The Column - April 2007 - (Page 8)

Korte, Erwine and Wood The Column www.thecolumn.eu.com April 2007 Improved Isolation and Analysis of Mycotoxins from Cereals, Beer and Wine 1Varian Elisabeth Korte,1 Max Erwine2, Jason S. Wood2 and Mahalakshmi Rudrabhatla2 Deutschland GmbH, Darmstadt, Germany, 2Varian Inc., Palo Alto, California, USA. This article describes a novel extraction sorbent used to analyse naturally occurring 12 trichothecenes and polar mycotoxins. Fusarium fungi are probably the most prevalent toxin-producing fungi of the northern temperate regions and are commonly found on cereals grown in the temperate regions of America, Europe and Asia. A variety of these fungi produce different toxins in the trichothecenes class. More than 140 of these compounds have been isolated from fungal cultures and this number is still increasing.1 The toxic effects of fusarium metabolites on human and animals are well-documented and reliable and sensitive analysis methods are therefore required to protect the population and its food sources.2,3 Traditional sample preparation for trichothecene analysis typically involves extraction with acetonitrile/water and clean-up via charcoal–alumina columns.4 As the trichothecenes differ considerably in polarity and solubility, recoveries of the more polar analytes are often compromised. Another approach is the use of immunoaffinity columns (IAC)5 which provide highly selective extractions with high recoveries, but require separate IAC columns for each toxin. To overcome the limitations of these methods there is a need to develop an extraction and clean-up method for the simultaneous determination of several trichothecenes with high recoveries for the polar toxins by minimizing the matrix effects. This application shows the optimized extraction and clean-up of 12 type A- and -B-trichothecenes and zearalenone (ZEA) in cereals and cereal-based food (Figure 1), as well as four polar Authors: Korte, Erwine and Wood E-mail: elisabeth.korte@varianinc.com mycotoxins, deoxynivalenol (DON), T-2 toxin (T-2), HT-2 toxin (HT-2) and zearalenone (ZON ), in wheat beer and sake wine matrices. The clean-up was optimized on Bond Elut Mycotoxin (Varian, Palo Alto, California, USA) a newly developed solid phase extraction (SPE) sorbent. The liquid chromatography–mass spectrometry–mass spectrometry (LC–MS–MS) method presented in this paper gives quantitative and qualitative information and has the accuracy and resolution required for reporting results to European and US governmental agencies.6 Sample Preparation Cereals and cereal-based food samples: Typical clean-up methods of trichothecenes and ZEA from cereals and cereal-based foods use commercially available polar clean-up columns. In this way, substances that interfere with the detection of the mycotoxins are retained while trichothecenes are not. This purification method, however, gives low recoveries for the polar toxins, nivalenol (NIV), T-2 tetraol, and DON. New studies point out that one possible reason for the low recoveries of the polar toxins might be the low water content in the acetonitrile/water mixture (ACN/H2O, 84/16 v/v), which is used for the extraction of mycotoxins from the matrix.7 Furthermore, to elute these polar compounds from a column packed with polar adsorbents such as alumina, a hydrophilic 8 http://www.thecolumn.eu.com

Table of Contents for the Digital Edition of The Column - April 2007

Contents
News
Improved Isolation and Analysis of Mycotoxinsfrom Cereals, Wines and Beers
Zosimus
Pittcon 2007 Review
Trace-Level Determination of Bromate in Waterby Ion Chromatography
Q&A

The Column - April 2007