Determination of ochratoxin A in wolfberry fruit wine with high performance liquid chromatography-tandem mass spectrometry

ObjectiveTo develop a sensitive and accurate method of high performance liquid chromatography-tandem mass spectrometry for the quantification of ochratxoin A(OTA)in wolfberry fruit wine.MethodsSamples were cleaned up by immunoaffinity column(IAC)and then separated on Agilent Zorbax SB-C₁₈ column(2.1 mm×50 mm, 3.5μm).Gradient mobile phase was prepared with water(containing 0.1% formic acid)and acetonitrile(containing 0.1% formic acid).Flow rate was set to 0.4 mL/min and the injection volume was 10μL.Liquid chromatography-electrospray ionization-MS/MS(LC-ESI-MS/MS)in multiple reaction monitoring(MRM)was operated under positive electrospray ionization mode.ResultsThe limit of quantification(LOQ)of the method was 0.02 ng/mL.The calibration curves showed a good linearity in the range of 0.02-20 ng/mL.The spiked levels were set at 0.2,2,and 20 ng/mL with the average recoveries of 71.0%,83.7%,and 86.0% and the relative standard deviations(RSDs)of 8.0%,9.0%,and 6.1%,respectively.OTA concentrations in the 12 samples investigated were between 0.03 ng/mL and 0.18 ng/mL,and the detection rate was 50.0%.ConclusionOTA concentrations in the samples investigated were all below the maximum allowable limit established by the European Community.The method was proved to be simple,rapid,sensitive,and suitable for the quantification of OTA in wolfberry fruit wine.