Chromatography Forum

Afternoon all!

I am looking to reduce the run time on a GPC method and have stumbled across the potential of using temperatures above the boiling point of the eluent.

Has anybody had any experience with this technique? there is a paper that i am trying to source but that is likely to take a while to process so i thought i'd ask on here.

Thanks for any advice/ info that you can offer

Steve

As long as this works with the detector choices that you have, I do not see anything wrong with it. I also do not necessarily see a benefit. The common reason for doing GPC at elevated temperatures is the sample solubility, and there your approach wouldn't help.

but surely the temperature of the system will have an impact on the retion time of analytes? i have seen similar data when samples were run on 30C conditions and then repeated at 40 and 50C and the retion times do shorten.

i'm fairly confident about this but it was the use of solvents above their boiling point that concerned me.

yours views on the subject Uwe Neue are appreciated nevertheless.

Thanks

Steve

GPC or size exclusion chromatography is a separation based on the size of the molecules, and not on interaction with the stationary phase. If the polymer is dissolved well, its retention pattern does not change. If it does, it is not GPC, and you have a secondary mechanism going on, which is bad news for a GPC application. Alternatively, you may just look at solvent expansion if your solvent heater is behind the pump. This reduces retention times but does not change the chromatography.