Quantitation of fumonisin B1 and B2 in feed using FMOC pre-column derivatization with HPLC and fluorescence detection

- FMOC-derivatized fumonisin calibrants experience no fluorescent decay over 7 days.
- Immunoaffinity SPE clean-up eliminated matrix effects in corn-based feed extracts.
- Quantitative results indicate FMOC-Cl is a suitable alternative reagent to OPA.

Pre-column derivatization with 9-fluorenylmethyl chloroformate (FMOC-Cl) was determined to be effective for quantitation of fumonisins B1 and B2 in feed. Liquid-solid extraction, clean-up using immunoaffinity solid phase extraction chromatography, and FMOC-derivatization preceded analysis by reverse phase HPLC with fluorescence. Instrument response was unchanged in the presence of matrix, indicating no need to use matrix-matched calibrants. Furthermore, high method recoveries indicated calibrants do not need to undergo clean-up to account for analyte loss. Established method features include linear instrument response from 0.04-2.5 µg/mL and stable derivatized calibrants over 7 days. Fortified cornmeal method recoveries from 0.1-30.0 μg/g were determined for FB1 (75.1%-109%) and FB2 (96.0%-115.2%). Inter-assay precision ranged from 1.0%-16.7%. Method accuracy was further confirmed using certified reference material. Inter-laboratory comparison with naturally-contaminated field corn demonstrated equivalent results with conventional derivatization. These results indicate FMOC derivatization is a suitable alternative for fumonisins B1 and B2 quantitation in corn-based feeds.