Dionex ICS-90 Issues

Discussions about IC and related topics

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I am running a cs12a column and cmms suppressor. The eluent is 20mM MSA and the 100 mM regenerant is TBAOH for cations. The machine was running perfectly until it was shut down for about two weeks. Now the conductivity reading is maxed out and baseline is flat with no response. I have changed suppressor, column, remade eluent and regenerant but it will not go back down. If I run DI water through the system it comes down but the moment I hook back up the MSA eluent it goes right back up. Seems like a suppressor issue but I have tried two different suppressor with the same thing happening. If I do an off line regeneration, the machine works properly for about ten minutes then it goes back to the same problem. Anyone have any sugestions or ideas of what the problem might be? Thanks......................... Also how to properly make the TBAOH regenerant using FLuka 40% in water. Dionex only shows preparation using there material.
Definitely sounds like a suppressor problem. Did you remember to turn the suppressor on??

As for your question about TBAOH regenerant - easy chemistry 101:
40% TBAOH = 1.5M (from Sigma's product page)
You need 100mM or 0.100M
(1.5M)(x)=(0.100M)(1L)
x=66.6mL in 1L
Problem Solved. It Was An Issue With The Regenerant Not Completely Regenerating The Suppressor. The Regenerant Reservoir Needed To Have A Head Pressure To Increase The Flow Rate(Which It Says Nothing About in The Manual) And The Regenerant Either Went Bad Or Wasn't Made Properly.Thank You That Is Exactly The Way I Made It 67ml/L For 100 mM Or .1M.
Hello redrider8606,

Could you please advise how did you manage to resolve the issue?
I have the same issue with the same unit. I have tried with lower eluent conc (from 20 to 5mM MSA with 100mM TBAOH). I have managed to lower the conductivity (from 590 to 2uS/cm), but now I cannot detect Ca and Mg (because of weak eluent I don't see low concentrations (below 10ppm)). I have regenerated suppressor with NaOH, and still got nothing different...
When I use higher conc of MSA I get much higher conductivity and I cannot see the peaks of K, Na etc...
Could you please clarify the "Head Pressure To Increase The Flow Rate" you've mentioned? How did you do that?

Thanks!
The suppressor caused this problem. It was necessary to replace suppressor and always use a fresh solution.
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