Whatman 1450-090 Filter Circles, 90mm Dia, Hardened Low Ash Grade 50, 100/pk (PN:1450-090)

Whatman Grade 50 filter paper is designed for quantitative laboratory filtration where very fine precipitates must be retained and recovered accurately. It is commonly used in analytical chemistry, environmental testing, and materials research where precise particle separation is required.

This filter paper provides approximately 2.7 µm particle retention, allowing it to capture very fine crystalline precipitates during filtration. Its slow filtration rate improves retention of small particles and helps ensure accurate analytical results.

Hardened low ash filter paper is chemically treated to increase wet strength and reduce fiber shedding, which allows the paper to withstand vacuum filtration and scraping of collected precipitates. Its very low ash content (≤0.015%) ensures minimal residue after combustion, which is essential for accurate gravimetric analysis.

These filter circles are designed for use in gravity filtration or vacuum filtration systems, including setups with Büchner funnels or Hirsch funnels. Their hardened surface helps maintain structural integrity even under vacuum suction conditions.

The Whatman 1450-090 filter paper features a 90 mm diameter circular format, Grade 50 cellulose filter media, approximately 115 µm thickness, and packaging of 100 circles per pack. It is known as the thinnest hardened Whatman filter paper, providing slow filtration and strong retention of very fine particles.