SPECIATION OF ELEMENTS IN LAKE-SEDIMENTS INVESTIGATED USING X-RAY-FLUORESCENCE AND INDUCTIVELY-COUPLED PLASMA-ATOMIC EMISSION-SPECTROMETRY

Radioisotope-excited energy-dispersive x-ray fluorescence (EDXRF) anal ysis and inductively coupled plasma atomic emission spectrometry (ICP- AES) mere used to investigate the speciation of elements in sediment s amples collected from a peat bog in Hungary. Lake and bog sediments ar e a mixture of allogenic material (clastic mineral particles resulting from erosion of the catchment soils or from dust) and authigenic comp onents (deposited directly from aquatic solution through biological up take or chemical sorption, biochemically precipitated carbonate minera ls, Fe and Mn oxides, oxyhydroxides, sulphides, sulphates, phosphates, etc.). After removing the authigenic fraction by wet digestion, eleme nt concentrations in the acid insoluble residue were determined by XRF and those in the authigenic part by ICP-AES. On the basis of chemical composition, the sediment sequence was divided into three zones refle cting different environmental regimes during sediment accumulation. Al logenic and authigenic species of elements provided relevant informati on on environmental processes which changed the soil and vegetation in NE Hungary during the early postglacial. (C) 1988 John Wiley & Sons, Ltd.