Preparation of nicotine surface molecularly imprinted polymers for selective solid-phase extraction of nicotine from zero-level refill liquids of electronic cigarettes

Abstract

A new method of molecularly imprinted polymer solid-phase extraction (MISPE) coupled with gas chromatography-mass spectrometry was developed for the determination of nicotine in the zero-level refill liquids of electronic cigarettes. The surface molecularly imprinted polymers (SMIP) were synthesized on the surface of vinyl-SiO₂ nanospheres using nicotine as a template, methacrylic acid as a functional monomer, and ethylene glycol dimethacrylate as a cross-linker in toluene solution. The prepared SMIPs showed high adsorption capacity (247.0 μmol g⁻¹), excellent imprinting factor (4.40), and high selectivity toward nicotine with selectivity coefficients higher than 2.9. Finally, the SMIPs were successfully utilized as solid-phase extraction (SPE) sorbents for the extraction of nicotine in the zero-level refill liquids of electronic cigarettes (ECs). The newly established method showed good linearity in the range of 2.00–40.00 μg mL⁻¹. The limit of detection (LOD, S/N = 3) was 0.50 μg mL⁻¹, the limit of quantification (LOQ, S/N = 10) was 1.66 μg mL⁻¹, and the average recoveries range from 76.2% to 83.9% with relative standard deviations lower than 6.4% (n = 6). These results indicated that a feasible and reliable method was developed for the determination of nicotine in zero-level refill liquids of electronic cigarettes, which could provide an alternative solution for the quality control of electronic cigarette products.