EPA Colorimetric Testing for Nitrate + Nitrite

Collaborative Efforts to Improve Environmental Monitoring
Oral Presentation

Prepared by S. McFaul
SEAL Analytical, 6501 W Donges Bay Rd, Mequon, Wisconsin, 53092, United States

Contact Information: [email protected]; 231-631-7274


There are currently several different methods options available that are USEPA approved for testing Nitrate + Nitrite. Method stability, applicable sample types, reagent preparation and storage, reaction interferences should all be considered when a laboratory is deciding which test to perform. The four approved colorimetric methods for Nitrate + Nitrite testing are by Cadmium Reduction, Hydrazine Reduction, Enzymatic Reduction, and Vanadium Chloride Reduction (“Easy 1-Reagent”). These four methods will be discussed and positives and negatives will be addressed, as well as other considerations associated with these methods.