Effect of extraction and extract purification on the measurable fumonisin content of maize and maize products. Tests on the efficiency of acid extraction and use of immunoaffinity columns.

The extraction of naturally contaminated maize-based products using methanol / water (3+1) or methanol / 0.1 M hydrochloric acid (3+1) produced varying results. Compared with methanol / water extraction tested in IUPAC/AOAC intercomparison studies, as a rule acid extraction achieves a higher fumonisin content. Strong anion exchange columns are very effective for the analysis of untreated maize, such as maize grits or maize meal. This method guarantees satisfactory extract purification. In products with a high fat content (such as maize based snack products) or cornflakes, SAX columns were not particularly effective. For there immunoaffinity columns provide a highly selective extract purification and achieve a very pure chromatogram. Immunoaffinity columns were also used on cornflakes as they achieved better results than the SAX columns.