Abstract:A rapid method for the determination of ochratoxin A in Chinese medicinal plants using ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) was established in this study. For this method, the conditions required for liquid chromatography (LC) and mass spectrometry (MS) were optimized and the matrix effects were overcome by extraction using sodium bicarbonate solution and dilution procedure. The ultrasonic-assisted extraction of ochratoxin A from the sample was carried out using sodium bicarbonate solution, followed by an immunoaffinity column clean-up procedure. The analytes were separated on a C18 LC column and detected on a mass spectrometer operating in the positive ion multiple reaction monitoring (MRM) mode. The method used in the present study was validated. Ochratoxin A concentration showed good linearity in the range of 0.1~50.0 μg/L, with an r-value>0.99. The average recoveries ranged between 78.5% and 98.0% at spike levels of 1.0, 2.0, and 10.0 μg/kg. The relative standard deviations (RSDs) were between 2.6% and 11.8%, and the limit of detection was 1.0 μg/kg. The validated method was applied for the detection of ochratoxin A in eight batches of samples, and the results showed one positive result per batch (7.3 μg/kg). The results of the real sample test indicate that this method can be used for the sensitive and accurate determination of ochratoxin A in Chinese medicinal plants.
