用2,2'-吡啶基双（2-喹啉腙）分光光度法和荧光分光光度法测定锌和镉

Spectrophotometric and spectrofluorometric determination of zinc and cadmium with 2,2'-pyridil bis(2-quinolylhydrazone).

作者信息

West K J, Pflaum R T

机构信息

Department of Chemistry, University of Iowa, Iowa City, Iowa 52242, U.S.A.

出版信息

Talanta. 1986 Oct;33(10):807-10. doi: 10.1016/0039-9140(86)80198-9.

DOI:10.1016/0039-9140(86)80198-9

PMID:18964205

Abstract

The chelating ligand, 2,2'-pyridil bis(2-quinolylhydrazone), has been used for the spectrophotometric determination of zinc and cadmium in synthetic samples. The molar absorptivities of these metal complexes in 80% ethanol-water solution at pH 8 were found to be 4.60 x 10(4) and 5.10 x 10(4) 1.mole(-1).cm(-1) for zinc and cadmium respectively. Beer's law was obeyed for metal-ion concentrations between 1.0 x 10(-6) and 2.5 x 10(-5)M. The limits of detection were found to be 52 and 79 ng ml for zinc and cadmium respectively. The complexes fluoresced in 80% ethanol-water at pH 8 for zinc and at pH 10 for cadmium. The linear range for fluorescence as a function of metal-ion concentration was found to be 5 x 10(-7)-5 x 10(-6)M for both zinc and cadmium. Transition-metal ions interfere severely with both the spectrophotometric and fluorimetric determinations, and must be removed beforehand. An ion-exchange procedure is suitable for this.

摘要

螯合配体2,2'-吡啶基双(2-喹啉腙)已用于分光光度法测定合成样品中的锌和镉。在pH值为8的80%乙醇-水溶液中，这些金属配合物的摩尔吸光系数分别为锌4.60×10⁴和镉5.10×10⁴ 1·mol⁻¹·cm⁻¹。对于1.0×10⁻⁶至2.5×10⁻⁵M的金属离子浓度，符合比尔定律。锌和镉的检测限分别为52和79 ng/ml。这些配合物在pH值为8的80%乙醇-水中对锌发荧光，在pH值为10的条件下对镉发荧光。发现锌和镉的荧光强度与金属离子浓度的线性范围均为5×10⁻⁷ - 5×10⁻⁶M。过渡金属离子严重干扰分光光度法和荧光测定法，必须事先去除。离子交换法适用于此。