Covalent organic frameworks hybridized polymeric high internal phase emulsions with amphiphilicity for extraction of trace bisamide insecticides in food samples.

Polymeric high internal phase emulsions decorated with covalent organic frameworks (polyHIPEs-COFs) were synthesized and used as the sorbent for cyantraniliprole and chlorantraniliprole. Pickering high internal phase emulsions stabilized by covalent organic frameworks solid particles and liquid surfactants (Span80 and polyvinylpyrrolidone) endow the composites with open-cell structures and superwettability. The amphiphilicity and open-cell structures enable rapid adsorption and desorption for cyantraniliprole and chlorantraniliprole, and the solid-phase extraction process can be completed in 5 min. The adsorption efficiencies of polyHIPEs-COFs for cyantraniliprole and chlorantraniliprole are above 85.19%, but lower than 10% for fenvalerate, anti-aphid, and chlorpyrifos, demonstrating the good adsorption selectivity for cyantraniliprole and chlorantraniliprole. The adsorption efficiencies of cyantraniliprole and chlorantraniliprole using a same polyHIPEs-COFs and five different batches of polyHIPEs-COFs range from 94.25 to 100.00%, revealing the good reproducibility of the sorbent. In addition, the polyHIPEs-COF-based solid-phase extraction combined with high-performance liquid chromatography-ultraviolet detector (HPLC-UV) was developed for determination of bisamide insecticides in vegetable (eggplants, tomatoes, and peppers) samples. Results showed that the method was feasible to determine the cyantraniliprole and chlorantraniliprole in real vegetable samples with a linear range of 0.012-1.2 μg/kg and limits of detection of 0.0075-0.0090 μg/kg. The recoveries of cyantraniliprole and chlorantraniliprole spiked in vegetable samples ranged from 85.00 to 100.00% with relative standard deviations less than 3.52%. The study indicates the feasibility of amphiphilic polyHIPEs-COFs in extraction and enrichment of bisamide insecticides from vegetable samples for HPLC-UV analysis.