碱性染料吸光光度法测定贵金属的超高灵敏显色体系研究应用概况

Super-high Sensitive Chromogenic Systems for Precious Metals Determination by Basic Dye Photometry

碱性染料是光度法测定贵金属的一类灵敏显色剂,用这类试剂测定贵金属已有200多例显色体系,其中有50多例超高灵敏(ε>106L/mol.cm)显色体系。经过对这些体系的分析对比,认为取得超高灵敏显色体系的关键:(1)创造贵金属络阴离子与染料阳离子形成复杂的离子缔合物沉淀的条件;(2)设法使复杂的缔合物沉淀及其超额偕带的染料分子均匀地转入溶液以利测定。

Basic dyes are the sensitive chromogenic agents for precious metals determination by photometry. This paper analyzed about 200 kinds of this super-high sensitive chromogenic systems （ε 〉 10^6 L/mol. cm）. Through contrasting research it has been found out that the keys to get super-high sensitive chromogenic systems are that create suitable conditions for forming a complicated ionic association precipitate through precious metal＇s comlex anion with dye cation, and try transferring the complicated precipitate and above-quota companying dye molecules to the solution equably so that they are suitable for next-step determination.