GE AKTA avant User Manual page 308

7 Maintenance
7.6 Maintenance when required
7.6.7 Clean the pH electrode
Oil or grease films
Wash the electrode tip in liquid detergent and water. If the films are known to be soluble
in a particular organic solvent, wash with this solvent. Rinse the electrode tip in distilled
water.
Protein deposits
Dissolve the deposit by immersing the electrode in a solution of 1% pepsin in 0.1 M HCl
for five minutes, followed by thorough rinsing with distilled water.
If these procedures fail to rejuvenate the electrode, try the following procedure.
Note:
Step
1
2
3
If these steps fail to improve the electrode, replace the electrode, see Section 7.5.2 Replace
the pH electrode, on page 286.
308
This procedure can be performed only when the pH electrode is not installed
in the pH valve.
Action
Heat a 1 M KNO solution to 60°C–80°C.
3
Place the electrode tip in the heated KNO
Allow the electrode to cool while immersed in the KNO
testing.
solution.
3
solution before re-
3
ÄKTA avant User Manual 29035184 AE