Filter Papers Quantitative

Ahlstrom - Ashless

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

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Description

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
Grades	Retention in µm	Filtration Speed Herzberg sec/100mls	Filtration Speed Rapidity mls/min	Loading capacity	Whatman Cross Reference
94	1.5	1724	4	Medium	42
74	2.0	229	30	Medium	40
54	10.0	34	200	Medium	41
95	1.5	458	15	Medium	542 and 50
75	2.0	149	45	Medium	540 and 52
55	15.0	31	220	Medium	541 and 54

Catalog Numbers
(100 circles/box)
Size*	54	55	74	75	94	95
4.25	0540-0425	0550-0425	0740-0425	0750-0425	0940-0425	0950-0425
5.5	0540-0550	0550-0550	0740-0550	0750-0550	0940-0550	0950-0550
7.0	0540-0700	0550-0700	0740-0700	0750-0700	0940-0700	0950-0700
9.0	0540-0900	0550-0900	0740-0900	0750-0900	0940-0900	0950-0900
11.0	0540-1100	0550-1100	0740-1100	0750-1100	0940-1100	0950-1100
12.5	0540-1250	0550-1250	0740-1250	0750-1250	0940-1250	0950-1250
15.0	0540-1500	0550-1500	0740-1500	0750-1500	0940-1500	0950-1500
18.5	0540-1850	0550-1850	0740-1850	0750-1850	0940-1850	0950-1850
24.0	0540-2400	0550-2400	0740-2400	0750-2400	0940-2400	0950-2400
27.0	0540-2700	0550-2700	0740-2700	0750-2700	0940-2700	0950-2700
32.0	0540-3200	0550-3200	0740-3200	0750-3200	0940-3200	0950-3200
40.0	0540-4000	0550-4000	0740-4000	0750-4000	0940-4000	0950-4000
* All circle diameters are in centimeters