Quantitative Filter Papers-Grade 42: 2.5μm

Whatman quantitative filters are designed for gravimetric analysis and the preparation of samples for instrument
analysis. They are available in three formats designed for specific requirements.

• Ashless: 0.007% ash nominal for Grades 40 to 44 and a typical of 0.01% for the 589 Grades – very pure
filters suitable for a wide range of critical analytical filtration procedures.
• Hardened low ash: 0.015% ash nominal – treated with a strong acid to remove trace metals and produce
high wet strength and chemical resistance. These filters are particularly suitable for Büchner filtration where
the tough, smooth surface of the filter makes it easy to recover precipitates.
• Hardened ashless: 0.005% ash nominal – acid hardened to give high wet strength and chemical resistance
with extremely low ash content. The tough surface makes these filters suitable for a wide range of critical
filtration procedures.