title: Flow-injection potentiometric determination of triiodide by plasticized poly(vinyl chloride) membrane electrodes and its application to the determination of chlorine-containing disinfectants.
abstract: Plasticized poly(vinyl chloride) (PVC) membranes of different compositions were tested for use in the construction of potentiometric flow detectors for triiodide. A membrane with a 2:1 (w/w) 2-nitrophenyl octyl ether to PVC ratio was selected. The influence of thiosulphate in the carrier solution composition and of the flow-injection variables on the determination of triiodide was studied. In the selected conditions, a linear relationship between peak height and log[I(3)(-)] was obtained between 5 x 10(-6) and 1 x 10(-4)moll(-1) triiodide. Peak height relative standard deviations for 2 x 10(-5) and 1 x 10(-4)moll(-1) triiodide were +/-0.4 and +/-1.8%, respectively, and sampling frequency was 80 samples per hour. The method proposed was applied satisfactorily to the iodometric determination of different chlorine-containing disinfectants, among them trichloroisocyanuric acid and dichloroisocyanurate in several types of commercial sample.
authors.affiliation: Department of Analytical Chemistry, Faculty of Chemistry, University of Murcia, 30071-Murcia, Spain.
authors.forename: Joaquín A
authors.initials: JA
authors.lastname: Ortuño
authors.forename: Concepción
authors.initials: C
authors.lastname: Sánchez-Pedreño
authors.forename: Jorge
authors.initials: J
authors.lastname: Hernández
authors.forename: Domingo J
authors.initials: DJ
authors.lastname: Oliva