Metrohm 833 IC Liquid Handling Unit - Manual (Page 97)

9.2 Care and maintenance
830 IC Interface / Gebrauchsanweisung 8.830.1001
89
9.2.7.1 Replacing the dialysis membrane
It may be necessary to replace the dialysis membrane in the following
circumstances (see also Section 9.1):
• Reduced yield after dialysis
• Membrane damaged by drying out or deposits or
bacterial growth
• Irreparable blockage of sample channel (sample can
no longer be transported through dialysis cell)
Proceed as follows when replacing the membrane (see Fig. 15):
1 Dismantle dialysis cell
• Screw off the four inlets and outlets of dialysis cell 42 and
take the cell out of the cell holder.
• Use the 6.2621.070 Allen key to loosen the 5 screws 47 and
separate lower part 46 from upper part 43
• Remove old dialysis membrane 45.
2 Clean dialysis cell, insert dialysis membrane and
reassemble cell
• See Steps 2-6 Section 7.4 Assembling the dialysis cell.
3 Connect dialysis cell
• See dialysis cell Section 7.5.2 Connection of the dialysis
cell.
4 Condition dialysis membrane
See also Section 7.5.2.
• Immerse the 2 pieces of aspiration tubing 16 (see Fig. 21) in
the acceptor solution (degassed ultrapure water).
• Switch on the peristaltic pump in «IC Net».
• Rinse the dialysis system for approx. 20 min with ultrapure
water. Check that the same amount of solution emerges from
both the waste outlets in the waste bottle.
• Check all tubing from the storage containers to the tubing
cassettes and dialysis cell and up to the waste bottle for
leaks. If any leaks are found then the corresponding
connection must either be tightened up or replaced.
• If any air bubbles remain in the dialysis cell then screw off
PEEK tubing 61 (acceptor solution) and PTFE tubing 58
(sample) from outlets 49 and 52 of the dialysis cell and wait
until the air bubbles have vanished. Then screw the tubing
back on again.
• Switch off peristaltic pump.