GB/T 5121.19-1996 Chemical analysis methods for copper and copper alloys - Determination of silver content

This standard specifies the determination method of silver content in copper and copper alloys. This standard is applicable to the determination of silver content in copper and copper alloys. Determination range: 0.050% to 0.15%. GB/T 5121.19-1996 Chemical analysis method for copper and copper alloys Determination of silver content GB/T5121.19-1996 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 silver content
Copper and copper alloys-Determination of silver contentThis standard specifies the method for determining the silver content in copper and copper alloys. This standard is applicable to the determination of the silver content in copper and copper alloys. Determination range: 0.050%~～0.15%. 2 Referenced standards
GB/T 5121. 79 -1996
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 are subject to revision, and parties using this standard should explore the possibility of using the latest versions of the following standards. GB1.4-88 Guidelines for Standardization Work Provisions for the Preparation of Chemical Analysis Methods GB1467-78 General Principles and General Provisions for Chemical Analysis Methods for Metallurgical Products GB7728--87 General Principles for Flame Atomic Absorption Spectrometry for Chemical Analysis of Metallurgical Products 3 Method Summary
The sample is dissolved in nitric acid. Using an air-acetylene flame, measure the absorbance of silver at a wavelength of 328.1nm on an atomic absorption spectrometer. 4 Reagents
4.1 Nitric acid (1+1).
4.2 Copper solution: Weigh 5.000g of pure copper (Ag<0.0010%) and place it in a 500mL beaker, add 40mL of nitric acid (4.1), heat to dissolve, boil to remove nitrogen oxides, and cool. Transfer to a 500ml volumetric flask, dilute to scale with water, and mix well. This solution contains 10mg of copper in 1mL.
4.3 Silver standard stock solution: weigh 1.0000g pure silver and place it in a 150mL beaker, add 10ml nitric acid (4.1), heat to dissolve, boil to remove nitrogen oxides, and cool. Transfer to a 1000ml volumetric flask, dilute to scale with water, and mix. This solution contains 1mg silver in 1ml. 4.4 Silver standard solution: transfer 15.00ml silver standard stock solution to a 500mL volumetric flask, add 10mL nitric acid (4.1), dilute to scale with water, and mix. This solution contains 30μg silver in 1ml. 5 Instrument
Atomic absorption spectrometer with silver 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 measurement solution, the characteristic concentration of silver should not exceed 0.015μg/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.
Working curve linearity: 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 be approved by the State Administration of Technical Supervision on November 4, 1996 286
Implementation on April 1, 1997
not less than 0.90 yuan
GB/T5121.19-1996
Instrument working conditions are shown in Appendix A (Reminder Appendix). 6 Analysis steps
6.1 Test sample
Weigh 0.200g of sample, accurate to 0.0001g, and measure twice independently, taking the average value. 6.2 Room white test
Carry out a blank test with the test sample.
6.3 Determination
6.3.1 Place the test sample (6.1) in a 150mL beaker, add 10ml of nitric acid, heat to dissolve, boil to remove nitrogen oxides, and cool. Transfer to a 200ml volumetric flask, dilute to the mark with water, and mix well. 6.3.2 Using an air-acetylene flame, at a wavelength of 328.1nm on an atomic absorption spectrometer, adjust to zero with water at the same time as the standard solution series, and measure the absorbance of the solution. Subtract the absorbance of the blank solution accompanying the sample from the measured absorbance, and find the corresponding silver concentration from the working curve. 6.4 Drawing of the working curve
6.4.1 Transfer 0.2.00.4.00, 6.00, 8.00, 10.00mL of the silver standard solution to a 200mL volumetric flask, add 20mL of copper solution and 10mL of nitric acid, dilute to the mark with water, and mix well. 6.4.2 Use air-acetylene flame to zero the atomic absorption spectrometer at a wavelength of 328.1nm with water, measure the absorbance of the solution, subtract the absorbance of the "zero" concentration solution of the standard solution series, and draw the working curve with silver concentration as the horizontal axis and absorbance as the vertical axis. 7 Expression of analytical results
Calculate the percentage of silver according to formula (1):
c·V× 10 6bzxZ.net
Ag(%)
Silver concentration of the test solution obtained from the working curve, ug/mL: Where: (—
V-total volume of the test solution, mL;
-mass of the test material,.
The result is expressed to two decimal places. If the silver content is less than 0.10%, it is expressed to 3 decimal places. 8 Allowable difference
The difference in analysis results between laboratories should not be greater than (.010%. 1
GB/T5121.19.---1996
Appendix A
(Suggestive Appendix)
Instrument working conditions
The working conditions for determining the amount of silver using Hitachi 508 atomic absorption spectrometer are shown in Table A1. Table A1
Input 0.18 Output 0.18
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