Determination of Fungicides in Fresh Fruit Juice Using Magnetic Solid-Phase Extraction Coupled With Gas Chromatography–Triple Quadrupole Mass Spectrometry

A fast, simple and effective method was developed and validated for determination of 11 fungicides using magnetic solid-phase extraction with NH2-Fe3O4@GO (graphene oxide) combined with gas chromatography–triple quadrupole mass spectrometry (GC–MS/MS). To carry out the extraction of the fungicides from samples, NH2-Fe3O4@GO nanocomposites were synthesized and characterized by scanning electron microscopy, Fourier transform infrared spectroscopy and X-ray diffraction. The target analytes were extracted on NH2-Fe3O4@GO and then eluted by ethyl acetate and acetonitrile (1:1 v/v). Finally, the extraction solvent concentrated by nitrogen blowing was analyzed by GC–MS/MS, which demonstrated good linearity between 0.05 and 5.0 mg L−1. The limits of detection (signal-to-noise ratio = 3) and the limits of quantification (signal-to-noise ratio = 10) for the 11 fungicides ranged from 1.0 to 3.5 and 3.0 to 10.5 μg kg−1, respectively. The accuracy and precision of the proposed method were evaluated by measuring tagged samples; the recoveries and relative standard deviations ranged from 75.3% to 103.9% and 2.19% to 4.68%, respectively. The utility of the adsorbent was demonstrated to determine trace fungicides in fresh fruit juice samples.