morsagh
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Salting out
If i have a solution of benzyl alcohole in water (very low concentration) can i use salt to separate benzyl alcohole (just to identify that bezyl
alcohole really is in solution? Can be used NaOH?
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byko3y
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Use another lipophilic solvent - it's hard to impossible to extract benzyl alcohol from water solution with a bare salt.
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Amos
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Quote: Originally posted by byko3y  | | Use another lipophilic solvent - it's hard to impossible to extract benzyl alcohol from water solution with a bare salt. |
This is based on what?
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byko3y
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This is based on practical observations.
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Amos
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Well, "a salt" refers to a few hundred readily accessible compounds that could potentially be used to separate the benzyl alcohol and water. I've had
great success using anhydrous sodium acetate and chromium(III) sulfate as salting-out agents before, and they work on things that normally would be
impossible with sodium chloride or potassium carbonate. So I wouldn't act as though all attempts at salting out would be fruitless.
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deltaH
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You might try anhydrous K3PO4, it's a pretty powerful salting out reagent. We've shown on another SM thread that it can salt out ethanol from liquor
forming a near 100% alcohol second layer.
The problem with salting out dilute solutions is the volume of the second solution is too small. A workaround may be to add alcohol to the water, say
enough to obtain a 30% solution (ethanol, isopropyl alcohol or even 'rubbing alcohol'), then salt out the alcohol AND benzyl alcohol together using
anhydrous K3PO4, then simply evaporate or distill the alcohol to recover the crude product. This then becomes a combined salting-out and extraction
step and so should be more powerful at recovering dilute product.
[Edited on 27-11-2015 by deltaH]
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