Metrohm 896 Professional Detector – Amperometry - Manual (Page 40)

6.2 Problems with the baseline
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2.896.0020 896 Professional Detector – Amperometry
Problem Cause Remedy
IC system – temperature
fluctuations. ￭ Switch on column thermostat or column
oven, respectively.
￭ Amperometric detector – Connect preheat-
ing capillary
￭ Amperometric detector – Attach and close
front cover (see Chapter 4.8, page 27).
Measuring cell – Working
electrode contaminated. Clean the working electrode (see the leaflet for
the working electrode).
Measuring cell – Measur-
ing cell leaking. Check capillary connections on the measuring
cell.
IC system – Eluent conta-
minated. Apply new eluent.
Smooth baseline (no
noise). Communications problem
between the amperometric
detector and MagIC Net™. ￭ Check the seating of the electrode cable.
￭ Check the electrode cable with dummy cell
(see Chapter 4.1, page 17).
￭ Switch off the instrument, close and restart
MagIC Net™, switch instrument back on.
All of the data lies outside
of the measuring range. ￭ Adjust measuring range.
￭ Deaerate the measuring cell (see "Deaerat-
ing the measuring cell", page 24).
Short-circuit bridge
between the electrodes. ￭ Examine the working electrode for promi-
nent deposits.
￭ Polish the working electrode (see the leaflet
for the working electrode).
￭ Replace the working electrode .
￭ Clean the measuring cell .
￭ Check spacers.
Reference electrode worn
out. Replace the reference electrode .
The cause is not clear. Perform systematic error diagnostics (see
Chapter 6.9, page 38).
Unexpectedly high
or low baseline. Pd reference electrode –
Working conditions not yet
achieved. Equilibrate until the electrode has adjusted to
the new elution conditions (over night).
DC method – Working con-
ditions not yet achieved. An excessively high baseline is normal at the
start of the equilibration. Equilibrate until the