Minipore quantitative filters are designed for gravimetric analysis and the preparation of samples for instrumental analysis.
Grade : 40M
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.

Grade : 41M
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 : 42M
A world standard for critical gravimetric analysis with the finest particle retention. Typical analysis precipitates include barium
sulfate, metastannic acid and finely precipitated calcium carbonate.