Solvent-Free Synthesis of Phenolic Hydroxyl Enriched Ordered Mesoporous Polymer as an Efficient Solid-Phase Microextraction Coating for the Determination of Trace Phenols in Food Samples

Abstract

The determination of trace phenols in food samples is of great significance, but it is still very challenging due to the low concentration and complex matrix. A robust method was developed to determine trace phenols in food sample by combining headspace-solid phase microextraction (HS-SPME) with gas chromatography-mass spectrometry (GC-MS). The hydroxylated ordered mesoporous polymer (OMP-OH) synthesized by solvent-free strategy possessed ordered mesoporous structure and high specific surface area and was used as SPME fiber coating. Factors affecting the extraction efficiency were optimized, including extraction time, extraction temperature, pH value, salt effect, and desorption conditions. Under the optimal conditions, OMP-OH coating exhibited a high capability for the enrichment of phenols, which was 2~8 times that of commercial SPME coating. Moreover, the coating can be reused for more than 150 times without a significant change in performance. Linear ranges of this method were 0.5~10000 ng L−1, of which 5~10000 ng L−1 for 2-nitrophenol and 1~10000 ng L−1 for 2, 4-dichlorophenol. The limits of detection (LODs) for phenols in tomato and grape are 0.19~2.13 ng L−1 and 0.21~2.41 ng L−1, respectively. High enrichment factors (439~1851), good precision (RSD< 8.87%), and superior reproducibility (RSD< 10.0%) were obtained. Ultimately, the established method was successfully applied to quantify the phenols in real food samples, i.e., tomato and grape. The results demonstrated that the established method was very promising for the determination of trace phenols in food samples with complex matrix.