Whatman No. 4 55mm Filter Paper circles

Whatman Grade 4 Qualitative Filter Papers are a standard grade, high flow rate filter paper. They are useful in qualitative analytical separations when fast flow is required and the collection of fine particles is not critical. These cellulose filters are used in qualitative analytical techniques to determine and identify materials (e.g., in air pollution monitoring). Excellent retention: captures coarse particles and gelatinous precipitates such as ferric hydroxide and aluminum hydroxide Fast filtration: useful for routine clean-up of biological fluids or organic extracts during analysis 20-25µm particle retention