HI 410 AMMO NIA 1 Instruction Manual HI 4101 Ammonia Ion Selective Electrode 1
HI 4101 Ammonia Electrode I. Introduction: The Hanna HI 4101 Ammonia gas selective electrode is a combination electrode designed for the measurement of ammonia in aqueous solutions such as waste water samples, wine, beer. Ammonium ions are also measured by conversion to ammonia gas upon ISA addition. II. Specifications Type: NH3 gas sensing electrode with glass pH internal, Ag/ AgCl reference and gas permeable PTFE membrane. NH4+, NH3 Species Measured: -6 Measurement Range: 1.0 M to 1x 10 M 17000 to 0.
III. Theory of Operation Operation:: The ammonia electrode is a complete potentiometric cell that contains both a silver/silver chloride (Ag/AgCl) reference and a pH measurement element. These elements are housed within a thermoplastic body in a chloride ion-containing electrolyte, and are isolated from the sample by a gas permeable membrane made of polytetrafluoroethylene (PTFE).
IV. Design Elements The Hanna HI 4101 ammonia gas sensor has 3 main parts. These are the membrane/membrane cap, outer probe body with antirotation key and the pH/reference assembly which includes the outer electrode cap, spring, inner cap and pH/reference electrode assembly.
V. Equipment Required: • Hanna HI 4222 pH/ISE/mV meter or other suitable ion or pH/mV meter. (Note: log/linear graph paper is useful if an ISE meter is not available). • Hanna HI 180 magnetic stirrer or equivalent with stirring bars. (Note: Isolate beakers from stirrer motor heat by placing insulating material such as foam or cork between them).
ions are capable of reducing the ammonia concentration. If other volumes of sample/standard are used, add ISA at 2 parts per 100 parts standard/sample. VII VII. General Guidelines • Calibration standards and sample solutions should have the same ionic strength. ISA should be added to both samples and standards immediately before taking measurements. • Calibration standards and sample solutions should be at the same temperature.
VIII. Inner Electrode Check Before assembling the electrode for the first time or if reactivating it after storage, the inner electrode assembly should be conditioned and then tested as a pH electrode. Prepare pH test solutions HI 4000-47-4 and HI 4000-477 by mixing and dissolving each buffer packet in separate containers with 50 mL deionized water. These pH solutions contain chloride ions and pH buffers that are used to verify the inner electrode (pH internal) is operational.
• If sensor has been stored or shipped dry, it should be “conditioned” by soaking the pH/reference assembly 1 hour or more in one of the pH test solutions. • Avoid touching the pH glass with your fingers. • Attention: The pH/reference assembly is fragile! Support the upper portion of the internal cell while immersing the glass and reference assembly. A tall narrow container with weighted bottom is best. The pH test solution should cover the bottom of the large black ban.
3) Hold one corner against the threads with thumb while gently stretching membrane over opening and capturing opposite membrane corner against threads . Smooth excess membrane material around the threads. 4) Screw outer membrane cap onto body thus capturing the membrane between the cap and outer body threads.
5.) Using dropper provided, add about 2 mL of ammonia internal electrolyte HI 4001-40 into outer probe body. 6) Insert and position the inner glass/reference assembly into the outer body so that the anti-rotation key sits in the cut out on the outer probe body. AMMONIA HI 4101 AMMONIA HI 4101 7) Holding the electrode upright, slide spring and electrode cap down cable and screw cap on outer body until fully engaged. Do not invert electrode. Do not overtighten.
X. Quick Check of Electrode Slope • Connect BNC (connector) to pH/mV/ISE meter. • Place meter in mV mode. • Place 100 mL of deionized water into a vessel with stir bar. Add 2 mL of ISA Hanna HI 4001-00. • Place sensor into prepared sample. • Add 1 mL of 1000 ppm or 0.1 M Ammonia standard to beaker. Record the mV value when stable. • Add an additional 10 mL of standard to the solution. Record the mV when reading has stabilized. This value should be less than the previous noted (more negative).
XII. Sample Handling • Keep samples stored in tightly covered bottles to prevent ammonia loss or ammonia contamination from other sources. • Alkaline samples must be measured at once or acidified for storage. (HCl may be added to bring pH to 6). • Acidic samples such as wine or juice may require addition ISA. Samples should be approximately pH 11 for measurement. • Measure sample and standards quickly after adding ISA because ammonia gas will escape from the solution.
XIII. Direct Calibration and Measurement The direct method can be used in the linear working regions of the sensor. (See figure for typical sensor response). A direct reading ISE meter (HI 4222 or equivalent) determines concentration of the unknown by a direct reading after calibrating the meter with the standards. The meter is calibrated with two or more freshly made standards that are in the measurement range of the unknowns. HI 400100 ISA is added just before measurement of the standard or sample.
• Standards should bracket the measurement range of interest and differ from each other by a factor of 10 in the linear regions. Standards and solutions should be at the same temperature. 2 mL of ISA is added to each 100 mL of sample and standard. A color change should occur to indicate the ISA has been added. Protect these solutions from loss of dissolved gas by covering and using promptly. Follow section VII; General Guidelines to optimize test set-up.
XIV echniques XIV.. Other Measurement TTechniques Known addition An unknown concentration of ammonia can be determined by adding a known amount (volume and concentration) of ammonia standard to a known volume of the sample. This technique is extremely useful for ammonia as the sensor may drift from calibrated values over time, however the slopes remain constant. With known addition, the standard and sample are measured within minutes of one another.
7) The procedure can be repeated with a second standard addition to verify slope and operation of the method. Note: This method is preprogrammed in the Hanna HI 4222pH/ISE/mV meter, which simplifies the method greatly and permits repeated determinations easily. Example: Ammonia determination with known addition: 1. A 50 mL sample of unknown (VSAMPLE) is placed in an clean vessel with an electrode. 1 mL of ISA is added to the sample and the color change is noted. The sample is covered and permitted to mix.
XV. Storage and Care of the HI 4101 sensor The HI 4101 sensor can be stored assembled and ready to use in HI 4001-45 Conditioning solution overnight or between measurements. After overnight storage, gently pull on the cable to compress the spring mechanism thus permitting electrolyte to exchange from the bulk to the thin film between the membrane and glass. Calibration is required after doing this.
XVII. HI 4101 AAccessories ccessories and Replacement PParts arts For Calibration : Code HI 4001-00 Ionic Strength Adjuster (500 mL) HI 4001-01 Hanna 0.1 M standard (500 mL) HI 4001-02* Hanna 100 ppm N standard (500 mL) Hanna 1000 ppm N standard (500mL) Nitrate test kit (Bulk pkg) HI 4001-03* HI 4001-30 *Please Note: These calibration standards are ppm as NH3-N.
MAN4101 10/08 R5 WARRANTY Hanna Instruments Ion Selective Electrodes are warranted to be free of defects in material and workmanship for 6 months from date of purchase when used for their intended purpose and maintained according to instructions. If they fail to work when first used contact your dealer immediately. Damage due to accidents, misuse, misapplication, tampering or lack of prescribed maintenance is not covered.
HI 410 AMMO NIA 1 Instruction Manual HI 4101 Ammonia Ion Selective Electrode 1
2
HI 4101 Ammonia Electrode I. Introduction: The Hanna HI 4101 Ammonia gas selective electrode is a combination electrode designed for the measurement of ammonia in aqueous solutions such as waste water samples, wine, beer. Ammonium ions are also measured by conversion to ammonia gas upon ISA addition. II. Specifications Type: NH3 gas sensing electrode with glass pH internal, Ag/ AgCl reference and gas permeable PTFE membrane. NH4+, NH3 Species Measured: -6 Measurement Range: 1.0 M to 1x 10 M 17000 to 0.
III. Theory of Operation Operation:: The ammonia electrode is a complete potentiometric cell that contains both a silver/silver chloride (Ag/AgCl) reference and a pH measurement element. These elements are housed within a thermoplastic body in a chloride ion-containing electrolyte, and are isolated from the sample by a gas permeable membrane made of polytetrafluoroethylene (PTFE).
IV. Design Elements The Hanna HI 4101 ammonia gas sensor has 3 main parts. These are the membrane/membrane cap, outer probe body with antirotation key and the pH/reference assembly which includes the outer electrode cap, spring, inner cap and pH/reference electrode assembly.
V. Equipment Required: • Hanna HI 4222 pH/ISE/mV meter or other suitable ion or pH/mV meter. (Note: log/linear graph paper is useful if an ISE meter is not available). • Hanna HI 180 magnetic stirrer or equivalent with stirring bars. (Note: Isolate beakers from stirrer motor heat by placing insulating material such as foam or cork between them).
ions are capable of reducing the ammonia concentration. If other volumes of sample/standard are used, add ISA at 2 parts per 100 parts standard/sample. VII VII. General Guidelines • Calibration standards and sample solutions should have the same ionic strength. ISA should be added to both samples and standards immediately before taking measurements. • Calibration standards and sample solutions should be at the same temperature.
VIII. Inner Electrode Check Before assembling the electrode for the first time or if reactivating it after storage, the inner electrode assembly should be conditioned and then tested as a pH electrode. Prepare pH test solutions HI 4000-47-4 and HI 4000-477 by mixing and dissolving each buffer packet in separate containers with 50 mL deionized water. These pH solutions contain chloride ions and pH buffers that are used to verify the inner electrode (pH internal) is operational.
• If sensor has been stored or shipped dry, it should be “conditioned” by soaking the pH/reference assembly 1 hour or more in one of the pH test solutions. • Avoid touching the pH glass with your fingers. • Attention: The pH/reference assembly is fragile! Support the upper portion of the internal cell while immersing the glass and reference assembly. A tall narrow container with weighted bottom is best. The pH test solution should cover the bottom of the large black ban.
3) Hold one corner against the threads with thumb while gently stretching membrane over opening and capturing opposite membrane corner against threads . Smooth excess membrane material around the threads. 4) Screw outer membrane cap onto body thus capturing the membrane between the cap and outer body threads.
5.) Using dropper provided, add about 2 mL of ammonia internal electrolyte HI 4001-40 into outer probe body. 6) Insert and position the inner glass/reference assembly into the outer body so that the anti-rotation key sits in the cut out on the outer probe body. AMMONIA HI 4101 AMMONIA HI 4101 7) Holding the electrode upright, slide spring and electrode cap down cable and screw cap on outer body until fully engaged. Do not invert electrode. Do not overtighten.
X. Quick Check of Electrode Slope • Connect BNC (connector) to pH/mV/ISE meter. • Place meter in mV mode. • Place 100 mL of deionized water into a vessel with stir bar. Add 2 mL of ISA Hanna HI 4001-00. • Place sensor into prepared sample. • Add 1 mL of 1000 ppm or 0.1 M Ammonia standard to beaker. Record the mV value when stable. • Add an additional 10 mL of standard to the solution. Record the mV when reading has stabilized. This value should be less than the previous noted (more negative).
XII. Sample Handling • Keep samples stored in tightly covered bottles to prevent ammonia loss or ammonia contamination from other sources. • Alkaline samples must be measured at once or acidified for storage. (HCl may be added to bring pH to 6). • Acidic samples such as wine or juice may require addition ISA. Samples should be approximately pH 11 for measurement. • Measure sample and standards quickly after adding ISA because ammonia gas will escape from the solution.
XIII. Direct Calibration and Measurement The direct method can be used in the linear working regions of the sensor. (See figure for typical sensor response). A direct reading ISE meter (HI 4222 or equivalent) determines concentration of the unknown by a direct reading after calibrating the meter with the standards. The meter is calibrated with two or more freshly made standards that are in the measurement range of the unknowns. HI 400100 ISA is added just before measurement of the standard or sample.
• Standards should bracket the measurement range of interest and differ from each other by a factor of 10 in the linear regions. Standards and solutions should be at the same temperature. 2 mL of ISA is added to each 100 mL of sample and standard. A color change should occur to indicate the ISA has been added. Protect these solutions from loss of dissolved gas by covering and using promptly. Follow section VII; General Guidelines to optimize test set-up.
XIV echniques XIV.. Other Measurement TTechniques Known addition An unknown concentration of ammonia can be determined by adding a known amount (volume and concentration) of ammonia standard to a known volume of the sample. This technique is extremely useful for ammonia as the sensor may drift from calibrated values over time, however the slopes remain constant. With known addition, the standard and sample are measured within minutes of one another.
7) The procedure can be repeated with a second standard addition to verify slope and operation of the method. Note: This method is preprogrammed in the Hanna HI 4222pH/ISE/mV meter, which simplifies the method greatly and permits repeated determinations easily. Example: Ammonia determination with known addition: 1. A 50 mL sample of unknown (VSAMPLE) is placed in an clean vessel with an electrode. 1 mL of ISA is added to the sample and the color change is noted. The sample is covered and permitted to mix.
XV. Storage and Care of the HI 4101 sensor The HI 4101 sensor can be stored assembled and ready to use in HI 4001-45 Conditioning solution overnight or between measurements. After overnight storage, gently pull on the cable to compress the spring mechanism thus permitting electrolyte to exchange from the bulk to the thin film between the membrane and glass. Calibration is required after doing this.
XVII. HI 4101 AAccessories ccessories and Replacement PParts arts For Calibration : Code HI 4001-00 Ionic Strength Adjuster (500 mL) HI 4001-01 Hanna 0.1 M standard (500 mL) HI 4001-02* Hanna 100 ppm N standard (500 mL) Hanna 1000 ppm N standard (500mL) Nitrate test kit (Bulk pkg) HI 4001-03* HI 4001-30 *Please Note: These calibration standards are ppm as NH3-N.
MAN4101 10/08 R5 WARRANTY Hanna Instruments Ion Selective Electrodes are warranted to be free of defects in material and workmanship for 6 months from date of purchase when used for their intended purpose and maintained according to instructions. If they fail to work when first used contact your dealer immediately. Damage due to accidents, misuse, misapplication, tampering or lack of prescribed maintenance is not covered.
