Liquid chromatographic determination of fumonisins B1 and B2 in corn samples after reusable immunoaffinity column clean-up

The possibility of the liquid chromatographic determination of fumonisins B1 (FB1) andB2 (FB2) in corn samples with a reused immunoaffinity column (IMA) for the clean-up of the samples was investigated. After optimization of the chromatographic determination of FB1 and FB2 derivatized with o-phthaldialdehyde- 2-mercaptoethanol, the efficiency of the clean-up of spiked corn extracts with reuse of the IMA columns was studied, both with and without column regeneration. It was found that the IMAcolumn, designated for single-use only, can be used at least five times without regeneration and additional five times after regeneration. Regeneration consists of leaving the phosphate buffer saline solution on the column for one day at 4 ºC. The efficiency of the columns was tested by determining the recovery of FB1 and FB2, as well as the reproducibility of the determinations. The mean recoveries of FB1 and FB2 from corn spiked with FB1 at 1.0 mg/g and with FB2 at 0.5 mg/g (on the basis of 10 measurements) were 88.7%(RSD 10.2%) and 90.5%(RSD 6.1 %), respectively