broad solvent front in GC

[jasiakb]

I have always run a toluene blank with a 500 sec. acquisition delay on the detector. After this delay, I would naturally have no toluene show up as it would have all been gone by then. I ran a sample which contained 200 pg of analyt - and i injected 5 ul. Now since then, I'm getting my solvent peak tailing off for the entire run ! Even after about 500 seconds delay the peak abundance is up to 120,000 units. any suggestions?

[Peter Apps]

Inlet maintenance.

Peter

[chromatographer1]

and / or

column trimming or replacement.

Rodney George

[AICMM]

I would also look at the split valve. If not operating correctly and you are staying splitless you sensitivity would not improve but your solvent peak will go on for the full run.

Best regards.