Development of a Multi Residue Method for the Quantification of 45 Pesticides Using Gc-Ms/Ms and Study of Peeling Effect on Pesticide Residues in Citrus Fruits

An analytical method was developed and validated for the determination of 45 multi-class pesticide residues in citrus fruit samples collected from and around Pulivendula, India, using GC-MS/MS (Gas chromatography with tandem mass spectrometry) followed by the QuEChERS extraction method . The linear regression coefficients (R-square) of the methods range from 0.998 to 0.999, and the Limit of Detection (LOD) and Limit of Quantification (LOQ) are 1.56 to 25.23 ng/mL and 4.72 to 76.47 ng/mL, respectively. Recoveries of all spiked pesticides range from 82.6 to 117.6%, with a RSD (Relative Standard Deviation) less than 11.2%. The results show that 42 out of 45 pesticides were detected in whole citrus fruit pulp (with peel) samples. Fenthion, bifenthrin, and fenvalerate were not detected. In the collected citrus samples, phorate (21.71 µg/kg), and ethion (51.47 µg/kg) insecticides are present above the Maximum Residue Level (MRL), but cypermethrin (25.89 µg/kg) was detected below the MRL. 13 out of 45 pesticides were detected in edible parts of citrus fruit (without peel) samples, with ethion having the highest residue. All pesticides were within the MRL limits prescribed by the European Union (EU) and Codex regulations for MRL in citrus fruits, and peeling was found to be one of the best ways to get rid of pesticide residues.