التفاصيل البيبلوغرافية
| العنوان: |
Microchip capillary electrophoresis: improvements using detection geometry, on-line preconcentration and surface modification |
| المؤلفون: |
Guan, Qian, author, Henry, Charles S., advisor, Strauss, Steven H., committee member, Van Orden, Alan K., committee member, Krummel, Amber, committee member, Hanneman, William H., committee member |
| بيانات النشر: |
Colorado State University. Libraries |
| سنة النشر: |
2007 |
| المجموعة: |
Digital Collections of Colorado (Colorado State University) |
| مصطلحات موضوعية: |
surface modification with mixed surfactants, microchip capillary electrophoresis, on-line sample preconcentration using field amplified stacking techniques, detection geometry modification with bubble cell, electrochemical detection |
| الوصف: |
2012 Summer. ; Includes bibliographical references. ; Capillary electrophoresis and related microfluidic technologies have been utilized with great success for a variety of bioanalytical applications. Microchip capillary electrophoresis (MCE) has the advantages of decreased analysis time, integrated sample processing, high portability, high throughput, minimal reagent consumption, and low analysis cost. This thesis will focus on the optimization of our previous microchip capillary electrophoresis coupled electrochemical detection (MCE-ECD) design for improved separation and detection performance using detection geometry, on-line preconcentration and surface modification. The first effort to improve detection sensitivity and limits of detection (LODs) of our previous MCE-ECD system is established by an implementation of a capillary expansion (bubble cell) at the detection zone. Bubble cell widths were varied from 1× to 10× the separation channel width (50 μm) to investigate the effects of electrode surface area on detection sensitivity, LOD, and separation efficiency. Improved detection sensitivity and decreased LODs were obtained with increased bubble cell width, and LODs of dopamine and catechol detected in a 5× bubble cell were 25 nM and 50 nM respectively. In addition, fluorescent imaging results demonstrate ~8% to ~12% loss in separation efficiency in 4× and 5× bubble cell, respectively. Another effort for enhancing detection sensitivity and reducing LODs involves using field amplified sample injection and field amplified sample stacking. Stacking effects were shown for both methods using DC amperometric and pulsed amperometric detections. Decreased LODs of dopamine were achieved using both on-line sample preconcentration methods. The use of mixed surfactants to affect electroosmotic flow (EOF) and alter separation selectivity for electrophoretic separations in poly(dimethylsiloxane) (PDMS) is also presented in this thesis. First the effect of surfactant concentration on EOF was studied using the current ... |
| نوع الوثيقة: |
text |
| وصف الملف: |
born digital; doctoral dissertations; application/pdf |
| اللغة: |
English |
| العلاقة: |
Guan_colostate_0053A_11138.pdf; ETDF2012400292CHEM; http://hdl.handle.net/10217/67921Test |
| الإتاحة: |
http://hdl.handle.net/10217/67921Test |
| حقوق: |
Copyright and other restrictions may apply. User is responsible for compliance with all applicable laws. For information about copyright law, please see https://libguides.colostate.edu/copyrightTest. |
| رقم الانضمام: |
edsbas.33EFEA10 |
| قاعدة البيانات: |
BASE |
