Ionic liquid-mediated molecularly imprinted solid-phase extraction coupled with gas chromatography-electron capture detector for rapid screening of dicofol in vegetables

•A simple and rapid IL-MIPs-SPE-GC method for determination of dicofol from vegetables.•MIPs prepared by ionic liquid as auxiliary solvent and α-chloro-DDT as dummy template show high affinity to dicofol.•Rapid screening of dicofol from vegetables and the interferences from sample matrix were eliminated.•Extraction efficiency was markedly increased with reduced equilibrium time.•This method improved the selectivity and eliminated the effect of template leakage on quantitative analysis.

New ionic liquid-mediated molecularly imprinted polymers (IL-MIPs) were prepared by precipitation polymerization using 1-butyl-3-methylimidazolium hexafluorophosphate (BMIM+PF6−) as the auxiliary solvent, α-chloro-DDT as the dummy template, and they were successfully applied as the sorbents of solid-phase extraction (SPE) for rapid screening of dicofol from cabbage, tomato, and carrot samples. The IL-MIPs were characterized by FTIR, FE-SEM, static adsorption and chromatographic evaluation, and the results revealed that the IL-MIPs had higher adsorption capacity and selectivity to dicofol in aqueous solution than that of ionic liquid-mediated non-imprinted polymers (IL-NIPs) and non-imprinted polymers (NIPs). Under the optimized conditions, the IL-MIPs-SPE-GC method offered good linearity (0.4–40.0 ng g−1, r2 = 0.9995) and the average recoveries of dicofol at three spiked levels were in a range of 84.6–104.1% (n = 3) with RSD ≤ 7.6%. The proposed method obviously improved the selectivity and purification effect, and eliminated the effect of template leakage on dicofol quantitative analysis.