Easy question about USP tailing

[Mike H.]

I've noticed that in a method I made, the tailing of the main peak is affected slightly by column temp. 40° T=1.1, 25° it's 0.84. I'm aware that column temp affects selectivity, but why is it also affected tailing? I thought tailing was mostly a function of pH. ty

[HPLC chemist]

Your forgetting the other reaction! This is the interaction between the column and your target molecule, that is the chromatographic separation. This reaction is more efficient at a higher temperature (up to a point). Thus you would see a sharper peak.

[tom jupille]

if TF is < 1, the peak is not "tailing", it's actually "fronting". One possible cause of fronting is limited solubility in the mobile phase; another is a tendency of analyte molecules to form aggregates. Both are less problematic as temperature increases. You can speculate about the specifics, but the bottom line is that temperature can and does impact peak shape.