Qualitative Filter Papers-Grade 4: 20-25μm

Whatman chromatography paper media are made from specially selected cotton cellulose.

They are rigorously quality controlled for characteristics important to the chromatographer and to ensure uniformity within
the grade.

Features and benefits
• Pure cellulose produced entirely from the highest quality cotton linters
with no additives of any kind
• Manufactured and tested specifically for chromatographic techniques –
this ensures the wicking capability and uniformity of capillary action that
are important in chemical separations
• Also widely used in protein and nucleic acid blotting

Grade 50: 2.7 μm*
Retention of very fine crystalline precipitates.

The thinnest of all Whatman filter papers with a slow flow rate, these filters have a hardened and highly glazed surface, which also keeps the paper free from loose surface fibers.

Highly suitable for
qualitative or quantitative filtrations requiring vacuum assistance on Büchner
or 3-piece filter funnels.

Very strong when wet and will withstand wet handling and
precipitate removal by scraping.

In the electronics industry, the virtual absence of
fiber shedding is utilized in carriers for integrated circuits.

This grade is also available in Smear Tab format for wipe testing (e.g. testing of
surfaces for radionuclide contamination).