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ICS-3000 Ion Chromatography bubbles
Posted: Thu Jan 15, 2015 7:40 am
by Amaya
Hello,
I'm new to IC but the system seem to have a constant problems with bubbles that seem to worsen lately. We use the IC to test water samples only (6 anions and by products). The eluent is refilled on a daily bases but this cause bubbles to form, we prime the pump. This causes the peaks of samples to shift from the calibration peaks (retention time changes), we run the standards again to re-do the calibration. We have to re-do the calibration 3-4 time a month (only this January we did it 3 times so far). Is this normal?
Re: ICS-3000 Ion Chromatography bubbles
Posted: Thu Jan 15, 2015 8:23 am
by Gerhard Kratz
How do you degass your mobile phase???????
Re: ICS-3000 Ion Chromatography bubbles
Posted: Thu Jan 15, 2015 8:26 am
by kubowicz.tomasz
Hello
I'd check:
-mobile phase filter (replace or clean) - air bubble can be from filter
-degasser connections - check if all are tight enough (air can be sucked in there)
Regards
Tomasz Kubowicz
Re: ICS-3000 Ion Chromatography bubbles
Posted: Thu Jan 15, 2015 10:12 am
by Amaya
They used to use N2 for degassing, but stopped it recently.
Also, the stopped using the filter because it was causing even more bubbles.
Can the priming cause the retention time to change?
Re: ICS-3000 Ion Chromatography bubbles
Posted: Thu Jan 15, 2015 10:28 am
by Gerhard Kratz
Air bubbles in the mobile phase, pump can influence RT. can you ultrasonic your mobile phase when you start in the morning?
Re: ICS-3000 Ion Chromatography bubbles
Posted: Fri Jan 16, 2015 12:14 am
by tom jupille
They used to use N2 for degassing, but stopped it recently.
You're joking right? Air is 80% N2, so bubbling N2 through the mobile phase is the exact opposite of what you need (no wonder you had bubble problems!). Degassing can be done with helium, because He is almost insoluble.
Re: ICS-3000 Ion Chromatography bubbles
Posted: Fri Jan 16, 2015 2:16 am
by mattmullaney
Back in the days of old with the Dionex DX-400, we boiled the conductivity water and allowed it to cool under Ascarite before making IC eluents...that was obviously QUITE a while ago. Did a good job with the retention times of analytes (though it was a true bother), not so good with background conductivity, but then I wasn't doing a whole lot of trace-level work.
He is an excellent sparging gas...when I was asked to try nitrogen for HPLC work, I found that the pumps "choked" pretty often...my question here is, is sonication of the water in conjunction with applied vacuum a possibility...prior to putting the degassed water into a bottle to feed the eluent generator?
My thanks.