Development and validation of modified QuEChERS method coupled with GC-MS/MS for 123 pesticide residues in food

Abstract

In this study, a gas chromatography-tandem mass spectrometry (GC-MS/MS) instrument, which has been widely used in recent years and has high separation power, selectivity and ability to identify pesticides has been used. It is aimed that the main criterion of this analytical method, in which the QuEChERS methodology is used, is applicable to fast, easy, cheap, environmentally friendly and different matrices. At the same time with this method, 123 pesticide residues and their degradation products were quantitatively assayed by GC-MS/MS as well as method validations in tomatoe, lemon, lettuce, almonds, raisins, honey, green pepper, milk and flour. Tomatoe was selected as potential reference matrixes for the target. The steps of concentration and solvent exchange were performed in the resultant extracts for the purpose of improving analytical performance in terms of recovery, precision, linearity, of reducing the amount of co-extracts. Multiple reaction monitoring (MRM) was used to identify and quantify the pesticides. The samples were extracted with 1% acetic acid in acetonitrile, anhydrous magnesium acetate, anhydrous magnesium sulfate and clearing agent. For all pesticides, good linear calibrations with coefficients (R2) ≥0.99 for nearly all of the analytes were obtained.  Limit of quantitation of most of the pesticides were in the range of 5-10 ng/g, and recovery of the method validation accuracy parameter was done at two different concentrations 10 ng/g and 50 ng/g were 88.6 - 99.7% and CV 1.60 – 14.0%