Broken Capillary; Contaminated Insulation Plate - Agilent Technologies 7100 User Manual

6 Troubleshooting and Diagnostics
CE Problem Solving

Broken Capillary

To check for a broken capillary, remove the capillary cassette and open it as
described under
Instrument"
the detection window and the capillary ends, therefore check these parts of
the capillary. If the capillary is broken at the detection window, a leakage
current of nearly the same value as the expected current may occur.
Small instabilities in the current curves, as shown in
sign of a broken capillary.
Figure 51
If the capillary is broken at the ends, it may no longer reach into the liquid in
the vial. In that case, the analysis is stopped if the low current alarm limit has
been reached (this must be set first). Sometimes the capillary has very small
cracks which are hardly recognizable under a microscope.
• Exchange the broken capillary

Contaminated Insulation Plate

Salt crystals or other contamination of the insulation plate may cause leakage
current.
• Clean the insulation plate as described in
166
"Removing the Capillary Cassette from the Agilent CE
on page 121. The capillary is especially sensitive to breaking at
Current instabilities
page 207.
"Cleaning the Insulation Plate"
Agilent 7100 Capillary Electrophoresis System User Manual
Figure 51, may also be a
on