Analysis of ochratoxin A in pig kidney and rye flour using liquid chromatography tandem mass spectrometry (LC/MS/MS)

A liquid chromatography electrospray tandem mass spectrometric (LC/MS/MS) method is described for analysis and confirmation of ochratoxin A in pig kidney and rye flour using derivatization of ochratoxin A to the methyl ester. Ochratoxin A methyl(d₃)ester is used as internal standard. The method works well, the detection limit is 0.02 μ g/kg and the repeatability (coefficient of variation) is between 6% and 16% in the contamination range 0.5 to 8 μ g/kg.