Extremely low ash content (0.007% ash maximum) 20 µm nominal particle retention rating Fast filtration speed (Herzberg 54 s) Commonly used for routine air pollution analysis and soil pollution analysis Whatman Grade 41 environmental pollution papers are among the fastest filter papers in the Whatman ashless range. This gravimetric filter is well suited for quantitative analysis of soil and air. Aside from Grade 41 environmental pollution papers, Whatman quantitative paper comes in a variety of particle retentions, filtration speeds, and filter thicknesses to provide you with the appropriate filter for your precipitate. Also see our hardened ashless grades for analysis requiring the use of strong acids or bases.
