This Standard specifies the reagents and materials, apparatus, test procedures, result calculation and method precision in the determination of arsenic in coal by molybdenum blue spectrophotometric method and hydride generation - atomic absorption method.
This Standard is applicable to lignite, bituminous coal and anthracite.
2 Normative References
The following standards contain provisions which, through reference in this Standard, constitute provisions of this Standard. For dated references, subsequent amendments to (excluding corrigendum) or revisions of, any of these publications do not apply. However, all parties coming to an agreement according to this standard are encouraged to study whether the latest editions of these documents apply. For dated references, the latest editions (including all the amendments) apply.
GB/T 483 General Rules for Analytical and Testing Methods of Coal (GB/T 483-2007, ISO 1213-2: 1992, Solid Mineral Fuels - Vocabulary - Part 2: Terms Relating to Sampling, Testing and Analysis, NEQ)
GB/T 6682 Water for Analytical Laboratory Use - Specification and Test Methods (GB/T 6682-2008, ISO 3696: 1987, Water for Analytic Use - Specification and Test Methods, MOD)
3 Arsenic Molybdenum Blue Spectrophotometric Method (Arbitration)
3.1 Method Summary
The coal sample and Eschka reagent are mixed and ignited, the ignition product is dissolved with hydrochloric acid and added with reducing agent to reduce the pentavalent arsenic reduce to trivalent arsenic. Zinc granule is added and the hydrogen is released to make the arsenic form the arsenic hydride gas and release, then absorbed by iodine solution and oxidized to arsenic acid. The ammonium molybdate - hydrazine sulfate solution is added to make it generate arsenic molybdenum blue and then determined with a spectrophotometer.
