Spectrophotometric determination of cerium by decoloring didromocarboxyar senazo

In this paper,the decoloring of didromocarboxysenazo oxidized by cerium(Ⅳ) in sulfuric acid has been studied.The decrease in absorbance is directly proportional to the amount of cerium.Under the reaction temperature of 25℃,The maxium absorption is at 530nm,the detection limit was 1.66×10~(-6) μg/mL and the regressive eqution is :ΔA=0.1646C_(Ce(Ⅳ))(μg/mL)-0.0194 and the liner range of the determination was 0～8.5 μg/mL.The method has been used for the determination of cerium in hair with satisfactory results.