Solid phase extraction of trace amounts of zinc and cadmium ions using perlite as a supper sorbent

A novel method using a packed column with perlite as a new sorbent has been developed for preconcentration of trace amounts of zinc and cadmium prior to their determination by flame atomic absorption spectrometry. Several factors that may be affected on the solid phase extraction (SPE) process, such as pH, sample volume, flow rate, volume and concentration of eluent were studied and optimized. Linearity was maintained between 0.001–0.1 µg mL−1 for zinc, and 0.001–0.3 µg mL−1 for cadmium. Detection limits based on 3Sb for zinc and cadmium were 1.8 and 1.6 ng mL−1, respectively. The relative standard deviations of eight replicate measurements of 0.02 µg mL−1 of zinc and 0.05 µg mL−1 of cadmium ions were 2.1% and 1.8%, respectively. Finally, the developed method was successfully applied to extraction and determination of the zinc and cadmium ions in the water and food samples and satisfactory results were obtained