适用于砷含量超过0.2 mg/kg的产品。其原理是在二乙基二硫代氨基甲酸银与吡啶的溶液中将元素还原为砷化氢。在吸收曲线最大值（波长约540nm）处，对胶体分散银产生的紫红色进行光度测量。

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).