ANALYSIS OF CANADIAN AND IMPORTED BEERS FOR FUSARIUM MYCOTOXINS BY GAS-CHROMATOGRAPHY MASS-SPECTROMETRY

A sensitive method was developed for the determination of deoxynivalen ol (DON), nivalenol (NIV), alpha-zearalenol (alpha-ZEL), beta-zearalen ol (beta-ZEL) and zearalenone (ZEN) in beer by capillary gas chromatog raphy-mass spectrometry (GC-MS) of their heptafluorobutyrate (HFB) der ivatives. Recoveries averaging 90-103% were obtained from beers spiked with each mycotoxin in the 5-20 ng/ml concentration range. Limits of detection were 0.1-1.5 ng DON/ml, 0.01-0.3 ng NIV/ml, 2.5-3 ng alpha- and beta-ZEL/ml, and 1.5-2 ng ZEN/ml. Twenty-nine of 50 samples of Can adian and imported beer surveyed were found to contain DON; of these n ine contained greater than 5 ng/ml (up to 50 ng/ml). The identity of D ON was confirmed by response ratios at m/z 670 and m/z 884 for the HFB derivative and m/z 497 and m/z 512 for the trimethylsilyl (TMS) deriv ative. NIV was also detected in three beer samples (0.1-0.84 ng/ml) bu t no alpha-ZEL, beta-ZEL or ZEN was found