Evaluation of the extraction and purification procedures of the maleyl derivatization HPLC technique for the quantification of the fumonisin B mycotoxins in corn cultures.

The extraction and purification methods used in the maleyl derivatization HPLC technique was evaluated with respect to the pH of the extraction mixture, the extraction solvent and the purification methods used in order to determine optimum conditions for quantification of fumonisins B1, B2, and B3 in corn cultures. The highest recovery of the three compounds was obtained by extraction at pH 3.5 with CH3OH-H20 (3∶1), whilst the subsequent solvent partitioning and reversedphase C18 Sep-pak purification have been shown to be very important in the quantification of the fumonisins in the corn cultures. The percentage recovery of the improved technique, utilizing a gradient HPLC solvent system for the simultaneous determination of the fumonisins, was 93.4% for FB1, 68.0% for FB2, and 82.6% for FB3. The study indicates that the polarity of the fumonisins and consequently their solubility during extraction as well as their behavior during the subsequent purification step play an important role in quantification of these mycotoxins in corn cultures.