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Capillary electrophoresis-mass spectrometry and complementary approaches for semi-quantitative analysis of samples with complex matrices

University of British Columbia

Capillary electrophoresis-electrospray ionization-mass spectrometry (CE-ESI-MS) combines the superior separation efficiency of CE with the detection capability of MS to provide information-rich data on samples with complex matrices. CE-ESI-MS is applied to a range of complex mixtures to semi-quantify unknown components and find patterns among groups of samples. The first part of this thesis tells how the industrial generation of oil sands process-affected waters (OSPW) poses an environmental threat, and a review is given on the state-of-the-art of analytical chemistry in the semi-quantification of toxic naphthenic acid fraction compounds (NAFC) in OSPW. The chapter ends with a technical description of the CE-ESI-MS system which was utilized. CE-ESI-MS was demonstrated to produce effective analyses of a well-known complex mixture: human urine. CE-ESI-MS was used to quantify and “fingerprint” components in human urine via targeted and untargeted analyses of the sub-5 kDa urine metabolome of patients with prostate and/or bladder cancer. For targeted analysis, endogenous levels of sarcosine and 5 other metabolites were quantified in four patients and in a pooled healthy urine sample. An untargeted analysis of patient urine was also performed identifying over 400 distinct molecular features per patient. Next, a CE-ESI-MS method was developed for the analysis of a relatively unknown complex mixture: NAFCs in OSPW. A standard mixture of amine-derivatized naphthenic acids was analyzed in under 15 min, detecting NAFCs between m/z 250 and 800. Derivatization of NAFCs consisted of two-step amidation reactions mediated by 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) and N-hydroxysuccinimide in three different solvents. The optimum BGE composition was determined to be 30% (V/V) methanol in water and 2% (V/V) formic acid. The optimized CE-ESI-MS method was then used to find patterns in NAFCs across porewater samples impacted by oil sands waste. CE-ESI-MS, Orbitrap MS, and a standard GC-FID method were used to characterize porewater samples. Differences in measured amounts of total petroleum hydrocarbon by GC-FID and NAFC by HRMS indicate that the two methods provide complementary information about dissolved organic species in water leachate samples. CE-ESI-MS also provides complementary information and is a feasible and practical option for source evaluation of NAFCs in water.

Text

2018-09-05

Attribution-NonCommercial-NoDerivatives 4.0 International

http://hdl.handle.net/2429/67116

Chemistry

University of British Columbia

UBCV

http://creativecommons.org/licenses/by-nc-nd/4.0/