Radiochemical neutron activation analysis of Fe, Co, Zn, Sb and Se in biomedical and environmental samples.

A radiochemical neutron activation method has been developed for the simultaneous determination of Fe, Co, Zn, Sb and Se levels in cancerous breast tissue, milk samples and fugitive cement dust particulates. Various Standard Reference Materials from NIST, USA (Bovine Liver 1577a, Milk Powder 1549, Coal Fly Ash 1633a and Urban Particulate Matter 1648), IAEA Vienna (Animal Muscle H-4, Milk powder A-11 and Soil-5) and NIES Japan (Pond Sediment) were also analysed for quality control. Samples together with standards were irradiated at a thermal neutron fluence of 10(13) ncm-2s-1 for 2 weeks. After dissolution/fusion together with carriers, the Fe was first separated by extracting with diethyl ether followed by extraction with cupferron in chloroform. From the aqueous phase Co and Zn were extracted using alpha-nitroso-beta-naphthol in chloroform and 2-thenoyltrifluoroacetone in isobutylmethyl ketone, respectively. From another aliquot, Se was first complexed with o-phenylenediamine and extracted in benzene. Later Sb was extracted using KI and 4-(2-pyridylazo)-resorcinol (PAR) in benzene. The method yields reasonably accurate data for monitoring of trace elements in biomedical and environmental specimens.