Entering Minimum Peak Value - Agilent Technologies 7500 ICP-MS Operator's Manual

3 Type the concentration for the selected element and click Enter.
4 Repeat these steps for each element in the calibration solution.
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Agilent 7500 ICP-MS ChemStation Operator's Manual
Performing a Semiquantitative Analysis
The concentration value appears in the Conc field for the selected element.
If you want to enter the same concentration value for multiple calibration elements,
you can press Control and then click the Conc field for each element in the
calibration solution. Then, enter the concentration value and click Enter.
ChemStation inserts the same concentration value for all the elements you select.
Remain in the Edit SemiQuant Parameters dialog box to view the responses for the
other elements; that is, those elements that are not in the calibration solution. As
mentioned earlier, 3-4 elements covering the mass range are usually sufficient to
produce corrected responses for all other elements. See "Correcting Responses for
All Elements" in this chapter for instructions.
SemiQuant response factors for all elements that are not present in the standard are
calibrated in the following way:
The initial SemiQuant response stored in the software for a given element is adjusted
using a factor derived from the corrected responses obtained for elements used in the
SemiQuant calibration.
The nearest two elements on the high mass and low mass sides of the non-calibrated
mass are used. A line is drawn between these two masses, and a factor calculated at
the mass of interest. If the mass of interest is lower than the lowest mass used in the
SemiQuant calibration, then the factor obtained for the lowest mass is applied. The
same method is followed if the mass of interest is higher than the highest mass used
in the SemiQuant calibration.

Entering Minimum Peak Value

Enter the minimum cps that must be present for a given mass in order that the
element corresponding to that mass is recognized as being detected in the sample. If
the cps for a mass is greater than or equal to the Minimum Peak value, semiquant
analysis will calculate and report a concentration for that element. If the cps for a
mass is less than the Minimum Peak value, the corresponding element will be
reported as "< xxx", where "xxx" is equal to concentration that would be derived
using the Minimum Peak value and the semiquant factor for the element in question.
The default value is set to 50 cps.
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