Chromatography Forum

Hi all,

I am using MSD Chemstation (version E) to look at data collected on my GC-FID (which also has an MSD, hence the software). I am not too sure about the unit used for the y-axis on the chromatograms and can't find any way to display it. I understand that this software is more directed towards MS data but is there any way of displaying the FID data in pA?

Thanks for any advice.

This doesn't answer your question, but I'm not sure why it should matter. Since quantitation is based on comparison to standards run under the same conditions, the actual y-axis units are arbitrary.

Thanks for the reply. We are having noise issues on our FID and the Agilent engineer thought it would make things easier for him if he could get an idea of the scale of the signal collected.

Thanks for the reply. We are having noise issues on our FID and the Agilent engineer thought it would make things easier for him if he could get an idea of the scale of the signal collected.

I think with either version of Chemstation you would have problem with the units, since both assign arbitrary units to the signal. The pAmps would be read from the front screen only I believe.

Ok-just wondered if there was an easy way to do it. Thanks for the help.

Hi, all GCMS data is collected as "arbitrary intensity units" or counts. There is no conversion factor to convert between MS data to FID data. However, it is possible to convert the display units for the FID signal (pA) into the display units for the FID signal (counts.)

It is best to use an internal standard or samples of known concentration to check for variability run to run, and for quantitation purposes you would need a calibration curve.

When viewing FID data in MSD Chemstation, I'm sure pretty the conversion factor will be 1.30 x 10^-4 (signal to pA height units).

MSD Chemstation DA 241 -> 1 abundance to pA.