Can I inject DMSO into HPLC directly?

[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!

[moonchips]

what about ether. Will ether distroy C18 right away?
Or we have to go normal phase in this case?

[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

[Bryan Evans]

For RP, you can look at THF or ethyl acetate. DMSO comes out in the
solvent front as large peak.

[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...

[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?

[tom jupille]

will 5 uL injection of THF hurt the RP C18 badly?

No. In fact, it should not hurt it at all.

[moonchips]

Thanks a lot every one.

[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

[HW Mueller]

How is there a safety issue with 5µL of THF??

[grzesiek]

talked about using it as eluent
formation of peroxides is common thing

[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.