Whatman Filter Paper - Grade 1 Circles
These cellulose filters are used in qualitative analytical techniques to determine and identify materials. Prepleated qualitative filters are also available, which give improved flow rate and increased loading capacity compared to equivalent flat filters.
Grade 1 (11 µm)
The most widely used filter paper for routine applications with medium retention and flow rate. Extended range of sizes includes 10 to 500 mm diameter circles and 460 x 570 mm sheets. This filter is also available in theFilterCup, this is a convenient, disposable 70 mm filter funnel with a 250 ml capacity molded from polypropylene with an integral, heat bonded filter (catalog number 1600-001).
This grade covers a wide range of laboratory applications and is frequently used for clarifying liquids. Traditionally the grade is used in qualitative analytical separations for precipitates such as lead sulfate, calcium oxalate (hot), and calcium carbonate.
In agriculture, it is used for soil analysis and seed testing procedures. In the food industry, Grade 1 is used for numerous routine techniques to separate solid foodstuffs from associated liquid or extracting liquid and is widely used in education for teaching simple qualitative analytical separations.
In air pollution monitoring, using circles or rolls, atmospheric dust is collected from airflow and the stain-intensity measured photometrically. For gas detection, the paper is impregnated with a chromogenic reagent and color formation quantified by optical reflectance.
Available In The Following Sizes
Diameter P/Box
18 mm 100
20 mm 100
25 mm 100
30 mm 100
42.5 mm 100
47 mm 100
55 mm 100
70 mm 100
85 mm 100
90 mm 100
110 mm 100
125 mm 100
150 mm 100
185 mm 100
240 mm 100
270 mm 100
320 mm 100
400 mm 100
500 mm 100


Due to the continuous development of our products, the goods supplied may vary in detail to that illustrated on our website.