Evaluation as time-dependent of pesticides applied in pre-harvest period of grown vegetables: removal of pesticide residues in the vegetables

Pesticide use has benefits such as increasing the quality and amount of food required to sustain the human population. However, its harmful effects on the environment and human health are of great concern. The aim of this study was to evaluate concentrations as timedependent of the pesticide and the removal of pesticide residues in vegetable samples with the aid of the QuEChERS 2007.01 procedure. The analytical method has been validated according to SANTE/12682/2019. Good linearity (2.5–100 ng/mL, R2 > 0.99) was observed, and the recovery yields ranged from 94.76% to 104.03%, repeatability (RSDr) ranged from 2.33% to 4.59% and reproducibility (RSDwR) ranged from 4.06% to 8.40%. LOD and LOQ values were determined to be 3.00 ng/g and 10.00 ng/g, respectively. The grown tomato, eggplant and cucumber samples were sprayed with drugs against pests and diseases. Imidacloprid in the grown tomato, cucumber and eggplant samples was determined to be 0.026, 0.186 and 0.096 mg/kg, respectively. Trifloxystrobin was determined to be 0.102, 0.129 and 0.063 mg/kg, respectively. It was determined that pesticide residue in vegetable samples decreases by washing and peeling but does not disappear completely. The peeling process was determined to be more effective than washing. The concentration of pesticide residues in the shell part was found to be hight than in the whole product. Thus, it is important to consume vegetables with their skin peeled and to consume the unpeeled ones by washing them with water at least.