Reducing Oxide Ions; Reducing Doubly Charged Ions; Scan Of The Octopole - Agilent Technologies 7500 ICP-MS Operator's Manual

Agilent 7500 ICP-MS ChemStation Operator's Manual
Tuning
N O T E It is recommended that the 2 tuning items, "EM" and "Resolution / Axis", are
executed in standard mode. Autotune is executed with higher sensitivity in standard
mode. In cool mode, execute Autotune without "EM" and "Resolution / Axis".

Reducing Oxide Ions

The reason for tuning to reduce Oxide ions is the same as other Agilent 7500 series.
For details, refer to "Reducing Oxide Ions" on page 4-12.
The typical value of oxide ions is less than 10% in standard mode.

Reducing Doubly Charged Ions

The reason tuning to reduce Doubly Charged ions is the same as other Agilent 7500
series. For details, refer to "Reducing Doubly Charged Ions" on page 4-15.
The typical value of doubly charged ions is less than 10% in standard mode.

Scan of the Octopole

Generally, the RF voltage of the Octopole is fixed at a certain value, this has no
effect for selecting the mass of an element to be measured. However, when an
element of low mass is measured with higher sensitivity, the RF voltage of the
Octopole can be scanned by working with the Q-pole Scan. Be careful about the
stability of signals because the scan of Octopole may increase the factors to make
the instrument unstable.
Scan line of RF voltage
Scan of the Octopole RF voltage will have a scan line as shown in the following
figure. The RF voltage will rise in proportion to the mass on the low mass side the
voltage will be constant on masses number larger than the bend mass number.
If the Octopole is not scanned, the voltage will be constant (OctP RF) on all the
mass numbers.
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