ANALYTE PRECONCENTRATION AND SEPARATION FROM SMALL VOLUMES BY ELECTRODEPOSITION FOR ELECTROTHERMAL ATOMIC-ABSORPTION SPECTROSCOPY

Electrodeposition of Pb from 50 mul volumes of 0.1 M KCl solution was studied by electrolysis at uncontrolled potentials of 4.0-6.0 V on a p yrolytic graphite platform cathode. Deposition efficiency was evaluate d as a function of time by ASV measurements on aliquots of the electro lysed solution. Quantitative separation of the analyte from the matrix was achieved in a relatively short time, aided by convective stirring of the sample achieved through ps evolution. Thus, the feasibility of rapid electrodeposition directly in a pyrolytic graphite-coated furna ce has been demonstrated, allowing construction of an automated electr odeposition-electrothermal atomic absorption spectroscopic system.