镉(Ⅱ)苯肼硫代羰偶氮苯-吐温-20体系的分光光度研究

A Research on Spectrophotometry of Cadmium-1.5 Diphenylthiocarbazone-Tween-20 System

研究了在Ｔｗｅｅｎ－２０存在下，苯肼硫代羰偶氮苯（ＨＤ２）与镉（Ⅱ）显色体系，在ｐＨ６．０的乙酸—乙酸钠介质中，显色反应灵敏度较高，络合物最大吸收峰位于５１０ｎｍ处，其摩尔吸光系数为９．２×１０４Ｌ·ｍｏｌ－１·ｃｍ－１．镉含量在０．０４～１５μｇ／２５ｍＬ符合比尔定律，该体系可用于水中微量镉的测定。

It is studied that cadmium (Ⅱ) reacts with 1.5-diphenylthiocarbazone (HD 2) to form a red complex in the presence of Tween-20 at pH6.0 HAC-NaAc buffer solution with high sensitivity of reaction. The maximum absorptivity of the complex locates in 510 nm, with molar absorptivity factor being 9.2×10 4 L·mol -1 . cm -1 . The content of cadmium is in the range of 0.04￣15 μg/25mL, therefrom, in conformity to Beer′s law. This system can be applied to the determination of cadmium of least content in water, then the result will be satisfactory.