title: Thin layer coulometric determination of nitrate in fresh waters.
abstract: A nitrate ion-selective electrode (ISE) employing a permeable tubular membrane impregnated with a conventional ISE cocktail has been used successfully in the coulometric analysis of nitrate in fresh waters. The liquid ISE membrane comprising a nitrate ionophore [tridodecylmethylammonium nitrate (TDMAN)], lipophilic electrolyte [tetradodecyl-ammoniumtetrakis(4-chlorophenyl)borate (ETH 500)] and plasticizer [bis(3-ethyl-hexyl)sebacate (DOS)] was supported on a porous polypropylene tube. Coulometric analysis with the tubular membrane ISE showed that nitrate could be detected in the range 10-100 μM with a precision of 2.3% relative standard deviation (RSD), limit of detection of 1.1 μM and relative accuracy of 4.4% compared to a certified reference material (CRM) Lake sample.
authors.affiliation: Faculty of Science, Health, Education and Engineering, University of the Sunshine Coast, Maroochydore DC, Queensland 4558, Australia.
authors.forename: Manzar
authors.initials: M
authors.lastname: Sohail
authors.forename: Roland
authors.initials: R
authors.lastname: De Marco
authors.forename: Krystina
authors.initials: K
authors.lastname: Lamb
authors.forename: Eric
authors.initials: E
authors.lastname: Bakker