Mir Ali Farajzadeh
1,2* 
, Ali Mohebbi
1, Mohammad Reza Afshar Mogaddam
3,41 Department of Analytical Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz, Iran.
2 Engineering Faculty, Near East University, 99138 Nicosia, North Cyprus, Mersin 10, Turkey.
3 Food and Drug Safety Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.
4 Pharmaceutical Analysis Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.
Abstract
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 μg 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.