SINGLE-STEP ANALYSIS BY CAPILLARY ELECTROPHORESIS Single-step Analysis of Metabolites by Capillary Electrophoresis using On-line Sample Preconcentration with Chemical Derivatization By

New strategies for integrating sample pretreatment with chemical analyses under a single format is required for rapid, sensitive and enantioselective analyses of low abundance metabolites in complex biological samples. Capillary electrophoresis (CE) offers a unique environment for controlling analyte/reagent band dispersion and electromigration properties using a discontinuous electrolyte system allowing for highly efficient separations to be achieved. A fundamental study of the thermodynamic and electrokinetic parameters influencing enantioselectivity in chiral CE separation is first examined. A new strategy for single-step analysis of low abundance metabolites via on-line sample preconcentration with chemical derivatization by CE (SPCD-CE) is then detailed within. In-capillary sample preconcentration serves to enhance concentration sensitivity via electrokinetic focusing of long sample injection volumes for lower detection limits, whereas chemical derivatization by zone passing of single or multiple reagents is used to expand detectability and selectivity, notably for enantiomeric resolution of metabolites lacking intrinsic chromophores. Together, on-line SPCD-C