Determination of Residues of Ochratoxin A and B in Wine by LC-MS/MS

A method of LC-MS/MS was applied to determine residues of ochratoxin A and B in wine. The sample was centrifuged after pH was adjusted. The supernatant was purified using C18 SPE column with methanol as eluent. The eluate was evaporated to dryness by N2 blowing, and the residue was dissolved in 1 mL of mixture of methanol-0.15% (φ) formic acid (7+3) solution. Agilent Eclipse XDB-C18 column was used as stationary phase and the mixture of methanol-0.15% (φ) formic acid (7+3) solution (with 5 mmol·L-1 NH4Ac) was used as mobile phase for elution. ESI and MRM were adopted in MS/MS detection. The linearity ranges of ochratoxin A and B were found below 10.0 μg·L-1, with lower limits of determination (10S/N) of 2.0 μg·L-1. Recovery measured by standard addition method was in the range of 66.3%-87.4% with RSD′s (n=6) in the range of 5.2%-7.6%. The method was applied for the determination of residual of ochratoxin A and B in wine, giving results consistent with that obtained by the AOAC method.