Not identifying calibrated peaks

[sslusher]

Hello, I'm having a problem with calibrated peaks not being identified even though a peak is being identified at the same retention time the calibrated compound is set up. Any ideas?

[Steve Reimer]

CDS = ?
calibrated peak integrated?
peak entirely within retention time window?
type of detector?

Lots of ideas, no data to go on.

[kubowicz.tomasz]

Hello

It looks like you have to specify range for peak identification - it is normally expressed as ∓ % of retention time for calibrated peak.

For example in Agilent Chemstation it is in "calibration options"

Regards

Tomasz Kubowicz

[sslusher]

We are using Chem Station version B.03.02. and an FID detector.

To better illustrate- the compound is calibrated at a RT of 2.94 +/- 1% (or 0.01 min). A peak will show at exactly 2.94 but will not be identified as my calibrated compound, instead, it will have two times listed at 2.94- one with a line through it and the name of the compound, the other with a question mark and the peak.

[Peter Apps]

My guess is that if you expand the time scale several times you will find that the peak is slightly flat on top and that the integrator finds two apices separated by less than 0.01 min. You need to play with slope and peak width settings to stop the integrator seeing noise at the apex as a peak end and beginning.

Peter

[sslusher]

Thank you for the suggestion; I will make adjustments and see if my readings improve.