Subtracting Background Spectra - Agilent Technologies 7500 ICP-MS Operator's Manual

Agilent 7500 ICP-MS ChemStation Operator's Manual
Viewing Spectra

Subtracting Background Spectra

It is sometimes useful to be able to subtract background polyatomic species to visu-
ally inspect a spectrum. ChemStation can subtract any data file from another. This
background correction will subtract the abundance of each mass in the background
spectrum from the abundance of the corresponding mass in the spectrum of the cur-
rent data file. It is normally used for graphical purposes. It is not to be confused with
blank subtraction, which subtracts concentration data in quantitative analysis.
To subtract the background spectrum from another spectrum, complete the follow-
ing steps:
1 Select Method>>Data Correction.
The Set Correction dialog box appears.
2 Click Subtract Background.
3 Click Browse.
The Select Data File Dialog box appears, showing the path of the data file directory
and a list of data files.
4 Select a file name from the list by clicking it and then clicking OK.
ChemStation subtracts the data in the selected file from all other data files acquired
with the same method.
5 Select the box, Rejected Masses and enter the masses for which background
spectrum you do not want subtracted.
The background spectrum for the masses you edited in the Rejected Masses box will
not be subtracted. It is used when you do not want to subtract the spectrum for spe-
cific masses; for example the spectrum for internal standards.
6 Click OK.
The net spectrum will be displayed.
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