Operating instructions

Charged Aerosol Detectors
Corona Veo and Corona Veo RS
Page 100 Operating Instructions
Problem Probable Cause Remedial Action
The system has very high
backpressure
(Cont'd)
Particulates from the mobile
phase, the column, or injected
samples have accumulated.
Ensure that the mobile phase and/or
samples are filtered sufficiently
before use (e.g. with an in-line
filter).
Use a mobile phase with a
substantial fraction of an organic
solvent to prevent growth of
microorganisms. Observe the
guidelines for mobiles phases
(→ page 41).
Use freshly prepared mobile phase.
Growth of microorganisms in the
mobile phase may lead to clogging
of the filter.
The solubility of the analyte
(standard or sample) in the mobile
phase exceeded.
Start the autosampler and isolate the
pressure spike up to the detector.
Replace the in-line filter elements.
Flush the system using an
appropriate solvent.
Make sure standard and/or sample
are soluble in the mobile phase. Use
diluted sample/standard if
necessary.
The nebulizer nozzle of the
detector is clogged.
Poor solubility of analyte during
nebulization/analyte build-up.
Check the backpressure of the
nebulizer. From the Main Menu, of
the detector, turn off the gas flow.
Remove the nebulizer from the
detector. Carefully flow liquid
through the nebulizer capillary from
the pump. Backpressure of the
nebulizer is typically below 10 bars.
Liquid should exit the capillary in
drops. If the backpressure rises in
the pump, then there is a blockage
in the nebulizer capillary. Install a
new nebulizer (→ Nebulizer
Installation Instructions).
Flush the detector with an
appropriate mobile-phase
composition to solubilize analyte
build-up.