Thermo Scientific Dionex AS-DV, Operator'S Manual

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4 • Troubleshooting
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Loose or damaged fitting connection(s) to optional high-pressure valve in
the Dionex AS-DV or injection valve in the IC system
1. Make sure the liquid lines to the valve are tight. Replace any damaged
fittings. See Section 5.1 for tightening requirements.
2. Liquid leaks from behind the valve stator may indicate a scratched rotor
seal. Rebuild the injection valve (see Section 5.5 ). Do not overtighten!
4.3 Poor Peak Reproducibility
•
Insufficient sample in sample vial
Always be sure to fill each vial with enough sample to reach the fill line (see
Section 3.1 ). Underfilling a vial will result in a smaller than normal volume
for the first injection and will increase the risk of injecting air.
If the problem continues, overfill the vial slightly. After pushing the cap into
the vial, gently tap any excess liquid from the fill cap socket.
•
Bleed function not turned on when loading a concentrator column
Before loading concentrator column, check that
Bleed
is selected in
Chromeleon (see Section 3.8.2 ). This ensures that a uniform sample volume is
delivered to the concentrator, regardless of how accurately the vials are filled.
Bleed also prevents the introduction of air onto the concentrator column. It
does not, however, compensate for underfilling a sample vial.
•
(TTL Input Control Only) Injection not made during homing delay
before sample tip is retracted from sample
1. Always switch the injection valve to Inject before the end of the homing
delay following the last sample in the vial (see Section C.1 ). Otherwise,
the needle may create a vacuum when it withdraws from the vial and
remove some or all of the sample from the sample loop.
2. Make sure that the injection valve is in Load whenever a sample delivery
is in progress.