Metrohm 844 UV/VIS Compact IC - Manual (Page 90)

Table of contents
Storage
Always store the separating columns sealed when not in use and filled
in accordance with the manufacturer’s specifications.
Regeneration
If the separation properties of the column have deteriorated, it can be
regenerated in accordance with the column manufacturer’s
specifications. With the separating columns available from Metrohm,
the instructions for regeneration can be found on the leaflet enclosed
with every column.
In the case of separating columns with carrier material based on silica,
only solutions with pH 2 … 7 may be used for regeneration,
otherwise the columns could be damaged.
4.1.2 High-pressure pump
Pulsation dampener
The MF 6.2620.150 Pulsation dampener belongs to the standard
accessories of the PEEK versions of the 844 UV/VIS Compact IC; its
installation is described in Section 2.6.2. It is used to reduce interfering
pulsation in highly sensitive measurements and also protects the
column material against pressure shocks caused by the injection.
The two steel versions 2.844.0030 and 2.844.0130 are operated
without pulsation dampener.
Maintenance
To protect the pump against foreign particles we advise you to subject
the eluent to microfiltration (0.45 μm filter) and siphon the eluent
through the 6.2821.090 Aspirating filter.
In many cases an unstable baseline (pulsation, flow fluctuations) can
be traced to contaminated valves or faulty, leaky piston seals.
Contaminated valves are cleaned by rinsing with water, RBS solution
or acetone (see Section 4.2.4). When the cleaned valves are reinstalled
you must ensure that the flow direction is correct.
The replacement of piston seals is described in Section 4.2.4.
It is essential to make sure that no precipitation can occur (see also
Section 4.1.3). This could lead to dirty valves, pressure increases and,
in extreme cases, to scratched pistons.
4.1.3 Eluents
Treatment
For the preparation of the eluents only chemicals of a purity degree of
at least "p.a." should be used. Use eluents that are recommended for
spectroscopic detection. For diluting please use only high purity
water.