Metrohm 940 Professional IC Vario ONE/ChS/PP/HPG - Manual (Page 72)

5.5 Handling the eluent
￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭
64 ￭￭￭￭￭￭￭￭
940 Professional IC Vario ONE/ChS/PP/HPG (2.940.1340)
Replacing the preheating capillaries
In order to make threading the column input capillary into the column
thermostat's preheating grooves easier, we recommend loosening the
screws for the holder plate a little, but not removing them all the way.
1 Guide the column input capillary into the column thermostat via a
suitable recess (15-1).
2 Push the column input capillary into the outermost of the two pre-
heating grooves (15-2) from the bottom. Continue pushing it
through under the holder plate until it comes back out the top.
3 Carefully bend the column input capillary downward and push it
through the innermost preheating groove until it comes out at the
bottom edge of the holder plate.
5.5 Handling the eluent
Careful handling of the eluent ensures stable analysis results. Keep the fol-
lowing general measures in mind when handling the eluent:
￭ The supply bottle with the eluent must be connected as indicated in
chapter 3.7, page 22. This is particularly important for eluents with vol-
atile solvents (such as acetone).
￭ Avoid condensation in the eluent bottle. Drop formation can change
the concentration ratio in the eluent.
￭ In the case of very sensitive measurements, we recommend that the
eluent be stirred constantly with a magnetic stirrer (e. g. the
2.801.0010 with 6.2070.000).
￭ To protect the IC system from foreign particles, we recommend aspi-
rating the eluent via an aspiration filter (see Chapter 3.7, page 22)
(6.2821.090). This aspiration filter has to be replaced as soon as it
turns yellow but at least every 3 months.
5.5.1 Manufacturing eluent
Chemicals used for manufacturing eluents must have a purity grade of at
least "p.a." They may be diluted only by using ultrapure water (resistance
> 18.2 M
Ω*cm). (These specifications apply generally for all reagents used
in ion chromatography).
Newly manufactured eluents always have to be microfiltered (0.45 µm fil-
ter).