This standard specifies the determination method of tin content in bismuth. This standard is applicable to the determination of tin content in bismuth. Determination range: 0.0001%~0.0005%. GB/T 8220.10-1998 Chemical analysis method for bismuth Beryllium coprecipitation-spectrophotometric method for determination of tin content GB/T8220.10-1998 Standard download decompression password: www.bzxz.net

GB/T 8220. 10--1998
This standard is a revision of Appendix F of GB/T915-1995 "Bismuth". During the revision, the original organic extraction separation was changed to co-precipitation separation, which simplified the analysis steps.
This standard complies with:
GB/T1.4-1988 Standardization work guidelines for the preparation of chemical analysis method standards GB/T1467-1978 General principles and general provisions for chemical analysis method standards 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 "Standardization work guidelines Unit 1: Drafting and presentation rules for standards Part 1: Basic provisions for standard preparation". From the date of implementation, this standard will also replace Appendix F of GB/T915-1995 "Bismuth". This standard is proposed by China National Nonferrous Metals Industry Corporation. This standard is under the jurisdiction of the Standardization and Metrology Research Institute of China National Nonferrous Metals Industry Corporation. This standard was drafted by Zhuzhou Smelter. This standard was drafted by Zhuzhou Smelter.
The main drafters of this standard are Wang Xiren and Zhong Ming. 351
1 Scope
National Standard of the People's Republic of China
Chemical analysis method of bismuth
Determination of tin content-Coprecipitation with beryllium-photometric method
Methods for chemical analysis of bismuth-Determination of tin content-Coprecipitation with beryllium-photometric method This standard specifies the determination method of tin content in bismuth. This standard applies to the determination of tin content in bismuth. Determination range: 0.0001% to 0.0005%. 2 Summary of the method
GB/T 8220. 10— 1998
The sample is dissolved in nitric acid. In the presence of EDTA, in an ammoniacal medium, beryllium sulfate is used as a carrier to separate the precipitated tin from the main bismuth. In a 0.5mnl/1. sulfuric acid solution, the binary complex formed by Sn (N) and phenylacetone-bromohexadecyltrimethylamine is photometrically determined at a wavelength of 508nm on a spectrophotometer.
3 Reagents
The water used for preparation of solutions and analysis is double distilled water. 3.1 Nitric acid (pl.42 g/ml.).
3.2 Ammonia water (p0.90 g/ml.).
3.3 Beryllium sulfate solution (20g/L).
3.4 ​​Disodium ethylenediaminetetraacetic acid solution (300g/L): Weigh 300g disodium ethylenediaminetetraacetic acid (C1HuN,Naz0:·2H,0) in a 1000mL beaker, add about 800mL of water, adjust to completely dissolve with ammonia water (3.2), and dilute with water to 1000ml. 3.5 Ammonia washing solution (2+100).
3.6 Sulfuric acid solution (5mol/L).
3.7 Tartaric acid solution (50g/L).
3.8 Potassium permanganate solution (20g/1).
3.9 Ascorbic acid solution (50g/1), prepare it when needed. 3.70 Oxalic acid solution (0.05mol/1).
3.11 Bromo-+hexaalkyltrimethylamine (CTAB 6g/L): Weigh 6g CTAB in 1000mL water, dissolve under slight heat. 3.12 Phenylalcohol solution: Weigh 0.15g phenylalcohol in 500mL anhydrous ethanol, add 5ml sulfuric acid solution (3.6), shake to dissolve, use after 2 days. If there is insoluble residue, filter it before use. 3.13 Tin standard stock solution: Weigh 0.1000g metallic tin (=99.95%) in a 200ml beaker, add 10ml sulfuric acid (p1.84g/mL), heat to dissolve, evaporate until white sulfur trioxide smoke appears, cool, carefully wash the beaker wall with about 10mL water, transfer sulfuric acid solution (3.6) into a 500ml volumetric flask and dilute to the mark, mix well. This solution contains 0.2mg tin in 1mL. 3.14 Tin standard solution: Pipette 10.00 mL of the tin standard storage solution (3.13) into a 1000 mL volumetric flask. Dilute to the mark with sulfuric acid solution (3.6). Mix well. This solution contains 2 ug of tin per ml. 4 Instruments: Spectrophotometer. 5 Analysis steps: 5.1 Test material: Weigh 2.000 g of the sample. 5.2 Blank test: Perform a blank test with the test material.
5.3 Determination
5.3.1 Place the sample (5.1) in a 300mL beaker, add 8ml nitric acid (3.1), dry and low temperature to dissolve the sample completely, heat and boil to drive off nitrogen oxides, remove, and blow water to clean the surface and the wall of the beaker. 5.3.2 Add 10ml beryllium sulfate solution (3.3) and 14ml disodium ethylenediaminetetraacetic acid solution (3.4), dilute with water to a volume of about 100mL, stir. Heat to about 80C on an electric stove and remove. Neutralize with ammonia water (3.2) until beryllium oxide precipitates, then add 3ml in excess and heat to boiling, cool to room temperature with frequent shaking, and filter with medium-speed filter paper. Wash the beaker 4 times, wash the filter paper 5 times, and then wash the filter paper once with water. bZxz.net
5.3.3 Use 5-10 ml of hot sulfuric acid solution (3.6) to dissolve the precipitate in the original beaker in portions, and then wash the filter paper 3-1 times with hot water. 5.3.4 Evaporate the test solution on a hot plate until white sulfur trioxide smoke appears, add a few drops of nitric acid (3.1) to remove carbon, and continue heating and evaporating until the white smoke is gone. Remove and cool. Add 5 mL of sulfuric acid solution (3.6), and dissolve the salts in a low temperature place of an electric furnace with frequent shaking. Cool slightly, add 5 ml of tartaric acid solution (3.7), and transfer to a 50 ml volumetric flask with water to control the volume to about 25 ml. 5.3.5 Add 1-2 drops of potassium permanganate solution (3.8), let stand for 1-2 minutes, add 1 ml of ascorbic acid solution (3.9), 5 ml of oxalic acid solution (3.10), and mix each reagent. Add 5 mL CTAB (3.11) and 2.5 mL phenacyl benzoate solution (3.12). Dilute to the mark with water and mix well. Place at room temperature (15-25°C) for 10 min. 5.3.6 Transfer part of the test solution into a 3 cm absorption dish and measure its absorbance at a wavelength of 508 nm using the empty dish accompanying the sample as a reference on a spectrophotometer.
5.4 Drawing of working curve
5.4.1 Transfer 0.1.00, 2.00.3.00, 4.00.5.00ml of tin standard solution (3.14) to 50ml equal volume bottles respectively. Add 5ml of tartaric acid solution (3.6) to 5ml. Add 5ml of tartaric acid solution (3.7) and dilute to 25ml with water. Proceed as in 5.3.5. 5.4.2 Transfer part of the test solution to a 3cm absorption dish, use the reagent blank as reference, measure its absorbance at a wavelength of 508mm on a spectrophotometer, use the tin amount as the horizontal coordinate and the absorbance as the vertical coordinate, and draw a curve. 6 Calculation and expression of analysis results
Calculate the percentage of tin according to the following formula:
Sn(%) - mi × 10-
Wherein: m.\-·"The amount of tin found from the working curve, μg; ma-the mass of the sample in g.
The analysis result should retain two significant figures.
7 Allowable difference
The difference in analysis results between laboratories should not be greater than the allowable difference listed in the following table.353
0.00010~0.00030
0. 000 3～~ 0. 000 5
GB/T 8220. 10--1998
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