Chromatography Forum

Recently upgraded to OpenLab CDS Chemstation edition on a LC/DAD/MS system. I have the DAD detector set to collect/store the spectrum at Apex+Baselines (190-400 nm). When I load up the data file and try to extract the spectrum from integrated peaks, I get the message "No spectra within peak available" - I tried modifying some options in the spectrum collection details, to no avail. Some of the peaks are almost identical in shape/height so I can't figure out why it wouldn't have stored the spectra at that point and I never had this problem on my older LC. I keep thinking I must be missing something obvious?


Thanks

Hello

1.Try to store "all" spectra - perhaps it is bug in OpenLab and it is not working for "apex peak + baseline" (I've seen this in the past)
2.Make sure you have file with spectra in data folder (it is *.UV)
3. The peak detection is done by the detector firmware based on the threshold and peakwidth parameters you
set for the DAD. If you're using peak-controlled spectra storage, make sure that you set these parameters to recognize all the peaks of interest. The integration algorithm also includes peak detection based on the threshold and peakwidth parameters set in the integration events.

If it works, it is something with your method setting for spectra collection.

Regards

Tomasz Kubowicz

Hi there,
I have had similar problems on occasion especially with signals from a Agilent HP1100 fluorescence detector. I have never found the cause of the problem and would be interested if you did. I tried similar things to those suggested by Tomasz with no luck. In the end I resolved the problem by starting with a fresh method and setting up parameters from default.m
It may be think that the method I was using was somehow corrupt but I didn't pursue it further.

Kevin

Hi there,
I have had similar problems on occasion especially with signals from a Agilent HP1100 fluorescence detector. I have never found the cause of the problem and would be interested if you did. I tried similar things to those suggested by Tomasz with no luck. In the end I resolved the problem by starting with a fresh method and setting up parameters from default.m
It may be think that the method I was using was somehow corrupt but I didn't pursue it further.

Kevin

It's been a while, but it does seem you were correct tkubowicz - selecting 'all' seems to fix the issue so I'm gonna assume it is in fact a bug.


Thanks!