Comparative Study of QuEChERS Methods for Monitoring Pesticides in Milk using GC-MS/MS

The presence of pesticides in milk is a serious concern at the global level, which can threaten human health. Detection of pesticides in milk is a challenge due to their small concentration and large amounts of other interfering substances that can be co-extracted along with the pesticides. In this study, we have compared two variants (original and acetate) of quick, cheap, effective and safe (QuEChERS) method to evaluate the efficiency and suitability of these methods for the extraction of organochlorine and organophosphorous residues from milk using GC-MS/MS. The acetate method was found to be more efficient in terms of recovery of all the studied pesticides, except monocrotophos. It resulted in good linearity (R² > 0.9928% in matrix and >0.9940% in solvent), recovery (71.69%–99.38%) over the range 10–250 ng/ml and precision of RSD% < 20%. This method can be easily applied for the extraction of pesticide residues in milk and its products, and further quantification using GC-MS/MS in the dairy sector.