Calcium Phosphate

Tricalcium phosphate; precipitated calcium phosphate
calcium hydroxyapatite
ca3(po4)2 formula wt 310.18
ca5oh(po4)3 formula wt 502.31
ca10(oh)2(po4)6 formula wt 1004.61
ins: 341(iii) cas: [7758-87-4]
cas: [1306-06-5
cas: [62974-97-4]
description
calcium phosphate, tribasic, occurs as a white powder that is stable in air. It consists of a variable mixture of calcium phosphates. It is insoluble in alcohol and almost insoluble in water, but it dissolves readily in dilute hydrochloric and nitric acids.
Function: ant caking agent; buffer; nutrient; clouding agent.
Requirements
identification
a. Add ammonium molybdate ts to a warm solution of sample in a slight excess of nitric acid. A yellow precipitate forms.
B. Dissolve about 100 mg of sample by warming it with 5 ml of 2.7 n hydrochloric acid and 5 ml of water; while shaking, add 1 ml of 6 n ammonium hydroxide, drop-wise and then add 5 ml of ammonium oxalate ts. A white precipitate forms.
Assay: not less than 34.0% and not more than 40.0% of calcium (ca).
Arsenic: not more than 3 mgkg.
Fluoride: not more than 0.0075%.
Lead: not more than 2 mgkg.
Loss on ignition: not more than 10.0%
tribasic calcium phosphate usp
tribasic calcium phosphate
ca5(oh)(po4)3 502.31
calcium hydroxide phosphate (ca5(oh)(po4)3).
Calcium hydroxide phosphate (ca5(oh)(po4)3) [12167-74-7].
tribasic calcium phosphate consists of a variable mixture of calcium phosphates having the approximate composition 10cao·3p2o5·h2o. It contains not less than 34.0 percent and not more than 40.0 percent of calcium (ca).
identification—
a: to a warm solution in a slight excess of nitric acid add ammonium molybdate ts: a yellow precipitate is formed.
B: it responds to the flame test for calcium.
Loss on ignition— ignite it at 800 for 30 minutes: it loses not more than 8.0% of its weight.