Biotechnology
 
    Filter Papers Quantitative

Filter Papers Quantitative

  • Quantitative analysis
  • Low ash content 0.007% (Acid-wash treated)
  • High wet-strength

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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.

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 94: 1.5μm – Slow Speed
    This is an extremely fine retention filter for critical gravimetric analysis of very fine particles such as barium and lead sulfates, stannic and nickel sulfide, calcium oxalate and calcium fluoride.
     
  • Ahlstrom 74: 2.0μm – Medium Speed
    This grade has medium flow rate and good particle retention and is the most commonly used acidwashed filter. Ahlstrom 74 covers a wide range of general ashless filtration applications. It is used for gravimetric analysis of numerous components (e.g.: cements, copper, clay, bismuth, silicon, iron) found in heavy industries such as construction, mining or steel. Ahlstrom 74 is also used as a high purity filter for speedy filtering of trace elements such as silver chromate, lead sulfate, zinc and ammonium hydroxides. Ahlstrom 74 is also found in general soil analysis for separating solid from aqueous extracts.
     
  • 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.

 

Hardened Ashless Grades (Ash 0.006%)
These specially treated hardened ashless grades are available for critical quantitative analytical techniques requiring increased wet-strength and handling capacity. These high purity filter papers have a tough, smooth surface free of loose fibers and are ideal for collecting wet precipitates. Each grade offers a convenient combination of particle retention and flow rate and are generally used because of their high chemical resistance to strong acid and alkali.
  • Ahlstrom 95: 1.5μm – Slow Speed
    This is an extremely fine retention filter for critical gravimetric analysis and metal determination of very fine particles such as barium and lead sulfates, stannic and nickel sulfide, calcium oxalate and calcium fluoride.
     
  • Ahlstrom 75: 2.0μm – Medium Speed
    This grade has medium flow rate and good particle retention and is most commonly used for applications requiring high chemical resistance to strong acid and alkali. Ahlstrom 75 is often used for filtering trace elements, collecting hydroxides after precipitation by strong alkalis and in the analysis of metals in acid and alkali solutions.
     
  • Ahlstrom 55: 15μm – Fast Speed
    This is a fast filtering grade for gravimetric analysis of coarse particles and gelatinous precipitates (i.e.: aluminum and zirconium hydroxides) in acid and alkali solutions. Ahlstrom 55 is also used in air and foodstuffs analysis and for chloride and phosphorous in cement, coal and coke.

 

Typical Grade Properties
GradesRetention in µmFiltration Speed
Herzberg sec/100mls		Filtration Speed
Rapidity mls/min		Loading
capacity		Whatman Cross
Reference
941.517244Medium42
742.022930Medium40
5410.034200Medium41
951.545815Medium542 and 50
752.014945Medium540 and 52
5515.031220Medium541 and 54

 

Catalog Numbers
(100 circles/box)
Size*545574759495
4.250540-04250550-04250740-04250750-04250940-04250950-0425
5.50540-05500550-05500740-05500750-05500940-05500950-0550
7.00540-07000550-07000740-07000750-07000940-07000950-0700
9.00540-09000550-09000740-09000750-09000940-09000950-0900
11.00540-11000550-11000740-11000750-11000940-11000950-1100
12.50540-12500550-12500740-12500750-12500940-12500950-1250
15.00540-15000550-15000740-15000750-15000940-15000950-1500
18.50540-18500550-18500740-18500750-18500940-18500950-1850
24.00540-24000550-24000740-24000750-24000940-24000950-2400
27.00540-27000550-27000740-27000750-27000940-27000950-2700
32.00540-32000550-32000740-32000750-32000940-32000950-3200
40.00540-40000550-40000740-40000750-40000940-40000950-4000
* All circle diameters are in centimeters