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.