Robotic automated clean-up for detection of fumonisins B1 and B2 in corn and corn-based feed by high-performance liquid chromatography

A high-performance liquid chromatography (HPLC) system with fluorescence detection and an automated on-line solid-phase extraction procedure for fumonisins B-1 and B-2 in corn and com-based products is described. Different amounts of strong anion-exchange, C-18 and end-capped C-18 (C-18 ec) silicas were tested for sample clean-up. Various HPLC parameters were analyzed. The best methodology was found to be extraction with acetonitrile-water and clean up on C-18 ec disposable extraction cartridges. The system has the advantage of running in an unattended mode of operation and allows processing of 40 samples without system refuel, performing clean-up, o-phthaldialdehyde derivatization, injection and fumonisin detection by fluorescence detection linked to a computer integrator for automated data processing. Recoveries were performed with corn and com-based feed samples (n=3) spiked with 0.1, 0.5, 1.0, 5.0 and 10 mug/g. Average recoveries for corn and com-based feed were, respectively, 92.6 and 88.3% with relative standard deviations (RSDs) of 5.04 and 6.22%, for fumonisin B-1 and 91.2 and 89.0% with RSDs of 5.84 and 7.88% for fumonisin B-2,. Detection limits (S/N=3) for corn and com-based feed were approximately 0.03 mug/g for fumonisin B-1 and 0.05 mug/g for fumonisin B-2. (C) 2001 Elsevier Science B.V. All rights reserved.