铁（Ⅲ）－α，α′－联吡啶－钴（Ⅱ）光还原体系的研究及其在分析中的应用

Photoreduction of Fe(Ⅲ)-Dipy-Co(Ⅱ)Complexesand Its Applications in Analysis

α，α’－联吡啶（Ｄｉｐｙ）可与Ｆｅ（Ⅲ）生成无色的配合物Ｆｅ（ｄｉｐｙ）３３＋，在散射光照下，上述配合物在水溶液中能发生光还原反应，在ｐＨ＝４．０的ＨＡｃ－ＮａＡｃ介质中，在避光条件下钴对无色的Ｆｅ（Ⅲ）－联吡啶配合物还原成红色的Ｆｅ（Ⅱ）－联吡啶配合物有较强的催化作用。据此建立了微量钴的光度分析方法，在０～１．０μｇＣｏ／ｍｌ范围内与吸光度成良好的线性关系，用所拟定的方法对维生素Ｂ１２及分子筛中的钴进行了测定，结果令人满意，并对反应机理作了初步探讨。

A new catalytic Kinetic system for the determination of trace cobalt ho been developed with spectrophotometry.As cabalt(Ⅱ)is present,colourless Fe(Ⅲ)-dipy complex can be reduced in HAc-NaAc medium(pH=4. 0) with the result of colour Fe(Ⅱ)-dipy complex when sitin the fork.Beer's law is obeyed within a concenration range of 0～10μg/10ml for Co(Ⅱ).Thismethod has been applied to the determination of trace amounts of cobalt in the samples with satisfactory results.