Normal Phase Vitamin System

[rkh]

I am working with a Normal Phase Vitamin System where I cannot find the peaks... well I see the peak sometimes, and sometimes they are rather blobish. no two injections seem to be the same. CH2Cl2:Hexane Mobile Phase, Std/Spl are in Hexane.Any Advise? Any suggestions on optimun column heater temp, injector rinse?

[tom jupille]

Hmmm

One possibility is late eluters from a previous injection. Another is injector problems (cavitation, air bubbles, etc.).

If it's the former, try letting the separation run for a while longer and see what comes out. If the latter, check the temperature of your samples, look for any obstructions in the syringe, transfer line, etc.

Otherwise, I'm as puzzled as you are.