Metrohm 732 IC Detector - Manual (Page 147)

5 Notes – Maintenance – Faults
732 IC Detector / 733 IC Separation Center
140
5.2.6 Regeneration of the suppressor
Regenerating a suppressor operating at
reduced capacity
If the suppressor units are exposed to certain heavy metals (e.g. iron)
or organic contaminants for long periods of time, these can no longer
be completely removed by the regeneration solution normally used (20
mmol/L H
2
SO
4
). This diminishes the capacity of the suppressor units,
which, in milder cases, results in a reduced sensitivity to phosphates
and, in severe cases, in a strong increase in the baseline. If such ca-
pacity problems occur at one or several positions, the suppressor units
must be treated as follows:
1 Disconnect suppressor from IC system
• Disconnect suppressor from separating column and detector.
2 Regenerate suppressor
• Rinse each suppressor unit for about 15 min with one of the
following solutions:
Contamination with heavy metals
1 mol/L H
2
SO
4
Contamination with organic cationic complexing
agents
0.1 mol/L H
2
SO
4
/ 0.1 mol/L oxalic acid / acetone 5%
Severe contamination with organic substances
0.2 mol/L H
2
SO
4
/ acetone ≥ 20%
The 6.1826.050 pump tubing is made of PVC and must
not be used for rinsing with solutions which contain
acetone. In such cases, rinse with different pump tubing
or a different pump.
3 Connect suppressor to IC system
• Reconnect suppressor to the IC system. If capacity problems
persist, replace the suppressor rotor (see section 5.2.8).
Regenerating the suppressor in case of
high counterpressure
If excessive counterpressure is observed in one or several suppressor
units, treat the units as follows:
1 Disconnect suppressor from IC system
• Disconnect suppressor from separating column and detector.