RADIOCHEMICAL DETERMINATION OF CHROMIUM IN BIOLOGICAL TISSUES BY ION-EXCHANGE

A simple ion exchange procedure has been developed for the separation of chromium from the other chemical elements in biological tissues. This procedure combined with neutron activation analysis has been applied successfully to the determination of chromium in a reference biological material. The precision was ±11%, the accuracy 3% and the sensitivity found was 10 ng with only 20 hrs irradiation at 2.8·1013 n·cm−2·sec−1 flux The main steps of the procedure are: wetdigestion of the irradiated tissue, oxidation to chromium (VI), fixation onto an anion resin in sulfate form, washing of the resin with 1N H2SO4, collection of chromium by reductive elution for counting and finally determination of the chemical yield by reactivation.