Poly(methylmethacrylate) and Topas capillary electrophoresis microchip performance with electrochemical detection

A capillary electrophoresis (CE) microchip made of a new and promising polymeric material: Topas (thermoplastic olefin polymer of amorphous structure), a cyclic olefin copolymer with high chemical resistance, has been tested for the first time with analytical purposes, employing an electrochemical detection. A simple end‐channel platinum amperometric detector has been designed, checked, and optimized in a poly‐(methylmethacrylate) (PMMA) CE microchip. The end‐channel design is based on a platinum wire manually aligned at the exit of the separation channel. This is a simple and durable detection in which the working electrode is not pretreated. H 2 O 2 was employed as model analyte to study the performance of the PMMA microchip and the detector. Factors influencing migration and detection processes were examined and optimized. Separation of H 2 O 2 and L ‐ascorbic acid (AsA) was developed in order to evaluate the efficiency of microchips using different buffer systems. This detection has been checked for the first time with a microchip made of Topas, obtaining a good linear relationship for mixtures of H 2 O 2 and AsA in different buffers.