More often than not and as a peptide chemist, I am asking myself in which solvent should I dissolve my peptide prior to purification by flash chromatography. I have rarely considered an alternative to the standard liquid injection. However, dry loading is a common technique used by organic chemists prior to their normal-phase purification efforts, especially if the compound isn’t particularly soluble in the mobile phase solvents. To the best of my knowledge, dry loading is not commonly used for peptide purifications.
Immediately, questions come to mind as I attempt this new loading technique. Will my peak shape change if load additional material? Does the stationary phase need to be equilibrated before use? What solvent should I use to load my crude sample? How will my sample recovery be affected? I will address a few of these questions in today’s discussion.