Whatman 1444-150 Filter Circles, 150mm Dia, Ashless Grade 44, 100/pk (PN:1444-150)

These filter papers are designed for quantitative analysis and gravimetric testing, where accurate measurement of residues is critical. They are commonly used in applications such as metal analysis, environmental testing, and chemical sample preparation.

“Ashless” means the paper leaves extremely low residue (≤0.007% ash) after ignition, ensuring that the filter itself does not interfere with analytical results. This makes it ideal for precise laboratory measurements.

Grade 44 offers fine particle retention around 3 µm with a slow to medium filtration rate, allowing effective capture of fine precipitates while maintaining reasonable processing time.

Grade 44 is a thinner version of Grade 42, providing similar fine retention but with lower ash content and faster filtration speed, making it more efficient for gravimetric workflows.

The filter is made from high-quality cotton linters (cellulose fibers), offering consistent performance, chemical compatibility, and reliability for analytical filtration procedures.