Immobilization of dithiooxamide in biopolymer and synthetic films for possible use in optical fibre copper probe

Abstract

Dithiooxamide (DTO), a metallochromogenic reagent, has been immobilized in a composite biopolymer matrix for the quantitative determination of CU(II) by an optical fibre method. The suitability of the biopolymer matrix for immobilization purposes has been determined from its stability in acid and basic media and absence of leaching of the immobilized DTO and its copper complex. Immobilization of DTO in poly(methyl)methacrylate (PMMA) alone shows characteristics comparable to that of the biopolymer matrix, while polyvinyl alcohol (PYA ), polyvinyl chloride (PVC) and Nafion^® membranes are found to be unsuitable. A linear response is obtained for Cu(II) concentrations between 1 to 5 ppm.