Grade 40:8 um.The classic general purpose ashless filter paper with medium speed and retention.Typical application 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 solution prior to AA spectrometry. Used also as a high-purity filter in the collection of trace elements and radionuclides from the atmosphere https://www.newstarsciences.com/...lter-paper-grade-40.html