Abstract:A method for the determination of five mycotoxins in fermented Pu'er tea, and Hunan dark tea and black tea samples was established. Ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was used to identify aflatoxin B1 (AFB1), aflatoxin B2 (AFB2), aflatoxin G1 (AFG1), aflatoxin G2 (AFG2), and ochratoxin A (OTA) under the multiple reaction monitoring (MRM) mode. Tea samples were extracted with an acetonitrile/water solution (84 / 16), and purified using a MycoSpin 400 multifunctional clean-up column. Samples were separated on an Agilent Zorbax Rrhd SB-C18 column (2.1 mm ? 100 mm, 1.8 μm), and qualitative and quantitative analyses were performed using MRM mode. Quantitation was conducted using the external standard method. The results indicated that, under the optimal conditions, five mycotoxins showed a good linear relationship within their own linear response range, with correlation coefficients (r) more than 0.9983, and limits of quantification (LOQ) ranging from 0.1 to 0.5 μg / kg. The recovery of the five mycotoxins at low, medium, and high spiking levels ranged from 63.5% to 125.0%, and the relative standard deviation (RSD, n=3) values were between 3.9% and 17.2%. This method has a simple pretreatment, can provide rapid detection, good purification, and accurate and reliable results, and is suitable for the rapid detection of multi-component mycotoxin contaminants in fermented tea.
