2 / Frequency The measurement time t (i) is defined as follows: t (i) = Modulation time / 2 CVS - Cyclic Voltammetric Stripping General: CVS or Cyclic Voltammetric Stripping is used to determine organic additives in electroplating electrolytes.
3 General settings for exploratory and determination mode Sweep parameters: Hydrodynamic (measurement) [ on, off ; on ] Enable/disable stirring of the RDE/SSE during the sweep. Start potential (V) [ -5...+5 V ; 1.625 V ] First turning point for the potential sweep. Note: The Start potential needs to be between the First vertex potential and the Second vertex potential. First vertex potential (V) [ -5...+5 V ; -0.175 V ] First turning point for the potential sweep. Second vertex potential (V) [ -5...
3.2 VA measurement modes CPVS - Cyclic Pulse Voltammetric Stripping General: CPVS or Cyclic Pulse Voltammetric Stripping is used to determine organic additives in electroplating electrolytes. The CPVS measuring mode can be set for the exploratory and determination mode by selecting CPVS - Cyclic Pulse Voltammetric Stripping for the Mode parameter in the EXPLORATORY SPECIFICATION or WORKING METHOD SPECIFICATIONS window. Description: For Cyclic Pulse Voltammetric Stripping, the potential of an RDE (e.g.
3 General settings for exploratory and determination mode Sweep parameters: Hydrodynamic (measurement) [ on, off ; on ] Enable/disable stirring of the RDE/SSE during the sweep. Equilibration potential (V) [ -5...+5 V ; 0.45 V ] Voltage applied to the electrodes during the Equilibration time. Equilibration time (s) [ 0...80600 s ; 5 s ] During that time, the Equilibration potential is applied to the electrodes.
3.3 Potentiostat Notes: • The CPVS measurement mode can only be used with RDE electrodes. • The measurement time t (i) is defined as follows: Interval time ≥ 100 ms → t (i) = 20/16.67 ms (power frequency 50/60 Hz) Interval time < 100 ms → t (i) = Interval time / 4 3.3 Potentiostat The potentiostat built-in in the 797 VA Computrace stand normally works with full sensitivity for current measurements from 5 pA to 80 mA.
3 General settings for exploratory and determination mode Current range Voltage step time 10 nA > 50 ms 100 nA > 5 ms > 0.5 ms 1 μA > 0.5 ms 10 μA > 0.5 ms 100 μA 1 mA > 0.5 ms 10 mA > 0.5 ms * CV and CVS: Voltage step time = Voltage step / Sweep rate ** SqW: 3.4 Voltage step time = 1 / Frequency General operation sequence Overview of operation sequence The general operation sequence for measurements is identical for both the exploratory and the determination mode and includes the following steps: 1.
3.4 General operation sequence urement) is not checked, the stirrer is switched off during that time (details see Pretreatment). 9. Voltage sweep Start of the voltage sweep which depends on the selected measurement mode (details see VA measurement modes, section 3.2). 10. Stand-by potential Optional apply of a Stand-by potential before the start and after the end of the voltage sweep (details see Stand-by potential).
3 General settings for exploratory and determination mode Time of inert gas purging before the first measurement of the sample solution. Conditioning of solid state electrodes Solid state electrodes (particularly carbon electrodes) can be electrochemically regenerated by a freely selectable number of conditioning cycles. For every cycle, the voltage is changed at a sweep rate of 1 V/s to the end potential and then decreased at the same rate back to the start potential. Start potential (V) [ -5...
3.4 General operation sequence Cleaning potential (V) [ -5...+5 V ; -0.1 V ] Voltage applied to the electrodes during the Cleaning time. Cleaning time (s) [ 0...80600 s ; 0 s ] Time during which the Cleaning potential is applied to the electrodes. Deposition potential (V) [ -5...+5 V ; -0.9 V ] Voltage applied to the electrodes during the Deposition time. Deposition time (s) [ 0...80600 s ; 60 s ] Time during which the Deposition potential is applied to the electrodes. Equilibration time (s) [ 0...
3 General settings for exploratory and determination mode 3.5 Graphical settings Curve window elements All curve windows in the EXPLORATORY CURVES window, the DETERMINATION CURVES window and in the MONITOR window have the same elements which can be changed as desired in the GRAPHICAL PROPERTIES and the LINE PROPERTIES window (see below). Page properties The page properties of all curve windows can be set with the page tab of the GRAPHICAL PROPERTIES window.
3.5 Graphical settings Borders Top [ ≥ 0 pt ; 40 pt (for determination curves)] Left [ ≥ 0 pt ; 60 pt (for determination curves)] Right [ ≥ 0 pt ; 20 pt (for determination curves)] Bottom [ ≥ 0 pt ; 35 pt (for determination curves)] Border size in points (distance between the curve window frame and the graphical window frame inside the curve window). Colors Color of border in the curve window. Color of curve background in the curve window. Color of frame of the curve window.
3 General settings for exploratory and determination mode Range (for x axis) From [ -5...+5 ; -1 V ] Lower limit for x axis (voltage) (t(s) for CPVS, U(V) for all other measurement modes) To [ -5...+5 ; -1 V ] Upper limit for x axis (voltage) (t(s) for CPVS, U(V) for all other measurement modes) Range (for y axis) From [ > 0 ; -1e-10 ] Lower limit for y axis (dt/dU (s/V) for PSA and CCPSA; I(A) for all other measurement modes).
3.5 Graphical settings Format Format for labels of the x or y axis. Check one of the following options: Decimal ± ##.### (floating point number) Scientific ± #.### e ± ### Engineering ± ###.## + prefix Precision [ ≥ 0 ; 3 ] Total number of significant digits for labels of the x or y axis. Ticks Definition of major and minor ticks for x or y axis. No. [ ≥ 0 ; 8 ] Number of major or minor ticks for x or y axis.
3 General settings for exploratory and determination mode Type Line Connect the measurement points by a straight line. Scattered Draw a symbol for each measurement point. Both Connect the measurement points by a straight line and draw a symbol for each point. Line style Selection of line style of the curve in the LINE PROPERTIES window (see section 3.5 Line properties). General Drop line Draw vertical lines between each measurement point of the curve and bottom x axis.
3.5 Graphical settings Color of the line.
4 Exploratory mode 4 Exploratory mode 4.1 Exploratory mode overview Exploratory mode features The program part "Exploratory" has been especially designed for practice-oriented qualitative voltammetric analysis. It comprises ten different measurement techniques and is curve oriented. You are shown voltammograms and the associated parameters in two windows next to each other. The various voltammograms can be superimposed on one another thus making comparison of the curves extremely simple.
4.2 Exploratory specification window 4.2 Exploratory specification window Exploratory specification settings The EXPLORATORY SPECIFICATION window contains all settings for performing measurements in the exploratory mode. Most of the settings are identical for exploratory and determination mode and are therefore described in section 3. Signal Selection of a signal file to be shown with the Selected signal properties. As long as a signal is selected, the settings can not be edited.
4 Exploratory mode Drop size see Electrodes, section 3.1 Stirrer see Stirring, section 3.4 see Potentiostat, section 3.3 Initial purging time (Initial mixing time with CVS and CPVS) see Purging section 3.4, and Initial mixing time with CVS and CPVS section 6.3) Conditioning cycles see Conditioning of solid state electrodes section 3.4, and Conditioning cycles with CVS and CPVS section 6.3 Pretreatment see Pretreatment section 3.4, and Pretreatment with CVS and CPVS section 6.
4.2 Exploratory specification window EXPLORATORY SPECIFICATION / File / Export voltammetric parameters ... Save the voltammetric parameters of the current signal loaded in the working memory into an ACSII file (extension *.txt). The files can be imported into spreadsheet programs like Microsoft Excel or into text programs like Microsoft Word. Transfer parameters and data Measurement parameters and/or data points of signal files can be transferred between the exploratory mode and the determination mode.
4 Exploratory mode For the running voltage sweep there is a live display in the EXPLORATORY CURVES window with automatic scaling of the axes. Manual rescaling can be done by pressing the button. The red light at the left side of the button indicates a current overload. In this case, stop the measurement and change the measurement parameters. In the second line of the status window comments or error messages concerning the running measurement are displayed.
4.3 Exploratory curves If a signal file is loaded or measured, the axes have the following orientation: x axis The previously loaded or measured signal is displayed from the left to the right. For cyclic sweeps, the forward sweep is displayed from the left to the right. y axis The y axis is displayed with positive values at the top. Load signal curves The signal curves are loaded into the EXPLORATORY CURVES window by loading the signal files (*.sig) in the EXPLORATORY SPECIFICATION window.
4 Exploratory mode Zooming Curve regions in the EXPLORATORY CURVES window can be enlarged by zooming the desired area while pressing the left mouse button ("drag a box"; reset see Auto scaling). Auto scaling EXPLORATORY CURVES / Plot / Auto scale (F4) Reset zooming and scale x and y axes so that all measurement points of all signal curves are visible. This function is also active during measurement for the live display.
4.3 Exploratory curves Note: The line properties for axis or signal curve lines can be set with in the LINE PROPERTIES window (details see Line properties, section 3.5) Copy to clipboard EXPLORATORY CURVES / Plot / Copy to clipboard Copy the current content of the EXPLORATORY CURVES window to the clipboard. Save as enhanced metafile EXPLORATORY CURVES / Plot / Save as enhanced metafile Saves the current content of the EXPLORATORY CURVES window as an enhanced metafile (*.emf).
4 Exploratory mode Move cursor to the next or to the preceding measurement point on the selected signal. Peak search Automatic or manual peak evaluation of recorded signal curves. The results (peak position, height, area, derivative) are listed in the table of results, the calculated baselines and peak positions are also displayed in the EXPLORATORY CURVES window. EXPLORATORY SPECIFICATION / Signal / Peak search Open the PEAK SEARCH window for starting the quantitative peak evaluation.
4.3 Exploratory curves General parameters for peak evaluation. Options Manual Manual peak evaluation. The base points for baseline evaluation must be set manually. Automatic Automatic peak evaluation. The base points for baseline evaluation are evaluated automatically. Reverse peak Enable peak evaluation of reverse peaks (peaks with opposite direction compared to the sweep direction: negative peaks with anodic sweeps; positive peaks with cathodic sweeps).
4 Exploratory mode Baseline Parameters for baseline evaluation. Begin (V) (for CPVS: s) [ Start potential...End potential ; - ] Manual setting of the start base point for baseline evaluation. The values can be increased or decreased by clicking the buttons of the field or by clicking the field and pressing the ↑ or ↓ key. If the automatic peak evaluation is selected, n/a is displayed and the field can not be edited. End (V) (for CPVS: s) [ Start potential...
4.3 Exploratory curves Table of results Display of peak evaluation results. No. Number of evaluation result. This number is also displayed in the EXPLORATORY CURVES window. Clicking this number with the right mouse button offers the following menu: Edit baseline Open the EDIT BASELINE window for further modifying the peak evaluation for the selected peak (see Edit baseline, section 4.3). Copy Copy the selected results line of the table to the clipboard.
4 Exploratory mode Charge (C) Calculated charge transmitted during this peak (is depending from sweep rate and current). Edit baseline Modify the peak evaluation of an already found peak. The results are displayed in the PEAK SEARCH window. This window is opened by clicking the number of a found peak in the PEAK SEARCH window with the right mouse button and selecting the menu point Edit peak. Begin Manual setting of the start base point for baseline calculation.
4.3 Exploratory curves Wave evaluation Automatic wave evaluation of recorded DC or NP signal curves. The results (position of half-wave potentials and wave height) are listed in the table of results, the calculated tangents and positions of the half-wave potential are displayed in the EXPLORATORY CURVES window. EXPLORATORY SPECIFICATION / Signal / Wave evaluation Open the WAVE EVALUATION window for starting the quantitative wave evaluation. General parameters for wave evaluation.
4 Exploratory mode calculated positions of the half-wave potentials and tangents are displayed in the EXPLORATORY CURVES window. Table of results Display of wave evaluation results. No. Number of evaluation result. This number is also displayed in the EXPLORATORY CURVES window. Clicking this number with the right mouse button offers the following menu points: Copy Copy the selected result line to the clipboard. Copy All or Copy Wave List Copy all result lines of the table to the clipboard.
4.4 Printing in exploratory mode With Print curves enabled, the content of the EXPLORATORY CURVES window is printed on the upper half of the page if the portrait format is selected for the printer or on the whole page, if landscape format is selected. With Print voltammetric parameters enabled, the voltammetric parameters defined in the EXPLORATORY SPECIFICATION window are printed. Curves and voltammetric parameters are always printed on separate pages.
5 Determination mode 5 Determination mode 5.1 Determination mode overview Determination mode features The program part "Determination" is used for quantitative voltammetric analysis of inorganic and organic substances. It comprises nine different measurement modes and the possibility for stripping techniques. Quantitative evaluation can be performed via standard addition or calibration curve.
5.2 Working method specifications already open) closed. It serves to start a determination using the working method and shows the live display of the running determination curves. MAIN WINDOW / Window / Determination curves (F8) The DETERMINATION CURVES window will be opened or (if it is already open) closed. It contains determination and calibration curves of the loaded determination and offers the possibility for recalculation and modification of the loaded determination.
5 Determination mode loaded in the working memory as an ASCII file (*.txt). This file can be imported into spreadsheet programs like Microsoft Excel or into text programs like Microsoft Word. Note: The default folder where methods are saved or loaded from is set in the User directories tab of the USER RIGHTS window. Working method specifications window The WORKING METHOD SPECIFICATIONS window contains the main specifications for the working method (method loaded in the working memory).
5.2 Working method specifications Calibration [ see below ; Standard addition manual ] Selection of calibration mode (see also Calibration techniques with CVS and CPVS, section 6.2): Standard addition Standard addition. The number of additions is defined in the Determination tab, the standard addition solutions are defined in the Substances tab, and the Dosing Devices are defined in the DOSINOS window. Sample with calibration curve Sample determination using previously recorded calibration curves.
5 Determination mode Addition [ Manual, Automatic ; Manual ] Selection of manual or automatic standard addition or recording of calibration curves: Manual Manual standard addition resp. recording of calibration curves using a pipette. Automatic Automatic standard addition resp. recording of calibration curves using one or several Dosing Devices. Electrode Selection of electrode (see Electrodes, section 3.1). Drop size Drop size for SMDE or HMDE (see Electrodes, section 3.1).
5.2 Working method specifications Sample identifier [ 32 characters ; "sample" ] Identification for sample. The Note: The Sample identifier is used for the file name.
5 Determination mode Cell volume (mL) [ > 0 mL ; 10 mL ] Total volume of solution (sample + auxiliary solution, e.g. buffer (added manually or pre-dosed with a Dosing Device)) in the measuring vessel at the start of the determination. The sample concentrations Conc. calculated refer to this cell volume. Note: The sample and solution parameters (Sample identifier, Sample amount, Sample unit, Cell volume) are different with the CVS or CPVS mode.
5.2 Working method specifications No. of cells [ 0...28 ; 2 ] Number of solutions to be measured if Batch with solution exchange is selected for Technique. Calibration curve [ path + file name ; ] Selection of the determination file that contains the desired calibration curves. Accessible if Sample with calibration curve is selected for Calibration. Also accessible with Calibration technique “DT Suppressors with calibration curve” in the CVS and CPVS mode.
5 Determination mode For a detailed description of these parameters see section 3.4 General operation sequence, and section 3.2 VA measurement modes. If you work with the electroplating bath modes CVS or CPVS, see section 8.6 Operate a sequence in Electroplating Bath VA. Note: For Calibration technique "Sample with calibration curve" the Voltammetric tab parameters are not editable.
5.2 Working method specifications pend on the Calibration technique selected in the WORKING METHOD SPECIFICATIONS window. Substance [ 24 characters ; ] Substance name. For the assignment of a found peak to this substance the checkbox on the left side of the substance name must be checked. Peak pos. +/- (V) [ -5...+5 V ; 0 V ] Position of the peak voltage for the substance and tolerance for this verification voltage. Bsln. Parameters for baseline evaluation (details see Baseline, section 5.2).
5 Determination mode Achtung: Dosino 1..3 refer to Dosinos connected to the 797 VA Computrace. Dosino 4...7 refer to Dosinos connected to the 846 Dosing Interface (to MSB 1...4). Conc. [ > 0 ; 0 ] Value for concentration of addition solution. Unit [ pg/L...g/L ; g/L ] Unit for concentration of addition solution. With the CVS or CPVS mode: [ fL/L...mL/L ; mL/L ] Volume (mL) [ > 0.01 mL / var ; 0 mL ] Addition volume.
5.2 Working method specifications libration curve or RC Record response curve is selected for Calibration. Linear Interpolation The regression is calculated with a linear interpolation through 2 points. This option is only available if Record calibration curve, DT Record calibration curve or RC Record response curve is selected for Calibration. Quadratic Interpolation The regression is calculated with a nonlinear curve.
5 Determination mode Note: If you work with the modes CVS or CPVS the parameter list is different. Baseline The BASELINE window contains the settings for baseline evaluation for a single "variation" measurement (= all replications of a sample, standard addition or calibration measurement) of a substance and button for the selected substance in is opened by clicking the the Bsln. column in the Substances tab of the EDIT WORKING METHOD PARAMETERS window. Auto.
5.2 Working method specifications Note: For Electroplating Bath VA, Metrohm recommends to use a horizontal baseline with a fixed Begin and End. Calculations The Calculations tab in the EDIT WORKING METHOD PARAMETERS window contains a table with all formulae used for the calculation of the final results for a substance. Substance Selection of the substance with its calculation formulae. Calculations Display of defined calculation formulae. Name Name of the calculation formula.
5 Determination mode Open the CALCULATION window for edition of the selected formula. Delete the selected formula. Note: There is no Calculation tab in the EDIT WORKING METHOD PARAMETERS window, if you work with the CVS or CPVS modes and the Calibration technique Standard addition plating bath. Calculation Window The CALCULATION window is opened if a new formula is added or an existing formula is edited on the Calculations tab of the EDIT WORKING METHOD PARAMETERS window.
5.2 Working method specifications EDIT WORKING METHOD PARAMETER/Determination tab. For Calibration techniques not related to the Electroplating Bath VA modes, following formula is quoted: Final Result Final result of the determination, displayed on the bottom of the result sheet. Conc. The determined sample concentration, obtained through measurements and internal standard addition calculations (displayed in the Substance part of the result sheet).
5 Determination mode For the Electroplating Bath VA Calibration technique “DT Record calibration curve” (to get the “Calibration factor” for Suppressor determination), following formula is quoted: Cal.factor Z Is the “Calibration factor” to calculate the Suppressor concentration in the bath. It is determined at the “Evaluation ratio”. The default unit of the Cal.factor Z is mL/L. For all internal calculations the unit mL/L is used even if the output unit has been changed.
5.2 Working method specifications Volume (mL) [ > 0.01 mL ; 0 mL ] Addition volume for each addition. Switch to the previous page of this window. Switch to the next page of this window.
5 Determination mode Documentation In the Documentation tab of the EDIT WORKING METHOD PARAMETERS window the elements for the automatic documentation printout at the end of the determination are defined. These settings belong to the method and are stored with it. Results Automatic printout of Full report or Short report. Font size Font size in points for report printout. Comment Automatic printout of the method comment defined in the accompanying field.
5.2 Working method specifications Working method Automatic printout of the method parameters of the working method in the working memory. Order [ 1...6 ; ] Order of printout for the element. Save final results as ASCII file Automatic storage of the full report into an ASCII file. Path Path for saving the selected report elements into an ASCII file. Use to change the path.
5 Determination mode Export final results as ASCII If this option is activated, the full report is exported as an ASCII-file. Folder Target folder for storing the ASCII-file with the selected report elements. The folder can be changed by clicking the button . Export final results as CSV If this option is activated, the full report is exported as a CSV-file. Folder Target folder for storing the CSV-file with the selected report elements. The folder can be changed by clicking the button .
5.2 Working method specifications Append If this option is activated, the new XML -file is appended to a (possibly) already existing CSV-file. Overwrite If this option is activated, the new XML -file overwrites a (possibly) already existing CSV-file. Export determination to Auto Database If this option is activated, the determintion data is exported to a database. Database Database in which the data is to be exported. The database can be selected by clicking the button .
5 Determination mode Use for predose [ on, off ; off ] Use of a Dosing Device for addition of an auxiliary solution (e.g. buffer, or VMS for automated electroplating bath analysis) at the start of the determination. Volume of predose (mL) [ > 0.01 mL ; 0 mL ] Volume of the auxiliary solution (e.g. buffer, or VMS for automated electroplating bath analysis) to be added at the start of the determination. This volume must be accounted for the calculation of the Cell volume.
5.3 Monitor Start determination The operation sequence (see section 3.4) defined in the working method is started. If the previous determination has not been saved, the SAVE CONFIRMATION window indicating Data in memory is not saved appears offering the following options: Start the new determination without saving the previous determination. Save the previous determination before starting the new determination. Cancel the start of a new determination.
5 Determination mode Stop determination Stop running determination immediately. Hold determination Interrupt running determination. Continue determination Continue an interrupted determination. Next step Break off the running step and go to next step of the operation sequence. Monitor determination Once the determination is started, the running determination is monitored in the MONITOR window. All steps of the operation sequence are listed in the upper field at the left side of the control buttons.
5.3 Monitor overload. In this case, stop the measurement and change the measurement parameters. For a running voltage sweep there is a live display in the MONITORING window with automatic scaling of the axes. Manual rescaling can be done by pressing the button or selecting the Auto scale option of the context sensitive menu. At the end of each voltage sweep, the recorded curve is copied into the DETERMINATION CURVES window.
5 Determination mode can be changed if desired. Cell volume (mL) [ > 0 mL ; 10 mL ] Total volume of solution (sample + auxiliary solution, e.g. buffer (manually or pre-dosed with a Dosing Device)) in the measuring vessel at the start of the determination. The calculated sample concentrations Conc. refer to this cell volume. Add the sample solution into the measuring vessel and press .
5.3 Monitor concentrations Conc. refer to this cell volume. It can be changed for the Calibration technique “Standard addition plating bath” if desired. Add the VMS solution into the measuring vessel and press . PLACE ELECTROLYTE This window appears in the Electroplating Bath VA with the Calibration techniques "RC Sample with response curve" und "RC Record response curve". The window displays date and time of the determination start and the title of the method used.
5 Determination mode with the Calibration technique “MLAT Standard addition for brighteners”. The window displays date and time of the determination start and the title of the method used. Date and time in the format YYMMDDHHMM (month-day-hour-minute) and the Sample ID are used as default for the name of the determination file to be saved automatically (e.g. 0706181712_sample.dth). Sample ID [ 32 characters ; "sample" ] Identification for sample.
5.3 Monitor The window displays date and time of the determination start and the title of the method used. Date and time in the format YYMMDDHHMM (month-day-hour-minute) and the Sample ID are used as default for the name of the determination file to be saved automatically (e.g. 0706181712_sample.dth). Sample ID [ 32 Zeichen ; "sample" ] Identification for sample. The expression defined in the Determination tab is displayed and can be changed if desired.
5 Determination mode The window displays date and time of the determination start and the title of the method used. Date and time in the format YYMMDDHHMM (month-day-hour-minute) and the Sample ID are used as default for the name of the determination file to be saved automatically (e.g. 0706181712_sample.dth). Sample ID [ 32 characters ; "sample" ] Identification for sample. The expression defined in the Determination tab is displayed and can be changed if desired.
5.3 Monitor Calibration curve id [ 32 characters ; "sample" ] Identification for calibration curve. Add the calibration solution into the measuring vessel and press . MANUAL ADDITION This window appears at the start of each manual addition of standard solutions for standard addition determinations or the recording of calibration curves. Add (from solution no. X) (ml) [ > 0.
5 Determination mode ERTIES window (details see Axis properties, sec- tion 3.5). MONITORING / Curve properties The properties of the live curve can be set with the Monitor curve tab of the GRAPHICAL PROPERTIES window (details see Curve properties, section 3.5). Copy to clipboard MONITORING / Copy to clipboard Copy the current live curve in the MONITORING window to the clipboard. 5.4 Determination curves Load/save determinations Determination files (*.
5.4 Determination curves Save the current calibration curve loaded in the working memory in a new file. Enter name and directory for storage of the calibration curve file. If the file name already exists, windows asks if you want to overwrite the existing file. MAIN WINDOW / File / Save response curve (only accessible, if "RC Record response curve" is chosen for Calibration on the WORKING METHOD SPECIFICATION window) Save the current response curve loaded in the working memory.
5 Determination mode *.xml. This file can be imported into spreadsheet programs like Microsoft Excel (*.txt und *.csv) or in a LIMS (*.csv and *.xml). Copy parameters to working method DETERMINATION CURVES / Edit / Copy parameters to working method Copy the parameters of the loaded determination method into the WORKING METHOD SPECIFICATIONS window (working method). Determination curves window The DETERMINATION CURVES window shows the determination and calibration curves of the loaded determination.
5.4 Determination curves List of curves The top subwindow lists all available curves of the determination with the evaluated peak heights or peak charges . Determination curves The lower left subwindow shows a single or all determination curves. Calibration curves At the right side of the determination curves, there are eight subwindows for display of each substance calibration curve.
5 Determination mode Title [ 0...68 characters ; "Method title" ] Method title. Remark1 [ 0...68 characters ; ] Remark 1 regarding the method. Remark2 [ 0...68 characters ; ] Remark 2 regarding the method. Calibration [ read only ] Display of the calibration mode used for the determination (details see Working method specifications window, section 5.2). Technique [ read only ] Display of the measurement technique used for the determination (details see Working method specifications window, section 5.
5.4 Determination curves Electrode [ read only ] Display of electrode used (details see Electrodes, section 3.1). Stirrer [ read only ] Display of stirrer settings used (details see Stirring, section 3.4). Drop size [ read only ] Display of drop size used (details see Electrodes, section 3.1). Potentiostat [ read only ] Display of potentiostat settings used (details see Potentiostat, section 3.3).
5 Determination mode EDIT WORKING METHOD WINDOW. Edit addition parameters DETERMINATION CURVES / Edit / Addition parameters / Draw Enable/disable the drawing of the curve selected in list of curves. The entry in the Draw column of the list is changed. DETERMINATION CURVES / Edit / Addition parameters / Draw selected Draw only the curves selected in the list of curves. The entries in the Draw column of the list are set to “No" for all other curves.
5.4 Determination curves Automatic Switch on/off the automatic peak baseline evaluation. Begin Manual setting of the start base point for baseline evaluation. The base point can be moved either by manually changing the voltage value (time for CPVS) in the first field or by clicking the buttons of the second field indicating the current value. This field can only be edited if Automatic is disabled. End Manual setting of the end base point for baseline evaluation.
5 Determination mode Auto scaling DETERMINATION CURVES / Plot / Auto scale (F4) Reset zooming and scale x and y axes so that all measurement points of all determination curves are visible. Swap axis DETERMINATION CURVES / Plot / Swap axis / abscissa Swap x axis for the current determination curve. DETERMINATION CURVES / Plot / Swap axis / ordinate Swap y axis for the current determination curve.
5.4 Determination curves subwindow can be set with the page tab of the GRAPHICAL PROPERTIES window (see Page properties, section 3.5). The properties of the x and y axis can be set with the x axis and y axis tab of the GRAPHICAL PROPERTIES window (see Axis properties, section 3.5). DETERMINATION CURVES / Plot / Properties / Blank The properties of the blank curve can be set with the Blank tab of the GRAPHICAL PROPERTIES window (details see Curve properties, section 3.5).
5 Determination mode following options of the context sensitive menu (click right mouse button). DETERMINATION CURVES / Copy to clipboard Copy the content of the selected subwindow to the clipboard. DETERMINATION CURVES / Save as enhanced metafile Copy the content of the selected subwindow as enhanced metafile in the desired directory.
5.5 Results 5.5 Results Results window overview The RESULTS window contains the current full report for the loaded determination. If the determination is recalculated, the RESULTS window is automatically renewed.
5 Determination mode The RESULTS window comprises the following parts: Header Metrohm 797 VA Computrace Name of manufacturer and instrument. (Version w1.3.x) Version number of PC software. (Serial No.) Serial number of the instrument. Determination data Determination Name of determination file. Sample ID Identification for sample (see Sample identifier on the Determination tab). Creator method Name of the logged-in user who created the method the determination was done with. Creator determ.
5.5 Results Note: With the electroplating bath modes CVS and CPVS, and the Calibration technique "LAT Record intercept value" Volume Intercept Solution is indicated instead of Sample amount. Note: With the electroplating bath modes CVS and CPVS, and the Calibration techniques "LAT Standard addition for brighteners", "MLAT Standard addition for brighteners" and "RC Sample with response curve" Volume prod. bath is displayed instead of Sample amount.
5 Determination mode i.delta; P.delta; delta; Q.delta(Only with modes CVS and CPVS) Difference of two successive mean values of the evaluation quantities. Comments Display of comments if any type of error appeared in the sweep (e.g. Ovl. in scan = Overload during sweep; Ovl. in CDE = Overload during cleaning or deposition; Ovl. in cond. cycles = Overload during conditioning cycles; No peak found = no peak found for defined substance; Not used = peak is not used for calculation).
5.5 Results predose volume (mL) If the Dosing Device is used for solution predose, the message Predose X.X mL is displayed in this column. Electrode test Shows the status of the electrode test before the determination. Note: With the electroplating bath modes CVS and CPVS, and the Calibration techniques "MLAT Standard addition for brighteners" and "RC Sample with response curve", dosed volume after sample transfer (mL) is displayed additionally.
5 Determination mode 5.6 Sample table The SAMPLE TABLE window shows the sample data of the loaded sample table. With 863 Compact VA Autosampler: With 838 Advanced Sample Processor: Pos. [ for 863: 1, 3, 5 ... 127; read only ] [ for 838: 1, 2, 3 ... 112; read only ] Position of the sample on the sample rack. For the 863 Compact VA Autosampler, only odd numbers are displayed, since for every sample, a vessel containing rinsing solution must be placed at the even sample rack positions.
5.6 Sample table Sample ID [ 32 characters ; "sample" ] Identification for sample. Amount [ > 0 ; 10 ] Amount of sample added to the measuring vessel. Unit [ mL, g ; mL ] Selection of unit for sample amount. Cell volume (mL) [ > 0 mL ; 10 mL ] Total volume of solution (sample + auxiliary solution, e.g. buffer) in the measuring vessel at the start of the determination. The sample concentrations Conc. refer to this cell volume. Method Selection of the method used for this sample.
5 Determination mode the sample table file or No to cancel saving. SAMPLE TABLE / File / Save As ... Save the current sample table loaded in the working memory in a new file. Enter name and directory for storage of the sample table file. If the file name already exists, windows asks if you want to overwrite the existing file. Edit sample table The addition of new rows or the modification of existing rows in the sample table is done in the sample table window using the or button.
5.7 Printing in determination mode 5.7 Printing in determination mode MAIN WINDOW / File / Print (Ctrl+P) Print reports and/or curves. The PRINT OPTIONS window appears for selection of the elements to be printed. Results Printout of Full report or Short report. Font size Font size in points for report printout. Comment Printout of the method comment defined in the accompanying field. Determination curves Printout of all determination curves. Calibration Printout of all calibration curves.
5 Determination mode Working method Printout of the method parameters of the working method in the working memory. Order [ 1...6 ; ] Order of printout for the element. Sample table Printout of the sample table. 5.8 Data processing and evaluation Data transfer After the start of a determination, the parameters of the current working method are copied into the determination method. The parameters necessary for the VA measurement are then sent from the PC to the VA Computrace via USB connection.
5.8 Data processing and evaluation and replication). This identification can be used to select the single sweeps for display. In connection with the measured value recording, the following rules apply to the sweeps: • The maximum number of variations (V) is limited to 29 (1 sample + 28 additions), the maximum number of replications (R) to 10. • The maximum number of measured values is memory limited.
5 Determination mode aid of these measured maxima and minima values, the Peak voltage and Peak width values are determined for each peak. After the peak detection a baseline is constructed. The Peak height is determined from the value of the peak maximum minus the value of the baseline at the position of the peak voltage.
5.8 Data processing and evaluation mined by the baseline parameters set for this substance in the BASELINE window (see Baseline, section 5.2). The following possibilities exist for baseline calculation: Linear Whole Peak Start Linear Front end End Exponential Whole Peak Polynomial Whole Peak Start Linear Rear end End Start Horizontal Whole Peak End Start End As default, the start and end base points of the baselines are calculated automatically.
5 Determination mode Voltammogram i Chronoamperogram Peak area / Coulometric i Peak area / Coulometric Peak height U t di/dU Derivative U Peak voltage Comparing the evaluation quantities Area and Coulometric you have to consider the differences between voltammograms and chronoamperograms: Voltammogram: • Area is Power (Voltage * Current): • Coulometric is Charge (Voltage * Current / Sweep rate): V*A =W V*A/(V/s) = A*s = C Chronoamperogram: • Area is Charge (Current * time): • Coulometric i
5.8 Data processing and evaluation c(s) = Amount / Sample amount Note: With the electroplating modes CVS and CPVS different Calibration techniques are used. Dilution calculation In all cases in which the sample volume is diluted in the measuring vessel (e.g.
5 Determination mode mean(n) Mean value of all evaluation quantities for spiked sample n Std.dev.(n) Standard deviation of the individual value EV(n) = s(n) c(n) – c(s) Difference in the mass concentrations between the spiked sample n and the original sample solution 3.
5.8 Data processing and evaluation Rules for standard addition Standard addition is the usual calibration technique for the majority of the applications possible with the 797 VA Computrace. Its advantage lies in its high dependability as the calibration in the sample takes place under real matrix conditions and all measurement parameters remain unchanged.
5 Determination mode Linear Regression: 2 ≥3 Nonlinear Regression: 3 ≥5 Linear Regression (through Zero): 1 ≥2 Nonlinear Regression (through Zero): 2 ≥4 Linear Interpolation: 2 ≥2 Quadratic Interpolation: 3 ≥5 If less than the "Recommended number" of calibration points are used for the calculation, the regression curve might does not fit ideally. Therefore you should always use the "Recommended number" of calibration points.
5.8 Data processing and evaluation y = a + b x+ c x 2 Nonlinear curve 2nd degree = Quadratic Regression The parameters a, b and d of the regression curves are calculated by weighted least square minimization with y = EV and x = c(eff). The weight factor for each point is the standard deviation obtained from the replications. The parameters are displayed in the RESULTS window and have the following meaning: a = Y.
5 Determination mode EV Sample mean(s) c(s) c(eff) 5. Calculation of result deviation Conc.dev. The total deviation of the calculated substance concentration Conc. is determined using a linear error calculation which takes into account both the error contribution from the measurement and that from the calibration. Independent of the number of measurements, the total deviation Conc.dev. is always calculated in a way that Conc. ± Conc.dev.
5.8 Data processing and evaluation • Determining the working range The calibration curve is defined only for the range between the calibration solutions with the lowest and highest mass concentrations. Extrapolations outside this range are not allowed. • Keep temperature constant Owing to the large temperature dependence of the measured values (≥ 2%/°C), it is advisable to work with the 6.1418.220 thermostatted measuring vessel.
6 Electroplating Bath VA 6 Electroplating Bath VA 6.1 Electroplating Bath VA – Introduction The 797 VA Computrace has two special modes for electroplating bath analysis: CVS (Cyclic Voltammetric Stripping) and CPVS (Cyclic Pulse Voltammetric Stripping). Working with these two modes, you have to consider that some settings and options differ from working with the other modes. 6.
6.2 Calibration techniques with CVS and CPVS determination. The parameters displayed depend on the selected Calibration technique and measurement Technique. With “Standard addition plating bath” following parameters have to be defined: Sample identifier [ 32 characters ; "sample" ] Identification for sample. The Sample identifier is used for the file name. Cell volume (mL) [ > 0 mL ; 10 mL ] Total volume of solution (e.g. Virgin Make-up Solution, see VMS (Virgin Make-up Solution), section 6.
6 Electroplating Bath VA ment). For cyclic modes (CV, CVS, CPVS) the “total number of measurements” is the No. of replications multiplied with the number of Save last .. sweeps (Voltammetric tab). “Total number of measurements” must not exceed 10. Voltammetric tab with Calibration technique “Standard addition plating bath” The Voltammetric tab of the EDIT WORKING METHOD PARAMETERS window contains parameters for preparation procedures and VA measurement modes.
6.2 Calibration techniques with CVS and CPVS CVS - Cyclic Voltammetric Stripping section 3.2, and CPVS - Cyclic Pulse Voltammetric Stripping section 3.2) Substances tab with Calibration technique “Standard addition plating bath” The Substances tab of the EDIT WORKING METHOD PARAMETERS window contains parameters for the definition and recognition of substances, for the definition of standard solutions, for peak evaluation and results calculation.
6 Electroplating Bath VA Volume (mL) [ > 0.01 mL / var ; 0 mL ] Addition volume. For entering variable addition volumes, click the button to open the EDIT VARIED ADDITION window for the selected substance (details see Variable addition, section 5.2). In this case, var is entered into the field instead of a fixed value. This field only appears once for solutions with the same number (mixed standards) and it is not displayed if 0 is entered as solution number.
6.2 Calibration techniques with CVS and CPVS Note: A determined "Intercept value" can only be adopted automatically, if the checkbox Save calibration curves additionally without date and time on the General tab of the GENERAL SETTINGS window is checked. Determination tab with Calibration technique “LAT Record intercept value” The Determination tab of the EDIT WORKING METHOD PARAMETERS window contains general specifications for performing the determination.
6 Electroplating Bath VA Note: If you set a small value (e.g. < 1%), it can take a long time until reaching the target. Note: If both No. of conditioning measurements [ 1...100 ; 1 ] and Auto Std.dev (%) [ >0.1 ; 1 ] are activated, the conditioning is finished as soon as the first of the two criterias is reached. No. of replications [ 1...10 ; 2 ] Number of replications (= total number of measurements) for each variation (sample, standard addition, calibration level, conditioning measurement).
6.2 Calibration techniques with CVS and CPVS Cleaning time (s) [ 0...80600 s ; 0 s ] Time during which the Cleaning potential is ap- plied to the electrodes. [ -5...+5 V ; 1.625 V ] (This parameter is with CPVS part of the sweep) Voltage applied to the electrodes during the Equilibration time. Equilibration potential (V) Equilibration time (s) [ 0...
6 Electroplating Bath VA Area Peak area between peak curve and calculated baseline. Derivative Difference between positive an negative maximum of the first derivative of the voltammogram. Coulometric Charge transmitted during the peak. Smooth factor [ 1...6 ; 4 ] Smoothing power of the Savitzky/Golay smoothing of the baseline (1 = minimum smoothing, 6 = maximum smoothing) (see Smoothing and differentiation, section 5.8). Eliminate spikes Eliminates spikes to smooth the signal.
6.2 Calibration techniques with CVS and CPVS Standard addition for brighteners” following parameters have to be defined: Sample identifier [ 32 characters ; "sample" ] Identification for sample. The Sample identifier is used for the file name. Volume production bath (mL) [> 0 mL ; 10 mL] The volume of sample bath solution added (see Production bath solution, section 6.4).
6 Electroplating Bath VA on the General tab of the GENERAL SETTINGS window is checked. Initial electrode conditioning (see Initial electrode conditioning, section 6.3) Check the checkbox to use conditioning. No. of conditioning measurements [ 1...100 ; 1 ] Number of replications of conditioning measurements. The “total number of conditioning measurements” is the No. of conditioning measurements multiplied with the number of Save last .. sweeps (Voltammetric tab).
6.2 Calibration techniques with CVS and CPVS VA measurement modes. The parameters displayed depend on the measurement mode selected in the WORKING METHOD SPECIFICATIONS window. With “LAT Standard addition for brighteners” following parameters have to be defined: Initial mixing time (s) [ 0...80600 s ; 10 s ] (see Initial mixing time with CVS and CPVS, section 6.3) Time of mixing before the first measurement of the sample solution.
6 Electroplating Bath VA SPECIFICATIONS window. With “LAT Standard addition for brighte- ners” following parameters have to be defined: Substance [ 24 characters ; ] Substance name. For the assignment of a found peak to this substance the checkbox on the left side of the substance name must be checked. With CVS: Peak pos. +/- (V) [ -5...+5 V ; 0 V ] Position of the peak voltage for the substance and tolerance for this verification voltage. With CPVS: Step potential [ read only ; step 1: 0.
6.2 Calibration techniques with CVS and CPVS Contamination potential [ -5...5 ; 1.125 V ] With CVS: If it is activated, the current is readout for the defined potential during the last sweep (in anodic direction) of the bath determination. With CPVS: One of the defined stripping steps (Voltammetric tab with Calibration technique "LAT") can be selected. If it is activated, the current is readout for the selected potential during the last sweep (in anodic direction) of the bath determination.
6 Electroplating Bath VA Reverse sweep [ on, off ; off ] Enable peak evaluation of the reverse sweep of cyclic sweeps (not available with CPVS). MLAT Standard addition for brighteners Modified Linear Approximation Technique (“MLAT Standard addition for brighteners”) is a Calibration technique for CVS and CPVS. It is the standard technique to analyze Brighteners in electroplating baths.
6.2 Calibration techniques with CVS and CPVS saved sweeps of the last two “conditioning measurements”. Note: If you set a small value (e.g. < 1%), it can take a long time until reaching the target. Note: If both No. of conditioning measurements [ 1...100 ; 1 ] and Auto Std.dev (%) [ >0.1 ; 1 ] are activated, the conditioning is finished as soon as the first of the two criterias is reached.
6 Electroplating Bath VA Start potential (V) [ -5...+5 V ; 0.2 V ] Start voltage for the cyclic conditioning sweep. End potential (V) [ -5...+5 V ; 1.625 V ] Final voltage for the cyclic conditioning sweep. No. of cycles [ 0...X ; 0 ] Number of conditioning cycles. Pretreatment (see Pretreatment with CVS and CPVS, section 6.3) Cleaning potential (V) [ -5...+5 V ; 1.625 V ] Voltage applied to the electrodes during the Cleaning time. Cleaning time (s) [ 0...
6.2 Calibration techniques with CVS and CPVS With CPVS: Step potential [ read only ; step 1: 0.2 V ] Displays the potential values, which are defined in the window edit stripping steps. Bsln. Parameters for baseline evaluation (details see Baseline, section 5.2). Click the button to open the BASELINE window for the selected substance. Additive solution Definition of addition solutions for standard addition. No. [ 0...8 ; 0 ] Number of addition solution used for manual or automatic addition.
6 Electroplating Bath VA Chloride potential [ -5...5 ; 1.475 V ] With CVS: If it is activated, the current is readout for the defined potential during the last sweep (in anodic direction) of the bath determination. With CPVS: One of the defined stripping steps (Voltammetric tab with Calibration technique "MLAT") can be selected. If it is activated, the current is readout for the selected potential during the last sweep (in anodic direction) of the bath determination.
6.2 Calibration techniques with CVS and CPVS Note: A determined calibration curve can only be adopted automatically if the checkbox Save calibration curves additionally without date and time on the General tab of the GENERAL SETTINGS window is checked. Determination tab with Calibration technique “DT Suppressors with calibration curve” The Determination tab of the EDIT WORKING METHOD PARAMETERS window contains general specifications for performing the determination.
6 Electroplating Bath VA Note: If both No. of conditioning measurements [ 1...100 ; 1 ] and Auto Std.dev (%) [ >0.1 ; 1 ] are activated, the conditioning is finished as soon as the first of the two criterias is reached. Addition mixing time [ 0...80600 s ; 10 s ] Time of mixing after Additions (for the first measurement, the Initial mixing time is used). Calibration curve [ path + file name ; ] Define the calibration curve file (the file in which the determination of the calibration was(will be) saved).
6.2 Calibration techniques with CVS and CPVS sweeps (Voltammetric tab). “Total number of mea- surements” must not exceed 10. Voltammetric tab with Calibration technique “DT Suppressors with calibration curve” The Voltammetric tab of the EDIT WORKING METHOD PARAMETERS window contains parameters for preparation procedures and VA measurement modes. With the Calibration technique "DT Suppressors with calibration curve" the Voltammetric parameters are not editable.
6 Electroplating Bath VA and CPVS - Cyclic Pulse Voltammetric Stripping section 3.2) Substances tab with Calibration technique “DT Suppressors with calibration curve” The Substances tab of the EDIT WORKING METHOD PARAMETERS window contains parameters for the definition and recognition of substances, for the definition of standard solutions, for peak evaluation and results calculation. The parameters displayed depend on the Calibration technique selected in the WORKING METHOD SPECIFICATIONS window.
6.2 Calibration techniques with CVS and CPVS a fixed value. This field only appears once for solutions with the same number (mixed standards) and it is not displayed if 0 is entered as solution number. Regression technique Selection of regression technique: Linear Regression The regression is calculated with a straight line. Nonlinear Regression The regression is calculated with a nonlinear curve. Linear Interpolation The regression is calculated with a linear interpolation through 2 points.
6 Electroplating Bath VA DT Record calibration curve “DT Record calibration curve” is used to record calibration curves for the dilution titration calibration technique (with the CVS and CPVS mode). Dilution titration Calibration technique is mainly used to analyze Suppressors in electroplating baths. The calibration curves recorded with this Calibration technique are used to determine Suppressor concentrations with the Calibration technique “DT Suppressors with calibration curve”.
6.2 Calibration techniques with CVS and CPVS bration curves additionally without date and time on the General tab of the GENERAL SETTINGS window is checked. Volume VMS (mL) [ > 0 mL ; 10 mL] The volume of the Virgin Make-up Solution (see VMS (Virgin Make-up Solution), section 6.4). Cell volume (mL) [ > 0 mL ; 10 mL ] [ read only ] Total volume of solution (equal to the volume of the VMS (Virgin Make-up Solution)) in the measuring vessel at the start of the determination. The sample concentrations Conc.
6 Electroplating Bath VA cations multiplied with the number of Save last .. sweeps (Voltammetric tab). “Total number of measurements” must not exceed 10. Voltammetric tab with Calibration technique “DT Record calibration curve” The Voltammetric tab of the EDIT WORKING METHOD PARAMETERS window contains parameters for preparation procedures and VA measurement modes. With the Calibration technique "DT Record calibration curve" the Voltammetric parameters are not editable.
6.2 Calibration techniques with CVS and CPVS and CPVS - Cyclic Pulse Voltammetric Stripping section 3.2) Substances tab with Calibration technique “DT Record calibration curve” The Substances tab of the EDIT WORKING METHOD PARAMETERS window contains parameters for the definition and recognition of substances, for the definition of standard solutions, for peak evaluation and results calculation.
6 Electroplating Bath VA this case, var is entered into the field instead of a fixed value. This field only appears once for solutions with the same number (mixed standards) and it is not displayed if 0 is entered as solution number. Regression technique [ see below ; Linear Regression ] Selection of regression technique: Linear Regression The regression is calculated with a straight line. Nonlinear Regression The regression is calculated with a nonlinear curve.
6.2 Calibration techniques with CVS and CPVS ons are stopped and the “Calibration factor” is calculated. Evaluation ratio Q/Q(0) [ 0…1 ; 0.5] The “Evaluation ratio” defines the point of evaluation for the calculation of the “Calibration factor” Z. Begin of evaluation Q/Q(0) [ 0…1 ; 1.0] Only the measuring points between the „Begin of evaluation“ and the „Evaluation ratio“ are used for the calculation of the regression (linear, nonlinear and quadratic).
6 Electroplating Bath VA Add production bath to electrolyte [ on, off ; off ] If is activated, the Production bath solution is added to the Electrolyte solution. If it is not activated, the Electrolyte solution is siphoned off before the Production bath solution is placed into the the measuring vessel. Initial electrode conditioning (see Initial electrode conditioning, section 6.3) Check the checkbox to use conditioning. No. of conditioning measurements [ 1...
6.2 Calibration techniques with CVS and CPVS Example for Response curve: C:\User XYZ\Data\Response curve.dth Achtung: To make sure that for "Suppressor analysis with 838 Advanced Sample Processor and RC" always the latest response curve file is taken for the calculation, the path of the file chosen for Response curve, must match with the path defined for the parameter Data folder (for the currently logged-in user) on the tab User Directories of the window USER RIGHTS.
6 Electroplating Bath VA Pretreatment (see Pretreatment with CVS and CPVS, section 6.3) Cleaning potential (V) [ -5...+5 V ; 1.625 V ] [ read only ] Voltage applied to the electrodes during the Cleaning time. Cleaning time (s) [ 0...80600 s ; 0 s ] [ read only ] Time during which the Cleaning potential is ap- plied to the electrodes. [ -5...+5 V ; 1.625 V ] (This parameter is with CPVS part of the sweep) Voltage applied to the electrodes during the Equilibration time.
6.2 Calibration techniques with CVS and CPVS Regression technique [ read only ] The regression technique is displayed. Peak evaluation [ Coulometric ] [ read only ] Selection of peak evaluation quantity: Coulometric Charge transmitted during the peak. Smooth factor [ 1...6 ; 4 ] Smoothing power of the Savitzky/Golay smoothing of the baseline (1 = minimum smoothing, 6 = maximum smoothing) (see Smoothing and differentiation, section 5.8). Eliminate spikes Eliminates spikes to smooth the signal.
6 Electroplating Bath VA Sample identifier [ 32 characters ; "sample" ] Identification for sample. Note: The Sample identifier is used for the file name. To make sure that for "Suppressor analysis with 838 Advanced Sample Processor and RC" always the latest response curve file is taken for the calculation, this Sample identifier must match with the name of the calibration file defined for the parameter Response curve on the Determination tab with calibration "RC Record response curve".
6.2 Calibration techniques with CVS and CPVS or Auto Std.dev (%)[ >0.1 ; 1 ] Define until which „Std.dev.“ the conditioning is continued. The „Std.dev.“ is calculated from all saved sweeps of the last two “conditioning measurements”. Note: If you set a small value (e.g. < 1%), it can take a long time until reaching the target. Note: If both No. of conditioning measurements [ 1...100 ; 1 ] and Auto Std.dev (%) [ >0.
6 Electroplating Bath VA Start potential (V) [ -5...+5 V ; 0.2 V ] [ read only ] Start voltage for the cyclic conditioning sweep. End potential (V) [ -5...+5 V ; 1.625 V ] [ read only ] Final voltage for the cyclic conditioning sweep. No. of cycles [ 0...X ; 0 ] [ read only ] Number of conditioning cycles. Pretreatment (see Pretreatment with CVS and CPVS, section 6.3) Cleaning potential (V) [ -5...+5 V ; 1.625 V ] [ read only ] Voltage applied to the electrodes during the Cleaning time.
6.2 Calibration techniques with CVS and CPVS With CPVS: Step potential [ read only ; step 1: 0.2 V ] Displays the potential values, which are defined in the window edit stripping steps. Bsln. Parameters for baseline evaluation (details see Baseline, section 5.2). Click the button to open the BASELINE window for the selected substance. Suppressor standard solution Definition of addition solutions for standard addition. No. [ 0...8 ; 0 ] Number of addition solution used for manual or automatic addition.
6 Electroplating Bath VA Peak evaluation [ Height, Area, Derivative, Coulometric ; Coulometric ] Selection of peak evaluation quantity: Height Peak height from baseline to peak maximum. Area Peak area between peak curve and calculated baseline. Derivative Difference between positive an negative maximum of the first derivative of the voltammogram. Coulometric Charge transmitted during the peak. Smooth factor [ 1...
6.3 Different settings and options with CVS and CPVS • Determination parameters on the Determination tab of the EDIT WORKING METHOD PARAMETERS window are different (see Determination for other modes section 5.2, and check the parameters for the Calibration technique you are using Calibration techniques with CVS and CPVS, section 6.2) • Different Technique options (Batch with solution exchange is not applicable with CVS and CPVS, see also Working method specifications window section 5.
6 Electroplating Bath VA find it on the Voltammetric tab of the EDIT WORKING METHOD PARAMETERS window. Conditioning cycles with CVS and CPVS With CVS and CPVS the sweep is mainly in the positive voltage area. Therefore, the default values are positive (compare to Conditioning of solid state electrodes, section 3.4) Start potential (V) [ -5...+5 V ; 0.2V ] Start voltage for the cyclic conditioning sweep. End potential (V) [ -5...+5 V ; 1.575 V ] Final voltage for the cyclic conditioning sweep. No.
6.3 Different settings and options with CVS and CPVS Additional conditioning after sample transfer (only active with MLAT and RC Sample with response curve , and if Initial electrode conditioning is activated) If this option is activated, an additional electrode conditioning is started after sample addition. This option can only be activated, if Initial electrode conditioning is activated.
6 Electroplating Bath VA V.dev With Calibration technique “DT Record calibration curve”: Deviation of the volume of added Suppressor standard solution at the “Evaluation ratio”. With Calibration technique “DT Suppressors with calibration curve”: Deviation of the volume of added Production bath solution at the “Evaluation ratio”. Cal.
6.4 Some Definitions used with CVS and CPVS • Chloride potential • Calibration factor • Suppressor • Brightener • Electrolyte solution VMS (Virgin Make-up Solution) The VMS (Virgin Make-up Solution) is an electroplating bath solution like the one, which is analyzed. But it contains no organic additives and it is made from reagent grade chemicals. Note: The VMS solution should always be adjusted to the bath solution as exactly as possible.
6 Electroplating Bath VA Production bath solution The “Production bath solution” (or “Plating bath solution”) is the sample solution to be analyzed. It is used in the Electroplating Bath analysis with the modes CVS and CPVS. Addition ratio The “Addition ratio” is a certain Q/Q(0) ratio which defines the number of additions with the two “dilution titration technique” Calibration techniques “DT Record calibration curve” and “DT Suppressors with calibration curve” (with the modes CVS and CPVS).
6.4 Some Definitions used with CVS and CPVS Contamination potential The Contamination potential correlates with the concentration of organic degradation products in the electroplating bath. It is used with the Calibration techniques LAT Standard addition for brighteners and MLAT Standard addition for brighteners (with the modi CVS and CPVS). Chloride potential The Chloride potential correlates with the concentration of chloride in the electroplating bath.
6 Electroplating Bath VA Electrolyte solution The Electrolyte solution is a mixture of VMS and these additives, which are not to be determined (with "Response Curve Technique").
7.1 Computrace control 7 Manual control 7.1 Computrace control Computrace control selection MAIN WINDOW / Utility / Computrace control Start manual control of the 797 VA Computrace stand. Computrace control window The COMPUTRACE CONTROL window serves for manual control of the 797 VA Computrace stand. 10 mA ... 10 nA Selection of current range for measurement in the manual control mode. I ovl 797 VA Computrace – Software Indication of current overload by red light.
7 Manual control Switch on/off current measurement. If switched on, the set Potential is applied to the electrodes and the current is measured continuously. This mode is indicated by the red light beside the | button. Potential (V) [ -5...+5 V ; 0 V ] Voltage to be applied to the electrodes. Potential (V) [ read only ] Display of current voltage applied to the electrodes. Current (xA) [ read only ] Display of measured current. No electrode No electrode connected to the 797 VA Computrace stand. |
7.2 Dosing Device control 7.2 Dosing Device control Dosing Device control selection MAIN WINDOW / Utility / Dosino control Start manual control of the Dosing Devices (possible: 700/800 Dosino , 685/805 Dosimat) connected to the 797 VA Computrace stand or the 846 Dosing Interface. Dosino control window The DOSINO CONTROL window serves for manual control of the Dosing Devices connected to the 797 VA Computrace stand (under Dosing Processor) or the 846 Dosing Interface (under Dosing Interface). Dosino 1..
7 Manual control Dosed volume (mL) Dose the set volume. Switch on dosing by Dosing Device. The solution is dispensed until the button is pressed or the Dose volume (mL) is reached. The burette cylinder of the Dosing Device is filled. Fills burette cylinder and tubes. Used to remove air bubbles, solution exchange and cleaning. Used to empty the Dosino (not feasible with Dosimats). 7.
7.4 Film deposition Rinsing pump on (s) Rinse for so many seconds. Start with clicking , stop by clicking . Number of rinsing cycles Number of rinsing/siphoning cycles (after activating Rinse cell system). A cycle is siphoning and rinsing once. Length of siphoning and rinsing are defined in Siphoning pump on (s) and Rinsing pump on (s). Rinse cell system Siphon and rinse the cell system. Define settings in Number of rinsing cycles, Siphoning pump on (s) and Rinsing pump on (s).
7 Manual control Plating solution [ 48 characters ; ] Name of electrolyte solution used for film deposition. Stirrer/RDE (rpm) [ 0...3000 rpm ; 2000 rpm ] Revolutions per minute of the rotating disk electrode. The stirring of the RDE remains active during all preparation procedure steps until the start of the cleaning sweep. Purge time (s) [ 0...80600 s ; 300 s ] Time of inert gas purging before the first measurement of the sample solution.
7.5 Cleaning procedure Sweep Parameters of DP sweep used at the end of the film deposition for checking the electrode (see VA measurement modes, section 3.2). Cell off after measurement [ on, off ; on ] Enable/disable the switching off of the voltage applied to the electrodes after measurement. Stand-by potential (V) [ -5...+5 V ; -0.1 V ] Voltage to be applied to the electrodes after measurement if the Cell off after measurement box is set to off. 7.
7 Manual control Purge time (s) [ 0...80600 s ; 300 s ] Time of inert gas purging before the first measurement of the sample solution. Conditioning cycles Electrochemical regeneration of the solid state electrode by a freely selectable number of conditioning cycles. For every cycle, the voltage is changed at a sweep rate of 1 V/s to the End potential and then decreased at the same rate back to the Start potential. Start potential (V) [ -5...+5 V ; -1.2 V ] Start voltage for the cyclic conditioning sweep.
8.1 Installation and program start 8 How to ...? 8.1 Installation and program start Install Dosing Devices for automatic addition 1. Connect Dosing Devices (possible: 700/800 Dosino , 685/805 Dosimat) to the 797 VA Computrace stand or the 846 Dosing Interface (see Installation of Dosing Devices, section 1.3). 2. Make hardware settings for Dosing Devices. 3. Select Automatic for Addition in the WORKING METHOD SPECIFICATIONS window. 4.
8 How to ...? Note: If you switch off the instruments, switch off the 731 Relay Box first. 8.2 User rights Define a new user 1. Open the USER RIGHTS window by clicking on MAIN WINDOW / User / User rights. button to open the ADD NEW USER 2. Click the window. 3. Enter the Name and Password of the new user. 4. Close the ADD NEW USER window by clicking . 5. Select the new user in the list of all users and set his user rights (see User rights, section 2.6). 6.
8.3 Signals in exploratory mode Save a signal curve 1. Select the desired signal curve in the list of the EXPLORATORY SPECIFICATIONS window. 2. Click on nal. or EXPLORATORY SPECIFICATION / File / Save sig- 3. Select the desired directory and enter the signal file name *.sig in the SAVE AS window and click the button. Please note that a user specific data directory can be defined in the User Directories tab. Save signal curves automatically 1.
8 How to ...? 11. Start the measurement by clicking the icon or the button (see Performing exploratory measurements, section 4.2). Note: As soon as a signal curve is measured or loaded, the voltammetric parameter get read only. Should the parameters be changed before measuring a new signal curve, the button needs to be clicked. Evaluate signal peaks automatically 1. Select the desired signal file in the Signal field of the EXPLORATORY CURVES window.
8.4 Methods in determination mode 7. Click the button. The calculated baselines and peak maximum positions are displayed in the EXPLORATORY CURVES window. The evaluation results are displayed in the table of results in the PEAK SEARCH window. Evaluate signal waves 1. Select the desired signal file in the Signal field of the EXPLORATORY SPECIFICATION window. The selected signal curve is shown with the Selected signal properties. 2. Click on EXPLORATORY CURVES / Signal / Wave evaluation.
8 How to ...? Copy parameters from determination methods 1. Click on or MAIN WINDOW / Mode / Determination. 2. Click on or MAIN WINDOW / File / Load determination. 3. Select the desired determination file *.dth in the OPEN window and click . The determination is loaded into the DETERMINATION CURVES window. 4. Click on DETERMINATION CURVES / Edit / Copy parameters to working method. Copy parameters from signal files 1. Click on or MAIN WINDOW / Mode / Exploratory. 2. Click on signal.
8.5 Determinations with voltammetric trace analysis 6. If Dosing Devices should be used for addition or predose, click and set the parameters to the desired values (see Dosing Devices, section 5.2). and limit the Highest current 7. If necessary, click range or Lowest current range in the POTENTIOSTAT window (see Potentiostat, section 3.3). 8. Click and set the parameters on the tabs Determination, Voltammetric, Substances, Calculations, Documentation und Export (see section 5.
8 How to ...? 3. Select the desired determination file *.dth in the OPEN window and click . The determination is loaded into the DETERMINATION CURVES window. 4. If the method parameters of the loaded determination should be used for a new measurement, copy the determination method parameters to the working method by clicking on DETERMINATION CURVES / Edit / Copy parameters to working method. Save a determination 1.
8.5 Determinations with voltammetric trace analysis 8. Follow the instructions in the appearing message windows. Perform a test determination with the Pb test method With the aid of this example method for the determination of lead in the ion standard solution supplied using the DME, you can easily check whether the 797 VA Computrace System is functioning properly. 1. Click on or MAIN WINDOW / Mode / Determination.
8 How to ...? 15. Click the button. The determination is saved automatically if specified on the General tab of the GENERAL SETTINGS window and the result report is printed if specified on the Documentation tab of the EDIT WORKING METHOD PARAMETERS window. Perform determinations using the 863 Compact VA Autosampler 1. Install the 863 Compact VA Autosampler (see Installation of 863 Compact VA Autosampler, section 1.3) and set method 2. 2.
8.5 Determinations with voltammetric trace analysis 15. Follow the instructions in the appearing message windows. Note: If you want to measure all samples with the same working method, you can select Repeat current method for Working method source on the Automation tab of the GENERAL SETTINGS window. The SAMPLE TABLE window is not accessible with Repeat current method. Perform VA determinations using the 838 Advanced Sample Processor 1.
8 How to ...? 838 Advanced Sample Processor. You can use 50 mL sample vessels (on the two outer rings) or 11 mL sample vessels (on the two inner rings). Place the sample on the outer (e.g. position 1) of the two rings and the rinsing solution on the inner (e.g. position 29) of the two rings. Define the position of the first sample vessel for the 838 parameter "SAMPLE" with the 838 keypad. 13. Click on or MAIN WINDOW / Window / Monitor to open the MONITOR window. 14.
8.
8 How to ...? 13. If you want to save the modified determination under the same name, click on or MAIN WINDOW / File / Save determination. The old file will be overwritten. 14. If you want to save the modified determination under a new name, click on MAIN WINDOW / File / Save determination as. Select the desired directory, enter the determination file name *.dth in the SAVE AS window, and click the button. Print determination results and curves 1. Click on or MAIN WINDOW / File / Print.
8.6 Analyze Electroplating Bath Solutions “DT Suppressors with calibration curve” (used to determine the Sample) "Response Curve Technique" "RC Record response curve" (Used to record the response curve) "RC Sample with response curve” (Used to determine the sample) Choose the mode in Electroplating Bath VA To run Electroplating Bath VA, you can choose between 2 modes: CVS (Cyclic Voltammetric Stripping) and CPVS (Cyclic Pulse Voltammetric Stripping).
8 How to ...? 3. Add Brightener standard solution several times and measure Q(addition) for each addition. Usually, two or three standard additions are made for the determination of Brighteners. LAT "LAT Standard addition for brighteners" (and "LAT Record intercept value" to record the "Intercept value"). The second Calibration technique (should only be applied if "MLAT" is inapplicable) is "LAT Standard addition for brighteners".
8.6 Analyze Electroplating Bath Solutions 3. Define the No. of additions on the Determination tab of the EDIT WORKING METHOD PARAMETERS window. 4. Place the "Bath solution" into the sample vesseland click start. Q(Bath) is determined. 5. Add Brightener standard solution several times and measure Q(addition) for each addition. Normally, two or three standard additions should be done for the brightener determination.
8 How to ...? Typical standard addition scheme for "DT Suppressors with calibration curve": 1. Choose a previously recorded Calibration curve on the Determination tab of the EDIT WORKING METHOD PARAMETERS window. Use the button to search for the Calibration curve file. “Addition ratio” and “Evaluation ratio” are set automatically to the values used for recording the calibration curve. 2. Place the VMS (Virgin Make-up Solution) into the sample vessel and click on start. Q(0) is determined. 3.
8.6 Analyze Electroplating Bath Solutions 4. Place the Production bath solution into the sample vessel and measure Q. Operate a sequence in Electroplating Bath VA The sequence to measure with the electroplating modes CVS or CPVS includes the following steps: 1. Initial mixing time 2. Initial electrode conditioning a. Conditioning cycles (Number of “conditioning cycles” defined in No. of cycles on the Voltammetric tab of the EDIT WORKING METHOD PARAMETERS window) b. Pretreatment c.
8 How to ...? The “Addition mixing time” can be defined on the Determination tab of the EDIT WORKING METHOD PARAMETERS window. 6. Second Measurement: a. Conditioning cycles (Number of “conditioning cycles” defined in No. of cycles on the Voltammetric tab of the EDIT WORKING METHOD PARAMETERS window) b. Pretreatment c. Sweep (Number of sweeps is defined in No. of sweeps, number of saved sweeps in Save last ..
8.6 Analyze Electroplating Bath Solutions LAT parameters method number of samples LAT rack > Number of samples to be processed (entire sample rack) INIT sample > > ************1 ************0 > Initialize Remote lines First Sample on Pos.
8 How to ...? 1 2 28 27 3 29 30 31 58 59 87 57 56 84 86 85 112 55 83 111 Sample Rinsing solution not used ⇒ With 11 mL sample vessels: first sample on position 57, first rinsing solution on position 85. 1 2 28 27 3 30 31 59 87 58 29 57 56 84 86 85 112 55 83 111 Sample Rinsing solution not used Note: Before each start, define the position of the first sample vessel for the 838 parameter "SAMPLE" with the 838 keypad.
8.6 Analyze Electroplating Bath Solutions General Settings in the 797 Software Settings on the Dosinos tab of the GENERAL SETTINGS window in the 797 Software: It is recommended to do for all used Dosinos one "Prep cycle". On the Automation tab, select the 838 Advanced Sample Processor. The default settings can be adopted (click button ). Method Parameters for the 797 Set CVS or CPVS for Mode, and "MLAT" for Calibration.
8 How to ...? Dosino 2 is used to add Brightener standard solution. That should also be indicated on the Substances tab of the EDIT WORKING METHOD PARAMETERS window (here with CVS): Sample table List the samples in turn on the Sample table, and connect them to the according method (note the method parameters described above): Start determination.
8.6 Analyze Electroplating Bath Solutions Instruments Install the 838 Advanced Sample Processor, a 800 Dosino, a 732 Relay Box with two 823 Membrane Pump Units (see Hardware Manual 797 and 838 Instructions for Use). Dosinos: (Dosino 1: Dosino 2: (Dosino 3: not used) 2 mL Exchange Unit Brightener standard solution not used) Method at 838 Before each start, define the position of the first sample vessel for the 838 parameter "SAMPLE" with the 838 keypad.
8 How to ...? 50 mL sample vessels can be placed on the two outer rings (11 mL sample vessels on the two inner rings). Arrangement: Place on the outer of the two rings alternately "Intercept solution" and sample solution, on the inner of the two rings the rinsing solution.
8.6 Analyze Electroplating Bath Solutions It is recommended to do one "Prep cycle". On the Automation tab, select the 838 Advanced Sample Processor. The default settings can be adopted (click button ). Method Parameters for the 797 It is recommended to record the "Intercept value" with the Calibration technique "LAT Record intercept value" (that way it is stored in a file and can be read out automatically during the sample determination).
8 How to ...? After the addition of the sample, Brightener standard solution is added via Dosino 2.
8.6 Analyze Electroplating Bath Solutions Note: To make sure that always the latest intercept file is taken for the calculation, the name of the intercept file defined for the parameter Intercept determination, must match with the parameter Sample identifier on the Determination tab with Calibration technique "LAT Record intercept value".
8 How to ...? Suppressor Analysis with 838 Advanced Sample Processor and DT Following installations and settings are recommended for the automated Suppressor determination with the 838 Advanced Sample Processor and the "dilution titration technique": Instruments Install the 838 Advanced Sample Processor, two 800 Dosinos and a 732 Relay Box with two 823 Membrane Pump Units (see Hardware Manual 797 and 838 Instructions for Use).
8.6 Analyze Electroplating Bath Solutions >final sequence 1 SCN:Rm: 2 MOVE 3 LIFT: *****1** 1 1 : : next work mm 4 CTL:Rm: ************1 5 CTL:Rm: ************0 > Scan line for incoming signal from CT797 > Move needle to sample > Place needle at working position > Set line: Needle immersed in rinsing sol. > Note: If (as in this example) all used Dosinos are connected to the 797, the originally listed commands 6 – 10 of the sample sequence must be deleted.
8 How to ...? Activate both options on the General tab of the GENERAL SETTINGS window, so that a recorded calibration curve replaces the old one automatically. Settings on the Dosinos tab of the GENERAL SETTINGS window in the 797 Software: It is recommended to do for Dosino1 one "Prep cycle" and for Dosino3 two "Prep cycles". On the Automation tab, select the 838 Advanced Sample Processor. The default settings can be adopted (click button ).
8.6 Analyze Electroplating Bath Solutions Checking Use for predose for Dosino 1, VMS is added to the measuring vessel before the sample transfer. Then Suppressor standard solution is added via Dosino 3. That should be specified on the Substances tab of the EDIT WORKING METHOD PARAMETERS window (here the window for CVS): Determination of the sample: Choose "DT Suppressors with calibration curve" for Calibration technique.
8 How to ...
8.6 Analyze Electroplating Bath Solutions Note: To make sure that always the latest calibration file is taken for the calculation, the path of the calibration file defined for the parameter Calibration curve on the Determination tab (of the window EDIT WORKING METHOD PARAMETERS with calibration "DT Suppressors with calibration curve", must match with the path defined for the parameter Data folder (for the currently logged-in user) on the tab User Directories of the window USER RIGHTS.
8 How to ...? (Dosino 2: Dosino 3: not used) 2 mL Exchange Unit Sample / Suppressor standard solution Method at 838 Before each start, define the position of the first sample vessel for the 838 parameter "SAMPLE" with the 838 keypad. Set method LAT at the 838 Advanced Sample Processor. LAT parameters method number of samples LAT rack > Number of samples to be processed (entire sample rack) INIT sample > > ************1 ************0 > Initialize Remote lines First Sample on Pos.
8.6 Analyze Electroplating Bath Solutions Example for a sample rack with 12 samples: 1 2 28 27 3 29 30 31 59 87 58 57 56 84 86 85 112 55 83 111 Sample Rinsing solution not used Note: Although the first sample is placed on position 2, position 1 remains the starting position in the start sequence of the method at the 838 (recording the Response curve). Note: Before each start, define the position of the first sample vessel for the 838 parameter "SAMPLE" with the 838 keypad.
8 How to ...? Es wird für beide Dosino ein "Prep-Zyklus" empfohlen. On the Automation tab, select the 838 Advanced Sample Processor. The default settings can be adopted (click button ). Method Parameters for the 797 Two steps are required for Suppressor determination. One to record the response curve with Calibration technique "RC Record response curve", another for the actual sample determination with Calibration technique "RC Sample with response curve".
8.6 Analyze Electroplating Bath Solutions Determination of the sample: Choose "RC Sample with response curve" for Calibration technique. Settings in the DOSINOS window: Checking Use for predose for Dosino 1, Electrolyte solution is placed into the measuring vessel. Then, the measuring vessel is emptied (only if Add production bath to electrolyte on the tab Determination of the window for CVS is not activated) and the sample is placed.
8 How to ...? Note: To make sure that always the latest "response curve file" is taken for the calculation, the name of the "response curve file" defined for the parameter Response curve on the Determination tab (of the window EDIT WORKING METHOD PARAMETERS) with calibration "RC Sample with response curve", must match with the name defined for the parameter Sample identifier on the Determination tab (of the window EDIT WORKING METHOD PARAMETERS) with Calibration technique "RC Record response curve".
8.7 Standard addition technique Start determination. 8.7 Standard addition technique Use manual standard addition without solution exchange In the manual standard addition without solution exchange, a known amount of the analyte is added once or several times to the sample using a pipette. Proceed as follows: 1. Click on or MAIN WINDOW / Mode / Determination. 2. Click on or MAIN WINDOW / Window / Working method specification to open the WORKING METHOD SPECIFICATIONS window. 3.
8 How to ...? gle or mixed standard addition solution, its concentration and its volume is defined. 10. If the standard addition should be done with variable addition volumes, click the button in the Volume column to open the EDIT VARIED ADDITION window, enter the variable addition volumes in the Addition fields, and close this window by clicking . 11. Close the EDIT WORKING METHOD PARAMETERS window by clicking . 12. Place the sample solution in the measuring vessel at the 797 VA Computrace stand.
8.7 Standard addition technique 8. Select the Determination tab (see section 5.2) and enter Sample identifier, Sample amount, Cell volume, and the number of spiked solutions in the No. of cells field. 9. Select the Substances tab (see section 5.2) and make sure that for each substance entered in the table the concentrations of the spiked sample solutions are defined in the CELL CONCENTRATIONS window which is opened by clicking on the button. 10.
8 How to ...? 8. Check the Dosing Devices, which are used for standard addition in the Use field (see Dosing Devices, section 5.2) 9. Close the DOSINOS window by clicking . 10. Click to open the EDIT WORKING METHOD PA- RAMETERS window. 11. Select the Determination tab (see section 5.2) and enter Sample identifier, Sample amount, Cell volume, and the number of standard additions in the No. of additions field (If you work with the CVS or CPVS mode, see section 6.
8.8 Calibration curve technique 2. Click on or MAIN WINDOW / Window / Working method specification to open the WORKING METHOD SPECIFICATIONS window. 3. Load the desired method into the WORKING METHOD SPECIFICATIONS window (see How to Load a method, section 8.4). 4. Select Record calibration curve in the Calibration field of the WORKING METHOD SPECIFICATIONS window (is not selectable with the CVS and CPVS mode). 5. Select Manual in the Addition field of the WORKING METHOD SPECIFICATIONS window. 6.
8 How to ...? 1. Click on or MAIN WINDOW / Mode / Determination. 2. Click on or MAIN WINDOW / Window / Working method specification to open the WORKING METHOD SPECIFICATIONS window. 3. Load the desired method into the WORKING METHOD SPECIFICATIONS window (see How to Load a method, section 8.4). 4. Select Record calibration curve in the Calibration field of the WORKING METHOD SPECIFICATIONS window (Is not selectable with the CVS and CPVS mode). 5.
8.8 Calibration curve technique tion to the measuring solution using 700/800 Dosinos or 685/800 Dosimats. Proceed as follows: 1. Install Dosing Devices to the 797 VA Computrace stand (see How to Install Dosing Devices for automatic addition, section 8.1). 2. Click on or MAIN WINDOW / Mode / Determination. 3. Click on or MAIN WINDOW / Window / Working method specification to open the WORKING METHOD SPECIFICATIONS window. 4.
8 How to ...? Measure a sample using a calibration curve For the determination of a sample using a previously recorded calibration curve, this calibration curve must have been recorded and saved. Proceed as follows: 1. Click on or MAIN WINDOW / Mode / Determination. 2. Click on or MAIN WINDOW / Window / Working method specification to open the WORKING METHOD SPECIFICATIONS window. 3. Load the desired method into the WORKING METHOD SPECIFICATIONS window (see How to Load a method, section 8.4). 4.
8.10 Diagnostic procedures c(Hg(II)) = 1 g/L to the empty measuring vessel at the 797 VA Computrace stand. 3. Click on MAIN WINDOW / Utility / Film deposition to open the FILM DEPOSITION window. 4. Enter suitable parameters in the parameter list. 5. Click on the button. 6. Check the resulting test voltammogram. The voltammogram should show low noise and a low background current (low μA range). No interfering peaks should be visible.
8 How to ...? Check the stirring 1. Click on or MAIN WINDOW / Utility / Computrace control to open the COMPUTRACE CONTROL window. 2. Select HMDE and click on . 3. Change the rotational speed by clicking on the the RDE/stirrer speed field. buttons of Check the MME 1. Install the MME at the 797 VA Computrace stand (see Hardware Manual). 2. Click on or MAIN WINDOW / Utility / Computrace control to open the COMPUTRACE CONTROL window. 3. Select DME, SMDE or HMDE and click on . 4.
8.10 Diagnostic procedures 4. Select the method file Test797_L.mth in the OPEN window and click . The method is loaded into the WORKING METHOD SPECIFICATIONS window. 5. Connect the dummy cell at the 797 VA Computrace stand: Attach electrode cable AE to clamping screw AE, attach electrode cable RE to clamping screw RE, attach electrode cable WE to clamping screw WE-L. 6. Click on or MAIN WINDOW / Window / Monitor to open the MONITOR window. 7.
8 How to ...? 8. Enter the Sample ID (used as part of the determination file name) in the PLACE SAMPLE window and click . 9. At the end of the measurement, a curve is printed out. This curve should satisfy the following conditions: • A symmetrical, gaussian-shaped peak should be plotted. The evaluation must provide a result for the peak voltage and the peak current, which are printed out in the full report. • The peak voltage E should be -450 … -550 mV.
9.1 General procedure for error messages 9 Troubleshooting 9.1 General procedure for error messages Error messages and warnings are displayed in the CT797 window. Read the information about the possible causes and the procedure for their rectification and click the button. 9.2 Connection problems Error message "Could not start the embedded system" If this error message appears after starting the VA Computrace program, the USB connection has not established. Possible solutions: 1.
9 Troubleshooting Error message "Please select a new database file" If you work with the new program version «797 VA Computrace Software 1.3.x» and try to export to a database created with an old program version «797 VA Computrace Software 1.X», following error message appears. "The selected database file was created with a previous version of CT797. The data cannot be written to this database. Please select a new database file". Reason for this error is that the file structure of the Version w1.3.
9.5 General rules for VA trace analysis 4. Check the Dose rate parameter on the Dosinos tab. The default dosing rate for use of the 6.1824.000 4-way microtip is 2 mL/min. 9.5 General rules for VA trace analysis Chemicals and equipment 1. The purity of the reagents plays an important role in determining the results. Extremely pure chemicals should be used for determining lower concentrations (see VA Application Note V-49). 2.
9 Troubleshooting Samples 1. The amount of sample depends on the concentration of the element to be determined. 2. If the sample matrix is known, a better assessment of the analysis can be made (organic components?). 3. A digestion must be carried out on contaminated samples and on samples where contamination is suspected (see Metrohm Monograph «Sample preparation for techniques in voltammetric trace analysis»). 4. A lot of errors are made during sampling and when storing the sample.
9.5 General rules for VA trace analysis 1. DP (Differential Pulse) should always be the first choice. It is the most universal and frequently used voltammetric determination method and is equally well suited for reversible and irreversible systems. It offers a high sensitivity down to 10–8 mol/L and a separation ability of 1:50'000. 2. DC (Direct Current) is the classic, simplest VA method with limited sensitivity (down to 10-5 mol/L) and a separation ability of only 1:10.
9 Troubleshooting 11. CPVS (Cyclic Pulse Voltammetric Stripping) is mainly used for the determination of organic additives in electroplating electrolytes. CPVS is a chronoamperometric mode, current is measured against time. 9.6 Voltammetric problems Low background current or unstable baseline With all types of electrodes: 1. Check electrolyte concentration and pH of the solution. 2. Check Start potential and End potential of the sweep. 3.
9.6 Voltammetric problems 3. Exchange the RDE. 4. Has the electrode been conditioned (e.g. by using Conditioning cycles and Cleaning potential) ? 5. If the concentration to be determined is considerably higher than expected: reduce sample volume. 6. The background current is normally higher if RDE is used in place of MME; a background current of several 100 nA is possible. Curves with high noise Did you work in the SqW mode (if yes, see SqW Problems, section 9.6)? If not: With all MME types: 1.
9 Troubleshooting Example: (For all measurements: Amplitude: 0.02 V , Frequency: 50 Hz) Highest current range: Lowest current range: 180n 10 nA 10 nA Zn/Cd/Pb/Cu-Determination/DIN-Puffer/SqW Test Si_kap_nullserie Cd 160n Cu Pb I (A) Zn 140n 120n -1.00 -0.80 -0.60 -0.40 -0.20 0.00 U (V) 1 μA 1 μA Highest current range: Lowest current range: Zn/Cd/Pb/Cu-Determination/DIN-Puffer/SqW Test Si_kap_nullserie 120n Zn 100n I (A) 80.0n Cd 60.0n Cu Pb 40.0n 20.0n 0 -1.00 -0.80 -0.60 -0.
9.6 Voltammetric problems 2. Check and test the pipetting process: Pipetting the standard solutions must be carried out by one and the same person or with the same instrument or the same pipette. Was the pipetting unit used properly? When were the pipettes last calibrated (GLP)? 3. Organic components interfere with the analysis: carry out a UV digestion or other suitable sample preparation. 4. Are the calibration solutions too old? 5. Would a calibration curve be more suitable? With MME: 1.
9 Troubleshooting 5. Are organic components present? Carry out a UV digestion or other suitable sample preparation. With DME/SMDE: 1. The concentration of the ion to be determined is too low: use HMDE (stripping voltammetry) instead of DME or SMDE. With HMDE: 1. Has the complexing agent been forgotten? (adsorptive stripping voltammetry). 2. The Deposition time in the inverse voltammetry is too short: increase the time on the Voltammetric tab of the EDIT WORKING METHOD PARAMETERS window. 3.
9.6 Voltammetric problems 3. If a second element is present at the same potential: add this element to the sample and carry out the analysis again. If the second peak has become higher then the second element is present. Might it be possible to selectively mask this second element with a complexing agent? 4. For Cu: work without chlorides in the electrolyte or increase the chloride concentration massively. 5. Has any substance formed a precipitate in the measuring vessel (e.g.
9 Troubleshooting 2. If organic components are present: carry out a UV digestion or other suitable sample preparation. 3. Concentration of the analyte is too high: dilute. 4. Electrolyte solution too old: make up a new one. Its working life with organic additives may be as short as 1 day or less. With HMDE: 1. Standard addition solution containing metal complexing agents need time to form the metal complex. Spikes / signal jump in voltammogram 1. For MME: check the electrode. 2.
9.6 Voltammetric problems After Purging (oxygen removed from solution): Unsuitable bridging electrolyte in the reference electrode When choosing the bridging electrolyte in the reference electrode, possible complications with the substances present in the analysis solution must be taken into account.
9 Troubleshooting deposition even with concentrations ρ > 100 μg/L (e.g. DP voltammetry at the HMDE or also at the DME).
9.6 Voltammetric problems Hg Hg Analysis solution: Supporting electrolyte: Standard addition: Electrode: 100 μg/L Hg HClO4/HCl with 1 μg Hg Au-RDE Disturbances at the HMDE through gas formation Gas formation at the HMDE during the deposition phase can lead to drop fall or to a contact break in the Hg capillary.
9 Troubleshooting Analysis solution: Standard addition: Electrode: deionised water with 50 ng Zn HMDE (enrichment 60 s at –1.2 V) Complex formation Substances determined polarographically can occur in various complexed forms, depending on the composition of the analysis solution. As complexing is always associated with a shift in the halfwave potential and the limiting current, difficulties can arise in the peak evaluation.
9.6 Voltammetric problems 2– CuCl4 – CuCl2 Analysis solution: Standard addition: Electrode: CuEDTA 25 μg/L Cu; 10 μL HCl 30% with 250 ng Cu HMDE (enrichment 90 s at –600 mV) Peak on highly curved baseline If peaks lie on a highly curved baseline, the first attempts at rectification should involve chemical or measurement technique countermeasures to eliminate the adverse effect on the peak evaluation due to the highly curved baseline.
9 Troubleshooting If the overlapping is too large, the peak can no longer be evaluated. In this case chemical or measurement technique countermeasures must be used to attempt to separate these peaks better. Possible measures include changing the pH value, changing the supporting electrolyte concentration, changing the supporting electrolyte, use of complexing agents (see Complex formation, section 9.6), longer deposition times and modifying or changing the measurement technique.
9.6 Voltammetric problems To get reproducible results, the following points have to be considered: • Avoid strong temperature fluctuations in the laboratory. • Do not place the instrument directly below an air conditioning outlet. • If required, use a thermostatic measuring cell with connection to a thermostat/cryostat.
Software license Software license The use of the Software is subject to this License Agreement between you and Metrohm AG. With the offer, you have received this License Agreement and taken note of it. You have already accepted this License Agreement upon the placement of your order with Metrohm AG or one of its distributors or upon confirmation of the order by Metrohm or one of its distributors.
Software license 6. This Agreement applies until it is terminated. You can terminate this Agreement by destroying the Software and every copy of it. The Agreement is also deemed terminated if you violate any of its terms, in which case you are also obligated to destroy the Software and every copy of it, whereby Metrohm is also entitled to explicitly demand this of you. 7. Any changes and amendments to this Agreement must be rendered in writing to attain validity.
Declaration of conformity – Software validation Declaration of conformity – Software validation The software "797 VA Computrace" was developed in accordance with the requirements of the ISO 9001 quality system regarding the design, testing and servicing of Metrodata software. The relevant procedures are described in the document "Project procedure for creating Metrodata software" which is available at your Metrohm agency on request.
Index Index 8 838 Advanced Sample Processor method for trace analysis ........... 216 Operating sequence for Brightener Analysis with .............................. 224 Operating sequence for Brightener Analysis with LAT ....................... 228 Operating sequence for Suppressor Analysis.............................. 234, 239 Perform determinations.............. 215 863 Compact VA Autosampler Perform determinations.............. 214 A Absolute substance amount ........... 131 AC........................
Index Mode selection .............................16 Monitor ......................................110 Perform determination ...............212 Printing.......................................218 Printing of method parameters ...137 Recalculation ..............................217 Save determination.......12, 118, 212 Save determination as ..12, 118, 212 Specifications tab........................121 Start ...........................................109 Stop............................................
Index L Label style ........................................ 66 LAT Determination tab...................... 158 Substances tab........................... 161 Voltammetric tab ....................... 160 LAT Record intercept value............. 154 Determination tab...................... 155 Substances tab........................... 157 Voltammetric tab ....................... 156 LAT Standard addition for brighteners ...................................................... 158 Line............................
Index Reverse sweep............................79, 97 Rotating disk electrode .....................39 S Sample General rules ..............................260 Sample amount ....91, 111, 130, 135, 143 Sample curve properties..............127 Sample data ...............................130 Sample identifier...91, 111, 112, 114, 116 Sample measurement with calibration curve ..........................................252 Sample unit ................................135 sample bath solution ..............
Index 797 VA Computrace – Software 283
