Thermo Scientific Corona Veo, Руководство по эксплуатации

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8 • Troubleshooting
Charged Aerosol Detectors Corona Veo (RS) Operating Manual Page 229
8.5.4.3
Peak Shape and Response
Symptom Possible Cause Remedial Action
Inability to
autozero the
signal Autozero on a peak or
void signal The Autozero occurred on a relatively flat section of the
chromatogram.
Autozero on a very noisy
signal Reduce the noise or increase the current range.
High background signal
on a very sensitive
current range
(background >10x gain) •
Use a mobile phase that provides a lower background (lower
concentration of impurities). Observe the
Mobile Phase
Guidelines for the Detector in section 6.5.1, page 123 .
•
Increase the current range.
Peak broadening Clogging of capillaries,
solvent line filter frits or
sample loop •
Replace the capillaries.
• Check the solvent line filter for permeability. Replace the filter
frit if necessary.
•
Replace the sample loop.
Column overloaded or
contaminated Clean or replace the column.
Reduce the injection volume or injection mass.
Eluent has changed Use freshly prepared solvent. Use HPLC-grade eluents only.
Extra-column volume
too large •
If early peaks are broader than later eluting ones, check the
capillary I.D. and length, sample loop size, flow cell, for example.
•
Use a capillary with a smaller volume for the connection
between column compartment and detector.
Peak fronting Sample or solvent is
stronger than eluent at
time of injection Match sample-solvent strength to the eluent strength at time of
injection.
Peak tailing Extra column volume
too large Use short capillary connections with a suitable inner diameter.
Improper capillary
connections Check capillary fittings for correct placement. Loosen and
retighten fittings. If you use Viper capillaries and fittings, refer to
the
Viper Installation and Operation Guide .
Periodic baseline
fluctuation,
pulsation Air trapped in the
system Purge the system (refer to
Pump Operating Manual
).
Pressure fluctuations
from pump Purge the pump; check general function (refer to Pump Operating
Manual
).