Microdetermination of copper and cobalt in biological materials

Abstract

Copper and cobalt can be estimated in a single digest (sulfo-nitro-perchloric) of biological materials using the method of Eden and Green (1940) and the method of Saltzman and Kenan (1957), respectively applied on adequate aliquots. The method gives recoveries of 93.2% for cobalt and 94.8% for copper in the absence of initial organic material; and of 97.5% and 101.8% respectively in the presence of appreciable quantities of dry liver tissue. The results obtained recommend it as a good technique. Apparently there is no interference from other elements. In tests of reproducibility, values of 35.61 ± 0.56 ppm for copper and 0.394 ± 0.006 ppm for cobalt indicate good reproducibility in both cases. In tests for contamination, optical density readings were 0.029 for copper and 0,000 for cobalt.