Metrohm 792 Basic IC - Manual (Page 153)

5 Notes – Maintenance – Faults
792 Basic IC
144
5.2.3 Recycling
To keep the eluent consumption between injections to a minimum when
the system is at rest (e.g. overnight), the so-called recycling procedure
can be used. In recycling the eluent exiting the outlet capillary of the de-
tector block is led back directly to the eluent supply vessel. The IC sys-
tem is thus quickly ready for new injections without a long conditioning
period.
The recycling procedure must not be used
x in operation with the suppressor module,
x with alkaline eluents,
x with the 6.1010.000 IC Cation column METROSEP Cation 1-2.
5.2.4 Shutdown
If the 792 Basic IC is shut down for a considerable length of time, the
entire IC system ( without column and suppressor) must be rinsed
free from salt with methanol/water (1:4) to avoid crystallization of elu-
ent salts with the corresponding subsequent damage.
For rinsing, the connections to the separating column and the suppres-
sor module are removed; the two capillaries 20 20 20 20 and 37 37 37 37 (see Fig. 12 and
Fig. 14) are directly connected to each other using coupling 26 26 26 26
(6.2620.060). Rinse with methanol/water (1:4) until the conductivity
drops below 10 PS/cm.
5.2.5 Changing separating columns
Identical separation system
If you wish to replace an IC separating column by a column of the same
type, proceed as follows (see Fig. 12 and Fig. 14):
1 Remove old column
x Switch off high-pressure pump and wait for pressure to drop.
x Unscrew column 66
66 66 66 from inlet capillary 37 37 37 37 of the detector
block or from suppressor inlet capillary 75 75 75 75.
x Unscrew column 66
66 66 66 from column connection capillary 20 20 20 20 or
the precolumn.
2 Connect new column to injector
x Remove end caps from column 66 66 66 66.
x Screw inlet end of separating column 66
66 66 66 (note flow direction)
to column connection capillary 20 20 20 20 or to the precolumn (see
section 2.7.7/section 2.7.8).