Spectrophotometric Determination of Chromium(Ⅵ) in Golden Adornments on Domestic Market

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.