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Agilent 7500 ICP-MS ChemStation Operator’s Manual
Tuning
Prevention of EM deterioration
When higher signals are analyzed for a long time with very high sensitivity, the EM
may deteriorate fast. EM deterioration causes drift of the signal and the lifetime of
the EM may be shortened. The following methods will minimize EM deterioration:
• Set suitable integration time
Shorten the integration time according to the suitable setting required for the
production of reproducible data. The following table shows the recommended
value of integration time for the prevention of EM deterioration. Please refer to it
and set the integration time for each mass.
Recommended Value for Integration Time
* the sensitivity is 10,000 cps/ppb
These values are only for reference, so please set longer integration times for
your application, if necessary. For more information regarding the settings for
integration time, please refer to Chapter 5, “Creating a method” and the Applica-
tion Handbook.
• Decrease the intensity
When the concentration of signals that you want to analyze is large, high sensitiv-
ity is not required. It is recommended to decrease the sensitivity. If you want to
decrease the intensity, adjust the ion lens voltage (not the EM voltage). To adjust
the ion lens voltage, see “Tuning for Sensitivity” in this chapter.
The Standard of Counts Integration Time Detector Mode
concentration * per Point
< a few 10 ppb 0 to 500Kcps > 0.1sec Pulse
10 ppb to 500kcps to 1Mcps 0.01sec Pulse
approx.100ppb
> approx.100ppb 1Mcps to 4Gcps 0.01sec Analog
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