Determination of ultra trace arsenic species in water samples by hydride generation atomic absorption spectrometry after cloud point extraction
Cloud point extraction (CPE) methodology has successfully been employed for the preconcentration of ultra-trace arsenic species in aqueous samples prior to hydride generation atomic absorption spectrometry (HGAAS). As(III) has formed an ion-pairing complex with Pyronine B in presence of sodium dodecyl sulfate (SDS) at pH 10.0 and extracted into the non-ionic surfactant, polyethylene glycol tert-octylphenyl ether (Triton X-114). After phase separation, the surfactant-rich phase was diluted with 2mL of 1M HCl and 0.5mL of 3.0% (w/v) Antifoam A. Under the optimized conditions, a preconcentration factor of 60 and a detection limit of 0.008?gL-1 with a correlation coefficient of 0.9918 was obtained with a calibration curve in the range of 0.03-4.00?gL-1. The proposed preconcentration procedure was successfully applied to the determination of As(III) ions in certified standard water samples (TMDA-53.3 and NIST 1643e, a low level fortified standard for trace elements) and some real samples including natural drinking water and tap water samples. © 2011 Elsevier B.V.