Reversed-phase liquid chromatographic behavior of the mycotoxins citrinin and ochratoxin A

The reversed-phase (RP) chromatographic behavior of citrinin (CT) and ochratoxin A (OA), the latter introduced as reference substance, were studied as a function of hydrophobicity and silanophilic activities of the stationary phase, pH, type of acid in the eluent, its composition as well as of the column temperature. While OA's affinity to RP materials was not influenced by phase material properties, CT showed a high affinity to hydrophobic phase materials, and its elution order, compared to OA, depended strongly on the phase material chosen. In practice, all octadecyl stationary phases under investigation allowed proper conditions for CT and OA chromatography if judicious selection of influencing parameters, especially a low pH and applying an acid with a pKa<2.3, were chosen.