Modified QuEChERS Combination with Magnetic Solid-Phase Extraction for the Determination of 16 Preservatives by Gas Chromatography-Mass Spectrometry

In this paper, based on the mechanism of the quick, easy, cheap, effective, rugged and safe (QuEChERS) method, a novel graphene grafted silica-coated Fe3O4 (Fe3O4@SiO2@G) was synthesized and applied as the efficient magnetic solid-phase extraction (MSPE) adsorbent for rapid cleanup of vegetable samples prior to analyzing 16 preservative residues by gas chromatography-mass spectrometry (GC-MS). The method, which took advantages of the novel nanoparticle adsorbent and an external magnetic field separation targets from samples, not only could avoid the time consuming of the traditional solid-phase extraction, but also could be developed for simultaneous determination of 16 preservative residues in vegetables. Various experimental parameters that could affect the extraction efficiencies have been investigated. Under the optimum conditions, 16 preservatives showed good linearity over the range of 0.02-2.00 mg/L and correlation coefficients (R (2)) of 0.9946-0.9998. The limits of detections (LODs) were in the range of 0.21-11.50 mu g/kg. The recoveries of 16 preservatives ranged from 78.3 to 116.7 %, and the relative standard deviations (RSDs) ranged from 1.4 to 11.9 %.