Whatman Grade 41 filters are suitable for quantitative air pollution analysis as a paper tape for impregnation when determining gaseous compounds at high flow rates. Grade 41 filters are also commonly used in preparing solid environmental samples (e.g., soils, sludges) for metals analysis after nitric acid digestion. Grade 41 is available in a convenient, disposable, 47 mm filter funnel with a 250 ml capacity. The 47 mm diameter filter can be easily removed for further analysis or culturing. Whatman Product Code 1442-110 Material Cotton Filter Media Cellulose Grade 41 Size 110 mm Diameter Typical Particle Retention in Liquid 20 µm Thickness 215 µm Basis Weight 85 g/m^2 Ash Content ≤0.007% Air Flow Rate 4 s/100 mL/in^2 Water Flow Rate 254 ml/min Alpha Cellulose Content ≥98% Format Circles Pack Size 100