Instruction Manual

8.5 Determinations with voltammetric trace analysis
797 VA Computrace – Software
213
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.
2. Click on or MAIN WINDOW / Window / Working method
specification
to open the WORKING METHOD SPECIFICATIONS
window.
3. Click on or MAIN WINDOW / File / Load method.
4. Select the method file Test Pb in standard solution.mth in the
OPEN window and click <OK>. The method is loaded into the
WORKING METHOD SPECIFICATIONS window.
5. Add 20 mL ultrapure water to the empty measuring vessel at
the 797 VA Computrace stand.
6. Add 0.5 mL potassium chloride c(KCl) = 3 mol/L (Metrohm No.
6.2308.020) to the measuring vessel.
7. Click on or MAIN WINDOW / Window / Monitor to open
the MONITOR window.
8. Start the measurement by clicking the icon in the MAIN
WINDOW
or the button in the MONITORING win-
dow. The PLACE SAMPLE window appears.
9. Use a pipette to add 100 μL Pb ion standard solution β(Pb) = 1
g/L (Metrohm No. 6.2301.100) into the measuring vessel and
click the
<OK> button.
10. The sample solution is measured three times. Then the MAN-
UAL ADDITION
window appears.
11. Use a pipette to add 100 μL Pb ion standard solution β(Pb) = 1
g/L (Metrohm No. 6.2301.100) into the measuring vessel and
click the
<OK> button.
12. The sample solution spiked with standard addition solution is
measured three times. Then the MANUAL ADDITION window
appears.
13. Use a pipette to add 100 μL Pb ion standard solution β(Pb) = 1
g/L (Metrohm No. 6.2301.100) into the measuring vessel and
click the <OK> button.
14. The sample solution spiked again with standard addition solu-
tion is measured three times. Then the END OF DETERMINA-
TION
window appears.