Whatman No. 541

Should be used for gelatinous precipitates and coarse particles. Filtering is very fast: initial filtration speed is approx. 12 seconds. Loading capacity is normal. Retention rating is 20-25 µm. High strength when wet. Chemically resistant. Used extensively for filtering gelatinous precipitates from alkaline solutions, and filtering of metallic hydroxides. Under strongly acidic or alkaline conditions, this paper is useful in intermediate stages of gravimetric analysis. Ash content is 0.08 mg per 12.5 cm circle. (For cost savings, see Ahlstrom equivalent, 445-300-02 Series)