How to do cold water extractions?

[jrey]

Can someone remind me how to do a cold water extraction? I used to do it all the time a decade ago back in high school but I completely forgot the pill to water ratio and how long to put it in the freezer for. I am going to use norcos 10/325. I am trying to do a CWE on 20-30 of them.

 

[F.U.B.A.R.]

The solubility of acetaminophen is quoted as 1 - 5mg per ml of water at 72°F.

Acetaminophen

Acetaminophen | C8H9NO2 | CID 1983 - structure, chemical names, physical and chemical properties, classification, patents, literature, biological activities, safety/hazards/toxicity information, supplier lists, and more.

pubchem.ncbi.nlm.nih.gov

Therefore, even if you used 100ml of water at room temperature the maximum amount of acetaminophen you could end up with in your final product is 500mg. This will be considerably less if you use refrigerated water. As codeine is more soluble, this will dissolve first leaving even less room for the acetaminophen.

So you physically cannot end up with a solution containing enough acetaminophen to be of concern.

I personally can't see the point of the freezer step. It takes too fuckin long.

I would crush the pills into a fine powder, mix thoroughly into 50ml water and stir for a couple minutes.

Then perform a course filtration. I use a piece of kitchen paper on top of a J cloth (both pre-wetted to eliminate absorption of the goodies).

Drape the filter over a suitable wide necked receptacle and make a depression in the middle. Pour the sludgy mixture into the middle of the filter, gather up the sides of the J cloth and squeeze the liquid through. The J cloth prevents the finer pored kitchen paper from tearing during the operation. Although squeezing the pre-wetted filter will introduce more water, it's still not enough to do you any harm. This will leave you with a cloudy solution in the receptacle and a dryish paste consisting mainly of acetaminophen, fillers and binders in the filter.

Then take the cloudy solution and filter again through a pre-wetted coffee filter. The absence of the fillers and binders makes this a relatively quick process. Even if the resulting filtrate is not perfectly clear, you're still good to go.

This operation can be completed in 10 minutes as opposed to waiting for freezing and settling and gives the same result.

 

[Keif' Richards]

The solubility of acetaminophen is quoted as 1 - 5mg per ml of water at 72°F.

Acetaminophen

Acetaminophen | C8H9NO2 | CID 1983 - structure, chemical names, physical and chemical properties, classification, patents, literature, biological activities, safety/hazards/toxicity information, supplier lists, and more.

pubchem.ncbi.nlm.nih.gov

Therefore, even if you used 100ml of water at room temperature the maximum amount of acetaminophen you could end up with in your final product is 500mg. This will be considerably less if you use refrigerated water. As codeine is more soluble, this will dissolve first leaving even less room for the acetaminophen.

So you physically cannot end up with a solution containing enough acetaminophen to be of concern.

I personally can't see the point of the freezer step. It takes too fuckin long.

I would crush the pills into a fine powder, mix thoroughly into 50ml water and stir for a couple minutes.

Then perform a course filtration. I use a piece of kitchen paper on top of a J cloth (both pre-wetted to eliminate absorption of the goodies).

Drape the filter over a suitable wide necked receptacle and make a depression in the middle. Pour the sludgy mixture into the middle of the filter, gather up the sides of the J cloth and squeeze the liquid through. The J cloth prevents the finer pored kitchen paper from tearing during the operation. Although squeezing the pre-wetted filter will introduce more water, it's still not enough to do you any harm. This will leave you with a cloudy solution in the receptacle and a dryish paste consisting mainly of acetaminophen, fillers and binders in the filter.

Then take the cloudy solution and filter again through a pre-wetted coffee filter. The absence of the fillers and binders makes this a relatively quick process. Even if the resulting filtrate is not perfectly clear, you're still good to go.

This operation can be completed in 10 minutes as opposed to waiting for freezing and settling and gives the same result.

Major thanks to FUBAR for the explanation and the link. This should explain everything in pretty clear terms. Just let us know if there is anything you dont understand OP!

Good luck

 

[F.U.B.A.R.]

What is strange is that the equivalent pubchem listing for codeine now quotes the solubility of codeine as "less than 1mg/ml at 70°F" This now seems to be saying that codeine is far LESS soluble than acetaminophen - which is not the case at all.

Codeine

Codeine | C18H21NO3 | CID 5284371 - structure, chemical names, physical and chemical properties, classification, patents, literature, biological activities, safety/hazards/toxicity information, supplier lists, and more.

pubchem.ncbi.nlm.nih.gov

I'm sure this has been doctored. I have used pubchem to check codeine solubility many times in the past and it always used to state 120mg/ml @ 70°F.

In fact, it now seems to be relatively difficult to find a definitive figure for the solubility of codeine in water. It even used to be stated in the Wikipedia entry, but is now missing. Hmm, I wonder why..?

Here's a pdf download that states the true figure of 120mg/ml.

Error - Cookies Turned Off

onlinelibrary.wiley.com

This disparity is quite sinister because anyone taking pubchem at their word could end up using an excessive amount of water to perform a CWE thus inadvertently dissolving far too much acetaminophen in the process.

 

[Keif' Richards]

Yes, that is interesting that there is such a difference in the data. Like FUBAR said, we are aware that Codeine is far more soluble than what pubchem is apparently implying.

So I would just recommend ignoring that and moving on with your CWE.

 

[Kaden_Nite]

What is strange is that the equivalent pubchem listing for codeine now quotes the solubility of codeine as "less than 1mg/ml at 70°F" This now seems to be saying that codeine is far LESS soluble than acetaminophen - which is not the case at all.

Codeine

Codeine | C18H21NO3 | CID 5284371 - structure, chemical names, physical and chemical properties, classification, patents, literature, biological activities, safety/hazards/toxicity information, supplier lists, and more.

pubchem.ncbi.nlm.nih.gov

I'm sure this has been doctored. I have used pubchem to check codeine solubility many times in the past and it always used to state 120mg/ml @ 70°F.

In fact, it now seems to be relatively difficult to find a definitive figure for the solubility of codeine in water. It even used to be stated in the Wikipedia entry, but is now missing. Hmm, I wonder why..?

Here's a pdf download that states the true figure of 120mg/ml.

Error - Cookies Turned Off

onlinelibrary.wiley.com

This disparity is quite sinister because anyone taking pubchem at their word could end up using an excessive amount of water to perform a CWE thus inadvertently dissolving far too much acetaminophen in the process.

The article for 'Codeine' seemingly refers specifically to codeine base.

The 'Codeine Phosphate' article lists solubility as equal or greater than 100 milligrams in 1 millilitre of water.

 

[F.U.B.A.R.]

The article for 'Codeine' seemingly refers specifically to codeine base.

The 'Codeine Phosphate' article lists solubility as equal or greater than 100 milligrams in 1 millilitre of water.

Ah, thank you. That clears that up.


Schoolboy error...

 

[Keif' Richards]

The article for 'Codeine' seemingly refers specifically to codeine base.

The 'Codeine Phosphate' article lists solubility as equal or greater than 100 milligrams in 1 millilitre of water.

Ah, I see. Thanks for clearing that up buddy.