alchemizt
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Good solvent for liquid liquid extraction of curcuminoids
I made an extract of turmeric with 96% ethanol and evaporated the solvent at room temperate with a fan. The solvent won't evaporate completely due to
the water. I'm thinking of using a liquid liquid extraction to separate the oil and curcuminoids from the water. Acetone is well known to be
exceptionally good for dissolving curcuminoids, but its miscible with water. Would ethyl acetate be the next best thing?
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Boffis
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That's not the way to go! Dry over calcium chloride or sulphuric acid etc and then leach the residue with petroleum ether/ cyclohexane etc to remove
fats and oils and then recrystallise from a hot alcohol. I can't remember which alcohol I used and I am not at home to check my notes but it does make
a difference. This latter process gives you fairly pure curcumin and a residue that contains at least 3 well crystallised substances.
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unionised
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It probably isn't water.
There are fats and oils in the spice and those will have been extracted along with the curcumin.
As Boffis has pointed out, you can remove them by extraction with pet ether (and you can use zippo fuel if you don't have access to pet ether).
That takes care of the fats.
But there will still be other things present- notably sugars.
a wash with water will remove them- though there will be some (small) loss of curcumin.
Recrystallisation is still a good plan.
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alchemizt
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Quote: Originally posted by Boffis  | | That's not the way to go! Dry over calcium chloride or sulphuric acid etc and then leach the residue with petroleum ether/ cyclohexane etc to remove
fats and oils and then recrystallise from a hot alcohol. I can't remember which alcohol I used and I am not at home to check my notes but it does make
a difference. This latter process gives you fairly pure curcumin and a residue that contains at least 3 well crystallised substances.
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I actually wanted to isolate the oleoresin (mix of curcuminoids and essential oil) and save some of that, then separate the curcuminoids from that.
Does the alcohol recrystallisation give you pure curcumin or a mix of 3 curcuminoids?
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pneumatician
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Mood: ■■■■■■■■■■ INRI ■■■■■■■■■■ ** Igne Natura Renovatur Integra **
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freezer??
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