A polydimethylsiloxane/deep eutectic solvent sol-gel thin film sorbent and its application to solid-phase microextraction of parabens

Abstract

A novel, efficient and reproducible thin-film solid-phase microextraction method using the polydimethylsiloxane/deep eutectic solvent sol-gel as coating material was developed for preconcentration of parabens from environmental samples.New sorbent materials consisting of polydimethylsiloxane with nine new synthesized deep eutectic solvents were prepared by the sol-gel method, and these materials were used to prepare thin film coatings on a mesh support. Among obtained compounds, the highest efficiency in the extraction of parabens was demonstrated by a sorbent consisting of trihexyltetradecylphosphonium chloride and n-docosanol in a molar ratio 1:2 mixed with polydimethylsiloxane.For the proposed method, the parameters affecting the extraction efficiency of parabens were optimized, including the coating material type based on polydimethylsiloxane/deep eutectic solvent, the sample volume, the salting-out effect, the pH of the sample, the extraction time, the desorption solvent and time. The limits of detection and quantitation were from 0.023 to 0.062 ng mL−1 and 0.076–0.201 ng mL−1, respectively, and the enrichment factors ranged from 174 to 186. Under optimal conditions, the proposed method based on measurements for river and lake water achieved good precision between 2.7 and 5.9% and recovery ranging from 79.1 to 88.1%. The developed method was successfully applied to determine trace levels of parabens in the samples of surface waters collected from rivers and lakes.