Peak fronting in NP chiral chromatography

[Mike H.]

I've noticed that my peaks front at 40°, but are symmetrical at 30°. This is a NP isocratic method 80:20:0.1 Heptane:EtOH:DEA. The causes of fronting that I'm aware of are sample overload, solvent mismatch, low solubility of sample in MP, but I never read that temp was a cause. Can somebody explain the mechanism? thx

[Rndirk]

What kind of compounds are you analyzing? Do they all show the same effect?

Is it possible that the compounds show isomerization at elevated temperatures?