Membrane filters are used with the barrel filter
holder, plate-type in-line filter holder and the in-line
filter holders. These filter membranes are used
primarily for water quality sampling filtration for
trace metals and chemical analysis. The standard filter
membranes are offered in four basic materials.
Cellulose Acetate Membrane recommended
for most analytical filtration applications. Made of
cellulose triacetate and diacetate, they are highly
flexible with a high burst and tensile design strength.
These membranes have the lowest extractable level at
0.1% (by wt.), improved heat resistance, low protein
binding, and are resistant to low molecular weight
alcohols.
Cellulose Nitrate Membrane may be used
in most Cellulose Acetate applications. Made of pure
Cellulose Nitrate, they are typically 80% porous,
allowing for excellent flow rates. They have a slightly
higher extractable level at 3% (by wt.) and are composed
of glycerin and wetting agent.
PTFE Membrane (TEF) are highly
porous and resistant to most acids, bases and chemically
aggressive solvents. They are naturally hydrophobic
making them difficult to use in common filtration of
aqueous solutions.
Glass Fiber Pre-filters are highly
recommended for sediment laden samples to reduce the
particulate loading on the membrane surface. A
pre-filter will greatly extend the life of the membrane.
They are exceptionally pure, containing no binder that
could alter the filtrate. These are also used for
sediment analysis and are listed with our Whatman glass
microfiber filter papers.
TEF Filter Membrane
- Pure TEF TFE
- 10 membranes per package
511-217 Coarse Grade-
20-30 micron maximum pore size, 47 mm diameter by .10 mm
thickness
511-218 Medium Grade- 5-6
micron maximum pore size, 47 mm diameter by .10 mm
thickness
511-219 Fine Grade- 1-2
micron maximum pore size, 47 mm diameter by .25 mm
thickness
511-220 Very Fine Grade-
.45 micron pore size, 47 mm diameter by .07 mm thickness
511-221 Finest Grade- .2
micron pore size, 47 mm diameter by .065 mm thickness
