GoldGuy - 18-2-2014 at 15:17
It has long been known that the addition of an inorganic salt into a mixture of water and a water-miscible organic solvent causes a separation of the
solvent from the mixture and the formation of a two-phase system.
Observations of this "salting-out" phenomenon were made for a number of water-miscible organics such as acetone, methanol, and ethanol.
This salting out often occurs at high salt concentrations. In some cases, the "salting-out" (or perhaps better termed "sugaring out") effect also can
be achieved with high concentrations of saccharides.
Any knowledge or experience out there of using a water miscible solvent such as, acetone, methanol, or ethanol to do SALLE?
It seems advantageous to conventional extraction for many reasons:
1. Methanol is about 1/10 of the price of ether where I am
2. Ether/Toulene is hard to intimately mix with water and extremely labor intensive
3. I extract from a fermentation broth and since ethanol is produced as a by product is only makes sense to extract with an alcohol aswell
4. If one could use sucrose for the "sugaring-out" of a fermentation broth, the sugar can be theoretically re-used
Any information as to the salt/sugar concentrations? Or any other pertentent information on this technique for the home scientist would be appreciated
[I copied most of my words from
http://www.chromatographyonline.com/lcgc/Column%3A+Sample+Prep+Perspectives/Salting-out-Liquid-Liquid-Extraction-SALLE/ArticleStandard/Article/detail/
613590]
[Edited on 18-2-2014 by GoldGuy]
[Edited on 19-2-2014 by GoldGuy]
Brain&Force - 18-2-2014 at 20:07
The best alcohol to use for salting out is the commonly available isopropanol. Methanol and ethanol tend to precipitate the salt in the water
instead, see this thread: http://www.sciencemadness.org/talk/viewthread.php?tid=28399
GoldGuy - 20-2-2014 at 08:46
Acetone, ethanol, methanol, are all soluble in sugar.
I out of all I've read it seems that K2CO3 is the best.. but still not suitable for all because it makes a very basic solution.
Use K2CO3 and keep my solution acidic? How?
Im thinking acetone as solvent and MgSO4 (Epsom salt) as the salt. MgSO4 is insoluble in acetone.
Side note: Isopropyl seems to be least soluble in salt solutions and sugar solutions... high bp though