Chromatography Forum

Hello all

I'm having problems with chemstation assigning the correct label to peaks for calibration.
I am using Chemstation B.04.01 SP1 with Chemstore version B.04.02

Basically, I'm analysing catecholamines and have 3 compounds/peaks at 7, 8 and 10mins.
I'm injecting standards that contain all 3 compounds in one injection, at various levels. The peaks tend to drift quite a bit over the course of a run, general retention time windows do not work. But these can be assigned compound names relatively easily with the use of 'corrected retention time' in relation to a 'ref' peak. As the peak at 8mins is always larger than the rest.

However the problem comes when I then process all the samples. As the levels of the 3 compounds varies significantly in the samples the 'ref' peak is not always the largest. Therefore I regularly get incorrect labeling of peaks.
Is there anyway of manually assigning these peaks the correct label? Or can anyone suggest a more reliable with of automatically doing it?

Thanks

Hi

I am not at work so can not double check, but if I recall right there is a default setting for the peak recognision window in the calibrations settings, when you name/lable peaks the windows shows up like a blue bar. You can expand this default setting, but do not recall exactly where.

I am not at work so can not double check, but if I recall right there is a default setting for the peak recognision window in the calibrations settings, when you name/lable peaks the windows shows up like a blue bar. You can expand this default setting, but do not recall exactly where.

I'm not at work either. but go to Calibration, Calibration Options/Edit Options, and there is a table of available options for the Cal Table on the left. Highlight Ret. Time Low Bound and move it to the right, then do same for Ret. Time High Bound, then click OK These then show up on the Cal Table, and you can type in different times to broaden or narrow your retention time blue window. Remember, just the apex of the peak needs to be in the window, not the entire peak.

Cheers guys.
I definitely be giving this a go next time. I had to go through all the injections and do manual calculations this time.