I have a drug molecule and am trying to study the degradation kinetics of it. Based on the chemical structure can we determine how to select an appropriate column? Could someone direct me in the right direction?

One school of thought is that there's little to be gained by trying to get too detailed with column selection. Column chemistry is only *one* of the variables that affect selectivity, and in many respects it is the most difficult to change. This is especially true because it is the only one of the common variables which is fundamentally *discontinuous* (e.g., if one column separates A / B, but not C / D, while another column separates C / D, but not A / B, there is no easy way to obtain intermediate selectivity; if I have similar selectivity change with temperature, or %organic, etc., I can easily work at intermediate conditions).

What this suggests is that you are better off starting with a good, stable, alkyl bonded phase column (C18 or C8) made from high-purity silica. Use the other variables (%B, solvent type, pH, buffer concentration, etc.) to adjust selectivity as necessary. Switch to a different column type if those variables fail.

Other people may disagree!

-- Tom Jupille