Whatman Grade 1 Quantitative Filter Papers
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 Qualitative Filter Papers (11 µm particle retention) are available in a variety of sizes and formats including circles, sheets and prepleated filters. They are also available in FilterCup format, a convenient, 250 ml capacity disposable 70 mm filter funnel molded from polypropylene with an integral, heat-bonded filter.
| Grade | Grade 1 |
| Thickness | 180 µm (Typical) |
| Particle retention | 11 µm (Particle retention rating at 98% efficiency), in liquid max. |
| Filtration speed | Approx. 150 s (Herzberg) |
| Ash content | 0.06% |
| Airflow rate | 10.5 s/100 ml/in² |
| Basis weight | 88 g/m² |
| Burst strength | 0.29 psi wet burst; 15.99 dry burst |
| Tensile strength | 39.1 N/15 mm Tensile M/D Dry |