Comparison of extraction buffers for the detection of fumonisin B-1 in corn by immunoassay and high-performance liquid chromatography

The Associatian of Official Analytical Chemists approved method for quantification of fumonisin B-1 (FB1) in corn meal or corn-based food products includes extraction into methanol (MeOH)/water (3:1, v/v). Disposal of the extraction medium can pose safety and environmental problems. To secure a rapid and inexpensive screen for FB1 contamination, a sensitive competitive ELISA using a rabbit polyclonal antibody was developed. This assay was used in a comparative study measuring the extraction efficiency of FB1 in aqueous or organic solvent buffers using 16 field corn samples. An aqueous phosphate buffer was found to be suitable for extracting FB1, thus eliminating the need for organic solvents. HPLC and ELISA determinations compared well in fortified samples at known concentrations between 1 and 50 mu g/mL of extract. Overestimation at levels >50 mu g/mL were common. The characteristics and application of the ELISA for screening purposes are discussed.