Whatman 1441-090 Filter Circles, 90mm Dia, Ashless Grade 41, 100/pk (PN:1441-090)

Whatman Grade 41 filter papers are commonly used in quantitative laboratory analysis, especially for applications involving soil, environmental, and air pollution testing. They are often used in gravimetric procedures where accurate filtration and minimal residue are critical.

This filter paper provides particle retention of approximately 20–25 µm, making it suitable for filtering relatively coarse particles while maintaining fast filtration speed in routine laboratory workflows.

Ashless filter paper contains extremely low mineral residue—typically no more than about 0.007% ash content—so it can be incinerated during gravimetric analysis without leaving significant residue that could affect measurement accuracy.

Grade 41 is considered one of the fastest filtration papers in the ashless quantitative range, allowing laboratories to process samples quickly while still maintaining the purity required for precise analytical work.

The 90 mm filter diameter is designed for use with standard laboratory filtration funnels and gravity filtration setups. The larger filtration surface allows laboratories to process moderate sample volumes efficiently during analytical procedures.