Determination of 5 Mycotoxins in Fruit Juices and Fruit Wines by Ultra-High Performance Liquid Chromatography-Tandem Mass Spectrometry Combined with QuEChERS

An aliquot (2 g) of the sample was taken, and 15 mL of 10% (volume fraction) acetonitrile solution was added. The mixture was extracted for 30 min by vortex, and QuEChERS salt package (containing 4 g of anhydrous magnesium sulfate and 1 g of sodium chloride) was added. The mixture was vortexed for 1 min, and centrifuged for 5 min. An aliquot (500 μL) of the supernatant was taken, and mixed with 500 μL of 10% (volume fraction) methanol solution by vortex. The solution was introduced into the ultra-high performance chromatograph-tandem mass spectrometer. Five mycotoxins, including mycophenolic acid (MPA), penicillic acid (PA), citrinin (CIT), penicillium citreoviride (CTV) and roquefortine C (ROC), were separated on the Thermo Acclaim RSLC C₁₈ column by gradient elution with mixed solutions composed of methanol and 0.1% (volume fraction) formic acid solution at different volume ratios, ionized by the ESI⁺ mode, detected by the MRM mode, and quantified by the matrix matching method. It was shown that linear relationships between values of the mass concentration of the 5 mycotoxins and the corresponding peak area were kept in definite ranges, with detection limits (3S/N) in the range of 0.3-5.0 μg·kg^-1. Test for recovery was made according to standard addition method, giving recoveries in the range of 81.1%-105%, and RSDs (n=6) of the determined values ranged from 0.63% to 5.9%. The proposed method was applied to the analysis of 41 batches of fruit juice samples and 59 batches of fruit wine samples from the market. PA (2 batches), MPA (1 batch) and CTV (1 batch) were detected in fruit juice samples, with detection amounts of 137, 52.6 μg·kg^-1 for PA, 2.92 μg·kg^-1 for MPA and 2.81 μg·kg^-1 for CTV; and PA (1 batch) and MPA (2 batches) were detected in fruit wine samples, with detection amounts of 34.3 μg·kg^-1 for PA and 3.51, 2.94 μg·kg^-1 for MPA.