Fast and simple extraction of pesticide residues in selected fruits and vegetables using tetrafluoroethane and toluene followed by ultrahigh-performance liquid chromatography/tandem mass spectrometry

An extraction and analytical method for the determination of pesticide residues in fruits and vegetables has been developed. The method includes extraction with a pressurised liquid solvent containing a mixture of 1,1,1,2-tetrafluoroethane and toluene, and identification/quantification of pesticides using ultra-high-performance liquid chromatography coupled to tandem mass spectrometry (UPLC/MS/MS). Validation studies were carried out to evaluate the performance of the method for the determination of 71 different pesticides and metabolites in tomato, cucumber, pepper, spinach, zucchini, grape, cherry, peach and apricot. Matrix-matched calibration curves were applied and correlation coefficients (r(2)) came out to be greater than 0.99. Limit of quantification (LOQ) values of the active substances were found to be lower than the maximum residue limits (MRL) according to regulations in Turkey. The recovery values were found to be between 70% and 120% with relative standard deviations less than 20%. Based on these results, the proposed method is fast, cheaper, rugged and gives quantitative results with no additional clean-up steps. (C) 2012 Elsevier Ltd. All rights reserved.