Waters Xevo TQD Operator's, Overview And Maintenance Manual page 137

To clean the differential aperture:
Warning:
with biohazardous and/or toxic materials. Always wear
chemical-resistant, powder-free gloves while performing this
procedure.
1. Use the glass-fiber pen to remove gross contamination from the
differential aperture by gentle abrasion.
2. Using 1:1 methanol/water from the wash bottle, flush the differential
aperture.
Doing so removes residual fibers displaced from the
Rationale:
glass-fiber pen.
3. Completely immerse the differential aperture in a glass vessel
containing 1:1 methanol/water.
If the differential aperture is still contaminated after using the
Tip:
glass-fiber pen, use 45:45:10 methanol/water/formic acid.
4. Place the vessel in the ultrasonic bath for 30 minutes.
5. If you used formic acid in the cleaning solution, rinse the differential
aperture by immersing it in a glass vessel containing water and then
place the vessel in the ultrasonic bath for 20 minutes
Caution:
clean, chemical-resistant, powder-free gloves for the following
step.
6. Carefully remove the differential aperture from the vessel, and blow-dry
it using inert, oil-free gas.
The differential pumping aperture can be contaminated
To avoid recontaminating the differential aperture, wear
.
Cleaning the ion guide assembly 4-61