Metrohm 883 Basic IC plus Manual page 86

4.10 Suppressor
4.10.3.2 Regenerating the anion suppression rotor
78
￭￭￭￭￭￭￭￭
If the anion suppressor units are loaded with certain heavy metals (such as
iron) or organic contamination for long periods, then the standard regen-
eration solution may no longer be able to completely remove them. This
constantly reduces the capacity of the suppressor units, which results in
reduced phosphate sensitivity in mild cases and a large increase in the
baseline in severe cases.
If such capacity problems occur at one or more positions, all anion sup-
pressor units must be regenerated with one of the following solutions:
Regeneration solutions
Contamination with heavy metals or elevated backpressure:
￭
1 mol/L H SO + 0.1 mol/L oxalic acid
2 4
Contamination with organic cationic complexing agents:
￭
0.1 mol/L H SO / 0.1 mol/L oxalic acid / acetone 5%
2 4
Heavy contamination with organic substances:
￭
0.2 mol/L H SO / acetone ≥ 20%
2 4
Contamination by certain environmental samples
￭
1 mol/L H PO
3 4
NOTICE
If phosphoric acid has been used once as regeneration solution in an IC
system, you will have to continue using phosphoric acid for regenera-
tion. Regenerating it with sulfuric acid again can lead to problems in the
baseline.
CAUTION
Pump tubing made of PVC must not be used for solutions containing
organic solvents.
We recommend using the high-pressure pump for regeneration.
Regenerating the anion suppressor rotor
1 Disconnecting the Metrohm Suppressor Module (MSM) from
the IC system
Disconnect the capillaries of the MSM labeled regenerant and
￭
rinsing solution from the IC system.
￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭
883 Basic IC plus