ICS 2000 conductivity fluctuations

[jfcooke]

I’m having a problem with my ICS2000 system. When not running samples, I have the system turned down to a flow of 0.5ml/min, 10mM and 13mA. I turned it down to this on Friday afternoon for the weekend and left it that way all day yesterday. Then about 3:30 I noticed that the mS had spiked up to about 90. I wasn’t real sure what was going on so I turned up the system to normal operating parameters of 1.0ml/min, 32mM and 75mA then ran an eluent blank. The psi was 1690 and the eluent life is at 91%. It seemed to come back down so I turned it back down to the low flow rate overnight. I came in this morning and the detector was at about 200uS and kept fluctuating! It would go down to about 175 then back up to 190, then down to 170, and up to 205, etc. I see no leaks anywhere in the front panel or eluent. I did see a bunch of bubbles in the eluent bottle (EGC III KOH). I disconnected it and inspected the filter, which still looked fine. I hooked everything back up. The mS were about about 140 and did drop down to about 7mS but then started going back up again. Also, the pressure is only at about 1370 psi now. I primed the pump for several minutes and its still doing the same thing. Any ideas???

Jennifer Cooke
Chemistry and Materials Center
1724 Mt. Athos Road
Lynchburg, VA 24504

[mattmullaney]

Hi JFCooke,

Do you have a new, spare un-expired suppressor that you may try out, or the time to take to regenerate the one you've been trying? I would begin here.

The differences in backpressure are troubling to me...perhaps first see if the suppressor swap-out or treatment works. If it does, then you may be "done," if not, swap-out or clean out the column next...depending on what happens with the suppressor.

Please, see what you think, and thank you.

[jfcooke]

Thank you for the reply. After bypassing different parts of the system to isolate the problem, it appears as though my CRD has gone bad.

Jennifer

[mattmullaney]

Hi Jennifer,

Very glad to hear that you cleared up the trouble...I'll admit that I forgot about the CRD, but it's just another suppressor, so-to-speak.

My thanks to you for reading!