Advantec Quantitative Ashless Filter Papers are made from the highest quality alpha cotton cellulose. One critical step in the manufacturing process 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. Following the acid wash, all papers are rinsed in ultrapure water to neutralize. 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 Grade No. 4A is 0.025%).
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. Nominal Retention: 5 µm.
Grade No. 5A
Retains coarse and gelatinous ppt with high flow rates. Filter hydroxides, metalic aerosols, environmetnal monitoring, and determine silica content in steel. Nominal Retention: 7 µm.
Grade No. 5B
Retains medium size ppt such as CaCo3, PbSO4, AgCl. General purpose paper. Nominal Retention: 4 µm.
Grade No. 5C
High retention efficiency collecting fine ppt such as BaSO4 with slow flow rate. Gravimetric analysis and collecting particles that tend toward colloidal dispersion. Nominal Retention: 1 µm.
Grade No. 6
Retains medium-fine particulates. Use for precision analysis of trace and precious metals, beverages, water. Nominal Retention: 3 µm.
Grade No. 7
Highest purity paper for medium particulates. Fast flow rate. Recommended for precise gravimetric analysis of minute trace and precious metals. Nominal Retention: 4 µm.
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. Nominal Retention: 1 µm.
Please Note: ALL Advantec items have a maximum 48 hour cancellation window. Any cancellations AFTER the 48 hour window will incur a restocking fee equal to the cost of the product.