Electronic Thesis and Dissertation Repository


Master of Science




Dr. Mark Sumarah, Dr. Ken Yeung


Mycotoxins are secondary metabolites produced by fungi, which are harmful to humans and/or animals. Alternaria is a common fungal plant pathogen that can produce mycotoxins in agricultural commodities, such as processed wheat products, and fruit juices. Liquid chromatography mass spectrometry (LC-MS) is commonly used for the detection, characterization and quantitation of mycotoxins in agricultural products. Canadian Alternaria species were assessed to provide a risk assessment of their secondary metabolites in agricultural products by describing their global metabolome data obtained from the Orbitrap LC-MS instrument. Combination of this high mass accuracy data with post data-acquisition analysis techniques resulted in the discovery of new conjugated mycotoxins and secondary metabolites produced by Canadian species of Alternaria.

Data independent acquisition-digital archiving (DIA-DA) was applied as a non-targeted approach for metabolomic profiling of naturally-contaminated silage. DIA-DA allowed for high quality retrospective sample analysis of high resolution LC-MS data with high analyte selectivity.