DETERMINATION OF LEAD BY ELECTROTHERMAL VAPORIZATION MICROWAVE-INDUCED PLASMA-ATOMIC EMISSION-SPECTROMETRY AFTER FLOW-THROUGH ELECTROLYTIC DEPOSITION IN A GRAPHITE TUBE PACKED WITH RETICULATED VITREOUS CARBON

A simple method is described for the determination of lead in salt solutions by microwave-induced plasma atomic emission spectrometry (MIP-AES). Traces of Pb were preconcentrated electrochemically in a flow system incorporating a flow-through cell with a graphite tube packed with reticulated vitreous carbon serving as the working electrode. After washing the cell with water the tube was placed into the graphite furnace coupled to the capillary of an argon MIP operated in a surfatron. After the tube had been dried the plasma was ignited and the evaporation temperature was applied to the tube. The evaporated deposit was transported by argon gas into the plasma for excitation. A detection limit of 0.2 ng ml-1 of Pb in 1 ml of preconcentrated sample solution was achieved.