HP Data Explorer 4 Series - Manual (Page 318)

Chapter 7 Data Explorer Examples
7-2 Applied Biosystems
7
7.1 Mariner Data Examples
This section includes:
• Improving signal-to-noise ratio
• Deconvoluting and evaluating unresolved
chromatographic peaks
• Determining if a peak is background noise
7.1.1 Improving Signal-To-Noise Ratio
Overview You can improve the signal-to-noise ratio for low-level
components in the total ion chromatogram (TIC) by creating
an extracted ion chromatogram for the mass of interest.
Each data point in the TIC represents the sum of all ion
intensities for all masses in the corresponding spectrum. By
creating an extracted ion chromatogram for a specific mass,
you can screen out ion contribution from masses that you are
not interested in.
Creating an
extracted ion
chromatogram
The following example illustrates how you can create an
extracted ion chromatogram to improve the signal-to-noise
ratio for reserpine (609 Da):
1. Display the data file.
2. In the Chromatogram window, click in the toolbar, or
set the Trace Replace mode to Add, if you want to add a
new trace. See Section 2.4.4, Adding Traces from the
Same Data File to a Window, for information.
3. From the Display menu, select Trace, then select
Extracted Ion.
4. In the Extracted Ion Chromatogram window, select
Center/Window, then type the mass of interest (609 Da)
and the window for the mass (for example, 0.5 Da).
5. Click OK.