Study of bond Elut® Plexa™ PCX cation exchange resin in flow injection column preconcentration system for metal determination by flame atomic absorption spectrometry

A simple and sensitive on-line solid-phase extraction methodology for preconcentration and determination of trace amounts of Cd(II), Pd(II) and Cu(II) in natural water samples has been developed using the strong cation exchange capability of Bond Elut® Plexa™ PCX polymer resin. Plexa PCX is a mixed-mode sorbent, commercially available in a cartridge format and as far as we know, there is no application into the field of metal determination. The analytes were retained on the resin, eluted with 1 mol L−1 hydrochloric acid and subsequently directed to FAAS for quantification. The influence of chemical and flow variables which affect the performance of the system have been studied, providing the appropriate conditions for the analysis of real samples. For preconcentration time of 90 s, an enrichment factor of 90, 95 and 95 and a detection limit (3s) of 0.1, 1.8 and 0.5 μg L−1 for Cd(II), Pb(II) and Cu(II), respectively were obtained along with a sampling frequency of 30 h−1. The accuracy of the proposed method was evaluated by analyzing certified reference materials. This procedure was successfully applied for metal determination in environmental and biological samples.