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| free radical |
 Posted: Wed Jun 11, 2008 7:27 pm Post subject: Trace butanol in aqueous phase |
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Forum Masters Degree
Joined: 24 Sep 2007
Posts: 503
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I have a technical question.
Exposing an aqueous solution to an organic compound (that is, adding the organic compound - such as butanol - and vortexing) results in some trace of the organic - butanol - entering the aqueous phase, is this correct?
Is there a chemical way to remove the trace butanol from the aqueous phase. For example, would a subsequent vortex with chloroform drive the butanol out?
Hoping this question makes sense -
FR |
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| Bunbury |
| Posted: Wed Jun 11, 2008 7:46 pm Post subject: |
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Forum Ph.D.
Joined: 26 Sep 2007
Posts: 773
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| Could you use activated carbon as an adsorbent for the butanol? |
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| free radical |
| Posted: Wed Jun 11, 2008 8:08 pm Post subject: |
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Forum Masters Degree
Joined: 24 Sep 2007
Posts: 503
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| There is also DNA in the aqueous phase, and I don't want to lose that..... |
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| SteveF |
| Posted: Wed Jun 11, 2008 8:23 pm Post subject: |
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Forum Bachelors Degree
Joined: 28 May 2007
Posts: 466
Location: NC USA
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Â
As near as I can tell, you have used an organic liquid in an extraction technique, leaving a desired product (DNA) in solution in the aqueous phase. After separating the layers you wish to remove traces of the organic liquid, in this case butanol, from the aqueous layer. I hope I have it right.
You have to be careful about trying to remove traces of the butanol. Charcoal adsorption or further extraction with another solvent may remove some DNA.
In some cases you can ignore traces of butanol. If your next step were crystallization or lyophilization, the presence of butanol makes no difference.
If the butanol is really disturbing to your process, perhaps you should have used a different solvent for your extraction. Depending on the previous and succeeding steps, maybe n-hexanol or petroleum ether would have been more suitable.
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| Bunbury |
| Posted: Wed Jun 11, 2008 9:06 pm Post subject: |
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Forum Ph.D.
Joined: 26 Sep 2007
Posts: 773
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| Butanol is somewhat soluble in water. Wouldn't this mean you have more than a trace amount in the water phase? |
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| free radical |
| Posted: Thu Jun 12, 2008 5:06 am Post subject: |
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Forum Masters Degree
Joined: 24 Sep 2007
Posts: 503
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| Yes, the butanol is interfering downstream in the protocol, but evidently phenol and chloroform wouldn't. Would these compounds drive the butanol out of the aqueous phase? |
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| SteveF |
| Posted: Thu Jun 12, 2008 5:25 am Post subject: |
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Forum Bachelors Degree
Joined: 28 May 2007
Posts: 466
Location: NC USA
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Â
Yes, you have the right idea. You will take separate samples of water with dissolved butanol and extract with various solvents. Examine each result to see if any butanol remains in the aqueous phase. Check that there is no longer any butanol interference with the succeeding steps in your main protocol.
Be patient and take good notes.
This is what a scientist does.
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| free radical |
| Posted: Thu Jun 12, 2008 1:27 pm Post subject: |
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Forum Masters Degree
Joined: 24 Sep 2007
Posts: 503
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| SteveF wrote: |
Â
Yes, you have the right idea. You will take separate samples of water with dissolved butanol and extract with various solvents. Examine each result to see if any butanol remains in the aqueous phase. Check that there is no longer any butanol interference with the succeeding steps in your main protocol.
Be patient and take good notes.
This is what a scientist does.
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Bloody hell, mate. Whatever scientists 'do,' one thing we do not do is reinvent the wheel.
Your first line suggests that organics generallly replace other organics in aqueous phase. Thanks for that. |
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