Chromatography Forum

It seems I chose the wrong reference wavelength. So my peaks are negative. Does anyone know if I can change the reference wavelength and reprocess the data or can I use "isoabsorbace plot" function to somehow correct it?

In iso-absorbance mode (at least in my outdated version A.6.4) you can set new reference wavelengths and new signal wavelengths within the wavelength range you have stored. So if you store only the UV range from 200 nm to 400 nm, you will not be able to have a reference in the visible. The other problem may be that you have stored only the spectra in the peaks and not every spectrum. This will restrict your reprocessing on identified peaks of the A-signal.

Best regards,

This is the first time for me to use "iosabsorbance"function. I played with the horizontal and vertical cursors. I did extract the chromatograms shown in the bottom window and spectrum in the upper window. But I haven't found where to set up new ref. wavelength? And how can I integrate the new extracted chromatograms and print them out?

Thank you for your information. I really appreciate!

Apple

In isoabsorbance plot in the top-left hand corner set cursor to signal. Then you have the chance to enter signal and reference wavelengths and bandwidths manually (or with the mouse). Note that the applied changes will not become visible before you click into another field in this corner. With Copy and Exit you get a chromatogram which you then can integrate.

Good Luck!

Thank you K.H.W for your information. I did extract the chromatograms I want. Very appreciate your help!

Apple