Екстракційно-фотометричне визначення хрому (VI) з брильянтовим зеленим

Abstract

Complexation and solvent extraction of chroшium(VI) with chloride ions and brilliant green (BG) have been examined. The influence of acid concentration and concentration of LiCl, NaCl, KCl, NH4Cl, MgCl2, CaCl2, SrC12, AlClз dye concentration and nature of solvent on the extraction of ion associates (IA) has been studied. The optimal condition forte IA formation and extraction is 10-4 - 10-5 М HCl, 6 - 7.8. М LiCl and (0.75 - 1.0) 10-з М BG, respectively. Beer's law was found the bе valid within the rang 0.2 - 18 mg of chromium(VI) per 5 cm3 of the aqueous phase. The molar absorption, while extracting bу different extractant, reach value Е640-650 = (7,16 - 2,76)х105. An ion-selective, membrane, based on IA of chromium(VI) with BG in dioctyl phthalate plasticizered PVC matrix, is suggested which is applicaЫe to determination of chromium(VI) over а concentration range of 10-2 - 10-5 М. А new procedure for extraction-photometric determination of chromium(VI) in waste waters has been developed.