Development of an advanced analytical technique for detecting multiple pesticide residues in vegetables through liquid chromatography tandem mass spectroscopy (LC-MS/MS)

A comprehensive LC-MS/MS method, which employs Positive Electrospray Ionization (PEI) and Multiple Reaction Monitoring (MRM) was developed for the simultaneous determination of 35 pesticides belonging to various chemical classes in tomato, brinjal, chili, and okra samples. Extraction was facilitated using a modified QuEChERS method, which allows efficient sample analysis in a single run. Calibration curves for each pesticide exhibited linearity within the concentration range of 0.0025 to 0.1 µg mL^-1, with correlation coefficients ranging from 0.993 to 0.999. Mean recoveries at five fortification levels (0.01 to 0.5 µg kg^-1) ranged from 80 to 90%, demonstrating satisfactory precision (RSD < 20%). The matrix effects, mitigated through an optimized cleanup process, were observed within the range of 6.42% to 19.52%. The developed method having the limit of quantification of 0.01 mg kg^-1 for all 35 pesticides, proved to be highly sensitive and rapid for multi-residue estimation in diverse vegetable samples. Subsequently, the method was used to analyze the market samples from Varanasi, India, which revealed the presence of pesticides like Chlorpyrifos, Chlorantraniliproleand Indoxacarb in tomato, brinjal, chili and okra. Therefore, the method could be considered as a robust tool for monitoring pesticide residues in vegetables, aiding in quality assessment and regulatory compliance in the agriculture sector.