| Ion chromatography (IC) is an analytical technique that is in a mature stage of its lifecycle for use in the separation and quantification of ions in commercial and industrial settings. Although current IC methods are robust for ion analysis, the current IC stationary phases fall short on system ruggedness and separation speed. Thus, new technologies and methods are being implemented to rejuvenate research in IC. This thesis investigates the preparation and use of carbon as a support for novel stationary phases for IC.;The first part of this thesis involves probing the retention characteristics of pure carbon phases and carbon-clad zirconia phases as stationary supports for IC. Ion exchange sites were introduced to the particles through the use of charged surfactants. It was observed that the phases could be converted from a reversed phase medium to an anion-exchange with the use of three different cationic surfactants. Purely, porous graphitic carbon columns coated with surfactant exhibited pressure increases and loss of resolution at higher column capacities. This is a significant improvement to pH extended ethylene-bridged silica columns that show complete failure in less than 8 h of use when conventional IC eluents were used. However, carbon-clad zirconia coated with surfactant showed stability after an initial loss of capacity.;As an alternative, charge sites can be covalently attached to carbon surfaces using diazonium chemistry. This methodology allows for a quicker startup time and no loss of capacity, providing long life columns. A procedure was developed that allows carbon-clad zirconia particles to be converted into strong and weak ion-exchange media by in situ diazonium generation and thermal deposition. The surface modification can be applied to planar carbon surfaces and on non-porous 2 mum and porous 3 mum carbon-based particles. Columns based on this method showed stable and reproducible retention for > 33,000 column volumes, which exceeds most commercial columns Finally, to add efficiency and provide another means of particle composition, latex particles were added to columns containing modified 2 mum particles, which also allows for the use of short column lengths.;IC separations are typically performed using hydroxide or carbonate/bicarbonate eluents to provide cheap, fast and sensitive separations of ions. However, silica stationary phases and many polymer phases cannot withstand the high alkalinity of such eluents. If polymers are able to withstand the high pH, they can deteriorate under pressure or produce lower efficiencies than alternate IC media. |
