Copolymerized Natural Deep Eutectic Solvent Encapsulated in Calcium Alginate Beads: Application as a Green Sorbent for Analysis of Multiclass Pesticides in Nonalcoholic Malt Beverages by GC-MS/ SIM

A novel sorbent material consisting of a copoly-meric deep eutectic solvent (DES) gel doped in calcium alginate (CA) hydrogel beads was synthesized and used in a green micro -solid phase extraction of 24 pesticides in 8 nonalcoholic malt beverages. The analyses were performed by gas chromatography- mass spectrometry/selective-ion monitoring. The DES was prepared by combining thymol (Thy, thyme oil) and methacrylic acid (MAA, can be obtained from Roman chamomile oil) in a 1:1 molar ratio via the heating-stirring method. Then, it was copolymerized using ammonium persulfate as a polymerization initiator and ethylene glycol dimethacrylate (EGDMA) as a crosslinking monomer through thermally induced free-radical reaction and finally was encapsulated in CA beads. The DES was characterized by Fourier transform infrared, Fourier transform nuclear magnetic resonance, and scanning electron microscopy techniques. A comparison study indicated that t extractionhe efficiency of the modified CA with polymeric DES (CA/[poly(MAA-co-EGDMA)]:[Thy]) was 1.5-3.4-fold higher than unmodified CA hydrogel beads. The influence of significant parameters affecting extraction efficiency was optimized. The method was validated by the matrix effect, specificity, precision, limits of quantifications (0.010-0.230 mu g L-1), matrix-matched calibration linearity (0.010-300 mu g L-1), and determination coefficients (r2 = 0.990-0.998). The method was successfully utilized for the detection of pesticide residues in nonalcoholic malt beverage samples, and the obtained relative recoveries were 68.2-115.6% (relative standard deviation < 10.2%). The procedure's greenness was evaluated by the Complex Green Analytical Procedure Index and the Analytical Eco-Scale protocols. This paper is the first report on the preparation and utilization of this novel sorbent for the analysis of pesticides in nonalcoholic malt drinks.