Submitted to: Chromatographia
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/20/1997
Publication Date: N/A
Interpretive Summary: The detection of mycotoxins in agricultural products requires the development of ultra-sensitive methods due to the occurrence of these toxicants at trace levels in matrices such as grains, meats, or peanuts. Usually the methods to extract these toxicants require copious amounts of flammable and toxic extraction solvents and are non-specific with respect to the targeted toxicant. In this study, a particular mycotoxin called deoxynivalenol (DON) has been extracted using pressurized carbon dioxide as the extraction "solvent", coupled with low levels of conventional liquid solvents to accelerate the removal of the DON from oats and wheat. Although the extraction conducted with carbon dioxide is successful, the presence of a large quantity of unwanted, coextracted components limits the usefulness of the technique. We have coupled the high pressure gas extraction technique with methods that "cleanup" the sample extract, so that the DON moiety can be analyzed quantitatively. The most effective cleanup techniques included defatting the extract with an addition of a solvent, or alternatively, using various types of cleanup columns, which either hold back the coextracted oil/fat or permit isolation of the DON. The techniques developed in this study appear to show promise for making analysis of these trace compounds easier, as well as allowing their implementation in food processing plants where there is a need for an environmentally compatible, rapid qualitative assay for DON.
Technical Abstract: Deoxynivalenol (DON) is one of the trichothecene mycotoxins produced by Fusarium molds in grains. Polar cosolvents in supercritical carbon dioxide (SC-CO2) are needed to extract and isolate the polar DON moiety. This unfortunately results in the extraction of many interfering compounds from the grains into the extracts obtained by supercritical fluid extrcation (SFE). Analysis of DON by high performance liquid chromatography (HPLC) using ultraviolet detection (UV) does not provide a specific detection method, although specific detection of DON can be enhanced by using purification steps after SFE. Alternatively, combining SFE with an immunoaffinity method can improve detection specificity and sample cleanup. In this study, SFE was employed to determine DON in grains and cereal products. The effectiveness of the SFE method was compared with two different solvent extraction methods. The extracted DON was quantitatively determined by HPLC-UV using external standardization or competitive enzyme-linked immunosorbent assay (ELISA). In some cases, extracts were purified prior to quantitative analysis of the DON by using solvent partitioning, and/or solid phase extraction, or immunoaffinity columns. Therefore, this paper describes the analysis of DON in cereals using different extraction, cleanup and analysis methods.