GB/T 5121.22-1996 Chemical analysis methods for copper and copper alloys - Determination of cadmium content

This standard specifies the determination method of cadmium content in copper and copper alloys. This standard is applicable to the determination of cadmium content in copper and copper alloys. Determination range: 0.50% to 1.50%. GB/T 5121.22-1996 Chemical analysis method for copper and copper alloys Determination of cadmium content GB/T5121.22-1996 Standard download decompression password: www.bzxz.net

1 Scope
National Standard of the People's Republic of China
Chemical analysis method for copper and copper alloys - Determination of cadmium content This standard specifies the method for determination of cadmium content in copper and copper alloys. GB/T5121.22—1996
This standard is applicable to the determination of cadmium content in copper and copper alloys. Determination range: 0.50% to 1.50%. 2 Reference standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When this standard is published, the versions shown are valid. All standards will be revised, and parties using this standard should explore the possibility of using the latest versions of the following standards. GB1.4-88 Standardization work guidelines for chemical analysis method standards GB1467-78 General principles and general provisions for chemical analysis methods for metallurgical products GB7728-87 General principles for chemical analysis of metallurgical products by flame atomic absorption spectrometry 3 Method summary
The sample is dissolved in nitric acid, and the absorbance of cadmium is measured at a wavelength of 228.8nm using an air-acetylene flame on an atomic absorption spectrometer. 4 Reagents
4.1 Nitric acid (1+1).
4.2 Copper solution (1600μg/mL): Weigh 0.4000g of electrolytic copper without cadmium into a 150ml beaker, add 5mL nitric acid (4.1), heat until completely dissolved, transfer to a 250mL volumetric flask, dilute to scale with water, mix well, 4.3 Cadmium standard solution: Weigh 0.1000g of pure, place in a 250mL beaker, add 20ml hydrochloric acid (1+3), heat until completely dissolved. Transfer to a 1000mL volumetric flask, dilute to scale with water, mix well. This solution contains 100μg cadmium per ml. 5 Instruments
Atomic absorption spectrometer with cadmium hollow cathode lamp. Under the best working conditions of the instrument, any instrument that can meet the following indicators can be used. Sensitivity: In a solution consistent with the matrix of the measured sample solution, the characteristic concentration of cadmium should not be greater than 0.034μg/mL. Precision: Measure the absorbance 10 times with the highest concentration standard solution, and its standard deviation shall not exceed 1.0% of the average absorbance: Measure the absorbance 10 times with the lowest concentration standard solution (not the "zero" standard solution), and its standard deviation shall not exceed 0.5% of the average absorbance of the highest standard solution.
Linearity of working curve: Divide the working curve into five sections according to concentration, and the ratio of the absorbance difference of the highest section to the absorbance difference of the lowest section shall not be less than 0.7.
Instrument L operating conditions are shown in Appendix A (Suggested Appendix) Approved by the State Administration of Technical Supervision on November 4, 1996 291
Implemented on April 1, 1997
6 Analysis steps
6.1 Test materials
GB/T 5121. 22-1996
Weigh 0.400g of sample, accurate to 0.0001g. Perform two independent determinations and take the average value. 6.2 Blank test
Perform a blank test with the sample. wwW.bzxz.Net
6.3 Determination
6.3.1 Place the sample (6.1) in a 150mL beaker, add 5mL nitric acid to cover the surface, heat at low temperature until completely dissolved, boil, remove nitrogen oxides, and cool. Transfer to a 250mL volumetric flask, dilute to scale with water, and mix. 6.3.2 Transfer 10.00mL of the solution to a 100mL volumetric flask. Add 5mL nitric acid and dilute to scale with water, mix. 6.3.3 Using an air-acetylene flame, at a wavelength of 228.8nm on an atomic absorption spectrometer, adjust with water at the same time as the standard solution series, measure the absorbance of the test solution, subtract the absorbance of the blank solution accompanying the sample, and calculate the corresponding concentration of nitrogen from the working curve. 6.4 Drawing of working curve
6.4.1 Transfer 0, 0.50, 1.00, 1.50, 2.00, 2.50 ml of cadmium standard solution into a set of 100 ml volumetric flasks, add 10 ml of copper solution and 5 ml of nitric acid respectively, dilute to the scale with water and mix well. 6.4.2 Measure the absorbance of the standard solution under the same conditions as the test solution, subtract the absorbance of the "zero" concentration solution in the standard series, and draw a working curve with cadmium concentration as the horizontal axis and absorbance as the vertical axis. 7 Expression of analysis results
Calculate the percentage of cadmium according to formula (1):
Cd(%) = : Vu · V, × 10\s
Where: ——Cadmium concentration obtained from the working curve, ug/mLVo—Total volume of test solution, mL;
V,-Volume of diluted test solution after one aliquot, mL; V,-Volume of test solution after one aliquot, mL;
ma——Mass of the test material, g.
The obtained results are expressed to two decimal places.
8 Allowable difference
The difference in analysis results between laboratories should not exceed 0.05%, X100
GB/T 5121. 22—1996
(Appendix of Prompt)
Instrument Working Conditions
The working conditions for determining the amount of cadmium using a WFX-1D atomic absorption spectrometer are shown in Table A1. Table A1
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