Whatman™ Quantitative Cellulose Filter Paper

Grade 541

20-25 µm. A hardened ashless filter that offers high filtration speed for the retention of large particles and gelatinous precipitates in acid or alkaline solutions. Typical applications include protein determinations, cement analysis and the determination of fiber in animal food.

Grade 542

2.7 µm. A hardened ashless that gives efficient retention of small particles in solutions that would weaken conventional filters. Slow flow rate. Very hard and strong with excellent chemical resistance. Often used in gravimetric metal determinations.

Grade 40

8 µm. General purpose ashless filter with medium speed and particle retention. Applications include gravimetric analysis, the filtration of solutions prior to atomic absorption spectrophotometry and air pollution monitoring.

Grade 41

20-25 µm. The fastest ashless filter is recommended for analytical procedures involving large particles or gelatinous precipitates such as iron or aluminum hydroxides. Also used in quantitative air pollution analysis for determining gaseous compounds at high flow rates.

Grade 42

2.5 µm . Ashless filter with the finest particle retention of all Whatman cellulose filters. Typical analytical precipitates include barium sulfate, metastannic acid and finely precipitated calcium carbonate.

Grade 43

16 µm. A moderately fast ashless filter used for foodstuff analysis, soil analysis, particle collection in air pollution monitoring and inorganic analysis in the construction, mining and steel industries.

Grade 44

3.0 µm. Ashless filter that gives the lowest ash weight for any given disc size. Slightly less efficient for collecting small particles than Grade 42 but has a higher flow rate.

Grade 50

2.7 µm. The thinnest hardened low ash filter with a slow flow rate and good particle retention characteristics. The hardened surface is virtually free from loose fibers. In the electronics industry, the virtual absence of fiber shedding is utilized in carriers for integrated circuits.

Grade 52

7 µm. A general purpose hardened low ash filter with medium retention and flow rate. Ideal for use with Büchner funnels or Whatman 3-piece filter funnels.

Grade 54

20-25 µm. Hardened low ash filter with very fast filtration for use with coarse and gelatinous precipitates. High wet strength is suitable for vacuum-assisted fast filtration of difficult materials.

Grade 540

8 µm. A general-purpose hardened ashless filter with medium retention and flow rate. Frequently used in gravimetric analysis of metals in acid/alkali solutions.