Preparation and application of an imidazolium-based poly (ionic liquid) functionalized silica sorbent for solid-phase extraction of parabens from food samples

In this work, an imidazolium-based poly (ionic liquid) (poly(1-octyl-3-vinyl- imidazolium naphthalene sulfo-nate)) functionalized silica (poly(C(8)VIm(+)NapSO(3)(-)) @SiO2) was successfully prepared for the determination of parabens in food samples. The prepared poly(C(8)VIm(+)NapSO(3)(-))@SiO2 was characterized by Fourier transform infrared spectrometry (FT-IR), X-ray photoelectron spectrogram (XPS) and Scanning electron microscopy (SEM). The simulation calculation results indicated that the suitable binding energies were between the polymeric ionic liquids and parabens, and the main interactions for extraction were hydrogen bonding, electrostatic and pi-pi stacking interactions. In addition, compared with commercial extraction materials, the prepared poly (C(8)VIm(+)NapSO(3)(-))@SiO2 sorbent showed comparable or even better extraction performance towards parabens. The effective parameters were optimized by a combination of the univariate method and Box-Behnken design (BBD). Under the optimum conditions, coupled with high performance liquid chromatography (HPLC), wide linear ranges (1.0-800 mu g L-1), good linearity (R-2 >= 0.9997) and low limits of detection (0.1 mu g L-1) were ob-tained. In addition, the intra-day and inter-day relative standard deviations (RSDs) were all lower than 6.3%. Moreover, the proposed method was successfully used for the determination of parabens in food samples and satisfactory recoveries in the range of 76.9-97.4% were obtained. The results indicated that the proposed method had good sensitivity, accuracy and precision for the detection of parabens in food samples.