The determination of trace amounts of cobalt and other metals in high-purity water by using ion-exchange membranes

Abstract

Microgram amounts of cobalt, chromium, copper, iron, nickel and zinc are concentrated on ion-exchange resin impregnated membranes from large volumes of reactor cooling waters. Atomic-absorption measurement on the acid-extracted membranes has permitted the determination of cobalt down to 0·01 µg l^–1 in water samples, with an analytical precision of ±12 per cent. at the 96 per cent. confidence limit, based on twelve replicate observations. Gamma-spectrometric measurement of the nuclide cobalt-60 present in the reactor cooling waters has enabled membrane efficiency to be determined; at cobalt levels of 0·01 and 0·1 µg l^–1, the efficiencies are shown to be 85 per cent. and greater than 99 per cent., respectively.