Metrohm 817 Bioscan - Manual (Page 64)

5 Notes – Maintenance – Faults
817 Bioscan
56
Regeneration
If the separation properties of the column have deteriorated, it can be
regenerated in accordance with the column manufacturer’s specifica-
tions. With the separating columns available from Metrohm (see sec-
tion 6.3.2), 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.
5.1.2 High-pressure pump
Pulsation absorber
For determinations using the Bioscan pulsation-free high-pressure
pumps with very constant flow rates are needed. However, if pulsation
is too high, the use of the 6.2620.150 Pulsation dampener MF is rec-
ommended. It is also used to protect the column material against pres-
sure shocks caused by the injection. Its installation is described in sec-
tion 2.3.2.
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. When the cleaned valves are reinstalled, you must ensure
that the flow direction is correct.
The replacement of piston seals has to be done in accordance with
the pump manufacturer’s directions. The corresponding maintenance
work for the 709 IC Pump is described in section 4.2 of the 709 Instruc-
tions for Use.
Salt crystals between the piston and the seal are the cause of abrasive
particles, which can enter the eluent. These lead to contaminated
valves, pressure rise and in extreme cases to scratched pistons. It is
thus essential to ensure that no precipitates can appear (see also
section 5.1.3).