A Novel pH-adjusted Water Stationary Phase for Capillary Gas Chromatographic Separations
| dc.contributor.advisor | Thurbide, Kevin B. | |
| dc.contributor.author | Darko, Ernest | |
| dc.contributor.committeemember | Kimura-Hara, Susana | |
| dc.contributor.committeemember | Gailer, Jürgen G. | |
| dc.date | 2019-06 | |
| dc.date.accessioned | 2019-04-15T14:47:00Z | |
| dc.date.available | 2019-04-15T14:47:00Z | |
| dc.date.issued | 2019-04-11 | |
| dc.description.abstract | In this thesis, a novel pH-adjusted water stationary phase coated on a stainless steel column was investigated, characterized, and compared to other conventional columns in capillary gas chromatography (GC). The pH-adjusted water stationary phase was applied to the analysis of both organic bases and acids. The analysis of organic bases and acids on a regular pH 7 water phase is impossible to achieve due to the poor peak shapes and elution properties that result. However, these compounds readily eluted and separated well when pH 11.5 and 2.2 water stationary phase coatings are employed respectively. In the basic and acidic conditions, analytes are neutralized and are observed to produce good peak shapes even for analyte masses down to about 5ng. By comparison, analyses on a conventional non-polar capillary GC column yield more peak tailing and only analyte masses of 1 μg or higher are normally observed. Through carefully altering the pH, it is found that the selectivity between analytes can be potentially further enhanced if their respective pKa values differ sufficiently. The analysis of different pharmaceutical and petroleum samples containing organic bases and acids are demonstrated and are neatly simplified and improved using the pH-adjusted water stationary phase. Separations are also quite reproducible and provide low RSD values for the developed technique. In related work, a dynamic stationary phase switching technique was also studied and characterized for use in analytical separations involving complex mixtures. The study showed the ability to dynamically and externally control ionisable analyte retention and selectivity in GC. By first trapping these analytes, they could later be eluted on demand. Accordingly, organic bases and acids were reproducibly analyzed with much improved selectivity and resolution over other compounds. Further, by employing a triple column system, it was demonstrated that separation of hydrocarbons in complex matrices such as gasoline was achieved alongside a similar selective analysis of organic bases/acids. These results for organic acids and bases indicate that the use of a pH-adjusted water stationary phase approach can potentially offer unique and beneficial selectivity for such analytes in GC separations. | en_US |
| dc.identifier.citation | Darko, E. (2019). A novel pH-adjusted water stationary phase for capillary gas chromatographic separations (Doctoral thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca. | en_US |
| dc.identifier.doi | http://dx.doi.org/10.11575/PRISM/36356 | |
| dc.identifier.uri | http://hdl.handle.net/1880/110161 | |
| dc.language.iso | eng | en_US |
| dc.publisher.faculty | Science | en_US |
| dc.publisher.institution | University of Calgary | en |
| dc.rights | University of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission. | en_US |
| dc.subject | Gas chromatography | en_US |
| dc.subject | Water stationary phase | en_US |
| dc.subject | Ionizable compounds | en_US |
| dc.subject.classification | Education--Sciences | en_US |
| dc.title | A Novel pH-adjusted Water Stationary Phase for Capillary Gas Chromatographic Separations | en_US |
| dc.type | doctoral thesis | en_US |
| thesis.degree.discipline | Chemistry | en_US |
| thesis.degree.grantor | University of Calgary | en_US |
| thesis.degree.name | Doctor of Philosophy (PhD) | en_US |
| ucalgary.item.requestcopy | true |