Amersham Pharmacia Biotech AKTA design pH/C-900, User Manual

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4 Maintenance
4.1 Periodic maintenance
Interval Action (see procedures below)
Every 6 month Change pH electrode
or more often if required
When required Clean the conductivity cell
Clean the pH electrode
4.2 Cleaning the flow cell
Remove the pH electrode and install the dummy electrode in the pH
flow cell.
Pump a cleaning or sanitizing agent through the flow cells. The
standard recommendation is to pump 1 M NaOH for 30 minutes
and then wash out with buffer.
4.3 Cleaning the pH electrode
Note: The pH electrode has a limited life length and should be
replaced every six months or when the response time is slow.
Use one of the following procedures to clean the electrode to
improve the response:
• Salt deposits: Dissolve the deposit by immersing the electrode first
in 0.1 M HCl, then in 0.1 M NaOH, and again in 0.1 M HCl.
Each immersion is for a 5 minute period. Rinse electrode tip in
distilled water between each solution.
• Oil or Grease Films: Wash electrode tip in a liquid detergent and
water. If film is known to be soluble in a particular organic
solvent, wash with this solvent. Rinse electrode tip in distilled
water.
• Protein deposits: Dissolve the deposit by immersing the electrode
in a 1% pepsin solution, in 0.1 M HCl, for five minutes,
followed by thorough rinsing with distilled water.
Monitor pH/C-900
User Manual 18-1120-06 Edition AC
13
Maintenance
4
WARNING! Disconnect the power supply before attempting to
replace any item on the instrument during maintenance.
CAUTION! Only spare parts approved or supplied by Amersham
Pharmacia Biotech may be used for maintaining and servicing the
instrument.
WARNING! NaOH is injurious to health. Avoid spillage.
18-1120-06_AC.qxd 1999-04-14 14:16 Sida 13 (1,1)