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Optimizing Performance
Prevent Blocking of Solvent Filters
Prevent Blocking of Solvent Filters
Contaminated solvents or algae growth in the solvent bottle will reduce the
lifetime of the solvent filter and will influence the performance of the pump.
This is especially true for aqueous solvents or phosphate buffers (pH 4 to 7).
The following suggestions will prolong lifetime of the solvent filter and will
maintain the performance of the pump:
• Use sterile, if possible amber, solvent bottles to slow down algae growth.
• Filter solvents through filters or membranes that remove algae.
• Exchange solvents every two days or refilter.
• If the application permits add 0.0001–0.001 M sodium azide to the solvent.
• Place a layer of argon on top of your solvent.
• Avoid exposure of the solvent bottles to direct sunlight.
Checking the Solvent Filters
The solvent filters are on the low-pressure side of the pumping system. A
blocked filter therefore does not affect the pressure readings of the pump.
The pressure readings cannot be used to identify blocked filters. If the
solvent cabinet is placed on top of the vacuum degasser the filter condition
can be checked in the following way:
Remove the tubing at the inlet port of the vacuum degasser. If the filter is in
good condition the solvent will freely drip out of the solvent tube (due to
hydrostatic pressure). If the solvent filter is partly blocked no solvent or only
very little solvent will drip out of the solvent tube.
Cleaning the Solvent Filters
• Remove the blocked solvent filter from the bottle-head assembly and place
it in a beaker with concentrated nitric acid (35%) for one hour.
• Thoroughly flush the filter with bidistilled water (remove all nitric acid,
some capillary columns can be damaged by nitric acid).
• Replace the filter.
NOTE Never use the system without solvent filter installed.