Certification of the aflatoxin B1 content in animal feed Reference Materials and intercomparison with supercritical fluid extraction (SFE)

Performance of modern sample preparation techniques in the analysis of Fusarium mycotoxins in cereals

The efficiency of modern sample preparation techniques are discussed and compared to well-established techniques with respect to the determination of zearalenone in corn and B-trichothecenes in wheat in the microgram/kg range. This includes the use of immuno-affinity columns and of multifunctional Mycosep columns as well as the employment of supercritical fluid extraction for the trace analysis of these major Fusarium mycotoxins. In addition, the performance of new analytical methods was investigated in an interlaboratory comparison study only recently organized by our laboratory. From both the validation data, and from the results of the intercomparison study, the suitability and competitiveness of the described methods could be clearly demonstrated.

Determination of trichothecene mycotoxins in wheat by use of supercritical fluid extraction and high-performance liquid chromatography with diode array detection or gas chromatography with electron capture detection

The extraction behaviour of the Fusarium mycotoxin deoxynivalenol (DON) and some related type B trichothecenes from spiked seasand, spiked wheat flour and naturally contaminated wheat flour with modified supercritical CO2 has been investigated and optimized under several conditions. The extraction fluid was decompressed over a solid-phase trap and the amount of deposited analytes was determined by HPLC-diode array detection (DAD) or GC-electron capture detection (ECD) without any further clean-up. Recovery rates as high as 90.1 +/- 10.7% were achieved for spiked wheat samples and 53.0 +/- 3.2% for naturally contaminated samples. The performance of the optimized supercritical fluid extraction (SFE) method was compared with an already well established analytical method employing extraction on a rotary shaker in combination with Mycosep clean-up. Moreover, the SFE procedure developed for naturally DON contaminated wheat was employed for the simultaneous extraction of 5 type B trichothecenes by GC-ECD. This work represents the first successful approach in obtaining an SFE-method for the extraction of Fusarium mycotoxins from wheat with reasonable recoveries and good precision.

BCR- and M&T-activities in the area of mycotoxin analysis in food and feedstuffs

In order to avoid undesirable side effects such as high contents of mycotoxins in food and feed, measurements at critical steps of the food and feed production chain are performed. These measurements need to be accurate and precise to satisfy these aims. The accuracy and precision requirements to measurements form the basis of the Bureau Communautaire de Référence (BCR)-and Measurements and Testing (M&T)-Projects. Such projects aim to improve and/or develop analytical methodology, sampling plans, to harmonise agreement of results between European Union Member States and to prepare suitable certified reference materials (CRMs). The selection of the matrix CRMs and their corresponding level of mycotoxin contamination is made on the basis of requirements of the applied analytical procedures, stability requirements, regulations, norms, and inter-or intra-trade agreements which are in relation to quality specifications of imported and/or exported goods. The availability of appropriate matrix CRMs is not only a prerequisite for the implementation of directives and norms. It allows the validation of new methods and provides a possible solution to trade disputes, means for the statistical control of analytical results, tools for laboratory accreditation, and it is the basis for harmonisation and traceability of proficiency schemes.