Metrohm 761 SD Compact IC - Manual (Page 106)

6 Notes – Maintenance – Faults
761 SD Compact IC / Instructions for Use 8. 761.1043
98
6.2.6 Regeneration of the suppressor module
Regeneration of 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 (100 mmol/L
H
2
SO
4
) normally used. This diminishes the capacity of the suppressor
units which, in milder cases, results in a reduced sensitivity to phos-
phates and, in severe cases, results in a strong increase in the baseline
and/or pressure rise. If such capacity problems occur at one or several
positions, the corresponding suppressor units must be treated as fol-
lows:
1 Disconnect the suppressor from the IC system
• Disconnect the suppressor from the separating column and
detector.
2 Regenerate the suppressor
• Rinse each suppressor unit for approx. 15 minutes with one
of the following solutions:
Contamination with heavy metals
1 mol/L H
2
SO
4
+ 0.1 mol/L oxalic acid
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 %
3 Connect the suppressor to the IC system
• Reconnect the suppressor to the IC system. If capacity prob-
lems persist, replace the suppressor rotor (see Section 6.2.8).