Chromatography Forum

Hi, there,

I observed stability problem of miconazole in methanol or water, so I am trying to dissolve it in DMSO. I am just wondering if LCMSMS can tolerate small amount of DMSO. Thanks in advance for your reply.

mei

There several reasons I wouldn't inject or infuse a sample in pure DMSO:

(1) It is nonvolatile (b.p. 189°C) so isn't likely to be a good solvent for electrospray ionization.

(2) PEEK tubing is incompatible with DMSO. If it is possible for you to have all stainless-steel tubing between your injector and ion source, this doesn't apply.

(3) I think DMSO would act as a strong solvent in reversed-phase LC, so if you're doing chromatography, you'd get distorted peaks or split peaks.

These problems should be less pronounced with lower percentages of DMSO, but you'd have to experiment.