Mass spectrometric evidence for demethylated homologs occurring at trace levels in trichothecene standards.

Compounds with molecular weights 14 a.m.u. lower than their corresponding parent compounds have been detected in trichothecene standards during gas chromatography-mass spectrometry analysis. The positive ion chemical ionization mass spectra indicated that these compounds were trichothecene homologs lacking a methyl group on the isovaleroxy substituent at the C-8 position. Demethylated derivatives have been found in the standards of T-2, HT-2, and T-2 triol prepared in our laboratory and those obtained from a commercial source.