title: Ultra-high-sensitive extraction-photometric determination of sodium ion using flow injection analysis with a chromogenic calix[4]arene derivative and a laser interferometric photothermal detector.
abstract: A novel flow injection analysis (FIA) system for ultra-high-sensitive determination of Na(+), which involves laser interferometric photothermal equipment as the detector, was designed using a proton-dissociable chromogenic calix[4]arene derivative with a dinitrophenol moiety as the extraction-photometric reagent. The chromogenic calix[4]arene derivative showed an excellent extractability toward Na(+), which reflected the cation-complexing property of the tetraethyl ester derivative of calix[4]arene. As the calibration graph of the Na(+) concentration could be successfully obtained at the nanomolar level by this method, the proposed FIA system was found to be promising for highly sensitive determination of Na(+) in very dilute samples such as supply water and cooling water in power plants.
authors.affiliation: Department of Applied Chemistry, Faculty of Systems Engineering, Wakayama University, Wakayama, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Tsuda
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Nakahara
authors.forename: Koji
authors.initials: K
authors.lastname: Machitani
authors.forename: Masato
authors.initials: M
authors.lastname: Kannaka
authors.forename: Eiji
authors.initials: E
authors.lastname: Takahashi
authors.forename: Keiichi
authors.initials: K
authors.lastname: Kimura