Determination of fumonisins in corn: Evaluation of two purification procedures.

The performance of two solid phase extraction (SPE) purification procedures, used in the determination of fumonlsin B1 (FB1), B2 (FB2) and B3 (FB2) In corn, was evaluated using both thin-layer chromatography (TLC) and high performance liquid chromatography (HPLC). Fewer interferences were observed In extracts prepared using the strong anion exchange (SAX) media, in contrast to those purified on C18 media, where on occasions, visual discernment of the TLC bands was hampered by the presence of interfering compounds. Precipitate formation, resulting In the blocking of SPE cartridges was also encountered when using the C18 procedure. HPLC analyses of extracts prepared by both media indicated that they gave comparable fumonlsin recoveries from naturally contaminated corn samples. The results suggest that the C18 procedure, originally developed for the TLC analyses of FB1 in mixed feeds, may also be applied to the determination of FB2 and FB2. However, where TLC is used quantitatively for fumonlsin levels <1 μg/g, purification of sample extracts on SAX media is recommended.