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64 Name: SODIUM TRIPOLYPHOSPHATE CAS No.: 7758-29-4 Chemical Formula: Na5P3°lo Formula Weight: 368 I Description . White, odorless granules or powder. Use: NAS/CWTC 035/82 Na5P3O1o 6HgO 476 Used as corrosion inhibitor, sequestrant, and water softener. Purity Requirements: The analyses are to be performed on the sodium tripoly- phosphate show the presence of cadmium and lead but at levels far below that which would necessitate RMIC values based on a maximum dosage of 12.9 mg/liter. If analyses are desired, the following protocol is recomended. Bulk Sample Collection: Sample in accordance with Standard for Sodium Tripoly- phosphate, AWWA B503-78, American Water Works Associa- tion, Denver, Colorado (1978). Analytical Sample Preparation: Weigh out 2.5 g of sodium tripolyphosphate. In a 150-ml acid-washed beaker, dissolve the sample in 100 ml of deionized distilled water. Under a hood, acidify the solution with concentrated HNC3 to a pH of less than
65 2. Gently heat the solution to reduce the volume below 100 ml, making certain that it does not boil. Quan~ita- tively transfer to a 100-ml acid-washed volumetric flask and make to volume with deionized distilled water. Process a reagent blank by the same procedure. Sample Analyses: The analyses are to be performed on the sodium tripoly- phosphate solution in accordance with: Standard Methods for the Examination of Water and Waste- water, 15th Edition, American Public Health Association, Washington, D.C. (1981). Cadmium Lead Section 304 Section 304