Quantitative/Hardened Filter Papers

• Highest quality alpha cotton cellulose
• Ash Content: 0.01%(Except No.4A 0.025%)
• Acid washed: Double acid washed in hydrochloric then hydrofluoric acid (No. 3, 5A, 5B, 5C, 6), then rinsed with ultrapure water to neutralize. No. 4A is further treated with nitric acid before washing

APPLICATIONS
• Gravimetric analysis
• Environmental monitoring

Grade	Comments
No. 3 Ashless	Medium retention (5-10 μm), fast flow rate Analysis of soils, fertilizers, cement, and minerals
No. 5A Ashless	Fast flow rate, retains coarse particulates and gelatinous precipitates (>10 μm). Filter hydroxides and metallic aerosols, environmental monitoring, determine silica content in steel
No. 5B Ashless	Retains medium particles (5-10 μm) such as CaCO3, PbSO4, CaCO4, MnCO3, ZnCO3, ZnS, AgCl
No. 5C Ashless	Collect fine precipitates (<5 μm) such as SrSO4, BaSO4, HgCrO4, and colloidal dispersions; gravimetric analysis
No. 6 Ashless	Retains medium-fine particulates (2-10 μm), trace and precious metals
No. 7 Ashless	Highest purity for retaining medium particles (5-10 μm), precise gravimetric analysis
No. 4A Hardened	High wet strength, suitable for Hardened use under high pressure, high chemical and pH resistance, retains fine crystalline precipitates (<5 μm), slow flow

 For Characteristics and Applications, please click here.