Kinetic spectrophotometric determination of trace rutin based on oxidative discoloration of acid chrome blue K with hydrogen peroxide

Based on the catalytic effect of trace amount rutin on oxidation of acid chrome blue K(ACBK) by hydrogen peroxide in a 2 mmol/L sulphuric acid solution,a new kinetic spectrophotometric method for the determination of trace amount of rutin has been developed.The detection limit is 1.08 μg/L and the linear range of determination is 3.6～400 μg/L for rutin.The relative standard deviation for the determination of rutin at the concentration of 10.0 μg/25 mL is calculated to be 1.6%(n=11).The factors such as acidity,concentrations of reactants,reaction time,temperature,influence of coexisting ions on the reaction and the optimum reaction conditions of the reaction and some kinetic parameters are determined;the apparent activation energy of the reaction is 73.22 kJ/mol.Combined with solvent extraction separation,the method has been applied to the determination of rutin in sophorine and pharmaceutical preparations samples with the relative standard deviations of 1.0%～1.1% and the recoveries of 98.0%～101.7%.