Whatman Grade 1 Qualitative Filter Papers are the most widely used filter paper for routine laboratory applications, qualitative analytical separations, and clarifying liquids. They are the standard grade cellulose filter papers for medium flow rates.

• Qualitative analytical separations for precipitates such as lead sulfate, calcium oxalate (hot), and calcium carbonate
• Agricultural soil analysis and seed testing procedures
• Industrial food processing techniques to extract liquid or separate solid foodstuffs from associated liquid
• Air pollution monitoring by collecting atmospheric dust from airflow and photometrically measuring the stain-intensity
• Gas detection by quantitative chromogenesis with optical reflectance

Grade 1: 11 μm (medium flow filter paper)

• 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.

Laboratory Application

This grade 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.

Agricultural and Food Industry Application

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.

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.