Unexplained Baseline on 5890 II

GCTime 11 days ago

Hello everyone,

We have a 5890 II with a DB-1 column and FID that has an odd baseline behavior. It has a spiky signal that persists even after clipping the column, doing maintenance on the inlet, checking the gases, and heating the pencil filter. It only appears during ramp and does not appear when the temperature is constant. There are also unexplained spikes that happen even when the GC is idling (not currently running a sample). The following are three blanks run in a row.

Any insights would be helpful.

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GloriaApp 10 days ago +1

Hello GCTime , conducting inlet maintenance was an excellent decision. However, it is important to note that the detector frequently influences the baseline output. Factors such as contamination and the…

0 GloriaApp 10 days ago

Hello GCTime , conducting inlet maintenance was an excellent decision. However, it is important to note that the detector frequently influences the baseline output. Factors such as contamination and the purity of the fuel, air, and makeup gases (if applicable) can significantly impact the baseline output. Performing a straightforward FID bakeout and maintenance procedure can likely resolve contamination issues. Enclosed are the steps for FID maintenance. Additionally, we recommend verifying that your gas purity meets Agilent’s standard of 99.9995% or higher

Bake Out the Agilent Flame Ionization Detector - Articles - GC Portal - Agilent Community

How to Clean an FID - Articles - GC Portal - Agilent Community

Troubleshooting FID Noise and High Background - Articles - GC Portal - Agilent Community
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0 GCTime 4 days ago in reply to GloriaApp

Hello, thanks for the answer.

I had cleaned the FID before those runs were performed. I went in with a blind nut and baked out the FID. When I put in the blind nut, I had the signal max out but lifting and replacing the FID resolved that. I assume the spring had been jostled. There was no water in the detector.

The signal is still poor. We have to run several blanks every morning (nothing is turned off) to get started. I also captured a spike/signal drop. Both of the following are blanks.
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