DETERMINATION OF TOTAL MERCURY IN BIOLOGICAL TISSUES BY FLOW-INJECTION COLD VAPOR GENERATION ATOMIC-ABSORPTION SPECTROMETRY FOLLOWING TETRAMETHYLAMMONIUM HYDROXIDE DIGESTION

A simple, rapid and reliable method was developed for the determinatio n of total mercury in biological samples. Samples were solubilized usi ng tetramethylammonium hydroxide (TMAH), The organically bound mercury was cleaved and converted to inorganic mercury by on-line addition of KMnO4. The decomposed mercury together with inorganic mercury origina lly present in samples was determined by flow injection cold vapour at omic absorption spectrometry after reduction to elemental mercury vapo ur using NaBH4, A sample throughput of 100 measurements per hour was a chieved after a 30 min dissolution with TMAH, The relative standard de viation for 20 mu g l(-1) Hg was 1.3% (n = 11) and the limit of detect ion was 0.1 mu g l(-1) (30). The proposed method was validated by the analysis of a suite of certified marine biological reference materials , DORM-2 (dogfish muscle), DOLT-2 (dogfish liver) and TORT-2 (lobster hepatopancreas), with calibration against simple Hg-II standards.