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Mass Spectrometer Maintenance
Clean SilChrom Ion Trap Electrodes
The silica top surface of the SilChrom Ion Trap Electrode is a very thin (only
about 1
µ
m), but durable layer which is strongly bonded. However,
abrasives
such as alumina powder
must not be used
to clean the trap parts because this
will definitely destroy the silica layer!
Strongly acidic or strongly basic
laboratory cleaners must not be used
to clean the trap parts because they will
also remove the silica layer!
1. For routine cleaning of the SilChrom electrodes, ultrasonicate the ion trap
electrodes for 10 minutes in methylene chloride or methanol. Use separate
beakers for each electrode to avoid scratching trap surfaces. Trap
disassembly and reassembly is otherwise identical to the recommendations
Maintenance Section.
2. If heavy matrix (dirty) samples are routinely run on the instrument and the
electrodes are visibly discolored where the column enters the trap at the
multiplier endcap, one may use a toothbrush and liquid hand soap or dish
detergent (pH between 6 and 7.5) to gently scrub the trap parts. The trap is
rinsed and then sonicated in water followed by two sonications in methylene
chloride or methanol.
DO NOT use Aluminum Oxide or other abrasives because this will remove the
silica layer on the trap!
DO NOT use harsh laboratory cleaners because this will remove the silica layer
on the trap! Use only mild detergent (pH between 6 and 7.5).
NOTE: You will notice that the initial hydrocarbon background is higher than on
the standard ion trap. To speed up the bakeout, you may want to bake out the
ion trap overnight at 250
°
C. In the bakeout mode, the manifold is set to 120 °C.
Clean the Two Quartz or Silica Coated Spacers
NOTE: The Silica Coated Spacers have a shiny, mirror like finish on the inside
surface.
1. Wipe all surfaces of the quartz spacers with a clean, soft, lint-free cloth that
has been dampened with reagent-grade acetone.
2. Subject the quartz spacers to ultrasound in acetone for 5 minutes.
3. Rinse each of the quartz spacers with de-ionized water.
4. Subject the quartz spacers to ultrasound in methanol for 5 minutes.
5. Dry the spacers in air, or in an oven set to approximately 120 °C for 30
minutes.
Reassemble the Trap
To reassemble the trap assembly, proceed as follows, referring to the Ion Trap
Assembly figure:
