New detector tube for the detection of nitrite in water
Vladimír Pitschmann *, Zbyněk Kobliha a, Ivana Tušarová, David Vetchý b
Oritest spol. s r.o., Staropramenná 17, 15000 Praha, Czech Republic
a NBC Defence Institute (Vyškov), University of Defence, Kounicova 65, 66200 Brno, Czech Republic
b Faculty of Pharmacy, Veterinary and Pharmaceutical University Brno, Palackého 1-3, 61200 Brno, Czech Republic
E-mail: * pitschmann@oritest.cz
Abstract: A new colorimetric detector tube for the detection of trace concentrations of nitrite in water was developed. The detector tube is based on a diazo coupling reaction of nitrite with dapsone and N-(1-naphthyl) ethylenediamine dihydrochloride during the formation of red-violet azo dye. Spherical granules (pellets) made from the composite material were used as the carrier of chemical reagents. They were prepared by pelletizing the mixture of microcrystalline cellulose, lactose, kaolin and polyvinylpyrrolidone. Colouring is done on a layer of silica gel impregnated with citric acid. The detector tube is highly sensitive, selective and stable when stored. The detection limit is 0.1 mg.ml–1, i.e. 0.03 mg.ml–1 N(NO2–). The optimal measuring range of nitrite concentration in the analyzed sample ranges from 0.5 to 80 mg.ml–1, i.e. 0.15—24.36 mg.ml–1 N(NO2–). The detector tube can easily be structurally modified for analysis of nitrates with a detection limit of 1 mg/mL, i.e. 0.23 mg.ml–1 N(NO3–).
Keywords: detector tube, composite carrier, dapsone, N-(1-naphthyl) ethylenediamine dihydrochloride
Full paper in Portable Document Format: acs_0151.pdf
Acta Chimica Slovaca, Vol. 6, No. 1, 2013, pp. 100—105, DOI: 10.2478/acs-2013-0016