Analytical Sciences


Abstract − Analytical Sciences, 25(12), 1397 (2009).

Development of a Micro-Potentiometric Sensor for the Microchip Analysis of Alkali Ions
Adelina SMIRNOVA,* Kazuma MAWATARI,* Hiroko TAKAHASHI,* Yo TANAKA,** Hiroaki NAKANISHI,*** and Takehiko KITAMORI**
*Microchemistry Group, Kanagawa Academy of Science and Technology, 3-2-1 Sakado, Takatsu, Kawasaki 213-0012, Japan
**Department of Applied Chemistry, Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-8656, Japan
***Shimadzu Corp., 3-9-4 Hikaridai, Seika, Fusoraku, Kyoto 619-0237, Japan
This paper reports on the development of a micro-potentiometric sensor based on external microelectrodes introduced into a microchip. We miniaturized reference and ion-selective electrodes (ISEs) and embedded them into a plastic (PDMS) microchip; the miniaturization of ISE was attained by using a monolithic capillary-based membrane. This sensor was applied to the detection of alkali ions (Na+, K+ and NH4+) in a microflow on the μg/L level.