A rapid, environmentally friendly, and reliable method for pesticide analysis in high-fat samples

Abstract

This report describes the development and validation of a simple, rapid, and efficient method in which solid-phase extraction followed by analysis in a gas chromatograph equipped with an electron capture detector (SPE-GC-ECD) is used for the simultaneous determination of dicofol, dieldrin, endosulfan, and permethrin in rat adipose tissue. This study targeted pesticides for which controversies exist regarding the harm that they may cause to humans, such as endocrine disruption or cancer, and that have also been found in recent years in vegetables consumed by the Brazilian population. The analytical procedure was optimised for SPE extraction and for GC-ECD conditions. The optimised method includes the extraction of the samples with n-hexane followed by an SPE procedure in which deactivated neutral alumina cartridges are used as the sorbent and a mixture of n-hexane:dichloromethane is used for elution. Recovery studies with spiked samples were used to evaluate the method's efficiency. Mean recoveries ranged from 75% to 119% with relative standard deviations (RSD) < 19%. Quantification limits (LOQs) were 0.05 mg kg(-1) for dieldrin and endosulfan and 0.5 mg kg(-1) for dicofol and permethrin. The matrix effect was pronounced for all of the pesticides studied and ranged from 26% to 49%. In comparison to other related methods, this method requires less time and solvent and allows for rapid isolation of the target analytes with high selectivity. This method therefore allows for the screening of numerous samples and can also be used for routine analyses. (C) 2012 Elsevier B.V. All rights reserved.