巯基棉富集─5－Br－DMPAP光度法测定矿石中痕量铟

Spectrophotometric Determination of Trace lndium in Ores with 5-Br-DMPAP after Separation with Sulfhydrylated Cotton

本文提出了测定痕量铟的新方法，研究了在含氧有机溶剂及氯化十六烷基吡啶（ＣＰＣ）存在下，２－［（５－溴－２－吡啶）偶氮］－５－二甲氨基苯酚（５－Ｂｒ－ＤＭＰＡＰ）与铟的显色反应条件。在ｐＨ６．５乙酸－乙酸钠缓冲体系中，铟与５－Ｂｒ－ＤＭＰＡＰ形成稳定的红色配合物，其波长为５６０ｎｍ，表观摩尔吸光系数为８．６１×１０￣４，线性范围０～６０μｇ／２５ｍｌ铟符合比尔定律，对多种常见共有离子的影响进行了研究，经巯基棉富集分高，用于岩石中铟的测定，结果满意。

A new method for the spectrophotometric determination of trace indium with 5-Br-DMP-AP is described．In a medium of HAc-NaAc（pH=6．5 ） in the presence of CPC,5-Br-DMPAP reacts with indium to form a stable red eomplex with maxium absorption at 560nm.The apparent molar ab-sorptivity is 8·61×10~4.Beer′s law is obeyed in the range of 0-60μg per 25ml.The indium is separatedfrom the matrix by sulfhydrylated cotton adsorption to eliminate some interferences．The method hasbeen used for the determination of in dium in ores with satisfactory results.