Voltammetric assessment of new ionic liquids for their applications in capillary electrophoresis

Abstract: Purpose of the proposed research is to investigate the fundamental aspects of ion transfer across a polarized interface between water and the newly synthesized ionic liquids (ILs), in relation to applications of ILs in capillary electrophoresis (CE). Ion transfer voltammetry will be used to evaluate the parameters characterizing the interaction between a target ion and the counter-ion of IL, which will be correlated with those characterizing the separation of target ions in the IL coated CE capillary. Target ions will include organic poly-anions (polypeptides, mono- and polycarboxylates, polysulfates), which are likely to interact strongly with the IL cation. ILs composed of tetraalkylammonium (phosphonium) cation and a hydrophilic anion will be used as the background electrolyte in CE, so as to accomplish a modification of the inner surface of the CE capillary by the cation adsorption. Alternatively, the CE capillary will be modified by the covalently bonded IL cation. Expected results include the clarification of the role of IL in the CE separations, and new analytical procedures.