Application of Pyrocatechol Violet to Spectrophotometric Analysis of Trace Cadmium Determination

A method is proposed by Cadmium-KI-Pyrocatechol Violet-DPB'S micelle for synergistic colour reaction.Cd²⁺-PV and KI,DPB from quaternary complex in a weak acid medium (pH=5～6).In the method of photometric,the maximum absorption wavelength (λ_max) is 710nm;the molar absorption coefficient(ε_max) is 1.6×10⁶L/(mol.cm).The method's sensibility is very high,and selectivity and repetition rate are very good.It can determine tracecadmium from glazed colour of porcelain dish that is dissolved in water.The method is simple and quick.The determined value of this method is identical with AAS.