Green supramolecular solvent-based microextraction approach using naturally-occurring components for chromatographic...

In this study, a green supramolecular solvent-based microextraction approach using naturally-occurring components (decyl glucoside and linalool) for preconcentration of agricultural benzimidazole fungicides (thiabendazole and carbendazim) from vegetables was developed. Supramolecular solvent formation in aqueous solution of decyl glucoside in the presence of linalool was demonstrated for the first time. The developed microextraction technique assumed mass-transfer of the analytes from sample matrix to micellar solution of decyl glucoside followed by injection of liquid linalool into the obtained supernatant for coacervation and enrichment of the target analytes. Different terpenes and terpenoids were evaluated for coacervation and supramolecular solvent formation. Linalool ensured high extraction recoveries (>98 %) and maximum enrichment factors for thiabendazole and carbendazim. The technique was successfully used for the determination of the fungicides in real vegetables (potato, beetroot and ginger samples) by high-performance liquid chromatography with fluorescence detection. At optimal conditions providing the highest analytical signals (3 g of vegetable sample, extraction into 4.5 % solution of decyl glucoside, microextraction with 40 μL of linalool): for thiabendazole, limit of detection was 0.5 μg kg^-1, and linear range was found to be 1.5-1000 μg kg^-1; for carbendazim, these parameters were 4 and 12-10000 μg kg^-1. The relative standard deviation for intra- and inter-day precision did not exceed 6 %. This research proves that supramolecular solvent can be obtained from naturally-occurring and available components such as alkyl polyglucosides and terpenoids.