Fully automatic on-line separation preconcentration system for electrothermal atomic absorption spectrometry: Determination of cadmium and lead in sea-water.

An automatic separation preconcentration system coupled to an electrothermal (graphite furnace) atomic absorption spectrometer is described. The preconcentration step is performed on a chelating resin microcolumn (Chelex-100) placed in the injection tip of the autosampler, A time based manifold with two- and three-may solenoid valves commanded by an eight channel microcomputer programmable controller is used for column conditioning, preconcentration and mashing steps; no manual operations are involved, Elution is performed by the programmable graphite furnace autosampler and achieved in only one step, Operations involving complete and partial injection of the eluate into the graphite furnace are also discussed. The system was applied to the determination of Cd and Ph in near shore sea-mater from Patagonia, Argentina. Detection limits of I and 8 ng l(-1) mere obtained for Cd and Pb respectively, Analysis of a certified reference material (CASS-3) showed good agreement with the certified values.