PTFE Membrane Filters Tech Tips
Particulate Sampling Filters
PTFE Membrane Filters Aerosol Sampling in Aggressive Chemical Environments
Tech Tips Back pressure on PTFE filters can vary within the same lot. It is not necessary to use a support pad when sampling with a laminated PTFE filter. Filter pore size ratings are based on liquid filtration ratings. Filters will retain much smaller particles from air (e.g., a 0.8-μm liquid rated filter will retain > 50% of particles as small as 0.08 μm). A typical laminated PTFE filter features two sides: the smooth membrane side and the rough laminate support side. The smooth side is easier to read under a microscope, therefore, expose the smooth membrane side to the air when collecting samples for microscopic analysis. The rough side holds dust more effectively; expose the rough laminate support side for gravimetric sampling.
Hydrophobic Low background for interference-free chemical determinations Strong and resistant to acids, bases, and solvents 13-mm filter meets NIOSH Method 5517 specifications Low tare mass for accurate gravimetric analysis Temperature resistant to 260 C (500 F) — autoclavable 60.0, 10.0, and 5.0-μm pore sizes
Ideal for aerosol sampling, especially in environments also containing water vapor SKC offers two types of polytetrafluoroethylene (PTFE) filters: 60.0, 10.0, and 5.0-μm pore size PTFE filters are pure PTFE microfibers fused together at intersection points. These hydrophobic membranes provide ultimate chemical resistance and are temperature stable to 260 C (500 F). 2.0, 1.0, and 0.5-μm pore size PTFE filters are comprised of a tighter PTFE membrane laminated onto a PTFE support. These filters have two distinct sides — the tight, smooth PTFE membrane and the rough PTFE support. The application determines the side exposed to air during sampling. See Tech Tip at left.
2.0, 1.0, and 0.5-μm pore sizes
PTFE Membrane Filters Diameter (mm) Pore Size (μm) 13 5.0 25 0.5 25 1.0 25 2.0 25 3.0 25 5.0 37 0.3
Support Pad‡ No No No No No No No
For coated filters see page 83
37 37 37 37 37 37 37 47 47 47 47 47 47
0.45 1.0 1.0 2.0 2.0 5.0 10.0 0.5 1.0 2.0 2.0 5.0 60.0
Yes Yes Yes Yes No Yes No No No No No No No
† Recommended for use with the Button Sampler, see page 93
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Notes unlaminated with laminated PTFE support with laminated PTFE support with laminated PTFE support with PMP support ring unlaminated for Anthrax/SARS, laminated spun-bound polyester; see preloaded on p. 75 on polypropylene support on polypropylene support with laminated PTFE support with laminated PTFE support with PMP support ring unlaminated unlaminated with laminated PTFE support with laminated PTFE support with PMP support ring with laminated PTFE support unlaminated unlaminated
Cat. No. 225-17-03 225-2708 225-2714 225-2726 225-1711† 225-1728 225-1722
Qty. 100 100 100 100 50 50 100
225-17-04 225-17-01 225-2705 225-27-07 225-1709 225-17A 225-1729 225-2753 225-2749 225-1747 225-2748 225-1724 225-1755
100 100 50 50 50 50 100 50 50 50 50 100 100
‡ Filter support pads available on page 87
SKC Ltd.
Phone: +44 (0)1258 480188
Particulate Sampling Filters
PTFE Membrane Filters Preloaded into Cassettes for User Convenience PTFE filters are the versatile choice for size-selective samplers (see samplers and filters listed below). The material’s unique properties make it ideal for gravimetric, chemical, and/or microscopic analysis of sample particulate. PTFE filters are used for aerosol sampling, air venting, and gas filtration. Specific applications include: Sampling for Lactic Acid: The pharmaceutical industry has designated lactic acid powder as the surrogate particulate to detect fugitive emissions from drug compounding and pill manufacturing. The SKC Filter Division developed a 25-mm conductive polypropylene cassette with 1.0-μm PTFE filter and polypropylene support pad to minimize wall losses and permit in situ extraction for enhanced recovery of lactic acid at nanogram levels. A proprietary analytical procedure is available from ALS Laboratory Group in Salt Lake City, Utah. See PTFE filter Cat. No. 225-1725 below. Sampling for Particulate Matter: PTFE filters with a PMP support ring are the recommended filters for particulate matter samplers such as the SKC Personal Modular Impactor (PMI, page 99), the Sioutas Impactor (page 100), the IMPACT Sampler (page 101), the Personal Environmental Monitor (PEM, page 98), and the Button Sampler (page 93). These filters feature low back pressure, which allows longer sampling periods at higher flow rates to enhance sensitivity of measurement. See PTFE filters Cat. Nos. 225-1709, 225-1747, and 225-1711 on page 74. Sampling for Metalworking Fluids (NIOSH Method 5524): PTFE filter Cat. No. 22527-07 (page 74) with a 2.0-μm pore size and laminated PTFE support may be used with the thoracic Parallel Particle Impactor (PPI, pages 96-97) to sample thoracic particulate according to NIOSH 5524 for metalworking fluids.
Preloaded PTFE Membrane Filters
All SKC preloaded filters include supports and are in SureSeal leak-free cassettes that require a SureSeal Cassette Opener (see p. 88).
Diameter (mm) 25 25 25 25 37 37 37
Filter Specifications PTFE, 1.0 μm, with polypropylene pad PTFE, 1.0 μm, with cellulose support PTFE, 1.0 μm, with polypropylene support pad PTFE, 2.0 μm, with 60-μm laminated support and polypropylene support pad PTFE, 0.3 μm, laminated with spunbound polyester with cellulose support; for Anthrax/SARS PTFE, 1.0 μm, with cellulose support PTFE, 2.0 μm, with cellulose ring
Cassette Description/Notes 2-piece conductive, goblet style 2-piece conductive, goblet style 2-piece black conductive, goblet style 2-piece black conductive, goblet style 3-piece clear styrene, banded
Cat. No. 225-1725 225-1716 225-1751
Qty. 50 50 50
225-1750
50
225-1723
50
For size-selective samplers see pages 90-101
3-piece clear styrene, banded 2-piece plastic, banded
225-1715 225-1713
50 50
For Sample Pumps, see pages 5-23 SKC Inc.
Phone: +1-724-941-9701
www.skcinc.com
75
PTFE Membrane Filters Aerosol Sampling in Aggressive Chemical Environments
Tech Tips Back pressure on PTFE filters can vary within the same lot. It is not necessary to use a support pad when sampling with a laminated PTFE filter. Filter pore size ratings are based on liquid filtration ratings. Filters will retain much smaller particles from air (e.g., a 0.8-μm liquid rated filter will retain > 50% of particles as small as 0.08 μm). A typical laminated PTFE filter features two sides: the smooth membrane side and the rough laminate support side. The smooth side is easier to read under a microscope, therefore, expose the smooth membrane side to the air when collecting samples for microscopic analysis. The rough side holds dust more effectively; expose the rough laminate support side for gravimetric sampling.
Hydrophobic Low background for interference-free chemical determinations Strong and resistant to acids, bases, and solvents 13-mm filter meets NIOSH Method 5517 specifications Low tare mass for accurate gravimetric analysis Temperature resistant to 260 C (500 F) — autoclavable 60.0, 10.0, and 5.0-μm pore sizes
Ideal for aerosol sampling, especially in environments also containing water vapor SKC offers two types of polytetrafluoroethylene (PTFE) filters: 60.0, 10.0, and 5.0-μm pore size PTFE filters are pure PTFE microfibers fused together at intersection points. These hydrophobic membranes provide ultimate chemical resistance and are temperature stable to 260 C (500 F). 2.0, 1.0, and 0.5-μm pore size PTFE filters are comprised of a tighter PTFE membrane laminated onto a PTFE support. These filters have two distinct sides — the tight, smooth PTFE membrane and the rough PTFE support. The application determines the side exposed to air during sampling. See Tech Tip at left.
2.0, 1.0, and 0.5-μm pore sizes
PTFE Membrane Filters Diameter (mm) Pore Size (μm) 13 5.0 25 0.5 25 1.0 25 2.0 25 3.0 25 5.0 37 0.3
Support Pad‡ No No No No No No No
For coated filters see page 83
37 37 37 37 37 37 37 47 47 47 47 47 47
0.45 1.0 1.0 2.0 2.0 5.0 10.0 0.5 1.0 2.0 2.0 5.0 60.0
Yes Yes Yes Yes No Yes No No No No No No No
† Recommended for use with the Button Sampler, see page 93
74
www.skcltd.com
Notes unlaminated with laminated PTFE support with laminated PTFE support with laminated PTFE support with PMP support ring unlaminated for Anthrax/SARS, laminated spun-bound polyester; see preloaded on p. 75 on polypropylene support on polypropylene support with laminated PTFE support with laminated PTFE support with PMP support ring unlaminated unlaminated with laminated PTFE support with laminated PTFE support with PMP support ring with laminated PTFE support unlaminated unlaminated
Cat. No. 225-17-03 225-2708 225-2714 225-2726 225-1711† 225-1728 225-1722
Qty. 100 100 100 100 50 50 100
225-17-04 225-17-01 225-2705 225-27-07 225-1709 225-17A 225-1729 225-2753 225-2749 225-1747 225-2748 225-1724 225-1755
100 100 50 50 50 50 100 50 50 50 50 100 100
‡ Filter support pads available on page 87
SKC Ltd.
Phone: +44 (0)1258 480188
Particulate Sampling Filters
PTFE Membrane Filters Preloaded into Cassettes for User Convenience PTFE filters are the versatile choice for size-selective samplers (see samplers and filters listed below). The material’s unique properties make it ideal for gravimetric, chemical, and/or microscopic analysis of sample particulate. PTFE filters are used for aerosol sampling, air venting, and gas filtration. Specific applications include: Sampling for Lactic Acid: The pharmaceutical industry has designated lactic acid powder as the surrogate particulate to detect fugitive emissions from drug compounding and pill manufacturing. The SKC Filter Division developed a 25-mm conductive polypropylene cassette with 1.0-μm PTFE filter and polypropylene support pad to minimize wall losses and permit in situ extraction for enhanced recovery of lactic acid at nanogram levels. A proprietary analytical procedure is available from ALS Laboratory Group in Salt Lake City, Utah. See PTFE filter Cat. No. 225-1725 below. Sampling for Particulate Matter: PTFE filters with a PMP support ring are the recommended filters for particulate matter samplers such as the SKC Personal Modular Impactor (PMI, page 99), the Sioutas Impactor (page 100), the IMPACT Sampler (page 101), the Personal Environmental Monitor (PEM, page 98), and the Button Sampler (page 93). These filters feature low back pressure, which allows longer sampling periods at higher flow rates to enhance sensitivity of measurement. See PTFE filters Cat. Nos. 225-1709, 225-1747, and 225-1711 on page 74. Sampling for Metalworking Fluids (NIOSH Method 5524): PTFE filter Cat. No. 22527-07 (page 74) with a 2.0-μm pore size and laminated PTFE support may be used with the thoracic Parallel Particle Impactor (PPI, pages 96-97) to sample thoracic particulate according to NIOSH 5524 for metalworking fluids.
Preloaded PTFE Membrane Filters
All SKC preloaded filters include supports and are in SureSeal leak-free cassettes that require a SureSeal Cassette Opener (see p. 88).
Diameter (mm) 25 25 25 25 37 37 37
Filter Specifications PTFE, 1.0 μm, with polypropylene pad PTFE, 1.0 μm, with cellulose support PTFE, 1.0 μm, with polypropylene support pad PTFE, 2.0 μm, with 60-μm laminated support and polypropylene support pad PTFE, 0.3 μm, laminated with spunbound polyester with cellulose support; for Anthrax/SARS PTFE, 1.0 μm, with cellulose support PTFE, 2.0 μm, with cellulose ring
Cassette Description/Notes 2-piece conductive, goblet style 2-piece conductive, goblet style 2-piece black conductive, goblet style 2-piece black conductive, goblet style 3-piece clear styrene, banded
Cat. No. 225-1725 225-1716 225-1751
Qty. 50 50 50
225-1750
50
225-1723
50
For size-selective samplers see pages 90-101
3-piece clear styrene, banded 2-piece plastic, banded
225-1715 225-1713
50 50
For Sample Pumps, see pages 5-23 SKC Inc.
Phone: +1-724-941-9701
www.skcinc.com
75
