碘化物-碱性呫吨染料-聚乙烯醇体系高灵敏分光光度法测定铊

Highly Sensitive Spectrophotometric Determination of Trace Amounts of Thallium (Ⅲ) With the Iodide-Basic Xanthene Dye-Polyvinyl Alcohol System

研究了在聚乙烯醇存在下,铊(Ⅲ)与碘化钾和罗丹明B,罗丹明6G、乙基罗丹明B、丁基罗丹明B碱性呫吨染料形成离子缔合物的显色反应,讨论了铊(Ⅲ)-碘化钾-罗丹明B-聚乙烯醇体系的反应条件和分析特性,ε_(585)=7.03×10~5L·mol^(-1)·cm^(-1),此法可用于水样中微量铊的测定。

The colour reaction of the thallium(Ⅱ) with iodide and basic xanthene dyes such as rhodamine Bt rhodamine 6G,ethylrhodamine B and butylrhodamine B in the presence of PVA in aqueous solution was investigated. The reaction conditions and analytical characteristics of the system of thallium(Ⅱ)-iodide-rhodamine B-PVA were studied in detail. This colour reaction has a very high sensitivity (Ⅲ535 = 7. 03 × 105 L· mol-1·cm-1) and can be applied to the spectrophotometric determination of trace amounts of thallium in water.