Used as a titrant in iodometric methods for the determination of sulfur dioxide in food, beverages, and environmental samples. Provides a stable and precise source of sulfite ions for calibration and standardization in analytical procedures. Commonly applied in quality control laboratories to ensure accurate measurement of SO₂ levels, especially in wine, dried fruits, and water samples where sulfur dioxide acts as a preservative. Its standardized concentration allows for reliable quantification through redox titration, ensuring compliance with regulatory limits.