萃取分光光度法测定水和硫酸中的硒

Extraction Spectfophotometric Determination of Selenium (Ⅳ)in Water and Sulphuric Acid

本文提出一种测定硒的分光光度法。在酸性介质中，四价硒氧化Ｉ－成为Ｉ＿３－，Ｉ￣３－和结晶紫形成的离子缔合物用二甲苯萃取，进行分光光度测定。硒的检出限是０．０５μｇ／ｍＬ。用磷酸和ＥＤＴＡ消除Ｆｅ（３＋）、Ｐｂ（２＋）、Ｈｇ（２＋）、Ｃｄ（２＋）多离子的干扰影响。本法可测定水和硫酸中四价硒。

A extraction spectrophotometric method for the determination of Selenium(Ⅳ)has been proposed, based on Se(Ⅳ) oaldation I-to I3 in a acid medium, then formation of the ion-association complex of I3 with Crystal Violet is extracted by Xylene. The detection limit is 0. 05μg/mL. By using Phosphoric acid medium and EDTA,the method eliminates interference from Fe3+ .Pb2+ .Hg2+ .Cd2+ and so on. The method can be used to determine Se(Ⅳ) in water and sulphuric acid samples.