acidic and basic analytes...which column?
<p>Trying to develop UPLC-MS (ESI) method for anlaysis of an aminoglycoside (very polar and very basic!) and a glycopeptide (also polar but less basic). I can retain the GP on HSS T3, but not sure where the AG is. Oddly I thought I had it down when using 0.1%FA in H2O with shallow gradient using 0.1%FA in MeOH. Actually saw two peaks so thought I was golden. 30 or so injections later, can't see the AG anymore!?!? Where oh where did it go? I've thought about HILIC and have the Amide column to try but the thought of switching everything out kind of bums me out. Besides not sure what'll happen to the GP. Any thoughts from the better chromatographers than I that I know are out there? Thanks!</p>