GB/T 3914-1983 General rules for anodic stripping voltammetry with chemical reagents
Some standard content:
National Standard of the People's Republic of China
Chemical reagents
The general rules of anodic stripping voltammetryUDC 543.253
.063:54-4
GB 3914—83
This method is applicable to the determination of metal ion impurities in common chemical reagents and high-purity chemical reagents, especially zinc, cadmium, lead and copper. The sensitivity can reach ppb level.
This method can continuously determine several impurities in one determination process. This general rule only stipulates the two-electrode system with silver-based mercury film electrode as working electrode and silver-silver chloride electrode as reference electrode and the three-electrode system with added counter electrode.
This general rule adopts linear displacement stripping method.
2 Nouns and terms
The definitions of the nouns and terms used in this standard are as follows: 2.1 Counter electrode
When using a three-electrode system, the cathode that carries a larger current during the dissolution process. 2.2 Supporting electrolyte solution
The solvent for dissolving the sample for anodic stripping voltammetry determination. 2.3 Pre-electrolysis potential and pre-electrolysis time
The voltage and time used to electrolyze and enrich the metal ions to be measured on the working electrode. 2.4 Scanning potential range
When making a dissolution determination, the potential range selected from negative to positive. 2.5 Scanning rate
When making a dissolution determination, the value of the potential change per unit time. 2.6 Linear displacement dissolution method
When making a dissolution determination, a method of linear displacement of the potential from negative to positive at a certain scanning rate is used. 2.7. Release potential and release time
After the dissolution determination, the dissolution voltage and dissolution time applied to remove the metal impurities remaining on the working electrode. 2.8 Intermetallic compounds
When the amount of two metals electrolytically reduced to the mercury electrode exceeds their solubility product in mercury, the excess will precipitate in the form of metal compounds. This type of metal compound is called an intermetallic compound. 3 Principle of the method
The impurities zinc, cadmium, lead, copper, etc. contained in the chemical reagent product can be reduced to the mercury film electrode in an appropriate supporting electrolyte solution with a mercury film electrode as the working electrode and a silver-silver chloride electrode as the reference electrode, and an appropriate pre-electrolysis potential. After a certain period of pre-electrolysis enrichment, they are reduced to the mercury film electrode and form amalgam with mercury. Then, a reverse dissolution scan is performed in a relatively short period of time, and its dissolution voltammetric curve is recorded. According to the peak potential and peak height of GB 3914-83 issued by the National Bureau of Dissolution Standards on November 7, 1983 and implemented on July 1, 1984, the content of each impurity is quantitatively determined by the standard addition method. The reaction formula is: M”+ne+Hg Pre-electrolysis enrichment M (Hg) dissolution
Where: M
metal;
valence of metal ion;
-electron,
Hg—mercury on mercury film electrode.
4 Instruments
4.1 Voltammeter
The voltammeter should meet the following requirements:
4.1.1 Conditions of use
Ambient temperature: 5～40℃;
Relative humidity: <80%,
Power supply: 220V±10%.
4.1.2 Instrument performance
Starting voltage: +2～～2V,
|Scanning amplitude: +2～－2V,
Scanning rate: more than four levels in the range of 10～100mV/s, sensitivity: more than five levels in the range of 10～0.25μA/mV Slope compensation: >10mV (measured at 1V); voltmeter scale: <0.1V;
Stability: the instrument is used continuously for 4h, and the voltmeter reading changes no more than 0.03V. 4.2 Electrodes
4.2.1J. As electrodes
, silver-based mercury film electrodes are used. The silver base of the electrode is cylindrical, 10~16mm long and about 2mm in diameter . The amount of mercury applied is 3 to 5 mg. 4.2.2 Reference electrode
Use silver-silver chloride electrode and 1M potassium chloride aqueous solution as salt bridge. 4.2.3 Counter electrode
Use platinum electrode or glassy carbon electrode.
4.3 Electrolytic cell
Use electrolytic cell made of quartz material or polystyrene or polyethylene material. 4.4 Recorder
Use function recorder or long chart recorder, and the full stroke time of the recording pen is 0.5 second or 1 second. 5 Reagents
5.1 Requirement: Use high-purity reagents.
5.2 Nitrogen: Use content 99.99% nitrogen. 5.3 Water: Use double distilled water or water that has been distilled after ion exchange. 5.4 Others: Reagents used for sample treatment such as extraction, separation, neutralization, etc. and reagents used in preparing supporting electrolyte solutions are reagents used in large quantities and should be high-purity reagents. Indicators, masking agents and other reagents used in small quantities should be of analytical grade or above. 5.5 Impurity standard: Prepared in accordance with GB602-77 "Preparation Method for Impurity Standard Solutions of Chemical Reagents", and diluted according to experimental requirements before use.
6 Determination
6.1 Determination Procedure
GB 3914—83
According to the provisions of the product technical standards, weigh a certain amount of sample (or after treatment according to the provisions of the product technical standards), and dissolve it in a certain volume of supporting electrolyte solution. Transfer this solution to a clean electrolytic cell, insert electrodes, pass nitrogen for an appropriate time, and then turn on the power supply. Pre-electrolyze and enrich for an appropriate time under the conditions of the specified pre-electrolysis potential and constant stirring. After stopping stirring for a certain period of time; perform dissolution scanning at an appropriate scanning rate within the specified scanning potential range, and record its dissolution voltammetric curve. After the dissolution scan, perform dissolution for an appropriate time under constant stirring and appropriate potential conditions. Then add a certain amount of impurity standard in proportion, and repeat the above procedure (starting from pre-electrolysis). The impurity standard should not be added less than three times. Perform blank determination at the same time.
6.2 Calculation
Use the standard addition method. That is, the amount of impurities added ml, m2, m3 (μg) is used as the horizontal axis, and the corresponding peak height (mm) is used as the vertical axis to draw a graph. The extrapolated intersection point m with the horizontal axis is the impurity content in the sample, as shown in the figure. Peak height (mm)
Amount of impurities added
The percentage of the measured impurity in the sample (X) is calculated according to formula (1): X=
Where: mx
G×106
The amount of impurities measured is extrapolated from the figure, μg, - sample weight, g.
(μg)
Because the volume of the electrolyte increases with the addition of impurity standard solution, the dissolution peak height should be corrected. The peak height (H correction) of the corrected dissolution peak is measured in millimeters and calculated according to formula (2);
V. +V
Hcalibration=H
Where: H measured dissolution peak height, mm,
~ original volume of electrolyte, ml;
- volume of impurity standard solution added, ml. 6.3 Selection of determination conditions
6.3.1 Sample treatment
When the sample is a soluble salt of alkali metal, alkaline earth metal, cobalt (II), nickel, zinc, etc., and it is desired to determine the impurities cadmium, lead, and copper contained therein, the sample can be directly dissolved in the selected supporting electrolyte solution for determination. When the sample is a volatile product, such as acetic anhydride, chloroform, benzene, hydrochloric acid, nitric acid, ammonia water, etc., it can be heated in a water bath to volatilize and remove the main body of the sample, and the impurities in the residue can be determined. Changing the valence of the main body can also create conditions for determination. For example, if you want to measure impurities in hypochlorite, you can first oxidize arsenic to high arsenic, and use the characteristic that high arsenic rarely undergoes electrochemical reactions to determine the impurities it contains. Precipitation, extraction, and the addition of masking agents are also commonly used methods to separate and remove interferences. Neutralizing the sample with acid or alkali to the pH value required for determination is necessary for most sample processing. 6.3.2 Preparation of supporting electrolyte solution
The following factors should be considered when preparing supporting electrolyte solution: 6.3.2.1 Adding strong electrolytes
Add strong electrolytes that do not interfere with the determination so that the concentration of strong electrolytes in the prepared solution is above 0.1m, which is conducive to conductivity. But it should not be too concentrated, which will affect the diffusion rate of metal ions. 6.3.2.2 Maintain a certain pH value
The supporting electrolyte solution should have a certain pH value according to the method requirements and a certain buffering capacity to ensure that the determination is carried out at a certain pH value. For example, when measuring zinc, lead, lead and copper at pH 8.5, a buffer solution made of ammonium acetate and ammonia water is used as the supporting electrolyte. When measuring cadmium, lead and copper under strong acidic conditions, the strong acid itself is the buffer. 6.3.2.3 Adding complexing agents
Adding complexing agents appropriately can eliminate interference or increase the selectivity of the method. 6.3.2.4 Adding reagents that can eliminate the interference of metal intermetallic compounds. Adding certain metal ions can eliminate the influence of metal intermetallic compounds on the accuracy of determination caused by the formation of metal intermetallic compounds by the measured substance. For example, adding trivalent gallium can eliminate the interference of metal intermetallic compounds formed by the measured substance zinc and copper, so as to ensure the accuracy of zinc determination. 6.3.3 Sample concentration
When directly determining impurities in the sample, the sample concentration should be lower than the concentration of strong electrolyte in the supporting electrolyte solution. For samples that need to be pre-treated, the concentration of the reagent used to treat the sample in the supporting electrolyte solution should be lower than the concentration of strong electrolyte in the supporting electrolyte solution. 6.3.4 Nitrogen flow time
Nitrogen should be flowed for more than 10 minutes at the beginning. During the determination, a nitrogen atmosphere should be maintained on the electrolyte. 6.3.5 Stirring
When electromagnetic stirring is selected, the speed should be not less than 600rpm [1rpm=（1/60）s-1]. The speed should be kept constant during the determination.
When gas stirring is selected, accurate and constant flow rate control should be provided. 6.3.6 Selection of pre-electrolysis potential
The following three factors should be considered in selecting the pre-electrolysis potential: 6.3.6.1 At the selected pre-electrolysis potential, hydrogen ions in the supporting electrolyte solution cannot be electrolyzed. For example, when 0.1N hydrochloric acid is used as the supporting electrolyte solution, the pre-electrolysis potential should be positive at -1.3V, and when a weak alkaline solution of ammonium acetate-ammonium is used as the supporting electrolyte solution, the pre-electrolysis potential should be positive at -1.7V.
6.3.6.2 At the selected pre-electrolysis potential, the sample itself cannot undergo an electrochemical reaction. 6.3.6.3 The selected pre-electrolysis potential should be more than 0.2V negative than the dissolution peak potential of the metal impurity to be measured under the measurement conditions. 6.3.7 Pre-electrolysis time
The pre-electrolysis time cannot be less than 1min and cannot be more than 10min. The pre-electrolysis time should be constant during the measurement process. The specific time depends on the concentration of the impurity to be measured, the sensitivity of the instrument, and the volume of the electrode. 6.3.8 Stirring stop time
\~ is generally 30s or 60s and cannot be extended. The selected stirring stop time should be consistent in each measurement process. 6.3.9 Scanning rate
Under the conditions specified in this general rule, the scanning rate is preferably 20~60mV/s. 132
GB 3914-83
In some cases, 10~100mV/s can be selected. For example, if the sensitivity of the impurity to be measured is to be improved, and the change of separation and capacitance current does not affect the measurement, a scanning rate greater than 60mV/s can be used, but not greater than 100mV/s. 6.3.10 Scanning potential range
The scanning potential range should include all dissolution peaks of all impurities to be measured. 6.3.11 Release potential and release time
The release potential is -0.05V or -0.1V, and the release time is 1min or 2min. The release potential and release time should be constant during the measurement.
6.3.12 The amount of impurities added each time
The amount of impurity standard added for the first time cannot be greater than the specification amount; the increase in the corresponding dissolution peak height caused by the electrochemical reaction of each impurity addition cannot be less than 8mm, and the total amount of impurities added three times must be greater than the specification amount. 7 Method error
7.1 Precision
When formulating the method, calculate the relative standard deviation (Sr) when the number of measurements is not less than eleven times. Sr<20% is required.
7.2 Recovery
The method recovery rate is required to be within the range of 80-120%. Safety precautions
8.1 When applying mercury, using and dissolving mercury on mercury film electrodes, be careful not to leave mercury in the laboratory. When using mercury film electrodes discontinuously, the mercury on the electrodes should be dissolved and removed before storage. The laboratory should have exhaust equipment.
The laboratory should regularly test the content of mercury in the air, which is required to be lower than the national standard, that is, less than 0.01mg/m3. Personnel who are engaged in this work for a long time should be subject to regular physical examination. 8.2 The use of high-pressure nitrogen cylinders should be carried out in accordance with the safety operation regulations of high-pressure cylinders. 133
Nouns and terms
Anodic stripping voltammetry
Mercury film electrode
Silver-based film electrode
Working electrode
Reference electrode
Counter electrode
GB 3914—83
Appendix A
Nouns, terms and symbols table
(Supplement)
anodic stripping voltammetrymercury film electrode
mercury film electrode on silver supportworking electrode
reference electrodeWww.bzxZ.net
counter electrode
deaerate
supporting electrolyte solution supporting electrolyte solution
electrolytic cell
pre - electrolysis potential
pre - electrolysis time
stop stirring time
potential scan range
scan rate
stripping peak potential
stripping peak current
standard addition method
impurities added
release potential
release time
intermetallic compound
1 interfering substance
detection limit
relative standard deviation
recovery rate
linear range
electrolytic cell
pre - electrolysis potentialpre - electrolysis time
stop stirring time
potential scan range
scan rate
stripping peak potential
stripping peak current
standard addition
impurity added
rest potential
rest period
intermetallic compound
interferent
detection limit
relative standard deviation
recovery percent
range of linear response
mV/s
nanogram/ml
percent
percent
unit symbol
synonyms
anodic dissolution method, etc.
electrolysis of blood, etc.
electrolysis potential
electrolysis time
intermetallic compound
detection limit
coefficient of variation
B.1 Instrument
GB 3914—83
Appendix B
Conditions to be given in product technical standards
(Supplement)
According to the provisions of Chapter 4 of GB391483 "General Rules for Extreme Stripping Voltammetry of Chemical Reagents". B.2 Chemical reagents
According to the provisions of Chapter 5 of GB3914--83.
B.3 Determination
B.3.1 Determination conditions
Pre-electrolysis potential V;
Scanning potential range V,
Dissolution peak potential,
B.3.2 Determination procedure
Required to give the sample amount (g), sample treatment method, supporting electrolyte solution composition and added volume (ml): other necessary conditions.
B.4 Calculation
According to the provisions of GB3914--836.2.
Additional Notes:
This standard was proposed by the Ministry of Chemical Industry of the People's Republic of China and is under the jurisdiction of Beijing Chemical Reagent General Factory. This standard was drafted by Beijing Chemical Reagent General Factory. The main drafter of this standard was Liu Tianzhao.3 Sample concentration
When directly measuring impurities in the sample, the sample concentration should be lower than the concentration of strong electrolyte in the supporting electrolyte solution. For samples that need to be pre-treated, the concentration of the reagent used to treat the sample in the supporting electrolyte solution should be lower than the concentration of strong electrolyte in the supporting electrolyte solution. 6.3.4 Nitrogen flow time
Nitrogen should be flowed for more than 10 minutes at the beginning. A nitrogen atmosphere should be maintained on the electrolyte during the measurement. 6.3.5 Stirring
When electromagnetic stirring is selected, the speed should be no less than 600rpm [1rpm=（1/60）s-1]. The speed should be kept constant during the measurement.
When gas stirring is selected, accurate and constant flow rate control should be provided. 6.3.6 Selection of pre-electrolysis potential
The following three factors should be considered in selecting the pre-electrolysis potential: 6.3.6.1 At the selected pre-electrolysis potential, the hydrogen ions in the supporting electrolyte solution cannot be electrolyzed. For example: when 0.1N hydrochloric acid is used as the supporting electrolyte solution, the pre-electrolysis potential should be positive at -1.3V; when a weak alkaline solution of ammonia-ammonium acetate is used as the supporting electrolyte solution, the pre-electrolysis potential should be positive at -1.7V.
6.3.6.2 At the selected pre-electrolysis potential, the sample itself cannot undergo an electrochemical reaction. 6.3.6.3 The selected pre-electrolysis potential should be more than 0.2V negative than the dissolution peak potential of the metal impurity to be measured under the measurement conditions. 6.3.7 Pre-electrolysis time
The pre-electrolysis time cannot be less than 1min and cannot be more than 10min. The pre-electrolysis time should be constant during the measurement process. The specific time depends on the concentration of the impurity to be measured, the sensitivity of the instrument, and the volume of the electrode. 6.3.8 Stop stirring time
\~ is generally 30s or 60s and cannot be extended. The selected stop stirring time should be consistent in each measurement process. 6.3.9 Scanning rate
Under the conditions specified in this general rule, the scanning rate is preferably 20 to 60 mV/s. 132
GB 3914-83
In some cases, 10 to 100 mV/s can be selected. For example, if the sensitivity of the impurity to be measured is to be increased, and the change of separation and capacitance current does not affect the measurement, a scanning rate greater than 60 mV/s can be used, but not greater than 100 mV/s. 6.3.10 Scanning potential range
The scanning potential range should include all dissolution peaks of all impurities to be measured. 6.3.11 Release potential and release time
The release potential is -0.05 V or -0.1 V, and the release time is 1 min or 2 min. The release potential and release time should be constant during the measurement.
6.3.12 The amount of impurities added each time
The amount of impurity standard added for the first time cannot be greater than the specification amount; the increase in the corresponding dissolution peak height caused by the electrochemical reaction of each impurity addition cannot be less than 8mm, and the total amount of impurities added three times must be greater than the specification amount. 7 Method error
7.1 Precision
When formulating the method, calculate the relative standard deviation (Sr) when the number of measurements is not less than eleven times. Sr<20% is required.
7.2 Recovery
The method recovery rate is required to be within the range of 80-120%. Safety precautions
8.1 When applying mercury, using and dissolving mercury on mercury film electrodes, be careful not to leave mercury in the laboratory. When using mercury film electrodes discontinuously, the mercury on the electrodes should be dissolved and removed before storage. The laboratory should have exhaust equipment.
The laboratory should regularly test the content of mercury in the air, which is required to be lower than the national standard, that is, less than 0.01mg/m3. Personnel who are engaged in this work for a long time should be subject to regular physical examination. 8.2 The use of high-pressure nitrogen cylinders should be carried out in accordance with the safety operation regulations of high-pressure cylinders. 133
Nouns and terms
Anodic stripping voltammetry
Mercury film electrode
Silver-based film electrode
Working electrode
Reference electrode
Counter electrode
GB 3914—83
Appendix A
Nouns, terms and symbols table
(Supplement)
anodic stripping voltammetrymercury film electrode
mercury film electrode on silver supportworking electrode
reference electrode
counter electrode
deaerate
supporting electrolyte solution supporting electrolyte solution
electrolytic cell
pre - electrolysis potential
pre - electrolysis time
stop stirring time
potential scan range
scan rate
stripping peak potential
stripping peak current
standard addition method
impurities added
release potential
release time
intermetallic compound
1 interfering substance
detection limit
relative standard deviation
recovery rate
linear range
electrolytic cell
pre - electrolysis potentialpre - electrolysis time
stop stirring time
potential scan range
scan rate
stripping peak potential
stripping peak current
standard addition
impurity added
rest potential
rest period
intermetallic compound
interferent
detection limit
relative standard deviation
recovery percent
range of linear response
mV/s
nanogram/ml
percent
percent
unit symbol
synonyms
anodic dissolution method, etc.
electrolysis of blood, etc.
electrolysis potential
electrolysis time
intermetallic compound
detection limit
coefficient of variation
B.1 Instrument
GB 3914—83
Appendix B
Conditions to be given in product technical standards
(Supplement)
According to the provisions of Chapter 4 of GB391483 "General Rules for Extreme Stripping Voltammetry of Chemical Reagents". B.2 Chemical reagents
According to the provisions of Chapter 5 of GB3914--83.
B.3 Determination
B.3.1 Determination conditions
Pre-electrolysis potential V;
Scanning potential range V,
Dissolution peak potential,
B.3.2 Determination procedure
Required to give the sample amount (g), sample treatment method, supporting electrolyte solution composition and added volume (ml): other necessary conditions.
B.4 Calculation
According to the provisions of GB3914--836.2.
Additional Notes:
This standard was proposed by the Ministry of Chemical Industry of the People's Republic of China and is under the jurisdiction of Beijing Chemical Reagent General Factory. This standard was drafted by Beijing Chemical Reagent General Factory. The main drafter of this standard was Liu Tianzhao.3 Sample concentration
When directly measuring impurities in the sample, the sample concentration should be lower than the concentration of strong electrolyte in the supporting electrolyte solution. For samples that need to be pre-treated, the concentration of the reagent used to treat the sample in the supporting electrolyte solution should be lower than the concentration of strong electrolyte in the supporting electrolyte solution. 6.3.4 Nitrogen flow time
Nitrogen should be flowed for more than 10 minutes at the beginning. A nitrogen atmosphere should be maintained on the electrolyte during the measurement. 6.3.5 Stirring
When electromagnetic stirring is selected, the speed should be no less than 600rpm [1rpm=（1/60）s-1]. The speed should be kept constant during the measurement.
When gas stirring is selected, accurate and constant flow rate control should be provided. 6.3.6 Selection of pre-electrolysis potential
The following three factors should be considered in selecting the pre-electrolysis potential: 6.3.6.1 At the selected pre-electrolysis potential, the hydrogen ions in the supporting electrolyte solution cannot be electrolyzed. For example: when 0.1N hydrochloric acid is used as the supporting electrolyte solution, the pre-electrolysis potential should be positive at -1.3V; when a weak alkaline solution of ammonia-ammonium acetate is used as the supporting electrolyte solution, the pre-electrolysis potential should be positive at -1.7V.
6.3.6.2 At the selected pre-electrolysis potential, the sample itself cannot undergo an electrochemical reaction. 6.3.6.3 The selected pre-electrolysis potential should be more than 0.2V negative than the dissolution peak potential of the metal impurity to be measured under the measurement conditions. 6.3.7 Pre-electrolysis time
The pre-electrolysis time cannot be less than 1min and cannot be more than 10min. The pre-electrolysis time should be constant during the measurement process. The specific time depends on the concentration of the impurity to be measured, the sensitivity of the instrument, and the volume of the electrode. 6.3.8 Stop stirring time
\~ is generally 30s or 60s and cannot be extended. The selected stop stirring time should be consistent in each measurement process. 6.3.9 Scanning rate
Under the conditions specified in this general rule, the scanning rate is preferably 20 to 60 mV/s. 132
GB 3914-83
In some cases, 10 to 100 mV/s can be selected. For example, if the sensitivity of the impurity to be measured is to be increased, and the change of separation and capacitance current does not affect the measurement, a scanning rate greater than 60 mV/s can be used, but not greater than 100 mV/s. 6.3.10 Scanning potential range
The scanning potential range should include all dissolution peaks of all impurities to be measured. 6.3.11 Release potential and release time
The release potential is -0.05 V or -0.1 V, and the release time is 1 min or 2 min. The release potential and release time should be constant during the measurement.
6.3.12 The amount of impurities added each time
The amount of impurity standard added for the first time cannot be greater than the specification amount; the increase in the corresponding dissolution peak height caused by the electrochemical reaction of each impurity addition cannot be less than 8mm, and the total amount of impurities added three times must be greater than the specification amount. 7 Method error
7.1 Precision
When formulating the method, calculate the relative standard deviation (Sr) when the number of measurements is not less than eleven times. Sr<20% is required.
7.2 Recovery
The method recovery rate is required to be within the range of 80-120%. Safety precautions
8.1 When applying mercury, using and dissolving mercury on mercury film electrodes, be careful not to leave mercury in the laboratory. When using mercury film electrodes discontinuously, the mercury on the electrodes should be dissolved and removed before storage. The laboratory should have exhaust equipment.
The laboratory should regularly test the content of mercury in the air, which is required to be lower than the national standard, that is, less than 0.01mg/m3. Personnel who are engaged in this work for a long time should be subject to regular physical examination. 8.2 The use of high-pressure nitrogen cylinders should be carried out in accordance with the safety operation regulations of high-pressure cylinders. 133
Nouns and terms
Anodic stripping voltammetry
Mercury film electrode
Silver-based film electrode
Working electrode
Reference electrode
Counter electrode
GB 3914—83
Appendix A
Nouns, terms and symbols table
(Supplement)
anodic stripping voltammetrymercury film electrode
mercury film electrode on silver supportworking electrode
reference electrode
counter electrode
deaerate
supporting electrolyte solution supporting electrolyte solution
electrolytic cell
pre - electrolysis potential
pre - electrolysis time
stop stirring time
potential scan range
scan rate
stripping peak potential
stripping peak current
standard addition method
impurities added
release potential
release time
intermetallic compound
1 interfering substance
detection limit
relative standard deviation
recovery rate
linear range
electrolytic cell
pre - electrolysis potentialpre - electrolysis time
stop stirring time
potential scan range
scan rate
stripping peak potential
stripping peak current
standard addition
impurity added
rest potential
rest period
intermetallic compound
interferent
detection limit
relative standard deviation
recovery percent
range of linear response
mV/s
nanogram/ml
percent
percent
unit symbol
synonyms
anodic dissolution method, etc.
electrolysis of blood, etc.
electrolysis potential
electrolysis time
intermetallic compound
detection limit
coefficient of variation
B.1 Instrument
GB 3914—83
Appendix B
Conditions to be given in product technical standards
(Supplement)
According to the provisions of Chapter 4 of GB391483 "General Rules for Extreme Stripping Voltammetry of Chemical Reagents". B.2 Chemical reagents
According to the provisions of Chapter 5 of GB3914--83.
B.3 Determination
B.3.1 Determination conditions
Pre-electrolysis potential V;
Scanning potential range V,
Dissolution peak potential,
B.3.2 Determination procedure
Required to give the sample amount (g), sample treatment method, supporting electrolyte solution composition and added volume (ml): other necessary conditions.
B.4 Calculation
According to the provisions of GB3914--836.2.
Additional Notes:
This standard was proposed by the Ministry of Chemical Industry of the People's Republic of China and is under the jurisdiction of Beijing Chemical Reagent General Factory. This standard was drafted by Beijing Chemical Reagent General Factory. The main drafter of this standard was Liu Tianzhao.3V, when using a weak alkaline solution of ammonia-ammonium acetate as the supporting electrolyte solution, the pre-electrolysis potential should be positive to -1.7V.
6.3.6.2 At the selected pre-electrolysis potential, the sample itself cannot undergo an electrochemical reaction. 6.3.6.3 The selected pre-electrolysis potential should be more than 0.2V negative than the dissolution peak potential of the metal impurity to be measured under the measurement conditions. 6.3.7 Pre-electrolysis time
The pre-electrolysis time cannot be less than 1min and cannot be more than 10min. The pre-electrolysis time should be constant during the measurement process. The specific time depends on the concentration of the impurity to be measured, the sensitivity of the instrument, and the volume of the electrode. 6.3.8 Stop stirring time
\~ is generally 30s or 60s and cannot be extended. The selected stop stirring time in each measurement process should be consistent. 6.3.9 Scanning rate
Under the conditions specified in this general rule, the scanning rate is preferably 20 to 60mV/s. 132
GB 3914—83
In some cases, 10~100mV/s can be selected. For example, if the sensitivity of the impurities to be measured is to be increased, and the change of separation and capacitance current does not affect the determination, a scanning rate greater than 60mV/s can be used, but not greater than 100mV/s. 6.3.10 Scanning potential range
The scanning potential range should include all dissolution peaks of all impurities to be measured. 6.3.11 Release potential and release time
The release potential is -0.05V or -0.1V, and the release time is 1min or 2min. The release potential and release time should be constant during the determination process.
6.3.12 The amount of impurities added each time
The amount of the impurity standard added for the first time cannot be greater than the specification amount; the increase in the corresponding dissolution peak height caused by the electrochemical reaction of each added impurity amount cannot be less than 8mm, and the total amount of impurities added three times must be greater than the specification amount. 7 Method error
7.1 Precision
When formulating the method, calculate the relative standard deviation (Sr) when the number of measurements is not less than eleven. Sr<20% is required.
7.2 Recovery
The method recovery is required to be within the range of 80-120%. Safety precautions
8.1 When applying mercury, using and dissolving mercury on the mercury film electrode, be careful not to leave mercury in the laboratory. When the mercury film electrode is not used continuously, the mercury on the electrode should be dissolved and removed before storage. The laboratory should have exhaust equipment.
The laboratory should regularly test the content of mercury in the air, which is required to be lower than the national standard, that is, less than 0.01mg/m3. Physical examinations should be conducted regularly for personnel who have been engaged in this work for a long time. 8.2 The use of high-pressure nitrogen cylinders should be operated in accordance with the safety operation regulations of high-pressure cylinders. 133
Nouns and terms
Anodic stripping voltammetry
Mercury film electrode
Silver-based film electrode
Working electrode
Reference electrode
Counter electrode
GB 3914—83
Appendix A
Table of terms, terms and symbols
(Supplement)
anodic stripping voltammetrymercury film electrode
mercury film electrode on silver supportworking electrode
reference electrode
counter electrode
deaerate
supporting electrolyte solution supporting electrolyte solution
electrolytic cell
pre - electrolysis potential
pre - electrolysis time
stop stirring time
potential scan range
scan rate
stripping peak potential
stripping peak current
standard addition method
impurities added
release potential
release time
intermetallic compound
1interfering substance
detection limit
relative standard deviation
recovery rate
linear range
electrolytic cell
pre - electrolysis potentialpre - electrolysis time
stop stirring time
potential scan range
scan rate
stripping peak potential
stripping peak current
standard addition
impurity added
rest potential
rest period
intermetallic compound
interferent
detection limit
relative standard deviation
recovery percent
range of linear response
mV/s
nanogram/ml
percent
percent
unit symbol
synonyms
anodic dissolution method, etc.
electrolysis of blood, etc.
electrolysis potential
electrolysis time
intermetallic compound
detection limit
coefficient of variation
B.1 Instrument
GB 3914—83
Appendix B
Conditions to be given in product technical standards
(Supplement)
According to the provisions of Chapter 4 of GB391483 "General Rules for Extreme Stripping Voltammetry of Chemical Reagents". B.2 Chemical reagents
According to the provisions of Chapter 5 of GB3914--83.
B.3 Determination
B.3.1 Determination conditions
Pre-electrolysis potential V;
Scanning potential range V,
Dissolution peak potential,
B.3.2 Determination procedure
Required to give the sample amount (g), sample treatment method, supporting electrolyte solution composition and added volume (ml): other necessary conditions.
B.4 Calculation
According to the provisions of GB3914--836.2.
Additional Notes:
This standard was proposed by the Ministry of Chemical Industry of the People's Republic of China and is under the jurisdiction of Beijing Chemical Reagent General Factory. This standard was drafted by Beijing Chemical Reagent General Factory. The main drafter of this standard was Liu Tianzhao.3V, when using a weak alkaline solution of ammonia-ammonium acetate as the supporting electrolyte solution, the pre-electrolysis potential should be positive to -1.7V.
6.3.6.2 At the selected pre-electrolysis potential, the sample itself cannot undergo an electrochemical reaction. 6.3.6.3 The selected pre-electrolysis potential should be more than 0.2V negative than the dissolution peak potential of the metal impurity to be measured under the measurement conditions. 6.3.7 Pre-electrolysis time
The pre-electrolysis time cannot be less than 1min and cannot be more than 10min. The pre-electrolysis time should be constant during the measurement process. The specific time depends on the concentration of the impurity to be measured, the sensitivity of the instrument, and the volume of the electrode. 6.3.8 Stop stirring time
\~ is generally 30s or 60s and cannot be extended. The selected stop stirring time in each measurement process should be consistent. 6.3.9 Scanning rate
Under the conditions specified in this general rule, the scanning rate is preferably 20 to 60mV/s. 132
GB 3914—83
In some cases, 10~100mV/s can be selected. For example, if the sensitivity of the impurities to be measured is to be increased, and the change of separation and capacitance current does not affect the determination, a scanning rate greater than 60mV/s can be used, but not greater than 100mV/s. 6.3.10 Scanning potential range
The scanning potential range should include all dissolution peaks of all impurities to be measured. 6.3.11 Release potential and release time
The release potential is -0.05V or -0.1V, and the release time is 1min or 2min. The release potential and release time should be constant during the determination process.
6.3.12 The amount of impurities added each time
The amount of the impurity standard added for the first time cannot be greater than the specification amount; the increase in the corresponding dissolution peak height caused by the electrochemical reaction of each added impurity amount cannot be less than 8mm, and the total amount of impurities added three times must be greater than the specification amount. 7 Method error
7.1 Precision
When formulating the method, calculate the relative standard deviation (Sr) when the number of measurements is not less than eleven. Sr<20% is required.
7.2 Recovery
The method recovery is required to be within the range of 80-120%. Safety precautions
8.1 When applying mercury, using and dissolving mercury on the mercury film electrode, be careful not to leave mercury in the laboratory. When the mercury film electrode is not used continuously, the mercury on the electrode should be dissolved and removed before storage. The laboratory should have exhaust equipment.
The laboratory should regularly test the content of mercury in the air, which is required to be lower than the national standard, that is, less than 0.01mg/m3. Physical examinations should be conducted regularly for personnel who have been engaged in this work for a long time. 8.2 The use of high-pressure nitrogen cylinders should be operated in accordance with the safety operation regulations of high-pressure cylinders. 133
Nouns and terms
Anodic stripping voltammetry
Mercury film electrode
Silver-based film electrode
Working electrode
Reference electrode
Counter electrode
GB 3914—83
Appendix A
Table of terms, terms and symbols
(Supplement)
anodic stripping voltammetrymercury film electrode
mercury film electrode on silver supportworking electrode
reference electrode
counter electrode
deaerate
supporting electrolyte solution supporting electrolyte solution
electrolytic cell
pre - electrolysis potential
pre - electrolysis time
stop stirring time
potential scan range
scan rate
stripping peak potential
stripping peak current
standard addition method
impurities added
release potential
release time
intermetallic compound
1 interfering substance
detection limit
relative standard deviation
recovery rate
linear range
electrolytic cell
pre - electrolysis potentialpre - electrolysis time
stop stirring time
potential scan range
scan rate
stripping peak potential
stripping peak current
standard addition
impurity added
rest potential
rest period
intermetallic compound
interferent
detection limit
relative standard deviation
recovery percent
range of linear response
mV/s
nanogram/ml
percent
percent
unit symbol
synonyms
anodic dissolution method, etc.
electrolysis of blood, etc.
electrolysis potential
electrolysis time
intermetallic compound
detection limit
coefficient of variation
B.1 Instrument
GB 3914—83
Appendix B
Conditions to be given in product technical standards
(Supplement)
According to the provisions of Chapter 4 of GB391483 "General Rules for Extreme Stripping Voltammetry of Chemical Reagents". B.2 Chemical reagents
According to the provisions of Chapter 5 of GB3914--83.
B.3 Determination
B.3.1 Determination conditions
Pre-electrolysis potential V;
Scanning potential range V,
Dissolution peak potential,
B.3.2 Determination procedure
Required to give the sample amount (g), sample treatment method, supporting electrolyte solution composition and added volume (ml): other necessary conditions.
B.4 Calculation
According to the provisions of GB3914--836.2.
Additional Notes:
This standard was proposed by the Ministry of Chemical Industry of the People's Republic of China and is under the jurisdiction of Beijing Chemical Reagent General Factory. This standard was drafted by Beijing Chemical Reagent General Factory. The main drafter of this standard was Liu Tianzhao.12 The amount of impurities added each time
The amount of impurity standard added for the first time cannot be greater than the specification amount; the increase in the corresponding dissolution peak height caused by the electrochemical reaction of each impurity addition cannot be less than 8mm, and the total amount of impurities added three times must be greater than the specification amount. 7 Method error
7.1 Precision
When formulating the method, calculate the relative standard deviation (S,) when the number of measurements is not less than eleven times. Sr<20% is required.
7.2 Recovery rate
The method recovery rate is required to be within the range of 80-120%. Safety precautions
8.1 When applying mercury, using and dissolving mercury on mercury film electrodes, be careful not to leave mercury in the laboratory. When using mercury film electrodes discontinuously, the mercury on the electrodes should be dissolved and removed before storage. The laboratory should have exhaust equipment.
The laboratory should regularly test the content of mercury in the air, which is required to be lower than the national standard, that is, less than 0.01mg/m3. Personnel who are engaged in this work for a long time should be subject to regular physical examination. 8.2 The use of high-pressure nitrogen cylinders should be carried out in accordance with the safety operation regulations of high-pressure cylinders. 133
Nouns and terms
Anodic stripping voltammetry
Mercury film electrode
Silver-based film electrode
Working electrode
Reference electrode
Counter electrode
GB 3914—83
Appendix A
Nouns, terms and symbols table
(Supplement)
anodic stripping voltammetrymercury film electrode
mercury film electrode on silver supportworking electrode
reference electrode
counter electrode
deaerate
supporting electrolyte solution supporting electrolyte solution
electrolytic cell
pre - electrolysis potential
pre - electrolysis time
stop stirring time
potential scan range
scan rate
stripping peak potential
stripping peak current
standard addition method
impurities added
release potential
release time
intermetallic compound
1 interfering substance
detection limit
relative standard deviation
recovery rate
linear range
electrolytic cell
pre - electrolysis potentialpre - electrolysis time
stop stirring time
potential scan range
scan rate
stripping peak potential
stripping peak current
standard addition
impurity added
rest potential
rest period
intermetallic compound
interferent
detection limit
relative standard deviation
recovery percent
range of linear response
mV/s
nanogram/ml
percent
percent
unit symbol
synonyms
anodic dissolution method, etc.
electrolysis of blood, etc.
electrolysis potential
electrolysis time
intermetallic compound
detection limit
coefficient of variation
B.1 Instrument
GB 3914—83
Appendix B
Conditions to be given in product technical standards
(Supplement)
According to the provisions of Chapter 4 of GB391483 "General Rules for Extreme Stripping Voltammetry of Chemical Reagents". B.2 Chemical reagents
According to the provisions of Chapter 5 of GB3914--83.
B.3 Determination
B.3.1 Determination conditions
Pre-electrolysis potential V;
Scanning potential range V,
Dissolution peak potential,
B.3.2 Determination procedure
Required to give the sample amount (g), sample treatment method, supporting electrolyte solution composition and added volume (ml): other necessary conditions.
B.4 Calculation
According to the provisions of GB3914--836.2.
Additional Notes:
This standard was proposed by the Ministry of Chemical Industry of the People's Republic of China and is under the jurisdiction of Beijing Chemical Reagent General Factory. This standard was drafted by Beijing Chemical Reagent General Factory. The main drafter of this standard was Liu Tianzhao.12 The amount of impurities added each time
The amount of impurity standard added for the first time cannot be greater than the specification amount; the increase in the corresponding dissolution peak height caused by the electrochemical reaction of each impurity addition cannot be less than 8mm, and the total amount of impurities added three times must be greater than the specification amount. 7 Method error
7.1 Precision
When formulating the method, calculate the relative standard deviation (S,) when the number of measurements is not less than eleven times. Sr<20% is required.
7.2 Recovery rate
The method recovery rate is required to be within the range of 80-120%. Safety precautions
8.1 When applying mercury, using and dissolving mercury on mercury film electrodes, be careful not to leave mercury in the laboratory. When using mercury film electrodes discontinuously, the mercury on the electrodes should be dissolved and removed before storage. The laboratory should have exhaust equipment.
The laboratory should regularly test the content of mercury in the air, which is required to be lower than the national standard, that is, less than 0.01mg/m3. Personnel who are engaged in this work for a long time should be subject to regular physical examination. 8.2 The use of high-pressure nitrogen cylinders should be carried out in accordance with the safety operation regulations of high-pressure cylinders. 133
Nouns and terms
Anodic stripping voltammetry
Mercury film electrode
Silver-based film electrode
Working electrode
Reference electrode
Counter electrode
GB 3914—83
Appendix A
Nouns, terms and symbols table
(Supplement)
anodic stripping voltammetrymercury film electrode
mercury film electrode on silver supportworking electrode
reference electrode
counter electrode
deaerate
supporting electrolyte solution supporting electrolyte solution
electrolytic cell
pre - electrolysis potential
pre - electrolysis time
stop stirring time
potential scan range
scan rate
stripping peak potential
stripping peak current
standard addition method
impurities added
release potential
release time
intermetallic compound
1 interfering substance
detection limit
relative standard deviation
recovery rate
linear range
electrolytic cell
pre - electrolysis potentialpre - electrolysis time
stop stirring time
potential scan range
scan rate
stripping peak potential
stripping peak current
standard addition
impurity added
rest potential
rest period
intermetallic compound
interferent
detection limit
relative standard deviation
recovery percent
range of linear response
mV/s
nanogram/ml
percent
percent
unit symbol
synonyms
anodic dissolution method, etc.
electrolysis of blood, etc.
electrolysis potential
electrolysis time
intermetallic compound
detection limit
coefficient of variation
B.1 Instrument
GB 3914—83
Appendix B
Conditions to be given in product technical standards
(Supplement)
According to the provisions of Chapter 4 of GB391483 "General Rules for Extreme Stripping Voltammetry of Chemical Reagents". B.2 Chemical reagents
According to the provisions of Chapter 5 of GB3914--83.
B.3 Determination
B.3.1 Determination conditions
Pre-electrolysis potential V;
Scanning potential range V,
Dissolution peak potential,
B.3.2 Determination procedure
Required to give the sample amount (g), sample treatment method, supporting electrolyte solution composition and added volume (ml): other necessary conditions.
B.4 Calculation
According to the provisions of GB3914--836.2.
Additional Notes:
This standard was proposed by the Ministry of Chemical Industry of the People's Republic of China and is under the jurisdiction of Beijing Chemical Reagent General Factory. This standard was drafted by Beijing Chemical Reagent General Factory. The main drafter of this standard was Liu Tianzhao.2 The use of high-pressure nitrogen cylinders should be carried out in accordance with the safety regulations for high-pressure cylinders. 133
Nouns and terms
Anodic stripping voltammetry
Mercury film electrode
Silver-based film electrode
Working electrode
Reference electrode
Counter electrode
GB 3914—83
Appendix A
Table of nouns, terms and symbols
(Supplement)
anodic stripping voltammetrymercury film electrode
mercury film electrode on silver supportworking electrode
reference electrode
counter electrode
deaerate
supporting electrolyte solution supporting electrolyte solution
electrolytic cell
pre - electrolysis potential
pre - electrolysis time
stop stirring time
potential scan range
scan rate
stripping peak potential
stripping peak current
standard addition method
impurities added
release potential
release time
intermetallic compound
1 interfering substance
detection limit
relative standard deviation
recovery rate
linear range
electrolytic cell
pre - electrolysis potentialpre - electrolysis time
stop stirring time
potential scan range
scan rate
stripping peak potential
stripping peak current
standard addition
impurity added
rest potential
rest period
intermetallic compound
interferent
detection limit
relative standard deviation
recovery percent
range of linear response
mV/s
nanogram/ml
percent
percent
unit symbol
synonyms
anodic dissolution method, etc.
electrolysis of blood, etc.
electrolysis potential
electrolysis time
intermetallic compound
detection limit
coefficient of variation
B.1 Instrument
GB 3914—83
Appendix B
Conditions to be given in product technical standards
(Supplement)
According to the provisions of Chapter 4 of GB391483 "General Rules for Extreme Stripping Voltammetry of Chemical Reagents". B.2 Chemical reagents
According to the provisions of Chapter 5 of GB3914--83.
B.3 Determination
B.3.1 Determination conditions
Pre-electrolysis potential V;
Scanning potential range V,
Dissolution peak potential,
B.3.2 Determination procedure
Required to give the sample amount (g), sample treatment method, supporting electrolyte solution composition and added volume (ml): other necessary conditions.
B.4 Calculation
According to the provisions of GB3914--836.2.
Additional Notes:
This standard was proposed by the Ministry of Chemical Industry of the People's Republic of China and is under the jurisdiction of Beijing Chemical Reagent General Factory. This standard was drafted by Beijing Chemical Reagent General Factory. The main drafter of this standard was Liu Tianzhao.2 The use of high-pressure nitrogen cylinders should be carried out in accordance with the safety regulations for high-pressure cylinders. 133
Nouns and terms
Anodic stripping voltammetry
Mercury film electrode
Silver-based film electrode
Working electrode
Reference electrode
Counter electrode
GB 3914—83
Appendix A
Table of nouns, terms and symbols
(Supplement)
anodic stripping voltammetrymercury film electrode
mercury film electrode on silver supportworking electrode
reference electrode
counter electrode
deaerate
supporting electrolyte solution supporting electrolyte solution
electrolytic cell
pre - electrolysis potential
pre - electrolysis time
stop stirring time
potential scan range
scan rate
stripping peak potential
stripping peak current
standard addition method
impurities added
release potential
release time
intermetallic compound
1 interfering substance
detection limit
relative standard deviation
recovery rate
linear range
electrolytic cell
pre - electrolysis potentialpre - electrolysis time
stop stirring time
potential scan range
scan rate
stripping peak potential
stripping peak current
standard addition
impurity added
rest potential
rest period
intermetallic compound
interferent
detection limit
relative standard deviation
recovery percent
range of linear response
mV/s
nanogram/ml
percent
percent
unit symbol
synonyms
anodic dissolution method, etc.
electrolysis of blood, etc.
electrolysis potential
electrolysis time
intermetallic compound
detection limit
coefficient of variation
B.1 Instrument
GB 3914—83
Appendix B
Conditions to be given in product technical standards
(Supplement)
According to the provisions of Chapter 4 of GB391483 "General Rules for Extreme Stripping Voltammetry of Chemical Reagents". B.2 Chemical reagents
According to the provisions of Chapter 5 of GB3914--83.
B.3 Determination
B.3.1 Determination conditions
Pre-electrolysis potential V;
Scanning potential range V,
Dissolution peak potential,
B.3.2 Determination procedure
Required to give the sample amount (g), sample treatment method, supporting electrolyte solution composition and added volume (ml): other necessary conditions.
B.4 Calculation
According to the provisions of GB3914--836.2.
Additional Notes:
This standard was proposed by the Ministry of Chemical Industry of the People's Republic of China and is under the jurisdiction of Beijing Chemical Reagent General Factory. This standard was drafted by Beijing Chemical Reagent General Factory. The main drafter of this standard was Liu Tianzhao.
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