化妆品中各种形态的砷经硝酸镁高温氧化成５价砷，用碘化钾－抗坏血酸还原，经硼氢化钠氢化，原子吸收测定，线性范围为０．５～６．０ｍｇ／ｋｇ，相关系数０．９９９０～０．９９９９，最低检出浓度为０．２１ｍｇ／ｋｇ，本法测定的相对标准偏差为５．３％～１０．８％，加标回收率为９８％～１１０％。 Arsenic in various forms of cosmetics is oxidized to magnesium pentavalent by high temperature magnesium nitrate, reduced with potassium iodide-ascorbic acid, and determined by atomic absorption with sodium borohydride. The linear range is 0.5-6.0 mg/kg, and the correlation coefficient is 0. From 9990 to 0.9999, the minimum detectable concentration was 0.21 mg/kg. The relative standard deviation (RSD) determined by this method was 5.3% to 10.8%, and the recoveries were 98% to 110%.