Chromatography Forum

I am collecting 4 channels (2 UV/VIS wavelengths and 2 fluorescence emmissions = 4). I am able to collect all four channels with each injection (just trying to calibrate now). But that is where I am stumped. I have no experience with Empower. Do I need different processing methods for each channel or can I do it with one?

You can process multiple channels with only 1 processing method, as long as all the events and RT windows work for all of your detectors. Typically, with 4 detectors in line, the Rt of your components will be increasingly longer. As long as the resolution of your components is sufficient, you can make your RT windows big enough to be able to correctly identify the peaks. Another consideration is the noise for a fluorescence detector usually going to be greater tha a UV detector, so you may want to ensure that the integration is good for all the chromatograms. All you need to do to process all 4 channels using the same proc. method is to put all 4 channes in your method set and indicate the appropriate processing method for all.

As suggested, you can use a single processing method if this works or you could also use a different processing method for each data channel...,

To account for the different retention times from channels from different detectors (different tubing lengths!) you can use the filter/ offset tab of the derived channels in the method set or in each processing method (if different processing methods are used) and set an RT offset to normalise the channels.

Hope this helps,
Ben