THE ACCUMULATION AND DISTRIBUTION OF TRACE-METALS IN SOME LOCALIZED MARINE SPECIES

Trace elements, such as As, Co, Cr, Hg, Sb, and Zn, were determined by neutron activation analysis (NAA), whereas Cd, Cu, and Pb were determ ined by graphite furnace atomic absorption spectroscopy (GFAAS) in cla m, crab, prawn, swamp cerith, and mussel samples after digestion by mi crowave heating under controlled conditions before eluting the solutio ns through a column of a chelating resin, Chelex-100. The standard use d in the determination of percentage volatile elements retained by mic rowave digestion and also in the activation process was Lobster Hepato pancreas TORT-I, whereas known mixed standards were prepared from nitr ate salts to determine the efficiency of the separation procedure at a controlled pH. Mercury and lead detected in crabs exceeded the maximu m permissible level. Some species also showed a high affinity toward c ertain elements, and their levels of accumulation in the tissues of th ese species corresponded with the concentration of these elements in s ediments, especially at sites in the vicinity of an industrial zone.