Used in environmental and water quality testing to calibrate instruments for measuring nitrite levels in drinking water, wastewater, and natural water sources. Essential in agricultural labs to monitor soil nitrite content, helping assess soil fertility and optimize fertilizer use. Commonly used in food and beverage industries to control nitrite concentrations in cured meats and preserved products, ensuring compliance with safety regulations. Also employed in research laboratories for analytical procedures such as spectrophotometry and ion chromatography, where accurate concentration standards are required for reliable results.