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Dionex ED50A Electrochemical Detector
polyester substrate is used, the percentage of methanol should not exceed 30%
and the percentage of acetonitrile should not exceed 10%. In addition, prolonged
exposure (more than 8 hours) of disposable gold electrodes on polyester substrate
to eluents containing hydroxide concentrations greater than 100 mM is not
recommended. Shorter rinse periods of 10 to 20 minutes (for example, the
carbonate removal step during monosaccharide and disaccharide
chromatography) at high hydroxide concentrations do not affect the electrode
performance. If sustained highly alkaline eluent conditions are required, use a
disposable gold electrode on a PTFE substrate or a conventional gold electrode.
Refer to Product Manual for Disposable Electrode (Document No. 065040) for
additional eluent compatibility information.
Because conventional working electrode blocks are made of Kel-F
gasket made of Ultem
solvents that can be used with them (providing the solvent is compatible with
PEEK tubing).
There is also no restriction on the use of organic solvents when disposable gold
electrodes on PTFE substrate and PTFE gaskets are used.
Adding a Second Detector
The Dionex ED50A amperometry cell is installed directly after the column (a
suppressor is generally not used). A second detector can be installed in-line with
the amperometry cell, as long as the pressure at the amperometry cell inlet
remains less than 700 kPa (100 psi). Because of the volume within the reference
electrode section of the cell (67
broadening at the second detector. However, this is minimized by the precision
flat-bottomed reference electrode.
2.4.1
Combination pH
The reference electrode is a standard combination pH electrode
containing a glass membrane pH half-cell and a Ag/AgCl half-cell. The
combination pH electrode monitors mobile phase pH, which is displayed
on the
The Ag/AgCl half-cell is typically used as the cell reference electrode.
The combination pH–Ag/AgCl electrode can be used as the reference
electrode during a pH gradient, to minimize changes in the baseline. The
potentials at which many redox reactions take place on metallic electrodes
are pH-dependent, with the potential shifting -0.059 V per pH unit. This is
2-12
®
, there is no restriction on the concentration of organic
L total cell volume), there may be some band
Ag/AgCl Reference Electrode
–
and
screens and is also available as an analog output.
MAIN
DETAIL
®
and use a
Doc. 065551-01 6/13
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