Despite recent developments in hyphenated techniques and column technology, analysis of small polar analytes (small organic acids, phosphorylated sugars, and underivatized amino acids) remains challenging. These small charged metabolites are rarely retained on standard reverse phase columns and usually require HILIC/Hypercarb columns or ion chromatography. In ion chromatography run times are usually long, Hypercarb columns usually need extensive conditioning before samples are run and to maintain peak shape HILIC chromatography often requires that extracts contains organic solvents such as acetonitrile which may not be the best solvent for highly polar compounds. All of these techniques require different mobile phases or columns when you move between positive and negatively charged metabolites.
In this webinar presentation, we present an alternative workflow, called CESI-MS, which not only overcomes these stationary-phase-based separation challenges, but is also capable of detecting these polar metabolites at physiological levels without the need for derivatization. We will show how this technique can also be used to separate isobaric and structurally similar metabolites including phosphorylated sugars.
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