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Baseline trouble shooting
Posted: Sat Dec 02, 2017 3:01 am
by Gift
I have a problem with LC-MS/MS baseline. It is spiky with equal frequency. I am not sure how to explain and I do not know how to attach image to this post. Please help.
The instrument pressure is normal based on online calculator.
Re: Baseline trouble shooting
Posted: Sat Dec 02, 2017 8:36 am
by dblux_
I have a problem with LC-MS/MS baseline. It is spiky with equal frequency. I am not sure how to explain and I do not know how to attach image to this post. Please help.
The instrument pressure is normal based on online calculator.
Here you are:
viewtopic.php?f=1&t=2617
Re: Baseline trouble shooting
Posted: Sat Dec 02, 2017 11:01 am
by Gift
Thank you for the tip.
Here is the TIC I was talking about. Blue line is the TIC, red is pressure.
When I changed the dwell time the frequency of the spikes changes too.
Re: Baseline trouble shooting
Posted: Mon Dec 04, 2017 10:53 am
by alcorn
Tune situation? Could you attache an screenshot of your last tune?
Re: Baseline trouble shooting
Posted: Mon Dec 04, 2017 5:20 pm
by lmh
what are you doing? If this is a mass spec method that is carrying out multiple different scans (for example, an MRM method, or a method collecting full scan data and MS2 simultaneously) then a lot of systems will display a total ion chromatogram that is the sum of everything going on, which will naturally zig-zag up and down as the instrument measures first a full scan, or an intense ion, and then an MS2 or weaker ion. When you view the data in software that filters out the appropriate data, they may all turn into nice sensible baselines.