Quantitative Filter Paper, Circle, Grade 391

The quantitative grades are manufactured from top quality cotton linters using ultra-pure, deionized water and are further treated with dilute acid to remove any remaining organic and inorganic impurities. All quantitative grades are manufactured in a strictly controlled environment that ensures high uniformity and high purity from filter to filter.

Hardened Low-Ash grades (Ash 0.01%)
These filters are treated with a strong acid to remove trace metals and produce high wet strength and chemical resistance. They are suitable for routine gravimetric analysis and typical preparation of samples for use in analysis involving instrumental techniques. Particularly, they can be used for Büchner filtration where the tough smooth surface of the filter makes it easy to recover precipitates.