Dispersive liquid-liquid microextraction based on solidification of deep eutectic solvent droplets for analysis of pesticides in farmer urine and plasma by gas chromatography-mass spectrometry

A new disperser-less, centrifuge-less, ice-bath less and deep eutectic solvent-based solidification of organic droplets dispersive liquid-liquid microextraction performed in a laboratory-made extraction apparatus coupled with gas chromatography-mass spectrometry has been developed for the analysis of ten pesticides in plasma and urine samples. For this purpose, a glass tube containing a glass membrane filter was fabricated and a new synthesized deep eutectic solvent with density lighter than water was used as an extractant. The extraction solvent was forced to pass through the glass filter under N-2 stream and it was dispersed as the fine droplets in the sample solution. In this step, the analytes were transferred into the droplets. Due to low density of the extractant, it was collected on top of the sample solution without centrifugation. After performing the validation of the method, low limits of detection in the ranges of 2-17 and 4-36 ng L-1 in urine and plasma were obtained, 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 effectively analyzed using the method.