采用分光光度法测定中国市售黄金饰品中六价铬的含量。采取四分法均匀取样,样品以碱性提取液浸出。浸出液中的铬(Ⅵ)在微酸性条件下与二苯碳酰二肼试剂反应生成紫红色络合物,于波长540 nm处测量其吸光度。六价铬的质量浓度在0.5 mg·L-1以内与其吸光度呈线性关系,检出限(3s)为0.001 mg·L-1。加标回收率在98.0%~100%之间,对六价铬质量浓度分别为0.05,0.10 mg·L-1的模拟样品溶液,分别测定11次,测定值的相对标准偏差分别为0.37%,0.27%。

Spectrophotometry was applied to the determination of chromium(Ⅵ) in golden adornments on domestic market. Sampling by quartering was adopted. The sample was extracted with an alkaline extractant, and Cr(Ⅵ) in the extract was reacted with diphenyl carbazide in a weakly acidic medium to form a violet complex, the absorbance of which was measured at 540 nm. Linear relationship between values of absorbance and mass concentration of chromium(Ⅵ) was obtained in the range within 0.5 mg·L-1, with detection limit (3s) of 0.001 mg·L-1. Values of recovery found by standard addition method were in the range of 98.0%-100%. Precision of the method was tested at concentration levels of 0.05, 0.10 mg·L-1 of Cr(Ⅵ) in simulated sample solution for 11 determinations, values of RSD′s found were 0.37%,0.27% respectively.