|Range||MDL||Method||Kit Catalog No.||Refill Catalog No.|
|0-3.4 ppm as N||0.3 ppm||Zinc Reduction||K-6905||R-6905|
|0-4.5 ppm as N||0.4 ppm||Cadmium Reduction||K-6904||R-6902|
|0-45 ppm as N||4 ppm||Cadmium Reduction||K-6909D||R-6904|
|0-225 ppm as N||20 ppm||Cadmium Reduction||K-6909A||R-6904|
|0-675 ppm as N||60 ppm||Cadmium Reduction||K-6909B||R-6909|
|0-2700 ppm as N||240 ppm||Cadmium Reduction||K-6909C||R-6909|
|Range||Method||Kit Catalog No.|
|0-1.50 ppm as N||Zinc Reduction||K-6913|
|0-1.50 ppm as N||Cadmium Reduction||K-6903|
|0-7.50 ppm as N||Cadmium Reduction||K-6923|
|0-50.0 ppm as NO₃||Cadmium Reduction||K-6933|
Nitrate is the most completely oxidized form of nitrogen. It is formed during the final stages of biological decomposition, either in wastewater treatment facilities or in natural water supplies. Low-level nitrate concentrations may be present in natural waters. However, a Maximum Contaminant Level of 10 ppm nitrate-nitrogen has been established for drinking water by the USEPA.
Nitrate is reduced to nitrite using cadmium as the reducing agent. The resulting nitrite concentration is then determined colorimetrically. This method is applicable to drinking and surface waters, as well as domestic and industrial wastes. Nitrite will interfere with this test. Results are expressed as ppm (mg/L) NO3-N or NO3.
Nitrate is reduced to nitrite using zinc as the reducing agent. The resulting nitrite concentration is then determined colorimetrically. This method is applicable to industrial wastewaters, drinking, and surface waters. These test kits can also be used for the analysis of seawater. This method will measure nitrate in the presence of low levels of nitrite (by difference). Results are expressed as ppm (mg/L) NO3-N.