β修正分光光度法测定环境物质中痕量硒

β-CORRECTION SPECTROPHOTOMETRY FOR DETERMINATION OF TRACE SELENIUM IN ENVIRONMENTAL MATERIALS

在0．1mol／L盐酸介质中，Se（Ⅳ）与碘化物（Ⅰ-）和丁基罗丹明B（BRhB）反应生成蓝色缔合物．本文依据β修正分析理论研究环境物质中微量硒的测定，应用此原理，缔台产物中Se与BRhB组成比及其实际摩尔吸光系数（εp）均可简单、准确测定，结果分别是1：2；132×105L／mol·cm．实际样品测定结表明：相对标准偏差9％，加标回收率89.3～112％

In 0.10 mol/L hydrogen chloride the reaction of selenium (Ⅳ) with both potassium iodide and Butyl Rhodamine B (BRhB) leads to a blue complex. The β-correction principle is applied to the determination of trace amount of Se in environmental materials using the above reaction.The β-correction method can eliminate completely the influence of excess BRhB in its colored solution on the determination of real absorbance.The complex-ratio of Se to BWhB and the true mole absorptivity of chelate Se-BAnB-Ⅰ- are evaluated to be 1/2 and εp=1.32×105 L/mol·cm, respectively. The results show that the sensitivity precision andaccuracy by the β-correction method are all higher than those of the single wavelength method.The recovery is between 89.3 and 112% with s. d. of 9% for the analysis of several environmental materials.