ANALYSIS OF TRICHOTHECENE MYCOTOXINS IN CONTAMINATED GRAINS BY GAS-CHROMATOGRAPHY MATRIX-ISOLATION FOURIER-TRANSFORM INFRARED-SPECTROSCOPY AND GAS-CHROMATOGRAPHY MASS-SPECTROMETRY

Gas chromatography/matrix isolation/fourier transform infrared (GC/MI/ FTIR) spectroscopy and GC/mass spectrometry (MS) were used to confirm the identities of trimethylsilyl (TMS) derivatives of trichothecene my cotoxins in naturally contaminated grains. infrared spectral bands obs erved in the fingerprint region were unique for 10 trichothecene stand ards. Characteristic absorption bands were observed for the ester (nea r 1750 cm(-1)) and ketone (near 1700 cm(-1)) carbonyl stretching vibra tions, the acetate CH3 symmetric bend (1370 cm(-1)), the epoxide ring (1262 cm(-1)), the trimethylsilyl CH3 in-plane deformation (1253 cm(-1 )), the ester (O)C-O asymmetric stretching vibration (near 1244 cm(-1) ), and several other bands including intense features due to the TMS f unction. Infrared bands observed under cryogenic matrix isolation cond itions were compared with those found at room temperature in a potassi um bromide matrix for 5 of these standards. Identities of deoxynivalen ol (DON) from barley and mixed feed, nivalenol from wheat and barley, and DON and fusarenon-x from sweet corn were confirmed by comparison o f their infrared spectral bands with those of standards. The identity of DON in the same test samples of sweet corn was confirmed further by GC/MS. GC/MS was also used to quantitate the levels of DON (67-455 pp m) in sweet corn test samples.