chromatography and radial spread

[pery]

Hi I am an artist and have been creating radial spreads with ink in water (surface tension generated flow) and it was suggested to me that my methods were similar to those of Runge. I have since been wondering if it would be possible to do chromatography with radial spread techniques. I am a complete layman, but have worked out a possible method and if anyone's interested I can run it past them. I would love to know if it's possible!

Many thanks, Pery

[rhaefe]

Pery,

something along those lines?

http://tinyurl.com/2hwacb

cheers

[DR]

You may also want to google Field Flow Fractionation.

[pery]

Thanks for the leads - have now read about these types of chromatography; was not sure how the Field Flow fractionation results are recorded. With the radial spreads, separations would occur in water, and would then be photographed as 3-dimensional events. Perhaps something similar happens in FFF.

[Peter Apps]

Hi Pery

By radial spread do you mean that you put a drop of oil-based ink onto water, and it spreads into a disc ? If so it is radically different from thin layer chromatography.

If you can generate concentric circles of different colours when your ink contains different dyes, then there might be some liquid-liquid chromatography going on, with water as the stationary phase and oil as the mobile phase.

Can you post a picture for us - instructions on inserting files are at the top of the LC page.

Peter

[pery]

[img][img]http://i3.tinypic.com/2dl6r1l.jpg[/img][/img]
Hi Peter,
Thanks for your message. This picture shows some spreads at various stages, starting from blobs of ink on top of gold paint (upper right), all floating on water) starting to expand (lower right), and much bigger (left). I'm using two inks - blue & yellow - here, and it's a 3-dimensional physical, not chemical, process (good for observing diffusion by the way). For chromatography, I thought something like this (sorry don't know the proper terminology): put the substance undergoing chemical separation on a liquid platform (like my gold paint which is a platform). Float it on a chemically reactive liquid substrate (same function as filter paper, say, but with volume). The platform does two jobs: first prevent substance and substrate interacting until the spread begins; second, facilitate radial spread. When the spread begins, substance + substrate meet, resulting in chemical reaction, and therefore separations of the substance. The spread's colour will change as it moves out and down through the substrate.
I am just speculating - don't know what chemicals one could use etc. but thought it might be interesting to try!

Best,

Pery

[Peter Apps]

Hi Pery

If substance and substrate react chemically (effectively irreversibly) then the process is not chromatographic. For chromatography you have to have a reversible interaction of substance and substrate.

In principal you could do chromatography between a spreading oil film and the water that it was floating on, but the practical difficulties would be horrific. If you can find dyes (not pigments) that will dissolve however slightly in both oil and water, mix them into oil and put a drop onto water (no gold paint) concentric coloured rings would probably be due to chromatography.

Good luck

Peter

[pery]

Hi Peter,
Thanks for your reply - I obviously need to do lots of experiments with different dyes. If I come up with something I'll let you know!
Cheers, Pery