Thermo Scientific Dionex ICS-5000, Operator'S Manual

Page: 159 / 482

4 • Startup
Doc. 065342-06 12/11
143
4.1.2 ED Cell Operating Precautions
To maintain good reproducibility of detection results:
•
Prepare all eluents with ASTM Type I (18 megohm-cm) filtered and
deionized water that meets the specifications listed in
Section 1.5 .
•
Avoid contamination of the cell with incompatible eluents.
•
Never apply potential to the electrode unless a stream of eluent or water is
flowing through the cell.
•
Do not allow a pH-Ag/AgCl reference electrode to dry out. Make sure
that eluent is pumped continuously through the cell. If the cell will not be
used for a short time (less than 2 days), disconnect the tubing from the
inlet and outlet fittings and all fitting plugs. For longer shutdowns, see
Section 6.4 .
•
Be careful to keep the polished surface of the ED cell body clean and dry
when not in use. The gold, spring-loaded (pogo) contact must also remain
clean and dry. If a salt bridge forms, it can cause an electrical short
between the working electrode contact and the cell body.
•
If the conventional (nondisposable) working electrode becomes
discolored or if you notice a degradation in performance (baseline noise,
tailing peaks, etc.), polish the electrode as instructed in
Section 9.28.4 .
•
Over the lifetime of the conventional working electrode, the surface may
gradually become pitted or receded. Receded electrodes can be repaired
by sanding with 600 grit sandpaper. Continue sanding until the metal
surface is again flush with the Kel-F electrode block surface. Then, polish
the electrode (see
Section 9.28.4 ).
•
To help determine when the pH-Ag/AgCl reference electrode needs
regenerating or replacing, monitor the pH value displayed on the detector
panel in Chromeleon (see
page 144 ).
•
To have an alarm displayed in the Audit Trail if the pH exceeds certain
values, set pH limits in Chromeleon (see
page 145 ).