Ahlstrom manufactures a series of extremely high purity, acid washed filter papers designed for use in analytical and gravimetric analysis. The quantitative grades are manufactured from top quality cotton linters using ultra-pure, reverse-osmosis water and are further treated with dilute acid to remove any remaining organic and inorganic impurities. All quantitative grades are manufactured in a strictly controlled environment that ensures high uniformity and high purity from filter to filter. Key Features Quantitative analysis Low ash content 0.007% (Acid-wash treated) High wet-strength Consistent performance Hardened grades available Custom cut Bulk packaging Ashless Grades (Ash 0.007%) These standard ashless grades are high purity filter papers suitable for routine quantitative gravimetric techniques and in the preparation of samples for use in analysis involving instrumental techniques. Ahlstrom 54: 10µm – Fast Speed This is a fast filtering grade for rapid filtration of coarse particles and gelatinous precipitates such as iron, zirconium and aluminum hydroxides, and cobalt sulfide. Ahlstrom 54 is also used in air pollution testing to determine gaseous compounds. It is recommended for fast analysis procedures for unstable precipitates such as silicon, which requires speedy filtration. Mining Laboratory Applications: ASTM D2492-02 Forms of Sulfur in Coal Grade 74 is used during the initial extraction and to determine the percent of pyritic sulfur. Grade 54 and Grade 94 are used to determine the percent of sulfate sulfur. Construction Laboratory Applications: ASTM C114-11b Chemical Analysis of Hydraulic Cement Hydraulic Cement is tested for the presence of multiple elements with this procedure. Quantitative filters, Type II ASTM 832 E, F and G (Ahlstrom Grades 54, 74, and 94 respectively) are recommended for various steps in the process. ASTM C1084-97 Portland-Cement Content of Hardened Hydraulic-Cement Concrete This test method provides two ways to identify the percent of Portland cement within hardened hydrauliccement concrete. The oxide analysis procedure calls for Grade 94 and the Maleic Acid Extraction procedure calls for Grade 54. ASTM D806-96 Cement Content of Soil/Cement Mixtures The cement content of a dry soil/ cement mixture is determined with this procedure. There are several steps, all of which require filter paper. The first extraction is done with Hydrochloric acid; Grade 601 is recommended. The filtrate is precipitated and filtered with Grade 54. Again the filtrate is treated and re-filtered with Grade 601. The final precipitate step is filtered with Grade 94.