bunnahabhain wrote:
Along with each column comes usually a certificate. Use the conditions described on the certificate to reproduce the chromatogram of the manufacturer. Do this on arrival of the new column in your lab, and each time you use the column for a new project. If you see that the retention times and peak shapes are comparable to the first use, continue using the column. If not, try to clean it or buy a new one.
I agree to Consumer Products Guy: It is always good to have a spare column in the drawer, at least for columns used in critical projects.
That's what I do. The certificate shows how the column behaves at 23 mM and I run at 23 mM. I noticed sulfate and nitrate were way too close a few months back. We called a thermo guy and he said it was because the pump motor was failing. It had been making clicking noises for a while. Once he replaced that it gave results similar to what the certificate said. I order a spare column after the new one is a few months old. They usually last a year but the last one crapped out in 3 months. The new one took a while to break in too. Fluoride especially changed response after a couple of weeks.