Ammonium hydrogen carbonate for industrial use (including foodstuffs) — Determination of arsenic content — Silver diethyldithiocarbamate photometric method

Applicable to products having As contents more than 0.2 mg/kg. The principle consists in reduction of the element to arsine in a solution of silver diethyldithiocarbamate in pyridine. Photometric measurement of the purplish- red colour produced by the colloidally dispersed silver, at the maximum of the absorption curve (wavelength approximately 540 nm).