title: A highly selective polymeric membrane barium(II) electrode based on a macrocyclic tetrabasic ligand as neutral carrier.
abstract: A novel barium(II) ion-selective polymeric membrane electrode based on a macrocyclic tetrabasic ligand that derived from the reaction of 4,6-diacetylresorcinol and ethylenediamine in the molar ratio 1:1 as neutral carrier was described. The electrode, with optimum membrane composition, exhibited an excellent near-Nernstian response for Ba(2+) ion ranging from 3.6 x 10(-6) to 1.0 x 10(-1) mol/L with a detection limit of 1.9 x 10(-6) mol/L and a slope of 29.7 +/- 0.2 mV/dec in pH 4.0 nitrate buffer solution at 25 degrees C. It had a relatively fast response time (10 s), good selectivity towards Ba(2+) ion, and could be used over a wide pH range of 2.5-7.5. Then, the response mechanism was discussed in view of UV-visible spectroscopy and the A.C. impedance technique. Finally, the proposed electrode was successfully applied to the detection of Ba(2+) ions in real samples as well as in sulfate(II) ions in water.
authors.affiliation: Key Laboratory on Luminescence and Real-Time Analysis, Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, Chongqing, 400715, China.
authors.forename: Yu-Hua
authors.initials: YH
authors.lastname: Ma
authors.forename: Ruo
authors.initials: R
authors.lastname: Yuan
authors.forename: Ya-Qin
authors.initials: YQ
authors.lastname: Chai
authors.forename: Xin-Lu
authors.initials: XL
authors.lastname: Liu