Rapid and high resolution capillary supercritical fluid chromatography (SFC) and SFC/MS of trichothecene mycotoxins

The potential application of capillary column supercritical fluid chromatography (SFC) and SFC/mass spectrometry (SFC/MS) for the separation and analysis of mycotoxins of the trichothecene group was examined. Trichothecenes present significant analytical problems for both gas and liquid chromatography with a major difficulty for the latter being the lack of sufficiently sensitive and selective detectors. Supercritical carbon dioxide mobile phases at temperatures up to 100 degrees C were used with deactivated fused silica columns coated with crosslinked stationary phases. Separations were obtained under pressure ramped conditions using long (15 m) 50-micron i.d. columns for several trichothecenes (diacetoxyscirpenol, deoxynivalenol, and T-2 toxin) and related higher molecular weight macrocyclic (roridin and verrucarin) trichothecenes. In addition, new rapid pressure programming techniques with short (less than 2m) 25- to 50-micron i.d. capillary columns were used to obtain fast separations in as little as 1 min. SFC/MS with ammonia chemical ionization provided high selectivity and sensitive detection (with approximately 1-pg detection limits) for trichothecene mixtures. The extension to complex sample matrices is discussed and the application of selective MS/MS detection is demonstrated.