DApBM-V(Ⅴ)-Mn(Ⅱ)-Tween-80体系光度法测定钒(V)

Spectrophotometric Method of DApBM-V(Ⅴ)-Mn(Ⅱ) -Tween-80 Determined Vanadium(Ⅴ)

在磷酸介质中，在Ｍｎ（Ⅱ）和Ｔｗｅｎ－８０存在下，ＤＡｐＢＭ与钒（Ⅴ）生成橙黄色化合物，产物至少可稳定３．５ｈ．最大吸收波长为４８５ｎｍ．摩尔吸光系数ε＝４．０１×１０５Ｌ·ｍｏｌ－１·ｃｍ－１和ε＝１．５７×１０５Ｌ·ｍｏｌ－１·ｃｍ－１．钒（Ⅴ）量在０．５～３．０μｇ／２５ｍｌ及３．０～１０．０μｇ／２５ｍｌ间符合比尔定律．该体系灵敏度高，选择性较好，用于中草药中痕量钒（Ⅴ）的测定。

In the presence of Mn(Ⅱ)and Tween-80,DApBM reacts with V(Ⅴ)to form a orange-yellow product in phosphoric acid medium. Maxium absorbance of the product is at 485nm with molar absorptivity of 4.01×10 5 L·mol -1 ·cm -1 and 1.57×10 5 L·mol -1 ·cm -1 . Beer's lawis obeyed in the range of 0.5～3.0μg/25ml and 3.0～10.0μg/25ml. The method was applied to determine V(Ⅴ)in Chinese hebral medicine,the results are obtained satisfactory.