Synthesis of Chelating Agent Free-Solid Phase Extractor (CAF-SPE) Based on New SiO2/Al2O3/SnO2 Ternary Oxide and Application for Online Preconcentration of Pb2+ Coupled with FAAS

A new online solid phase preconcentration method using the new SiO2/Al2O3/SnO2 ternary oxide (designated as SiAlSn) as chelating agent free-solid phase extractor (CAF-SPE) coupled to flame atomic absorption spectrometry (FAAS) for Pb2+ determination at trace levels in different kind of samples is proposed. The solid adsorbent has been characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron miscroscopy (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray fluorescence spectroscopy (XRF) and textural data. The method involves the preconcentration using time-based sampling of Pb2+ solution at pH 4.3 through 100.0 mg of packed adsorbed into a mini-column under flow rate of 4.0 mL min-1 during 5 min. The elution step was accomplished by using 1.0 mol L-1 HCl. A wide range of analytical curve (5.0-400.0 µg L-1), high enrichment factor (40.5), low consumption index (0.5 mL) and low limits of quantification and detection, 5.0 and 1.5 µg L-1, respectively, were obtained with the developed method. Practical application of method was tested on water samples, chocolate powder, Ginkgo biloba and sedimen t (certified reference material). On the basis of the results, the SiAlSn can be considered an effective adsorbent belonging to the class of CAF-SPE for Pb2+ determination from different matrices.
Source: Journal of the Brazilian Chemical Society - Category: Chemistry Source Type: research