Used in environmental and industrial laboratories to measure sulfur dioxide levels in air and water samples. Commonly applied in water quality testing to determine residual sulfite in wastewater or drinking water. Employed in the food and beverage industry to monitor sulfite content in products like wine, where sulfites act as preservatives. Also utilized in calibration of analytical instruments such as ion chromatographs and spectrophotometers for accurate quantification of sulfite ions. Ensures compliance with regulatory standards for sulfur content in various matrices.