Advantec Quantitative Ashless Filter Papers are made from the highest quality alpha cotton cellulose.
Grade No.3 Medium retention, fast flow rate paper with good chemical resistance and wet strength. Recommended for analysis of soils, fertilizers, cement, and minerals. Grade No.5A Retain coarse and gelatinous ppt with high flow rates. Filter hydroxides, metalic aerosols, environmetnal monitoring, and determine silica content in steel. Grade No.5B Retain medium size ppt such as CaCo₃, PbSO₄, AgCl. General purpose paper. Grade No.5C High retention efficiency collecting fine ppt with slow flow rate. Gravimetric analysis and collecting particles that tend toward colloidal dispersion. Grade No.6 Retains medium-fine particulates. Uses are precision analysis of trace and precious metals, beverages, water. Grade No.7 Highest purity paper for medium particles. Fast flow rate. Recommended for precise gravimetric analysis of minute trace and precious metals. Grade No.4A Hardened, smooth low ash paper with superior wet strength. Retains fine crystalline ppt with slow flow rate. Suitable for Buchner filtrations, high pressure, high chemical and pH resistance.
One critical step in the manufacture of these filter papers is acid washing. All grades are double acid washed in hydrochloric then hydrofluoric acid to reduce levels of SiO₂, CaO, and Fe2O₃. Grade No.4A Hardened is further treated with nitric acid. Following the acid wash, all papers are rinsed in ultrapure water to neutralize. Ash Content: 0.01% (except No.4A 0.025%).
Ordering information: Various sizes up to 50.0 cm available.