Most chemists I meet utilizing flash chromatography use linear gradients. These gradients are either very generic (X% to Y% over a certain time or volume) or can be complex with multiple slope changes and even isocratic holds. These complex gradients are often created during a purification to get the desired separation because the generic gradient does not provide enough separation for the target compound needing purification.
Gradient or isocratic elution, that is the question. Within flash chromatography these are the options afforded to separate reaction mixtures and natural product extracts and is the focus of this post.