DIRECT DETERMINATION OF SELENIUM IN HUMAN BLOOD-PLASMA AND SEMINAL PLASMA BY GRAPHITE-FURNACE ATOMIC-ABSORPTION SPECTROPHOTOMETRY AND CLINICAL-APPLICATION

Direct determination of selenium (Se) in body fluids by graphite furna ce atomic absorption spectrophotometry (GFAAS) may suffer from problem s like severe background, matrix effects, preatomization losses, and s pectral interferences. In this study we evaluate critically the influe nce on the accuracy of the direct determination of Se in blood plasma and seminal plasma by GFAAS, and propose a simple, rapid, and accurate method, suitable for routine clinical analysis. The method for blood plasma is mainly based on studies by the use of matched matrix and a P d-Ni modifier, but for seminal plasma only a Pd modifier is required. The method developed was also applied to study the Se distribution in plasma protein fractions of patients with hepatocellular carcinoma. Th e Se in plasma of patients was significantly lower than that of the co ntrols. The distribution pattern of Se in blood plasma fractions of pa tients was also different from that of the controls.