Ceramic capillary electrophoresis chip for the measurement of inorganic ions in water samples

Abstract

We present a microchip capillary electrophoresis (CE) device build-up in low temperature co-fired ceramics (LTCC) multilayer technology for the analysis of major inorganic ions in water samples in less than 80 s. Contactless conductivity measurement is employed as a robust alternative to direct-contact conductivity detection schemes. The measurement electrodes are placed in a planar way at the top side of the CE chip and are realized by screen printing. Laser-cutting of channel and double-T injector structures is used to minimize irregularities and wall defects, elevating plate numbers per meter up to values of 110,000. Lowest limit of detection is 6 μM. The cost efficient LTCC module is attractive particularly for portable instruments in environmental applications because of its chemical inertness, hermeticity and easy three-dimensional integration capabilities of fluidic, electrical and mechanical components.