Method Development and validation in GC-MS/MS for analysis of pesticide residue in millet grains

Pesticide residues, particularly organophosphates, have emerged as a grave and pervasive concern in food products, posing threats to environmental integrity and human health. In an era when ensuring food safety is paramount, the need for reliable analytical methods cannot be overstated. To address this pressing issue, we have developed a robust analytical method employing GC-MS/MS. This method, augmented with slight modifications in sample preparation using the QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) technique, was meticulously validated to ensure its accuracy and dependability. In this study, we focused on organophosphate pesticides, including chlorpyrifos, dimethoate, and profenofos, known for their extreme toxicity and frequent association with acute poisonings. The millet varieties chosen for this investigation were Kodo millet, little millet, and Barnyard millet that are considered as dietary staples in many regions. The method's efficiency and precision were evident, and all three pesticides exhibited strong linearity, with correlation coefficients (r²) exceeding 0.99. The limit of detection (LOD) and limit of quantification (LOQ) were found to be impressively low at 0.005 mg kg⁻¹ and 0.015 mg kg⁻¹, respectively. Subsequently, the validated method was applied to millet samples, including Barnyard millet, Kodo millet, and little millet.