Glufib (standard) coming off column far too late! Help!

[Euhalojags]

I am using LC Packings Ultimate-Switchos-Famos coupled to Applied Biosystems QStar Mass Spec. I believe it is a typical set-up for most people doing shotgun proteomics.

Unfortuntely, our standard which is Glufib is coming off far too late in a 30 min gradient. The pressures are fine and a colleague has suggested we have dead volume in the system. Could you suggest a way we can sort this problem out and whether it is dead volume issue?

Thanks for your time

Euhalo-Jags

[MIB_EO]

Often also shows in poor peak shape. If you have tailing on the peak then you may well have deadtime. Check all your fittings!

[Euhalojags]

Hi, thanks for the reply. We had to take the valve and all the fittings apart, give them a clean with methanol and then it worked.

many thanks for your help.