Thermo Scientific thermoscientific Vanquish UHPLC System, Руководство по эксплуатации

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8 • Troubleshooting
Page 118 UHPLC System
Operating Manual
Pump problems
Possible Cause Remedial Action
Piston seals in pump
leaking Replace the seals (refer to Pump Operating Manual ).
Air trapped in pump
head Purge the pump (refer to Pump Operating Manual ).
Baseline fluctuations See "Periodic baseline fluctuations" in Baseline ( } page 121) .
Pump pulsation or flow
fluctuations See "Pressure pulsation or inconstant pressure" in Pressure ( } page 120) .
Irreproducible gradient Change the gradient.
Check the solvent line filters for permeability. Replace the filter frits if necessary
(refer to
Pump Operating Manual ).
Inappropriate detector settings
Possible Cause Remedial Action
Improper wavelength,
e.g., in a UV spectrum
flank Choose a detection wavelength that is located near the apex of the spectrum.
Detector response time
too short Select a longer response time.
Detector response time
too long Peaks are eventually not separated any more. Select a shorter response time.
Injection volume variation
Possible Cause Remedial Action
Autosampler draws air
from vial There is not enough amount of sample in the vial, the needle height setting is
incorrect, or there are too many replicates.
Air trapped in
autosampler flow path Perform a wash cycle. Check that the injection valve is in Inject position and the
flow components of the autosampler are flushed with solvent.
Draw speed too high Select a lower draw speed.
Gas content of sample
too high or saturated Reduce the draw speed. Degas the sample if possible.
Injector needle clogged
or needle tip deformed Replace the needle (refer to Split Sampler Operating Manual ).
Piston seals in
autosampler metering
device leaking Replace the metering device head (refer to Split Sampler Operating Manual ).
Injection valve or other
autosampler
components leaking Inspect the autosampler and the connections on the injection valve. Tighten leaking
connections. Replace leaking parts (refer to
Split Sampler Operating Manual ).
Needle seat worn out Replace the needle seat (refer to Split Sampler Operating Manual ).