Analytical Performance of CE Microchips with Amperometric Detection

Abstract

Miniaturized Total Analysis Systems (µTAS), such as microchip electrophoresis devices are promising tools for analytical purposes. Capillary electrophoresis (CE) microchips made of various materials, e.g., poly(methylmethacrylate) (PMMA). Topas (thermoplastic olefin polymer of amorphous structure), and glass have been evaluated in this work. An electrochemical detection that combines adequately with these polymeric and glass microchips has been employed. The performance of amperometric detectors based on an end‐channel configuration was tested. Thus, integration and alignment of gold/platinum wire and thick‐film (screen‐printed carbon electrodes) working electrodes was studied. In order to verify the correct alignment of the end‐channel metal‐wire detector, a gold‐based dual electrode detector was also employed. The dual detector was based on a gold film within the separation channel and a gold wire at the end of the channel. The microchip pretreatment, which can affect the charge on the channel surface and electroosmotic flow (EOF), has been discussed, as well as the separation and injection performance.