Chromatography Forum

Hi,

Is there any way I can integrate peaks accquired at 2 (or more) wavelengths simultaneously and have it shown in the excel spreadsheet after batch output in Chemstation?

After setting integration parameters and calibration at 2 wavelengths, as well as processing my sequence (steps did sequentially), peak areas obtained at both wavelengths are shown in the PDF report.

Following these steps, I did batch processing, but only peak areas from 1 wavelength are transferred into the excel spreadsheet.

What can I do to have peak areas from 2 wavelengths to be transferred into the excel spreadsheet? Or did I miss any step that should be done?

I did try to google and read the manuals, but I'm not getting any useful information I can understand from them.

Thanks in advance for any comments/advice.

If you're doing batch reprocessing, then you've presumably specified the peaks you want to export (i.e. it's a method looking for predefined chemicals at predefined retention times). I think the problem may be that Chemstation ("New Calibration Table") assumes that all peaks eluting at 1.23minutes are the same chemical, and therefore regards one of the signals as the thing for quantification, and the rest as mere qualifiers.

If so, you can go to the calibration table, manually delete the rows that are not being exported (the qualifier rows, which have a blank in the "#" column; mark these rows and use the delete button). Then you can add the peaks manually using the "insert" button when displaying the calibration table. You will have to choose what to insert ("Compound") and then enter the retention time and state what signal you want to use. This allows you to have multiple "compounds" with the same retention time, the multiple compounds coming from different signals. I'm not so clear on how this works with DAD signals, but it's what I do all the time with MSD signals, especially where I have coeluting internal standards and analytes.

Hi,

I tried to do what was mentioned, but I kept getting negative calibration for the second DAD signal (DAD B), when both DAD A and DAD B are added into the calibration table.

The only way that works now is to add only DAD A into the calibration table, process the data then set up quantification again, add only DAD B into the calibration table now and reprocess the data.

I tried using other options as well, but none works. Thanks for the info though! I am just not sure if I am doing anything wrong or if it only works with MSD signals.

Anyone else has experience quantifying two wavelength signals simultaneously?