Checking The Argon And Nitrogen Supplies; Checking The Esi Fused-Silica Sample Tube For Elongation; Checking The System Vacuum Levels - Thermo Scientific TSQ Series Hardware Manual

4
Daily Operation
Things to Do Before Operating the TSQ System

Checking the Argon and Nitrogen Supplies

Check the argon supply on the regulator of the gas tank. Make sure that you have sufficient gas for
your analysis. If necessary, install a new tank of argon. Verify that the pressure of argon reaching
the mass spectrometer is between 135 ± 70 kPa (20 ± 10 psig). If necessary, adjust the pressure
with the tank pressure regulator.
Check the nitrogen supply on the regulator of the nitrogen gas tank or liquid nitrogen boil-off
tank. Make sure that you have sufficient gas for your analysis. Based on 24-hour per day operation,
typical nitrogen consumption is 2800 liters per day (100 cubic feet per day). If necessary, replace
the tank. Verify that the pressure of nitrogen reaching the mass spectrometer is between
690 ± 140 kPa (100 ± 20 psig). If necessary, adjust the pressure with the tank pressure regulator.
CAUTION Before you begin normal operation each day, ensure that you have sufficient
nitrogen for your API source. The presence of oxygen in the ion source when the mass
spectrometer is on could be unsafe. The TSQ system displays a pop-up message if the nitrogen
pressure is too low.

Checking the ESI Fused-Silica Sample Tube for Elongation

Using acetonitrile in the mobile phase can cause elongation of the polyimide coating on the
fused-silica sample tube. Elongation of the polyimide coating can degrade signal intensity and
signal stability over time.
If you are running in ESI mode with a fused-silica sample tube, verify the sample tube is not
elongated past the tip of the ESI spray needle. (This elongation does not occur with a metal
needle.)
To cut and reposition the sample tube approximately 0.5 mm (between 0 and 1 mm) inside the
end of the ESI needle, refer to the Ion MAX and Ion MAX-S API Source Hardware Manual for more
information.

Checking the System Vacuum Levels

For proper performance, your TSQ system must operate at the proper vacuum levels. Operation of
the system with poor vacuum levels can cause reduced sensitivity, tuning problems, and reduced
lifetime of the electron multiplier. You should check your system for air leaks by checking the
system vacuum levels before you begin your first acquisition.
You can check the current values of the pressures in the ion transfer tube-skimmer region and
foreline (labeled Fore Press) and in the analyzer region (labeled Gauge Press) in the Instrument
Information Center (upper right corner) of the Tune Master window – Full Instrument Control
workspace. To display the Tune Master window, from the Windows taskbar choose Start > All
Programs > Xcalibur > Quantum Tune. Choose Workspace > Full Instrument Control to display
the Full Instrument Control workspace.
Compare the current values of the pressures in the vacuum manifold with the values listed in
Table
58 TSQ Series Hardware Manual
3. If the current values are higher than normal, you might have an air leak.
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