Recrystallization to check purity?

[kozybe]

Got a question for anyone that can chime in? There's lots of talk around here about labmax to check if your powder is legit, but nothing to check for purity(except ms). What about recrystallization of your powder? If you just weighed your powder before the process, recrystallized, dried, and weighed after? The process should purify the powder anyways as that's the whole purpose of the process. What do you guys think?

 

[ATodd]

Got a question for anyone that can chime in? There's lots of talk around here about labmax to check if your powder is legit, but nothing to check for purity(except ms). What about recrystallization of your powder? If you just weighed your powder before the process, recrystallized, dried, and weighed after? The process should purify the powder anyways as that's the whole purpose of the process. What do you guys think?

Not quite sure how that would work. If you melted the powder and noted the temp. and it's the same for the charateristic m.p. of what you are looking for, it's the substance in question Probably). If it's more that compound mixed you would register a melting point that is almost always lower than either of the individual components. Im not sure how you would purify the substance by heating it unless you bring it to boil and distill the compound.

 

[kozybe]

Thanks for the reply ATodd. I understand the melting point test will determine if a compound is what it is, but if there were some impurities in the powder would it effect that test? Also I was referring to the recrystallizing process in which you use methanol alcohol to dissolve the powder and then distilled water to super saturate the solution and create pure crystals of the compound. Then filter, rinse, and dry. It seems that if you weigh the powder before and after the difference weight would tell you how much impurities came out during the process. For example, if you weighed 10 grams of powder and got 9 grams of crystals after you would have 90% purity. Just curious if this makes sense to anyone?

 

[mousetrapped]

This does make sense but I think you have to consider what the adulterant is, assuming there is one. I've not tested the purity of my powder source because so far I haven't had the means to (that will change soon I hope) but lets assume that it's not 100% pure. When I mix the gear into its solvent (oil, ethyl oleate, etc) the adulterant should not dissolve, it should sink to the bottom, unless of course it too is soluble in the solvent I'm using. SO, when you go to do your crystallization, you're going to be catching the adulterant along with the actual hormone wouldn't you? Also, how is distilled water going to super saturate the solution?

I guess you could try mixing the hormone in several different solvents in an effort to find one that the adulterant is not soluble in but I think you're going to have really mixed results that and it would probably be a lot more difficult and expensive than just paying a lab to have mass spec done.

Finally I guess you could get an IDEA from the quality of the crystals that grow, but then assumes you have done several recrystalizations and dry in a completely dry atmosphere. If you still get powder or tiny crystals at that point then you know its not pure, but I mean realistically I'm not expecting it to be pure and what I want to know is HOW unpure it is.