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Martin Harper - One of the best experts on this subject based on the ideXlab platform.

  • Air Sampling filtration media collection efficiency for respirable size selective Sampling
    Aerosol Science and Technology, 2016
    Co-Authors: Keenan Monaghan, Mike Kashon, Martin Harper
    Abstract:

    ABSTRACTThe collection efficiencies of commonly used membrane Air Sampling filters in the ultrafine particle size range were investigated. Mixed cellulose ester (MCE; 0.45, 0.8, 1.2, and 5 μm pore sizes), polycarbonate (0.4, 0.8, 2, and 5 μm pore sizes), polytetrafluoroethylene (PTFE; 0.45, 1, 2, and 5 μm pore sizes), polyvinyl chloride (PVC; 0.8 and 5 μm pore sizes), and silver membrane (0.45, 0.8, 1.2, and 5 μm pore sizes) filters were exposed to polydisperse sodium chloride (NaCl) particles in the size range of 10–400 nm. Test aerosols were nebulized and introduced into a calm Air chamber through a diffusion dryer and aerosol neutralizer. The testing filters (37 mm diameter) were mounted in a conductive polypropylene filter-holder (cassette) within a metal testing tube. The experiments were conducted at flow rates between 1.7 and 11.2 l min−1. The particle size distributions of NaCl challenge aerosol were measured upstream and downstream of the test filters by a scanning mobility particle sizer (SMPS)....

  • Air Sampling filtration media collection efficiency for respirable size selective Sampling
    Aerosol Science and Technology, 2016
    Co-Authors: Jhycharm Soo, Keenan Monaghan, Mike Kashon, Taekhee Lee, Martin Harper
    Abstract:

    The collection efficiencies of commonly used membrane Air Sampling filters in the ultrafine particle size range were investigated. Mixed cellulose ester (MCE; 0.45, 0.8, 1.2, and 5 μm pore sizes), polycarbonate (0.4, 0.8, 2, and 5 μm pore sizes), polytetrafluoroethylene (PTFE; 0.45, 1, 2, and 5 μm pore sizes), polyvinyl chloride (PVC; 0.8 and 5 μm pore sizes), and silver membrane (0.45, 0.8, 1.2, and 5 μm pore sizes) filters were exposed to polydisperse sodium chloride (NaCl) particles in the size range of 10-400 nm. Test aerosols were nebulized and introduced into a calm Air chamber through a diffusion dryer and aerosol neutralizer. The testing filters (37 mm diameter) were mounted in a conductive polypropylene filter-holder (cassette) within a metal testing tube. The experiments were conducted at flow rates between 1.7 and 11.2 l min-1. The particle size distributions of NaCl challenge aerosol were measured upstream and downstream of the test filters by a scanning mobility particle sizer (SMPS). Three different filters of each type with at least three repetitions for each pore size were tested. In general, the collection efficiency varied with Airflow, pore size, and Sampling duration. In addition, both collection efficiency and pressure drop increased with decreased pore size and increased Sampling flow rate, but they differed among filter types and manufacturer. The present study confirmed that the MCE, PTFE, and PVC filters have a relatively high collection efficiency for challenge particles much smaller than their nominal pore size and are considerably more efficient than polycarbonate and silver membrane filters, especially at larger nominal pore sizes.

  • Performance evaluation of on-site colorimetric Air Sampling techniques.
    Applied occupational and environmental hygiene, 2001
    Co-Authors: Martin Harper
    Abstract:

    (2001). Performance Evaluation of On-Site Colorimetric Air Sampling Techniques. Applied Occupational and Environmental Hygiene: Vol. 16, No. 12, pp. 1092-1096.

Keenan Monaghan - One of the best experts on this subject based on the ideXlab platform.

  • Air Sampling filtration media collection efficiency for respirable size selective Sampling
    Aerosol Science and Technology, 2016
    Co-Authors: Keenan Monaghan, Mike Kashon, Martin Harper
    Abstract:

    ABSTRACTThe collection efficiencies of commonly used membrane Air Sampling filters in the ultrafine particle size range were investigated. Mixed cellulose ester (MCE; 0.45, 0.8, 1.2, and 5 μm pore sizes), polycarbonate (0.4, 0.8, 2, and 5 μm pore sizes), polytetrafluoroethylene (PTFE; 0.45, 1, 2, and 5 μm pore sizes), polyvinyl chloride (PVC; 0.8 and 5 μm pore sizes), and silver membrane (0.45, 0.8, 1.2, and 5 μm pore sizes) filters were exposed to polydisperse sodium chloride (NaCl) particles in the size range of 10–400 nm. Test aerosols were nebulized and introduced into a calm Air chamber through a diffusion dryer and aerosol neutralizer. The testing filters (37 mm diameter) were mounted in a conductive polypropylene filter-holder (cassette) within a metal testing tube. The experiments were conducted at flow rates between 1.7 and 11.2 l min−1. The particle size distributions of NaCl challenge aerosol were measured upstream and downstream of the test filters by a scanning mobility particle sizer (SMPS)....

  • Air Sampling filtration media collection efficiency for respirable size selective Sampling
    Aerosol Science and Technology, 2016
    Co-Authors: Jhycharm Soo, Keenan Monaghan, Mike Kashon, Taekhee Lee, Martin Harper
    Abstract:

    The collection efficiencies of commonly used membrane Air Sampling filters in the ultrafine particle size range were investigated. Mixed cellulose ester (MCE; 0.45, 0.8, 1.2, and 5 μm pore sizes), polycarbonate (0.4, 0.8, 2, and 5 μm pore sizes), polytetrafluoroethylene (PTFE; 0.45, 1, 2, and 5 μm pore sizes), polyvinyl chloride (PVC; 0.8 and 5 μm pore sizes), and silver membrane (0.45, 0.8, 1.2, and 5 μm pore sizes) filters were exposed to polydisperse sodium chloride (NaCl) particles in the size range of 10-400 nm. Test aerosols were nebulized and introduced into a calm Air chamber through a diffusion dryer and aerosol neutralizer. The testing filters (37 mm diameter) were mounted in a conductive polypropylene filter-holder (cassette) within a metal testing tube. The experiments were conducted at flow rates between 1.7 and 11.2 l min-1. The particle size distributions of NaCl challenge aerosol were measured upstream and downstream of the test filters by a scanning mobility particle sizer (SMPS). Three different filters of each type with at least three repetitions for each pore size were tested. In general, the collection efficiency varied with Airflow, pore size, and Sampling duration. In addition, both collection efficiency and pressure drop increased with decreased pore size and increased Sampling flow rate, but they differed among filter types and manufacturer. The present study confirmed that the MCE, PTFE, and PVC filters have a relatively high collection efficiency for challenge particles much smaller than their nominal pore size and are considerably more efficient than polycarbonate and silver membrane filters, especially at larger nominal pore sizes.

Mike Kashon - One of the best experts on this subject based on the ideXlab platform.

  • Air Sampling filtration media collection efficiency for respirable size selective Sampling
    Aerosol Science and Technology, 2016
    Co-Authors: Keenan Monaghan, Mike Kashon, Martin Harper
    Abstract:

    ABSTRACTThe collection efficiencies of commonly used membrane Air Sampling filters in the ultrafine particle size range were investigated. Mixed cellulose ester (MCE; 0.45, 0.8, 1.2, and 5 μm pore sizes), polycarbonate (0.4, 0.8, 2, and 5 μm pore sizes), polytetrafluoroethylene (PTFE; 0.45, 1, 2, and 5 μm pore sizes), polyvinyl chloride (PVC; 0.8 and 5 μm pore sizes), and silver membrane (0.45, 0.8, 1.2, and 5 μm pore sizes) filters were exposed to polydisperse sodium chloride (NaCl) particles in the size range of 10–400 nm. Test aerosols were nebulized and introduced into a calm Air chamber through a diffusion dryer and aerosol neutralizer. The testing filters (37 mm diameter) were mounted in a conductive polypropylene filter-holder (cassette) within a metal testing tube. The experiments were conducted at flow rates between 1.7 and 11.2 l min−1. The particle size distributions of NaCl challenge aerosol were measured upstream and downstream of the test filters by a scanning mobility particle sizer (SMPS)....

  • Air Sampling filtration media collection efficiency for respirable size selective Sampling
    Aerosol Science and Technology, 2016
    Co-Authors: Jhycharm Soo, Keenan Monaghan, Mike Kashon, Taekhee Lee, Martin Harper
    Abstract:

    The collection efficiencies of commonly used membrane Air Sampling filters in the ultrafine particle size range were investigated. Mixed cellulose ester (MCE; 0.45, 0.8, 1.2, and 5 μm pore sizes), polycarbonate (0.4, 0.8, 2, and 5 μm pore sizes), polytetrafluoroethylene (PTFE; 0.45, 1, 2, and 5 μm pore sizes), polyvinyl chloride (PVC; 0.8 and 5 μm pore sizes), and silver membrane (0.45, 0.8, 1.2, and 5 μm pore sizes) filters were exposed to polydisperse sodium chloride (NaCl) particles in the size range of 10-400 nm. Test aerosols were nebulized and introduced into a calm Air chamber through a diffusion dryer and aerosol neutralizer. The testing filters (37 mm diameter) were mounted in a conductive polypropylene filter-holder (cassette) within a metal testing tube. The experiments were conducted at flow rates between 1.7 and 11.2 l min-1. The particle size distributions of NaCl challenge aerosol were measured upstream and downstream of the test filters by a scanning mobility particle sizer (SMPS). Three different filters of each type with at least three repetitions for each pore size were tested. In general, the collection efficiency varied with Airflow, pore size, and Sampling duration. In addition, both collection efficiency and pressure drop increased with decreased pore size and increased Sampling flow rate, but they differed among filter types and manufacturer. The present study confirmed that the MCE, PTFE, and PVC filters have a relatively high collection efficiency for challenge particles much smaller than their nominal pore size and are considerably more efficient than polycarbonate and silver membrane filters, especially at larger nominal pore sizes.

Janusz Pawliszyn - One of the best experts on this subject based on the ideXlab platform.

  • Air Sampling with Solid Phase Microextraction
    2001 Sacramento CA July 29-August 1 2001, 2001
    Co-Authors: Jacek A. Koziel, Fabio Augusto, Janusz Pawliszyn
    Abstract:

    Solid phase microextraction (SPME) presents many advantages over conventional analytical methods by combining Sampling, pre-concentration and direct transfer of the VOCs into a standard gas chromatography (GC) system. Since its introduction SPME has been applied to the Sampling and analysis of environmental samples including Airborne VOCs and particulates. The first part of this paper presents theory of Air Sampling with SPME and an overview of the a few current methods for quantitative Air Sampling and VOC determination with SPME using grab (‘instantaneous”) and time-weighted average (TWA) modes. The second part of this paper is focused on the recent development of the theory and applications of rapid Air Sampling and quantification of VOCs in Air with adsorptive SPME fiber coating. This approach based on forced and controlled Air flow of sampled Air and diffusion-based calibration, reduces the effects of VOC competition and displacement. Experiments are currently conducted to apply the rapid SPME Sampling method to determination of chemical composition and concentrations of agricultural odors.

  • Air Sampling and analysis of volatile organic compounds with solid phase microextraction.
    Journal of the Air & Waste Management Association (1995), 2001
    Co-Authors: Jacek A. Koziel, Janusz Pawliszyn
    Abstract:

    ABSTRACT Solid phase microextraction (SPME) presents many advantages over conventional analytical methods by combining Sampling, preconcentration, and direct transfer of the analytes into a standard gas chromatograph (GC). Since its commercial introduction in the early 1990s, SPME has been successfully applied to the Sampling and analysis of environmental samples. This paper presents an overview of the current methods for Air Sampling and analysis with SPME using both grab and time-weighted average (TWA) modes. Methods include total volatile organic compounds (TVOCs), formaldehyde, and several target volatile organic compounds (VOCs). Field Sampling data obtained with these methods in indoor Air were validated with conventional methods based on sorbent tubes. The advantages and challenges associated with SPME for Air Sampling are also discussed. SPME is accurate, fast, sensitive, versatile, and cost-efficient, and could serve as a powerful alternative to conventional methods used by the research, industri...

  • Air Sampling with porous solid-phase microextraction fibers
    Analytical chemistry, 2000
    Co-Authors: Jacek A. Koziel, Mingyu Jia, Janusz Pawliszyn
    Abstract:

    A new, rapid Air Sampling/sample preparation methodology was investigated using adsorptive solid-phase microextraction (SPME) fiber coatings and nonequilibrium conditions for volatile organic compounds (VOCs). This method is the fastest extraction technique for Air Sampling at typical Airborne VOC concentrations. A theoretical model for the extraction was formulated based on the diffusion through the interface between the sampled (bulk) Air and the SPME coating. Parameters that affect the extraction process including Sampling time, Air velocity, Air temperature, and relative humidity were investigated with the porous (solid) PDMS/DVB and Carboxen/PDMS coatings. Very short Sampling times from 5 s to 1 min were used to minimize the effects of competitive adsorption and to calibrate the extraction process in the initial linear extraction region. The predicted amounts of extracted mass compared well with the measured amounts of target VOCs. Findings presented in this study extend the existing fundamental know...

Jhycharm Soo - One of the best experts on this subject based on the ideXlab platform.

  • Air Sampling filtration media collection efficiency for respirable size selective Sampling
    Aerosol Science and Technology, 2016
    Co-Authors: Jhycharm Soo, Keenan Monaghan, Mike Kashon, Taekhee Lee, Martin Harper
    Abstract:

    The collection efficiencies of commonly used membrane Air Sampling filters in the ultrafine particle size range were investigated. Mixed cellulose ester (MCE; 0.45, 0.8, 1.2, and 5 μm pore sizes), polycarbonate (0.4, 0.8, 2, and 5 μm pore sizes), polytetrafluoroethylene (PTFE; 0.45, 1, 2, and 5 μm pore sizes), polyvinyl chloride (PVC; 0.8 and 5 μm pore sizes), and silver membrane (0.45, 0.8, 1.2, and 5 μm pore sizes) filters were exposed to polydisperse sodium chloride (NaCl) particles in the size range of 10-400 nm. Test aerosols were nebulized and introduced into a calm Air chamber through a diffusion dryer and aerosol neutralizer. The testing filters (37 mm diameter) were mounted in a conductive polypropylene filter-holder (cassette) within a metal testing tube. The experiments were conducted at flow rates between 1.7 and 11.2 l min-1. The particle size distributions of NaCl challenge aerosol were measured upstream and downstream of the test filters by a scanning mobility particle sizer (SMPS). Three different filters of each type with at least three repetitions for each pore size were tested. In general, the collection efficiency varied with Airflow, pore size, and Sampling duration. In addition, both collection efficiency and pressure drop increased with decreased pore size and increased Sampling flow rate, but they differed among filter types and manufacturer. The present study confirmed that the MCE, PTFE, and PVC filters have a relatively high collection efficiency for challenge particles much smaller than their nominal pore size and are considerably more efficient than polycarbonate and silver membrane filters, especially at larger nominal pore sizes.