microtest® Test Kit Specifications

microtest Nitrate NED

Colorimetric Test for


0 – 20 mg/L NO3-

Product Code654000
ContentsReagent A, 15 mL
Reagent B, 2.5 g
Measuring spoon
Cuvette, 4 mL
Colour chart
Instructions for Use
Analytical MethodReduction to nitrite, diazotation / azocoupling: In acid conditions, nitrate is reduced to nitrite by metallic zinc. Then nitrite forms a diazo-compound with sulfanilamide. This diazo-compound reacts with N-(1-naphthyl)-ethylenediamine forming an intensely coloured pink azo dye, the intensity of which is related to the nitrite concentration.
Number of Tests80
InterferencesWater constituents at concentrations commonly found in natural waters will not cause interferences. Oxidants like chlorine and ozone will interfere, causing low results. Nitrite will interfere seriously (same reaction). Seawater: Seawater and waters high in salinity will cause low results. In order to compensate for that, multiply reading by 1.5.
Measuring RangeThe standard measuring range is 0 – 20 mg/L. The colour comparator has 6 colour fields: 0–1–2–5–10–20 mg/L. For higher nitrate concentrations, the sample has to be diluted. A 1:4 sample dilution can be carried out easily, thus extending the measuring range to 80 mg/L.
Shelf Life2 years
ApplicationsDetermination and monitoring of nitrate levels in natural waters (environmental monitoring), waste water.