PRECONCENTRATION AND ATOMIC-ABSORPTION DETERMINATION OF COPPER TRACESIN WATERS BY ONLINE ADSORPTION-ELUTION ON AN ACTIVATED CARBON MINICOLUMN

A continuous preconcentration method for the determination of trace co pper in waters was developed. Ammonium pyrrolidinedithiocarbamate is u sed to form a chelate which is adsorbed on an activated carbon minicol umn and desorbed with 200 mul of methyl isobutyl ketone. The organic e xtract is driven by a water stream to an atomic absorption spectromete r. By using a time-based technique equivalent to from 1.5 to 4.5 ml of sample, preconcentration factors between 35 and 100, respectively, ar e achieved. The flow system is quite simple and rapid, and provides hi ghly precise results (RSD 1.8-3.5%). The results obtained in the deter mination of copper in waters show the usefulness of the proposed metho d.