No 42 (MN-640 d)

Whatman No 42 / andMacherey-Nagel 640 d

Quantitative Filter Papers

Ashless filter papers for quantitative analysis.and

Smooth, slow filtration.

Thickness 0.17 mm

Filtration speed 140 s

Basic weight 85g/m2

Extremely Low Ash Content (<0.01%)and

An ash-less filter with a slow filtering rate and high retention of small particles and fine precipitates, such as cold barium sulphate, lead sulphate, zinc and nickel sulphides, etc. Recommended for critical gravimetric analysis. Widely used for precipitates with tendencies toward colloidal dispersion. Suitable for gravity or low suction filtrationand It is also recommended for testing for insoluble impurities in oils and fats of animal or vegetable origin.

Ashless filter papers are particularly suited for quantitative routine analysis and are manufactured from refined pulp and linters. They are acid-washed and have an extremely low ash content of < 0.01 %. The amount of α-cellulose is about 95 %and