Whatman Filter Paper - Grade 40 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 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.

 

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

 

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