Get Empowered: Review Window and the Processing Method | Tip #65, Deriving Channels

By April 18, 2018

Tip #65: Deriving Channels in Empower (Part 18)

Welcome back to Get Empowered! In our last tip-of-the-week blog for Empower Software, we reviewed Deriving Channels when working with 3D MS chromatography data in Empower.

  • Tip 47: Smooth a chromatogram by Deriving a Channel (part 1)
  • Tip 48: Correct for the time offset between detectors connected in series by Deriving a Channel (part 2)
  • Tip 49: Subtract a baseline from a 2D chromatogram by Deriving a Channel (part 3).
  • Tip 51: Subtract a 2D baseline from 3D PDA data by Deriving a Channel (part 4).
  • Tip 52: Derive MaxPlot from 3D PDA data (part 5)
  • Tip 53: Derive TotalPlot from 3D PDA data (part 6)
  • Tip 54: Derive RatioPlot from 3D PDA data (part 7)
  • Tip 55: Derive Timed Wavelength from 3D PDS data (part 8)
  • Tip 56: Derive Single Mass from 3D MS data (part 9)
  • Tip 57: Derive TIC plot from 3D MS data (part 10)
  • Tip 58: Improve noisy TIC plot Derived from 3D MS data (part 11)
  • Tip 59: Derive MaxPlot from 3D MS data (part 12)
  • Tip 60: Derive Total Plot for 3D MS data (part 13)
  • Tip 61: Derive Timed Mass for 3D MS data (part 14)
  • Tip 62: Create a Formula Based Derived Channel (part 15)
  • Tip 63: Create a mirror image of a chromatogram (part 16)
  • Tip 64: How to look at the second derivative of a chromatogram (part 17)


In this final tip in the Deriving Channels in Empower series, we are going to learn how to use a derived channel function called Switch To.

Many methods call for collecting data at two different wavelengths with a UV detector or perhaps using two different detectors in series such as UV and fluorescence. Depending on the compounds you are analyzing, some may respond better with one detector versus another. In these cases, we collect and must process two channels of data. Wouldn’t it be nice to combine the two chromatograms into one so that you only process one channel? You can and it’s easy.

Let me show you how it is done.

Step 1

We begin by bringing a Sample Set into Review, open, and apply the Method Set (Figure 1). We see that peaks 1 and 2 respond well at 212 nm, whereas peaks 3 and 4 have a better response at 224 nm.

Empower Tips: Open and apply the Method Set | Figure 1

Figure 1

Step 2

Go to the Method Set, Derive a Channel and on the First (Only) Tab select the first channel from the Channel drop-down list (Figure 2).

Empower Tips: Select the first channel from the Channel drop down list | Figure 2

Figure 2

Step 3

On the Second Channel tab, select Switch To from the Operator drop-down list (Figure 3).

Empower Tips: Select Switch To from the Operator drop down list | Figure 3

Figure 3

Step 4

Select the Second Channel from the Channel drop-down list (Figure 4).

Empower Tips: Select the Second Channel | Figure 4

Figure 4

Step 5

Enter the Switch at Time in minutes (Figure 5). Note the equation that Empower creates.

Empower Tips: Enter the Switch at Time | Figure 5

Figure 5

Step 6

Click OK, enter a name for the Derived Channel, and be sure to select the Processing Method in the table (Figure 6).

Empwoer Tips: Enter a name for the Derived Channel | Figure 6

Figure 6

Step 7

Return to the Main window and apply the Method Set (Figure 7).

Empower Tips: Apply the Method Set | Figure 7

Figure 7

Step 8

The new chromatogram displays the first channel starting at 0 and switches to the second channel at 0.9 minutes. Now we can process the one channel in which we have optimized the response of all components.


It’s that easy!

Final Notes:

  1. You must have Empower 3 FR2 or higher to use this feature.
  2. This procedure can be followed using the QuickStart or Pro interface.


Please rate this Empower Tip of the Week


Next week in Empower Tip #66  Working with Method Sets (part 1).


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