Investigation of alternative reagents to 2-mercaptoethanol for the pre-column derivatization of fumonisins with o-phthaldialdehyde, for HPLC analysis

This paper investigates the suitability of 37 reaction partners for the derivatization of fumonisins with o-phthaldialdehyde (OPA). All resulting fumonisin derivatives were compared for stability by UV-absorption. Subsequently, the relative fluorescence and retention times of derivatives found to be stable in UV-absorption were investigated by high performance liquid chromatography (HPLC), using well-established chromatographic conditions for fumonisin analysis. Several alternatives to 2-mercaptoethanol could be identified to be superior derivatization agents (3-mercapto-propionic acid, N-acetyl-cystein and thioglycerol). Those are especially valid when immunoaffinity column clean up is used prior to derivatization. The structure of the fumonisin B1-derivative obtained from the most suitable derivatization agent N-acetyl-cystein was verified by HPLC-MS.