UBC Theses and Dissertations
Designing separation systems in capillary electrophoresis based on the fundamental physicochemical properties of analytes Britz-McKibbin, Philip
This thesis strives to develop an integrative approach towards separation design in capillary electrophoresis (CE) based on the fundamental physicochemical properties of analytes. It is divided into four main sections to deal with four important aspects of separation design in CE which include theory, selectivity, assay development and sensitivity. The use of additives in CE represents one of the most powerful ways to separate analytes in a mixture, since both electric field (mobility) and equilibria (affinity) are used in the separation process. Section A developed a theory to describe the migration behaviour of analytes in CE when using additives in the run buffer. The mobility of an analyte can be predicted at any additive concentration, capillary length, or voltage for rapid and systematic optimization of separation conditions. Section B involved the synthesis, characterization and application of TESMR, a water-soluble aromatic based macrocycle, as a new type of additive in CE. Separation of neutral species is accomplished by imparting an electrophoretic mobility to the analytes via differential complexation with TESMR. The development and validation of two different quantitative assays by CE is presented in Section C. A simple and sensitive method to analyze the γ-carboxyglutamic acid content of protein, urine and plasma is developed using CE with laser-induced fluorescence detection. The second assay involved the development of a robust method for the quantification of epinephrine in fifteen different dental anesthetic solutions. Selective on-line focusing of analytes using a discontinuous electrolyte system is presented in Section D as a facile way to improve concentration sensitivity in CE when using UV detection. Large volumes of a dilute sample can be focused into extremely sharp zones by carefully selecting appropriate sample and background electrolyte conditions. A summary of the results of the thesis and possible future endeavours is also discussed, as well as an integrative framework towards separation design in CE.
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