USING AN ULTRASONIC SLURRY SAMPLER WITH GRAPHITE-FURNACE AAS FOR THE DETERMINATION OF HEAVY-METALS IN SEDIMENTS

An ultrasonic slurry sampler was employed for the determination of heavy metals (Cu, Cr, Pb, Ni, Cd, and As) in two certified BCR sediments using graphite furnace atomic absorption spectrometry (GFAAS). The slurry was prepared in volumes larger than would be necessary to fit into the autosampler cups to enable the weighing of a larger quantity of solid material. However, after the slurry was prepared, the autosampler cups were used, which may have given rise to analytical errors. The results obtained using this method suggest that the determination of Cu, Cr, Ni, Cd, and As in sediments can be carried out very effectively. However, the results for the determination of Pb were too high (+ 20%) and no explanation for this discrepancy can as yet be advanced.