The use of a new styrene-divinylbenzene copolymer bead, Showdex Polymerpak D-814, as a stationary phase in high-performance liquid chromatography is investigated. Unlike conventional silica-based stationary phases, copolymer beads may be used with both aqueous and organic mobile phases. The effect of the mobile phase on solute retention with the copolymer beads is described. Although the copolymer beads exhibit characteristics of both solid and liquid stationary phases, it is shown that the beads act primarily as a liquid when used with the mobile phases chosen for this work. It is further shown that solute retention on the beads results from dispersion interactions between the solute and the stationary phase. Batch extraction distribution constants are determined to confirm the validity of the distribution model proposed. The chromatographic behavior of a variety of aromatic compounds is described. These range from polycyclic aromatic hydrocarbons to substituted benzenes to phthalate esters. A quantitative measure of the effect of a substituent group on retention is developed from an analysis of the experimental results. This measure is then used to successfully predict the retention behavior of some disubstituted benzene compounds. Some model separations are developed to illustrate the usefulness of this measure. Finally, the implications of this work for gradient elution chromatography are discussed.

A high speed stirring apparatus was constructed for following the kinetics of metal ion extraction by chelating agents. The semi-automated system is capable of measuring reactions with half lives of 20 seconds or more with data being collected every second. Experimental data obtained with the device are superior to those collected by batch shakers, fixed interface cells, falling drop, or other stirring devices. The use of a microporous Teflon membrane phase separator along with the thermodynamic relation, the Gibbs Equation, enabled the measurement of drop sizes in a two phase liquid-liquid dispersion. This allowed the determination of the quantity of interfacial area as a function of stir rate. The effect of interfacial area on the rate of extraction of five different chelating agents with various divalent metal ions was determined in this study. The role of the interfacial area in extraction kinetics was found in a system where diffusional effects are negligible. This information provides an answer to the question of whether the rate determining step of extraction occurs in either the bulk aqueous phase or in the interfacial region. The proportionality between rate and specific interfacial area was employed to find the magnitude of the contributions of the bulk and interfacial components and also allowed the calculation of the individual rate constants. Evaluation of the bulk and interfacial rate constants yields important fundamental information as to the chemical nature and differences between the chloroform/water interface and the bulk aqueous phase. The results appear to illustrate that the interface is a more conducive medium for reaction between metal and ligand than the aqueous phase. The role of foreign species, namely nonionic surfactants, on the rate of extraction was investigated to explore their applicability in solvent extraction. Nonionic surfactants were found to enhance the rates of extraction to different extents in different metal systems.

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