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Can I inject DMSO into HPLC directly?
Posted: Thu Jul 23, 2009 6:06 pm
by moonchips
We are doing screening of solubility of our API in various solvent.
some solvents we would like to try are oil, lipid etc. They are completely inmiscible in methanol, ACN.
Can we use DMSO and inject DMSO directly onto HPLC. What is the risk of doing it?
If we prepare API std in methanol, but use DMSO for sample prep, what risk do we have?
Thank you very much!
Posted: Thu Jul 23, 2009 6:38 pm
by moonchips
what about ether. Will ether distroy C18 right away?
Or we have to go normal phase in this case?
Posted: Thu Jul 23, 2009 6:44 pm
by Bryan Evans
Seeing as your solvents are not miscible with MeOH or ACN, you
probably need to evaluate normal phase.
So here is DMS0 on Unison UK-Silica:
http://www.imtaktusa.com/site_media/fil ... TI209E.pdf
Posted: Thu Jul 23, 2009 6:53 pm
by Bryan Evans
For RP, you can look at THF or ethyl acetate. DMSO comes out in the
solvent front as large peak.
Posted: Fri Jul 24, 2009 10:51 am
by lmh
it would be really nice if you were able to obtain your analyte in radiolabelled form; then you could just mix it with the oily stuff, separate the phases, and count the label...
Posted: Fri Jul 24, 2009 2:43 pm
by moonchips
Thank you guys. Very useful imput.
it turned out THF can dissolve all my oil, lipid etc.
will 5 uL injection of THF hurt the RP C18 badly?
Posted: Fri Jul 24, 2009 6:17 pm
by tom jupille
will 5 uL injection of THF hurt the RP C18 badly?
No. In fact, it should not hurt it at all.
Posted: Fri Jul 24, 2009 7:28 pm
by moonchips
Thanks a lot every one.
Posted: Thu Jul 30, 2009 1:35 pm
by grzesiek
THF is a solvent for RPHPLC but it's not used so much anymore, this has nothing to do with it's chromatografic properties, rather safety
Posted: Sun Aug 02, 2009 10:29 am
by HW Mueller
How is there a safety issue with 5µL of THF??
Posted: Sun Aug 02, 2009 11:06 am
by grzesiek
talked about using it as eluent
formation of peroxides is common thing
Posted: Mon Aug 03, 2009 9:02 am
by lmh
you can still use it. It's recommended for Thermo's hypercarb column. But it's a good idea to respect use-by dates and keep turning it over.