Filter Paper for Air Sampling

Filter Paper for Air Sampling

Environmental air sampling uses two major categories of filter paper media, Cellulose and Glass fiber. Carbon Impregnated filter paper is occasionally called out for in the determination of the presence of airborne Iodine.

GLASS FIBER FILTER MEDIA

Glass fiber filter media is made from 100% microfine borosilicate glass fibers. Glass fiber filters are used where high flow rate and micron/sub-micron filtration is required. The filter media can be used for both liquid and air filtration. In the highest purity form, GENEQ offers a binderless “AE ” grade glass filter media. With its’ excellent purity,,using the FPAE series filter paper reduces the overall possibility of extractable organics commonly found in cellulose filter paper.Where greater structural strength filter papers are needed (high pressure drop, vacuum applications), either a spun polyester backing is used, Type FP5211, or a minimal amount of acrylic resin binder is used, Type FP2063 &FP2061, to keep up the integrity of the glass fibers during and after sampling/analysis.Some PM-10 sampling applications specifically call out for Whatman’s “EPM-2000 ”, the part number FP2000 .FP2000 was developed and produced especially for use in high volume PM-10 air sampling equipment that collects atmospheric particulates and aerosols.

PROPERTIES OF GLASS FIBER MEDIA

The borosilicate glass fibers are inert and resistant to all but strongly alkaline bases or acids such as hydrofluoric acid. The fibers are heat resistant and will only begin to soften at over 600 °C. The borosilicate glass has a refractive index of 1.51,and when immersed in a solvent of a similar refractive index like benzene,the fibers will be transparent. Particles collected on the media then become easier to visibly identify. NOTE: BENZENE HAS BEEN DETERMINED TO BE A TOXIC SUBSTANCE.

PARTICLE RETENTION

For air and gas filtration,collection of sub-micron (less than one micrometer in aerodynamic diameter)particles is sometimes required. In nuclear environmental air testing,the protocol is for sub-micron collection. Use of glass fiber media is therefore recommended. The test procedure for determining the effectiveness of particle retention is known as the DOP smoke test. In this test, DOP (di octyl phthalate)is heated,the vaporized compound is dispersed into theair where it is cools and condenses into mono-molecular particles of 0.3 micron size. By drawing these airborne particles through the filter media and measuring the amount of breakthrough particle,a retention efficiency is established. See tabular results in “General Performance Summary on Glass Fiber Paper ”. NOTE:DOP HAS BEEN DETERMINED TO BE A CARCINOGEN.

HYDROPHOBIC GLASS FIBER FILTER PAPER

Model FP2063-XX

This hydrophobic, high purity filter media is recommended for use in general purpose, high and low volume air sampling applications for particulate collection. It is composed of 100% high quality borosillicate glass microfibers. Both the FP2063 & FP2061 filter paper grades are excellent for the removal of micron and sub-micron size particulate from ambient air and stack gases. Because glass fibers are brittle and do not naturally bind together, a small amount of acrylic resin binder (composition of which is described in CFR title 21, Part,2260, filters, resin bonded, ASTM Spec.) is used to retain the filter paper integrity druring air sampling and routine handling. The total borosilicate glass microfiber composition found in the FP2063 & FP2061 filter media contains less than 5% acrylic resin binder.

Model FP2061-XX

This high purity filter paper has all the same properties of the type FP2063, except that it is hydrophilic. Choose the paper best suited for your sampling application and particule identifying method.

BINDERLESS, ULTRA-PURE, GLASS FIBER FILTER PAPER

Model FPAE-XX

This binderless, high efficiency, high purity, HEPA quality filter media is commonly used in the collection of alpha, beta, and gamma emitting particulate. It is an excellent all around analytical grade filtration media for use in the removal of micron and sub-micron size particulates from both liquids and gases.

Model FP2000-XX (Whatman EPM-2000)

The EPM-2000 grade paper was developed and produced especially for use in high volume PM-10 air sampling equipment that collects atmospheric particulates and aerosols. It is manufactured from 100% pure borosilicate glass of special purity enabling detailed chemical analysis of trace polluants to take place with the minimum of interference or backgroung. EPM-2000 was selected by the EPA to be the standard filter for use in the nationwide network of Hi-Vol air samplers. 8 x 10 inches sheets are individually numbered to facilitate identification.

ASHLESS CELLULOSE FILTER PAPER

Cellulose fiber filter paper such as the Whatman 41 ,is commonly used in quantitative analytical techniques such as gravimetric analysis.E.G.: To convert precipitate to a stable weighing form,a chemist may wish to ignite the filter paper containing collected precipitate in a pre-weighed crucible, thereby removing the filter paper with minimal and uniform residual “ash ”. Cellulose paper is also commonly used for smears or swipes .Cellulose paper is not recommended with pumps that can ’t overcome large pressure drops (e.g.battery operated centrifugal type)or,where required, to maintain a constant flow rate over the entire sampling period.

CARBON IMPREGRATED FILTER MEDIA

Carbon impregnated cotton fiber filter paper, type FPAIC, is found in applications where the determination of an airborne Iodine species are required.

Model FPACI-XX

Carbon impregnated cotton fiber filter media contains 50-55% Carbon by weight. The paper is available in all standard die sizes and is generally used to qualita- tively determine the presence of Iodine in a sampling environment. The paper resists most dilute acids (not suitable for warm alkaline solutions).

FP1441-XXX, Whatman, Grade 41: 20-25µm

The fastest ashless filter paper, recommended for analytical procedures involving coarse particles or gelatinous precipitates (i.e., iron or aluminum-hydroxides). Also used in quantitative air pollution analysis. Cellulose paper is also commonly used for smears or swipes.

TEFLON-GSKT-XX, Teflon Support Gaskets:

Teflon Support Gaskets may be placed above and below the filter paper disc creating a protective barrier between the occasional sharp edges of filter paper holder support screens and retaining rings.The inner &outer diameters of the Teflon rings are punched to a specifically tight tolerance to minimize any flow disturbance and to maximize filter collection media face exposure.Punched Teflon thickness is 0.020.

SPECIFICATIONS
	FP2063	FP2061	FP5211	FPAE	FP2000
Basic Weight	48lb/3000 sq.ft.	48lb/3000 sq.ft.	54lb/3000 sq.ft.	42lb/3000 sq.ft.	41lb/3000 sq.ft.
Caliper Thickness	0.016"@4psi	0.016"@4psi	0.015"@7.3psi	0.020"@0.5psi	0.017"
DOP Smoke Penetration @ 0.3um @32lpm	97%	97%	99.985%	99.99%	99.99%
Air Flow Resistance @32lpm	14.5 mm H₂O	14.5 mm H₂O	38 mm H₂O	48 mm H₂O	N/A
Binder	Acrylic	Acrylic	Acrylic	None	None
Backing	None	None	Spunbonded Polyester	None	None