Column Chromatography

Stinging_Nettle · Mon Sep 26, 2005 4:05 pm

This is fairly common technique in a laboratory. However it is quite tricky really when you think of all the things needed. Flash chromatography is by far the preferred method but not essential.

My question is how many bees have experiented with it outside a lab and what are there results been like.

More specifically my question relates to the grade of silica gel used and the TLC.

Was it possible to use regular silica gel that was dried in an oven? Ie the granular texture and not the powdery stuff that costs a fortune.

Also im worried about how much the TLC plates and capillary tubes will set SWISN back. I know that it is not worth a great amount but that doesnt stop suppliers from tapping a large premium onto it.

Then in the visualization of the TLC plates is it possible to usxe a fluorescent key chain light instead of buying an expensive light box. SWISN just needs to be able to see what he is doing and doesnt necessarily want to have all the bells/whistles attached if he can avoid it.

SWISN also plans on recycling his solvents which was sort frowned upon in a professional laboratory setting. Unfortunately though SWISN does not have a rotary evaporator, he is not that rich!

methyl_ethyl · Riedel De Haen

You would be surprised how easy it is to utilize column chromatography without the need for pumps, and expensive equipment.

Small polyethylene columns are easily available, that can be packed with many different column packing materials that are available in a slurry, which makes things even easier.

Put your mind to it and develop a purification scheme that does not require a gradient, but can utilize a bind and elute scheme. Simply introduce and bind the sample to the properly selected column, wash away the impurities that do not bind to the column packing, then elute the semi purified sample with the appropriate elution buffer, and repeat using a series of columns that sequentially purify your target from known contaminates.

Granted this will take quite a bit of research to decide which column packing will be appropriate for your target, and what buffers will be appropriate to bind, wash, elute, and strip.

I am not sure what you are trying to purify (if in fact you are trying to purify), so perhaps the above suggestion will not work for you. I just don't like TLC for some reason or another.....

Now if purification is not what your after, then I guess this suggestion would not help you. If you are trying to asess the purity of a substance then I guess gravity fed preparative chromatography will be useless to you, with out some means of detection.

for some reason i thought you were trying to purify rather than asess purity.

regards,

m_e

Stinging_Nettle · Wed Sep 28, 2005 1:11 pm

Yes SWIN is making compounds or will be making compounds and due to the nature of the post reaction soup, chromatography is ore or less essential to get pure product. SWIN is trying to get a 96 x test tube holder rack and knows where he can buy cheap test tubes. SWIN already has laboratory experience though and realizes that it is a frustrating technique to use and is not something that can be condoned for an amateur.

Lego · Thu Sep 29, 2005 1:53 am

Stinging_Nettle · Thu Sep 29, 2005 2:05 pm

loki · guinea pig

i don't think you can use regular domestic UV lamps for getting fluorescence, requires the type that they use in medicine and forensics (the type which makes blood traces luminate)

methyl_ethyl · Riedel De Haen

Stinging_Nettle · Sun Oct 02, 2005 7:39 am

I've found a source for TLC plates now so that is another load off my mind. But yeah swin is gonna use a cheap UV torch and hopefully this will be enough to make the fluorescent indicator light up. Well actually swin is planning on doing real research although he will be using literature and patent background to prop-up this up. With the silica gel that is granula he might try adding this to a food blender to get a finer particle size. He will start small but if things go according to plan then he will scale up to make commercial amounts of product.