Whatman 1440-090 Filter Circles, 90mm Dia, Ashless Grade 40, 100/pk (PN:1440-090)

Whatman Grade 40 filter paper is a general-purpose quantitative filter used in gravimetric analysis, sample preparation, and analytical filtration. It is commonly applied in testing soils, metals, cement, milk sediments, and environmental samples where high purity is required.

Grade 40 provides approximately 8 µm particle retention with a medium filtration speed, making it suitable for capturing moderately fine particles while maintaining efficient flow rates in routine lab work.

Ashless filter paper contains extremely low ash content (≤0.007%), ensuring minimal residue after burning. This is critical for accurate gravimetric analysis and trace element testing, where contamination could affect measurement results.

The 90 mm diameter is a widely used standard size that fits most laboratory funnels, offering consistent filtration performance and ease of handling for routine analytical workflows and sample preparation tasks.

This filter paper is produced from high-purity cotton linters (alpha cellulose), which provide excellent consistency, chemical compatibility, and reliable filtration performance across a wide range of laboratory applications.