Strange Crystalization in an batch of Distillate

[cyclopath]

I’m wandering over here…and need a clue or three.

Method development. How to split co-eluting peaks?

The discussion re:delta 10 vs CBC brought up a problem I’m having setting up an SRI 310MM . It’s got a Hayes sepD packed column, but did not come with a preinstalled “solvent” method. I grabbed samples of all the solvents I had lying around, and ran into a problem: pentane and acetone are co-migrating. I’ve only tried 140C for 12min, 180C for 10min, and a ramp from 140 to 180, but clearly I’m just flailing around with no conceptual framework on how this works. Is there an analytical chemist…