Catalytic kinetic spectrophotometric determination of trace chromiumVI with sensitization effect of surfactant

A catalytic kinetic spectrophotometric method for the determination of trace CrⅥ has been developed.The method is based upon the catalytic effect of CrⅥ on the oxidation of fading reaction of methylene blue by hydrogen peroxide in weak acid medium.The sensitivity of reaction can increase about 5 times after the addition of CTMAB.The linear range of determination was 0.05-48.0 g/L,and the detection limit is 0.047g/L.The apparent activation energy of the reaction is found to be 71.1kJmol~(-1),and the rate constant is 1.1510~(-3)s~(-1).The method can be used for the determination of CrⅥ in water samples and steel samples.