Empower Tip: Review Window and the Processing Method

In Tip 61, we learned how to derive a Timed Mass Chromatogram, creating a channel that specifies a mass at specified starting times. This maximizes sensitivity and allows us to perform quantification for all components regardless of the differences in mass.

STEP 1 Begin by bringing a 3D MS channel into Review, extract a TIC plot, open the Processing Method and integrate the peaks. Note the masses for the peaks.

Select ‘Create Timed Mass Chromatogram’ from the Process menu.

Here we see an overlay, using stack plot of the original TIC plot and the Timed Mass Chromatogram. The Channel Description indicates which is which. Note the difference between the chromatograms.

If we integrate the peak at 3.33 minutes in the original TIC plot, we see a signal-to-noise ratio of 10.9 to 1.

If you integrate the same peak in the Timed Mass Chromatogram, you will see a signal-to-noise ratio of 985 to 1. The chromatogram is much easier to work with in terms of integration and the baseline has far less noise, hence the improvement in sensitivity.