Discussion Category: Ion Chromatography
High and Variable Conductivity Signals
Recently our ICS-3000 ran without DI water eluent A while running cations. For several hours 100mM NaOH was pumped through the system as pure eluent B. We are currently having problems with variable and high conductivity signal readings when we run the machine without samples. Typically the signal stays close to 0uS for 1.5-2 hours before increasing to values ranging from values between 500uS-7000uS at which point it more or less plateaus. Turning off the IC and restarting it brings the conductivity value back to approximately 0uS.
What issues could have been caused by running the machine without DI water, and what potential protocols could we look to for troubleshooting?
We often get a Degasser Malfunction (yellow triangle with exclamation point) warning that does not seem to have an effect on elevated signals.
Please contact me at almariet.palm@gmail.com or 203-535-6845. Thank you
Reply byWe had a similar problem several years ago and according to my notes it was due to air bubbles trapped in the conductivity cell; probably due to installing a different column. If you’re lucky, this could be solved by loosening and then retightening the lines to and from the conductivity cell and suppressor eluent ports. I think we actually went as far as flushing the cell and suppressor with fittings connected to a syringe containing degassed HPLC water. I'm not sure if the degasser malfunction you have could be introducing air into the system. Hope this helps.