Sodium phosphate
A sodium phosphate is a generic variety of
Uses
Sodium phosphates have many applications in food and for water treatment. For example, sodium phosphates are often used as
Adverse effects
Sodium phosphates are popular in commerce in part because they are inexpensive and because they are nontoxic at normal levels of consumption.
Monophosphates
Three families of sodium monophosphates are common, those derived from orthophosphate (PO3−4), hydrogen phosphate (HPO2−4), and dihydrogenphosphate (H2PO−4). Some of the best known salts are shown in the following table.
name | formula | CAS registry number
|
---|---|---|
monosodium phosphate (anhydrous) | NaH2PO4 | 7558-80-7 |
monosodium phosphate monohydrate | NaH2PO4·H2O | 10049-21-5 |
monosodium phosphate dihydrate | NaH2PO4·2H2O | 13472-35-0 |
disodium phosphate (anhydrous) | Na2HPO4 | 7558-79-4 |
disodium phosphate dihydrate | Na2HPO4·2H2O | 10028-24-7 |
disodium phosphate heptahydrate | Na2HPO4·7H2O | 7782-85-6 |
disodium phosphate octahydrate | Na2HPO4·8H2O | |
disodium phosphate dodecahydrate | Na2HPO4·12H2O | 10039-32-4 |
trisodium phosphate (anhydrous, hexagonal) | Na3PO4 | |
trisodium phosphate (anhydrous, cubic) | Na3PO4 | 7601-54-9 |
trisodium phosphate hemihydrate | Na3PO4·0.5H2O | |
trisodium phosphate hexahydrate | Na3PO4·6H2O | |
trisodium phosphate octahydrate | Na3PO4·8H2O | |
trisodium phosphate dodecahydrate | Na3PO4·12H2O | 10101-89-0 |
Di- and polyphosphates
In addition to these phosphates, sodium forms a number of useful salts with pyrophosphates (also called diphosphates), triphosphates and high polymers. Of these salts, those of the diphosphates are particularly common commercially.
name | formula | CAS Registry number |
---|---|---|
monosodium diphosphate (anhydrous) | NaH3P2O7 | |
disodium diphosphate (anhydrous) |
Na2H2P2O7 | 7758-16-9 |
disodium diphosphate hexahydrate | Na2H2P2O7·6H2O | |
trisodium diphosphate (anhydrous) | Na3HP2O7 | |
trisodium diphosphate monohydrate | Na3HP2O7·H2O | |
trisodium diphosphate nonahydrate | Na3HP2O7·9H2O | |
tetrasodium diphosphate (anhydrous) |
Na4P2O7 | 7722-88-5 |
tetrasodium diphosphate decahydrate | Na4P2O7·10H2O | 13472-36-1 |
Beyond the diphosphates, sodium salts are known triphosphates, e.g. sodium triphosphate and tetraphosphates. The cyclic polyphosphates, called metaphosphates, include the trimer sodium trimetaphosphate and the tetramer, Na3P3O9 and Na4P4O12, respectively.
Polymeric sodium phosphates are formed upon heating mixtures of NaH2PO4 and Na2HPO4, which induces a condensation reaction. The specific polyphosphate generated depends on the details of the heating and annealing. One derivative is the glassy (i.e., amorphous) Graham's salt (sodium hexametaphosphate). It is a cyclic polyphosphate with the formula Na6[(PO3)6]. Crystalline high molecular weight polyphosphates include Kurrol's salt and Maddrell's salt (CAS#10361-03-2). These species have the formula [NaPO3]n[NaPO3(OH)]2 where n can be as great as 2000, and it is a white powder practically insoluble in water. In terms of their structures, these polymers consist of PO−3 units, with the chains are terminated by protonated phosphates.[1][7]
References
- ^ ISBN 978-3527306732.
- ^ "Monosodium Phosphate | Sodium Phosphate Formula". Archived from the original on 2015-04-02.
- S2CID 206223856.
- PMID 20958267.
- ^
Markawitz, GB; Parezelli, MA (Aug 12, 2007), "Acute Phosphate Nephropathyl", Kidney Int., vol. 76, no. 10, pp. 1027–34, PMID 19675530
- ^
Mackey, AC; Breen, L; Amand, KS; Evigan, M (August 2007), "Sodium phosphate tablets and acute Phosphate Nephropathy", Am J Gastroenterol, vol. 104, no. 8, pp. 1903–6, S2CID 12551005
- ISBN 978-0-08-037941-8.
External links
- US 3726960, Bell, Russel N, "Sodium Aluminum Phosphate Cheese Emulsifying Agent", published 1973
- Lien, YH (16 July 2008). "Is bowel preparation before colonoscopy a risky business for the kidney?". Nature Clinical Practice Nephrology. 4 (11): 606–14. S2CID 340122.