Calcium phosphate
Calcium phosphate is the name given to a family of minerals containing calcium ions (Ca2+) together with orthophosphates (PO43-), metaphosphates or pyrophosphates (P2O74-) and occasionally hydrogen or hydroxide ions.
Varieties of Calcium Phosphate
| Tricalcium phosphate | Ca3(PO4)2 (occurs in alpha and beta phases; beta also known as Whitlockite) |
| Calcium monohydrogen phosphate | CaHPO4 |
| Calcium dihydrogen phosphate | Ca(H2PO4)2 |
| Calcium pyrophosphate | Ca2P2O7 (occurs as alpha, beta and gamma phases) |
| Hydroxylapatite | Ca10(PO4)6(OH)2 |
Natural Abundance
It is found in nature as a rock in Morocco, Israel, Egypt, and Kola (Russia) and in smaller quantities in some other countries. The natural form is not completely pure, and there are some other components like sand and lime which can change the composition. In terms of P2O5, most calcium phosphate rocks have a content of 30 % to 40 % P2O5 in weight.
The skeletons and teeth of vertebrate animals are composed of calcium phosphate, mainly hydroxylapatite.
Uses
Calcium phosphate is an important raw material for the production of phosphoric acid and fertilizers, for example in the Odda process.
Calcium phosphate is also a raising agent (food additives) E341. Is a mineral salt found in rocks and bones, it is used in cheese products. No known side effects.
Another practical application of the compound is its use in gene transfection. The Calcium ions can make a cell competent (a euphemism for "rip holes in its membrane") to allow exogenous genes to enter the cell by diffusion. A heat shock afterwards then invokes the cell to repair itself. This is a quick and easy method for transfection, albeit a rather inefficient one.