5
Routine and Preventive Maintenance
Maintaining the APCI Probe
Thermo Scientific
Surveyor MSQ Plus Hardware Manual
67
Maintaining the APCI Probe
Flushing the probe on a regular basis helps to prevent contamination and blockage of the
capillary. But even with the best preventive maintenance, occasionally, the capillary can
become blocked.
A significant increase in LC pump backpressure (that is, up to 300 psi at a flow rate of
1 mL/min added to the total LC system backpressure) or instability in the signal can be
symptomatic of a blocked or partially blocked capillary. Replace the capillary if it has become
blocked or partially blocked during operation. The APCI capillary (P/N FM102594) is
pre-sized for the probe, but its installation requires careful alignment.
Follow these maintenance procedures to replace a capillary or clean the APCI probe:
1.
2.
3.
4.
Removing the APCI Probe
Y
To remove the APCI probe from the probe heater
1. Ensure that the flow from the LC pump is turned off.
2. Turn off the nitrogen gas, the probe heater, and the ion optics by doing one of the
following:
• In the Status page of the Xcalibur data system, right-click the Surveyor MSQ listing
and choose
Turn Device Off
from the shortcut menu.
• Or open the Per Method Parameters table in the Tune window. Take the system out
of the Operate mode by clicking the Operate toggle button and turn off the nitrogen
gas by clicking the Nitrogen Gas toggle button. See
.
3. Wait for the source block and the probe heater to cool.
4. Unscrew and remove the PEEK fingertight fitting from the APCI probe. See
.
CAUTION
Wait for the source block and probe heater assembly to cool before changing
ionization modes.
CAUTION
Because it is fragile and can be damaged easily, exercise care when handling
the APCI capillary.
