MICROCOLUMN PRECONCENTRATION AND GAS-CHROMATOGRAPHY MICROWAVE-INDUCEDPLASMA-ATOMIC EMISSION-SPECTROMETRY (GC-MIP-AES) FOR MERCURY SPECIATION IN WATERS

A novel method for the direct determination of mercury species at the ng l(-1) level in natural waters is described. Methyl-, ethyl- and ino rganic mercury are preconcentrated on a sulphhydryl cotton microcolumn incorporated in a flow injection system. Retained mercury species are then eluted with hydrochloric acid solution (3 mol/l) and subjected t o phenylation before determination by gas chromatography-microwave ind uced plasma-atomic emission spectrometry. Limits of detection for merc ury species are 10 ng l(-1) for methyl- and ethyl-mercury and 16 ng l( -1) for inorganic mercury based on processing 200 mi of sample. Applic ation of the methodology to waters of the Manchester Ship Canal reveal ed elevated levels of methylmercury and inorganic mercury.