Thin layer coulometric determination of nitrate in fresh waters

Manzar Sohail; Roland De Marco; Krystina Lamb; Eric Bakker

doi:10.1016/j.aca.2012.07.026

Thin layer coulometric determination of nitrate in fresh waters

Anal Chim Acta. 2012 Sep 26:744:39-44. doi: 10.1016/j.aca.2012.07.026. Epub 2012 Jul 27.

Authors

Manzar Sohail¹, Roland De Marco, Krystina Lamb, Eric Bakker

Affiliation

¹ Faculty of Science, Health, Education and Engineering, University of the Sunshine Coast, Maroochydore DC, Queensland 4558, Australia.

PMID: 22935372
DOI: 10.1016/j.aca.2012.07.026

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.