This standard specifies the determination method of silver and cadmium in bismuth. This standard is applicable to the determination of silver and cadmium in bismuth. Determination range: Ag: 0.0004%~0.0020%; Cd: 0.00005%~0.0002%. GB/T 8220.13-1998 Chemical analysis method for bismuth Determination of silver and cadmium by electrothermal atomic absorption spectrometry GB/T8220.13-1998 Standard download decompression password: www.bzxz.net

GB/T8220.13--1998
This standard is a revision of Appendix C and Appendix G of GB/T9151995 "Bismuth". During the revision, the flame atomic absorption method for determining the amount of silver in Appendix C was changed to the electrothermal atomic absorption method, and the determination methods of cadmium and silver were merged. This standard complies with:
GB/T1.4--1988 Standardization work guidelines for the preparation of chemical analysis methods GB/T1167-1978 General principles and general provisions for chemical analysis methods for metallurgical products GB/T7729-1987 General principles for spectrophotometric methods for chemical analysis of metallurgical products This standard is a supporting standard for GB/T915\-1995 "Bismuth". The preparation method of this standard complies with the provisions of GB/T1.1-1993 "Guidelines for standardization work Part 1: Basic provisions for standard preparation". Unit 1: Rules for drafting and expressing standards This standard shall replace Appendix C and Appendix G of GB/T915-1995 "Bismuth" from the date of implementation. Appendix A of this standard is a suggestive appendix.
This standard is proposed by China National Nonferrous Metals Industry Corporation. This standard is under the jurisdiction of the Standard and Metrology Institute of China National Nonferrous Metals Industry Corporation. This standard is drafted by Zhuzhou Smelter. This standard is drafted by Zhuzhou Smelter.
The main drafters of this standard: Zhu Lijuan, Zhang Dongfeng. 362
1 Scope
National Standard of the People's Republic of China
Chemical analysis methods of bismuth
Electrothermal atomic absorption spectrometric methodMethods for chemical analysis of hismuthDetermination of silver and cadmium contentElectrothermal atomic absorption spectrometric methodThis standard specifies the determination method of silver and cadmium in bismuth. GB/T8220. 13 -. 1998
This standard is applicable to the determination of silver and cadmium in bismuth. Determination range: Ag: 0.0004%~0.0020%; Cd: 0.00005%~0.0002%.
2 Method Summary
The sample is dissolved in nitric acid, and an appropriate amount of solution is introduced into the electrothermal atomizer. The absorbance of silver and cadmium is measured at the wavelength of 328.1nm228.8nm of the atomic absorption spectrometer, and the working curve is drawn by the matrix addition method to obtain the content of silver and cadmium in the sample. 3 Reagents
The water used for preparing the solution and the analysis is double distilled water. The experimental utensils are soaked in dilute nitric acid and then thoroughly cleaned with double distilled water. 3.1 Nitric acid (1+1), high-grade pure.
3.2 Nitric acid (2+98), high-grade pure. Www.bzxZ.net
3.3 Silver standard stock solution: Weigh 1.0000g of metallic silver (≥99.99%) into a 100mL beaker, add 20ml of nitric acid (3.1), cover with a watch glass, heat at low temperature until completely dissolved, remove, cool, transfer the solution into a 1000ml brown volumetric flask, dilute to scale with water, and mix well. This solution contains 1mg of silver per mL.
3.4 ​​Silver standard solution: Transfer 1.00mL of the silver standard stock solution (3.3) into a 100mL brown volumetric flask, dilute to scale with nitric acid (3.2), and mix well. 1mL of this solution contains 10μg silver. 3.5 Cadmium standard stock solution: Weigh 1.0000g of metallic cadmium (≥99.99%) into a 100ml beaker, add 20ml of nitric acid (3.1), cover with Table III, heat at low temperature until completely dissolved, remove, cool, transfer the solution into a 1000ml volumetric flask, dilute to scale with water, and mix. 1mL of this solution contains 1mg of silver.
3.6 Cadmium standard solution: Transfer 1.00mL of cadmium standard stock solution (3.5) into a 100mL volumetric flask, dilute to scale with nitric acid (3.2), and mix. 1mL of this solution contains 10μg cadmium.
3.7 Silver and cadmium mixed standard solution: Transfer 10.00mL of silver standard solution (3.4) and 1.00mL of cadmium standard solution (3.6) respectively, place in a 100mL volumetric flask, dilute to scale with nitric acid (3.2), and mix. 1 ml of this solution contains 1 μg silver and 0.1 μg cadmium respectively, 3.8 bismuth solution (100 mg/mL): weigh 10.00 g high-purity bismuth (≥99.999%), add 40 mL nitric acid (3.1) to a 250 mL high-type beaker, heat at low temperature until completely dissolved, remove, cool, transfer to a 100 mL volumetric flask, rinse the beaker with 5 mL nitric acid (3.1), and transfer to the volumetric flask, dilute to the mark with nitric acid (3.2), and mix. Approved by the State Administration of Quality and Technical Supervision on August 19, 1998, implemented on March 1, 1999
4 Instruments
GB/T 8220. 13--1998
Graphite furnace atomic absorption spectrometer (with buckle background device), with automatic sampler and silver and cadmium hollow cathode lamps. The instrument working conditions are shown in Appendix A (Reminder Appendix). 5 Analysis steps
5.1 Test sample
Weigh 0.5000g of sample.
5.2 Blank test
Perform a blank test with the sample.
5.3 Determination
5.3.1 Place the test sample (5.1) in a 25ml beaker, add 4.0mL nitric acid (3.1), cover with a watch glass, and heat at low temperature until completely dissolved. Remove, cool, transfer to a 50mL volumetric flask, dilute to scale with nitric acid (3.2), and mix. 5.3.2 Take 1.00mL of the test solution in a 10mL volumetric flask, dilute to scale with nitric acid (3.2), and mix. 5.3.3 Adjust the instrument parameters to the optimal state according to Appendix A, and adjust the electric thermal atomizer according to the selected conditions. Use the selected heating program to burn the graphite tube twice.
5.3.4 Inject the test solution into the atomizer and atomize according to the atomization program. Measure the absorbance of silver and cadmium at wavelengths of 328.1nm and 228.8nm respectively. Measure each test solution twice, take the average value, subtract the average value of the absorbance of the blank solution of the sample, and find the corresponding silver and cadmium concentrations on the working curve.
5.4 Drawing of the working curve
5.4.1 Transfer 0.0.20.0.40, 0.60.0.80, 1.00mL of the mixed standard solution of silver and cadmium (3.7) to a 50mL volumetric flask, add 0.5ml of bismuth solution (3.8) respectively, dilute to the scale with nitric acid (3.2), and mix well. 5.4.2 Under the same conditions as the test sample, measure the absorbance of the standard solution. Measure each solution twice, take the average value, subtract the average absorbance of the "zero" concentration solution in the standard series, and draw a working curve with the concentration of silver and cadmium as the horizontal axis and the average absorbance as the vertical axis.
6 Calculation and expression of analysis results
Calculate the percentage of silver and cadmium according to the following formula: X(%) =- c:V. -ViX 10-6
Where: c—concentration of the element to be measured from the working curve, g/mL; V. Total volume of test solution, mL;
V,—volume of the test solution, mL;
V2-—volume of the test solution taken, mL;
mThe mass of the test sample, g.
The analysis result should retain 2 significant figures.
7 Allowable Difference
The difference in analytical results between laboratories should not be greater than the allowable difference listed in the following table. 364
0. 000 4~0. 001 0
0. 001 0~0. 002 0
0. 000 05 ~0, 000 12
≥0. 000 12 ~ 0. 000 20
8220.13-1998
Allowance difference
GB/T8220.13-1998
Appendix A
(Suggestive appendix)
Instrument working conditions
Reference working conditions for determination of P.E3030B graphite absorption spectrometer and HGA-600 graphite furnace atomizer, see Table A! ：Table A1
Wavelength, nm
Slit, nm
Lamp current, mA
Graphite tube (PE)
Injection volume, uL
Atomization program,
Atomization
Pyrolytic coating plus platform
Time, 5
Ramp temperature rise
Pyrolytic coating plus platform
Ramp temperature rise
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