The polarographic determination of tripolyphosphate ions and of tripolyphosphate and nitrilotriacetic acid in admixture

Abstract

Tripolyphosphate ions in amounts from 2 to 20 µmol are determined by measurements of the decrease in the height of the cadmium polarographic wave by using a trimetaphosphate buffer at pH 7·0. Up to 5 mol per cent. of orthophosphate or pyrophosphate and 50 per cent. of trimetaphosphate or tetrametaphosphate ions do not interfere. Tripolyphosphate and nitrilotriacetic acid in admixture can be determined by measuring the reduced height of the cadmium wave and the cadmium-nitrilotriacetic acid complex wave.