Does anyone happen to know the solubility of calcium phosphate and/or calcium carbonate in an aqueous solution?

Swim is sick of huffing gar fumes and stinking up the neighborhood with acetic acid vapors, so he's trying to find another way to salt out his alkaloids from his limo.

He found one source that sez: "Calcium carbonate has a solubility of 14 mg/L, which is multiplied by a factor five in presence of carbon dioxide. Calcium phosphate solubility is 20 mg/L.

(Source: http://www.lenntech.com/...-water.htm#ixzz0Ogxp7TNY)

It does not mention if the solubility of Calcium Phosphate is increased by the presence of CO2 the way Calcium Carbonate is.

Anyway Swim's original intention was to salt out alkaloids using an overly acidified solution of phosphoric acid, then precipitate the excess phosphoric acid with calcium carbonate, then filter out the calcium phosphate and residual calcium carbonate and evap the solution to reveal nearly pure phosphate salts of the alkaloids. This was based on a post from way back in the day on the old dmtworld forum by Loki, the same post that first suggested the possible use of limonene as an extraction solvent and got Swim to run the first ever limo experiments that have since led to this solvent becoming so popular here. But he never actually tried Loki's phosphate suggestion so he figured he'd give it a shot since if it worked, it would mean no more gar fumes during evap.

However, he just added some calcium carbonate to his alkaloid phosphate solution, and no precipitate is evident. It's like it all dissolved. So then he hopped online and found the above quote about the solubility (he had previously just assumed that Loki knew his stuff and that both calcium carbonate and calcium phosphare were insoluble in water).

Anyway even if the above statement is true, at a solubility rate of 20 mg/l, there still shouldn't be much calcium phosphate dissolved in Swim's little 50ml of solution, right? And yet it looks perfectly clear at the moment, no precipitate visible at all... not what swim was hoping for!

Now Swim's noticing a fizzing reaction going on, which is presumably CO2 gas being released as the calcium carbonate reacts with the phosphoric acid, releasing the carbon... right? So is the presence of the CO2 somehow making the stuff more soluble, and will that quit happening as the CO2 bubbles out, meaning the calcium phosphate and calcium carbonate will precipitate once the fizzing goes away? CO2 doesn't normally stay in water, does it?

If anyone can offer some thoughts or shed some light on what is going on here, Swim would really appreciate it. If we can get this to work right, this could be a major advancement in "green" extraction technology. Just imagine... no more gar fumes irritating the lungs and raising questions from the neighbors!

Thanks in advance for any help!

SyZ y GyPSy

Syzy, these are great ideas.

The reaction between calcium carbonate and phosphoric acid must be very slow as it seems from SWIY's observation.

Has SWIY tried to neutralise the phosphoric acid using Calcium hydroxide? This may be more promising and with more immediate results!