Spectrophotometric determination of chromium ores, steels and pure nickel samples using phenothiazines

摘要

A new, simple,and sensitive method has been developed for the spectrophotometric determination of Cr~(VI) based on its reaction with chlorpromazine-HCl (CPH) to give a red product. Under the optimum conditions, the linear range of the calibration graph was 0.00-0.33 #mu#g mL~(-1) of Cr~(VI). The molar absorptivity and the detection limit were 3.28 X 10~4 dm~3 mol~(-1) cm~(-1) and 0.003 #mu#g mL~(-1) of Cr~(VI), respectively. Analyses of certified ores, steels, and pure nickel samples gave results in excellent agreement with the nominal values and with relative standard deviations of <= 1.5%.