1. Methods of test for sodium tripolyphosphate (pentasodium triphosphate) and sodium pyrophosphate (tetrasodium pyrophosphate) for industrial use. Determination of orthophosphate content Part 8, (7th June 1974) Authors: British Standards Institution, Record Type: Book Extent: 1 online resource (10 pages) View Content: Available online (eLD content is only available in our Reading Rooms) ↗