Catalytic Kinetic Spectrometric determination of trace Cr(VI) with Cr(VI)-Crystal Violet-Hydrogen Peroxide system

It was based on the chromium(Ⅵ) which could catalyze the redox reaction between H2O2 and Crystal Violet in H2SO4 aqueous solution medium at 75 ℃.The absorbance difference(△A) between catalytic reaction and non-catalytic reaction was linear with the concentration of chromium(Ⅵ) in a certain range.On optimum conditions,calibration curve was linear in the range of 0~96 μg·mL-1,with the detection limit as low as 6.91 μg·mL-1(regression coefficient was 0.998 5).The regression equation was △A = 0.0033 + 0.1401C(μg/25mL).The method was simple and selective.It has been applied satisfactorily to the determination of chromium(Ⅵ) in wastewater samples.