Two-phase hollow fiber liquid phase microextraction for preconcentration of pyrethroid pesticides residues in some fruits and vegetable juices prior to gas chromatography/mass spectrometry

A sensitive and reliable extraction method based on two-phase hollow fiber liquid phase microextraction followed by gas chromatography-mass spectrometry has been developed for determination of three pyrethroid pesticides. The various parameters affecting the extraction efficiency were studied via rotatable-centered cube central composite design (CCD). The optimization results showed that speed of agitation, extraction time and ionic strength were significantly important in the extraction process. A response surface equation was derived, and the statistical parameters of the derived model were obtained as R-2 = 0.9862 and F = 142.46. The response surface plots revealed a separation optimum with 480 rpm speed agitation, extraction time of 41 min and NaCl concentration of 3% (w/v). Method detection limits were obtained in the range of 0.02-0.07 ng/mL, and limits of quantitation were between 0.08 and 0.10 ng/mL. The proposed method was successfully applied for the determination of pyrethroid pesticides in some fruits and vegetable juice samples and satisfactory results were obtained. (C) 2013 Elsevier Inc. All rights reserved.