Pesticide Determination in Fresh Coconut Water (Cocos nucifera Linn.) by GC-MS Using Microwave-Assisted Liquid-Liquid Extraction

Fresh coconut (Cocos nucifera) water, a popular beverage in tropical countries, is often exposed to pesticide contamination due to agricultural practices. Thus, this work proposed the simultaneous determination of 36 pesticides in fresh coconut water samples using liquid-liquid extraction, drying assisted by a household microwave oven, and gas chromatography-mass spectrometry (GC-MS) analysis. Limits of detection varied from 5.4 (disulfoton) to 9.6 ng L^-1 (parathion-methyl). Nine pesticide residues were detected (dimethoate, γ-HCH, β-HCH, 4,4’-dichlorodiphenyldichloroethylene, endosulfan II, 4,4’-dichlorodiphenyldichloroethane, 4,4’-dichlorodiphenyltrichloroethane, endrin ketone, and methoxychlor) with concentrations from < limit of quantification to 5,768.34 ± 1.64 ng L^-1. Dimethoate was quantified in all samples, indicating its recent use. The proposed methodology offers several advantages, including the use of small sample volumes and solvent extraction, which eliminates the need for costly cartridges and reduces waste production. Additionally, the obtained results can be valuable for regulatory agencies, aiding in the mitigation of environmental damage and the protection of human health.

Keywords:
liquid-liquid extraction; microwave oven; contamination; beverage; dimethoate