Agilent Technologies 7500 ICP-MS

4-49
Agilent 7500 ICP-MS ChemStation Operator’s Manual
Tuning
H
2
Mode (When Hydrogen is used as Reaction Gas)
It is recommended to tune in H
2
mode after tuning in standard mode.
Autotune cannot be used in H
2
mode
The following is an example of the sensitivity tuning method in the H
2
mode. This
is assuming that tuning in the standard mode is completed. First, tune the lens
voltage under the appropriate H
2
flow rate, and then adjust the H
2
flow rate.
1 Adjustment of Lens Voltage
a.Save the tuning parameters in standard mode.
b.Aspirate the tuning solution and confirm that Co (59 amu), Y (89 amu), and
Tl (205 amu) show normal 7500ce counts on the ICP-MS
Tuning-Sensitivity Window.
c.Turn Reaction Mode Check Box ON and set the value to 5 mL/min. for the
H
2
Gas flow.
d.Set the QP Focus to -15V, the OctP Bias to -18V, and the QP Bias to -16V.
Use the values from Standard Mode for the following parameters;
• RF Power
• Sampling Depth
• Carrier Gas
•Makeup Gas
• Torch-H, V
• Extract 1
• Extract 2
• Omega Bias -ce
• Omega Lens-ce
• OctP RF
e.Maximize the sensitivity of Y (89 amu) by adjusting Cell Entrance, QP
Focus, and Cell Exit. If the sensitivity is low, change the Cell Exit to a lower
voltage. In this case, sometimes, the background may increase. Monitor the
background when adjusting.
f. Adjust the Makeup Gas and choose a value that gives maximum sensitivity.
g.Readjust the Cell Entrance, QP Focus, and Cell Exit to obtain best
sensitivity.