Whatman 1442-185 Filter Circles, 185mm Dia, Ashless Grade 42, 100/pk (PN:1442-185)

Grade 42 filter paper is designed for high-precision laboratory filtration, especially in gravimetric analysis and sample preparation for instrumental testing. It is commonly used when extremely low contamination and accurate measurement results are required.

This grade provides very fine particle retention of approximately 2.5 µm, making it ideal for capturing fine precipitates such as barium sulfate or calcium carbonate during analytical procedures.

Ashless filter paper is specially manufactured to contain extremely low ash content (≤0.007%), ensuring minimal residue after burning. This is critical in gravimetric analysis where any residue could affect final weight measurements and accuracy.

Grade 42 is classified as a slow filtration paper, allowing for maximum retention of very fine particles. While filtration may take longer, it ensures high accuracy and clean separation, which is essential for analytical applications.

The 185 mm diameter provides a larger filtration area, making it suitable for medium-to-high volume sample processing in laboratory and industrial environments. It helps improve efficiency by reducing the need for multiple filters.