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58545-N47
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How To Condition 47mm Nylon Membranes for Use with the Mobile Phase Filter Degasser...
Filter membranes with smaller pores sizes such as 0.45µm have higher bubble points
(the differential pressure required to draw air through a wet membrane). The bubble point is a function of the
pore size and the surface tension and viscosity of the solvent wetting the membrane. With aqueous solvents a
vacuum cannot always overcome the bubble point.
- Use an initially dry membrane and filter the entire required volume without breaking the vacuum. If this does
not work...
- Remove the siphon tube from its assembly and fill the reservoir above the filter with approximately 25ml of
the liquid to be filtered, reattach the siphon tube, re-immerse it in the solvent to be filtered and apply
the vacuum. If this does not work, use a greater vacuum or a large pore size membrane.
Please note that unstirred and unsparged organic solvents such as methanol and acetonitrile become re-equilibrated
with ambient gasses in a few hours while aqueous solutions require approximately 10 hours to re-equilibrate. Use a
helium sparging device to keep your solvents degassed.
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