Sciencemadness Discussion Board

Water/Ethanol - Recrystalization - A reccuring problem I'm having

Chemstudent - 19-4-2012 at 08:10

Okay, I understand fully the concept behind recrystallization. The compound in question is Trenbolone Acetate CAS: 10161-34-9
This is a steroid hormone. The following is some accurate information. This originally started as a project to some other ends, some may have seen Trenbolone Acetate prepared for injection from Finaplix cattle implants in the bodybuilding community. Indeed this is what the end was, but now I could care less about that. I have not been able to recrystallize this hormone, it has driven me mad! It defies me, and if I cannot fix this then I surely have a weak understanding of recrystallization! >:( I'm obsessed now! I must find a solution!

Molar Solubility Sparingly Soluble (1.0E-5 mol/L) Unbuffered Water pH 7.00 Temp: 25 °C
Boiling Point 486.7±45.0 °C
Enthalpy of Vaporization 75.25±3.0 kJ/mol
Density 1.18±0.1 g/cm3
Melting Point 96-97 °C

With all this in mind, I set out to begin my recrystallization. Here is the order of operations that has led me to where I am now.

1.) Ground down sample of 100 small cattle pellets containing desired product.

2.) A small pile of 2-3 or so grams estimated was recovered (I have no budget yet for a qualitative scale, yes I know its of utmost importance to have one).

3.) A brown coffee filter was set up in a plastic kitchenware funnel on a ring stand. A 250mL vial of Ethanol obtained from double distillation of Rum was set to simmer on a hot plate. 5mL of Ethanol (unknown purity, but darn good moonshine if you ask me) was sprayed into the filter so as to wet it's surface.

4.) In the funnel went the 2-3 grams of Trenbolone Acetate + Methylcellulose powder. Over that I poured precisely 15mL of HOT ethanol. A final 5ml was poured over, and left behind was an off yellow white gunk (which I assume was the methyl-cellulose binder w/ other impurities)

5.) The receiving flask was heated, the product was fully dissolved into solution. The solution appeared yellow/clear (like urine from someone who took a b-100 pill for the first time).

6.) I then preceded to add in 5mL alloquats hot DI water. The solution went from yellow/clear to a distinct milky/off yellow. Eventually the solution turned completely milky and entirely opaque. Approx. 100mL of water was at that time added. During the time water was added the solution was under a heating element.

7.) I allowed sol. to come to room temp. then it was placed on an ice bath. Nothing.

8.) I boiled the solution (which btw took considerable more heat than to boil water, and took about 1hr to return to room temp) and nothing. The solution remained milky as ever, save for a very very small qty. of orange goop that coagulated and rose to the top. I filtered this small amount of goop while the sol. was still very hot over the same grav filtration setup w/ new filter but same method. The filter caught what appeared to be methyl cellulose binder, which I determined by drying it off and comparing it to the matter caught by my first filtration.

9.) So I added more water, hoping to drive the product out of solution. I again tried boiling, and still a milky white, adding 100mL more water proved useless and the opacity remained just the same. And now I have a flask 250mL containing Water/Ethanol + white particulate matter (the hormone).

I'm stuck! I simply do not know what I can do to remedy this situation. I MUST recrystallize this so I can walk away confident in my ability, I can't let myself just write this off as a bad experiment and never revisit, it mocks me!!! :(

I know lipid hormones are water insoluble, they simply do not form into solution in water. For ex: this is why we need LDL to transport Fat/Cholesterol/Hormones/fat-sol vitamins (and then doctors compare LDL to attilla the hun waging war on our arteries, but i digress).

What can I do? Use a desiccant? I'm affraid the organic compound (the hormone) will easily be absorbed. I even spent time on these bodybuilding type forums asking guys who have claimed to do this same recrystallization successfully. I'm wondering where I have gone wrong. It appears Ethanol/Water are poor solvents, and I would accept this except that many many folk have claimed to use water/Ethanol & water/Methanol quite successfully.

Your thoughts are greatly appreciated! Thank you :)

Nicodem - 19-4-2012 at 08:22

Quote: Originally posted by Chemstudent  
Okay, I understand fully the concept behind recrystallization. The compound in question is Trenbolone Acetate CAS: 10161-34-9
...

6.) I then preceded to add in 5mL alloquats hot DI water. The solution went from yellow/clear to a distinct milky/off yellow. Eventually the solution turned completely milky and entirely opaque. Approx. 100mL of water was at that time added. During the time water was added the solution was under a heating element.

What you describe is not a recrystallization. What you did is called precipitation with an antisolvent. Obviously, this rarely works by using water as the antisolvent on such a hydrophobic compound, so you observe the precipitation of a liquid phase (commonly called "oiling out").
You should either perform a crystallization or a recrystallization (depending on the state of your crude product). See Vogel's for details about these laboratory techniques.

GreenD - 19-4-2012 at 08:31

HELLO WIKIPEDIA!

"Methyl cellulose has a lower critical solution temperature (LCST) between 40°C and 50°C. At temperatures below the LCST, it is readily soluble in water; above the LCST, it is not soluble, which has a paradoxical effect that heating a saturated solution of methyl cellulose will turn it solid, because methyl cellulose will precipitate out"

You also do not understand the recrystallization idea.


5.) The receiving flask was heated, the product was fully dissolved into solution. The solution appeared yellow/clear (like urine from someone who took a b-100 pill for the first time).

6.) I then preceded to add in 5mL alloquats hot DI water. The solution went from yellow/clear to a distinct milky/off yellow. [STOP!!! You went too far already] Eventually the solution turned completely milky and entirely opaque. Approx. 100mL of water was at that time added. During the time water was added the solution was under a heating element.

When you add your "bad" solvent (water) you add it hot until you JUST BARELY see a cloudiness appear. When you drop your little droplet of hot water, watch the solution, do you see the cloud form, then quickly disappear?

Continue to do this until the cloud just barely, barely disappears, and the solution is just BARELY transparent still.

Then let cool.

The problem here is that Methyl-cellulose is annoying. It will swell with water and probably make a pretty shitty/hard to extract solution.

My first approach to this (I'm still learning) would be to dissolve the pills overnight in RT water. Let them chill out while you sleep. Come back to the solution the next day. one of two things will occur:
1. The pills will swell somewhat, making a gel, and you will have an oil (or ppt) either on top or bottom or dispersed in between.
or
2. The pills will swell and the entire thing will be homogenous.

If 1: See if you can't decant with a small sep funnel or the plastic bag method
If 2: Heat up the solution. The methyl cellulos will ppt out, and hopefully filtration of the hot solution will give you your desired product. Upon cooling, the solid should ppt out again.


[Edited on 19-4-2012 by GreenD]

Chemstudent - 19-4-2012 at 11:06

It seems to me that Methyl-Cellulose is a tricky compound to work around. The hormone itself should be a rather simple compound to work with since most hormones are all quite water insoluble and do not mix well in many polar solvents while they dissolve well enough in polar solvents. It was apparent to me that this particular compound disolved very well in Ethanol, not a good candidate for recrystalization. However in water it appeared to me slightly soluble just as was stated on the CAS index sheet. So there I was, stuck between what bodybuilders on some website said would for sure work (water/ethanol) and me knowing full well that a solvent must either fully dissolve the compound or precipitate it fully, slightly soluble in a solvent does not cut it. I went ahead with the Ethanol/Water precipitation because I had to assume Water and Ethanol would seek each other out more strongly and give up the organic compound (the steroid). It seemed to follow the logic of salting out a compound only this would be liquid-liquid miscability than solid-liquid density change.

So my current situation: 250mL of water/ethanol/precipitate. I'm thinking of a few options to recover the precipitate as dry crystals. At the moment there is too great of a water concentration. I'm thinking I must simmer off a good 150-200mL liquid, if I simmer off too much water the cellulose and hormone will likely melt and burn. If and I assume none of the precipitate is damaged or left in the atmosphere, I should now have around 50mL of the precipitate on heat, I can let the solution continue to simmer off more and then try all over again to add alcohol until pprecipitate dissolves fully, then cool and see if crystals form. Or I can just take the 50mL solution of precipitate and filter off in a funnnel and see if product is left behind to dry. My last silly idea last ditch attempt was to have a separate flask filled with canola oil or some type of oil like cottonseed, then pour on top of the oil the precipitate solution and see if the product dissolves into the oil and leaves behind the other gunk in solution. From there I can more easily remove hormone from oil.

Has anyone else ever had a big issue with cellulose binders in a product they were trying to isolate? How is this normally dealt with?

GreenD - 20-4-2012 at 06:06

If its very soluble in ethanol, simply mash up the pills, let them sit in >90% ethanol over night. Decant off ethanol (don't throw anything away). Heat up ethanol, add COLD water.

Watch the drips, see if a cloudiness forms - it will only form if you've got a nearly saturated solution, so you will either have to use minimal ethanol, or evaporate some after you extract the analyte.

If you get cloudy drops, continue to drop the cold water in till the cloudiness just barely hangs on. Take off from heat. let cool to RT, any separation? Put in ice bath (salt water / Ice ) - separation/ppt?

You could also read anything I said above.

[Edited on 20-4-2012 by GreenD]

Chemstudent - 20-4-2012 at 10:12

I'm simmering off 200mL water as we speak. I'll drop the volume of fluid as much as possible until 10-20mL remains, then I'll bring the product back into solution with Ethanol and try to precipitate out the product with Water dropwise. I still don't see how this is supposed to work :( I get the concept of Ethanol/Water miscability and causing the compound to fall out of suspension, but it just doesn't seem to be working my way.

gutter_ca - 20-4-2012 at 10:47

"Well, I was trying to make juice, but now it's just science. Honest Injun."

Chemstudent - 20-4-2012 at 13:16

Quote: Originally posted by gutter_ca  
"Well, I was trying to make juice, but now it's just science. Honest Injun."


lol I was :p I had just one cart of finaplix left over and was very tempted to try the "recrystallization" method popularized on some bodybuilding forums. I figured if I loose just one pack to science no big deal. But now I'm frustrated as hell! How do some meat heads get it done right and now myself can't even work this out.

I crushed the pellets, I dissolved them in 20mL ethanol. All went into solution (well, dissolved as it was piss yellow). Then I drop-wise added some water while solution was hot and all I got was white/yellow milk. I cooled it, same thing. I added 150mL water,... same. Now I'm slowly boiling off all the water and trying again. :( Man, I even wrote up the procedure step by step all nicely organized in my notebook and recorded properties of the substance.

It mocks me now! I must find a solution.... to the solution