RAPID-DETERMINATION OF COPPER, NICKEL, LEAD AND CADMIUM IN SMALL SAMPLES OF ESTUARINE AND COASTAL WATERS BY LIQUID-LIQUID-EXTRACTION AND ELECTROTHERMAL ATOMIC-ABSORPTION SPECTROMETRY

A rapid liquid/liquid extraction of 1.25-ml samples is used with graphite-furnace atomic absorption spectrometry for the determination of dissolved trace metals in saline waters. The metals are chelated with ammonium pyrrolidine dithiocarbamate and extracted into 1,1,1-trichloroethane; 20-40 μl of extract is injected into the furnace. Sample manipulation and overall time are greatly decreased compared to other similar large-scale extraction methods; all the chemical steps are done in the sample cups of an auto-sampler for graphite-furnace a.a.s. Detection limits (Cu 0.3 μg l-1, Cd 0.02 μg l-1, Pb 0.7 μg l-1, Ni 0.5 μg l-1 are low enough for applications in routine monitoring of filterable trace metal concentrations in coastal and estuarine waters to check for compliance with Environmental Quality Standards that apply in the European Community. © 1987.