This is an old revision of this page, as edited by Smokefoot (talk | contribs) at 17:57, 4 January 2014 (mention others). The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.
Revision as of 17:57, 4 January 2014 by Smokefoot (talk | contribs) (mention others)(diff) ← Previous revision | Latest revision (diff) | Newer revision → (diff)
Sodium phosphate is a generic term for a variety of salts of Na and phosphate (PO4), hydrogen phosphate (HPO4), and dihydrogenphosphate (H2PO4). Known compounds are shown in the table. Usually the hydrated salts are more common than the anhydrous forms.
| name | formula |
|---|---|
| monosodium phosphate (anhydrous) | NaH2PO4 |
| monosodium phosphate (monohydrate) | NaH2PO4(H2O) |
| monosodium phosphate (dihydrate) | NaH2PO4(H2O)2 |
| monosodium phosphate (anhydrous) | HNa2PO4 |
| disodium phosphate (dihydrate) | HNa2PO4(H2O)2 |
| disodium phosphate (heptahydrate) | HNa2PO4(H2O)7 |
| disodium phosphate (octahydrate) | HNa2PO4(H2O)8 |
| disodium phosphate (dodecahydrate) | HNa2PO4(H2O)12 |
| trisodium phosphate (anhydrous, hexagonal) | Na3PO4 |
| trisodium phosphate (anhydrous, cubic) | Na3PO4 |
| trisodium phosphate (hemihydrate) | Na3PO4(H2O)0.5 |
| trisodium phosphate (hexahydrate) | Na3PO4(H2O)6 |
| trisodium phosphate (octahydrate) | Na3PO4(H2O)8 |
| trisodium phosphate (dodecahydrate) | Na3PO4(H2O)12 |
In addition to these phosphates, sodium forms a number of useful salts with pyrophosphates (called diphosphates):
| name | formula |
|---|---|
| monosodium diphosphate (anhydrous) | NaH3P2O7 |
| disodium diphosphate (anhydrous) | Na2H2P2O7 |
| disodium diphosphate (hexahydrate) | Na2H2P2O7(H2O)6 |
| trisodium diphosphate (anhydrous) | Na3HP2O7 |
| trisodium diphosphate (hydrate) | Na3HP2O7(H2O) |
| trisodium diphosphate nonahydrate | Na3HP2O7(H2O)9 |
| tetrasodium phosphate (anhydrous) | Na4P2O7 |
| tetrasodium diphosphate (decahydrate) | Na4P2O7(H2O)10 |
Beyond the mono and diphosphates, sodium forms triphosphates, e.g. sodium triphosphate. Polymeric sodium phosphates are also well known, these include [[Kurrol’s salt, Graham’s salt, and Maddrell’s salt. Cyclic phosphates are called metaphosphates, they include the trimer and the tetramer Na3P3O9 and Na4P4O12.
Applications
Sodium phosphates have many applications in the food industry and for water treatment. For example, sodium phosphates are often used as leavening agents for baked goods. They are used to control pH of processed foods.
Safety
Sodium phosphates are popular in commerce in part because they are inexpensive and nontoxic.
Oral sodium phosphates for bowel preparation for colonoscopy may in some individuals carry a risk of kidney injury under the form of phosphate nephropathy. There are several oral phosphate formulations which are prepared extemporaneously. Oral phosphate prep drugs have been withdrawn in the United States, although evidence of causality is equivocal. Since safe and effective replacements for phosphate purgatives are available, several medical authorities have recommended general disuse of oral phosphates.
References
- ^ Klaus Schrödter, Gerhard Bettermann, Thomas Staffel, Friedrich Wahl, Thomas Klein, Thomas Hofmann "Phosphoric Acid and Phosphates" in Ullmann’s Encyclopedia of Industrial Chemistry 2008, Wiley-VCH, Weinheim. doi:10.1002/14356007.a19_465.pub3
- Lucina E. Lampila "Applications and functions of food-grade phosphates" Ann. N.Y. Acad. Sci. 2013, vol. 1301, pp. 37–44. doi:10.1111/nyas.12230
-
Markowitz, GS; Perazella, MA (Aug 12), "Acute Phosphate Nephropathy", Kidney Int., vol. 76, no. 10, pp. 1027–34, doi:10.1038/ki.2009.308, PMID 19675530
{{citation}}: Check date values in:|date=and|year=/|date=mismatch (help) -
Mackey, AC; Green, L; Amand, KS; Avigan, M (2009), "Sodium phosphate tablets and acute Phosphate Nephropathy", Am J Gastroenterol, vol. 104, no. 8 (published Aug), pp. 1903–6, doi:10.1038/ajg.2009.342, PMID 19661931
{{citation}}: Check date values in:|publication-date=(help)
External links
- Bell, Russel N (1973), "SODIUM ALUMINUM PHOSPHATE CHEESE EMULSIFYING AGENT", US Patent 3726960 (published April)
{{citation}}: Check date values in:|publication-date=(help) - Lien, YH (2008), "Is bowel preparation before colonoscopy a risky business for the kidney?", Nature Clinical Practice Nephrology, 4 (11): 606–14, doi:10.1038/ncpneph0939, PMID 18797448.
| Sodium compounds | |||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Inorganic |
| ||||||||||||||
| Organic | |||||||||||||||