Whatman 1440-012 Filter Circles, 12.7mm Dia, Ashless Grade 40, 400/pk (PN:1440-012)

Whatman Grade 40 ashless filter paper is widely used in quantitative laboratory analysis, particularly for gravimetric procedures where accurate mass measurements are required. It is commonly applied in soil analysis, cement and metal testing, and other analytical processes that require very low background contamination from the filter material.

Grade 40 filter paper provides medium particle retention of approximately 8 µm, allowing it to capture small suspended solids while maintaining a balanced filtration speed. This makes it suitable for many analytical and sample preparation tasks in chemistry and environmental laboratories.

Ashless filter paper contains very low residual ash content (around 0.007%). When the paper is burned during gravimetric analysis, it leaves almost no residue, preventing contamination or measurement errors in the final mass of the analyzed sample.

This grade is frequently used for soil extracts, cement and clay testing, milk sediment analysis, and trace element collection. Its purity and reliable filtration performance make it suitable for a wide range of analytical laboratory procedures.

The 12.7 mm diameter filter circles are typically used in small laboratory filtration devices such as micro filtration holders, sample preparation units, and specialized analytical filtration assemblies designed for small sample volumes.