Hydroxylammonium arsenate chloride

Merry and Zarcinas [33] have described a silver diethyldithiocarbamate method for the determination of arsenic and antimony in soil. The method involves the addition of sodium tetrahydroborate to an acid-digested sample which has been treated with hydroxylammonium chloride to prevent the formation of insoluble antimony compounds. The generated arsine and stib-ine react with a solution of silver diethyldithiocarbamate in pyridine in a gas washtube. Absorbance is measured twice at wavelengths of 600 and 504 nm. 

Hydroxylammonium salts are reagents usually employed as sources of hydroxylamine for various inorganic and organic reactions. The chloride and sulfate are the better known commercially available salts obtained by the hydrolysis of the nitroparaffins. The phosphate, " arsenate, ... 

Arsenic, selenium, and antimony can be measured at low concentrations with HG-AAS. Digestion with aqua regia in a microwave oven is necessary prior to the determination. Next, hydroxylammonium chloride is added as a neutral solution iodide may be added to accelerate the reaction. For arsenic or antimony a reducing agent such as ascorbic acid has to be added to convert all arsenic or antimony to a single oxidation state. A background correction is required for this purpose apparatus with a deuterium lamp corrector can be used but Zeeman background correction is preferred. 

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