Waters ACQUITY UPLC M-Class Columns - Manual (Page 5)

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[ CARE AND USE MANUAL ]
Diagnosis 3
 A clogged emitter may still produce an ion signal.
 The charged emitter may act as an APCI needle and ionize the gas
in the source producing ions for the mass spectrometer (below).
Test for a clogged emitter
 If the system pressure drops more than 200 psi the emitter
is clogged.
 Remove the column transfer tubing from the universal sprayer
(or other nanospray source).
Note: In normal use, stop the flow and wait for the pressure to drop
to zero before breaking the connection at the union to minimize
the chance of dislodging potential particulates in the union and
having them be swept into (and clog) the emitter. If one needs to
disconnect to relieve pressure, it is much better to disconnect the
outlet end, as shown here, rather than the inlet.
 The sprayer should be retracted to shut off the high voltage before
touching the sprayer.
 GLOVES MUST BE WORN to prevent contamination with
undesired biological material.
Should your ACQUITY UPLC M-Class Column be replaced?
 Excessive pressure at the column outlet may create a small leak.
 If the column outlet only experiences excess pressure for a short
period of time the column should still be acceptable for use since
the union between packed column and transfer tube can “recover.”
If the column outlet experiences pressure over an extended period
of time (e.g., overnight) the union between the column and the
transfer tubing may be permanently compromised. Any non-
reversible open space created between the column and transfer
line may lead to band broadening (wider peaks).
VII. CHECKING AND CLEANING A FOULED EMITTER
Examine the emitter
 Examining a clogged nanospray emitter under a microscope may
allow the user to determine the source of the clog.
Fused silica particles: These particles will be transparent and have
sharp, fractured edges. Fused silica particles can be created when
a column and an emitter are joined with too much force (over
tightened union).
Organic material: The material will appear brown in color (bottom).
Organic material can derive from a dirty sample or solvents.
Clean emitter
Emitter clogged with organic residue
Examining the Union (Part Number 700002843, available on waters.com).
ACQUITY UPLC M-Class Column Care & Use