title: Potassium ion-selective membrane electrodes based on 1,3-alternate calix[4]crown-5-azacrown-5.
abstract: A series of 1,3-alternate calix[4]azacrown ethers for which the monoaza and unsymmetrical crowned-azacrown with different side arms were examined as an ionophore for ion-selective polymeric membrane electrode toward potassium ion. Among them, the electrode based on calix[4]crown-5-azacrown-5 with a phenyl group exhibited near Nernstian response for K(+) ions over a wide concentration range (1x10(-5) to 1x10(-1) M) with a limit of detection of 2x10(-6) M. It has a fast response time of approximately 2-3 s and can be used for at least 2 months without observing any major deterioration. Selectivity coefficients indicated that interference from all common alkali, alkaline and transition metal ions was very small.
authors.affiliation: School of Chemistry and Molecular Engineering, Center for Molecular Catalysis, Seoul National University, Seoul 151-742, South Korea.
authors.forename: Sungeun
authors.initials: S
authors.lastname: Kim
authors.forename: Hasuck
authors.initials: H
authors.lastname: Kim
authors.forename: Kwan Ho
authors.initials: KH
authors.lastname: Noh
authors.forename: Seoung Ho
authors.initials: SH
authors.lastname: Lee
authors.forename: Sung Kuk
authors.initials: SK
authors.lastname: Kim
authors.forename: Jong Seung
authors.initials: JS
authors.lastname: Kim