Sodium pyrophosphate
1671205
212973461
2008-05-17T03:25:11Z
75.3.15.107
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| ImageFile = Sodium pyrophosphate.png
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| IUPACName =
| OtherNames = tetrasodium pyrophosphate, tetrasodium phosphate
| Section1 = {{Chembox Identifiers
| CASNo = 7722-88-5
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| Section2 = {{Chembox Properties
| Formula = Na<sub>4</sub>P<sub>2</sub>O<sub>7</sub>
| MolarMass = 265.90 g/mol
| Appearance = Colourless crystals
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| Section3 = {{Chembox Hazards
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'''Sodium pyrophosphate''', also called '''tetrasodium pyrophosphate''' or '''tetrasodium phosphate''', is a slightly [[toxic]] and mildly [[irritant|irritating]] [[color]]less [[Transparency (optics)|transparent]] [[crystalline]] [[chemical compound]] with the [[chemical formula|formula]] {{sodium}}<sub>4</sub>{{phosphorus}}<sub>2</sub>{{oxygen}}<sub>7</sub> and [[CAS number]] 7722-88-5. It contains the [[pyrophosphate]] [[ion]]. Toxicity is approximately twice that of [[table salt]] when digested orally.<ref>http://books.google.com/books?id=Mk-IdNTTJB0C&pg=PA259&lpg=PA259&dq=tetrasodium+phosphate+toxicity&source=web&ots=UTcG2wT0y9&sig=_c9T9HRdwiV7pMk01T8ZLTzFkl8#PPA260,M1</ref>. There is a hydrated form, Na<sub>4</sub>P<sub>2</sub>O<sub>7</sub>.10(H<sub>2</sub>O) which has the [[CAS number]] 13472-36-1.<ref name = “Perry”> D.L. Perry S.L. Phillips (1995) ''Handbook of inorganic compounds'' CRC Press ISBN 0849386713</ref>
Sodium pyrophosphate is used as a [[buffering agent]], an [[emulsifier]], and a [[thickening agent]], and is often used as a [[food additive]]. Common [[food]]s containing sodium pyrophosphate include [[chicken nugget]]s, [[marshmallows]], [[pudding]], [[crab]] meat, [[imitation crab]], canned [[tuna]], and [[soy]]-based [[meat]] alternatives. It is the active ingredient in Bakewell, the substitute for baking powder's acid component marketed during shortages in World War II.
In [[toothpaste]], sodium pyrophosphate acts as a [[tartar]] control agent, serving to remove [[calcium]] and [[magnesium]] from [[saliva]] and thus preventing them from being deposited on [[teeth]]. Sodium pyrophosphate is sometimes used in household [[detergent]]s to prevent similar deposition on [[clothing]], but due to its [[phosphate]] content it causes [[eutrophication]] of [[water]], promoting [[algae]] growth.
Sodium pyrophosphate is the crystal deposited in joints in the medical condition [[pseudogout]].<ref>Clinical Medicine, Kumar and Clark, 6th Ed., p. 571</ref>
== See also ==
* [[Disodium pyrophosphate]]
* [[pseudogout]]
* [[food allergy]]
==References==
<references/>
[[Category:Sodium compounds]]
[[Category:Pyrophosphates]]
[[Category:Food additives]]
[[ar:بيروفوسفات صوديوم]]
[[de:Tetranatriumdiphosphat]]
[[pt:Pirofosfato de sódio]]