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

• Gravimetric analysis
• Environmental monitoring

Grade Comments
No. 3
Medium retention (5-10 μm), fast flow rate Analysis of soils, fertilizers, cement, and minerals
No. 5A
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
Retains medium particles (5-10 μm) such as CaCO3, PbSO4, CaCO4, MnCO3, ZnCO3, ZnS, AgCl
No. 5C
Collect fine precipitates (<5 μm) such as SrSO4, BaSO4, HgCrO4, and colloidal dispersions; gravimetric analysis
No. 6
Retains medium-fine particulates (2-10 μm), trace and precious metals
No. 7
Highest purity for retaining medium particles (5-10 μm), precise gravimetric analysis
No. 4A
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.