Method development and optimisation for analysis of pesticide residues in biological matrices by modified QuEChERS and gas chromatography-triple quadrupole mass spectrometry

A rapid and precise modified QuEChERS method for extraction was developed for simultaneous quantitation of multi-class pesticide residues in human biological matrices, viz. blood, serum and urine. In the modified QuEChERS method, targeted analytes in biological sample were extracted using acidified solution of acetonitrile and ethyl acetate along with anhydrous MgSO4. The collected aqueous layer was evaporated and dispersive solid-phase extraction clean-up was performed. The pesticide residues were assessed using gas chromatography-tandem mass spectrometry with multiple reaction monitoring mode. The developed method was validated as per European Union SANTE/12682/2019 guidelines and the evaluated method validation parameters, viz. linearity, limit of detection, limit of quantitation, accuracy, %relative standard deviation and matrix effect were found to be satisfactory. The proposed method is easy, comprehensible and efficient for simultaneous analysis of diverse range of pesticide residues within similar class. Hence, the present solitary method can be used for systematic analysis of biological samples.