13-3
Agilent 7500 ICP-MS ChemStation Operator’s Manual
Performing a Semiquantitative Analysis
Running a Calibration Sample
Before performing a semiquantitative analysis, it is recommended that the user first
prepares and analyzes a calibration standard to set the element response factors for
semiquantitative calculations. Use a sample containing known concentrations of
three or four elements as a calibration standard for semiquantitative analysis. If the
unknown sample matrix is known, the calibration standard can be matrix matched to
improve the accuracy of the analysis to that approaching full quantitative analysis.
Run the calibration standard prior to running the unknown samples. If you are
analyzing the samples manually, run the calibration standard and then the unknown
samples. ChemStation calculates responses for all elements in the mass spectrum
based on the response to the known concentration of the elements in the calibration
solution. These concentrations of elements should cover the low, medium, and high
ranges of the mass spectrum. A multi-element solution including Li, Y, Ce, and Tl
can be used for calibration of Semiquantitative Analysis. For information about
running the samples, see Chapter 8, “Running a Sample Analysis”.
Viewing the Results of Semiquantitative
Analysis
ChemStation contains original response values for each element in the periodic
table. The higher the response value, the more efficiently that element is ionized in
the plasma, which gives higher sensitivity for a given concentration. These original
response factors have been empirically determined by Agilent Technologies. After
you run the calibration standard and edit the existing semiquantitative parameters,
ChemStation adjusts the original response factors to give “corrected factors”, which
take into account the mass response of the individual instrument. The corrections
can also be reviewed graphically in the response graph.
This section explains how to load a data file, enter concentration values for the cali-
bration elements, correct responses for all elements based on the calibration stan-
dard, and view the response graph.
To Next Page
Loading...
Need help?
General
