Contamination in GC

[danycuri]

Hello everyone,

Please, i need some help about a contamination peak.
I'm very new in the GC world, but i clean de ion source, change the liner, clean the injector and i can't eliminate de contamination.

If the inyection is hexane-solvent, the contamination appears, but if i inyect ethanol-solvent not appears.

Maybe someone can recognize the fragments:
-149
-177
or asociate to some lab-trouble or something else.

thanks for the space!!
And sorry for my english level :/

[la_donz27]

If the Hexane injection has the contamination but the ethanol injection does not, try using a fresh batch of hexane. Also, did you try cleaning your syringe as well? That might help.

[danycuri]

Thanks for the advice, but also try this things and the contaminant still there.
I read too, wrap the septa with aluminium foil, but i dont try this yet.

Any other advice , I will be grateful

Thanks!

[Yama001]

149 and 177 sound like a phthalate ester - likely diethyl phthalate. Easily extracted off of gloves and other plastic stuff. Possibly in the hexane to start with. Ethanol would also not leach as much phthalate from lab ware.

[AICMM]

Phthalate. Nothing plastic anywhere in the process. All glass.

Start with a fresh bottle of hexane, then set up injection using all rinsed glass sampling train.

Best regards,

AICMM

[whdees]

you might want to try soaking your septa in hexane until they swell up, say several hours, then rinse them with fresh hexane, and let them dry out and shrink back to normal size. I have found this helpful in the past.

[Bigbear]

Some of the green septa I've used contained quite a bit of phthalates. I swapper to Agilent BTO's.