title: Determination of nitrites in water by in-electrode coulometric titration in reticulated vitreous carbon electrode.
abstract: Nitrite in water samples was determined by in-electrode coulometric titration in a reticulated vitreous carbon (RVC) electrode of 100 ppi porosity. The sample was mixed with dilute sulphuric acid and sodium sulphate, filled into a flow cell with the porous electrode and nitrite was oxidised to nitrate by constant current of 5 µA at which the potential of the electrode was monitored. The limits of detection and quantification were found to be 0.4 and 1.2 µg/L, respectively. The repeatability and reproducibility were 2.2 % and 2.6 %, respectively. The bias at 100 µg/L were found to be 0.3 %. The duration of the measurement is 2-3 min depending on the nitrite concentration. There were few interferences only, neutral and cationic surfactants decreased and increased slightly the signal, respectively. Humic acids above 30 mg/L increased the signal by 10 %. Drinking and surface water samples were analysed and the results matched well those from the photometric method.
authors.forename: Katarina
authors.initials: K
authors.lastname: Lenghartova
authors.forename: Lukas
authors.initials: L
authors.lastname: Lauko
authors.forename: Frantisek
authors.initials: F
authors.lastname: Cachob
authors.forename: Ernest
authors.initials: E
authors.lastname: Beinrohr