Preconcentration of trace amounts of cadmium in aqueous samples on minicolumns packed with Chromosorb series gas chromatographic stationary phases and its determination by electrothermal atomic absorption spectrometry

The adsorption characteristics of five commercially available Chromosorb GC stationary phases towards Cd2+ and their application to the preconcentrati on and ETAAS determination of Cd2+ in several water samples were studied. T he experimental results indicated that although all of the five Chromosorb GC stationary phases Studied can retain Cd2+ quantitatively from aqueous so lutions at appropriate pH values without adding chelating reagent, Chromoso rb 105 displayed the highest adsorption capacity. A highly sensitive, simpl e methodology for preconcentration and ETAAS determination of trace amounts of cadmium in natural water Samples using a Chromosorb 105 packed minicolu mn is proposed. Conditions for quantitative and reproducible preconcentrati on, elution and subsequent ETAAS determination were established. The high r etention efficiency (>95%) for Cd2+ provides a sensitivity enhancement of 1 00-fold for a 200 mL sample volume with a detection limit of 6.2 ng L-1 (3 sigma).