Chromatography Forum

Hello all,

Does anyone of you has experiences with clogged Valco CHEMINERT (4 nl) injector? Is there any solvent which "eat" all the clogged stuff and do not "touch" the CHEMINERT stator? I was working mainly with uracil and alkybenzenes in reversed-phase mode.

Thanks in advance

If it's not too badly clogged, you can try running the flow through the valve in reverse (connect the pump where the column used to be). For uracil & alkylbenzenes, any reasonable mobile phase should work (the trick is to use the pump pressure to blow the plug out the short way).

Thanks Tom, I have already tried it, but probably with the lower pressure than necessary. I had small success with the ultrasonication overnight in (ehm) DMSO, so maybe the combination of both will help. Thanks.

Combining pressure with ultrasound should do the trick.

Peter

I am not familiar with the Valco, but they used to be similar to Rheodyne. If this is the case it should be worthwhile to relate my experience with the Rheodyne: I only recall clogging of the type where some particles (most likely introduced via the syringe) plugged outgoing capillaries (very small inner diameter). Opening one connection after the other revealed which was the culprit (the capillaries with flow to the valve were usually not involved).

Thanks all. It seems, injector is working properly.

Thanks all. It seems, injector is working properly.

So, what was the "magic trick" ?

Thanks all. It seems, injector is working properly.

So, what was the "magic trick" ?

I think the combination of ultrasonic bath and DMSO. However, I still cant "see" through the injection port, eventhough it is injecting.