Chromatography Forum

New to the forum, glad to be here.

Looking for any help with an eclipse 4660 purge-and-trap concentrator for water purge.
A handfull of volatile compounds are low recovery < 50% and seems to be getting worse. (they are heavier compounds including naphthalene).
The purge gas flow is very low, but it will not adjust higher with the purge gas knob.
Could there be a blockage some where?
Or?
Any advise would be appriciated.

What changes have you made before the low purge flow problem? It should be constant at around 40 ml/min. Check for leaks, not blockage.

Just running samples and noticed some compounds in OC samples getting lower. Compensated once with a calibration and was good for about three days until the compounds became to low again.
Well, at first i started checking for leaks and found some @ the trap and also changed the sparge.
So now no leaks, but still no flow while purging @ 6.0 ml/min at purge vent. Regulator knob has no effect.
I checked at the sparge and He flow is 42 ml/min.
Anyway, I "rinsed the sample pathway" with MeOH both with & without the transfer line, baked out the system.
AND it looks better now (purge flow @ vent 34 ml/min) regulator knob may have a problem. Still need to calibrate though.
The jury is still out, but for now I'm a happy camper.

Just an update, thank you.

Doctor Purge,

What method are you running with your 4660?