SiO2/polyvinylimidazole hybrid polymer as a sorbent for extraction by matrix solid-phase dispersion (MSPD): synthesis, characterization, and evaluation

Abstract

A novel hybrid polymer was developed and evaluated as a sorbent for the matrix solid-phase dispersion (MSPD) extraction of pesticides. The hybrid polymer was synthesized by the sol–gel method and by free radical polymerization. The chemical structure of the resulting hybrid polymer (SiO2–PVI) was confirmed by Fourier transform infrared spectroscopy (FTIR). Thermal analyses suggest that the polymer consists of an organic/inorganic ratio of 28:72 wt/wt%. Scanning electron microscopy (SEM) and elemental analysis (EDS) revealed particle aggregates and a rough surface and suggested that the polymer is primarily composed of SiO2. The obtained pore size was appropriate for use in a solid-phase extraction support. X-ray photoelectron spectroscopy (XPS) was used to assess the surface composition of the hybrid polymer and indicated the presence of C, N, O, and Si. The material was tested for extraction of five selected organophosphorus pesticides (OPPs) in propolis using gas chromatography–mass spectrometry (GC/MS). In experiments performed in triplicate at 1.0 μg mL−1, pesticide recovery was in the range of 81–122%. In addition, the sorbent hybrid polymer (SiO2–PVI) demonstrated good repeatability (RSD≤11 %), on the same order as C18 (commercial sorbent) when tested under the same conditions. These results suggest that SiO2–PVI hybrid polymer is a good sorptive material that is comparable to the commercially utilized C18 and can be used in MSPD for the extraction of organophosphorus pesticides