Metrohm 851 Titrando - Manual (Page 51)

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5 Operation and maintenance
851 Titrando
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5.2 Generator electrode
5.2.1 Generator electrode without diaphragm
The 6.0345.100 generator electrode without diaphragm is easy to handle
and clean. It needs only one reagent and is quickly ready for use (no mois-
ture deposits in the diaphragm!). The generator electrode without dia-
phragm is suitable for most applications. It should be specifically used for
severely contaminated samples.
5.2.1.1 Reagents
Use only reagents that are specifically intended for generator electrodes
without diaphragms. Details can be found in the documentation of the
reagent manufacturers.
5.2.1.2 Cleaning
As a rule, the electrolyte solution can be exchanged without special clean-
ing of the parts. If cleaning is necessary anyway, ensure that the Pt grid of
the generator electrode is not damaged.
￭ Contaminations containing oil
First clean with a solvent (e.g. hexane), then rinse with ethanol.
￭ Saline depositions
First clean with water, then rinse with ethanol.
Thoroughly dry all parts after cleaning. A hair dryer can be used for this. If
the parts are dried in the drying oven the temperature must not exceed
70 °C (plastic parts!).
5.2.2 Generator electrode with diaphragm
The 6.0344.100 generator electrode with diaphragm should be used for
samples containing ketones, because special reagents for ketones are only
available for generator electrodes with diaphragm. If your reagent has a
low conductivity, e.g. because you have to add chloroform to the sample
due to its solubility, you should prefer the generator electrode with dia-
phragm. It is also recommended when you have to rely on a high accu-
racy in the lowest trace range.
5.2.2.1 Reagents
Reagents for the coulometric water content determination with generator
electrodes with diaphragm consist of the anode solution (anolyte), which
is filled in the titration vessel, and the cathode solution (catholyte), which
is filled in the generator electrode.
For the water content determinations in ketones, special reagents have to
be used (see the documentation of the reagent manufacturers).