<p>Mass spectrometry (MS)
alone or coupled with high-performance liquid chromatography (HPLC) or gas
chromatography (GC) is a versatile analytical tool that is routinely employed
for identification of unknown compounds in complex mixtures. MS operates by separating
ionized analytes based on their mass-to-charge (<i>m/z</i>) ratios. If the analyte can be ionized without complete
fragmentation, MS provides molecular weight information and, if performed at
high resolution, elemental compositions for the ionized analytes. Tandem mass
spectrometry (MS<sup>n</sup>, n <u>></u> 2 where each MS step corresponds to
an ion isolation or separation event) also provides structural information of
ionized analytes. With this approach, structural information of the ionized
analytes is obtained by isolating the ionized analytes of interest and
subjecting them to fragmentation experiments, such as collision-activated
dissociation (CAD). The ions of interest can also be isolated and allowed to
react with gaseous molecules to generate product ions (ion-molecule reactions).
</p>
The
experiments described in this dissertation focused on the development of tandem
mass spectrometry methods based on CAD and/or gas-phase ion-molecule reactions
for the differentiation of acyl, <i>N</i>-
and <i>O</i>-glucuronide drug metabolites
and for identification of primary carbamates as potentially mutagenic
impurities. Further, by using a previously published method titled Distillation, Precipitation,
Fractionation Mass Spectrometry (DPF MS), the chemical compositions of
five crude oil samples, including heavy, medium, and light crude oils with
different API gravities, were determined. Additionally, the gravimetric
percentages of different compound classes found in these crude oils are
reported as well as the correlations found between
API gravities and the chemical compositions of crude oils.
| Identifer | oai:union.ndltd.org:purdue.edu/oai:figshare.com:article/8937986 |
| Date | 15 August 2019 |
| Creators | Edouard Niyonsaba (6953621) |
| Source Sets | Purdue University |
| Detected Language | English |
| Type | Text, Thesis |
| Rights | CC BY 4.0 |
| Relation | https://figshare.com/articles/DEVELOPMENT_OF_MASS_SPECTROMETRIC_METHODS_FOR_FAST_IDENTIFICATION_OF_DRUG_METABOLITES_AND_FOR_DETERMINATION_OF_THE_CHEMICAL_COMPOSITIONS_OF_CRUDE_OILS_OF_DIFFERENT_API_GRAVITIES/8937986 |
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