YS/T 226.4-2009Methods for chemical analysis of selenium. Part 4: Determination of mercury content. Dithizone-carbon tetrachloride titrated colorimetric-method (English PDF)

Foreword

YS/T 226 "selenium chemical analysis method" is divided into 13 parts.

--- Part 1. Determination of bismuth content - Hydride Generation - Atomic Fluorescence Spectrometry

--- Part 2. Determination of antimony content Hydride Generation - Atomic Fluorescence Spectrometry

--- Part 3. Determination of aluminum content Chromazurol S- cetylpyridinium bromide spectrophotometric method

--- Part 4. Determination of mercury content of dithizone - CTC colorimetric titration

--- Part 5. Determination of the amount of silicon molybdenum blue spectrophotometry

--- Part 6. Determination of sulfur content symmetrical diphenyl semicarbazide spectrophotometry

--- Part 7. Determination of magnesium content - Flame atomic absorption spectrometry

--- Part 8. Determination of copper content - Flame atomic absorption spectrometry

--- Part 9. Determination of iron content by flame atomic absorption spectrometry

--- Part 10. Determination of nickel content by flame atomic absorption spectrometry

--- Part 11. Determination of lead content by flame atomic absorption spectrometry

--- Part 12. Determination of the amount of selenium sodium thiosulfate volumetric method

--- Part 13. silver, aluminum, arsenic, boron, mercury, bismuth, copper, cadmium, iron, gallium, indium, magnesium, nickel, lead, silicon, antimony, tin, tellurium, titanium, zinc content of electricity Inductively coupled plasma mass spectrometry this section YS/T Part 4 226.

The partial replacement of YS/T 226.5-1994 "Determination of the amount of mercury and selenium dithizone - CTC titration colorimetry." And YS/T 226.5-Compared to 1994, this section has the following main changes.

--- Text format has been modified;

--- Supplementary terms of quality assurance and control;

--- Increase the repeatability limit, will be allowed to poor reproducibility limit.

The non-ferrous metal part by the National Standardization Technical Committee and centralized.

This section is responsible for drafting unit. Jinchuan Group Limited.

This section is drafted. Beijing Nonferrous Metal Research Institute.

Participated in the drafting of this section. Jinchuan Group Co., Ltd., Guangzhou Nonferrous Metal Research Institute.

1 Scope

This section YS/T 226 specifies the method for determination of selenium in the amount of mercury.

This section applies to the determination of the amount of mercury and selenium. Measurement range. 0.0005% to 0.04%.

2 Method summary

The sample is dissolved in nitric acid, mercury with dithizone in pH4 ~ pH5 acid medium - carbon tetrachloride generated orange-red complex, take into Titrated colorimetric assay.

There edetate sodium in the presence of selenium impurity element other than silver outer not interfere with the determination. Interference silver, plus ammonium thiocyanate masking.

3 Reagents

The standard water is deionized water, conductivity is not more than 6.67 × 10-2µS · cm-1.

Nitrate 3.1 (rho1.42g/mL).

3.2 nitric acid (1 + 1).

3.3 Disodium ethylenediaminetetraacetate solution (50g/L).

3.4 ammonium acetate solution (500g/L).

Ammonia 3.5 (1 + 1).

3.6 ammonium thiocyanate solution (500g/L).

3.7 pairs Diphenylthiocarbazone. Take 1g of finely dithizone dissolved in 200mL of carbon tetrachloride was added 200mL ammonium hydroxide (1 + 100) in the dispensing Funnel thoroughly shaken. After standing stratification, carbon tetrachloride layer was charged to another separating funnel, plus ammonium hydroxide (1 + 100) (the volume can be adapted when reduction), repeat the operation until the last ammonium hydroxide was colorless. All ammonium hydroxide solutions were combined, washed with hydrochloric acid (1 + 1) Dropwise to precipitate all dithizone solution colorless. Precipitated dithizone filtered with a glass funnel, washed with water 2 to 3 times, left at 40 °C Right drying.

3.8 pairs Diphenylthiocarbazone - carbon tetrachloride solution (0.01g/L).