Desenvolvimento e validação de metodologia para determinação de resíduos de pesticidas no estipe de coqueiro (Cocos nucifera L.), utilizando as técnicas de MSPD e HPLC-DAD

Abstract

The coconut is subject to attack by pests and diseases causing losses to producers. As a result, the application of pesticides is still one of the most commonly used practices to control these pests. However, there are studies that demonstrate the efficacy of this type of control. Therefore, this paper proposes the development of methodology using the dispersion technique of matrix solid phase (MSPD) and high performance liquid chromatography with diode array detector (HPLC-DAD) for the study of pesticides (carbofuran, β- cyfluthrin, difenoconazole, spirodiclofen and thiophanate methyl) applied in the stem that can contaminate the fruit, the principal product of coconuts consumed. The methodology developed by the stem MSPD used as Florisil® adsorbent and 40 mL of cyclohexane: acetone in a proportion (80:20, v/v) as eluting solvent. For concentrations of 0.05, 0.5, 1.0 and 2.0 μg g-1, the mean recovery in a range from 57.5 to 114.3% and the coefficient of variation of a 2 to 19.2%. Linearity ranged from 0.9974 to 0.9996 considering the range 0.04 to 20 μg mL-1. And the threshold values for detection and quantification ranged from 0.02 to 0.5 μg g-1. Thus, the method is efficient for the study of pesticide applied to the stem.