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| Author(s): |
Valeska Soares Aguiar
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | Campinas, SP. |
| Institution: | Universidade Estadual de Campinas (UNICAMP). Instituto de Química |
| Defense date: | 2011-12-15 |
| Examining board members: |
Carla Beatriz Grespan Bottoli;
Dosil Pereira de Jesus;
Mariana Franco Maggi Tavares
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| Advisor: | Carla Beatriz Grespan Bottoli |
| Abstract | |
Capillary Electrochromatography (CEC) is a separation technique that matches the chromatographic selectivity of High Performance Liquid Chromatography (HPLC) with the high efficiency of Capillary Electrophoresis (CE). The capillary column used in the separation is filled with a stationary phase, which can be particulate or monolithic. In this work, organic polymeric monoliths were prepared through in situ polymerization from the monomers octadecyl methacrylate (precursor and hydrophobic selector), ethylene dimethacrylate (cross-linking agent) and 2-acryloylamido-2-methylpropanesulfonic acid (ionizable component), using different types of porogenic solvents, such as isoamyl alcohol, amyl alcohol, cyclohexanol and 1,4-butanediol, in the presence or absence of water. In the first step, the nature and proportion between the porogenic solvents were varied and, in the second, the same occurred with the proportion between the set of monomers and porogenic solvents. The stationary phases were characterized by physical techniques such as scanning electron microscopy and porosimetry; and the columns prepared with the monolithic material were evaluated through the CEC technique. The columns presented efficiencies in the range of 3000 to 50000 plates m. Analysis of the nitrogen adsorption and desorption isotherms and the pore distribution curves enable affirming that the synthesized monolithic material is essentially micro- and mesoporous. The macropores for the flow of the mobile phase were clearly observed in images of scanning electron microscopy. So, the monolithic phases have three types of pores: micro-, meso- and macropores. In the second part of this work, the repeatability of synthesis of the monolithic phases was evaluated and a lack of repeatability related to separation efficiency was noted. The monolithic phases had high apolar character and adequate methylenic selectivity for separation of apolar and aromatic analytes, such as alkylbenzenes, alkylparabens and polycyclic aromatic hydrocarbons (AU) | |
| FAPESP's process: | 09/10620-0 - Development and Caracterization of polimeric monolithic stationary phases for using in Capillary Electrochromatography |
| Grantee: | Valeska Soares Aguiar |
| Support Opportunities: | Scholarships in Brazil - Master |