【摘要】 研究了7-碘-8-羟基喹啉-5-磺酸（H2QSI）在乙醇存在下分光光度法测定钡（Ⅴ）的最佳条件。在乙醇存在下pH4的硫酸介质中,（H2QSI）与V（Ⅴ）形成了红棕色配合物,最大吸收位于506nm处,表观摩尔吸光系数εmax＝2.9×103L·mol-1·cm-1,有色配合物组成为V（Ⅴ）:（H2QSI）＝1:3。钒（Ⅴ）在0-14μg／25mL符合比耳定律、本法用于钢样中的测定,结果满意。H2QSI是光度分析中的一种显色剂,近年来,8-羟基喹啉类试剂用于钒（Ⅴ）的测定已有报道[1]:,H2QSI曾见用于稀土元素的光度测定[2],但用于钒（Ⅴ）的测定尚未见报道。本文研究了V（Ⅴ）与H2QSI的显色反应条件及组成,在pH4的乙醇介质中,V（Ⅴ）与H2QSI生成红棕色配合物ε506nm＝2.9×103L·mol-1·cm-1。本方法用于低碳合金钢中钒的测定,结果满意。更多还原

【Abstract】 The conditions optimised for the spectrophotometric determination of vanadium (V ) in the presence of alcohol using-7-iodine-8-hydroxyguinolin acid as color reagent were studied. Under the condition of pH4 of sulfuric acid and in the presence of alcohol,H2QSI reacts with V (V ) to form the red-brown complex, whose maxAnum absorption exhibits 506nm. Its apparent molar absorptivity εmax is 2. 9 ×103L. mol-1. cm-l,the composition of the complex V (V ): H2QSI being 1:3. T he Beer’s law is obeyed over the concentration of o- 14μg/25mL of vanadium’ The method has been used in the determination of vanadium in steel samples, and the results are satisfactory.更多还原