Multi-residue screening of endocrine disrupters chemicals in water samples by stir bar sorptive extraction-liquid desorption-capillary gas chromatography-mass spectrometry detection

The powerful capabilities of the stir bar sorptive extraction followed liquid desorption in combination with large volume injection and capillary gas chromatography coupled to mass spectrometry, were successfully applied to screen more than 60 endocrine disrupters chemicals, including herbicides, organochlorine and organophosphorous pesticides, polycyclic aromatic hydrocarbons, polychlorinated biphenyls, biocides, phthalates and alkylphenols in water samples at the ultra-trace level. During method development, it has been established that stir bars coated with 47 muL of polydimethylsiloxane, a standard equilibrium time of 60 min (750 rpm) at room temperature (20degreesC) and acetonitrile as back extraction solvent, promote good performance to monitor endocrine disrupters chemicals in water samples. Assays on 30 mL laboratory-spiked water samples having a minimum of 5% of methanol, allowed high sensitivity and remarkable reproducibility (<18.4%) for screening endocrine disrupters chemicals at the 0.10 mug/L level. The data obtained from the recovery yields shows that stir bar sorptive extraction followed liquid desorption could be described by the octanol-water partition coefficients (K-O/W), in which some of the deviations correspond to particular compounds where equilibrium conditions were not achieved. From calibration studies, excellent linear dynamic ranges were obtained for almost all endocrine disrupters chemicals from water samples at the ultra-trace level (0.025-0.400 mug/L). The present methodology is a cost-effective alternative for routine quality control analysis, showing to be easy, very sensitive and not much volume of water sample is required to screening endocrine disrupters chemicals in compliance with European Union directives on water quality. (C) 2004 Elsevier B.V. All rights reserved.