Capillary zone electrophoresis with electrochemical detection — a simple and effective method to analyze oxygen-consuming and peroxide-forming processes

Numerous biological, chemical and photochemical processes consume molecular oxygen, thereby forming peroxides, hydroperoxides and even hydrogen peroxide. This paper describes a new system for monitoring quasi simultaneously oxygen uptake and peroxide formation. For this purpose capillary electrophoresis with electrochemical detection was connected to a new automated injector that periodically injects a sample of the reaction mixture into the capillary electrophoresis system without any contact with the atmosphere. The device was tested with some pharmacologically relevant reactions such as enzymatic oxidation of glucose catalyzed by glucose oxidase, enzymatic lipid oxidation by lipoxygenase and the photodynamic reaction of the anti-inflammatory drug ketoprofen.