Characterization of (13C24) T-2 toxin and its use as an internal standard for the quantification of T-2 toxin in cereals with HPLC-MS/MS.

In this paper, the structure and the identity of fully 13C-substituted T-2 toxin were confirmed using high-resolution mass spectrometry, 1H-NMR, 13C-NMR, tandem mass spectrometry and HPLC-DAD. The purity of this compound was estimated to be at least 98.8% according to UV data. The isotopic distribution of (13C(24)) T-2 toxin indicated a total isotopic enrichment of 98.2 +/- 1.0 atom% 13C, and the application of different MS measurement modes revealed the MS/MS fragmentation pattern of T-2 toxin. Furthermore, a stable isotope dilution mass spectrometry method for the quantification of T-2 toxin was developed using (13C(24)) T-2 toxin as internal standard. The method was evaluated with and without conventional clean-up and validated for maize and oats. Both cereals showed strong matrix enhancement effects, which could be compensated for through the application of the isotope-substituted internal standard.

Rapid fluorometric test for the quantitative determination of deoxynivalenol in raw cereals.

Fast test systems fulfilling legislative specifications are required to determine mycotoxin contamination in unprocessed cerealse.g. at grain elevators, import and export terminals, or the milling and brewing industry to prevent contamination of food and feed.We describe the first tests of a novel fluorescence-based test for deoxynivalenol (DON), which will be commercially available within the next few months.The analytical procedure of the new test takes less than 15 minutes for extraction, purification, derivatization and measurement. The system's advantage is its speed and easy procedure providing quantitative DON determination.To ensure an international standard, the validation procedure for wheat, barley and maize will be performed following USDA/GIPSA requirements (03/2006) for DON tests.

Improving methods of analysis for mycotoxins: molecularly imprinted polymers for deoxynivalenol and zearalenone.

Selective polymeric phases intended for future use in separation/extraction of deoxynivalenol and zearalenone from beverages have been prepared. Using crystalline deoxynivalenol, zearalenone and quercetin, molecularly imprinted polymers were obtained by a non-covalent imprinting approach via a photo-initiated addition polymerization. Prepared polymers were based on 4-vinylpyridine, methacrylic acid or 2-trifluoromethylacrylic acid as the functional monomer and on ethyleneglycol dimethacrylate, trimethyltrimethacrylate or divinylbenzene as the cross-linking monomer. Selectivity of the generated molecularly imprinted polymers has been investigated by application of the prepared molecularly imprinted polymers as stationary phases in high-pressure liquid chromatography experiments. The retention and elution behaviours of the template compounds and structurally related substances were determined and compared. The results promise future application of molecularly imprinted polymers as alternative selective matrices for clean-up and enrichment of deoxynivalenol and zearalenone.

Synthesis of deoxynivalenol-glucosides and their characterization using a QTrap LC-MS/MS.

Deoxynivalenol (DON)-glucosides were successfully synthesized in a two-step reaction from 1-ß-Bromo-1-deoxy-2,3,4,6-tetra-O-acetyl-α-D-gluco-pyranose and 3-Acetyl-DON or 15-Acetyl-DON. After purification of the reaction products, the mycotoxin conjugates were for the first time characterized by means of a triple quadrupole mass spectrometer in combination with a linear ion trap. Due to different fragmentation behaviour it was also possible to distinguish between the two glucosides.

Fumonisin B1 - Isolation and analytical characterisation for the application as reference material.

A procedure for the production of Fumonsin B1 with a purity of more than 97% has been worked out. The isolated material was characterised by NMR and GC-MS and showed good agreement to literature data, thus proving the identity of the analysed FB1. For the purity assessment with LC-FLD and LC-MS a commercially available standard and the isolated FB1 sample were analysed under the same conditions. The overall purity of the FB1 samples was estimated as 91.9±8.1% (reference) and 97.6±2.4% (biopure), respectively.

Development of enzyme-immunoassays based on egg yolk antibodies for the detection of mycotoxins.

Enzyme-linked immunosorbent assays (ELISA) proved to be a fast and simple method for the detection of mycotoxins and other undesired contaminants in food and feed. The present study is focused on the optimisation and exploitation of the egg yolk antibody technology in order to develop competitive ELISAs for the detection of mycotoxins in cereals. Due to its importance as one of the most relevant Fusarium mycotoxins, the trichothecene deoxynivalenol (DON) was selected as representative. Chickens were immunised with different protein conjugates performing varying booster intervals. The antibodies were isolated by the poly(ethylene glycol) precipitation method according to Polson. By use of these antibodies an indirect competitive ELISA was developed for the detection of DON. First investigations of naturally contaminated wheat samples showed a good correspondence with results obtained by GC-ECD when calibration in blank wheat extracts was performed.