Quattro 2 User's Guide, issue 2. 6666533 - Waters

Quattro II
User's Guide
Changing Between Electrospray and APcI
Changing between the two modes of API operation requires removal of the inner
source in order to fit the appropriate counter electrode components. This can be
achieved without venting the system.
Electrospray
APcI
Discharge
Needle
The counter electrode comprises two finely-machined metal blocks, each with four
holes inclined to the centre line. When assembled the holes align to form four
non-line-of-sight angled pathways.
The counter electrode is sometimes referred to as the “high voltage lens” or the
“pepper pot”.
For early instruments, the blanking plug should be fitted for electrospray while the
discharge needle is essential for APcI operation.
Later instruments are equipped with separate complete assemblies for each mode.
Removing the Inner Source
Release the two screws [item 1] and remove the end flange [2].
If appropriate, disconnect the sample cone voltage supply lead (purple) from the
terminal pin [3]. Some sources are equipped with a spring loaded contact, and
item 3 is absent.
Remove the two plastic-headed thumb screws [4] and withdraw the inner source
assembly (complete with gas tubes, supply cable and O ring) from the stainless
steel housing [5] within the source housing.
Warning: The inner source is heavy and may be hot. Handle with care, using
the cable bracket and HT socket to hold the assembly during removal.
Routine Procedures
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