Coupling of the RP C18 preconcentration HPLC-UV-PCO system with atomic fluorescence detection for the determination of methylmercury in sediment and biological tissue

An HPLC-UV-PCO-system (High Performance Liquid Chromatography, Ultraviolet, Post-Column Oxidation) was coupled with a cold vapor atomic fluorescence spectrometer (CVAFS) for separation and determination of mersalyl acid, methyl-, ethyl-, phenyl- and inorganic mercury. The mercury compounds were preseparated from the matrix using water vapor distillation, The compounds in the distillate were enriched as pyrrolidinedithiocarbamate complexes on an RP C18 preconcentration column and measured with the newly developed CVAFS detection system. The detection limit for methylmercury was 8 pg absolute for the enrichment of 5 mL distillate. The sensitivity of the HPLC-UV-PCO-CVAFS was improved by a factor of ten in comparison to a previously developed coupling technique with a cold vapor atomic absorption spectrometer (CVAAS). For methylmercury determination the detection limit for a 0.5 g sample was calculated to be 0.015 mu g/kg.