Simultaneous determination of fumonisin B₁ and B₂ in maize using a facile online pre-column derivatization HPLC...

A rapid, sensitive and reliable analytical method for the simultaneous determination of fumonisin B₁ (FB₁) and fumonisin B₂ (FB₂) was developed and optimised using high performance liquid chromatography and fluorescence detection (HPLC-FLD) coupled with online pre-column derivatization using o-phthalaldehyde (OPA) and 2-mercaptoethanol (2-ME). This study focused on the optimisation of the online pre-column derivatization procedure, HPLC parameters, and sample pre-treatment. FB₁ and FB₂ in maize were extracted and purified using immunoaffinity column (IAC) and derived with OPA at room temperature. The OPA reagent was stable for 7 days, and OPA-derivatised products for 15 min. The excitation and emission wavelengths were 335 nm and 440 nm, respectively. Chromatography was performed using a C18 column and gradient elution at 1.0 mL min^-1 with acetonitrile and 0.1% acetic acid at pH 3.21. The LOD values of FB₁ and FB₂ were 0.10 and 0.26 mg kg^-1, respectively, comparable with or lower than those in other reports. The recoveries of FB₁ and FB₂ were between 85.6%-119.2%. The presented method is time-saving and robust, and successfully applied in determining FB₁ and FB₂ in maize.