Analytical Sciences

Abstract − Analytical Sciences, 15(1), 47 (1999).

Additive-Salt Effect on Low Detection Limit and Slope Sensitivity in Response of Potassium- and Sodium-Selective Neutral Carrier Based Electrodes and Their Liquid-Membrane Based Ion-Sensitive Field-Effect Transistor
Shin-ichi WAKIDA*1* , Takashi MASADOME*2 , Toshihiko IMATO*3 , Yasuhiko SHIBUTANI*4 , Kenji YAKABE*4 , Toshiyuki SHONO*4 and Yasukazu ASANO*5
*1 Department of Energy and the Environment, Osaka National Research Institute, Agency of Industrial Science and Technology, Ministry of International Trade and Industry, Midorigaoka, Ikeda, Osaka 563-8577, Japan
*2 Department of Chemical Science and Engineering, Ariake National College of Technology, Higashi-Hagio, Omuta, Fukuoka 836-8585, Japan
*3 Department of Chemical Science and Technology, Faculty of Engineering, Kyushu University, Hakozaki, Fukuoka 812-8581, Japan
*4 Department of Applied Chemistry, Osaka Institute of Technology, Asahi, Osaka 535-8585, Japan
*5 Laboratory of Chemistry, Department of General Education, Ariake National College of Technology, Omuta, Fukuoka 836-8585, Japan
The remarkable effect of additive salts on low detection limits as well as slope sensitivities were observed for the response characteristics of bis(crown) and valinomycin based poly(vinyl chloride) (PVC) membrane electrodes. The low detection limits and the slope sensitivities for bis(crown) and valinomycin based PVC membrane electrodes were improved apparently as the hydrophobicity of the additive salts increases. In order to clarify the effect of additive salts of the PVC membrane electrodes, the response characteristics of liquid-membrane based K + and Na + -ISEs, which were fab-ricated by using micro-ion-sensitive field-effect transistors (m-ISFETs), were evaluated. The low detection limits and the slope sensitivities in the responses of the neutral-carrier based K + and Na + -m-ISFETs also changed remarkably with the kind as well as the concentration of the additive salts. (Keywords: Additive salts, response behavior, ion-selective electrode, neutral carrier, liquid membrane, potassium and)