Chromatography Forum

I was working on empower software from the last 5 years but I am new to chemstation and now i am struggling to find out how to get peak purity data from this software as it is a DAD .
Can anybody help me to find peak purity using Chemstation (agilent 1200 series DAD detector).

Without getting into the specifics (it has been a while)
tha basic strategy is to use nice flat chunks of baseline on either side of a peak of interest as reference areas, then tell it to compute purity. Instead of a degree (theta?) - you get a number between 1 and 1000 (or is is between 0.0001 and 1?). You can fanagle things (like minimum acceptable peak purity value) somewhat to get things to go your way, so be careful and be certain taht what you print out and present is defensible.

Hope that helps at least a little.

thanks for the information I will try it

First, you must have the "Spectral Module" software installed. If you have a "Spectral" task button in Data Analysis then you are OK.

There is a button (also a menu option) for Peak Purity. Click the button, then click the peak you want to evaluate. The settings are in the Spectra Options dialog. As noted, you can adjust the settings.

The output uses the standard (annoying) "Green is good, red is bad!" approach to labels. You will have to spend some time reading the Help screens and documentation to understand the plots; they are heavily based on statistical analysis of the spectra.

My suggestion is to set the purity threshold for a fixed value of 990. Anything above that is most likely a pure peak. But be aware of the many limitations to this approach. It is not a stand-alone answer. Use it only in combination with other data.