Arsenic in cosmetic can be reduced by KBH 4 to form AsH 3,which can react with new silver salt to form a colored product.

• 利用硼氢化钾片将化妆品中的砷元素还原为砷化氢,以新银盐为显色液,用便携式测砷仪快速测定化妆品中砷元素。