| In this study, a new microextraction method, termed glass-filter-based dispersive liquid-phase
microextraction using a lighter-than-water deep eutectic solvent, was developed for the extraction and
preconcentration of different classes of pesticides, including dichlorvos, diazinon, simazine, prometryn,
terbutryn, bifenthrin, fenpropathrin, bromopropylate, phosalone, and deltamethrin, from fruit juice and
vegetable samples. In this method, a U-shaped homemade device with different diameters containing
filter glass tubes was used as an extraction device. An aqueous sample solution containing the analytes
was transferred into the device on top of the glass filter, and a lighter-than-water extraction solvent
(ChCl:pivalic acid) was placed under the glass filter. The extraction solvent was passed through the glass
filter with the aid of an air flow and interred into the aqueous solution. By this action, the extraction
solvent was dispersed in the aqueous solution, and 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 were obtained without centrifugation. The enriched analytes were determined by gas
chromatography-mass spectrometry. Under the optimum extraction conditions, the method showed
low limits of detection and quantification in the ranges of 3–26 and 10–92 ng L1 in fruit juices and
10.0–16.9 and 35.0–59.8 ng kg1 in vegetable samples, respectively. Extraction recoveries and enrichment
factors ranged from 79–96% and 263–319, respectively. Relative standard deviations of r8% for
the extraction of 150 ng L1 of each pesticide were obtained for the intra- (n = 6) and inter-day (n = 5)
precisions. Finally, different fruit juices and vegetable samples were successfully analyzed using the
proposed method, and diazinon and bromopropylate were determined in some samples. |