Identifying and Quantifying Molecular Species in Biological Samples Using a Multimodal Mass Spectrometry Approach

Mass spectrometry is a versatile analytical tool that can identify, quantify, and even localize an analyte in biological samples. Mass spectrometry has a plethora of applications, but it is often underutilized in fields outside of analytical chemistry. Through optimized method development and utilization of other techniques, multidisciplinary results can be obtained. Cattle fever ticks pose an impending threat to the United States. Through mass spectrometry, current approved macrocyclic lactone-based drugs are quantified using electrospray ionization liquid chromatography tandem mass spectrometry (ESI-LC/MS/MS). The results are used to make recommendations concerning interactions, and efficacy. Additionally, novel drug-targets are probed though matrix-assisted laser desorption/ionization time-of flight mass spectrometry imaging (MALDI-TOF MSI). Peptides are localized and identified on intact tissue sections of cattle fever ticks. The methodology allows for interspecies comparisons, and investigation into mechanisms for drug-resistance. Mass spectrometry can be applied to analysis of other biological matrices. Fatty acid content in skin, and plasma samples can be quantified, and correlated to self-reported pain. The higher the omega-6 fatty acid content, the more sensitive one is to external stimuli. Therefore, the ratio of omega-6 to omega-3 fatty acids are shown to influence pain mechanism pathways, and may contribute to comorbid pain conditions, such as diabetic neuropathy. Aged, dried blood spots contain viable information but are often overlooked. Through optimized sample prep, proteins can be extracted and identified. This provides a baseline for comparison to changes in protein compositions after potential diseases progression. This work bridges the gap between multiple disciplines for more rounded research.