Mass Spectral Investigations on Toxins. V. Direct Analysis of Macrocyclic Trichothecenes in Fermentation Samples by Negative Ion Tandem Mass Spectrometric Techniques.
Technical rept. Sep 83-Mar 84,
CHEMICAL RESEARCH DEVELOPMENT AND ENGINEERING CENTER ABERDEEN PROVING GROUND MD
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Due to the extended conjugation in the molecules, macrocyclic trichothecenes formed negatively charged molecular M ions more effectively than positively charged quasi molecular ions under chemical ionization Methane conditions. These M ions underwent collisionally activated dissociation CAD argon yielding the daughter ions characteristic of the macrocyclic ester bridges. Structures for various specific and abundant daughter ions have been proposed and the daughter ions and experimental conditions for selectively detecting these trichothecenes have been selected. A semisynthetic, macrocyclic trichothecene has been found to be adequate as an internal standard for quantifying macrocyclic trichothecenes under CAD conditions. Low quantities 1 to 2 ng of Roridin H and Satratoxins have been detected under these same conditions. Preliminary results indicate that the negative ion chemical ionization-mass spectrometrymass spectrometry method can be applied to analyzing real-life samples. Keywords Toxins argon gas Mycotoxins Negative ions Chemical ionization Tandem mass spectrometry Collisionally activated dissociation Mass spectroscopy.