• Members of the previous forum can retrieve their temporary password here, (login and check your PM).

Novel??? Recrystalization Purification Techniques

Migrated topic.
olderROM

olderROM

Alfred
Basically someone who is not me figured out a way to consistently recrystallize with a distinct sharp separation between "clear crystal" and an "orange blob." I don't think this is novel, but if your interested in how it's done, I can spill the beans.

The novel part would be in the first pic. Basically those are cotton balls with orange contaminants in them. As shown in the other pics, you remove/save the clear crystals and do a little 'willy nilly' with on the "orange blob" and cotton... then you recrystallize and you'll have what you had before except a lot of the dark contaminants will be left on the cotton. The orange blob will be smaller and you'll have more clear crystals. Repeat, repeat, repeat!

Anyone heard of something like this??? Using cotton to retain/remove undesirables...



Feel free to ask questions...
 

Attachments

  • c6.JPG
    c6.JPG
    1.3 MB · Views: 1
  • d102.JPG
    d102.JPG
    4.6 MB · Views: 1
  • e115.JPG
    e115.JPG
    2.1 MB · Views: 1
  • e113.JPG
    e113.JPG
    1.2 MB · Views: 1
Using no solvent, heat up your crystals until they melt... add cotton balls until all the goo is absorbed. The cotton balls will remain dark after you've removed the DMT with solvent... as long as you're using a good solvent like heptane or naphta.
 
olderROM said:
Using no solvent, heat up your crystals until they melt... add cotton balls until all the goo is absorbed. The cotton balls will remain dark after you've removed the DMT with solvent... as long as you're using a good solvent like heptane or naphta.
Click to expand...
Very interesting altogether...!

So you melt the coloured dmt, then you adsorb it onto the cotton...and then you soak the cotton in warm naphtha which takes up the dmt but leaves the coloured stuff behind, right?

If yes, how is it different from recrystallisation with warm naphtha where the coloured impurities just sink on the bottom? Could you use another solvent like ethanol or acetone to the same effect? Would soaking the coloured, "waste" cotton balls in ethanol or acetone remove their colour or are the coloured contaminants impregnated forever in the cotton?
 
Simple enough but seems like a bloody good idea. Impurities which sink to the bottom of the redissolve jar don't always stay there. I believe it takes patience to wait for it all to settle and separating it off so gently may not be as reliable as trapping insoluble material in cotton.
 
This is incredibly interesting. First I would like to thank you, or swim or whoever, for figuring this out. It's a method I may actually employ for other compounds.
 
This is genius. Basically chromatography on a very small and efficient scale. DMT is very nonpolar and therefore doesn't adsorb on the cotton as much as other substances.

As to getting rid of the orange stuff: Activated charcoal works very good. Just add one spatula full of activated charcoal, mix and let sit for a few minutes and then filter with a very slow filter (small pores) to get rid of the charcoal and orange/yellow impurities.

Combined these two methods could prove very efficient in cleaning up product.
 
Infundibulum said:
So you melt the coloured dmt, then you adsorb it onto the cotton...and then you soak the cotton in warm naphtha which takes up the dmt but leaves the coloured stuff behind, right
Click to expand...
Yes


Infundibulum said:
If yes, how is it different from recrystallisation with warm naphtha where the coloured impurities just sink on the bottom?
Click to expand...
SWIM can always get more white crystals out of those coloured blobs. So, he was trying to find a way to clean up that coloured blob because he knows there are a lot of goodies in it!


Infundibulum said:
Could you use another solvent like ethanol or acetone to the same effect? Would soaking the coloured, "waste" cotton balls in ethanol or acetone remove their colour or are the coloured contaminants impregnated forever in the cotton?
Click to expand...
No, ethanol and acetone dissolve the dark compounds that the cotton catches.
 
nigl said:
As to getting rid of the orange stuff: Activated charcoal works very good. Just add one spatula full of activated charcoal, mix and let sit for a few minutes and then filter with a very slow filter (small pores) to get rid of the charcoal and orange/yellow impurities.

Combined these two methods could prove very efficient in cleaning up product.
Click to expand...
Thanks, SWIM hasn't tried this method yet.



Thank for the responses. SWIM hopes this method works well for others... =)
 
benzyme said:
this is similar in principle to SPE (solid phase extraction), where the solid [crude] analyte is adsorbed onto a stationary phase, and eluted with a solvent. in this case, cellulose is the stationary phase.
large molecules which participate in H-bond interactions will adhere to the cellulose, and nonpolar small molecules will readily elute.
Click to expand...

I prefer not to heat up the dmt any more than necessary. Would it work to dissolve the dmt in a non polar solvent first, and then add the cotton balls? Or would the impurities not want to ''jump'' over to the cotton at that stage?
 
Cool idea.

Here's a little twist on that to maximize yield and quality (little more complicated though)

1. Dissolve dmt goo in highly soluble solvent (suggestions?)
2. Evaporate solvent in a dish containing cotton
3. Pack column (small amount of cotton - sand - cotton - dmt containing cotton)
4. Run hot solvent (heptane or naptha)
5. Collect solvent
6. Evap/reX
7. Enjoy!

Only thing I would be weary about when trying this is how fast the solvent runs through the column. Chromatography can take FOREVER if you pack the column too tightly.
 
Interesting. Seeing as paper also consists (largely) of cellulose fibres, a rolled up sheet of kitchen towel - as sometimes used in funnels for filtration - should also do the trick. We then have a variant of paper chromatography which may work after a fashion for preparative purposes in this particular context. PPCC - Preparative Paper Column Chromatography :S
 
Expanding on this, I've had pretty good luck loading the cotton ball into a 50ml syringe and pumping boiling heptane though it a few times. Simply using the syringe as a diaphram against the hot solvent. G
 
1ce said:
Expanding on this, I've had pretty good luck loading the cotton ball into a 50ml syringe and pumping boiling heptane though it a few times. Simply using the syringe as a diaphram against the hot solvent. G
Click to expand...

Might try this next time as my bark is ultra fine and it's very hard to not help pulling even the smallest amount of dust & congealing fats ...
 
Using this, I removed the syringe plunger, stuffed the cotton ball down at the end, and poured the solvent down the top like a column. I had my crystalizing dish in a heatbath. The excess solvent ran out of the syringe tip and into the dish where I loaded the plunger and pumped the solvent out.

This makes me really curious, extracting with naptha tends to lead to more fats being pulled, true. But I wonder if preparing a syringe with a cotton ball or two and using the above method would bring out a cleaner end product.

I'm actually about to basify and extract now, I'll try that this time and post back on the results!
 
Back
Top Bottom