Determination of polycyclic aromatic hydrocarbons in coffee and tea samples by magnetic solid-phase extraction coupled with HPLC-FLD.

This study reports the synthesis of a benign nano-adsorbent based on an ionic liquid of immobilized Fe3O4@3-(Trimethoxysilyl)propyl methacrylate@ionic liquid magnetic nanoparticles (Fe3O4@MPS@IL NPs). This material was applied to the magnetic solid phase extraction of seven heavy molecular weight polycyclic aromatic hydrocarbons (PAHs) from coffee and tea samples for high performance liquid chromatography coupled with fluorescence detection. The effects of various parameters of the analytical method were investigated, including pH, sorbent amount, desorption solvent, desorption volume, and extraction and desorption time. Under the optimized conditions, good linearities were obtained, with correlation coefficients (R(2)) between 0.9987 and 0.9998. The detection limits of the proposed method were in the range of 0.1-10ngL(-1). The spiked recoveries of the seven PAHs in coffee and tea samples ranged from 87.5% to 104.5%, with RSDs of less than 3.7%. In addition, a satisfactory reproducibility was achieved, with intra- and inter-day precisions with RSDs of less than 3.1% and 3.8%, respectively.