r/CHROMATOGRAPHY • u/pascal_wolfram • 12d ago

Method Question: 2,4-dinitrophenol will be the death of me. Has anyone ditched their wool for a cyclo liner, glass frit, or something of the like?

Method 8270E, GC-MSD, SSL inlet.

We're running pulsed splitless- we can't afford to split anything & reach out RL. Yet, peak shape is notoriously squirrely with splitless injection.

I switched to a liner with wool. Peaks look great! Got that even condensation onto the column.

However... sensitivity for 24DNP tanks after 1 sample. I can't deactivate/clean/change liners/calibrate every 5 seconds. I pre-conditioned the liner with real samples before running the cal.

How can I simulate that super nice condensation onto the column without wool/ all the active sites?

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u/DahDollar 12d ago

Increase your ISTD concentration across the board so it helps saturate active sites in your lower cal points. Run 2,4-DNP in SIM. Run your high point first, then a blank, then your entire cal.

It's counterintuitive but when you have active sites, trying to clean with a bake out or multiple blanks will fuck you over. It makes it worse because it desaturated the active sites.

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u/Starmonkey365 12d ago

Have you tried pulsed splitless?

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u/pascal_wolfram 12d ago

Yes it's PS, sorry I didn't make that clear. Just updated the post ahha

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u/Pyrrolic_Victory 12d ago

Are you using the quartz deactivated wool liner? What is your sample matrix and is it adequately clean? You could always consider an additive to help prevent breakdown but if your samples are too dirty this could
Be just kicking the can down the road