Development and Validation of a Simple and Rapid HPLC Method for the Evaluation of Pesticide Residues in Plasma Samples of Farmers; Application in Toxicological and Risk Assessment Studies

Background: In the present work, an analytical method based on high performance liquid chromatography-diode array detection has been reported to evaluate the presence of some widely used pesticides in plasma samples of the farmers exposed to the pesticides in farm lands and rural zones. Prior to instrumental analysis, the analytes are extracted using a two-step extraction procedure based on a combination of cold-induced homogenous liquid-liquid extraction and dispersive liquid-liquid microextraction. Methods: In this method, initially acetonitrile is added to a tube containing the plasma sample and the mixture is vortexed. By this action, the proteins of plasma are precipitated at the bottom of the tube after centrifugation and a homogenous solution is collected on them. Subsequently, the mixture is placed in liquid nitrogen for a few seconds to freeze the aqueous phase. As a result, the homogenous state is broken and the analytes are extracted into the supernatant organic phase (acetonitrile), which is subsequently removed and used in the following microextraction method. Results: Under the optimum extraction conditions, the proposed method indicated good extraction recoveries (59-80%), satisfactory repeatability (relative standard deviation <= 6% for intra- and inter-day precisions), and low limits of detection (1.4-2.3 mu g L-1). Conclusion: Finally, various plasma samples of the farmers were analyzed by the introduced method. Ease of operation, being environmentally friendly, rapidity, and low cost can be the main advantages of the introduced approach.