Used as a reference standard in environmental testing laboratories to calibrate instruments and validate analytical methods for the determination of nitrite nitrogen in water samples. Ensures accuracy and reliability in monitoring nitrite levels in drinking water, wastewater, and surface water, helping to comply with regulatory requirements and protect public health. Commonly used in spectrophotometric, colorimetric, and ion chromatography analyses. Supports quality control procedures in routine water quality testing and research studies related to nutrient pollution and aquatic ecosystem health.