Estudo da remoção de resíduos de agrotóxicos em alface

Abstract

The consumption of in natura food has increased due to changes in habits for a healthier diet. However, a concern has arisen related to the presence of pesticides residues in food, which has raised questions about food safety. With the purpose of promoting the removal of pesticide residues in hydroponic lettuce, were evaluated the effects of washing with water and cleaning solutions containing NaClO (2.6%), iodine tinture (2%), NaHCO3 (5%), H2O2 (6%), all at room temperature, but with exposure times ranging from 20 to 60 min. In the removal study the lettuces were cultivated in hydroponics and contaminated by spraying, with the pesticides carbendazim and deltamethrin. For the determination of residues of the pesticides in study, an analytical methodology was validated, adapted. The extraction method used was the original QuEChERS method, with the use of Grafitized Carbon Black - (GCB) and for HPLC-DAD analysis. The values established for the limit of detection (LOD) were 0.021e 0.050 mg kg-1, and, for the limit of quantification (LOQ) 0.069 and 0.165 mg kg-1for carbendazim and deltamethrin, respectively. The removals provided by the NaHCO3 solution (5%) ranged between 67.15% - 98.59%, but caused changes in vegetable texture. As a result, the use of H2O2 (6%) was more efficient, with removal percentages between 25.23% and 96.91%, of the residues on the surface of the lettuce and without alteration in the leaf of this vegetable. The most favorable time for removal was 40 min.