Ahlstrom-Munksjö’s qualitative grades of filter paper are recommended for use in analytical methods which determine or identify particulate constituents of a mixture irrespective of the amount present. Qualitative filter papers are often used in routine separation work that still requires high purity and consistent performance. These filter papers covers a wide range of laboratory applications, as liquids clarification, qualitative analytical separations for precipitates and buffers filtration, and are also used for soil analysis and in food and beverage testing. Wet-strengthened grades contain a reinforcement agent that increases their resistance to rupture when wet, such as in vacuum filtration, and their resistance when filtering acidic solutions.
Grade 5 and V5: Very fast filtering, open fiber matrix. For coarse and voluminous precipitates such as iron- aluminum- and chromium hydroxide; Si- determination in steel and pig iron analysis.
Grade 3: Fast filtering, open fiber matrix. For coarse and voluminous precipitates such as iron- aluminum- and chromium hydroxide; Si- determination in steel and pig iron analysis.
Grade V150: Medium fast filtering, open to medium fiber matrix. For qualitative tasks, coarser precipitates such as lead-, iron- and silver sulfide; alkali carbonates; calcium oxalate.
Grade 1F and V1F: Medium to slowly filtering, medium tight fiber matrix. For fast filtration of fine precipitates such as calcium oxalate, magnesium ammonium phosphate, coarser forms of barium sulphate.
Grade Munktell no. 1 and 292: Medium to slowly filtering, medium tight fiber matrix. For fast filtration of fine precipitates such as calcium oxalate, magnesium ammonium phosphate, coarser forms of barium sulfate.
Grade Munktell no. 2 and 292a: Slowly filtering, tight fiber matrix. For filtration of fine precipitates such as lead dioxide, calcium fluoride, nickel sulfide, zinc sulfide.
Grade 106: Slowly filtering for fine precipitates such as lead dioxide, calcium fluoride, nickel sulphide and zinc sulphide.
Grade 120H and V120H: Very slowly filtering, tight fiber matrix. For fine precipitates such as barium sulphate, metastannic acid and cuprous oxide.