SPECTROPHOTOMETRIC STUDY OF THE COLOR REACTION BETWEEN NEW REAGENT o-METHYLBENZENEDIAZOAMINOAZOBENZENE AND THALLI UM(III)

In a borate buffer of pH 10.3,and in the presence of OP,a dark reddish colored coordination complex was formed between Zn(Ⅱ) and the color reagent HBDAAB in the mole ratio of(Zn∶R) 1∶2.Absorption maxima of the complex was found at the wavelength of 530 nm,where the molar absorptivity was found to be 1.65×10~5L·mol~(-1)·cm~(-1).Beer′s law was kept in the concentration range of 0-40 μg of Zn(Ⅱ) per 25 mL of solution.The proposed method has been applied to the analysis of several kinds of samples(eg.aluminum alloy,grain,human hair,water and etc.) for their zinc contents,giving RSD′s less than 3.2% and recoveries in the range of 97.5%-105.0%.