Residual Determination of Multiple Pesticides in Vegetable Samples by LC-MS/MS Coupled with Modified QuEChERS-dSPE Ionic Liquid-Based DLLME Method

Abstract

As a matter of fact, the Dietary Guidelines of the United States of America recommended the consumption of more fruits and vegetables to support the healthy condition of the body. Unfortunately, these food materials are being accumulated with pesticidal residues due to the continuous miss-management and excessive application of the chemicals during pre and post-agricultural practices, which compels multiple analysis of pesticidal residues to know their concentration levels for the betterment of food security and safety. For that matter, multi-residues of Thiamethoxam, Propamocarb, Carbaryl, Metalaxyl, Baycarb, Thiobencarb, Diazinon, and Dursban pesticides were determined in the samples of lettuce, garlic, ginger, and bell-pepper using modified QuEChERS-dSPE Ionic Liquid-based dispersive liquid-liquid microextraction (DLLME) method coupled with LC-MS/MS instrument and validated (European Union Guideline). Resultantly, the accuracy (87-127%) and precision (0–22%) were mostly within the acceptable range for the former (70-120%) and latter (≤20%). Meanwhile, the limit of detections (0.01-0.28 µg/kg) and limit of quantitations (0.03-0.93 µg/kg) were satisfactory. The concentration range (5–400 µg/kg) of calibration curves for the evaluated linearity were linear with coefficient of regressions greater than 0.99. The matrix effects for all the analyzed samples were very weak and less effective (≤ -86%). The range (1–25%) for the estimated measurement uncertainties were certifiable and acceptable (≤ 50%). Therefore, the sample preparation method prove effective as validated and useful for the multiple determination of pesticides residues in the analyzed vegetable samples, which are presumably safe for consumption against health issues.