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Mixed-mode silica monolith as an efficient separation medium for capillary electrochromatography

Jemale, Alia Sofie (2010) Mixed-mode silica monolith as an efficient separation medium for capillary electrochromatography. Masters thesis, Universiti Teknologi Malaysia, Faculty of Science.



Silica monolith column having mixed-mode i.e., hydrophobic (C18) and anion exchange interaction was successfully synthesized by on-column modification of the hybrid tetramethoxysilanes (TMOS) and methyltrimethoxysilanes (MTMS) using octadecyldimethyl-(N-N-diethylamino)silane (ODS) and ion exchange monomer of N-[3-(dimethylamino)propyl]acrylamide (DMAPAA-Q) methyl chloride-quaternary salt, for the surface modification. The preparation of the ODS/DMAPAA-Q silica monolith column was carried out in a fused silica capillary column of 75 µm internal diameter. At each modification stage, the ODS/DMAPAA-Q silica monolith column was chromatographically characterized with micro liquid chromatography (µLC) and produced separation efficiencies of up to 43000 plates/min at the optimum velocity using the test mixture of alkylbenzenes, and 41800 plates/min for selected nucleotides. The ODS/DMAPAA-Q silica monolith column was also characterized physically with scanning electron microscope (SEM), and showed to have an average through-pore size and skeleton size of 2.2 µm and 2.0 µm, respectively. The ODS/DMAPAA-Q silica monolith column was then characterized in capillary electrochromatography (CEC) for the separation of inorganic and organic ions using a 50 mM phosphate pH 6.9 background electrolyte. The inorganic anions and organic ions were separated within 10 mins with column efficiency up to 114900 plates/min. The results suggest that modifying a silica monolith capillary column through in-situ polymerization of a monomer carrying a functional group can yield high efficiency columns for the ion-exchange-mode separation as well as for reversed-phased separations. The analysis of the porous silica monolith columns with CEC yields higher performance than CZE analysis for the separation of anions.

Item Type:Thesis (Masters)
Additional Information:Thesis (Sarjana Sains (Kimia)) - Universiti Teknologi Malaysia, 2010; Supervisor : Assoc. Prof. Dr. Jafariah Jaafar
Uncontrolled Keywords:drugs, analysis, statistics, data processing
Subjects:T Technology > T Technology (General)
T Technology > TP Chemical technology
ID Code:12364
Deposited On:25 May 2011 07:55
Last Modified:17 Sep 2017 08:17

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