[lucifer87]

I am attempting to create a method for washing an extract of plant material with solvents in a biphasic setup. The slightly polar actives in said plant material are allegedly soluble in the following solvents at these quantities:

Acetone= 89.5% yield (of total active constituents)
Water= 78.5%
Chloroform= 71.9%
Methanol= 64.5%
Ethanol= 52.3%

Now the initial extract will definitely be done with pure Acetone and afterwards be seperated from the solvent with a standard evaporatory procedure. The impurities, one of which being starch which is present at above 30%, are quite soluble in the Acetone as well so I want to remove the more polar of said impurities with a solvent less suitable for extraction of my actives. I figured that since Ethanol has a similar polarity to water and only yields 52.3% compared to Chloroform's 71.9% that this would work if only the Ethanol wasn't so very miscible with the latter (which would not purify my extract very well). I have no idea, nor can I figure out Ethanol/Chloroform's miscibility. How miscible are they? Is there a way to modify the Ethanol to make it less miscible with Chloroform? Where can I find miscibility info online like this?

[Doc Oc]

Ethanol and chloroform are not miscible.

[Honclbrif]

http://webpub.allegheny.edu/employee/s/smurphre/research/miscibility.pdf

Ethanol is miscible with every common solvent.

If you're trying to remove sugar and starch on large scales (several grams), consider methods other than liquid-liquid extraction. I used to work in a lab that studied polyphenols from various fruits, and the way we removed sugars was with Diaion HP-20 resin. Take your initial acetone extract, vac out the solvent, and resuspend in minimal water. Apply it to a column of Diaion packed with distilled water, and flush with distilled water until the column runs clear (it may take several liters depending on how much material you are using). Elute with straight methanol.

[lucifer87]

^ Appreciate it bruh, only problem there is I still doubt my actives are very soluble in water because I've ran into a couple contradictions through my research and in order to efficiently suspend them in such I expect that I'd need to complex with cyclodextrin which I'm not sure would remove only actives. not only that, sugar accounts for about 3% so I'd consider that only if it removed other s#*$. I know I'm confusing saying water dissolves too much active material then stating the actives aren't suppose to be soluble in said water (what I've read everywhere else other than that one Japanese report) but I think that if perhaps I wrote someone a more private message it'd be easier to understand my problem since I don't wanna spill the beans on a public forum regarding the research I've done thus far as this is a fairly popular plant material and this thread would pop up in google searches. Anyway, I know that ethanol/chloroform is miscible but how much so? Where/how can I find this answer without trial and error (which I'm prepared to do if need be)? I'm thinking that since water/ethanol are miscible (cause they're both polar) and ethanol/chloroform are as well being that ethanol has a non-polar end too, that the ethanol would preferentially choose one of those two phases (water or chloroform). in a perfect situation the ethanol would go into both phases but moreso in the water since I know off tiggidy that ethanol/water are 100% miscible and then the amount of ethanol in the chloroform is HOPEFULLY minimal such that I wouldn't mind it's presence and the impurities that said ethanol would allow to piggy-back with it into my organic phase where my actives are would be somewhere near negligible. I'm thinking doing a 2:1 water-ethanol ratio in the above phase and a 1:2 water/ethanol-chloroform ratio such that any actives that want to swim in water/ethanol would just remain in the chloroform phase as it would have much less solute within. So Honclbrif, how can I contact you privately (if that’s alright with you)?

[lucifer87]

I guess I should just ask, "Will chloroform and ethanol form a homogenous mixture" and if not, what sort of a mole fraction should I expect? The Handbook of Separation Process Technology By Ronald W. Rousseau reads... "Ethanol-chloroform is highly asymetrical... the activity coefficient of chloroform shows a pronounced maximum at an ethanol mole fraction of about 0.85"... I am not studying chemistry so that is babble to me even after reading the wikipedia explanation of activity coefficient. I figured this meant that there is up to an 85% deviation from the ideal mixture which would have an enthalpy of zero. I'd appreciate an interpretation.

[lucifer87]

Oh, and Honclbrif... does starch also have an affinity for Diaion HP-20 resin as that would eliminate the need for the starch extraction with ammonium hydroxide and sodium bisulfite which I'm hesitant of being that those are serious compounds? Water and resin is preferable. Thanks sir.

[Honclbrif]

I'm not 100% on this as I was using it to remove simpler sugars, but I would assume that it would remove starch too. I'd look this up before buying anything though.

[lucifer87]

Honclbrif, I will seriously consider that. I’m thinking that my actives are probably bout the only allegedly “hydrophobic” constituents in my material besides starch, so I may give it a whirl. I'll try the chloroform-water liquid-liquid extraction and see if the water phase yields any actives as it wouldn't if the chloroform is a much better solvent (at least not much beyond neglibible), especially if I use a 2:1 ratio. Let me ask you this, would an alkaline or salt substance (the aforementioned Ammonium hydroxide and Sodium bisulfite) interfere cause I’ve read a patent where both were used to remove starch from corn. However, if the Ammonium hydroxide is alright but the Sodium bisulfite aint then the the latter could be ommited (allegedly). A link to a more detailed description of this process is:
 
http://www.freepatentsonline.com/y2010/0016576.html

...this patent, I believe, only covers the extraction of starch from corn. Even if this aint true, the patent expired. I called the USPTO to check if the use of said process with other material is legal and was told that the patentee never payed the first maintenance fee so the use prior to a very unlikely readmittance is completely legal and will continue to be thereafter.
 
Maybe I could do as you suggested then flush with a solution of water-Ammonium hydroxide-Sodium bisulfite(if interference is minimal) prior to eluting with Methanol. I’m thinking I might need to save the Ammonium hydroxide-Sodium bisulfite till after the Diaion HP-20 resin wash. What you think?