A “Reference” Precipitated Tricalciurn Phosphate Hydrate

Tricalcium phosphate as an adsorbent in the chromatography of proteins

“…Hydrated tricalcium phosphate was prepared by the slow addition of conc. H3P04 to a chilled solution of a calcium complex of sucrose, according to a method developed by Maclntire, Palmer & Marshall (1945). To 450 g. pure sucrose in 2 1, of water were added 75 g. CaO prepared by calcining 150 g. of precipitated CaCO3 at 10000 for 3 hr.…”

Phosphate Solubility, Evaluation of Water-Insoluble Phosphorus in Fertilizers by Extraction with Alkaline Ammonium Citrate Solutions

“…of water, and the water-insoluble residue is extracted with 100 ml. of the Petermann reagent for 1 5 hours at room temperature and 1 hour at 40°C. Aliquots of the water and citrate extracts are combined for phosphorus determination.…”

“…The solubility of the basic calcium phosphate in neutral and in alkaline ammonium citrate agrees very closely with the values determined by Ando for hydroxyapatite (2). Maclntire (5) found that the solubility in neutral ammonium citrate of four preparations of hydroxyapatite varied from 35 to 53% when using 1 gram of charge and 100 ml. The solubility in alkaline ammonium citrate of the water-insoluble phosphorus content of eight samples of nitric phosphates ranged from 72 to 99%.…”

“…Even the more soluble, well granulated phosphorus carriers such as concentrated superphosphate and ammonium phosphates lose a large part of their phosphorus after 12 to 24 hours of exposure to moist soil (5,6).…”

History of Calcium Phosphates in Regenerative Medicine

“…Nevertheless, papers on precipitated TCP [174,175] and even on precipitated TCP hydrate [176] kept publishing even in the 1940s. An interesting distinction between HA and precipitated TCP hydrate (obviously, it was CDHA with x D 1; see Table 15.1) was made in a latter paper [176]: "It seems safe to conclude that a precipitated tricalcium phosphate can be designated as a hydroxyapatite when a 1-gram charge of 900 ºC. calcine registers a dissolubility of less than 20 % by a continuously agitated 1-hour digestion in the ammonium citrate reagent at 65 ºC.…”