1,2,4,6-Tetraphenylpyridinium perchlorate as a reagent for ion-association complex formation and its use for the spectrophotometric determination of thallium

Abstract

The synthesis, characteristics and applications of 1,2,4,6-tetraphenylpyridinium perchlorate (TPPP) as a reagent for the formation of ion-association complexes is described. This reagent forms a 1 : 1 complex with TlC1,-(h,,,, 310 nm, molar absorptivity 3.14 x lo4 1 mol-1 cm-1) that is slightly soluble in water and can be extracted with isopentyl acetate with an extraction efficiency of 97.9%. The TlC1,--TPP+ complex obtained is useful for the spectrophotometric determination of thallium in the concentration range 0.05-0.8 p.p.m., and the method is applicable to the determination of thallium in sphalerites and zinc concentrates.