Ahlstrom-Munksjö manufactures a series of extremely high purity, acid washed filter papers designed for use in analytical and gravimetric analysis. The quantitative grades are manufactured from top quality cotton linters using ultra-pure, deionised 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.

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. Hardened Low Ash Grades (Ash 0,001%)

Grade 00H: Very slowly filtering for fine grained precipitates such as barium sulphate, metastannic acid and cuprous oxide.

Grade 006: Slowly filtering for filtration of fine precipitates such as lead dioxide, calcium fluoride, nickel sulphide, zinc sulphide.
Grade 00A: Medium to slowly filtering for fast filtration of fine precipitates such as calcium oxalate, magnesium ammonium phosphate, coarser forms of barium sulphate.

Grade 00K: Medium to slowly filtering, typical grade for quantitative tasks, coarser precipitates such as lead-, iron- and silver sulphide; calcium oxalate.
Grade 00M: Medium to fast filtering, medium wide pores, ashless typical grades for quantitative tasks, coarser precipitates such as lead-, iron- and silver sulphide; alcali carbonates.

Grade 00R: Fast filtering, for coarse and voluminous precipitates such as iron- aluminum- and chromium hydroxide; Si-determination in steel and pig iron analysis.
Grade 005: Very fast filtering, for coarse and voluminous precipitates such as iron- aluminum- and chromium hydroxide; Si-determination in steel and pig iron analysis.