SPECIATION AND SIMULTANEOUS DETERMINATION OF MERCURY SPECIES IN DOLPHIN LIVER BY LIQUID-CHROMATOGRAPHY WITH ONLINE COLD VAPOR ATOMIC-ABSORPTION SPECTROMETRY

An interface for coupling liquid chromatography with atomic absorption spectrometry is described and fully evaluated. Inorganic, methyl and ethyl mercury are separated as cysteinato complexes by isocratic eluti on on a reversed-phase column. Protein bound mercury is released from dolphin liver homogenate by acid hydrolysis. Inorganic and methyl merc ury are simultaneously determined by direct on-column injection of liv er hydrolysate previously subjected to a simple centrifugation step. N o sample cleanup, solvent extraction or chemical derivatization step i s required. Detection limits are in the order of 200 ng/g of tissue. T he method is highly selective for Hg species: no spurious peak was obs erved even with complex samples such as liver hydrolysate. A sampling rate of 12 samples/h was achieved.