From: Paul D. Jones (pdjones$##$ucdavis.edu)
Date: Fri Apr 15 2005 - 13:26:55 EDT
This is a very common problem, especially with solvents such as DMSO, DMF
and HMPA. The trick I use it as follows:
Take a small aliquot of your reaction, say 50 microliters and dissolve it
in a solvent such as ethyl acetate or dichloromethane. then add 250-500
microliters of water. Shake the mixture than use the organic layer and spot
your TLC. This mini extraction usually removes most of the DMSO from you
sample, so the TLC is usually cleaner.
Hope this helps.
Paul D. Jones, Ph.D.
NIH Postdoctoral Fellow
Department of Entomology &
Cancer Research Center
University of California, Davis
Davis, CA 95616
>Are there any "tricks" for developing and visualizing
>spots when DMSO is used as a reaction solvent? DMSO
>just seems to spread out on the plate rather than
>evaporate, even after prolonged heating. As I result I
>often have huge spots that obscure a component or two,
>no matter what solvent system or adsorbent (normal or
>reverse phase) I use. The reaction components are
>usually not UV-active.
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