Graphene oxide-ionic liquid used as solid-phase microextraction coating for polyphenolic compounds’ extraction and determination with gc-ms after on-fiber derivatization in wine

Abstract

We describe the use of a home-made fiber coated by graphene oxide modified by an ionic liquid having methylimidazolium cation with an amino-functional group for the extraction of polyphenolic compounds (P.C.s). We then performed the determination by gas chromatography coupled with mass spectrometry after on-fiber derivatization. The authors optimized the main parameters influencing the extraction and derivatization processes. The on-fiber derivatization was employed within 15 min at 60ºC using 20 µL of trimethylsilyl reagents. Under the optimized conditions, the calibration curves for 12 P.C.s were linear from 0.1 to 1000 µg/L, and the detection limits were between 0.02 and 0.1 µg/L. We determined the single fiber repeatability obtained for all calibration points and the fiber to fiber reproducibility for 100 µg/L to be < 14.82% and < 5.87%, respectively. The extraction efficacy of the home-made fiber due to high intermolecular and electrostatic attractions was much better than the commercial fibers. We successfully applied the method to the analysis of P.C.s in wine samples with the recoveries from 72.8 to 99.9%.