Whatman Filter Paper - Grade 41 Circles
Whatman quantitative filters are designed for gravimetric analysis and the preparation of samples for instrumental analysis. They are available in three formats designed to meet your specific needs.
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 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. This filter is also available in the disposable filter funnel. This is a convenient, disposable 47 mm filter funnel with a 250 ml capacity. The 47 mm Grade 41 filter can be easily removed for further analysis or culturing.


Available In The Following Sizes
Diameter P/Box
55 mm 100
70 mm 100
90 mm 100
110 mm 100
125 mm 100
150 mm 100
185 mm 100
240 mm 100
320 mm 100


Due to the continuous development of our products, the goods supplied may vary in detail to that illustrated on our website.