FLOW-INJECTION ANALYSIS OF COPPER DIETHYLDITHIOCARBAMATE IN HIGH-RESISTANCE TOLUENE MEDIA USING A MICROELECTRODE DETECTOR

Flow injection (FI) analysis of copper as the copper diethylthiocarbam ate complex (Cu(Et(2)dtc)(2)) has been performed in a high resistance toluene carrier stream. The method is based on the oxidation of the co pper complex at a platinum microelectrode fabricated to fit a Metrohm wall-jet flow cell. Electrodes of sizes 5 to 25 mu m radii were tested in toluene-based carriers containing either 0.03 M tetrahexylammonium perchlorate (Hex(4)NClO(4)) or 35% acetonitrile. Detection limits (3: 1 signal to noise ratio) in the range 1 x 10(-7) M (5 mu m radius elec trode) to 5 x 10(-8) M (25 mu m radius electrode) were achieved, which are comparable to detection limits reported in lower resistance media under similar conditions. The system was applied to the analysis of c opper in water samples after extraction of the metal as its diethyldit hiocarbamate into toluene and good agreement was found with data obtai ned by other voltammetric methods.