SPECIATION OF METHYLMERCURY AND INORGANIC MERCURY IN BIOLOGICAL TISSUES USING ETHYLATION AND GAS-CHROMATOGRAPHY WITH FURNACE ATOMIZATION PLASMA EMISSION SPECTROMETRIC DETECTION

A sensitive and interference-free method for the quantification of ino rganic and methylmercury species in biological tissues is presented us ing purge-and-trap injection-GC-AES, Samples were solubilized with tet ramethylammonium hydroxide and the ionic species were purged from aque ous solution after ethylation with sodium tetraethylborate. The specie s were preconcentrated on Tenax-TA and thermally desorbed onto an isot hermal (90 degrees C) GC column packed with 15% OV-3 on Chromasorb W, The separated species were eluted in He to a FARES source for detectio n by AES at 253.6 nm, Absolute detection limits of 1 and 7 pg for inor ganic and methylmercury, respectively, can be obtained, corresponding to concentration LODs of 0.2 and 1.4 ng g(-1), respectively, in solid tissue samples. Precision of determination is better than 10% RSD, The accuracy of the technique was validated by the analysis of National R esearch Council of Canada CRMs DORM-2, DOLT-2 and TORT-2, certified fo r mercury species content.