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Agilent 7500 ICP-MS ChemStation Operator’s Manual
Creating a Method
Prevention of EM deterioration
When higher signals are analyzed for a long time with too high sensitivity, the EM
may deteriorate fast. EM deterioration causes the drift of the signal and the lifetime
of the EM may be shorten. The following methods will prevent EM deterioration:
• Set suitable integration time
Shorten the integration time according to the suitable setting required for the pro-
duction of reproducible data. The following table shows the recommended value
of integration time for the prevention of the 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 the longer integration time
according to your application, if necessary. For more information regarding the
settings for integration time, please refer to Chapter 5, “Creating a method” and
the Application Handbook.
• Decrease the intensity
When the group of signals that you want to analyze is large, high sensitivity is not
required. It is recommended to decrease the sensitivity. If you want to decrease
the intensity, adjust the ion lens voltage (not 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
A few 10 ppb to 500kcps to 1Mcps 0.01sec Pulse
approx.100ppb
> approx.100ppb 1Mcps to 4Gcps 0.01sec Analog
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