Empower Tip: QDa MS Data in Empower

In this tip, we learn about CODA, Component Detection Algorithm for noisy TIC plots. CODA is a method that was specifically developed for LC/MS data to reduce random noise and high background to simplify the interpretation of the data. CODA retains mass chromatograms that contain information (i.e., analyte peaks) and removes mass chromatograms that add noise.

Let’s see how it’s done!

We start by looking at a noisy TIC plot for a 3D MS channel in Review.

On the MS 3D Channel tab of the Processing Method, enable 3D MS Channel Processing. Then enable CODA with the default settings. CODA is an algorithm designed to reduce random noise and high background to simplify the interpretation of the LC/MS data.

We can compare the original TIC plot (upper plot) with the TIC plot with CODA applied (lower plot) in a stack plot within Review and see a notable improvement in the chromatogram.

Alternatively, you can create a Derived Channel in the Method Set for a TIC plot. Create a second derived channel for a TIC plot and then enable CODA on the MS CODA tab of the derived channel dialogue box.

Create a very simple Processing Method with Inhibit Integration for the entire chromatogram and use that Processing Method for both derived channels.

Applying the Method Set gives us the same result we saw in Step 3.

Either way, the TIC plot with CODA displays improved peak shapes for the small peaks and reveals small peaks that we could not see in the original TIC plot. The advantage to using the Method Set is that you can bring an injection into Review and open/apply the method set and, in a few clicks, I have an improved TIC plot which can be used to further interrogate the peaks.

It’s that easy!