Dispersive liquid phase microextraction method performed in a home–made device using menthol based lighter than water deep eutectic solvent in extraction of some pesticides in farmer urine and plasma samples followed by gas chromatography–mass spectrometry

Pesticides are chemical compounds that are intended to control weeds, insects, herbs and pests [1]. These compounds are used on large scale in agricultural activities. The pollution of environmental compartments involves a serious risk to the environment and to human health as well, due to either direct exposure or residues in food and drinking water [2]. The pesticides risks to human health have been widely evaluated, but their risks to farmer health are one subject that has so far received little attention. This is true in developing countries the major pesticide users are farmers [3]. In this work, a new disperser–less and centrifuge–less dispersive liquid phase microextraction performed in a home–made extraction device has been developed for the extraction and preconcentration of some pesticides in plasma and urine samples followed by gas chromatography–mass spectrometry. For this purpose, a U–shaped glass device with a glass filter was designed and a new deep eutectic solvent lighter than water was used as an extraction solvent. The extraction solvent was forced to pass through the glass filter under air stream and it was dispersed as tiny droplets in whole parts of the aqueous solution placed on the filter. By this action the analytes were extracted into the fine droplets of the extraction solvent. The produced droplets of the extraction solvent went up through the solution and collected on the aqueous phase without centrifugation. Under the optimum extraction conditions, the method showed low limits of detection in the ranges of 2–17 and 4–36 ng L−1 in urine and plasma, respectively. Extraction recoveries were in the range of 79–97%. Enrichment factors were obtained from 379 to 485 in urine and 158–194 in plasma. Finally, plasma and urine samples of farmers were successfully analyzed using the proposed method.