Ethanol peak in headspace runs

[FJ Ram]

Hi everyone, i've been having a problem in my residual solvents runs with headspace. I get a small height-variable peak at 3.4 min in every run, except in the blank, in which i drop solvent directly from the bottle to the vial. I've runned ethanol standards and they elute at that exact time, so i'm almost sure it's an ethanol ghost peak, how can i eliminate it? Can you help me?

[AaronAIT]

Are you using any solvents that contain EtOH as a stabiliser?

[FJ Ram]

I don't think so, i'm using merck's dimethyl sulfoxide (and honeywell).

[kubowicz.tomasz]

Hello

I'd recommend:
1.Run blank (empty, capped vial)
2.Run your std (lowest concentration)
3.Run blank again (empty, capped vial)

If you have no peaks for blanks it means that your problem is not related to hardware. You should try different solvent or check all steps for sample preparation (pipettes, volumetric flask etc)

Regards

Tomasz Kubowicz

[FJ Ram]

Thank you thomasz! I'll run that tests on weekend!

Also, do you think i need glass labware exclusively to GC, restricted from HPLC analysis? And what's the best way i can wash it?

[KM-USA]

Also, do you think i need glass labware exclusively to GC, restricted from HPLC analysis? And what's the best way i can wash it?

No, don't think you need dedicated glassware. Be sure to dry completely though, make sure no condensate remains in volumetric flask necks.