GB/T 4373.4-1984 Chemical analysis method for arsenic - Determination of bismuth content by diantipyryl methane disulfide spectrophotometry GB/T4373.4-1984 standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Methods for chemical analysis of arsenicThe dithiodiantipyryl methane photometricmethod for the determination of bismuth contentThis standard is applicable to the determination of bismuth content in arsenic. Determination range: 0.010～0.200%. UDC 669.778 : 543
.42:546.87
GB 4373.4—84
This standard complies with GB1467--78 "General Principles and General Provisions of Chemical Analysis Methods for Metallurgical Products". "Method Summary
The sample is dissolved in hydrochloric acid and nitric acid, evaporated to nearly 1, and a few drops of hydrochloric acid and a small amount of water are added to dissolve, and the acidity of the solution is adjusted to pH 3-1. After adding the color developer to develop color, its absorbance is measured at a wavelength of 520nm on a spectrophotometer. The presence of less than 100ug of copper and silver and less than 20μg of pot, selenium, and sieve in the color development solution does not affect the determination. 2 Reagents
2.1 Hydrochloric acid (specific gravity 1.19).
2.2 Hydrochloric acid (1 +1).
2.3 Nitric acid (specific gravity 1.42).
2.4 Ammonium hydroxide (1+1).
2.5 Acid solution (25).
2.6 Ascorbic acid solution (5%).
2.7 Color developer solution: Weigh 0.2g dithiocarbazine, place in a 100ml beaker, add 20ml anhydrous alcohol, 20ml glacial acetic acid and 160ml water, heat slightly to dissolve, filter and put into a plastic bottle for later use. 2.8 Bismuth standard storage solution: Weigh 0.5000g pure bismuth (99.9% or more), place in a 100ml beaker, add 10ml water and 1ml nitric acid (2.3), heat to dissolve, and continue to evaporate to 1-2ml. After cooling slightly, add 20ml nitric acid (1+9), boil, remove from the cold and transfer to a 500ml bottle. Dilute to scale with nitric acid (1+9) and mix well. This solution contains 1.0mg bismuth per ml. 2.9 Standard solution: Pipette 50.00 ml of standard storage solution (2.8) into a 500 ml bottle, dilute to scale with magnetic acid (1+9), and mix with a spoon. This solution contains 0.10 mg bismuth in 1 ml. 3 Instrument
Spectrophotometer.
4 Sample
Arsenic sample must be sieved through an 80 mesh sieve, and the diameter of the sieve should not exceed 12 mm. 4.2 After adding 1, the sample is stored in a desiccator, weighed on the same day for analysis, and weighed according to the ratio of sieve: 3:1. National Bureau of Standards 1984-04-30
1985-04-01
5 Analysis steps
5.1 Determination quantity
GB4373.4-84
Weigh two samples for determination and take the average value. 5.2 Sample quantity
Weigh the sample according to Table 1
0.010 ~0. 080
>0.080~0.200
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5.3 Determination
5.3.1 Place the sample (5.2) in a 100ml beaker, add 5ml hydrochloric acid (2.1) and 3ml nitric acid (2.3), cover with Table III, heat at low temperature to dissolve, continue to evaporate until nearly dry, remove and cool slightly. Add 6 drops of hydrochloric acid (2.1), wash Table III and the wall of the cup with water, boil for 2~3 minutes, and cool. Transfer the solution to a 50ml colorimetric tube, wash the beaker with water, and add the washing liquid to the colorimetric tube. 5.3.2 Add 2 ml of tartaric acid solution (2.5) and 2 ml of ascorbic acid solution (2.6), adjust the solution to pH 3-4 with ammonium hydroxide (2.4) and hydrochloric acid (2.2) (check with 0.5-5.0 pH test paper), add 4.0 ml of colorimetric solution (2.7), dilute to scale with water, and mix well.
5.3.3 Transfer part of the solution to 3 cm or 1 cm colorimetric III, use the reagent blank as reference, and measure its absorbance at a wavelength of 520 nm on a spectrophotometer.
5.3.4 Find the corresponding bismuth amount from the working curve. 5.4 Drawing of working curve
Pipette 0.00, 1.00, 2.00, 3.00, 4.00, 5.00 ml of standard solution (2.9), place them in a set of 50 ml colorimetric tubes respectively, and proceed as per 5.3.2-5.3.3. Draw the working curve with the amount as the horizontal axis and the absorbance as the vertical axis. 6 Calculation of analysis results
Calculate the percentage of bismuth according to the following formula:
Wherein: m, the amount of bismuth found from the working curve, mg; mo—sample amount, g.
The analysis results are expressed to three decimal places. 7 Allowable difference
mo×10bzxZ.net
The difference in analysis results between laboratories should not be greater than the allowable difference listed in Table 2. 301
0.010~0.040
0.040~0.100
0.100~0.200
GB4373.4—84
Additional remarks:
This standard was proposed by China Nonferrous Metals Industry Corporation. This standard was drafted by Hunan Shuikoushan Mining Bureau. This standard was drafted by the Hunan Shuikoushan Mining Bureau Research Institute. The main drafters of this standard are Ling Zonggan and Liu Binbin.
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