title: Multivariate optimization of a solid phase microextraction-headspace procedure for the determination of benzene, toluene, ethylbenzene and xylenes in effluent samples from a waste treatment plant.
abstract: A method based on solid-phase microextraction (SPME) and gas chromatography with flame ionization detection (GC-FID) has been optimized for the determination of benzene, toluene, ethylbenzene and xylenes (BTEX) in water released from a waste treatment plant. The extraction step was optimized using fractional factorial and central composite designs including the following experimental factors: saline concentration; extraction time; desorption time; agitation velocity; headspace volume. A multiple function was used to describe the experimental conditions for simultaneous extraction of the compounds. The procedure, based on direct SPME at 50 degrees C, using a polydimethylsiloxane fiber, showed good linearity (r>0.997 over a concentration range 2-200 microg L(-1)) and repeatability (relative standard deviation (RSD)<4.23%) for all compounds, with limits of detection ranging from 0.05 to 0.28 microg L(-1), and limits of quantification ranging from 0.14 to 0.84 microg L(-1). Concentrations of the target compounds in these samples were between 145.8 and 1891 microg L(-1).
authors.affiliation: Escola Agrotécnica Federal de São Cristóvão, 49100-000 São Cristóvão, SE, Brazil.
authors.forename: Alain
authors.initials: A
authors.lastname: Gaujac
authors.forename: Elissandro Soares
authors.initials: ES
authors.lastname: Emídio
authors.forename: Sandro
authors.initials: S
authors.lastname: Navickiene
authors.forename: Sérgio Luis Costa
authors.initials: SL
authors.lastname: Ferreira
authors.forename: Haroldo Silveira
authors.initials: HS
authors.lastname: Dórea
mesh_terms: D001554:Benzene / Q000032:analysis*; D001555:Benzene Derivatives / Q000032:analysis*; D002849:Chromatography, Gas / Q000379:methods*; D015999:Multivariate Analysis; D015203:Reproducibility of Results; D052617:Solid Phase Microextraction / Q000379:methods*; D014050:Toluene / Q000032:analysis*; D035501:Uncertainty; D014865:Waste Disposal, Fluid; D014874:Water Pollutants, Chemical / Q000032:analysis*; D014992:Xylenes / Q000032:analysis*
chemical_list: D001555:Benzene Derivatives; D014874:Water Pollutants, Chemical; D014992:Xylenes; D014050:Toluene; D001554:Benzene; C004912:ethylbenzene