Biopolymers based-dispersive solid phase extraction combined with deep eutectic solvent-based dispersive liquid-liquid microextraction for the extraction of several pesticides from fruit juices prior to GC-FID analysis

A new analytical method based on a combination of dispersive solid phase extraction with dispersive liquid-liquid microextraction was developed for the extraction of several pesticides (diazinon, prometryn, haloxyfop methyl, hexaconazole, and fenpropathrin) in fruit juice samples. For this purpose, firstly, the pesticides were extracted by a mixture of bio-sorbents (chitosan: agarose: cellulose with a weight ratio of 4:1:1) from fruit juices and in the following they were more concentrated by a deep eutectic solvent-based dispersive liquid-liquid microextraction procedure. The effective parameters influencing both steps were investigated and optimized through a "one-factor-at-a-time" approach. Based on the figures of merit evaluated for the developed method, calibration curves were linear in the range of 0.70-4000 ng mL-1. Limits of detection and quantification were in the ranges of 0.09-0.21 and 0.30-0.70 ng mL-1, respectively. The precision of the developed method was evaluated by performing the method on six aqueous standard solutions (10 ng mL-1 of each pesticide) in a same day and various days. The obtained relative standard deviations for intra- and inter-day precisions were in the ranges of 2.9-5.9% and 5.2-6.3%, respectively. The developed method was successfully employed for multi-residue determination of pesticides in some fruit samples. The relative recoveries were from 88 to 101%.