Whatman

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

Cellulose extraction thimbles are produced from high-quality alpha cellulose cotton
linter and have excellent mechanical strength and retention.
Standard single thickness thimbles have a wall thickness of approximately 1 mm
(10.0 μm nominal particle retention).

Offers fine particle retention and high flow rate, as well as good loading capacity.

Used for high-efficiency general purpose laboratory filtration, including water pollution monitoring of effluents, for filtration of water, algae and bacteria cultures, food stuff analyses, protein filtration, and radioimmunoassay of weak ß emitters.

Recommended for gravimetric determination of airborne particulates, stack sampling, and absorption
methods of air pollution monitoring.

Quantitative filter papers –

Hardened ashless grades
Hardened ashless filter papers are suited for a variety of precipitate sizes.

Along with general filtration
Grade 540, the range includes Grade 542 for retention of fine precipitates and Grade 541 for fast filtration.

All three grades are designed for use in gravimetric analysis.

These filter papers exhibit high wet strength and chemical resistance and are acid hardened, which reduces
ash to an extremely low level. Their tough surfaces make them suitable for a wide range of critical analytical
filtration operations.

Each grade offers a convenient combination of filtration speed and particle retention.

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).

Grade 44: 3 μm*
Thin version of Grade 42 retaining very fine particles but with lower ash weight per sample and almost twice the flow rate of Grade 42.

Grade 41: 20 μm*
The fastest ashless filter paper, recommended for analytical procedures involving coarse particles or gelatinous precipitates (e.g. iron or aluminum hydroxides).

Also used in quantitative air pollution analysis as a paper tape for impregnation when
determining gaseous compounds at high flow rates.

Grade 40: 8 μm*

The classic general purpose ashless filter paper with medium speed and retention.

Typical applications include gravimetric analysis for numerous components in cements,clays, iron, and steel products; as a primary filter for separating solid matter from aqueous extracts in general soil analysis; quantitative determination of sediments in milk, and as a pure analytical grade clean-up filter for solutions prior to AA
spectrometry.

Also used as a high-purity filter in the collection of trace elements and radionuclides from the atmosphere.

Grade 93: 10 μm*
This filter paper is intermediate in speed and retention between Grades 1 and 4.

Available in a dispenser pack, which can be attached to the wall or bench, placed on a
shelf either upright or flat, and used as a normal carton or as a convenient dispenser.

The envelopes are released individually for easy one-at-a-time removal.

Package and envelopes are clearly marked for size and content.

Grade 6: 3 μm*

Twice as fast as Grade 5 with similar fine particle retention.

Often specified for boiler water analysis applications.