Determination of Sixteen Kinds of Polycyclic Aromatic Hydrocarbons in Tea Beverages by MHNTs@ZIF-8-based Magnetic Solid Phase Extraction-Gas Chromatography-Mass Spectrometry
MHNTs@PDA@ZIF-8 with rod-shaped core-shell structures was synthesized and used as sorbent in magnetic solid phase extraction(MSPE).MHNTs@PDA@ZIF-8-MSPE method coupled with gas chromatography-mass spectrometry(GC-MS)was employed to analyze sixteen kinds of polycyclic aromatic hydrocarbons(PAHs)in tea beverages.Vibrating sample magnetometer(VSM),Fourier transform infrared spectroscopy(FT-IR),X-ray diffraction(XRD),scanning electron microscopy(SEM)and nitrogen adsorption-desorption techniques were used to characterize the MHNTs@PDA@ZIF-8.The results demonstrated that the MHNTs@PDA@ZIF-8 exhibited significant magnetic properties and a large specific surface area.The experimental conditions that could affect MSPE were investigated,including adsorbent dosage,extraction time,desorption time,ionic strength,desorption solvent type,and desorption solvent volume.The optimal conditions were 10 mg of MHNTs@PDA@ZIF-8 as adsorbent,90 s under vortex extraction,and ultrasonic desorption for 60 s with 1 mL ofn-hexane.The sixteen kinds of PAHs showed good linearity in the concentration range of 5-500 μg/L(r2≥0.995).The limits of detection(S/N=3)and quantitation(S/N=10)were in the range of 0.1-0.8 μg/L and 0.3-2.6 μg/L,respectively.The recoveries of the method ranged from 60.9%to 114.7%,with relative standard deviations(n=3)ranging from 0.2%to 9.2%when the addition levels of sixteen kinds of PAHs were 10,50,and 100 μg/L.The method was simple,fast,sensitive and environmentally friendly,and suitable for detecting sixteen kinds of PAHs in tea beverages.