Sulfite (free) Titrets Kit, Iodometric Method, Range: 10-100 ppm as SO3 (Recommended Alternative to Hach Part 148002)

Sulfite is not usually present in surface waters. If sulfite is discharged in effluents or from domestic wastewaters, it readily oxidizes to form sulfate. Sodium sulfite is the most common form of sulfite and is an excellent reducing agent with applications as an oxygen scavenger. Sulfite concentrations in boiler and process waters must be monitored routinely to avoid overtreatment. Waste treatment plants that use sulfur dioxide to remove excess chlorine must monitor their effluents for sulfite. Sulfites have been used for centuries to sanitize and preserve foods. They are used worldwide in the wine industry as antioxidant and antimicrobial agents. However, sulfites have been identified as causative agents in certain allergic reactions suffered by asthmatics. As a result, the FDA and the Bureau of Alcohol, Tobacco, and Firearms have mandated that sulfites in foods and beverages, at levels of 10 ppm or higher, be identified on the label. The Iodometric Method (Sulfite) References: ASTM D 1339-84, Sulfite Ion in Water, Test Method C. APHA Standard Methods, 22nd ed., Method 4500-SO3 2- B - 2000. USEPA Methods for Chemical Analysis of Water and Wastes, Method 377.1 (1983). CHEMetrics' sulfite test kits employ the iodometric chemistry in which sulfite is titrated with iodide-iodate titrant in an acid solution using a starch indicator. Thiosulfate will titrate as sulfite. Sulfamic acid is added to the sample to prevent interference from nitrite. Results are expressed as ppm (mg/L) SO₃.