Qualitative Filter Paper

Whatman Grade 2 filter paper is slightly more retentive than Grade 1 with a corresponding increase in filtration time (i.e., slightly slower filtration speed). More absorbent than Grade 1. In addition to general filtration in the 8 µm particle size range, the extra absorbency is utilized, for example, to hold soil nutrient in plant growth trials. Also used for monitoring...

Whatman Grade 4 offers extremely fast filtering (20-25 µm) with excellent retention of coarse particles and gelatinous precipitates such as ferric hydroxide and aluminum hydroxide. Very useful as a rapid filter for routine cleanup of biological fluids or organic extracts during analysis. Used when high flow rates in air pollution monitoring are required and the collection...

Whatman Grade 6 filter paper is twice as fast as Grade 5 with similar fine particle retention (3 µm). Often specified for boiler water analysis applications. 100/box.

Whatman Grade 114 is a wet strengthed qualitative filter paper. Only half the thickness of No. 113 and suitable for coarse or gelatinous precipitates with a retention of 25 µm. Smooth surface for easy recovery of precipitates. 100 circles/box.

Cytiva-Whatman Grade 113V Fluted Qualitative Filter Papers Wet-Strengthened are creped and folded filter paper, for use with a conical filter funnel, offers fast filtration and high loading capacity for analysis involving coarse particles or gelatinous precipitates. Nominal particle retention rating of 30 µm. Fastest flow rate of any qualitative grade. 100/box.

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Whatman Reeve Angel Grade 201 is a general qualitative filter with relatively slow filtration speed. Retains medium-fine precipitates. Smooth surface and close texture. Widely used in industrial laboratories and students laboratories for routine filtration. The filter is wet-strengthened with a small amount of chemically stable resin to extend the life of the filter and...

Whatman Reeve Angel Grade 230 is a general qualitative filter with creped surface. High filtration speed and high loading capacity. Widely used in industrial laboratories and students laboratories for routine filtration. The filter is wet-strengthened with a small amount of chemically stable resin to extend the life of the filter and improve handling. Normal qualitative...

Ahlstrom 610 covers a wide range of laboratory applications and is used for clarifying liquids and for rapid filtration of coarser precipitates such as lead sulfate, lead chromate, calcium oxalate, calcium carbonate, aluminum phosphate, barium carbonate, and beryllium hydroxide. Grade 601 can be used in soil analysis, seed testing, and in air pollution testing to collect...

This grade is a slow-flowing filter designed to retain fine particles encountered in qualitative analysis. Ahlstrom 610 is widely used for water analysis, biological products,  and fine precipitates such as cold-precipitated barium sulfate. Ahlstrom 610 is also used in Buchner funnels and to clarify cloudy suspensions.

Ahlstrom 909, 3.0 μm Retention, Medium Speed. This medium flow rate qualitative wet-strengthened grade filter paper with very good retention is a tighter version of Ahlstrom 962. This grade has a rough surface and is often used in the food industry for routine tests.

Qualitative wet-strengthened grades are manufactured for applications using filter paper in a...