Improved fluorometric and chromatographic methods for the quantification of fumonisins B1, B2 and B3

Fumonisins pose serious health risks to humans and livestock, making their detection imperative in foods and feedstuffs. This detection can be accomplished quickly, precisely and accurately in a two-step chromatographic process. In the first step, fumonisins are extracted from a sample and isolated on an immunoaffinity column. In the second step, fumonisins are converted to fluorescent derivatives and quantified either through high-performance liquid chromatography (HPLC) or by fluorometer. These methods offer significant improvements in performance compared to earlier technology: limits of detection as low as 0.016 mu g/g with HPLC-based detection and 0.25 mu g/g for fluorometer-based detection; greater assay linearity (with HPLC, r = 0.997; with fluorometer, r = 0.998): larger immunoaffinity column capacity (77% recovery at 12.5 pg) and extended assay range (0-10 mu g/g) for both methods. The percentage recovery of fumonisins over the entire assay range averaged 83% for both the fluorometer and HPLC methods. Precision studies were performed for both the fluorometer and the HPLC methods. The average coefficient of variation was 14% for the fluorometer method and 8.3% for the HPLC method. As a result of the efficient separation, the improved HPLC method offers the advantage of precise individual quantification of FB1, FB2 and FB3. The two methods were compared using 33 naturally or artificially contaminated corn samples. Linear regression analysis demonstrated an excellent correlation (r = 0.996) between the two techniques. Higher recoveries of fumonisins were obtained using this HPLC method than with the official AOAC method. (C) 1998 Elsevier Science B.V. All rights reserved.