redbaron
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Sand instead of silica in chromatography?
For those who can't afford commercial chromatography silica, what about using lab-grade sand as an adsorbent instead? Could it work?
[Edited on 30-6-2007 by redbaron]
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solo
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I assume you're talking about columm chromatography, because for TLC it just wouldn't work........ I don't see why not as log as you can sieve it to a
fine powder.........solo
It's better to die on your feet, than live on your knees....Emiliano Zapata.
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matei
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It won't work because sand grains are not porous. Adsorbents used in chromatography have a very high surface area.
As an alternative to commercial chromatography-grade silica I think you might use regular silica gel (used e.g. for drying, which is cheap) if you
grind it to a very fine powder and sieve it, as solo suggested.
[Edited on 30-6-2007 by matei]
[Edited on 30-6-2007 by matei]
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redbaron
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| Quote: | Originally posted by matei
It won't work because sand grains are not porous. Adsorbents used in chromatography have a very high surface area.
As an alternative to commercial chromatography-grade silica I think you might use regular silica gel (used e.g. for drying, which is cheap) if you
grind it to a very fine powder and sieve it, as solo suggested.
[Edited on 30-6-2007 by matei]
[Edited on 30-6-2007 by matei] |
I had a feeling there was some reason it wasn't used. That's a great idea, thanks for the input.
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Pyridinium
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Could use diatomaceous earth... much higher surface area than sand.
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BromicAcid
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I remember reading a paper discussing some of the early chromatography mediums and it was surprising the number of different compounds, most of which
were readily availble, that they used. For instance, I specifically remember calcium carbonate as one chromatography medium, and I think sodium
chloride too. The stipulation is that they be very very finely pulverized. Just remember that these different mediums will affect the polarity of
the column so if you are using literature as a guide then things will likely not turn out as you expect.
[Edited on 6/30/2007 by BromicAcid]
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solo
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In my part of the woods there are many kaolinite mining, the material is a rock like form but can be converted to a fine dust ......see Wikipedia
http://en.wikipedia.org/wiki/Kaolinite
I guess it can be pulverized and used also as a chromatography material ......I will give it a try ....also lots of diatomaceous earth around
here....should count my blessings.....solo
It's better to die on your feet, than live on your knees....Emiliano Zapata.
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12AX7
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I have a 50 pound sack of KT#1-4 ball clay, which is rated as 11.0 meq/100g CEC.
http://ceramic-materials.com/cermat/material/943.html
I've been thinking of setting up a column and trying some ion exchange, but I don't really know what I would use it for. It would also percolate
extraordinarily slowly!
Tim
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not_important
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Tsvet, who founded and named chromatography, used chalk in his columns, confectioners sugar has also been used with non-aqueous mobile phases.
Clays work when dry, again with non-aqueous solvents. There's been some research done using water, modeling natural systems; the problem is that it's
hard to come by grad students willing to spend a few hundred years running a separation.
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Del Rocco
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What about cab-o-sil, which is highly porous fumed silica?
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12AX7
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So clay binds aqueous phases rather strongly?
Besides being rather slow already, of course. Clay can be mixed with sand and whatnot to loosen it. You might go outside and pick up a sample of
local loam to do the same thing.
Tim
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Pyridinium
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found a patent online for extracting lysozyme from egg white; the adsorbent is diatomaceous earth, clay, and / or zeolite. Looks like a nice
mad-science experiment- all materials are readily obtainable. The lysozyme can be eluted with NaCl solution.
http://www.freepatentsonline.com/7060478.html
They noted that bentonite wasn't very specific at binding lysozyme, but that doesn't mean it won't be good for some other compound.
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guy
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So diatomaceous can work fairly well?
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not_important
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| Quote: | Originally posted by guy
So diatomaceous can work fairly well? |
Yes, it has high surface area. Often it has various treatments done to it, such as acid washing, before it is used. It's more commonly used in
pre-treatment columns, or as the support for gas chromatography.
examples
http://www.sciencedirect.com/science?_ob=ArticleURL&_udi...
http://www.jgp.org/cgi/content/abstract/38/6/743
http://www3.interscience.wiley.com/cgi-bin/abstract/11334000...
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