Determination of ochratoxin A in Hungarian wines

Determination of ochratoxin A (OA) in musts and wines is described using high performance liquid chromatography with fluorescence detection (HPLC-FL). The applicability of common solid phase extraction cartridges with octadecyl-silica stationary phase (C18-SPE) instead of immunoaffinity columns (IAC) for sample clean-up and preconcentration of OA is discussed. Utilizing 100-fold concentration, the detection limit and quantification limit of OA in wine were 0.024 and 0.125 ng/ml, respectively. Mean recovery amounted to 83.5%. Confirmation of the presence of OA was performed by quantitative conversion of OA into its methyl ester with BF3/methanol. The method was successfully applied to routine analysis of 87 Hungarian must and wine samples. The method proved to be robust during the 2 weeks of routine measurements resulting in a mean recovery of 99.4% (std. dev. 2.4%, n=11) related to the first measurements on the control sample. OA was not detectable in the Hungarian wine and must samples.