WHA1444070
Whatman® quantitative filter paper, ashless, Grade 44
circles, diam. 70 mm, pack of 100
Synonym(s):
Z241164
About This Item
material
circles
cotton filters (high-quality cotton linters)
packaging
pack of 100
manufacturer/tradename
Whatman 1444-070
Whatman Article No. 28418063 (US reference)
parameter
0.29 psi wet burst
995 sec/100 mL speed (Herzberg)
diam.
70 mm
thickness
180 μm
ash
≤0.007%
pore size
3 μm (Particle retention)
basis weight
80 g/m2
Looking for similar products? Visit Product Comparison Guide
General description
Ashless: 0.007% ash maximum for Grades 40 to 44 and a maximum of 0.01% for the 589 Grades - very pure filters suitable for a wide range of critical analytical filtration procedures.
Hardened low ash: 0.015% ash maximum - treated with a strong acid to remove trace metals and produce high wet strength and chemical resistance. These filters are particularly suitable for Büchner filtration where the tough smooth surface of the filter makes it easy to recover precipitates.
Hardened ashless: 0.006% ash maximum - acid hardened to give high wet strength and chemical resistance with extremely low ash content. The tough surface makes these filters suitable for a wide range of critical filtration procedures.
Grade 44: 3 μm (slow to medium filter paper)
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.
Features and Benefits
- Accurate ash free dry mass measurements
- Fine nominal particle retention rating of 3 µm
- filtration speed (Herzberg 995 s)
- Typical thickness of 180 µm
Other Notes
Legal Information
Certificates of Analysis (COA)
Search for Certificates of Analysis (COA) by entering the products Lot/Batch Number. Lot and Batch Numbers can be found on a product’s label following the words ‘Lot’ or ‘Batch’.
Already Own This Product?
Find documentation for the products that you have recently purchased in the Document Library.
Our team of scientists has experience in all areas of research including Life Science, Material Science, Chemical Synthesis, Chromatography, Analytical and many others.
Contact Technical Service