YS/T 281.4-2011Methods for chemical analysis of cobalt. Part 4: Determination of arsenic content. Molybdenum blue spectrophotometry (English PDF)

Foreword

YS/T 281 "cobalt chemical analysis method" is divided into the following 20 parts.

Part 1. Determination of iron content - Sulfosalicylic acid spectrophotometric method Part 2. Determination of aluminum content - Chromazu S spectrophotometric method Part 3. Determination of silicon content - Molybdenum blue spectrophotometric method Part 4. Determination of arsenic content - Molybdenum blue spectrophotometric method - Part 5. Determination of phosphorus content - Molybdenum blue spectrophotometric method Part 6. Determination of magnesium content - Flame atomic absorption spectrometric method - Part 7. Determination of zinc content - Flame atomic absorption spectrometric method Part 8. Determination of cadmium content - Flame atomic absorption spectrometric method Part 9. Determination of lead content - Flame atomic absorption spectrometric method Part 10. Determination of nickel content - Flame atomic absorption spectrometric method - Part 11. Determination of copper and manganese - Flame atomic absorption spectrometric method - Part 12. Determination of arsenic, antimony, bismuth, tin and lead - Electrothermal atomic absorption spectrometry - Part 13. Determination of sulfur content - High frequency induction furnace combustion infrared absorption method - Part 14. Determination of carbon content - High frequency induction furnace combustion infrared absorption method - Part 15. Determination of arsenic, antimony and bismuth - Hydride generation - atomic fluorescence spectrometry - Part 16. Determination of the amount of arsenic, cadmium, copper, zinc, lead, bismuth, tin, antimony, silicon, manganese, iron, nickel, aluminum and magnesium.

Spectrum method

- Part 17. Determination of aluminum, manganese, nickel, copper, zinc, cadmium, tin, antimony, lead and bismuth inductively coupled plasma mass spectrometry - Part 18. Determination of sodium content - Flame atomic absorption spectrometric method - Part 19. Determination of calcium, magnesium, manganese, iron, cadmium and zinc - Inductively coupled plasma emission spectrometric method - Part 20. Determination of the amount of oxygen - Infrared absorption method this part is part 4 of YS/T 281.

This part is drafted in accordance with the rules given in GB/T 1.1-2009.

This part replaces YS/T 281.4-1994 "cobalt chemical analysis method molybdenum blue spectrophotometric determination of arsenic". With YS/T 281.4-1994, this section has the following main changes.

- the lower limit of determination from 0.0015% to 0.00010%;

--- The text format has been modified to supplement the quality assurance and control terms, increasing the repeatability and reproducibility limits;

- Added the requirements for the test report.

This part of the National Nonferrous Metals Standardization Technical Committee (SAC/TC243) proposed and centralized.

This standard is responsible for drafting units. Jinchuan Group Co., Ltd., Beijing Mining and Metallurgy Research Institute.

This part is responsible for drafting units. Zhejiang Huayou Cobalt Industry Co., Ltd.

This part participates in the drafting unit. Jinchuan Group Co., Ltd., Beijing Mining and Metallurgy Research Institute.

1 Scope

This part of YS/T 281 specifies the determination of arsenic in cobalt.

This part applies to the determination of arsenic in cobalt. Measuring range. 0.00010% ~ 0.0050%.

2 Method summary

The sample was dissolved with nitric acid. In the acidic solution, arsenic molybdenum heteropoly acid complex formed by arsenic (V) and ammonium molybdate is replaced by ethyl acetate-n-butanol Mixed solvent extraction, reduction with stannous chloride to molybdenum blue, and the absorbance was measured at a wavelength of 650 nm at a spectrophotometer.

3 Reagent

If no special instructions, the reagents used for the analysis of pure reagents, preparation and analysis of water are secondary distilled water or considerable purity of the experiment Room water.

3.1 sodium hydroxide, excellent grade pure.

3.2 anhydrous sodium sulfate, excellent grade pure.

3.3 Ammonium molybdate [(NH4) 6Mo7O24 · 4H2O], excellent grade pure.

3.4 nitric acid (rho = 1.42g/mL), excellent grade pure.

3.5 ammonium hydroxide (rho = 0.88g/mL), high purity.

3.6 Trichloromethane.

3.7 n-butanol.

3.8 Ethyl acetate.

3.9 nitric acid (3 2).

3.10 nitric acid (1 1).

Note. with the exclusion of nitrogen oxides in the preparation of nitric acid.

3.11 Sodium hydroxide solution (20 g/L).

3.12 times sodium bromate solution. take 45mL saturated bromine water in a plastic bottle, add 30mL sodium hydroxide solution (3.11), 165mL water, Mix well.

3.13 Ammonium molybdate [(NH4) 6Mo7O24 · 4H2O] solution (50g/L). Filter with a slow quantitative filter paper in a plastic bottle.

3.14 Phosphorus Extract. Three Trichloromethane is mixed with a portion of n-butanol.

3.15 Arsenic Extract. One portion of ethyl acetate is mixed with a portion of n-butanol.

3.16 Sulfuric acid wash solution. add 70mL sulfuric acid (rho = 1.84g/mL) in 840mL water, then add 30mL ammonium molybdate solution (3.13) 60mL n-butanol, mix well.

3.17 Reduction Solution A. Dissolve 1 g of stannous chloride (SnCl2 · 2H2O) in 80 mL of hydrochloric acid (rho = 1.19 g/mL).