PEROXYOXALATE CHEMILUMINESCENCE DETECTION IN CAPILLARY ELECTROPHORESIS

The feasibility of employing peroxyoxalate chemiluminescence (PO-CL) detection in capillary electrophoresis (CE) was demonstrated using a two-step approach for the CE separation and dynamic elution (elution under pressure) of the analytes. In this approach, potential problems associated with incompatibilities between mixed aqueous-organic solvent and electrically driven separation systems were avoided by switching off the CE power supply at an appropriate time and connecting the CE capillary to a syringe pump to effect dynamic elution. The effects of dynamic flow-rate and PO-CL reagent concentration on the CL signal intensity and/or peak width were examined for the measurements of three dansylated amino acids. The average limit of detection for these analytes using this PO-CL method is about 1.2 fmol (ca. 85 nM) which is approximately 35-fold lower than UV absorption methods.