Chromatography Forum

Hi all,

We run a bunch of agilent uECD and one in particular is acting up. It is giving a signal that oscillates up and down quickly, when zoomed in and doing the math it's about 4.8hz frequency. Looks like electronic spikes with sharp points. When viewing the whole chromatogram the baseline just looks like a fat black line.

I suspect it's something in the detector and not flow. I don't think flow fluctuations would present itself with such sharp peaks so quickly. Trying to find an answer online and hitting a wall. Any suggestions would be helpful. Thank you.

Hello Christian:

You may have a leak. Have you checked to see if your column nut and/ or make up nut are tight? Also, you can take the column out of the detector and use a blank nut to close the detector and then check your baseline. If the problem goes away, then you know your detector is clean; if not, you can increase the detector temperature by about 20 degrees for an hour and then check it again.

Good luck!