Metrohm 791 VA Detector - Manual (Page 25)

3.1 Electrochemical detection
791 VA Detector
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sulfuric acid, perchloric acid, lithium perchlorate, etc. can be used for
this. Chlorides and hydroxycarboxylic acids should not be used; some
reagents which form ion pairs can be used.
Solvent gradients can be used in less sensitive ranges (current range >
100 nA). The eluent is degassed as usual by vacuum or passing a
stream of helium through it.
Stationary phase
In principle all reversed-phase and ion exchanger materials can be
used. New columns must be purged well and for a sufficiently long time
for any contaminants which may be present to be washed out. This
"equlibration phase" of a column may take more than 24 hours in the
most sensitive areas.
Sample solution
Whenever possible, the eluent used should also be used as the solvent
for the sample in order to minimize interference owing to changing sur-
roundings (as small a front peak as possible). Very small amounts of
the active substance should be used, in general < 100 ng.