Empower Tip: Review Window and the Processing Method

In this tip, we will discuss a feature that was introduced with Empower 3 Feature Release 4 (FR4) called Formula-Based Derived Channel.

Deriving a Channel lets us mathematically combine two channels of data. What if we wanted to combine more than two channels? There is a relatively new feature that lets us combine up to 10 channels of data.

We begin by bringing four individual 2D MS channels (SIR channels) into Review and overlay in a stack plot. What we want to do is combine these four channels into one channel so that we can, for example, perform impurity calculations on the sample much like we did in earlier tips.

Exit out of Review, bring the injection containing the four channels into Review and go to the Method Set window. Right click on Derived Channels, New and select Formula Based Derived Channel.

The Formula Based Derived Channel dialogue box opens.

We start by defining our variables, one variable per channel. In the Variable field select A from the drop down list.

In the Channel field select the first SIR from the drop down list.

Select all variables and all channels for the four channels to be added together.

In the formula field enter A+B+C+D.

Click OK, enter a name for the Derived Channel and select the Processing Method.

Return to the Main Window and Apply the Method Set. Notice the four peaks are now in one chromatogram and the Channel Description reflects the combination.

Click the Peaks tab and now we see the results for the Impurity Analysis.

It’s that easy!