Uso das técnicas QuEChERS e CG-EM na gestão ambiental para monitoramento de resíduos de agrotóxicos organofosforados em pimentão

Abstract

The development of analytical methods is crucial for the monitoring of pesticide residues in food, as it ensures that the concentrations of these compounds are within the limits considered safe for health, as well as promotes Good Agricultural Practices (GAP), contributing both to society and the environment. This work describes the validation of an analytical methodology based on the QuEChERS-citrate method (Quick, Easy, Cheap, Effective, Rugged, and Safe) and gas chromatography coupled to mass spectrometry (GC-MS) for the simultaneous analysis of six agrochemicals organophosphates (chlorpyrifos dichlorvos, disulfotom, etoprophos, fenchlorphos and prothiofos) in organic and non-organic peppers. Chili has been chosen because it is a very consumed product in Brazil and in the world, and mainly because in the last years the Para (Food Waste Analysis Program) has identified several samples of peppers outside the conformity standards, being between 2010 and 2012 the first on the list of foods most contaminated by organophosphorus pesticides. The QuEChERS-citrate method generated a cleaner extract, helping to maintain a longer life for both liner and column. The statistical tests t-test and F-test were applied to verify the significance of the parameters and regression of the analytical curves obtained in the matrix. The study of the matrix effect (MS) was performed due to the complexity of the sample, in which all the compounds evaluated had a negative effect. The pesticides studied showed good linearity with coefficients of correlation higher than 0.99. The limits of detection (LOD) ranged from 0.002 mg.kg-1 to 0.039 mg.kg-1 and the limits of quantification (LOQ) ranged from 0.006 mg.kg-1 to 0.130 mg.kg-1. Only one of the samples in the local market (Fortaleza-CE) presented contamination by the chlorpyrifos pesticide, which is not allowed by ANVISA in this type of crop.