Used in environmental and water quality testing to calibrate instruments for measuring nitrite levels in drinking water, wastewater, and natural water bodies. Essential in agricultural labs to assess soil nitrite content, supporting fertilizer management. Employed in food and beverage industries to monitor nitrite concentrations in cured meats and processed foods, ensuring compliance with safety regulations. Commonly used in research and educational settings for analytical methods development and student training in ion chromatography and spectrophotometry.