Pervaporation as a separation technique for direct determination of volatile selenium species by atomic fluorescence spectrometry

This paper reports for the first time a suitable way to determine methylate d selenium compounds using the new approach of pervaporation coupled to ato mic fluorescence spectrometry (PV-AFS). The method developed allows direct extraction, separation, preconcentration and determination of dimethylselenium (DMSe) and dimethyldiselenium (DMDSe ) from slurry samples. Under the optimum conditions, the detection limits ( LODs) were found to be 0.66 ng and 0.39 ng for DMSe and DMDSe, respectively , the precision being about 6-9% for 10 ng mL(-1) as selenium concentration . The linearity ranges were from the LOD to 0.7 mug mL(-1) for DMSe and fro m the LOD to 0.4 mug mL(-1) for DMDSe las Se). The pervaporation efficienci es were 55 +/- 1% and 85 +/- 5 % for DMSe and DMDSe, respectively. The prop osed method was successfully applied to determine methylated selenium speci es in sewage sludge, garlic and oyster samples. The concentrations found we re from 0.07 to 1.42 mug g(-1). As no certified reference materials are available for these analytes, valid ation was carried out by recovery studies in these matrices, and the result s showed that the proposed method performed satisfactorily.