Qualitative Filter Papers-Grade 6: 3μm

Grade 41: 20 μm*
The fastest ashless filter paper, recommended for analytical procedures involving coarse particles or gelatinous precipitates (e.g. iron or aluminum hydroxides).

Also used in quantitative air pollution analysis as a paper tape for impregnation when
determining gaseous compounds at high flow rates.

Grade 40: 8 μm*

The classic general purpose ashless filter paper with medium speed and retention.

Typical applications include gravimetric analysis for numerous components in cements,clays, iron, and steel products; as a primary filter for separating solid matter from aqueous extracts in general soil analysis; quantitative determination of sediments in milk, and as a pure analytical grade clean-up filter for solutions prior to AA
spectrometry.

Also used as a high-purity filter in the collection of trace elements and radionuclides from the atmosphere.