Re: ORGLIST: brine/water washing

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From: Dr. S. K. Adhikari (sisir_ad$##$vsnl.com)
Date: Fri Nov 28 2008 - 09:38:27 EST


Hi all,
Frankly the "work up" requires a brine wash first to eliminate the
possibility of forming of an emulsion [ in many cases one looses product
due to this ]. Brine wash also gives a density edge too in separation of
layers . Now one can wash with water to remove all aqueous soluble
,[followed by acid or alkali if needed in cases] ,followed by water to make
neutral , dry via desired Sodium /magnesium sulphate and distill . These
are standard & the path is short or long depending on products or right
observations.
S.K.Adhikari
----- Original Message -----
From: "Jaosn Smith" <jason.smith1$##$students.mq.edu.au>
To: <everybody$##$orglist.net>
Sent: Friday, November 28, 2008 2:42 PM
Subject: Re: ORGLIST: brine/water washing

In my experience, I would wash with water to extract water soluble
impurities, followed by brine to extract left over water from organic
solvent, followed by drying product and organic solvent with anhydrous
MgSO4. It would certainly be odd to be using water after brine in this
instance, if this is what you meant.

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From: everybody-bounces$##$orglist.net [mailto:everybody-bounces$##$orglist.net]
On Behalf Of Ohad Ilovich
Sent: Thursday, 27 November 2008 9:10 PM
To: everybody$##$orglist.net
Subject: ORGLIST: brine/water washing

Dear all,
I have a rather strange question. I've seen in a couple of articles where
someone extracted his compound in some organic solvent and than washed the
organic phase in both brine and water.
As i understand it brine is used when the organic solvent is miscible with
water and the salting out effect of the brine inhibits the compound
dissolved in the organic phase from passing to the brine. water is used
pretty much of all other solvents.
The only idea why brine AND water will be used is to maybe get rid of any
NaCl leftover which may have passed to the organic phase.
Am i mistaken or is this double washing just a waste of time?

-- 
Ohad Ilovich, M.Sc, B.Pharm
Cyclotron/Radiochemistry Unit
Nuclear Medicine Department
Hadassah/Hebrew University Hospital
Jerusalem 91120, Israel
Fax : 972 2 6412033
Tel: 972 2 6777197

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