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Sample records for air samples contained

  1. Sealed container sampling device

    NASA Technical Reports Server (NTRS)

    Hennigan, T. J.

    1969-01-01

    Sampling device, by means of a tapered needle, pierces a sealed container while maintaining the seal and either evacuates or pressurizes the container. This device has many applications in the chemical, preservative and battery-manufacturing industries.

  2. Remote possibly hazardous content container sampling device

    DOEpatents

    Volz, David L.

    1998-01-01

    The present invention relates to an apparatus capable of sampling enclosed containers, where the contents of the container is unknown. The invention includes a compressed air device capable of supplying air pressure, device for controlling the amount of air pressure applied, a pneumatic valve, a sampling device having a hollow, sampling insertion needle suspended therein and device to communicate fluid flow between the container and a containment vessel, pump or direct reading instrument.

  3. Inertial impaction air sampling device

    SciTech Connect

    Dewhurst, K.H.

    1987-12-10

    An inertial impactor to be used in an air sampling device for collection of respirable size particles in ambient air which may include a graphite furnace as the impaction substrate in a small-size, portable, direct analysis structure that gives immediate results and is totally self-contained allowing for remote and/or personal sampling. The graphite furnace collects suspended particles transported through the housing by means of the air flow system, and these particles may be analyzed for elements, quantitatively and qualitatively, by atomic absorption spectrophotometry. 3 figs.

  4. Inertial impaction air sampling device

    SciTech Connect

    Dewhurst, K.H.

    1990-05-22

    An inertial impactor is designed which is to be used in an air sampling device for collection of respirable size particles in ambient air. The device may include a graphite furnace as the impaction substrate in a small-size, portable, direct analysis structure that gives immediate results and is totally self-contained allowing for remote and/or personal sampling. The graphite furnace collects suspended particles transported through the housing by means of the air flow system, and these particles may be analyzed for elements, quantitatively and qualitatively, by atomic absorption spectrophotometry. 3 figs.

  5. Inertial impaction air sampling device

    DOEpatents

    Dewhurst, Katharine H.

    1990-01-01

    An inertial impactor to be used in an air sampling device for collection of respirable size particles in ambient air which may include a graphite furnace as the impaction substrate in a small-size, portable, direct analysis structure that gives immediate results and is totally self-contained allowing for remote and/or personal sampling. The graphite furnace collects suspended particles transported through the housing by means of the air flow system, and these particles may be analyzed for elements, quantitatively and qualitatively, by atomic absorption spectrophotometry.

  6. Dissolution actuated sample container

    SciTech Connect

    Nance, Thomas A.; McCoy, Frank T.

    2013-03-26

    A sample collection vial and process of using a vial is provided. The sample collection vial has an opening secured by a dissolvable plug. When dissolved, liquids may enter into the interior of the collection vial passing along one or more edges of a dissolvable blocking member. As the blocking member is dissolved, a spring actuated closure is directed towards the opening of the vial which, when engaged, secures the vial contents against loss or contamination.

  7. Air Sampling Filter

    NASA Technical Reports Server (NTRS)

    1980-01-01

    General Metal Works' Accu-Vol is a high-volume air sampling system used by many government agencies to monitor air quality for pollution control purposes. Procedure prevents possible test-invalidating contamination from materials other than particulate pollutants, caused by manual handling or penetration of windblown matter during transit, a cassette was developed in which the filter is sealed within a metal frame and protected in transit by a snap-on aluminum cover, thus handled only under clean conditions in the laboratory.

  8. Rapid Sampling from Sealed Containers

    SciTech Connect

    Johnston, R.G.; Garcia, A.R.E.; Martinez, R.K.; Baca, E.T.

    1999-02-28

    The authors have developed several different types of tools for sampling from sealed containers. These tools allow the user to rapidly drill into a closed container, extract a sample of its contents (gas, liquid, or free-flowing powder), and permanently reseal the point of entry. This is accomplished without exposing the user or the environment to the container contents, even while drilling. The entire process is completed in less than 15 seconds for a 55 gallon drum. Almost any kind of container can be sampled (regardless of the materials) with wall thicknesses up to 1.3 cm and internal pressures up to 8 atm. Samples can be taken from the top, sides, or bottom of a container. The sampling tools are inexpensive, small, and easy to use. They work with any battery-powered hand drill. This allows considerable safety, speed, flexibility, and maneuverability. The tools also permit the user to rapidly attach plumbing, a pressure relief valve, alarms, or other instrumentation to a container. Possible applications include drum venting, liquid transfer, container flushing, waste characterization, monitoring, sampling for archival or quality control purposes, emergency sampling by rapid response teams, counter-terrorism, non-proliferation and treaty verification, and use by law enforcement personnel during drug or environmental raids.

  9. A New Technique for Sampling Firn Air

    NASA Astrophysics Data System (ADS)

    Perron, F. E.; Dibb, J. E.; Albert, M. R.

    2004-12-01

    The discovery and subsequent interest in photochemical interactions between the polar snowpack and the atmosphere has spawned interest in reliable methods of measuring chemical concentrations in interstitial air. Consistent sampling of the interstitial air in the snowpack had been problematic due to great chemical differences possible from sampling different layers in the snow and the difficulties in acquiring a sample that could serve multiple investigators at the same time. This paper describes a new air sampling device that was developed to solve many of the sampling problems. This new system allows multiple simultaneous chemical analysis of air contained in the pore spaces of the arctic snowpack at unlimited increments from depths of 0 to 150 cm. The three major components are a 4 ft diameter highly UV transmittent acrylic "hood" with a 10 cm rim, a 10 cm diameter casing barrel, and an air probe head. These components operate along with a variety of sub-components that supplement the sampling process. The technique provides for a common sample collection, use for a variety of gases to be sampled, it eliminates short circuit air sampling, provides undisturbed snow for in-situ sampling at multiple sample depths in the same location. The design is discussed and possible extension as a platform for other sensors is described.

  10. Large panel design for containment air baffle

    DOEpatents

    Orr, Richard S.

    1992-01-01

    The movable air baffle shield means in accordance with the present invention provides an efficient method of cooling the space surrounding the containment vessel while also providing the capability of being moved away from the containment vessel during inspection. The containment apparatus comprises a generally cylindrical sealed containment vessel for containing at least a portion of a nuclear power generation plant, a disparate shield building surrounding and housing the containment vessel therein and spaced outwardly thereof so as to form an air annulus in the space between the shield building and the containment vessel, a shield baffle means positioned in the air annulus around at least a portion of the sides of the containment vessel providing a coolant path between the baffle means and the containment vessel to permit cooling of the containment vessel by air, the shield baffle means being movable to afford access to the containment vessel.

  11. Large panel design for containment air baffle

    DOEpatents

    Orr, R.S.

    1992-12-08

    The movable air baffle shield means in accordance with the present invention provides an efficient method of cooling the space surrounding the containment vessel while also providing the capability of being moved away from the containment vessel during inspection. The containment apparatus comprises a generally cylindrical sealed containment vessel for containing at least a portion of a nuclear power generation plant, a disparate shield building surrounding and housing the containment vessel therein and spaced outwardly thereof so as to form an air annulus in the space between the shield building and the containment vessel, a shield baffle means positioned in the air annulus around at least a portion of the sides of the containment vessel providing a coolant path between the baffle means and the containment vessel to permit cooling of the containment vessel by air, the shield baffle means being movable to afford access to the containment vessel. 9 figs.

  12. Air sampling of smallpox virus

    PubMed Central

    Thomas, G.

    1974-01-01

    Airborne smallpox virus has been recovered in an isolation hospital using an adhesive surface sampling technique in the presence of very low aerosol concentrations. Previous work in this field is reviewed. Successful recovery of airborne virus depends on sampling large volumes of air with a suitable sampler and thorough investigation of the whole sample taken for the presence of viable virus. More information on the characteristics and behaviour of airborne smallpox virus is needed in particular with regard to the future design and siting of smallpox isolation units. PMID:4371586

  13. Air Sampling System Evaluation Template

    SciTech Connect

    Blunt, Brent

    2000-05-09

    The ASSET1.0 software provides a template with which a user can evaluate an Air Sampling System against the latest version of ANSI N13.1 "Sampling and Monitoring Releases of Airborne Radioactive Substances from the Stacks and Ducts of Nuclear Facilities". The software uses the ANSI N13.1 PIC levels to establish basic design criteria for the existing or proposed sampling system. The software looks at such criteria as PIC level, type of radionuclide emissions, physical state of the radionuclide, nozzle entrance effects, particulate transmission effects, system and component accuracy and precision evaluations, and basic system operations to provide a detailed look at the subsystems of a monitoring and sampling system/program. A GAP evaluation can then be completed which leads to identification of design and operational flaws in the proposed systems. Corrective measures can then be limited to the GAPs.

  14. A Sample Return Container with Hermetic Seal

    NASA Technical Reports Server (NTRS)

    Kong, Kin Yuen; Rafeek, Shaheed; Sadick, Shazad; Porter, Christopher C.

    2000-01-01

    A sample return container is being developed by Honeybee Robotics to receive samples from a derivative of the Champollion/ST4 Sample Acquisition and Transfer Mechanism or other samplers and then hermetically seal samples for a sample return mission. The container is enclosed in a phase change material (PCM) chamber to prevent phase change during return and re-entry to earth. This container is designed to operate passively with no motors and actuators. Using the sampler's featured drill tip for interfacing, transfer-ring and sealing samples, the container consumes no electrical power and therefore minimizes sample temperature change. The circular container houses a few isolated canisters, which will be sealed individually for samples acquired from different sites or depths. The drill based sampler indexes each canister to the sample transfer position, below the index interface for sample transfer. After sample transfer is completed, the sampler indexes a seal carrier, which lines up seals with the openings of the canisters. The sampler moves to the sealing interface and seals the sample canisters one by one. The sealing interface can be designed to work with C-seals, knife edge seals and cup seals. Again, the sampler provides all sealing actuation. This sample return container and co-engineered sample acquisition system are being developed by Honeybee Robotics in collaboration with the JPL Exploration Technology program.

  15. First Apollo 11 sample return containers arrive at Ellington AFB

    NASA Technical Reports Server (NTRS)

    1969-01-01

    The first Apollo 11 sample return container, containing lunar surface material, arrives at Ellington Air Force Base by air from the Pacific recovery area. Happily posing for photographs with the rock box are (left to right) George M. Low, Manager, Apollo Spacecraft Program, Manned Spacecraft Center (MSC); U.S. Air Force Lt. Gen. Samuel C. Phillips, Apollo Program Director, Office of Manned Space Flight, NASA HQ.; George S. Trimble, MSC Deputy Director (almost obscured); Eugene G. Edmonds, MSC Photographic Technology Laboratory; RIchard S. Johnston (in back), Special Assistant to the MSC Director; Dr. Thomas O. Paine, NASA Administrator; and Dr. Robert R. Gilruth, MSC Director.

  16. Air sampling in the workplace. Final report

    SciTech Connect

    Hickey, E.E.; Stoetzel, G.A.; Strom, D.J.; Cicotte, G.R.; Wiblin, C.M.; McGuire, S.A.

    1993-09-01

    This report provides technical information on air sampling that will be useful for facilities following the recommendations in the NRC`s Regulatory Guide 8.25, Revision 1, ``Air sampling in the Workplace.`` That guide addresses air sampling to meet the requirements in NRC`s regulations on radiation protection, 10 CFR Part 20. This report describes how to determine the need for air sampling based on the amount of material in process modified by the type of material, release potential, and confinement of the material. The purposes of air sampling and how the purposes affect the types of air sampling provided are discussed. The report discusses how to locate air samplers to accurately determine the concentrations of airborne radioactive materials that workers will be exposed to. The need for and the methods of performing airflow pattern studies to improve the accuracy of air sampling results are included. The report presents and gives examples of several techniques that can be used to evaluate whether the airborne concentrations of material are representative of the air inhaled by workers. Methods to adjust derived air concentrations for particle size are described. Methods to calibrate for volume of air sampled and estimate the uncertainty in the volume of air sampled are described. Statistical tests for determining minimum detectable concentrations are presented. How to perform an annual evaluation of the adequacy of the air sampling is also discussed.

  17. Acetabular pneumatocyst containing air-fluid level.

    PubMed

    Narváez, J A; Narváez, J; Rodríguez-Mijarro, M; Quintero, J C

    1999-01-01

    The presence of intraosseous gas most commonly occurs in osteomyelitis, vacuum phenomenon, and postsurgery or posttraumatic states. Several cases of subchondral gas-filled lesions, called pneumatocysts, have also been described in the sacroiliac joint and clavicle, none of them with intralesional air-fluid level. These pneumatocysts are innocuous lesions of uncertain origin. We describe one case of acetabular pneumatocyst containing air-fluid level in a 62-year-old man with long-standing ankylosing spondylitis involving hip joint. To our knowledge, this is the first reported case of a pneumatocyst in an acetabular location containing air-fluid level.

  18. Air sampling with solid phase microextraction

    NASA Astrophysics Data System (ADS)

    Martos, Perry Anthony

    There is an increasing need for simple yet accurate air sampling methods. The acceptance of new air sampling methods requires compatibility with conventional chromatographic equipment, and the new methods have to be environmentally friendly, simple to use, yet with equal, or better, detection limits, accuracy and precision than standard methods. Solid phase microextraction (SPME) satisfies the conditions for new air sampling methods. Analyte detection limits, accuracy and precision of analysis with SPME are typically better than with any conventional air sampling methods. Yet, air sampling with SPME requires no pumps, solvents, is re-usable, extremely simple to use, is completely compatible with current chromatographic equipment, and requires a small capital investment. The first SPME fiber coating used in this study was poly(dimethylsiloxane) (PDMS), a hydrophobic liquid film, to sample a large range of airborne hydrocarbons such as benzene and octane. Quantification without an external calibration procedure is possible with this coating. Well understood are the physical and chemical properties of this coating, which are quite similar to those of the siloxane stationary phase used in capillary columns. The log of analyte distribution coefficients for PDMS are linearly related to chromatographic retention indices and to the inverse of temperature. Therefore, the actual chromatogram from the analysis of the PDMS air sampler will yield the calibration parameters which are used to quantify unknown airborne analyte concentrations (ppb v to ppm v range). The second fiber coating used in this study was PDMS/divinyl benzene (PDMS/DVB) onto which o-(2,3,4,5,6- pentafluorobenzyl) hydroxylamine (PFBHA) was adsorbed for the on-fiber derivatization of gaseous formaldehyde (ppb v range), with and without external calibration. The oxime formed from the reaction can be detected with conventional gas chromatographic detectors. Typical grab sampling times were as small as 5 seconds

  19. East Mountain Area 1995 air sampling results

    SciTech Connect

    Deola, R.A.

    1996-09-01

    Ambient air samples were taken at two locations in the East Mountain Area in conjunction with thermal testing at the Lurance Canyon Burn Site (LCBS). The samples were taken to provide measurements of particulate matter with a diameter less than or equal to 10 micrometers (PM{sub 10}) and volatile organic compounds (VOCs). This report summarizes the results of the sampling performed in 1995. The results from small-scale testing performed to determine the potentially produced air pollutants in the thermal tests are included in this report. Analytical results indicate few samples produced measurable concentrations of pollutants believed to be produced by thermal testing. Recommendations for future air sampling in the East Mountain Area are also noted.

  20. Radiological Air Sampling. Protocol Development for the Canadian Forces

    DTIC Science & Technology

    2003-03-01

    that filter must be removed from the sampler and counted by some method. If the efficiency of the radiation detector is D (in units of count rate per...unit activity), then the count rate R of the radiation detector will be R = CVFD. In practice, C is the unknown quantity. V is known from the sampling...Potential Solutions The problem, then, is that all air samples contain radon and thoron daughters that emit alpha, beta, and gamma radiation . Moreover

  1. Rapid cleanup of bacterial DNA from samples containing aerosol contaminants

    NASA Astrophysics Data System (ADS)

    Menking, Darrell E.; Kracke, Suzanne K.; Emanuel, Peter A.; Valdes, James J.

    1999-01-01

    Polymerase Chain Reaction (PCR) is an in vitro enzymatic, synthetic method used to amplify specific DNA sequences from organisms. Detection of DNA using gene probes allows for absolute identification not only of specific organisms, but also of genetic material in recombinant organisms. PCR is an exquisite biological method for detecting bacteria in aerosol samples. A major challenge facing detection of DNA from field samples is that they are almost sure to contain impurities, especially impurities that inhibit amplification through PCR. DNA is being extracted from air, sewage/stool samples, food, sputum, a water and sediment; however, multi- step, time consuming methods are required to isolate the DNA from the surrounding contamination. This research focuses on developing a method for rapid cleanup of DNA which combines extraction and purification of DNA while, at the same time, removing inhibitors from 'dirty samples' to produce purified, PCR-ready DNA. GeneReleaser produces PCR-ready DNA in a rapid five-minute protocol. GeneReleaser resin was able to clean up sample contain micrograms of typical aerosol and water contaminants. The advantages of using GR are that it is rapid, inexpensive, requires one-step, uses no hazardous material and produces PCR-ready DNA.

  2. Air samplings in a Campylobacter jejuni positive laying hen flock.

    PubMed

    Ahmed, Marwa Fawzy El Metwaly; Schulz, Jochen; Hartung, Joerg

    2013-01-01

    The air in laying hen houses contains high concentrations of airborne bacteria. The numbers of these bacteria can be influenced by the efficiency of the chosen sampling method. In the presented study, AGI-30 Impingers and the Coriolis(®)µ air Sampler were compared in terms of their efficiency in sampling aerobic mesophilic bacteria in a laying hen house. Measurements were conducted in a laying hen flock with high prevalences of C. jejuni in order to investigate if culturable cells of this organism can also be detected by the applied methods. Airborne dust was also analyzed for the presence of C. jejuni specific DNA to assess the possible occurrence of non-culturable C. jejuni in the hen house air. The numbers of mesophilic airborne bacteria ranged from 8 × 10(4) - 2 × 10(6) CFU/m(-3) when sampled using AGI-30 Impingers, and from 2 × 10(5) - 4 × 10(6) CFU/m -3 when sampled using a Coriolis(®)µ air Sampler. The concentrations detected simultaneously by both devices correlated well (rPearson = 0.755), but the Coriolis(®)µ air Sampler showed a significantly higher sampling efficiency (p<0.001). Although, the within flock prevalence of C. jejuni was high during the experiments (between 70-93%), neither of the air sampling methods could detect culturable C. jejuni from the air. However, C. jejuni specific DNA was detected in 15 out of 18 airborne dust samples by mapA PCR. Based on the results, it can be concluded that airborne culturable C. jejuni were not detectable, even with an efficient air sampler, because of their low concentration. Therefore, the risk of airborne infection to poultry workers on inhaling airborne C. jejuni seems negligible. Also, the transmission of culturable C. jejuni to neighboring farms by the airborne route is unlikely. Otherwise, the detection of airborne C. jejuni specific DNA suggests that non-culturable cells could appear in the hen house air, and in future it should be verified whether sampling stress of the air sampling methods

  3. Air Sampling Instruments for Evaluation of Atmospheric Contaminants. Fourth Edition.

    ERIC Educational Resources Information Center

    American Conference of Governmental Industrial Hygienists, Cincinnati, OH.

    This text, a revision and extension of the first three editions, consists of papers discussing the basic considerations in sampling air for specific purposes, sampler calibration, systems components, sample collectors, and descriptions of air-sampling instruments. (BT)

  4. More about sampling and estimation of mercaptans in air samples.

    PubMed

    Moliner-Martínez, Y; Herráez-Hernández, R; Molins-Legua, C; Verdú-Andrés, J; Avella-Oliver, M; Campíns-Falcó, P

    2013-03-15

    Several strategies have been developed for sampling and determination of volatile thiols. The selectivity and sensitivity of the proposed methodologies are achieved by using a specific derivatizing reagent. The different procedures assayed are based on air sampling followed by derivatization of the analytes with OPA and isoleucine in alkaline solution. The derivatization products are separated and determined by liquid chromatography and fluorescence detection. To start, the derivatization conditions and stability of the derivates have been studied in order to establish the storage conditions. In general, the strategies studied consisted on trapping and detivatization the thiol compound on different support; a solution (Impinger) or sorbent (C₁₈ cartridges or glass fiber filter). The analytical properties of the different strategies have been obtained and compared. Procedures are recommended upon specific situations.

  5. NEA Multi-Chamber Sample Return Container with Hermetic Sealing

    NASA Technical Reports Server (NTRS)

    Rafeek, Shaheed; Kong, Kin Yuen; Sadick, Shazad; Porter, Christopher C.

    2000-01-01

    A sample return container is being developed by Honeybee Robotics to receive samples from a derivative of the Champollion/ST4 Sample Acquisition and Transfer Mechanism or other samplers such as the 'Touch and Go' Surface Sampler (TGSS), and then hermetically seal the samples for a sample return mission. The container is enclosed in a phase change material (PCM) chamber to prevent phase change during return and re-entry to earth. This container is designed to operate passively with no motors and actuators. Using the rotation axis of the TGSS sampler for interfacing, transferring and sealing samples, the container consumes no electrical power and therefore minimizes sample temperature change. The circular container houses multiple isolated canisters, which will be sealed individually for samples acquired from different sites or depths. The TGSS based sampler indexes each canister to the sample transfer position, below the index interface for sample transfer. After sample transfer is completed, the sampler indexes a seal carrier, which lines up seals with the openings of the canisters. The sampler moves to the sealing interface and seals the sample canisters one by one. The sealing interface can be designed to work with C-seals, knife edge seals and cup seals. This sample return container is being developed by Honeybee Robotics in collaboration with the JPL Exploration Technology program. A breadboard system of the sample return container has been recently completed and tested. Additional information is contained in the original extended abstract.

  6. 40 CFR 61.34 - Air sampling.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS National Emission Standard for Beryllium § 61.34 Air... detect maximum concentrations of beryllium in the ambient air. (b) All monitoring sites shall be...

  7. 40 CFR 61.34 - Air sampling.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS National Emission Standard for Beryllium § 61.34 Air... detect maximum concentrations of beryllium in the ambient air. (b) All monitoring sites shall be...

  8. 40 CFR 61.34 - Air sampling.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS National Emission Standard for Beryllium § 61.34 Air... detect maximum concentrations of beryllium in the ambient air. (b) All monitoring sites shall be...

  9. 40 CFR 61.34 - Air sampling.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS National Emission Standard for Beryllium § 61.34 Air... detect maximum concentrations of beryllium in the ambient air. (b) All monitoring sites shall be...

  10. 40 CFR 61.34 - Air sampling.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS National Emission Standard for Beryllium § 61.34 Air... detect maximum concentrations of beryllium in the ambient air. (b) All monitoring sites shall be...

  11. Pressurized solid oxide fuel cell integral air accumular containment

    DOEpatents

    Gillett, James E.; Zafred, Paolo R.; Basel, Richard A.

    2004-02-10

    A fuel cell generator apparatus contains at least one fuel cell subassembly module in a module housing, where the housing is surrounded by a pressure vessel such that there is an air accumulator space, where the apparatus is associated with an air compressor of a turbine/generator/air compressor system, where pressurized air from the compressor passes into the space and occupies the space and then flows to the fuel cells in the subassembly module, where the air accumulation space provides an accumulator to control any unreacted fuel gas that might flow from the module.

  12. Minanre Gas Concentrators For Air Sampling

    SciTech Connect

    Dr. Seung Ho Hong

    2001-03-01

    The goal of this project was to demonstrate the feasibility of a compact, lightweight, gas-sampling device with rapid-cycle-time characteristics. The highlights of our Phase I work include: (1) Demonstration of a compact gas sampler with integrated heater. This device has an order of magnitude greater adsorption capacity and much faster heating/cooling times than commercial sorbent tubes. (2) Completion of computational fluid dynamics modeling of the gas sampler to determine airflow characteristics for various design options. These modeling efforts guided the development and testing of the Mesochannel Gas Sampler prototype. (3) Testing of the Mesochannel Gas Sampler in parallel with tests of two packed-bed samplers. These tests showed the Mesochannel Gas Sampler represents a substantial improvement compared with the packed-bed approach. Our mesochannel heat-exchanger/adsorber architecture allows very efficient use of adsorbent mass, high adsorbent loadings, and very low pressure drop, which makes possible very high air-sampling rates using a simple, low-power fan. This device is well-suited for collecting samples of trace-level contaminants. The integrated heater, which forms the adsorbent-coated mesochannel walls, allows direct heating of the adsorbent and results in very rapid desorption of the adsorbed species. We believe the Mesochannel Gas Sampler represents a promising technology for the improvement of trace-contaminant detection limits. In our Phase II proposal, we outline several improvements to the gas sampler that will further improve its performance.

  13. Evaluation of Sampling and Sample Preparation Modifications for Soil Containing Metallic Residues

    DTIC Science & Technology

    2012-01-01

    Depth Interval Number of Increments per Sample Field Implementation Sample Tool Selection Collection of Soil Sample Sample Processing Air Drying...86 159 29 Palms (CA)4 IA  Artillery/ Bombing 100 6 100 x 100 RDX 9.4 3.9 4.8 5.6 2.1 38 Hill AFB (UT)5 TTA  Thermal treatment 100 3 100 x 100...representation of the overall experimental design. Soil samples were transported to CRREL and air -dried on alumi- num trays. Once air -dried, each

  14. Separation and Sealing of a Sample Container Using Brazing

    NASA Technical Reports Server (NTRS)

    Bar-Cohen, Yoseph; Rivellini, Tommaso P.; Wincentsen, James E.; Gershman, Robert

    2007-01-01

    A special double-wall container and a process for utilizing the container are being developed to enable (1) acquisition of a sample of material in a dirty environment that may include a biological and/or chemical hazard; (2) sealing a lid onto the inner part of the container to hermetically enclose the sample; (3) separating the resulting hermetic container from the dirty environment; and (4) bringing that hermetic container, without any biological or chemical contamination of its outer surface, into a clean environment. The process is denoted S(exp 3)B (separation, seaming, and sealing using brazing) because sealing of the sample into the hermetic container, separating the container from the dirty environment, and bringing the container with a clean outer surface into the clean environment are all accomplished simultaneously with a brazing operation.

  15. Ambient Air Sampling During Quantum-dot Spray Deposition

    SciTech Connect

    Jankovic, John Timothy; Hollenbeck, Scott M

    2010-01-01

    Ambient air sampling for nano-size particle emissions was performed during spot spray coating operations with a Sono-Tek Exactacoat Benchtop system (ECB). The ECB consisted of the application equipment contained within an exhaust enclosure. The enclosure contained numerous small access openings, including an exhaust hook-up. Door access comprised most of the width and height of the front. The door itself was of the swing-out type. Two types of nanomaterials, Cadmium selenide (Cd-Se) quantum-dots (QDs) and Gold (Au) QDs, nominally 3.3 and 5 nm in diameter respectively, were applied during the evaluation. Median spray drop size was in the 20 to 60 micrometer size range.1 Surface coating tests were of short duration, on the order of one-half second per spray and ten spray applications between door openings. The enclosure was ventilated by connection to a high efficiency particulate aerosol (HEPA) filtered house exhaust system. The exhaust rate was nominally 80 ft3 per minute producing about 5 air changes per minute. Real time air monitoring with a scanning mobility particle size analyzer (SMPS ) with a size detection limit of 7 nm indicated a significant increase in the ambient air concentration upon early door opening. A handheld condensation particle counter (CPC) with a lower size limit of 10 nm did not record changes in the ambient background. This increase in the ambient was not observed when door opening was delayed for 2 minutes (~10 air changes). The ventilated enclosure controlled emissions except for cases of rapid door opening before the overspray could be removed by the exhaust. A time delay sufficient to provide 10 enclosure air changes (a concentration reduction of more than 99.99 %) before door opening prevented the release of aerosol particles in any size.2 Scanning-transmission electron microscopy (STEM) and atomic force microscopy (AFM) demonstrated the presence of agglomerates in the surfaces of the spray applied deposition. A filtered air sample of

  16. Systematic Evaluation of Aggressive Air Sampling for Bacillus ...

    EPA Pesticide Factsheets

    Report The primary objectives of this project were to evaluate the Aggressive Air Sampling (AAS) method compared to currently used surface sampling methods and to determine if AAS is a viable option for sampling Bacillus anthracis spores.

  17. Evaluation of an air drilling cuttings containment system

    SciTech Connect

    Westmoreland, J.

    1994-04-01

    Drilling at hazardous waste sites for environmental remediation or monitoring requires containment of all drilling fluids and cuttings to protect personnel and the environment. At many sites, air drilling techniques have advantages over other drilling methods, requiring effective filtering and containment of the return air/cuttings stream. A study of. current containment methods indicated improvements could be made in the filtering of radionuclides and volatile organic compounds, and in equipment like alarms, instrumentation or pressure safety features. Sandia National Laboratories, Dept. 61 11 Environmental Drilling Projects Group, initiated this work to address these concerns. A look at the industry showed that asbestos abatement equipment could be adapted for containment and filtration of air drilling returns. An industry manufacturer was selected to build a prototype machine. The machine was leased and put through a six-month testing and evaluation period at Sandia National Laboratories. Various materials were vacuumed and filtered with the machine during this time. In addition, it was used in an actual air drive drilling operation. Results of these tests indicate that the vacuum/filter unit will meet or exceed our drilling requirements. This vacuum/filter unit could be employed at a hazardous waste site or any site where drilling operations require cuttings and air containment.

  18. Sealing and External Sterilization of a Sample Container

    NASA Technical Reports Server (NTRS)

    Bar-Cohen, Yoseph; Badescu, Mircea; Bao, Xiaoqi; Sherrit, Stewart; Olorunsola, Ayoola

    2008-01-01

    A method of (1) sealing a sample of material acquired in a possibly b iologically contaminated ("dirty") environment into a hermetic conta iner, (2) sterilizing the outer surface of the container, then (3) d elivering the sealed container to a clean environment has been propos ed. The method now proposed was originally intended to be used to ret urn samples from Mars to Earth, but could also be used on Earth to t ransport material samples acquired in environments that contain biol ogical hazards and/or, in some cases, chemical hazards.

  19. Sampling Interplanetary Dust Particles from Antarctic Air

    NASA Astrophysics Data System (ADS)

    Taylor, S.; Lever, J. H.; Alexander, C. M. O'D.; Brownlee, D. E.; Messenger, S.; Littler, L. R.; Stroud, R. M.; Wozniakiewicz, P.; Clement, S.

    2016-08-01

    We are undertaking a NASA and NSF supported project to filter large volumes of clean Antarctic air to collect a broad range of cosmic dust, including CP-IDPs, rare ultra-carbonaceous particles and particles derived from specific meteor streams.

  20. Self-contained cryogenic gas sampling apparatus and method

    DOEpatents

    McManus, G.J.; Motes, B.G.; Bird, S.K.; Kotter, D.K.

    1996-03-26

    Apparatus for obtaining a whole gas sample, is composed of: a sample vessel having an inlet for receiving a gas sample; a controllable valve mounted for controllably opening and closing the inlet; a valve control coupled to the valve for opening and closing the valve at selected times; a portable power source connected for supplying operating power to the valve control; and a cryogenic coolant in thermal communication with the vessel for cooling the interior of the vessel to cryogenic temperatures. A method is described for obtaining an air sample using the apparatus described above, by: placing the apparatus at a location at which the sample is to be obtained; operating the valve control to open the valve at a selected time and close the valve at a selected subsequent time; and between the selected times maintaining the vessel at a cryogenic temperature by heat exchange with the coolant. 3 figs.

  1. Self-contained cryogenic gas sampling apparatus and method

    DOEpatents

    McManus, Gary J.; Motes, Billy G.; Bird, Susan K.; Kotter, Dale K.

    1996-01-01

    Apparatus for obtaining a whole gas sample, composed of: a sample vessel having an inlet for receiving a gas sample; a controllable valve mounted for controllably opening and closing the inlet; a valve control coupled to the valve for opening and closing the valve at selected times; a portable power source connected for supplying operating power to the valve control; and a cryogenic coolant in thermal communication with the vessel for cooling the interior of the vessel to cryogenic temperatures. A method of obtaining an air sample using the apparatus described above, by: placing the apparatus at a location at which the sample is to be obtained; operating the valve control to open the valve at a selected time and close the valve at a selected subsequent time; and between the selected times maintaining the vessel at a cryogenic temperature by heat exchange with the coolant.

  2. Electromembrane extraction from aqueous samples containing polar organic solvents.

    PubMed

    Seip, Knut Fredrik; Gjelstad, Astrid; Pedersen-Bjergaard, Stig

    2013-09-20

    Electromembrane extraction (EME) was performed from aqueous samples and from aqueous samples containing methanol, ethanol, dimethyl sulfoxide, and acetonitrile. The basic drugs pethidine, haloperidol, nortriptyline, methadone and loperamide were used as model analytes. Reversed phase (C18) HPLC with UV (235 nm) and MS detection was used for analysis of the samples. With no organic solvent in the sample, maximum recoveries were obtained after 5-10 min. The maximum recoveries ranged between 83 and 95%. With 50% (v/v) methanol, ethanol, or dimethyl sulfoxide in the sample, recoveries were comparable to those from an aqueous sample, but the time required reaching maximum recovery increased to 15-25 min. With 2-nitrophenyl octyl ether (NPOE) as the supported liquid membrane (SLM), a stable EME system was obtained for 50% (v/v) methanol, 50% (v/v) ethanol, or 75% (v/v) dimethyl sulfoxide in the sample solution. On the other hand, the EME system was unstable with acetonitrile in the sample, as this solvent partly dissolved the SLM. In addition, acetonitrile migrated through the SLM and caused a volume expansion of the acceptor solution. Other SLMs were also tested (ethyl nitrobenzene, isopropyl nitrobenzene, and dodecyl nitrobenzene), but were inferior to NPOE. As a practical example, EME on dried blood spot extracts (80% methanol) were tested, and proved highly successful. These observations showed that EME can be an effective way of preparing aqueous samples containing substantial amounts of an organic solvent.

  3. Venturi Air-Jet Vacuum Ejector For Sampling Air

    NASA Technical Reports Server (NTRS)

    Hill, Gerald F.; Sachse, Glen W.; Burney, L. Garland; Wade, Larry O.

    1990-01-01

    Venturi air-jet vacuum ejector pump light in weight, requires no electrical power, does not contribute heat to aircraft, and provides high pumping speeds at moderate suctions. High-pressure motive gas required for this type of pump bled from compressor of aircraft engine with negligible effect on performance of engine. Used as source of vacuum for differential-absorption CO-measurement (DACOM), modified to achieve in situ measurements of CO at frequency response of 10 Hz. Provides improvement in spatial resolution and potentially leads to capability to measure turbulent flux of CO by use of eddy-correlation technique.

  4. Detection of the Urban Release of a Bacillus anthracis Simulant by Air Sampling

    PubMed Central

    Garza, Alexander G.; Van Cuyk, Sheila M.; Brown, Michael J.

    2014-01-01

    In 2005 and 2009, the Pentagon Force Protection Agency (PFPA) staged deliberate releases of a commercially available organic pesticide containing Bacillus amyloliquefaciens to evaluate PFPA's biothreat response protocols. In concert with, but independent of, these releases, the Department of Homeland Security sponsored experiments to evaluate the efficacy of commonly employed air and surface sampling techniques for detection of an aerosolized biological agent. High-volume air samplers were placed in the expected downwind plume, and samples were collected before, during, and after the releases. Environmental surface and personal air samples were collected in the vicinity of the high-volume air samplers hours after the plume had dispersed. The results indicate it is feasible to detect the release of a biological agent in an urban area both during and after the release of a biological agent using high-volume air and environmental sampling techniques. PMID:24697146

  5. Detection of the urban release of a bacillus anthracis simulant by air sampling.

    PubMed

    Garza, Alexander G; Van Cuyk, Sheila M; Brown, Michael J; Omberg, Kristin M

    2014-01-01

    In 2005 and 2009, the Pentagon Force Protection Agency (PFPA) staged deliberate releases of a commercially available organic pesticide containing Bacillus amyloliquefaciens to evaluate PFPA's biothreat response protocols. In concert with, but independent of, these releases, the Department of Homeland Security sponsored experiments to evaluate the efficacy of commonly employed air and surface sampling techniques for detection of an aerosolized biological agent. High-volume air samplers were placed in the expected downwind plume, and samples were collected before, during, and after the releases. Environmental surface and personal air samples were collected in the vicinity of the high-volume air samplers hours after the plume had dispersed. The results indicate it is feasible to detect the release of a biological agent in an urban area both during and after the release of a biological agent using high-volume air and environmental sampling techniques.

  6. Sampling of air streams and incorporation of samples in the Microtox{trademark} toxicity testing system

    SciTech Connect

    Kleinheinz, G.T.; St. John, W.P.

    1997-10-01

    A study was conducted to develop a rapid and reliable method for the collection and incorporation of biofiltration air samples containing volatile organic compounds (VOCs) into the Microtox toxicity testing system. To date, no method exists for this type of assay. A constant stream of VOCs was generated by air stripping compounds from a complex mixture of petroleum hydrocarbons (PHCs). Samples were collected on coconut charcoal ORBO tubes and the VOCs extracted with methylene chloride. The compounds extracted were then solvent exchanged into dimethyl sulfoxide (DMSO) under gaseous nitrogen. The resulting DMSO extract was directly incorporated into the Microtox toxicity testing system. In order to determine the efficiency of the solvent exchange, the VOCs in the DMSO extract were then extracted into hexane and subsequently analyzed using gas chromatography (GC) with a flame ionization detector (FID). It was determined that all but the most volatile VOCs could be effectively transferred from the ORBO tubes to DMSO for Microtox testing. Potential trace amounts of residual methylene chloride in the DMSO extracts showed no adverse effects in the Microtox system when compared to control samples.

  7. Astronaut Alan Bean holds Special Environmental Sample Container

    NASA Technical Reports Server (NTRS)

    1969-01-01

    Astronaut Alan L. Bean, lunar module pilot for the Apollo 12 lunar landing mission, holds a Special Environmental Sample Container filled with lunar soil collected during the extravehicular activity (EVA) in which Astronauts Charles Conrad Jr., commander, and Bean participated. Connrad, who took this picture, is reflected in the helmet visor of the lunar module pilot.

  8. Workplace air monitoring and sampling practices at DOE facilities

    SciTech Connect

    Swinth, K.L.; Kenoyer, J.L.; Selby, J.M.; Vallario, E.J.; Burphy, B.L.

    1986-03-01

    Current air monitoring and sampling practices at DOE facilities were surveyed as a part of an air monitoring upgrade task. A comprehensive questionnaire was developed and distributed to DOE contractors through the DOE field offices. Twenty-six facilities returned a completed questionnaire. Questionnaire replies indicate diversity in air sampling and monitoring practices among DOE facilities. The difference among the facilities exist in monitoring and sampling instrumentation, procedures, calibration, analytical methods, detection levels, and action levels. Many of these differences could be attributed to different operational needs.

  9. Category V Compliant Container for Mars Sample Return Missions

    NASA Technical Reports Server (NTRS)

    Dolgin, Benjamin; Sanok, Joseph; Sevilla, Donald; Bement, Laurence J.

    2000-01-01

    A novel containerization technique that satisfies Planetary Protection (PP) Category V requirements has been developed and demonstrated on the mock-up of the Mars Sample Return Container. The proposed approach uses explosive welding with a sacrificial layer and cut-through-the-seam techniques. The technology produces a container that is free from Martian contaminants on an atomic level. The containerization technique can be used on any celestial body that may support life. A major advantage of the proposed technology is the possibility of very fast (less than an hour) verification of both containment and cleanliness with typical metallurgical laboratory equipment. No separate biological verification is required. In addition to Category V requirements, the proposed container presents a surface that is clean from any, even nonviable organisms, and any molecular fragments of biological origin that are unique to Mars or any other celestial body other than Earth.

  10. APPLICATION OF SEMIPERMEABLE MEMBRANE DEVICES TO INDOOR AIR SAMPLING

    EPA Science Inventory

    Semipermeable membrane devices (SPMDs) are a relatively new passive sampling technique for nonpolar organic compounds that have been extensively used for surface water sampling. A small body of literature indicates that SPMDs are also useful for air sampling. Because SPMDs ha...

  11. EML Surface Air Sampling Program, 1990--1993 data

    SciTech Connect

    Larsen, R.J.; Sanderson, C.G.; Kada, J.

    1995-11-01

    Measurements of the concentrations of specific atmospheric radionuclides in air filter samples collected for the Environmental Measurements Laboratory`s Surface Air Sampling Program (SASP) during 1990--1993, with the exception of April 1993, indicate that anthropogenic radionuclides, in both hemispheres, were at or below the lower limits of detection for the sampling and analytical techniques that were used to collect and measure them. The occasional detection of {sup 137}Cs in some air filter samples may have resulted from resuspension of previously deposited debris. Following the April 6, 1993 accident and release of radionuclides into the atmosphere at a reprocessing plant in the Tomsk-7 military nuclear complex located 16 km north of the Siberian city of Tomsk, Russia, weekly air filter samples from Barrow, Alaska; Thule, Greenland and Moosonee, Canada were selected for special analyses. The naturally occurring radioisotopes that the authors measure, {sup 7}Be and {sup 210}Pb, continue to be detected in most air filter samples. Variations in the annual mean concentrations of {sup 7}Be at many of the sites appear to result primarily from changes in the atmospheric production rate of this cosmogenic radionuclide. Short-term variations in the concentrations of {sup 7}Be and {sup 210}Pb continued to be observed at many sites at which weekly air filter samples were analyzed. The monthly gross gamma-ray activity and the monthly mean surface air concentrations of {sup 7}Be, {sup 95}Zr, {sup 137}Cs, {sup 144}Ce, and {sup 210}Pb measured at sampling sites in SASP during 1990--1993 are presented. The weekly mean surface air concentrations of {sup 7}Be, {sup 95}Zr, {sup 137}Cs, {sup 144}Ce, and {sup 210}Pb for samples collected during 1990--1993 are given for 17 sites.

  12. [Ambient and enclosed space air sampling for determination of contaminants].

    PubMed

    Dorogova, V B

    2010-01-01

    The paper touches upon the issues how to correctly and maximally take single and average daily samples of ambient, residential and public building, and enclosed space air for further tests for the content of hazardous substances. The paper is debated.

  13. Solid waste transuranic storage and assay facility indoor air sampling

    SciTech Connect

    Pingel, L.A., Westinghouse Hanford

    1996-08-20

    The purpose of the study is to collect and analyze samples of the indoor air at the Transuranic Storage and Assay Facility (TRUSAF), Westinghouse Hanford. A modified US EPA TO-14 methodology, using gas chromatography/mass spectrography, may be used for the collection and analysis of the samples. The information obtained will be used to estimate the total release of volatile organic compounds from TRUSAF to determine the need for air emmission permits.

  14. Concepts for Environmental Radioactive Air Sampling and Monitoring

    SciTech Connect

    Barnett, J. Matthew

    2011-11-04

    Environmental radioactive air sampling and monitoring is becoming increasingly important as regulatory agencies promulgate requirements for the measurement and quantification of radioactive contaminants. While researchers add to the growing body of knowledge in this area, events such as earthquakes and tsunamis demonstrate how nuclear systems can be compromised. The result is the need for adequate environmental monitoring to assure the public of their safety and to assist emergency workers in their response. Two forms of radioactive air monitoring include direct effluent measurements and environmental surveillance. This chapter presents basic concepts for direct effluent sampling and environmental surveillance of radioactive air emissions, including information on establishing the basis for sampling and/or monitoring, criteria for sampling media and sample analysis, reporting and compliance, and continual improvement.

  15. Development of sealed sample containers and high resolution micro-tomography

    SciTech Connect

    Uesugi, Kentaro Takeuchi, Akihisa; Suzuki, Yoshio; Hamada, Hiroshi

    2016-01-28

    A sample container and a high resolution micro-tomography system have been developed at BL47XU at SPring-8. The container is made of a SiN membrane in a shape of truncated pyramid, which makes it possible to exclude oxygen and moisture in the air. The sample rotation stage for tomography is set downward to keep the sample in the container without any glue. The spatial resolution and field of view are 300 nm and 110 μm using a Fresnel zone plate objective with an outermost zone width of 100 nm at 8 keV, respectively. The scan time is about 20 minutes for 1800 projections. A 3-D image of an asteroid particle was successfully obtained without adhesive and contamination.

  16. EVALUATION OF AIR CLEANING SYSTEMS FOR FFTF CONTAINMENT MARGINS

    SciTech Connect

    POSTMA, A K.; HILLIARD, R K.

    1980-08-01

    Alternative air cleaning concepts were evaluated for possible application to FFTF containment margins. For evaluation purposes, it was assumed that the air cleaning system must process 3.07 m{sup 3}/s (6500 ACFM) of gas containing sodium compound aerosols (mainly NaOH) at temperatures up to 4070C (7000 F) and pressures up to 0.184 MPa (26.4 psia) and accommodate 5450 kg (12,000 lb) of aerosol material. Three systems designed for 90% efficient removal (a venturi scrubber, a submerged gravel scrubber and a spray scrubber) were compared. The submerged gravel scrubber and the venturi scrubber were rated as prime candidates. Four systems designed for 99% removal efficiency (the two optimum scrubbers chosen for 90% removal efficiency fitted with fibrous elements, a sand and gravel filter and a HEPA filter bank) were compared. The tI~ scrubbers were again rated as prime candidates. Both the sand and gravel filter and the HEPA filter bank were found to be excessively large and costly. Considerable experience supports the use of the optimum scrubber systems and it is concluded that their use is technically feasible for the FFTF containment margins application.

  17. Presence of organophosphorus pesticide oxygen analogs in air samples

    NASA Astrophysics Data System (ADS)

    Armstrong, Jenna L.; Fenske, Richard A.; Yost, Michael G.; Galvin, Kit; Tchong-French, Maria; Yu, Jianbo

    2013-02-01

    A number of recent toxicity studies have highlighted the increased potency of oxygen analogs (oxons) of several organophosphorus (OP) pesticides. These findings were a major concern after environmental oxons were identified in environmental samples from air and surfaces following agricultural spray applications in California and Washington State. This paper reports on the validity of oxygen analog measurements in air samples for the OP pesticide, chlorpyrifos. Controlled environmental and laboratory experiments were used to examine artificial formation of chlorpyrifos-oxon using OSHA Versatile Sampling (OVS) tubes as recommended by NIOSH method 5600. Additionally, we compared expected chlorpyrifos-oxon attributable to artificial transformation to observed chlorpyrifos-oxon in field samples from a 2008 Washington State Department of Health air monitoring study using non-parametric statistical methods. The amount of artificially transformed oxon was then modeled to determine the amount of oxon present in the environment. Toxicity equivalency factors (TEFs) for chlorpyrifos-oxon were used to calculate chlorpyrifos-equivalent air concentrations. The results demonstrate that the NIOSH-recommended sampling matrix (OVS tubes with XAD-2 resin) was found to artificially transform up to 30% of chlorpyrifos to chlorpyrifos-oxon, with higher percentages at lower concentrations (<30 ng m-3) typical of ambient or residential levels. Overall, the 2008 study data had significantly greater oxon than expected by artificial transformation, but the exact amount of environmental oxon in air remains difficult to quantify with the current sampling method. Failure to conduct laboratory analysis for chlorpyrifos-oxon may result in underestimation of total pesticide concentration when using XAD-2 resin matrices for occupational or residential sampling. Alternative methods that can accurately measure both OP pesticides and their oxygen analogs should be used for air sampling, and a toxicity

  18. A simple novel device for air sampling by electrokinetic capture

    DOE PAGES

    Gordon, Julian; Gandhi, Prasanthi; Shekhawat, Gajendra; ...

    2015-12-27

    A variety of different sampling devices are currently available to acquire air samples for the study of the microbiome of the air. All have a degree of technical complexity that limits deployment. Here, we evaluate the use of a novel device, which has no technical complexity and is easily deployable. An air-cleaning device powered by electrokinetic propulsion has been adapted to provide a universal method for collecting samples of the aerobiome. Plasma-induced charge in aerosol particles causes propulsion to and capture on a counter-electrode. The flow of ions creates net bulk airflow, with no moving parts. A device and electrodemore » assembly have been re-designed from air-cleaning technology to provide an average air flow of 120 lpm. This compares favorably with current air sampling devices based on physical air pumping. Capture efficiency was determined by comparison with a 0.4 μm polycarbonate reference filter, using fluorescent latex particles in a controlled environment chamber. Performance was compared with the same reference filter method in field studies in three different environments. For 23 common fungal species by quantitative polymerase chain reaction (qPCR), there was 100 % sensitivity and apparent specificity of 87%, with the reference filter taken as “gold standard.” Further, bacterial analysis of 16S RNA by amplicon sequencing showed equivalent community structure captured by the electrokinetic device and the reference filter. Unlike other current air sampling methods, capture of particles is determined by charge and so is not controlled by particle mass. We analyzed particle sizes captured from air, without regard to specific analyte by atomic force microscopy: particles at least as low as 100 nM could be captured from ambient air. This work introduces a very simple plug-and-play device that can sample air at a high-volume flow rate with no moving parts and collect particles down to the sub-micron range. In conclusion, the performance of

  19. A simple novel device for air sampling by electrokinetic capture

    SciTech Connect

    Gordon, Julian; Gandhi, Prasanthi; Shekhawat, Gajendra; Frazier, Angel; Hampton-Marcell, Jarrad; Gilbert, Jack A.

    2015-12-27

    A variety of different sampling devices are currently available to acquire air samples for the study of the microbiome of the air. All have a degree of technical complexity that limits deployment. Here, we evaluate the use of a novel device, which has no technical complexity and is easily deployable. An air-cleaning device powered by electrokinetic propulsion has been adapted to provide a universal method for collecting samples of the aerobiome. Plasma-induced charge in aerosol particles causes propulsion to and capture on a counter-electrode. The flow of ions creates net bulk airflow, with no moving parts. A device and electrode assembly have been re-designed from air-cleaning technology to provide an average air flow of 120 lpm. This compares favorably with current air sampling devices based on physical air pumping. Capture efficiency was determined by comparison with a 0.4 μm polycarbonate reference filter, using fluorescent latex particles in a controlled environment chamber. Performance was compared with the same reference filter method in field studies in three different environments. For 23 common fungal species by quantitative polymerase chain reaction (qPCR), there was 100 % sensitivity and apparent specificity of 87%, with the reference filter taken as “gold standard.” Further, bacterial analysis of 16S RNA by amplicon sequencing showed equivalent community structure captured by the electrokinetic device and the reference filter. Unlike other current air sampling methods, capture of particles is determined by charge and so is not controlled by particle mass. We analyzed particle sizes captured from air, without regard to specific analyte by atomic force microscopy: particles at least as low as 100 nM could be captured from ambient air. This work introduces a very simple plug-and-play device that can sample air at a high-volume flow rate with no moving parts and collect particles down to the sub-micron range. In conclusion, the performance of the

  20. Surface charge accumulation of particles containing radionuclides in open air.

    PubMed

    Kim, Yong-ha; Yiacoumi, Sotira; Tsouris, Costas

    2015-05-01

    Radioactivity can induce charge accumulation on radioactive particles. However, electrostatic interactions caused by radioactivity are typically neglected in transport modeling of radioactive plumes because it is assumed that ionizing radiation leads to charge neutralization. The assumption that electrostatic interactions caused by radioactivity are negligible is evaluated here by examining charge accumulation and neutralization on particles containing radionuclides in open air. A charge-balance model is employed to predict charge accumulation on radioactive particles. It is shown that particles containing short-lived radionuclides can be charged with multiple elementary charges through radioactive decay. The presence of radioactive particles can significantly modify the particle charge distribution in open air and yield an asymmetric bimodal charge distribution, suggesting that strong electrostatic particle interactions may occur during short- and long-range transport of radioactive particles. Possible effects of transported radioactive particles on electrical properties of the local atmosphere are reported. The study offers insight into transport characteristics of airborne radionuclides. Results are useful in atmospheric transport modeling of radioactive plumes.

  1. Surface charge accumulation of particles containing radionuclides in open air

    SciTech Connect

    Kim, Yong-ha; Yiacoumi, Sotira; Tsouris, Costas

    2015-05-01

    Radioactivity can induce charge accumulation on radioactive particles. But, electrostatic interactions caused by radioactivity are typically neglected in transport modeling of radioactive plumes because it is assumed that ionizing radiation leads to charge neutralization. The assumption that electrostatic interactions caused by radioactivity are negligible is evaluated here by examining charge accumulation and neutralization on particles containing radionuclides in open air. Moreover, a charge-balance model is employed to predict charge accumulation on radioactive particles. It is shown that particles containing short-lived radionuclides can be charged with multiple elementary charges through radioactive decay. The presence of radioactive particles can significantly modify the particle charge distribution in open air and yield an asymmetric bimodal charge distribution, suggesting that strong electrostatic particle interactions may occur during short- and long-range transport of radioactive particles. Possible effects of transported radioactive particles on electrical properties of the local atmosphere are reported. Our study offers insight into transport characteristics of airborne radionuclides. Results are useful in atmospheric transport modeling of radioactive plumes.

  2. Surface charge accumulation of particles containing radionuclides in open air

    DOE PAGES

    Kim, Yong-ha; Yiacoumi, Sotira; Tsouris, Costas

    2015-05-01

    Radioactivity can induce charge accumulation on radioactive particles. But, electrostatic interactions caused by radioactivity are typically neglected in transport modeling of radioactive plumes because it is assumed that ionizing radiation leads to charge neutralization. The assumption that electrostatic interactions caused by radioactivity are negligible is evaluated here by examining charge accumulation and neutralization on particles containing radionuclides in open air. Moreover, a charge-balance model is employed to predict charge accumulation on radioactive particles. It is shown that particles containing short-lived radionuclides can be charged with multiple elementary charges through radioactive decay. The presence of radioactive particles can significantly modify themore » particle charge distribution in open air and yield an asymmetric bimodal charge distribution, suggesting that strong electrostatic particle interactions may occur during short- and long-range transport of radioactive particles. Possible effects of transported radioactive particles on electrical properties of the local atmosphere are reported. Our study offers insight into transport characteristics of airborne radionuclides. Results are useful in atmospheric transport modeling of radioactive plumes.« less

  3. Innovations in air sampling to detect plant pathogens.

    PubMed

    West, Js; Kimber, Rbe

    2015-01-01

    Many innovations in the development and use of air sampling devices have occurred in plant pathology since the first description of the Hirst spore trap. These include improvements in capture efficiency at relatively high air-volume collection rates, methods to enhance the ease of sample processing with downstream diagnostic methods and even full automation of sampling, diagnosis and wireless reporting of results. Other innovations have been to mount air samplers on mobile platforms such as UAVs and ground vehicles to allow sampling at different altitudes and locations in a short space of time to identify potential sources and population structure. Geographical Information Systems and the application to a network of samplers can allow a greater prediction of airborne inoculum and dispersal dynamics. This field of technology is now developing quickly as novel diagnostic methods allow increasingly rapid and accurate quantifications of airborne species and genetic traits. Sampling and interpretation of results, particularly action-thresholds, is improved by understanding components of air dispersal and dilution processes and can add greater precision in the application of crop protection products as part of integrated pest and disease management decisions. The applications of air samplers are likely to increase, with much greater adoption by growers or industry support workers to aid in crop protection decisions. The same devices are likely to improve information available for detection of allergens causing hay fever and asthma or provide valuable metadata for regional plant disease dynamics.

  4. Innovations in air sampling to detect plant pathogens

    PubMed Central

    West, JS; Kimber, RBE

    2015-01-01

    Many innovations in the development and use of air sampling devices have occurred in plant pathology since the first description of the Hirst spore trap. These include improvements in capture efficiency at relatively high air-volume collection rates, methods to enhance the ease of sample processing with downstream diagnostic methods and even full automation of sampling, diagnosis and wireless reporting of results. Other innovations have been to mount air samplers on mobile platforms such as UAVs and ground vehicles to allow sampling at different altitudes and locations in a short space of time to identify potential sources and population structure. Geographical Information Systems and the application to a network of samplers can allow a greater prediction of airborne inoculum and dispersal dynamics. This field of technology is now developing quickly as novel diagnostic methods allow increasingly rapid and accurate quantifications of airborne species and genetic traits. Sampling and interpretation of results, particularly action-thresholds, is improved by understanding components of air dispersal and dilution processes and can add greater precision in the application of crop protection products as part of integrated pest and disease management decisions. The applications of air samplers are likely to increase, with much greater adoption by growers or industry support workers to aid in crop protection decisions. The same devices are likely to improve information available for detection of allergens causing hay fever and asthma or provide valuable metadata for regional plant disease dynamics. PMID:25745191

  5. [A membrane filter sampling method for determining microbial air pollution].

    PubMed

    Cherneva, P; Kiranova, A

    1996-01-01

    The method is a contribution in the evaluation of the exposition and the control of the standards for organic powders. The method concerns the sample-taking procedure and the analysis-making technique for determining of the concentration of the microbial pollution of the air. It is based on filtering of some amount of air through a membrane filter which is then processed for cultivating of microbial colonies on its surface. The results are obtained in number of microbial colonies per unit of air. The method presents opportunity to select and vary the filtered volume of air, to determine the respirable fraction, to determine the personal exposition, as well as for the simultaneous determining of the microbial pollution together with other important parameters of the particle pollutants of the air (metal, fibre and others).

  6. Formaldehyde quantitation in air samples by thiazolidine derivatization: Factors affecting analysis

    SciTech Connect

    Yasuhara, A.; Shibamoto, T. )

    1989-11-01

    A new method for the determination of trace levels of formaldehyde in air was developed and validated. The method is based on the reaction of formaldehyde with cysteamine to form thiazolidine. Air samples containing trace levels of formaldehyde were prepared from paraformaldehyde. The percent yield of formaldehyde from paraformaldehyde was 85.1 +/- 1.14%. Air samples were bubbled into an aqueous cysteamine trap. Thiazolidine formed from formaldehyde and cysteamine in the trap was determined by gas chromatography with a fused silica capillary column and a nitrogen-phosphorus detector (NPD). The lowest detection level for thiazolidine was 17.2 pg, equivalent to 5.80 pg formaldehyde. The recovery efficiency of trace gas phase formaldehyde in air was greater than 90%. Formaldehyde levels in ambient laboratory air were 48.9-56.2 ppb (v/v).

  7. Microanalysis study of archaeological mural samples containing Maya blue pigment

    NASA Astrophysics Data System (ADS)

    Sánchez del Río, M.; Martinetto, P.; Somogyi, A.; Reyes-Valerio, C.; Dooryhée, E.; Peltier, N.; Alianelli, L.; Moignard, B.; Pichon, L.; Calligaro, T.; Dran, J.-C.

    2004-10-01

    Elemental analysis by X-ray fluorescence and particle induced X-ray emission is applied to the study of several Mesoamerican mural samples containing blue pigments. The most characteristic blue pigment is Maya blue, a very stable organo-clay complex original from Maya culture and widely used in murals, pottery and sculptures in a vast region of Mesoamerica during the pre-hispanic time (from VIII century) and during the colonization until 1580. The mural samples come from six different archaeological sites (four pre-hispanic and two from XVI century colonial convents). The correlation between the presence of some elements and the pigment colour is discussed. From the comparative study of the elemental concentration, some conclusions are drawn on the nature of the pigments and the technology used.

  8. Adventitious Carbon on Primary Sample Containment Metal Surfaces

    NASA Technical Reports Server (NTRS)

    Calaway, M. J.; Fries, M. D.

    2015-01-01

    Future missions that return astromaterials with trace carbonaceous signatures will require strict protocols for reducing and controlling terrestrial carbon contamination. Adventitious carbon (AC) on primary sample containers and related hardware is an important source of that contamination. AC is a thin film layer or heterogeneously dispersed carbonaceous material that naturally accrues from the environment on the surface of atmospheric exposed metal parts. To test basic cleaning techniques for AC control, metal surfaces commonly used for flight hardware and curating astromaterials at JSC were cleaned using a basic cleaning protocol and characterized for AC residue. Two electropolished stainless steel 316L (SS- 316L) and two Al 6061 (Al-6061) test coupons (2.5 cm diameter by 0.3 cm thick) were subjected to precision cleaning in the JSC Genesis ISO class 4 cleanroom Precision Cleaning Laboratory. Afterwards, the samples were analyzed by X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy.

  9. DUS II SOIL GAS SAMPLING AND AIR INJECTION TEST RESULTS

    SciTech Connect

    Noonkester, J.; Jackson, D.; Jones, W.; Hyde, W.; Kohn, J.; Walker, R.

    2012-09-20

    Soil vapor extraction (SVE) and air injection well testing was performed at the Dynamic Underground Stripping (DUS) site located near the M-Area Settling Basin (referred to as DUS II in this report). The objective of this testing was to determine the effectiveness of continued operation of these systems. Steam injection ended on September 19, 2009 and since this time the extraction operations have utilized residual heat that is present in the subsurface. The well testing campaign began on June 5, 2012 and was completed on June 25, 2012. Thirty-two (32) SVE wells were purged for 24 hours or longer using the active soil vapor extraction (ASVE) system at the DUS II site. During each test five or more soil gas samples were collected from each well and analyzed for target volatile organic compounds (VOCs). The DUS II site is divided into four parcels (see Figure 1) and soil gas sample results show the majority of residual VOC contamination remains in Parcel 1 with lesser amounts in the other three parcels. Several VOCs, including tetrachloroethylene (PCE) and trichloroethylene (TCE), were detected. PCE was the major VOC with lesser amounts of TCE. Most soil gas concentrations of PCE ranged from 0 to 60 ppmv with one well (VEW-22A) as high as 200 ppmv. Air sparging (AS) generally involves the injection of air into the aquifer through either vertical or horizontal wells. AS is coupled with SVE systems when contaminant recovery is necessary. While traditional air sparging (AS) is not a primary component of the DUS process, following the cessation of steam injection, eight (8) of the sixty-three (63) steam injection wells were used to inject air. These wells were previously used for hydrous pyrolysis oxidation (HPO) as part of the DUS process. Air sparging is different from the HPO operations in that the air was injected at a higher rate (20 to 50 scfm) versus HPO (1 to 2 scfm). . At the DUS II site the air injection wells were tested to determine if air sparging affected

  10. Collecting Samples of Workplace Air. Module 8. Vocational Education Training in Environmental Health Sciences.

    ERIC Educational Resources Information Center

    Consumer Dynamics Inc., Rockville, MD.

    This module, one of 25 on vocational education training for careers in environmental health occupations, contains self-instructional materials on collecting samples of workplace air. Following guidelines for students and instructors and an introduction that explains what the student will learn are three lessons: (1) collecting information about…

  11. Air sampling and analysis in a rubber vulcanization area.

    PubMed

    Rappaport, S M; Fraser, D A

    1977-05-01

    Results of sampling and analysis of air in a rubber vulcanization area are described. Organic compounds were collected on activated charcoal, desorbed with carbon disulfide and analyzed by gas chromatography. Several previously identified substances were quantitated, including styrene, toluene, ethylbenzene, and several oligomers of 1,3-butadiene. Concentrations ranged from 0.007 to 1.1 ppm.

  12. Air sampling of mold spores by slit impactors: yield comparison.

    PubMed

    Pityn, Peter J; Anderson, James

    2013-01-01

    The performance of simple slit impactors for air sampling of mold contamination was compared under field conditions. Samples were collected side-by-side, outdoors in quadruplicates with Burkhard (ambient sampler) and Allergenco MK3 spore traps and with two identical Allergenco slit cassettes operated at diverse flow rates of 5 and 15 L/min, respectively. The number and types of mold spores in each sample were quantified by microscopy. Results showed all four single-stage slit impactors produced similar spore yields. Moreover, paired slit cassettes produced similar outcomes despite a three-fold difference in their sampling rate. No measurable difference in the amount or mix of mold spores per m(3)of air was detected. The implications for assessment of human exposures and interpretation of indoor/outdoor fungal burden are discussed. These findings demonstrate that slit cassettes capture most small spores, effectively and without bias, when operated at a range of flow rates including the lower flow rates used for personal sampling. Our findings indicate sampling data for mold spores correlate for different single stage impactor collection methodologies and that data quality is not deteriorated by operating conditions deviating from manufacturers' norms allowing such sampling results to be used for scientific, legal, investigative, or property insurance purposes. The same conclusion may not be applied to other particle sampling instruments and mulit-stage impactors used for ambient particulate sampling, which represent an entirely different scenario. This knowledge may help facilitate comparison between scientific studies where methodological differences exist.

  13. Recommended Immunological Assays to Screen for Ricin-Containing Samples.

    PubMed

    Simon, Stéphanie; Worbs, Sylvia; Avondet, Marc-André; Tracz, Dobryan M; Dano, Julie; Schmidt, Lisa; Volland, Hervé; Dorner, Brigitte G; Corbett, Cindi R

    2015-11-26

    Ricin, a toxin from the plant Ricinus communis, is one of the most toxic biological agents known. Due to its availability, toxicity, ease of production and absence of curative treatments, ricin has been classified by the Centers for Disease Control and Prevention (CDC) as category B biological weapon and it is scheduled as a List 1 compound in the Chemical Weapons Convention. An international proficiency test (PT) was conducted to evaluate detection and quantification capabilities of 17 expert laboratories. In this exercise one goal was to analyse the laboratories' capacity to detect and differentiate ricin and the less toxic, but highly homologuous protein R. communis agglutinin (RCA120). Six analytical strategies are presented in this paper based on immunological assays (four immunoenzymatic assays and two immunochromatographic tests). Using these immunological methods "dangerous" samples containing ricin and/or RCA120 were successfully identified. Based on different antibodies used the detection and quantification of ricin and RCA120 was successful. The ricin PT highlighted the performance of different immunological approaches that are exemplarily recommended for highly sensitive and precise quantification of ricin.

  14. Radiocarbon analysis of stratospheric CO2 retrieved from AirCore sampling

    NASA Astrophysics Data System (ADS)

    Paul, Dipayan; Chen, Huilin; Been, Henk A.; Kivi, Rigel; Meijer, Harro A. J.

    2016-10-01

    Radiocarbon (14C) is an important atmospheric tracer and one of the many used in the understanding of the global carbon budget, which includes the greenhouse gases CO2 and CH4. Measurement of radiocarbon in atmospheric CO2 generally requires the collection of large air samples (a few liters) from which CO2 is extracted and then the concentration of radiocarbon is determined using accelerator mass spectrometry (AMS). However, the regular collection of air samples from the stratosphere, for example using aircraft and balloons, is prohibitively expensive. Here we describe radiocarbon measurements in stratospheric CO2 collected by the AirCore sampling method. AirCore is an innovative atmospheric sampling system, which comprises a long tube descending from a high altitude with one end open and the other closed, and it has been demonstrated to be a reliable, cost-effective sampling system for high-altitude profile (up to ≈ 30 km) measurements of CH4 and CO2. In Europe, AirCore measurements have been being performed on a regular basis near Sodankylä (northern Finland) since September 2013. Here we describe the analysis of samples from two such AirCore flights made there in July 2014, for determining the radiocarbon concentration in stratospheric CO2. The two AirCore profiles were collected on consecutive days. The stratospheric part of the AirCore was divided into six sections, each containing ≈ 35 µg CO2 ( ≈ 9.6 µgC), and stored in a stratospheric air subsampler constructed from 1/4 in. coiled stainless steel tubing ( ≈ 3 m). A small-volume extraction system was constructed that enabled > 99.5 % CO2 extraction from the stratospheric air samples. Additionally, a new small-volume high-efficiency graphitization system was constructed for graphitization of these extracted CO2 samples, which were measured at the Groningen AMS facility. Since the stratospheric samples were very similar in mass, reference samples were also prepared in the same mass range for

  15. RAPID SEPARATION METHOD FOR ACTINIDES IN EMERGENCY AIR FILTER SAMPLES

    SciTech Connect

    Maxwell, S.; Noyes, G.; Culligan, B.

    2010-02-03

    A new rapid method for the determination of actinides and strontium in air filter samples has been developed at the Savannah River Site Environmental Lab (Aiken, SC, USA) that can be used in emergency response situations. The actinides and strontium in air filter method utilizes a rapid acid digestion method and a streamlined column separation process with stacked TEVA, TRU and Sr Resin cartridges. Vacuum box technology and rapid flow rates are used to reduce analytical time. Alpha emitters are prepared using cerium fluoride microprecipitation for counting by alpha spectrometry. The purified {sup 90}Sr fractions are mounted directly on planchets and counted by gas flow proportional counting. The method showed high chemical recoveries and effective removal of interferences. This new procedure was applied to emergency air filter samples received in the NRIP Emergency Response exercise administered by the National Institute for Standards and Technology (NIST) in April, 2009. The actinide and {sup 90}Sr in air filter results were reported in {approx}4 hours with excellent quality.

  16. Evaluation of membrane filter field monitors for microbiological air sampling

    NASA Technical Reports Server (NTRS)

    Fields, N. D.; Oxborrow, G. S.; Puleo, J. R.; Herring, C. M.

    1974-01-01

    Due to area constraints encountered in assembly and testing areas of spacecraft, the membrane filter field monitor (MF) and the National Aeronautics and Space Administration-accepted Reyniers slit air sampler were compared for recovery of airborne microbial contamination. The intramural air in a microbiological laboratory area and a clean room environment used for the assembly and testing of the Apollo spacecraft was studied. A significantly higher number of microorganisms was recovered by the Reyniers sampler. A high degree of consistency between the two sampling methods was shown by a regression analysis, with a correlation coefficient of 0.93. The MF samplers detected 79% of the concentration measured by the Reyniers slit samplers. The types of microorganisms identified from both sampling methods were similar.

  17. Balloon Operation for Stratospheric Air Sampling at Antarctica

    NASA Astrophysics Data System (ADS)

    Honda, H.; Yajima, N.; Yamagami, T.; Aoki, S.; Hashida, G.; Machida, T.; Morimoto, S.

    On January 3rd, 1998, a cryogenic air sampling experiment was carried out at Syowa Station (69S, 40E), which is the first successful trial in the world for collection of large amount of stratospheric air over the Antarctic. The samples are analyzed for CO2, CH4, CFCs, and C and O isotope ratios in CO2 in the laboratories. As the meteorological conditions for launching and payload recovery are both critical, feasibility on wind conditions over Syowa Station was studied in detail. The balloon launching operations had to be performed without a specialist. Facilities for balloon launching, tracking, and other support systems were newly designed for ready-to- and easy-to-use. Realtime remote support from Japan for the balloon launching and flight control operations was applied using a computer network linked by INMARSAT

  18. Can car air filters be useful as a sampling medium for air pollution monitoring purposes?

    PubMed

    Katsoyiannis, Athanasios; Birgul, Askin; Ratola, Nuno; Cincinelli, Alessandra; Sweetman, Andy J; Jones, Kevin C

    2012-11-01

    Urban air quality and real human exposure to chemical environmental stressors is an issue of high scientific and political interest. In an effort to find innovative and inexpensive means for air quality monitoring, the ability of car engine air filters (CAFs) to act as efficient samplers collecting street level air, to which people are exposed to, was tested. In particular, in the case of taxis, air filters are replaced after regular distances, the itineraries are almost exclusively urban, cruising mode is similar and, thus, knowledge of the air flow can provide with an integrated city air sample. The present pilot study focused on polycyclic aromatic hydrocarbons (PAHs), the most important category of organic pollutants associated with traffic emissions. Concentrations of ΣPAHs in CAFs ranged between 650 and 2900 μg CAF(-1), with benzo[b]fluoranthene, benzo[k]fluoranthene and indeno[123-cd]pyrene being the most abundant PAHs. Benzo[a]pyrene (BaP) ranged between 110 and 250 μg CAF(-1), accounting regularly for 5-15% of the total carcinogenic PAHs. The CAF PAH loads were used to derive road-level atmospheric PAH concentrations from a standard formula relating to the CAF air flow. Important parameters/assumptions for these estimates are the cruising speed and the exposure duration of each CAF. Based on information obtained from the garage experts, an average 'sampled air volume' of 48,750 m(3) per CAF was estimated, with uncertainty in this calculation estimated to be about a factor of 4 between the two extreme scenarios. Based on this air volume, ΣPAHs ranged between 13 and 56 ng m(-3) and BaP between 2.1 and 5.0 ng m(-3), suggesting that in-traffic BaP concentrations can be many times higher than the limit values set by the UK (0.25 ng m(-3)) and the European Union (1.0 ng m(-3)), or from active sampling stations normally cited on building roof tops or far from city centres. Notwithstanding the limitations of this approach, the very low cost, the continuous

  19. Air Sampling Data for BP Spill/Deepwater Horizon

    EPA Pesticide Factsheets

    The Deepwater Horizon oil spill (also referred to as the BP oil spill) began on 20 April 2010 in the Gulf of Mexico on the BP-operated Macondo Prospect. Following the explosion and sinking of the Deepwater Horizon oil rig, a sea-floor oil gusher flowed for 87 days, until it was capped on 15 July 2010.In response to the BP oil spill, EPA sampled air, water, sediment, and waste generated by the cleanup operations.

  20. Toxicological Assessment of ISS Air Quality: Contingency Sampling - February 2013

    NASA Technical Reports Server (NTRS)

    Meyers, Valerie

    2013-01-01

    Two grab sample containers (GSCs) were collected by crew members onboard ISS in response to a vinegar-like odor in the US Lab. On February 5, the first sample was collected approximately 1 hour after the odor was noted by the crew in the forward portion of the Lab. The second sample was collected on February 22 when a similar odor was noted and localized to the end ports of the microgravity science glovebox (MSG). The crewmember removed a glove from the MSG and collected the GSC inside the glovebox volume. Both samples were returned on SpaceX-2 for ground analysis.

  1. Determination of radiocarbon in stratospheric CO2, obtained through AirCore sampling.

    NASA Astrophysics Data System (ADS)

    Paul, Dipayan; Chen, Huilin; Been, Henk A.; Kivi, Rigel; Meijer, Harro A. J.

    2016-04-01

    The concentration of Greenhouse Gases (GHG), with carbon dioxide as the most prominent example, has been and still is increasing, predominantly due to emissions from fossil fuel combustion. CO2 is also the most important component of the global carbon cycle. Among other tracers, radiocarbon (Carbon-14) is a unique and an important atmospheric tracer used in the understanding of the global carbon cycle. Radiocarbon is a naturally occurring isotope (radioactive, t 1/2 = 5730 ± 40 years) of carbon produced through the interaction of thermalized neutrons and nitrogen in the upper atmosphere. Generally, for performing atmospheric radiocarbon measurements in the higher atmosphere, large samples (few liters of air) were collected using aircrafts and balloons. However, collecting stratospheric samples on a regular basis for radiocarbon analysis is extremely expensive. Here we describe the determination of radiocarbon concentrations in stratospheric CO2, collected using AirCore sampling. AirCore is an innovative sampling technique for obtaining vertical atmospheric profiles and, in Europe, is done on a regular basis at Sodankylä, Finland for CO2, CH4 and CO. The stratospheric parts of two such AirCore profiles were used in this study as a proof-of-principle. CO2 from the stratospheric air samples were extracted and converted to elemental carbon, which were then measured at the Accelerator Mass Spectrometric (AMS) facility of the Centre for Isotope Research (CIO) at the University of Groningen. The stratospheric part of the AirCore profile was divided into six sections, each contained approximately 10 μg C. A detailed description of the extraction, graphitization, AMS analysis and the derivation of the stratospheric radiocarbon profile will be the main focus. Through our results, we will show that AirCore is a viable sampling method for performing high-precision radiocarbon measurements of stratospheric CO2 with reasonably good spatial resolution on a regular basis

  2. Artifact peroxides produced during cryogenic sampling of ambient air

    NASA Astrophysics Data System (ADS)

    Staffelbach, Thomas; Neftel, Albrecht; Dasgupta, Purnendu K.

    Peroxides were found to be produced as artifacts during cryogenic sampling with Horibe traps. Cryogenic trap sampling was compared to collection with a wet effluent diffusion denuder and a Nafion membrane diffusion denuder. Hydrogen peroxide and hydroxymethyl hydroperoxide measured in the cryogenic trap samples were significantly higher. In comparison, no evidence of artifact methyl hydroperoxide production was found. The amount of artifact H2O2 and HMHP produced increased with decreasing trap temperature. Spiking ambient air with ethene or isoprene showed that these hydrocarbons, in the presence of ozone, can be responsible for the artifact production of peroxides. Our results clearly suggest that the peroxide data obtained by cryogenic sampling and reported in the literature should be interpreted with caution.

  3. Monitoring airborne fungal spores in an experimental indoor environment to evaluate sampling methods and the effects of human activity on air sampling.

    PubMed Central

    Buttner, M P; Stetzenbach, L D

    1993-01-01

    Aerobiological monitoring was conducted in an experimental room to aid in the development of standardized sampling protocols for airborne microorganisms in the indoor environment. The objectives of this research were to evaluate the relative efficiencies of selected sampling methods for the retrieval of airborne fungal spores and to determine the effect of human activity on air sampling. Dry aerosols containing known concentrations of Penicillium chrysogenum spores were generated, and air samples were taken by using Andersen six-stage, Surface Air System, Burkard, and depositional samplers. The Andersen and Burkard samplers retrieved the highest numbers of spores compared with the measurement standard, an aerodynamic particle sizer located inside the room. Data from paired samplers demonstrated that the Andersen sampler had the highest levels of sensitivity and repeatability. With a carpet as the source of P. chrysogenum spores, the effects of human activity (walking or vacuuming near the sampling site) on air sampling were also examined. Air samples were taken under undisturbed conditions and after human activity in the room. Human activity resulted in retrieval of significantly higher concentrations of airborne spores. Surface sampling of the carpet revealed moderate to heavy contamination despite relatively low airborne counts. Therefore, in certain situations, air sampling without concomitant surface sampling may not adequately reflect the level of microbial contamination in indoor environments. PMID:8439150

  4. Radiological background levels found on glass fiber filters used for low-level environmental surveillance air sampling

    SciTech Connect

    Althouse, P. E.

    1998-09-16

    Environmental surveillance of low-level radioactive particles in air requires a thorough understanding of low-level techniques and air sample collection media. High-volume air sampling for radioactive particles around Lawrence Livermore National Laboratory (LLNL) employs glass-fiber filters that are analyzed for gross alpha and gross beta activity and for specific isotopes. This study was conducted to determine the activities of radionuclides contained in blank glass-fiber filters. Data from this study provided a partial explanation of differences between current reported concentrations of radionuclides in air and those reported historically when cellulose filters were used in the LLNL monitoring effort.

  5. Sampling intercomparisons for aldehydes in simulated workplace air.

    PubMed

    Goelen, E; Lambrechts, M; Geyskens, F

    1997-05-01

    Thirty one laboratories of various EU Member States have participated in two interlaboratory comparisons in order to assess errors of personal sampling methods associated with both the sampling and the analytical steps. In contrast to conventional quality control schemes, this project particularly focuses attention on the sampling and identification step; it is executed by means of sampling exercises and has included discussions on potential sources of error. In a sampling exercise, participants come to a central facility and perform measurements on synthetic workplace air in a laboratory installation. Concentration levels of formaldehyde, acrolein, glutaraldehyde and acetaldehyde between 0.1 and 2 times the limit value for workplace air were prepared at various humidity levels and with acetone, occasionally, as interferent. Sampling times varied from 1-4 h. The related analytical work is performed at the analyst's own laboratory. The intention is for each participant to determine the observed value of the delivered standard atmosphere using the sampling method of his own choice. Trueness (bias), precision and relative overall uncertainty of each method-laboratory combination is calculated and verified towards compliance with EN 482, which outlines minimum performance criteria. The first challenge involved the precise gas phase generation of the selected analytes in high air flows (up to 300 1 min-1) and calculating the true value only by direct reference to primary standards. This was accomplished by modifying the capillary dosage injection technique so that reactive compounds, like low molecular mass aldehydes, could be dosed with the same accuracy and precision as unreactive solvents. A permeation tube with high emission rate was developed for formaldehyde. Up to ten different sampling techniques were evaluated. The measurement methods used by the majority of the participants were based on pumped sampling on silica cartridges (or tubes) and glass fiber filters

  6. Evaluation of official air sampling methodologies in Ukraine

    SciTech Connect

    Nakonechniy, J.J.; Wadden, R.A.; Scheff, P.A.; Suero, M.

    1997-12-31

    In conjunction with an environmental epidemiology study of the health of Ukrainian children, a significant amount of air pollution measurement data was gathered from government agencies. The areas of interest were the industrial city of Dneprodzherzhinsk; and the Dniprovsky region of Kyiv. The data were for 1993 and, for some of the monitoring stations, 1994. The pollutants reported included dust (approximately equivalent to TSP, total suspended particulate matter), SO{sub 2}, CO, NO{sub 2}, NO, H{sub 2}S, phenol, HCl, NH{sub 3}, formaldehyde, BaP, and lead. The ultimate goal was to evaluate whether existing historical data are appropriate for developing measures of human exposure. In order to evaluate the data it was necessary to understand the sampling and analytical methodologies which were used. Small sample volumes coupled with dated analytical procedures resulted in very poor precision and detection limits for most of the measured pollutants. The measurement of particulate matter is a good example of the limits imposed by the sampling methodology. The short sample time (20 min), small sample volume (150 lpm), and limited analytical balances (0.5 mg resolution) result in a minimum lower limit of detection of 0.25 mg/m{sup 3}. For example at Kyiv Station 3 in 1993, only one of 545 measurements exceeded 0.2 mg/m{sup 3}. This minimum detectable quantity is over three times the former US annual TSP standard. In addition, even when operated on a 24-hour basis in the US, it has been shown that the sampling method only collected approximately 34% of that collected by a co-located hi-vol sampler. Consequently, official air pollution data for suspended dust are likely to severely under-represent actual ambient concentrations. Data for other pollutants are presented and sampling and analytical methods are similarly compared with Western methods in common use.

  7. Passive air sampling of gaseous elemental mercury: a critical review

    NASA Astrophysics Data System (ADS)

    McLagan, David S.; Mazur, Maxwell E. E.; Mitchell, Carl P. J.; Wania, Frank

    2016-03-01

    Because gaseous elemental mercury (GEM) is distributed globally through the atmosphere, reliable means of measuring its concentrations in air are important. Passive air samplers (PASs), designed to be cheap, simple to operate, and to work without electricity, could provide an alternative to established active sampling techniques in applications such as (1) long-term monitoring of atmospheric GEM levels in remote regions and in developing countries, (2) atmospheric mercury source identification and characterization through finely resolved spatial mapping, and (3) the recording of personal exposure to GEM. An effective GEM PAS requires a tightly constrained sampling rate, a large and stable uptake capacity, and a sensitive analytical technique. None of the GEM PASs developed to date achieve levels of accuracy and precision sufficient for the reliable determination of background concentrations over extended deployments. This is due to (1) sampling rates that vary due to meteorological factors and manufacturing inconsistencies, and/or (2) an often low, irreproducible and/or unstable uptake capacity of the employed sorbents. While we identify shortcomings of existing GEM PAS, we also reveal potential routes to overcome those difficulties. Activated carbon and nanostructured metal surfaces hold promise as effective sorbents. Sampler designs incorporating diffusive barriers should be able to notably reduce the influence of wind on sampling rates.

  8. Passive air sampling of gaseous elemental mercury: a critical review

    NASA Astrophysics Data System (ADS)

    McLagan, D. S.; Mazur, M. E. E.; Mitchell, C. P. J.; Wania, F.

    2015-12-01

    Because gaseous elemental mercury (GEM) is distributed globally through the atmosphere, reliable means of measuring its concentrations in air are important. Passive air samplers (PASs), designed to be cheap, simple to operate, and to work without electricity, could provide an alternative to established active sampling techniques in applications such as (1) long term monitoring of atmospheric GEM levels in remote regions and in developing countries, (2) atmospheric mercury source identification and characterisation through finely-resolved spatial mapping, and (3) the recording of personal exposure to GEM. An effective GEM PAS requires a tightly constrained sampling rate, a large and stable uptake capacity, and a sensitive analytical technique. None of the GEM PASs developed to date achieves levels of accuracy and precision sufficient for the reliable determination of background concentrations over extended deployments. This is due to (1) sampling rates that vary due to meteorological factors and manufacturing inconsistencies and/or (2) an often low, irreproducible and/or unstable uptake capacity of the employed sorbents. While we identify shortcomings of existing GEM PAS, we also reveal potential routes to overcome those difficulties. Activated carbon and nano-structured metal surfaces hold promise as effective sorbents. Sampler designs incorporating diffusive barriers should be able to notably reduce the influence of wind on sampling rates.

  9. Soyuz 22 Return Samples: Assessment of Air Quality Aboard the International Space Station

    NASA Technical Reports Server (NTRS)

    Jams, John T.

    2010-01-01

    Three mini-grab sample containers (m-GSCs) were returned aboard Soyuz 22 because of concerns that new air pollutants were present in the air and these were getting into the water recovery system. The Total Organic Carbon Analyzer had been giving increasing readings of total organic carbon (TOC) in the potable water, and it was postulated that an increased load into the system was responsible. The toxicological assessment of 3 m-GSCs from the ISS is shown in Table 1. The recoveries of the 3 standards (as listed above) from the GSCs averaged 103, 95 and 76%, respectively. Recovery from formaldehyde control badges were 90 and 91%.

  10. Chemical transformations during ambient air sampling for organic vapors

    SciTech Connect

    Pellizzari, E.D.; Drost, K.J.

    1984-09-01

    Potential chemical transformations of olefins in the presence of ozone and high levels (ppm) of halogens (Cl/sub 2/, Br/sub 2/) were demonstrated when sampling ambient air with a sorbent cartridge. The use of stryene-d/sub 8/ and cyclohexene-d/sub 10/ spiked sampling devices and capillary gas chromatography/mass spectrometry (GC/MS) analysis allowed the detection and identification of several deuteriated oxidation and halogenated products. Dimethylamine-d/sub 6/ was converted in trace quantities (5-10 mg) to dimethylnitrosamine-d/sub 6/ when sampling was conducted in the presence of NO/sub x/. Oxidation reactions were prevented when filters (2.5 cm) employed for removing particulates were impregnated with 5-10 mg of sodium thiosulfate and placed in front of the sorbent cartridge. Halogenation reactions were also consideraly reduced.

  11. Implementation of Fowler's method for end-tidal air sampling.

    PubMed

    Di Francesco, F; Loccioni, C; Fioravanti, M; Russo, A; Pioggia, G; Ferro, M; Roehrer, I; Tabucchi, S; Onor, M

    2008-09-01

    The design, realization and testing of a CO(2)-triggered breath sampler, capable of a separate collection of dead space and end-tidal air on multiple breaths, is presented. This sampling procedure has advantages in terms of the sample volume, insights regarding the origin of compounds, increased reproducibility and higher concentrations of compounds. The high quality of design and the speed of the components ensure a breath-by-breath estimate of dead volume, as well as the comfort and safety of the subject under test. The system represents a valid tool to contribute to the development of a standardized sampling protocol needed to compare results obtained by the various groups in this field.

  12. Chemical reactivities of ambient air samples in three Southern California communities

    PubMed Central

    Eiguren-Fernandez, Arantza; Di Stefano, Emma; Schmitz, Debra A.; Guarieiro, Aline Lefol Nani; Salinas, Erika M.; Nasser, Elina; Froines, John R.; Cho, Arthur K.

    2015-01-01

    The potential adverse health effects of PM2.5 and vapor samples from three communities that neighbor railyards, Commerce (CM), Long Beach (LB), and San Bernardino (SB), were assessed by determination of chemical reactivities attributed to the induction of oxidative stress by air pollutants. The assays used were dithiothreitol (DTT) and dihydrobenzoic acid (DHBA) based procedures for prooxidant content and a glyceraldehyde-3-phosphate dehydrogenase (GAPDH) assay for electrophiles. Prooxidants and electrophiles have been proposed as the reactive chemical species responsible for the induction of oxidative stress by air pollution mixtures. The PM2.5 samples from CM and LB sites showed seasonal differences in reactivities with higher levels in the winter whereas the SB sample differences were reversed. The reactivities in the vapor samples were all very similar, except for the summer SB samples, which contained higher levels of both prooxidants and electrophiles. The results suggest the observed reactivities reflect general geographical differences rather than direct effects of the railyards. Distributional differences in reactivities were also observed with PM2.5 fractions containing most of the prooxidants (74–81%) and the vapor phase most of the electrophiles (82–96%). The high levels of the vapor phase electrophiles and their potential for adverse biological effects point out the importance of the vapor phase in assessing the potential health effects of ambient air. PMID:25947123

  13. Air-sampling inlet contamination by aircraft emissions on the NASA CV-990 aircraft

    NASA Technical Reports Server (NTRS)

    Condon, E. P.; Vedder, J. F.

    1984-01-01

    Results of an experimental investigation of the contamination of air sampling inlets by aircraft emissions from the NASA CV-990 research aircraft are presented. This four-engine jet aircraft is a NASA facility used for many different atmospheric and meteorological experiments, as well as for developing spacecraft instrumentation for remote measurements. Our investigations were performed to provide information on which to base the selection of sampling locations for a series of multi-instrument missions for measuring tropospheric trace gases. The major source of contamination is the exhaust from the jet engines, which generate many of the same gases that are of interest in atmospheric chemistry, as well as other gases that may interfere with sampling measurements. The engine exhaust contains these gases in mixing ratios many orders of magnitude greater than those that occur in the clean atmosphere which the missions seek to quantify. Pressurized samples of air were collected simultaneously from a scoop located forward of the engines to represent clean air and from other multiport scoops at various aft positions on the aircraft. The air samples were analyzed in the laboratory by gas chromatography for carbon monoxide, an abundant combustion by-product. Data are presented for various scoop locations under various flight conditions.

  14. STS-65 Commander Cabana and PLC Hieb take air sample at IML-2 Rack 7 NIZEMI

    NASA Technical Reports Server (NTRS)

    1994-01-01

    STS-65 Commander Robert D. Cabana (right) and Payload Commander (PLC) Richard J. Hieb take an air sample inside the International Microgravity Laboratory 2 (IML-2) spacelab science module. The two crewmembers are in front of Rack 7 which contains the large isothermal furnace (LIF) and slow rotating centrifuge microscope (NIZEMI). The photo was among the first group released by NASA following the two-week IML-2 mission aboard the Space Shuttle Columbia, Orbiter Vehicle (OV) 102.

  15. Interferometrically stable, enclosed, spinning sample cell for spectroscopic experiments on air-sensitive samples

    NASA Astrophysics Data System (ADS)

    Baranov, Dmitry; Hill, Robert J.; Ryu, Jisu; Park, Samuel D.; Huerta-Viga, Adriana; Carollo, Alexa R.; Jonas, David M.

    2017-01-01

    In experiments with high photon flux, it is necessary to rapidly remove the sample from the beam and to delay re-excitation until the sample has returned to equilibrium. Rapid and complete sample exchange has been a challenge for air-sensitive samples and for vibration-sensitive experiments. Here, a compact spinning sample cell for air and moisture sensitive liquid and thin film samples is described. The principal parts of the cell are a copper gasket sealed enclosure, a 2.5 in. hard disk drive motor, and a reusable, chemically inert glass sandwich cell. The enclosure provides an oxygen and water free environment at the 1 ppm level, as demonstrated by multi-day tests with sodium benzophenone ketyl radical. Inside the enclosure, the glass sandwich cell spins at ≈70 Hz to generate tangential speeds of 7-12 m/s that enable complete sample exchange at 100 kHz repetition rates. The spinning cell is acoustically silent and compatible with a ±1 nm rms displacement stability interferometer. In order to enable the use of the spinning cell, we discuss centrifugation and how to prevent it, introduce the cycle-averaged resampling rate to characterize repetitive excitation, and develop a figure of merit for a long-lived photoproduct buildup.

  16. Interferometrically stable, enclosed, spinning sample cell for spectroscopic experiments on air-sensitive samples.

    PubMed

    Baranov, Dmitry; Hill, Robert J; Ryu, Jisu; Park, Samuel D; Huerta-Viga, Adriana; Carollo, Alexa R; Jonas, David M

    2017-01-01

    In experiments with high photon flux, it is necessary to rapidly remove the sample from the beam and to delay re-excitation until the sample has returned to equilibrium. Rapid and complete sample exchange has been a challenge for air-sensitive samples and for vibration-sensitive experiments. Here, a compact spinning sample cell for air and moisture sensitive liquid and thin film samples is described. The principal parts of the cell are a copper gasket sealed enclosure, a 2.5 in. hard disk drive motor, and a reusable, chemically inert glass sandwich cell. The enclosure provides an oxygen and water free environment at the 1 ppm level, as demonstrated by multi-day tests with sodium benzophenone ketyl radical. Inside the enclosure, the glass sandwich cell spins at ≈70 Hz to generate tangential speeds of 7-12 m/s that enable complete sample exchange at 100 kHz repetition rates. The spinning cell is acoustically silent and compatible with a ±1 nm rms displacement stability interferometer. In order to enable the use of the spinning cell, we discuss centrifugation and how to prevent it, introduce the cycle-averaged resampling rate to characterize repetitive excitation, and develop a figure of merit for a long-lived photoproduct buildup.

  17. Axially perpendicular offset Raman scheme for reproducible measurement of housed samples in a noncircular container under variation of container orientation.

    PubMed

    Duy, Pham K; Chang, Kyeol; Sriphong, Lawan; Chung, Hoeil

    2015-03-17

    An axially perpendicular offset (APO) scheme that is able to directly acquire reproducible Raman spectra of samples contained in an oval container under variation of container orientation has been demonstrated. This scheme utilized an axially perpendicular geometry between the laser illumination and the Raman photon detection, namely, irradiation through a sidewall of the container and gathering of the Raman photon just beneath the container. In the case of either backscattering or transmission measurements, Raman sampling volumes for an internal sample vary when the orientation of an oval container changes; therefore, the Raman intensities of acquired spectra are inconsistent. The generated Raman photons traverse the same bottom of the container in the APO scheme; the Raman sampling volumes can be relatively more consistent under the same situation. For evaluation, the backscattering, transmission, and APO schemes were simultaneously employed to measure alcohol gel samples contained in an oval polypropylene container at five different orientations and then the accuracies of the determination of the alcohol concentrations were compared. The APO scheme provided the most reproducible spectra, yielding the best accuracy when the axial offset distance was 10 mm. Monte Carlo simulations were performed to study the characteristics of photon propagation in the APO scheme and to explain the origin of the optimal offset distance that was observed. In addition, the utility of the APO scheme was further demonstrated by analyzing samples in a circular glass container.

  18. Evaluation of Urban Air Quality By Passive Sampling Technique

    NASA Astrophysics Data System (ADS)

    Nunes, T. V.; Miranda, A. I.; Duarte, S.; Lima, M. J.

    Aveiro is a flat small city in the centre of Portugal, close to the Atlantic coast. In the last two decades an intensive development of demographic, traffic and industry growth in the region was observed which was reflected on the air quality degrada- tion. In order to evaluate the urban air quality in Aveiro, a field-monitoring network by passive sampling with high space resolution was implemented. Twenty-four field places were distributed in a area of 3x3 Km2 and ozone and NO2 concentrations were measured. The site distribution density was higher in the centre, 250x250 m2 than in periphery where a 500x500 m2 grid was used. The selection of field places took into consideration the choice criteria recommendation by United Kingdom environmental authorities, and three tubes and a blank tube for each pollutant were used at each site. The sampling system was mounted at 3m from the ground usually profiting the street lampposts. Concerning NO2 acrylic tubes were used with 85 mm of length and an in- ternal diameter of 12mm, where in one of the extremities three steel grids impregnated with a solution of TEA were placed and fixed with a polyethylene end cup (Heal et al., 1999); PFA Teflon tube with 53 mm of length and 9 mm of internal diameter and three impregnated glass filters impregnated with DPE solution fixed by a teflon end cup was used for ozone sampling (Monn and Hargartner, 1990). The passive sampling method for ozone and nitrogen dioxide was compared with continuous measurements, but the amount of measurements wasnSt enough for an accurate calibration and validation of the method. Although this constraint the field observations (June to August 2001) for these two pollutants assign interesting information about the air quality in the urban area. A krigger method of interpolation (Surfer- Golden Software-2000) was applied to field data to obtain isolines distribution of NO2 and ozone concentration for the studied area. Even the used passive sampling method has many

  19. Ozone measurement system for NASA global air sampling program

    NASA Technical Reports Server (NTRS)

    Tiefermann, M. W.

    1979-01-01

    The ozone measurement system used in the NASA Global Air Sampling Program is described. The system uses a commercially available ozone concentration monitor that was modified and repackaged so as to operate unattended in an aircraft environment. The modifications required for aircraft use are described along with the calibration techniques, the measurement of ozone loss in the sample lines, and the operating procedures that were developed for use in the program. Based on calibrations with JPL's 5-meter ultraviolet photometer, all previously published GASP ozone data are biased high by 9 percent. A system error analysis showed that the total system measurement random error is from 3 to 8 percent of reading (depending on the pump diaphragm material) or 3 ppbv, whichever are greater.

  20. Measured phenol concentrations in air and rain water samples collected near a wood preserving facility

    SciTech Connect

    Allen, S.K.; Allen, C.W.

    1995-12-31

    Phenol concentrations were determined in air and rain water samples collected downwind from a coal tar creosote wood preserving facility in Terre Haute, IN. Coal tar creosote is known to contain a large number of constituents and is composed chiefly of polycyclic aromatic hydrocarbons (PAH), phenols, and N-, S-, and O-heterocycles. Phenol was chosen as a marker compound for coal tar creosote emissions because it is present at a large mole fraction in coal tar creosote. Phenol was determined by HPLC with UV-Visible detection. Phenol in collected rain water samples was determined directly by HPLC after acidification and filtration. Phenol concentrations in collected air samples ranged from 4.1 to 15.7 {micro}g/m3 while rain water concentrations ranged from 7.9 to 28.2 {micro}g/L. Using a value for the thermodynamic Henry`s law constant of K{sub H} = 4.5 {times} 10{sup {minus}4} L atm/mole at 20 C for phenol and measured gas-phase phenol concentrations, even higher rain water concentrations would be expected if equilibrium was established. This indicates that the amount of phenol present in the air parcels sampled exceeded the amount that could be scavenged by rain drops under the conditions prevailing at the time of sampling. The values for phenol concentrations reported here are roughly two orders of magnitude higher than results from previous studies where phenol concentrations in air and rain water samples collected in urban areas were reported. It is likely that other more toxic constituents of coal tar creosote are also present at high concentrations in air parcels that receive emissions from wood treatment facilities.

  1. 32 CFR 806.27 - Samples of Air Force FOIA processing documents.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 6 2012-07-01 2012-07-01 false Samples of Air Force FOIA processing documents. 806.27 Section 806.27 National Defense Department of Defense (Continued) DEPARTMENT OF THE AIR FORCE ADMINISTRATION AIR FORCE FREEDOM OF INFORMATION ACT PROGRAM § 806.27 Samples of Air Force FOIA...

  2. 32 CFR 806.27 - Samples of Air Force FOIA processing documents.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 6 2014-07-01 2014-07-01 false Samples of Air Force FOIA processing documents. 806.27 Section 806.27 National Defense Department of Defense (Continued) DEPARTMENT OF THE AIR FORCE ADMINISTRATION AIR FORCE FREEDOM OF INFORMATION ACT PROGRAM § 806.27 Samples of Air Force FOIA...

  3. 32 CFR 806.27 - Samples of Air Force FOIA processing documents.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 6 2013-07-01 2013-07-01 false Samples of Air Force FOIA processing documents. 806.27 Section 806.27 National Defense Department of Defense (Continued) DEPARTMENT OF THE AIR FORCE ADMINISTRATION AIR FORCE FREEDOM OF INFORMATION ACT PROGRAM § 806.27 Samples of Air Force FOIA...

  4. High-throughput liquid-absorption air-sampling apparatus and methods

    DOEpatents

    Zaromb, Solomon

    2000-01-01

    A portable high-throughput liquid-absorption air sampler [PHTLAAS] has an asymmetric air inlet through which air is drawn upward by a small and light-weight centrifugal fan driven by a direct current motor that can be powered by a battery. The air inlet is so configured as to impart both rotational and downward components of motion to the sampled air near said inlet. The PHTLAAS comprises a glass tube of relatively small size through which air passes at a high rate in a swirling, highly turbulent motion, which facilitates rapid transfer of vapors and particulates to a liquid film covering the inner walls of the tube. The pressure drop through the glass tube is <10 cm of water, usually <5 cm of water. The sampler's collection efficiency is usually >20% for vapors or airborne particulates in the 2-3.mu. range and >50% for particles larger than 4.mu.. In conjunction with various analyzers, the PHTLAAS can serve to monitor a variety of hazardous or illicit airborne substances, such as lead-containing particulates, tritiated water vapor, biological aerosols, or traces of concealed drugs or explosives.

  5. Bifunctional air electrodes containing elemental iron powder charging additive

    DOEpatents

    Liu, Chia-tsun; Demczyk, Brian G.; Gongaware, Paul R.

    1982-01-01

    A bifunctional air electrode for use in electrochemical energy cells is made, comprising a hydrophilic layer and a hydrophobic layer, where the hydrophilic layer essentially comprises a hydrophilic composite which includes: (i) carbon; (ii) elemental iron particles having a particle size of between about 25 microns and about 700 microns diameter; (iii) an oxygen evolution material; (iv) a nonwetting agent; and (v) a catalyst, where at least one current collector is formed into said composite.

  6. Development and Performance Evaluation of an Ozone-Contained Ice Making Machine Employing Pressurized Air Tight Containers

    NASA Astrophysics Data System (ADS)

    Yoshimura, Kenji; Akiyama, Tomoaki; Hirofuji, Yushi; Koyama, Shigeru

    Ozone has the capability of sterilization and deodorization due to high oxidation power. It is also effective for the conservation of perishable foods and purification of water. However, ozone has a disadvantage, that is, conservation of ozone is difficult because it reacts to oxygen. Recently, ozone-contained ice is taken attention for the purpose of its conservation. The use of ozone-contained ice seems to keep food fresher when we conserve and transport perishable foods due to the effects of cooling and sterilization of ozone-contained ice. In the present study, we have developed an ozone-contained ice making machine employing pressurized air tight containers with commercially available size. And the performance evaluation of the system is also carried out. Furthermore, we investigated the sterilization effect of ozone-contained ice on conservation of fish. It was seen that ozone-contained ice is effective for sterilization of surface of fish.

  7. Sorbent-based sampling methods for volatile and semi-volatile organic compounds in air Part 1: Sorbent-based air monitoring options.

    PubMed

    Woolfenden, Elizabeth

    2010-04-16

    Sorbent tubes/traps are widely used in combination with gas chromatographic (GC) analytical methods to monitor the vapour-phase fraction of organic compounds in air. Target compounds range in volatility from acetylene and freons to phthalates and PCBs and include apolar, polar and reactive species. Airborne vapour concentrations will vary depending on the nature of the location, nearby pollution sources, weather conditions, etc. Levels can range from low percent concentrations in stack and vent emissions to low part per trillion (ppt) levels in ultra-clean outdoor locations. Hundreds, even thousands of different compounds may be present in any given atmosphere. GC is commonly used in combination with mass spectrometry (MS) detection especially for environmental monitoring or for screening uncharacterised workplace atmospheres. Given the complexity and variability of organic vapours in air, no one sampling approach suits every monitoring scenario. A variety of different sampling strategies and sorbent media have been developed to address specific applications. Key sorbent-based examples include: active (pumped) sampling onto tubes packed with one or more sorbents held at ambient temperature; diffusive (passive) sampling onto sorbent tubes/cartridges; on-line sampling of air/gas streams into cooled sorbent traps; and transfer of air samples from containers (canisters, Tedlar) bags, etc.) into cooled sorbent focusing traps. Whichever sampling approach is selected, subsequent analysis almost always involves either solvent extraction or thermal desorption (TD) prior to GC(/MS) analysis. The overall performance of the air monitoring method will depend heavily on appropriate selection of key sampling and analytical parameters. This comprehensive review of air monitoring using sorbent tubes/traps is divided into 2 parts. (1) Sorbent-based air sampling option. (2) Sorbent selection and other aspects of optimizing sorbent-based air monitoring methods. The paper presents

  8. Direct high-resolution alpha spectrometry from nuclear fuel particles in an outdoor air sample.

    PubMed

    Pöllänen, R; Siiskonen, T

    2008-01-01

    The potential use of direct high-resolution alpha spectrometry to identify the presence of transactinium elements in air samples is illustrated in the case when alpha-particle-emitting radionuclides are incorporated in nuclear fuel particles. Alpha particle energy spectra are generated through Monte Carlo simulations assuming a nuclide composition similar to RBMK (Chernobyl) nuclear fuel. The major alpha-particle-emitting radionuclides, in terms of activity, are 242Cm, 239Pu and 240Pu. The characteristics of the alpha peaks are determined by fuel particle properties as well as the type of the air filter. It is shown that direct alpha spectrometry can be readily applied to membrane filter samples containing nuclear fuel particles when rapid nuclide identification is of relevance. However, the development of a novel spectrum analysis code is a prerequisite for unfolding complex alpha spectra.

  9. Wide Area Recovery and Resilency Program (WARRP). Video - Aggressive Air Sampling for B. anthracis Spores

    DTIC Science & Technology

    2012-09-14

    34Systematic Evaluation of Aggressive Air Sampling for Bacillus anthracis Spores", in which aggressive air sampling, used for asbestos fiber detection, was...Sep 2012 Final 01 Feb 2011 - 01 Sep 2012 Wide Area Recovery and Resiliency Program (WARRP) Video - Aggressive Air Sampling for B. anthracis Spores

  10. Data Quality Objectives for Regulatory Requirements for Hazardous and Radioactive Air Emissions Sampling and Analysis

    SciTech Connect

    MULKEY, C.H.

    1999-07-06

    This document describes the results of the data quality objective (DQO) process undertaken to define data needs for state and federal requirements associated with toxic, hazardous, and/or radiological air emissions under the jurisdiction of the River Protection Project (RPP). Hereafter, this document is referred to as the Air DQO. The primary drivers for characterization under this DQO are the regulatory requirements pursuant to Washington State regulations, that may require sampling and analysis. The federal regulations concerning air emissions are incorporated into the Washington State regulations. Data needs exist for nonradioactive and radioactive waste constituents and characteristics as identified through the DQO process described in this document. The purpose is to identify current data needs for complying with regulatory drivers for the measurement of air emissions from RPP facilities in support of air permitting. These drivers include best management practices; similar analyses may have more than one regulatory driver. This document should not be used for determining overall compliance with regulations because the regulations are in constant change, and this document may not reflect the latest regulatory requirements. Regulatory requirements are also expected to change as various permits are issued. Data needs require samples for both radionuclides and nonradionuclide analytes of air emissions from tanks and stored waste containers. The collection of data is to support environmental permitting and compliance, not for health and safety issues. This document does not address health or safety regulations or requirements (those of the Occupational Safety and Health Administration or the National Institute of Occupational Safety and Health) or continuous emission monitoring systems. This DQO is applicable to all equipment, facilities, and operations under the jurisdiction of RPP that emit or have the potential to emit regulated air pollutants.

  11. An Autosampler and Field Sample Carrier for Maximizing Throughput Using an Open-Air, Surface Sampling Ion Source for MS

    EPA Science Inventory

    A recently developed, commercially available, open-air, surface sampling ion source for mass spectrometers provides individual analyses in several seconds. To realize its full throughput potential, an autosampler and field sample carrier were designed and built. The autosampler ...

  12. Inactivation of the biofilm by the air plasma containing water

    NASA Astrophysics Data System (ADS)

    Suganuma, Ryota; Yasuoka, Koichi; Yasuoka Takeuchi lab Team

    2014-10-01

    Biofilms are caused by environmental degradation in food factory and medical facilities. Inactivation of biofilm has the method of making it react to chemicals including chlorine, hydrogen peroxide, and ozone. Although inactivation by chemicals has the problem that hazardous property of a residual substance and hydrogen peroxide have slow reaction velocity. We achieved advanced oxidation process (AOP) with air plasma. Hydrogen peroxide and ozone, which were used for the formation of OH radicals in our experiment, were able to be generated selectively by adjusting the amount of water supplied to the plasma. We inactivated Pseudomonas aeruginosa biofilm in five minutes with OH radicals generated by using hydrogen peroxide and ozone.

  13. Passive Samplers for Investigations of Air Quality: Method Description, Implementation, and Comparison to Alternative Sampling Methods

    EPA Science Inventory

    This Paper covers the basics of passive sampler design, compares passive samplers to conventional methods of air sampling, and discusses considerations when implementing a passive sampling program. The Paper also discusses field sampling and sample analysis considerations to ensu...

  14. Biomimetic air sampling for detection of low concentrations of molecules and bioagents : LDRD 52744 final report.

    SciTech Connect

    Hughes, Robert Clark

    2003-12-01

    Present methods of air sampling for low concentrations of chemicals like explosives and bioagents involve noisy and power hungry collectors with mechanical parts for moving large volumes of air. However there are biological systems that are capable of detecting very low concentrations of molecules with no mechanical moving parts. An example is the silkworm moth antenna which is a highly branched structure where each of 100 branches contains about 200 sensory 'hairs' which have dimensions of 2 microns wide by 100 microns long. The hairs contain about 3000 pores which is where the gas phase molecules enter the aqueous (lymph) phase for detection. Simulations of diffusion of molecules indicate that this 'forest' of hairs is 'designed' to maximize the extraction of the vapor phase molecules. Since typical molecules lose about 4 decades in diffusion constant upon entering the liquid phase, it is important to allow air diffusion to bring the molecule as close to the 'sensor' as possible. The moth acts on concentrations as low as 1000 molecules per cubic cm. (one part in 1e16). A 3-D collection system of these dimensions could be fabricated by micromachining techniques available at Sandia. This LDRD addresses the issues involved with extracting molecules from air onto micromachined structures and then delivering those molecules to microsensors for detection.

  15. A self-contained polymeric cartridge for automated biological sample preparation.

    PubMed

    Xu, Guolin; Lee, Daniel Yoke San; Xie, Hong; Chiew, Deon; Hsieh, Tseng-Ming; Ali, Emril Mohamed; Lun Looi, Xing; Li, Mo-Huang; Ying, Jackie Y

    2011-09-01

    Sample preparation is one of the most crucial processes for nucleic acids based disease diagnosis. Several steps are required for nucleic acids extraction, impurity washes, and DNA/RNA elution. Careful sample preparation is vital to the obtaining of reliable diagnosis, especially with low copies of pathogens and cells. This paper describes a low-cost, disposable lab cartridge for automatic sample preparation, which is capable of handling flexible sample volumes of 10 μl to 1 ml. This plastic cartridge contains all the necessary reagents for pathogen and cell lysis, DNA/RNA extraction, impurity washes, DNA/RNA elution and waste processing in a completely sealed cartridge. The entire sample preparation processes are automatically conducted within the cartridge on a desktop unit using a pneumatic fluid manipulation approach. Reagents transportation is achieved with a combination of push and pull forces (with compressed air and vacuum, respectively), which are connected to the pneumatic inlets at the bottom of the cartridge. These pneumatic forces are regulated by pinch valve manifold and two pneumatic syringe pumps within the desktop unit. The performance of this pneumatic reagent delivery method was examined. We have demonstrated the capability of the on-cartridge RNA extraction and cancer-specific gene amplification from 10 copies of MCF-7 breast cancer cells. The on-cartridge DNA recovery efficiency was 54-63%, which was comparable to or better than the conventional manual approach using silica spin column. The lab cartridge would be suitable for integration with lab-chip real-time polymerase chain reaction devices in providing a portable system for decentralized disease diagnosis.

  16. Carter Carburetor Weekly Air Monitoring & Sampling Report - November 2, 2015 – November 8, 2015

    EPA Pesticide Factsheets

    Carter Carburetor Daily Weather Conditions, Dairly Work Activities, Daily Air Monitoring and Samplying Results, Air Monitoring/Samplying Results –Station 2 Linc 126, Air Monitoring/Sampling Results- Sation 3 Linc 123, Air Monitoring/Samplying Results-Stati

  17. Carter Carburetor Weekly Air Monitoring & Sampling Report - November 16, 2015 – November 22, 2015

    EPA Pesticide Factsheets

    Carter Carburetor Daily Weather Conditions, Dairly Work Activities, Daily Air Monitoring and Samplying Results, Air Monitoring/Samplying Results –Station 2 Linc 126, Air Monitoring/Sampling Results- Sation 3 Linc 123, Air Monitoring/Samplying Results-Stati

  18. Carter Carburetor Weekly Air Monitoring & Sampling Report - October 12, 2015 – October 18, 2015

    EPA Pesticide Factsheets

    Carter Carburetor Daily Weather Conditions, Dairly Work Activities, Daily Air Monitoring and Samplying Results, Air Monitoring/Samplying Results –Station 2 Linc 126, Air Monitoring/Sampling Results- Sation 3 Linc 123, Air Monitoring/Samplying Results-Stati

  19. Carter Carburetor Weekly Air Monitoring & Sampling Report - March 7, 2013 - March 13, 2016

    EPA Pesticide Factsheets

    Carter Carburetor Daily Weather Conditions, Dairly Work Activities, Daily Air Monitoring and Samplying Results, Air Monitoring/Samplying Results –Station 2 Linc 126, Air Monitoring/Sampling Results- Sation 3 Linc 123, Air Monitoring/Samplying Results-Stati

  20. Carter Carburetor Weekly Air Monitoring & Sampling Report - November 30, 2015 – December 6, 2015

    EPA Pesticide Factsheets

    Carter Carburetor Daily Weather Conditions, Dairly Work Activities, Daily Air Monitoring and Samplying Results, Air Monitoring/Samplying Results –Station 2 Linc 126, Air Monitoring/Sampling Results- Sation 3 Linc 123, Air Monitoring/Samplying Results-Stati

  1. Carter Carburetor Weekly Air Monitoring & Sampling Report - November 9, 2015 – November 15, 2015

    EPA Pesticide Factsheets

    Carter Carburetor Daily Weather Conditions, Dairly Work Activities, Daily Air Monitoring and Samplying Results, Air Monitoring/Samplying Results –Station 2 Linc 126, Air Monitoring/Sampling Results- Sation 3 Linc 123, Air Monitoring/Samplying Results-Stati

  2. Carter Carburetor Weekly Air Monitoring & Sampling Report - February 1, 2016 – February 7, 2016

    EPA Pesticide Factsheets

    Carter Carburetor Daily Weather Conditions, Dairly Work Activities, Daily Air Monitoring and Samplying Results, Air Monitoring/Samplying Results –Station 2 Linc 126, Air Monitoring/Sampling Results- Sation 3 Linc 123, Air Monitoring/Samplying Results-Stati

  3. Carter Carburetor Weekly Air Monitoring & Sampling Report - October 26, 2015 – November 1, 2015

    EPA Pesticide Factsheets

    Carter Carburetor Daily Weather Conditions, Dairly Work Activities, Daily Air Monitoring and Samplying Results, Air Monitoring/Samplying Results –Station 2 Linc 126, Air Monitoring/Sampling Results- Sation 3 Linc 123, Air Monitoring/Samplying Results-Stati

  4. Carter Carburetor Weekly Air Monitoring & Sampling Report - October 5, 2015 – October 11, 2015

    EPA Pesticide Factsheets

    Carter Carburetor Daily Weather Conditions, Dairly Work Activities, Daily Air Monitoring and Samplying Results, Air Monitoring/Samplying Results –Station 2 Linc 126, Air Monitoring/Sampling Results- Sation 3 Linc 123, Air Monitoring/Samplying Results-Stati

  5. Carter Carburetor Weekly Air Monitoring & Sampling Report - September 28, 2015 – October 4, 2015

    EPA Pesticide Factsheets

    Carter Carburetor Daily Weather Conditions, Dairly Work Activities, Daily Air Monitoring and Samplying Results, Air Monitoring/Samplying Results –Station 2 Linc 126, Air Monitoring/Sampling Results- Sation 3 Linc 123, Air Monitoring/Samplying Results-Stati

  6. Carter Carburetor Weekly Air Monitoring & Sampling Report - February 15, 2016 – February 21, 2016

    EPA Pesticide Factsheets

    Carter Carburetor Daily Weather Conditions, Dairly Work Activities, Daily Air Monitoring and Samplying Results, Air Monitoring/Samplying Results –Station 2 Linc 126, Air Monitoring/Sampling Results- Sation 3 Linc 123, Air Monitoring/Samplying Results-Stati

  7. Carter Carburetor Weekly Air Monitoring & Sampling Report - October 19, 2015 – October 25, 2015

    EPA Pesticide Factsheets

    Carter Carburetor Daily Weather Conditions, Dairly Work Activities, Daily Air Monitoring and Samplying Results, Air Monitoring/Samplying Results –Station 2 Linc 126, Air Monitoring/Sampling Results- Sation 3 Linc 123, Air Monitoring/Samplying Results-Stati

  8. Carter Carburetor Weekly Air Monitoring & Sampling Report - November 23, 2015 – November 29, 2015

    EPA Pesticide Factsheets

    Carter Carburetor Daily Weather Conditions, Dairly Work Activities, Daily Air Monitoring and Samplying Results, Air Monitoring/Samplying Results –Station 2 Linc 126, Air Monitoring/Sampling Results- Sation 3 Linc 123, Air Monitoring/Samplying Results-Stati

  9. Organic toxicants in air and precipitation samples from the Lake Michigan area

    SciTech Connect

    Harlin, K.S.; Sweet, C.W.; Gatz, D.F.

    1995-12-31

    Measurements of PCBs, organochlorine insecticides, PAHs, and atrazine were made in air and precipitation samples collected at regionally-representative locations near Lake Michigan from 1992-1995. The purpose of these measurements was to provide information needed to estimate the atmospheric deposition of organic toxicants to Lake Michigan. Twenty-four hour samples of airborne particles and vapor were collected at 12-day intervals on quartz fiber filters and XAD-2 resin vapor traps using modified high volume sampleers. Twenty-eight day precipitation samples were collected using wet-only samplers with stainless steel sampling surfaces and heated enclosure containing an XAD-2 resin adsorption column. Samples were Soxhlet extracted for 24 hours with hexane:acetone (1:1), and concentrated by rotary evaporation. Interferences were removed and the samples separated into analyte groups by silica gel chromatography. Four fractions were collected for GC-ECD and GC-Ion Trap MS analyses. Ten pesticides, 101 PCB congeners, 18 PAHs, and atrazine were measured in all samples. Quality assurance was maintained by including field duplicate samples, field blanks, alboratory matrix spikes, laboratory matrix blanks, and laboratory surrogate spikes in the sampling/analytical protocols. Preliminary results from urban and remote sites show geographical variations in the concentrations of some toxicants due to contributions from local sources. For all sites the total PCB levels are higher in the vapor phase than the particulate phase and show strong seasonal variations. Seasonal variations were also observed for several pesticides.

  10. Collection and analysis of NASA clean room air samples

    NASA Technical Reports Server (NTRS)

    Sheldon, L. S.; Keever, J.

    1985-01-01

    The environment of the HALOE assembly clean room at NASA Langley Research Center is analyzed to determine the background levels of airborne organic compounds. Sampling is accomplished by pumping the clean room air through absorbing cartridges. For volatile organics, cartridges are thermally desorbed and then analyzed by gas chromatography and mass spectrometry, compounds are identified by searching the EPA/NIH data base using an interactive operator INCOS computer search algorithm. For semivolatile organics, cartridges are solvent entracted and concentrated extracts are analyzed by gas chromatography-electron capture detection, compound identification is made by matching gas chromatogram retention times with known standards. The detection limits for the semivolatile organics are; 0.89 ng cu m for dioctylphlhalate (DOP) and 1.6 ng cu m for polychlorinated biphenyls (PCB). The detection limit for volatile organics ranges from 1 to 50 parts per trillion. Only trace quantities of organics are detected, the DOP levels do not exceed 2.5 ng cu m and the PCB levels do not exceed 454 ng cu m.

  11. Dr. Grant Heikan examines lunar material in sieve from sample container

    NASA Technical Reports Server (NTRS)

    1969-01-01

    Dr. Grant Heikan, Manned Spacecraft Center and a Lunar Sample preliminary Examination Team member, examines lunar material in a sieve from the bulk sample container which was opened in the Biopreparation Laboratory of the Lunar Receiving Laboratory.

  12. Soyuz 23 Return Samples: Assessment of Air Quality Aboard the International Space Station

    NASA Technical Reports Server (NTRS)

    James, John T.

    2011-01-01

    Six mini-grab sample containers (m-GSCs) were returned aboard Soyuz 23 because of concerns that new air pollutants had been present in the air and these were getting into the water recovery system. The Total Organic Carbon Analyzer had been giving increasing readings of total organic carbon (TOC) in the potable water, and it was postulated that an increased load into the system was responsible. The TOC began to decline in late October, 2010. The toxicological assessment of 6 m-GSCs from the ISS is shown in Table 1. The recoveries of 13C-acetone, fluorobenzene, and chlorobenzene from the GSCs averaged 73, 82, and 59%, respectively. We are working to understand the sub-optimal recovery of chlorobenzene.

  13. Breakthrough of 1,3-dichloropropene and chloropicrin from 600 mg XAD-4 air sampling tubes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Accurately measuring air concentrations of agricultural fumigants is important for the regulation of air quality. Understanding the conditions under which sorbent tubes can effectively retain such fumigants during sampling is critical in mitigating chemical breakthrough from the tubes and facilitati...

  14. Cost and Performance Report of Incremental Sampling Methodology for Soil Containing Metallic Residues

    DTIC Science & Technology

    2013-09-01

    by the need for fewer ISM samples than grab samples to adequately char - acterize a DU. The cost differential between conventional grab samples and ISM...Ranney. 2003b. Evaluation of the Contamination by Explosives in Soils, Biomass and Surface Water at Cold Lake Air Weapons Range (CLAWR), Alberta, Phase...Environmental Conditions of Surface Soils and Biomass Prevailing in the Training Area at CFB Gagetown, New Brunswick. DRDC-TR-2003-152, Quebec, Canada

  15. Review of Various Air Sampling Methods for Solvent Vapors.

    DTIC Science & Technology

    Vapors of trichloroethylene, toluene, methyl ethyl ketone, and butyl cellosolve in air were collected using Scotchpac and Tedlar bags, glass ...prescription bottles , and charcoal adsorption tubes. Efficiencies of collection are reported. (Author)

  16. Review of Various Air Sampling Methods for Solvent Vapors.

    ERIC Educational Resources Information Center

    Maykoski, R. T.

    Vapors of trichloroethylene, toluene, methyl ethyl ketone, and butyl cellosolve in air were collected using Scotchpac and Tedlar bags, glass prescription bottles, and charcoal adsorption tubes. Efficiencies of collection are reported. (Author/RH)

  17. Application of a dry-gas meter for measuring air sample volumes in an ambient air monitoring network

    SciTech Connect

    Fritz, Brad G.

    2009-05-24

    Ambient air monitoring for non-research applications (e.g. compliance) occurs at locations throughout the world. Often, the air sampling systems employed for these purposes employee simple yet robust equipment capable of handling the rigors of demanding sampling schedules. At the Hanford Site (near Richland, Washington) concentrations of radionuclides in ambient air are monitored continuously at 44 locations. In 2004, mechanical dry-gas meters were incorporated into the Hanford Site ambient air sample collection system to allow the direct measurement of sample volumes. These meters replaced a portable airflow measurement system that required two manual flow measurements and a sample duration measurement to determine sample volume. A six-month evaluation of the dry-gas meters compared sample volumes calculated using the original flow rate method to the direct sample volume measurement (new method). The results of the evaluation indicate that use of the dry-gas meters result in accurate sample volume measurements and provide greater confidence in the measured sample volumes. In several years of in-network use, the meters have proven to be reliable and have resulted in an improved sampling system.

  18. Development of a sampling and analysis method for 4-vinyl-1-cyclohexene in air.

    PubMed

    Kongtip, Pornpimol; Tangprakorn, Bantoon; Yoosook, Witaya; Chantanakul, Suttinun

    2008-01-01

    The purpose of this research was to develop an applicable sampling and analytical method to determine airborne 4-vinyl-1-cyclohexene concentrations which are usually found in the atmosphere of polybutadiene factories. A solid sorbent tube, containing two sections (100 mg in the front and 50 mg in the back) of activated coconut-shell charcoal was chosen for sampling 4-vinyl-1-cyclohexene vapor. The 4-vinyl-1-cyclohexene in the charcoal samples was desorbed with carbon disulfide and analyzed by gas chromatography equipped with a flame ionization detector. The suitable air flow rate, adsorption capacity, sample storage stability, desorption efficiency and reliability of the method for sampling and analysis of 4-vinyl-1-cyclohexene were evaluated. The method was applied to sampling and analysis of 4-vinyl-1-cyclohexene in the rubber industry. The results indicated a suitable air flow rate of 0.3 to 1.5 l/min. The adsorption capacity of 4-vinyl-1-cyclohexene on 100 mg of charcoal was 0.2134 mg. The 4-vinyl-1-cyclohexene adsorbed on the charcoal was stable for 7 d at room temperature or 21 d in a refrigerated condition. The average percent desorption efficiency of 4-vinyl-1-cyclohexene ranged from 90.45% to 97.04% with the loaded amount ranging from 0.412 to 8.250 microg using 1 ml carbon disulfide. The limit of detection of 4-vinyl-1-cyclohexene was 0.044 ng. The average percent recoveries (n=6) of 4-vinyl-1-cyclohexene adsorbed on charcoal ranging from 0.46 to 8.87 microg were 96.78-102.87% with relative standard deviations (RSDs) of 0.34-1.92%, respectively. The concentrations of 4-vinyl-1-cyclohexene ranged from 0.011 to 0.105 mg/m(3) in the working environment of a polybutadiene factory.

  19. Characterization Data Package for Containerized Sludge Samples Collected from Engineered Container SCS-CON-210

    SciTech Connect

    Fountain, Matthew S.; Fiskum, Sandra K.; Baldwin, David L.; Daniel, Richard C.; Bos, Stanley J.; Burns, Carolyn A.; Carlson, Clark D.; Coffey, Deborah S.; Delegard, Calvin H.; Edwards, Matthew K.; Greenwood, Lawrence R.; Neiner, Doinita; Oliver, Brian M.; Pool, Karl N.; Schmidt, Andrew J.; Shimskey, Rick W.; Sinkov, Sergey I.; Snow, Lanee A.; Soderquist, Chuck Z.; Thompson, Christopher J.; Trang-Le, Truc LT; Urie, Michael W.

    2013-09-10

    This data package contains the K Basin sludge characterization results obtained by Pacific Northwest National Laboratory during processing and analysis of four sludge core samples collected from Engineered Container SCS-CON-210 in 2010 as requested by CH2M Hill Plateau Remediation Company. Sample processing requirements, analytes of interest, detection limits, and quality control sample requirements are defined in the KBC-33786, Rev. 2. The core processing scope included reconstitution of a sludge core sample distributed among four to six 4-L polypropylene bottles into a single container. The reconstituted core sample was then mixed and subsampled to support a variety of characterization activities. Additional core sludge subsamples were combined to prepare a container composite. The container composite was fractionated by wet sieving through a 2,000 micron mesh and a 500-micron mesh sieve. Each sieve fraction was sampled to support a suite of analyses. The core composite analysis scope included density determination, radioisotope analysis, and metals analysis, including the Waste Isolation Pilot Plant Hazardous Waste Facility Permit metals (with the exception of mercury). The container composite analysis included most of the core composite analysis scope plus particle size distribution, particle density, rheology, and crystalline phase identification. A summary of the received samples, core sample reconstitution and subsampling activities, container composite preparation and subsampling activities, physical properties, and analytical results are presented. Supporting data and documentation are provided in the appendices. There were no cases of sample or data loss and all of the available samples and data are reported as required by the Quality Assurance Project Plan/Sampling and Analysis Plan.

  20. Experimental and numerical investigations on reliability of air barrier on oil containment in flowing water.

    PubMed

    Lu, Jinshu; Xu, Zhenfeng; Xu, Song; Xie, Sensen; Wu, Haoxiao; Yang, Zhenbo; Liu, Xueqiang

    2015-06-15

    Air barriers have been recently developed and employed as a new type of oil containment boom. This paper presents systematic investigations on the reliability of air barriers on oil containments with the involvement of flowing water, which represents the commonly-seen shearing current in reality, by using both laboratory experiments and numerical simulations. Both the numerical and experimental investigations are carried out in a model scale. In the investigations, a submerged pipe with apertures is installed near the bottom of a tank to generate the air bubbles forming the air curtain; and, the shearing water flow is introduced by a narrow inlet near the mean free surface. The effects of the aperture configurations (including the size and the spacing of the aperture) and the location of the pipe on the effectiveness of the air barrier on preventing oil spreading are discussed in details with consideration of different air discharges and velocities of the flowing water. The research outcome provides a foundation for evaluating and/or improve the reliability of a air barrier on preventing spilled oil from further spreading.

  1. Detection of pollen grains in multifocal optical microscopy images of air samples.

    PubMed

    Landsmeer, Sander H; Hendriks, Emile A; de Weger, Letty A; Reiber, Johan H C; Stoel, Berend C

    2009-06-01

    Pollen is a major cause of allergy and monitoring pollen in the air is relevant for diagnostic purposes, development of pollen forecasts, and for biomedical and biological researches. Since counting airborne pollen is a time-consuming task and requires specialized personnel, an automated pollen counting system is desirable. In this article, we present a method for detecting pollen in multifocal optical microscopy images of air samples collected by a Burkard pollen sampler, as a first step in an automated pollen counting procedure. Both color and shape information was used to discriminate pollen grains from other airborne material in the images, such as fungal spores and dirt. A training set of 44 images from successive focal planes (stacks) was used to train the system in recognizing pollen color and for optimization. The performance of the system has been evaluated using a separate set of 17 image stacks containing 65 pollen grains, of which 86% was detected. The obtained precision of 61% can still be increased in the next step of classifying the different pollen in such a counting system. These results show that the detection of pollen is feasible in images from a pollen sampler collecting ambient air. This first step in automated pollen detection may form a reliable basis for an automated pollen counting system.

  2. Second Line of Defense, Port of Buenos Aires and Exolgan Container Terminal Operational Testing and Evaluation Plan, Buenos Aires, Argentina

    SciTech Connect

    Roberts, Bryan W.

    2012-08-23

    The Office of the Second Line of Defense (SLD) Megaports project team for Argentina will conduct operational testing and evaluation (OT&E) at Exolgan Container Terminal at the Port of Dock Sud from July 16-20, 2012; and at the Port of Buenos Aires from September 3-7, 2012. SLD is installing radiation detection equipment to screen export, import, and transshipment containers at these locations. The purpose of OT&E is to validate and baseline an operable system that meets the SLD mission and to ensure the system continues to perform as expected in an operational environment with Argentina Customs effectively adjudicating alarms.

  3. Low-cost monitoring of Campylobacter in poultry houses by air sampling and quantitative PCR.

    PubMed

    Søndergaard, M S R; Josefsen, M H; Löfström, C; Christensen, L S; Wieczorek, K; Osek, J; Hoorfar, J

    2014-02-01

    The present study describes the evaluation of a method for the quantification of Campylobacter by air sampling in poultry houses. Sampling was carried out in conventional chicken houses in Poland, in addition to a preliminary sampling in Denmark. Each measurement consisted of three air samples, two standard boot swab fecal samples, and one airborne particle count. Sampling was conducted over an 8-week period in three flocks, assessing the presence and levels of Campylobacter in boot swabs and air samples using quantitative real-time PCR. The detection limit for air sampling was approximately 100 Campylobacter cell equivalents (CCE)/m3. Airborne particle counts were used to analyze the size distribution of airborne particles (0.3 to 10 μm) in the chicken houses in relation to the level of airborne Campylobacter. No correlation was found. Using air sampling, Campylobacter was detected in the flocks right away, while boot swab samples were positive after 2 weeks. All samples collected were positive for Campylobacter from week 2 through the rest of the rearing period for both sampling techniques, although levels 1- to 2-log CCE higher were found with air sampling. At week 8, the levels were approximately 10(4) and 10(5) CCE per sample for boot swabs and air, respectively. In conclusion, using air samples combined with quantitative real-time PCR, Campylobacter contamination could be detected earlier than by boot swabs and was found to be a more convenient technique for monitoring and/or to obtain enumeration data useful for quantitative risk assessment of Campylobacter.

  4. Cast Stone Oxidation Front Evaluation: Preliminary Results For Samples Exposed To Moist Air

    SciTech Connect

    Langton, C. A.; Almond, P. M.

    2013-11-26

    The rate of oxidation is important to the long-term performance of reducing salt waste forms because the solubility of some contaminants, e.g., technetium, is a function of oxidation state. TcO{sub 4}{sup -} in the salt solution is reduced to Tc(IV) and has been shown to react with ingredients in the waste form to precipitate low solubility sulfide and/or oxide phases. Upon exposure to oxygen, the compounds containing Tc(IV) oxidize to the pertechnetate ion, Tc(VII)O{sub 4}{sup -}, which is very soluble. Consequently the rate of technetium oxidation front advancement into a monolith and the technetium leaching profile as a function of depth from an exposed surface are important to waste form performance and ground water concentration predictions. An approach for measuring contaminant oxidation rate (effective contaminant specific oxidation rate) based on leaching of select contaminants of concern is described in this report. In addition, the relationship between reduction capacity and contaminant oxidation is addressed. Chromate (Cr(VI) was used as a non-radioactive surrogate for pertechnetate, Tc(VII), in Cast Stone samples prepared with 5 M Simulant. Cast Stone spiked with pertechnetate was also prepared and tested. Depth discrete subsamples spiked with Cr were cut from Cast Stone exposed to Savannah River Site (SRS) outdoor ambient temperature fluctuations and moist air. Depth discrete subsamples spiked with Tc-99 were cut from Cast Stone exposed to laboratory ambient temperature fluctuations and moist air. Similar conditions are expected to be encountered in the Cast Stone curing container. The leachability of Cr and Tc-99 and the reduction capacities, measured by the Angus-Glasser method, were determined for each subsample as a function of depth from the exposed surface. The results obtained to date were focused on continued method development and are preliminary and apply to the sample composition and curing / exposure conditions described in this report. The

  5. PULMONARY TOXICOLOGY OF SYNTHETIC AIR POLLUTION PARTICLES CONTAINING METAL SULFATES COMPARED TO CARBON BLACK AND DIESEL

    EPA Science Inventory

    PULMONARY TOXICITY OF SYNTHETIC AIR POLLUTION PARTICLES CONTAINING METAL SULFATES COMPARED TO CARBON BLACK AND DIESEL.

    M Daniels, A Ranade* & MJ Selgrade & MI Gilmour.
    Experimental Toxicology Division, ORD/NHEERL, U.S. EPA, RTP, NC. * Particle Technology, College Par...

  6. BIBLE A whole-air sampling as a window on Asian biogeochemistry

    NASA Astrophysics Data System (ADS)

    Elliott, Scott; Blake, Donald R.; Blake, Nicola J.; Dubey, Manvendra K.; Rowland, F. Sherwood; Sive, Barkley C.; Smith, Felisa A.

    2003-02-01

    Asian trace gas and aerosol emissions into carbon, nitrogen, and other elemental cycles will figure prominently in near term Earth system evolution. Atmospheric hydrocarbon measurements resolve numerous chemical species and can be used to investigate sourcing for key geocarriers. A recent aircraft study of biomass burning and lightning (BIBLE A) explored the East Asian atmosphere and was unique in centering on the Indonesian archipelago. Samples of volatile organics taken over/between the islands of Japan, Saipan, Java, and Borneo are here examined as a guide to whole-air-based studies of future Asian biogeochemistry. The midlatitude onshore/offshore pulse and tropical convection strongly influence concentration distributions. As species of increasing molecular weight are considered, rural, combustion, and industrial source regimes emerge. Methane-rich inputs such as waste treatment and rice cultivation are evidenced in the geostrophic outflow. The Indonesian atmosphere is rich in biomass burning markers and also those of vehicular activity. Complexity of air chemistry in the archipelago is a direct reflection of diverse topography, land use, and local economies in a rapidly developing nation. Conspicuous in its absence is the fingerprint for liquefied petroleum gas leakage, but it can be expected to appear as demand for clean fossil fuels rises along with per capita incomes. Combustion tracers indicate high nitrogen mobilization rates, linking regional terrestrial geocycles with open marine ecosystems. Sea to air fluxes are superimposed on continental and marine backgrounds for the methyl halides. However, ocean hot spots are not coordinated and suggest an intricate subsurface kinetics. Levels of long-lived anthropogenic halocarbons attest to the success of international environmental treaties while reactive chlorine containing species track industrial air masses. The dozens of hydrocarbons resolvable by gas chromatographic methods will enable monitoring of

  7. 9 CFR 310.21 - Carcasses suspected of containing sulfa and antibiotic residues; sampling frequency; disposition...

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 9 Animals and Animal Products 2 2013-01-01 2013-01-01 false Carcasses suspected of containing sulfa and antibiotic residues; sampling frequency; disposition of affected carcasses and parts. 310.21... antibiotic residues; sampling frequency; disposition of affected carcasses and parts. (a) Calf carcasses...

  8. 9 CFR 310.21 - Carcasses suspected of containing sulfa and antibiotic residues; sampling frequency; disposition...

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Carcasses suspected of containing sulfa and antibiotic residues; sampling frequency; disposition of affected carcasses and parts. 310.21... antibiotic residues; sampling frequency; disposition of affected carcasses and parts. (a) Calf carcasses...

  9. 9 CFR 310.21 - Carcasses suspected of containing sulfa and antibiotic residues; sampling frequency; disposition...

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 2 2012-01-01 2012-01-01 false Carcasses suspected of containing sulfa and antibiotic residues; sampling frequency; disposition of affected carcasses and parts. 310.21... antibiotic residues; sampling frequency; disposition of affected carcasses and parts. (a) Calf carcasses...

  10. 9 CFR 310.21 - Carcasses suspected of containing sulfa and antibiotic residues; sampling frequency; disposition...

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 9 Animals and Animal Products 2 2011-01-01 2011-01-01 false Carcasses suspected of containing sulfa and antibiotic residues; sampling frequency; disposition of affected carcasses and parts. 310.21... antibiotic residues; sampling frequency; disposition of affected carcasses and parts. (a) Calf carcasses...

  11. 9 CFR 310.21 - Carcasses suspected of containing sulfa and antibiotic residues; sampling frequency; disposition...

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 2 2014-01-01 2014-01-01 false Carcasses suspected of containing sulfa and antibiotic residues; sampling frequency; disposition of affected carcasses and parts. 310.21... antibiotic residues; sampling frequency; disposition of affected carcasses and parts. (a) Calf carcasses...

  12. Review of the Physical Science Facility Stack Air Sampling Probe Locations

    SciTech Connect

    Glissmeyer, John A.

    2007-09-30

    This letter report reviews compliance of the current design of the Physical Science Facility (PSF) stack air sampling locations with the ANSI/HPS N13.1-1999 standard. The review was based on performance criteria used for locating air sampling probes, the design documents provided and available information on systems previously tested for compliance with the criteria. Recommendations are presented for ways to bring the design into compliance with the requirements for the sampling probe placement.

  13. Comparison of stationary and personal air sampling with an air dispersion model for children's ambient exposure to manganese.

    PubMed

    Fulk, Florence; Haynes, Erin N; Hilbert, Timothy J; Brown, David; Petersen, Dan; Reponen, Tiina

    2016-09-01

    Manganese (Mn) is ubiquitous in the environment and essential for normal growth and development, yet excessive exposure can lead to impairments in neurological function. This study modeled ambient Mn concentrations as an alternative to stationary and personal air sampling to assess exposure for children enrolled in the Communities Actively Researching Exposure Study in Marietta, OH. Ambient air Mn concentration values were modeled using US Environmental Protection Agency's Air Dispersion Model AERMOD based on emissions from the ferromanganese refinery located in Marietta. Modeled Mn concentrations were compared with Mn concentrations from a nearby stationary air monitor. The Index of Agreement for modeled versus monitored data was 0.34 (48 h levels) and 0.79 (monthly levels). Fractional bias was 0.026 for 48 h levels and -0.019 for monthly levels. The ratio of modeled ambient air Mn to measured ambient air Mn at the annual time scale was 0.94. Modeled values were also time matched to personal air samples for 19 children. The modeled values explained a greater degree of variability in personal exposures compared with time-weighted distance from the emission source. Based on these results modeled Mn concentrations provided a suitable approach for assessing airborne Mn exposure in this cohort.

  14. Summary of gamma spectrometry on local air samples from 1985--1995

    SciTech Connect

    Winn, W.G.

    1997-04-02

    This report summarizes the 1985--1995 results of low-level HPGe gamma spectrometry analysis of high-volume air samples collected at the Aiken Airport, which is about 25 miles north of SRS. The author began analyzing these samples with new calibrations using the newly developed GRABGAM code in 1985. The air sample collections were terminated in 1995, as the facilities at the Aiken Airport were no longer available. Air sample measurements prior to 1985 were conducted with a different analysis system (and by others prior to 1984), and the data were not readily available. The report serves to closeout this phase of local NTS air sample studies, while documenting the capabilities and accomplishments. Hopefully, the information will guide other applications for this technology, both locally and elsewhere.

  15. Minimum detectable activity concentration in direct alpha spectrometry from outdoor air samples: continuous monitoring versus separate sampling and counting.

    PubMed

    Pöllänen, R; Siiskonen, T

    2006-02-01

    Rapid method for identifying the presence of alpha particle emitting radionuclides in outdoor air is of paramount importance should a nuclear or radiological incident occur. Minimum detectable activity concentrations of U, U, Pu, and Pu in outdoor air are calculated for two direct alpha spectrometry methods: continuous air monitoring is compared with separate sampling and subsequent alpha particle counting in a vacuum chamber. The radon progeny activity concentration typical for outdoor air and the effects for the alpha particle spectra caused by the properties of the filter and the aerosol particles are taken into account using measurements and Monte Carlo simulations. Continuous air monitoring is a faster method for identifying the presence of (trans)uranium elements when their activity concentration is considerably higher than the typical detection limit. Separate sampling and counting in a vacuum chamber is a more sensitive method when concentrations are close to the detection limit and when the duration of the sampling-counting cycle is greater than approximately 2 h. The method may serve as a tool for rapid field measurements.

  16. A method to optimize sampling locations for measuring indoor air distributions

    NASA Astrophysics Data System (ADS)

    Huang, Yan; Shen, Xiong; Li, Jianmin; Li, Bingye; Duan, Ran; Lin, Chao-Hsin; Liu, Junjie; Chen, Qingyan

    2015-02-01

    Indoor air distributions, such as the distributions of air temperature, air velocity, and contaminant concentrations, are very important to occupants' health and comfort in enclosed spaces. When point data is collected for interpolation to form field distributions, the sampling locations (the locations of the point sensors) have a significant effect on time invested, labor costs and measuring accuracy on field interpolation. This investigation compared two different sampling methods: the grid method and the gradient-based method, for determining sampling locations. The two methods were applied to obtain point air parameter data in an office room and in a section of an economy-class aircraft cabin. The point data obtained was then interpolated to form field distributions by the ordinary Kriging method. Our error analysis shows that the gradient-based sampling method has 32.6% smaller error of interpolation than the grid sampling method. We acquired the function between the interpolation errors and the sampling size (the number of sampling points). According to the function, the sampling size has an optimal value and the maximum sampling size can be determined by the sensor and system errors. This study recommends the gradient-based sampling method for measuring indoor air distributions.

  17. High Volume Air Sampling for Viral Aerosols: A Comparative Approach

    DTIC Science & Technology

    2010-03-01

    low, with the cotton swabbing only recovering 27.7 percent of the BA on the surface (Rose, Jensen, Peterson, Banerjee, & Arduino , 2004). A follow-on...BA were present on the surface (Hodges, Rose, Peterson, Noble-Wang, & Arduino , 2006). These lower sensitivities at low concentrations could be a...monitored during each sample collection period. Ambient pressure data was obtained hourly for Edmonton, AB from the Canadian Weather Service

  18. A STRINGENT COMPARISON OF SAMPLING AND ANALYSIS METHODS FOR VOCS IN AMBIENT AIR

    EPA Science Inventory

    A carefully designed study was conducted during the summer of 1998 to simultaneously collect samples of ambient air by canisters and compare the analysis results to direct sorbent preconcentration results taken at the time of sample collection. A total of 32 1-h sample sets we...

  19. Assessment of Residual Stresses in 3013 Inner and Outer Containers and Teardrop Samples

    SciTech Connect

    Stroud, Mary Ann; Prime, Michael Bruce; Veirs, Douglas Kirk; Berg, John M.; Clausen, Bjorn; Worl, Laura Ann; DeWald, Adrian T.

    2015-12-08

    This report is an assessment performed by LANL that examines packaging for plutonium-bearing materials and the resilience of its design. This report discusses residual stresses in the 3013 outer, the SRS/Hanford and RFETS/LLNL inner containers, and teardrop samples used in studies to assess the potential for SCC in 3013 containers. Residual tensile stresses in the heat affected zones of the closure welds are of particular concern.

  20. Salmonella recovery following air chilling for matched neck-skin and whole carcass sampling methodologies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The prevalence and serogroups of Salmonella recovered following air chilling were determined for both enriched neck skin and matching enriched whole carcass samples. Commercially processed and eviscerated carcasses were air chilled to 4C before removing the neck skin (8.3 g) and stomaching in 83 mL...

  1. Monte Carlo simulation of air sampling methods for the measurement of radon decay products.

    PubMed

    Sima, Octavian; Luca, Aurelian; Sahagia, Maria

    2017-02-21

    A stochastic model of the processes involved in the measurement of the activity of the (222)Rn decay products was developed. The distributions of the relevant factors, including air sampling and radionuclide collection, are propagated using Monte Carlo simulation to the final distribution of the measurement results. The uncertainties of the (222)Rn decay products concentrations in the air are realistically evaluated.

  2. Sampling and Analyzing Air Pollution: An Apparatus Suitable for Use in Schools.

    ERIC Educational Resources Information Center

    Rockwell, Dean M.; Hansen, Tony

    1994-01-01

    Describes two variations of an air sampler and analyzer that are inexpensive to construct, easy to operate, and designed to be used in an educational program. Variations use vacuum cleaners and aquarium pumps, and white facial tissues serve as filters. Samples of air pollution obtained by this method may be used from early grade school to advanced…

  3. Fungal spore concentrations in two haematopoietic stem cell transplantation (HSCT) units containing distinct air control systems.

    PubMed

    Brun, C P; Miron, D; Silla, L M R; Pasqualotto, A C

    2013-04-01

    Invasive fungal diseases have emerged as important causes of morbidity and mortality in haematological patients. In this study air samples were collected in two haematopoietic stem cell transplantation (HSCT) units, in which distinct air-control systems were in place. In hospital 1 no high-efficiency particulate air (HEPA) filter was available whereas in hospital 2 HSCT rooms were equipped with HEPA filters, with positive air pressure in relation to the corridor. A total of 117 samples from rooms, toilets and corridors were obtained during December 2009 to January 2011, using a six-stage Andersen sampler. In both hospitals, the concentration of potentially pathogenic fungi in the air was reduced in patients' rooms compared to corridors (P < 0·0001). Despite the presence of a HEPA filter in hospital 2, rooms in both hospitals showed similar concentrations of potentially pathogenic fungi (P = 0·714). These findings may be explained by the implementation of additional protective measures in hospital 1, emphasizing the importance of such measures in protected environments.

  4. NEW APPLICATION OF PASSIVE SAMPLING DEVICES FOR ASSESSMENT OF RESPIRATORY EXPOSURE TO PESTICIDES IN INDOOR AIR

    EPA Science Inventory

    The United States Environmental Protection Agency (EPA) has long maintained an interest in potential applications of passive sampling devices (PSDs) for estimating the concentrations of various pollutants in air. Typically PSDs were designed for the workplace monitoring of vola...

  5. TECHNOLOGY EVALUATION REPORT CEREX ENVIRONMENTAL SERVICES UV HOUND POINT SAMPLE AIR MONITOR

    EPA Science Inventory

    The USEPA's National Homeland Security Research Center (NHSRC) Technology Testing and Evaluation Program (TTEP) is carrying out performance tests on homeland security technologies. Under TTEP, Battelle evaluated the performance of the Cerex UV Hound point sample air monitor in de...

  6. A method for reducing and evaluating blanks in Tenax air sampling cartridges

    NASA Astrophysics Data System (ADS)

    Hubbard, Sarah A.; Russwurm, George M.; Walburn, Stephen G.

    Clean sorbent cartridges are essential in ambient air sampling to avoid false analytical results. This paper describes a procedure for the construction and cleaning of a Tenax cartridge. A definition is formulated to describe a clean cartridge quantitatively.

  7. Mixed species radioiodine air sampling readout and dose assessment system

    DOEpatents

    Distenfeld, Carl H.; Klemish, Jr., Joseph R.

    1978-01-01

    This invention provides a simple, reliable, inexpensive and portable means and method for determining the thyroid dose rate of mixed airborne species of solid and gaseous radioiodine without requiring highly skilled personnel, such as health physicists or electronics technicians. To this end, this invention provides a means and method for sampling a gas from a source of a mixed species of solid and gaseous radioiodine for collection of the mixed species and readout and assessment of the emissions therefrom by cylindrically, concentrically and annularly molding the respective species around a cylindrical passage for receiving a conventional probe-type Geiger-Mueller radiation detector.

  8. Automated syringe sampler. [remote sampling of air and water

    NASA Technical Reports Server (NTRS)

    Purgold, G. C. (Inventor)

    1981-01-01

    A number of sampling services are disposed in a rack which slides into a housing. In response to a signal from an antenna, the circutry elements are activated which provide power individually, collectively, or selectively to a servomechanism thereby moving an actuator arm and the attached jawed bracket supporting an evaculated tube towards a stationary needle. One open end of the needle extends through the side wall of a conduit to the interior and the other open end is maintained within the protective sleeve, supported by a bifurcated bracket. A septum in punctured by the end of the needle within the sleeve and a sample of the fluid medium in the conduit flows through the needle and is transferred to a tube. The signal to the servo is then reversed and the actuator arm moves the tube back to its original position permitting the septum to expand and seal the hole made by the needle. The jawed bracket is attached by pivot to the actuator to facilitate tube replacement.

  9. The NYC native air sampling pilot project: using HVAC filter data for urban biological incident characterization.

    PubMed

    Ackelsberg, Joel; Leykam, Frederic M; Hazi, Yair; Madsen, Larry C; West, Todd H; Faltesek, Anthony; Henderson, Gavin D; Henderson, Christopher L; Leighton, Terrance

    2011-09-01

    Native air sampling (NAS) is distinguished from dedicated air sampling (DAS) devices (eg, BioWatch) that are deployed to detect aerosol disseminations of biological threat agents. NAS uses filter samples from heating, ventilation, and air conditioning (HVAC) systems in commercial properties for environmental sampling after DAS detection of biological threat agent incidents. It represents an untapped, scientifically sound, efficient, widely distributed, and comparably inexpensive resource for postevent environmental sampling. Calculations predict that postevent NAS would be more efficient than environmental surface sampling by orders of magnitude. HVAC filter samples could be collected from pre-identified surrounding NAS facilities to corroborate the DAS alarm and delineate the path taken by the bioaerosol plume. The New York City (NYC) Native Air Sampling Pilot Project explored whether native air sampling would be acceptable to private sector stakeholders and could be implemented successfully in NYC. Building trade associations facilitated outreach to and discussions with property owners and managers, who expedited contact with building managers of candidate NAS properties that they managed or owned. Nominal NAS building requirements were determined; procedures to identify and evaluate candidate NAS facilities were developed; data collection tools and other resources were designed and used to expedite candidate NAS building selection and evaluation in Manhattan; and exemplar environmental sampling playbooks for emergency responders were completed. In this sample, modern buildings with single or few corporate tenants were the best NAS candidate facilities. The Pilot Project successfully demonstrated that in one urban setting a native air sampling strategy could be implemented with effective public-private collaboration.

  10. Comparison of stationary and personal air sampling with an air dispersion model for children’s ambient exposure to manganese

    EPA Science Inventory

    Manganese (Mn) is ubiquitous in the environment and essential for normal growth and development, yet excessive exposure can lead to impairments in neurological function. This study modeled ambient Mn concentrations as an alternative to stationary and personal air sampling to asse...

  11. Evaluation of a method to detect Mycobacterium bovis in air samples from infected Eurasian badgers (Meles meles) and their setts.

    PubMed

    Jones, R M; Ashford, R; Cork, J; Palmer, S; Wood, E; Spyvee, P; Parks, S; Bennett, A; Brewer, J; Delahay, R; Chambers, M; Sawyer, J

    2013-05-01

    Environmental air sampling was evaluated as a method to detect the presence of M. bovis in the vicinity of infected badgers and their setts. Airborne particles were collected on gelatine filters using a commercially available air sampling instrument and tested for the presence of M. bovis using bacteriological culture and real-time PCR. The sensitivity of bacteriological culture was broadly similar to that of real-time PCR when testing samples artificially spiked with M. bovis. Sampling was undertaken from directly under the muzzles of badgers which had been experimentally infected with M. bovis (37 samples), within enclosures housing the experimentally infected animals (50 samples), and in the vicinity of setts with resident infected wild badgers (52 samples). The methods employed did not detect M. bovis from either infected badgers or artificial or natural setts known to contain infected animals. However, samples taken at four of the six natural setts were positive for Mycobacterium gordonae.

  12. Bifurcations of a creeping air-water flow in a conical container

    NASA Astrophysics Data System (ADS)

    Balci, Adnan; Brøns, Morten; Herrada, Miguel A.; Shtern, Vladimir N.

    2016-10-01

    This numerical study describes the eddy emergence and transformations in a slow steady axisymmetric air-water flow, driven by a rotating top disk in a vertical conical container. As water height Hw and cone half-angle β vary, numerous flow metamorphoses occur. They are investigated for β =30°, 45°, and 60°. For small Hw, the air flow is multi-cellular with clockwise meridional circulation near the disk. The air flow becomes one cellular as Hw exceeds a threshold depending on β . For all β , the water flow has an unbounded number of eddies whose size and strength diminish as the cone apex is approached. As the water level becomes close to the disk, the outmost water eddy with clockwise meridional circulation expands, reaches the interface, and induces a thin layer with anticlockwise circulation in the air. Then this layer expands and occupies the entire air domain. The physical reasons for the flow transformations are provided. The results are of fundamental interest and can be relevant for aerial bioreactors.

  13. Effect of air pressure differential on vapor flow through sample building walls

    SciTech Connect

    Stewart, W.E. Jr.

    1998-12-31

    Laboratory scale experiments were performed on two small sample composite walls of typical building construction to determine the approximate opposing air pressure difference required to stop or significantly reduce the transmission of water vapor due to a water vapor pressure difference. The experiments used wall section samples between two controlled atmosphere chambers. One chamber was held at a temperature and humidity condition approximating that of a typical summer day, while the other chamber was controlled at a condition typical of indoor conditioned space. Vapor transmission data through the wall samples were obtained over a range of vapor pressure differentials and opposing air pressure differentials. The results show that increasing opposing air pressure differences decrease water vapor transmission, as expected, and relatively small opposing air pressure differentials are required for wall materials of small vapor permeability and large air permeability. The opposing air pressure that stopped or significantly reduced the flow of water vapor through the wall sample was determined experimentally and also compared to air pressures as predicted by an analytical model.

  14. Aerosol sampling system

    DOEpatents

    Masquelier, Donald A.

    2004-02-10

    A system for sampling air and collecting particulate of a predetermined particle size range. A low pass section has an opening of a preselected size for gathering the air but excluding particles larger than the sample particles. An impactor section is connected to the low pass section and separates the air flow into a bypass air flow that does not contain the sample particles and a product air flow that does contain the sample particles. A wetted-wall cyclone collector, connected to the impactor section, receives the product air flow and traps the sample particles in a liquid.

  15. ECTFE (HALAR) as a New Material for Primary Sample Containment of Astromaterials

    NASA Technical Reports Server (NTRS)

    Calaway, Michael J.; McConnell, J.T.

    2014-01-01

    Fluoropolymers, such as Teflon® (PTFE, PFA, FEP) and Viton® (FKM), have been used for over 40 years in curating astromaterials at NASA JSC. In general, fluoropolymers have low outgassing and particle shedding properties that reduce cross-contamination to curated samples. Ethylene - Chlorotrifluoroethylene (ECTFE), commonly called Halar® (trademark of Solvay Solexis), is a partially fluorinated semi-crystalline copolymer in the same class of fluoropolymers with superior abrasion resistance and extremely low permeability to liquids, gases, and vapors than any other fluoropolymer (fig. 1). ECTFE coatings are becoming more popular in the nuclear, semiconductor, and biomedical industry for lining isolation containment gloveboxes and critical piping as well as other clean room applications. A study was conducted at NASA JSC to evaluate the potential use of Halar on future sample return missions as a material for primary sample containment.

  16. Fabrication and characterization of buckypapers for use in air sampling

    NASA Astrophysics Data System (ADS)

    Oh, Jonghwa

    Occupational exposure to volatile organic compounds (VOCs) is a concern from a public health perspective. In many industrial activities, workers' exposure to VOCs can be sufficiently high to induce adverse health effects, so their monitoring is necessary. In exposure assessment, post sampling extraction and quantification are the typical analytical procedures. Recently, our group developed the photothermal desorption (PTD) technique in which a pulse of light thermally desorbs an analyte directly from a sorbent. Advantages of this technique are; it is solvent free, repeated analysis is possible, sorbents are reusable, and no high cost of equipment is required. PTD overcomes almost all drawbacks of current extraction methods. This study was aimed to develop and test a new sorbent which will efficiently work with PTD. Single-walled carbon nanotubes (SWNTs) were examined as potential sorbents because of their high surface area, great thermal conductivity, and efficient light absorption. SWNTs were fabricated into a self-supporting form (i.e., buckypaper (BP)) which will preserve its physical integrity under normal working conditions. Largely two types of SWNTs were used, arc discharge (AD) and high-pressure carbon monoxide (HiPco), and different fabrication methods were examined. Upon fabrication, their adsorption properties were characterized in terms of Brunauer, Emmett, and Teller (BET) surface area, pore size, and toluene adsorption capacity. HiPco BP and methanol-cleaned AD BP (suspended/rinsed with methanol) were the top two materials, showing the highest surface area (649 and 387 m²/g, respectively) and adsorption capacity (106 and 46 mg/g, respectively) with relatively small mean pore diameter (7.7 and 8.8 nm, respectively). To further improve the adsorption properties, specific heat treatment conditions for each type of BPs were employed. After initial treatments only HiPco BP and acetone-cleaned AD BP (suspended/rinsed with acetone) were selected for further

  17. The variation of the relative humidity of air released from canisters after ambient sampling

    SciTech Connect

    McClenny, W.A.; Schmidt, S.M.; Kronmiller, K.G.

    1997-12-31

    Dalton`s Law of partial pressures and the hypothesis that water vapor equilibrium above a canister surface is identical to that established above liquid water are used to predict the variation of the percent relative humidity (%RH) of air released from canisters used in ambient air sampling, typically 6L canisters pressurized with 18L of air. During sampling, some water vapor is adsorbed on the canister wall. When (and if) the water vapor partial pressure exceeds its saturation vapor pressure, water vapor condensation begins and the condensation rate equals the sampling rate of water vapor into the canister. Under constant temperature conditions, the air subsequently released from the canister is less humid than the original sample, following the relationship, %RH = 100% (6L/V{sub s}) for V{sub s} > V{sub r} where V{sub s} is the residual air volume and V{sub r} is the residual air volume at which water is completely removed (except for adsorbed water vapor) from the canister wall. For V{sub s} < V{sub r} the %RH is constant and equal to its value at V{sub r}, V{sub r} is shown to depend on the %RH of the ambient air sample. Experimental values to agree reasonably well with predictions; however, experimental values were systematically lower than predicted especially when ambient air with mid-range %RH was sampled. This difference is related to the mass of water vapor remaining adsorbed on the canister surface as water evaporates. This paper has been reviewed in accordance with the U.S. Environmental Protection Agency`s peer and administrative review policies and approved for presentation and publication. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.

  18. Stratospheric Air Sub-sampler (SAS) and its application to analysis of Δ17O(CO2) from small air samples collected with an AirCore

    NASA Astrophysics Data System (ADS)

    Janina Mrozek, Dorota; van der Veen, Carina; Hofmann, Magdalena E. G.; Chen, Huilin; Kivi, Rigel; Heikkinen, Pauli; Röckmann, Thomas

    2016-11-01

    We present the set-up and a scientific application of the Stratospheric Air Sub-sampler (SAS), a device to collect and to store the vertical profile of air collected with an AirCore (Karion et al., 2010) in numerous sub-samples for later analysis in the laboratory. The SAS described here is a 20 m long 1/4 inch stainless steel tubing that is separated by eleven valves to divide the tubing into 10 identical segments, but it can be easily adapted to collect smaller or larger samples. In the collection phase the SAS is directly connected to the outlet of an optical analyzer that measures the mole fractions of CO2, CH4 and CO from an AirCore sampler. The stratospheric part (or if desired any part of the AirCore air) is then directed through the SAS. When the SAS is filled with the selected air, the valves are closed and the vertical profile is maintained in the different segments of the SAS. The segments can later be analysed to retrieve vertical profiles of other trace gas signatures that require slower instrumentation. As an application, we describe the coupling of the SAS to an analytical system to determine the 17O excess of CO2, which is a tracer for photochemical processing of stratospheric air. For this purpose the analytical system described by Mrozek et al. (2015) was adapted for analysis of air directly from the SAS. The performance of the coupled system is demonstrated for a set of air samples from an AirCore flight in November 2014 near Sodankylä, Finland. The standard error for a 25 mL air sample at stratospheric CO2 mole fraction is 0.56 ‰ (1σ) for δ17O and 0.03 ‰ (1σ) for both δ18O and δ13C. Measured Δ17O(CO2) values show a clear correlation with N2O in agreement with already published data.

  19. Microbial counts and particulate matter levels in roadside air samples under skytrain stations, Bangkok, Thailand.

    PubMed

    Luksamijarulkul, Pipat; Kongtip, Pornpimol

    2010-05-01

    In conditions with heavy traffic and crowds of people on roadside areas under skytrain stations in Bangkok, the natural air ventilation may be insufficient and air quality may be poor. A study of 350 air samples collected from the roadside, under skytrain stations in Bangkok, was carried out to assess microbial counts (210 air samples) and particulate matter (PM10) levels (140 samples). The results reveal the mean +/- standard deviation bacterial counts and fungal counts were 406.8 +/- 302.7 cfu/m3 and 128.9 +/- 89.7 cfu/m3, respectively. The PM10 level was 186.1 +/- 188.1 microg/m3. When compared to recommended levels, 4.8% of air samples (10/210 samples) had bacterial counts more than recommended levels (> 1,000 cfu/ m3) and 27.1% (38/140 samples) had PM10 levels more than recommended levels (> 120 microg/m3). These may affect human health, especially of street venders who spend most of their working time in these areas.

  20. Marine Technician's Handbook, Instructions for Taking Air Samples on Board Ship: Carbon Dioxide Project.

    ERIC Educational Resources Information Center

    Keeling, Charles D.

    This booklet is one of a series intended to provide explicit instructions for the collection of oceanographic data and samples at sea. The methods and procedures described have been used by the Scripps Institution of Oceanography and found reliable and up-to-date. Instructions are given for taking air samples on board ship to determine the…

  1. Report on sampling and analysis of ambient air at the central waste complex

    SciTech Connect

    Stauffer, M., Fluor Daniel Hanford

    1997-02-13

    Over 160 ambient indoor air samples were collected from warehouses at the Central Waste Complex used for the storage of low- level radioactive and mixed wastes. These grab (SUMMA) samples were analyzed by gas chromatography-mass spectrometry using a modified EPA TO-14 procedure. The data from this survey suggest that several buildings had elevated concentrations of volatile organic compounds.

  2. DEVELOPMENT OF A SUB-SLAB AIR SAMPLING PROTOCOL TO SUPPORT ASSESSMENT OF VAPOR INTRUSION

    EPA Science Inventory

    The primary purpose of this research effort is to develop a methodology for sub-slab sampling to support the EPA guidance and vapor intrusion investigations after vapor intrusion has been established at a site. Methodologies for sub-slab air sampling are currently lacking in ref...

  3. EVALUATION OF THE FILTER PACK FOR LONG-DURATION SAMPLING OF AMBIENT AIR

    EPA Science Inventory

    A 14-week filter pack (FP) sampler evaluation field study was conducted at a site near Bondville, IL to investigate the impact of weekly sampling duration. Simultaneous samples were collected using collocated filter packs (FP) from two independent air quality monitoring networks...

  4. Development of a multicopter-carried whole air sampling apparatus and its applications in environmental studies.

    PubMed

    Chang, Chih-Chung; Wang, Jia-Lin; Chang, Chih-Yuan; Liang, Mao-Chang; Lin, Ming-Ren

    2016-02-01

    To advance the capabilities of probing chemical composition aloft, we designed a lightweight remote-controlled whole air sampling component (WASC) and integrated it into a multicopter drone with agile maneuverability to perform aerial whole air sampling. A field mission hovering over an exhaust shaft of a roadway tunnel to collect air samples was performed to demonstrate the applicability of the multicopter-carried WASC apparatus. Ten aerial air samples surrounding the shaft vent were collected by the multicopter-carried WASC. Additional five samples were collected manually inside the shaft for comparison. These samples were then analyzed in the laboratory for the chemical composition of 109 volatile organic compounds (VOCs), CH4, CO, CO2, or CO2 isotopologues. Most of the VOCs in the upwind samples (the least affected by shaft exhaust) were low in concentrations (5.9 ppbv for total 109 VOCs), posting a strong contrast to those in the shaft exhaust (235.8 ppbv for total 109 VOCs). By comparing the aerial samples with the in-shaft samples for chemical compositions, the influence of the shaft exhaust on the surrounding natural air was estimated. Through the aerial measurements, three major advantages of the multicopter-carried WASC were demonstrated: 1. The highly maneuverable multicopter-carried WASC can be readily deployed for three-dimensional environmental studies at a local scale (0-1.5 km); 2. Aerial sampling with superior sample integrity and preservation conditions can now be performed with ease; and 3. Data with spatial resolution for a large array of gaseous species with high precision can be easily obtained.

  5. Gas emission from the UO2 samples, containing fission products and burnable absorber

    NASA Astrophysics Data System (ADS)

    Kopytin, V. P.; Baranov, V. G.; Burlakova, M. A.; Tenishev, A. V.; Kuzmin, R. S.; Pokrovskiy, S. A.; Mikhalchik, V. V.

    2016-04-01

    The process gas released from the fuel pellets of uranium fuel during fuel burn-up reduces the thermal conductivity of the rod-shell gap, enhances hydrogen embrittlement of the cladding material, causes it's carbonization, as well as transport processes in the fuel. In this study a technique of investigating the thermal desorption of gases from the UO2 fuel material were perfected in the temperature range 300-2000 K for uniform sample heating rate of 15 K/min in vacuum. The characteristic kinetic dependences are acquired for the gas emission from UO2 samples, containing simulators of fission products (SFP) and the burnable neutron absorber (BNA). Depending on the amount of SFP and BNA contained in the sample thermal desorption gas spectra (TDGS) vary. The composition of emitted gas varies, as well as the number of peaks in the TDGS and the peaks shift to higher temperatures. This indicates that introduction of SFPs and BNA alters the sample material structure and cause the creation of so- called traps which have different bonding energies to the gases. The traps can be a grid of dislocations, voids, and contained in the UO2 matrix SFP and BNA. Similar processes will occur in the fuel pellets in the real conditions of the Nuclear Power Plant as well.

  6. Radial-firing optical fiber tip containing conical-shaped air-pocket for biomedical applications.

    PubMed

    Lee, Seung Ho; Ryu, Yong-Tak; Son, Dong Hoon; Jeong, Seongmook; Kim, Youngwoong; Ju, Seongmin; Kim, Bok Hyeon; Han, Won-Taek

    2015-08-10

    We report a novel radial-firing optical fiber tip containing a conical-shaped air-pocket fabricated by deforming a hollow optical fiber using electric arc-discharge process. The hollow optical fiber was fusion spliced with a conventional optical fiber, simultaneously deforming into the intagliated conical-shaped region along the longitudinal fiber-axis of the fiber due to the gradual collapse of the cavity of the hollow optical fiber. Then the distal-end of the hollow optical fiber was sealed by the additional arc-discharge in order to obstruct the inflow of an external bio-substance or liquid to the inner air surface during the surgical operations, resulting in the formation of encased air-pocket in the silica glass fiber. Due to the total internal reflection of the laser beam at the conical-shaped air surface, the laser beam (λ = 632.8 nm) was deflected to the circumferential direction up to 87 degree with respect to the fiber-axis.

  7. Pesticide detection in air samples from contrasted houses and in their inhabitants' hair.

    PubMed

    Raeppel, Caroline; Salquèbre, Guillaume; Millet, Maurice; Appenzeller, Brice M R

    2016-02-15

    In order to identify associations between indoor air contamination and human exposure to pesticides, hair samples from 14 persons (9 adults and 5 children below 12 years) were collected simultaneously with the air of their 5 contrasted houses. Three houses were situated in Alsace (France), one in Lorraine (France) and one in Luxembourg (Luxembourg). Houses were located in urban (n=3), semi-urban (n=1) and rural areas (n=1). Twenty five (25) pesticides were detected at least once in indoor air samples and 20 pesticides were detected at least once in hair samples. The comparison between hair and air samples for the same sampling periods shows that pesticides detected in the two matrices were not necessarily associated. Exposure profiles varied from one home to another but also between inhabitants of the same home, suggesting that exposure can be different between inhabitants of the same home. This study demonstrated the usefulness and the complementarity of hair analysis, for the personalized biomonitoring of people exposure to pesticides, and air analysis, for the identification of airborne exposure and house contamination.

  8. Analysis of quartz by FT-IR in air samples of construction dust.

    PubMed

    Virji, M Abbas; Bello, Dhimiter; Woskie, Susan R; Liu, X Michael; Kalil, Andrew J

    2002-03-01

    The construction industry is reported to have some of the highest exposures to silica-containing dust. With the designation of crystalline silica as a group I human carcinogen by the International Agency for Research on Cancer (IARC), there exists a need for an analytical method to accurately quantify low levels of quartz. A method is described that uses FT-IR for quartz analysis of personal air samples collected from heavy and highway construction sites using 4-stage personal impactors. Sample filters were ashed and 13-mm or 5-mm pellets were prepared. Absorbance spectra were collected using FT-IR at resolution of 1 cm(-1) and 64 scans per spectrum. Two spectra were collected per sample using the appropriate background spectrum subtraction. Spectral manipulations such as Fourier self-deconvolution and derivatizations were performed to improve quantification. Peak height for quartz was measured at 798 cm(-1) for quantitative analysis. The estimated limit of detection for the 5-mm pellets was 1.3 microg. Recoveries of Min-U-Sil 5 spikes showed an average of > or = 94 percent for the two pellet types. The coefficient of variation of the 5-mm pellet was 9 percent at 6 microg quartz load, and 7 percent at 62 microg load. Interferences from clay, amorphous silica, concrete, calcite, and kaolinite were investigated, these being the more likely sources of interferences in construction environment. Spikes of mixtures of amorphous silica or kaolinite with Min-U-Sil 5 showed both contaminants introduced, on average, a positive error of < 5 microg with average recoveries of 106 percent and 111 percent, respectively. Spikes of mixtures of clay or concrete with Min-U-Sil 5 showed overall average recovery of 100 percent and 90 percent, respectively, after accounting for the presence of quartz in clay and concrete. This method can quantify low levels of quartz with reasonable accuracy in the face of common contaminants found in the construction industry.

  9. Comparison of mold concentrations quantified by MSQPCR in indoor and outdoor air sampled simultaneously

    SciTech Connect

    Meklin, Teija; Reponen, Tina; McKinstry, Craig A.; Cho, Seung H.; Grinshpun, Sergey A.; Nevalainen, Aino; Vepsalainen, Asko; Haugland, Richard A.; Lemasters, Grace; Vesper, Sephen J.

    2007-08-15

    Mold specific quantitative PCR (MSQPCR) was used to measure the concentrations of 36 mold species in dust and in indoor and in outdoor air samples that were taken simultaneously in 17 homes in Cincinnati with no-known water damage. The total spore concentrations in the indoor (I) and outdoor (O) air samples were statistically significantly different and the concentrations in the three sample types of many of the individual species were significantly different (p < 0.05 based on the Wilcoxon Signed Rank Test). The I/O ratios of the averages or geometric means of the individual species were generally less than 1; but these I/O ratios were quite variable ranging from 0.03 for A. sydowii to 1.2 for Acremonium strictum. There were no significant correlations for the 36 specific mold concentrations between the dust samples and the indoor or outdoor air samples (based on the Spearman’s Rho test). The indoor and outdoor air concentrations of 32 of the species were not correlated. Only Aspergillus penicillioides, C. cladosporioides types 1 and 2 and C. herbarum had sufficient data to estimate a correlation at rho > 0.5 with signicance (p < 0.05) In six of these homes, a previous dust sample had been collected and analyzed 2 years earlier. The ERMI© values for the dust samples taken in the same home two years apart were not significantly different (p=0.22) based on Wilcoxon Signed Rank Test.

  10. Field evaluation of sampling and analysis for organic pollutants in indoor air

    SciTech Connect

    Chuang, J.C.; Mack, G.A.; Stockrahm, J.W.; Hannan, S.W.; Bridges, C.

    1988-08-01

    The objectives of the study were to determine the feasibility of the use of newly developed indoor air samplers in residential indoor air sampling and to evaluate methodology for characterization of the concentrations of polynuclear aromatic hydrocarbons (PAH), PAH derivatives, and nicotine in residential air. Residential air sampling was conducted in Columbus, Ohio during the winter of 1986/87. The PAH derivatives were found at much lower levels than their parent PAH. Higher average indoor levels of all but three target compounds were found compared to outdoor levels. The higher outdoor levels of these three compounds (naphthalene dicarboxylic acid anhydride, pyrene dicarboxylic acid anhydride, and 2-nitrofluoranthene) are probably due to atmospheric transformation. Cigarette smoking was identified as the most-significant contributor to indoor levels of PAH and PAH derivatives. Homes with gas-heating systems appeared to have higher pollutant levels compared to homes with electric-heating systems.

  11. A Comprehensive Assessment of Biologicals Contained Within Commercial Airliner Cabin Air

    NASA Technical Reports Server (NTRS)

    LaDuc, Myron T.; Osman, Shariff; Dekas, Anne; Stuecker, Tara; Newcombe, Dave; Piceno, Yvette; Fuhrman, J.; Andersen, Gary; Venkateswaran, Kasthuri; Bearman, Greg

    2006-01-01

    Both culture-based and culture-independent, biomarker-targeted microbial enumeration and identification technologies were employed to estimate total microbial and viral burden and diversity within the cabin air of commercial airliners. Samples from each of twenty flights spanning three commercial carriers were collected via air-impingement. When the total viable microbial population was estimated by assaying relative concentrations of the universal energy carrier ATP, values ranged from below detection limits (BDL) to 4.1 x 106 cells/cubic m of air. The total viable microbial population was extremely low in both of Airline A (approximately 10% samples) and C (approximately 18% samples) compared to the samples collected aboard flights on Airline A and B (approximately 70% samples). When samples were collected as a function of time over the course of flights, a gradual accumulation of microbes was observed from the time of passenger boarding through mid-flight, followed by a sharp decline in microbial abundance and viability from the initiation of descent through landing. It is concluded in this study that only 10% of the viable microbes of the cabin air were cultivable and suggested a need to employ state-of-the art molecular assay that measures both cultivable and viable-but-non-cultivable microbes. Among the cultivable bacteria, colonies of Acinetobacter sp. were by far the most profuse in Phase I, and Gram-positive bacteria of the genera Staphylococcus and Bacillus were the most abundant during Phase II. The isolation of the human pathogens Acinetobacter johnsonii, A. calcoaceticus, Janibacter melonis, Microbacterium trichotecenolyticum, Massilia timonae, Staphylococcus saprophyticus, Corynebacterium lipophiloflavum is concerning, as these bacteria can cause meningitis, septicemia, and a handful of sometimes fatal diseases and infections. Molecular microbial community analyses exhibited presence of the alpha-, beta-, gamma-, and delta- proteobacteria, as well as

  12. Air Sample Conditioner Helps the Waste Treatment Plant Meet Emissions Standards

    SciTech Connect

    Glissmeyer, John A.; Flaherty, Julia E.; Pekour, Mikhail S.

    2014-12-02

    The air in three of the Hanford Site Waste Treatment and Immobilization Plant (WTP) melter off-gas discharge stacks will be hot and humid after passing through the train of emission abatement equipment. The off-gas temperature and humidity levels will be incompatible with the airborne emissions monitoring equipment required for this type of stack. To facilitate sampling from these facilities, an air sample conditioner system will be installed to introduce cool, dry air into the sample stream to reduce the temperature and dew point. This will avoid thermal damage to the instrumentation and problematic condensation. The complete sample transport system must also deliver at least 50% of the particles in the sample airstream to the sample collection and on-line analysis equipment. The primary components of the sample conditioning system were tested in a laboratory setting. The sample conditioner itself is based on a commercially-available porous tube filter design. It consists of a porous sintered metal tube inside a coaxial metal jacket. The hot gas sample stream passes axially through the porous tube, and the dry, cool air is injected into the jacket and through the porous wall of the inner tube, creating an effective sample diluter. The dilution and sample air mix along the entire length of the porous tube, thereby simultaneously reducing the dew point and temperature of the mixed sample stream. Furthermore, because the dilution air enters through the porous tube wall, the sample stream does not come in contact with the porous wall and particle deposition is reduced in this part of the sampling system. Tests were performed with an environmental chamber to supply air with the temperature and humidity needed to simulate the off-gas conditions. Air from the chamber was passed through the conditioning system to test its ability to reduce the temperature and dew point of the sample stream. To measure particle deposition, oil droplets in the range of 9 to 11 micrometer

  13. Comparison of sampling methods for radiocarbon dating of carbonyls in air samples via accelerator mass spectrometry

    NASA Astrophysics Data System (ADS)

    Schindler, Matthias; Kretschmer, Wolfgang; Scharf, Andreas; Tschekalinskij, Alexander

    2016-05-01

    Three new methods to sample and prepare various carbonyl compounds for radiocarbon measurements were developed and tested. Two of these procedures utilized the Strecker synthetic method to form amino acids from carbonyl compounds with either sodium cyanide or trimethylsilyl cyanide. The third procedure used semicarbazide to form crystalline carbazones with the carbonyl compounds. The resulting amino acids and semicarbazones were then separated and purified using thin layer chromatography. The separated compounds were then combusted to CO2 and reduced to graphite to determine 14C content by accelerator mass spectrometry (AMS). All of these methods were also compared with the standard carbonyl compound sampling method wherein a compound is derivatized with 2,4-dinitrophenylhydrazine and then separated by high-performance liquid chromatography (HPLC).

  14. Report on sampling and analysis of air at trenches 218-W-4C and218-W-5 {number_sign}31 of the low level burial grounds

    SciTech Connect

    Stauffer, M.

    1997-10-06

    This report presents analytical results of air samples collected from trenches at the Low Level Burial Grounds. The samples were collected with SUMMA canisters and were analyzed by gas chromatography-mass spectrometry using a modified EPA TO-14 procedure. The data suggest that the vent pipes of the 218-W-4C trenches had elevated concentrations of volatile organic compounds. The ambient air samples collected at the 218-W-5 {number_sign}31 facility, an open trench that does not contain any waste at this time, did not show any target compounds above the method detection limit.

  15. The combined effects of sampling parameters on the sorbent tube sampling of phthalates in air

    PubMed Central

    Jo, Sang-Hee; Kim, Ki-Hyun; Kwon, Kyenghee

    2017-01-01

    The adsorption properties of various sorbent materials were investigated to assess the factors affecting biases in the sorbent tube (ST) sampling of airborne phthalates. The recovery of phthalates was assessed critically in relation to four key sampling parameters: (1) three types of sorbent materials (quartz wool (QW), glass wool (GW), and quartz wool plus Tenax TA (QWTN)), (2) the concentration level of phthalate standards, (3) purge flow rate, and (4) purge volume for analysis based on a ‘sorbent tube-thermal desorption-gas chromatography-mass spectrometry (ST-TD-GC-MS)’ system. Among these parameters, the type of ST was the most influential in determining the recovery of phthalates. For a given ST type, the recovery of phthalates tends to improve with increases in the concentration level of standards. In case of QW and QWTN tubes, the breakthrough of phthalates was not observed up to the maximum purge volume (100 L) tested in this work; however, in case of GW, the recovery decreased drastically to 60% even at a purge volume of 1 L for low molecular weight phthalates. The results of our study demonstrate that accurate analysis of airborne phthalates can be achieved through proper control of key sampling parameters, particularly the choice of sorbent material. PMID:28361993

  16. Quantitative detection system for maize sample containing combined-trait genetically modified maize.

    PubMed

    Akiyama, Hiroshi; Watanabe, Takahiro; Wakabayashi, Kaoru; Nakade, Shinsuke; Yasui, Shuji; Sakata, Kozue; Chiba, Ryoko; Spiegelhalter, Frank; Hino, Akihiro; Maitani, Tamio

    2005-11-15

    Various countries have established regulations that stipulate the labeling of agricultural commodities, feed, and food products that contain or are made from genetically modified (GM) material or that contain adventitious GM material in amounts that exceed certain threshold levels. While regulations in some countries refer to GM material on a weight per weight (w/w) percentage, the currently applied detection methods do not directly measure the w/w percentage of the GM material. Depending on the particular method and the sample matrix it is applied to, the conversion of analytical results to a w/w percentage is challenging or not possible. The first rapid PCR system for GM maize detection on a single kernel basis has been developed. The equipment for the grinding of individual kernels and a silica membrane-based 96-well DNA extraction kit were both significantly revised and optimized for this particular purpose, respectively. We developed a multiplex real-time PCR method for the rapid quantification of GM DNA sequences in the obtained DNA solutions. In addition, a multiplex qualitative PCR detection method allows for the simultaneous detection of different GM maize traits in each kernel and thereby for identification of individual kernels that contain a combination of two or more GM traits. Especially for grain samples that potentially contain combined-trait GM maize kernels, the proposed methods can deliver informative results in a rapid, precise, and reliable manner.

  17. Air bearing center cross gap of neutron stress spectrometer sample table support system

    NASA Astrophysics Data System (ADS)

    Li, Yang; Wu, Yunxin; Gong, Hai; Feng, Xiaolei

    2016-12-01

    A support system is the main load-bearing component of sample table for neutron stress spectrometer, and air bearing is an important element of a support system. The neutron stress spectrometer sample table was introduced, and the scheme for air bearing combination was selected. To study the performance of air bearing center cross gap, finite element models (FEMs) were established based on air motion and Reynolds equations, effects of air supply pressure, and gap parameters on the overturning moment and bearing capacity of air bearing center cross gap were analyzed. Results indicate that the width, depth, and height differences of the marble floor gap played important roles in the performance of the air bearing. When gap width is lesser than 1 mm and gap depth is lower than 0.4 mm, bearing capacity and overturning moment would vary rapidly with the variation of the width and depth. A gap height difference results in the bearing capacity dropping rapidly. The FEM results agree well with experimental results. Further, findings of the study could guide the design of the support system and marble floor.

  18. Investigation of spray characteristics for flashing injection of fuels containing dissolved air and superheated fuels

    NASA Technical Reports Server (NTRS)

    Solomon, A. S. P.; Chen, L. D.; Faeth, G. M.

    1982-01-01

    The flow, atomization and spreading of flashing injector flowing liquids containing dissolved gases (jet/air) as well as superheated liquids (Freon II) were considered. The use of a two stage expansion process separated by an expansion chamber, ws found to be beneficial for flashing injection particularly for dissolved gas systems. Both locally homogeneous and separated flow models provided good predictions of injector flow properties. Conventional correlations for drop sizes from pressure atomized and airblast injectors were successfully modified, using the separated flow model to prescribe injector exit conditions, to correlate drop size measurements. Additional experimental results are provided for spray angle and combustion properties of sprays from flashing injectors.

  19. Fast neutron radiography scanner for the detection of contraband in air cargo containers.

    PubMed

    Eberhardt, J E; Rainey, S; Stevens, R J; Sowerby, B D; Tickner, J R

    2005-08-01

    There is a growing need to rapidly scan bulk air cargo for contraband such as illicit drugs and explosives. The Commonwealth Science and Industrial Research Organisation (CSIRO) have been working with Australian Customs Service to develop a scanner capable of directly scanning airfreight containers in 1--2 minutes without unpacking. The scanner combines fast neutron and gamma-ray radiography to provide high-resolution images that include information on material composition. A full-scale prototype scanner has been successfully tested in the laboratory and a commercial-scale scanner is due to be installed at Brisbane airport in 2005.

  20. Sampling technologies and air pollution control devices for gaseous and particulate arsenic: a review.

    PubMed

    Helsen, Lieve

    2005-09-01

    Direct measurement of arsenic release requires a good sampling and analysis procedure in order to capture and detect the total amount of metals emitted. The literature is extensively reviewed in order to evaluate the efficiency of full field-scale and laboratory scale techniques for capturing particulate and gaseous emissions of arsenic from the thermo-chemical treatment of different sources of arsenic. Furthermore, trace arsenic concentrations in ambient air, national standard sampling methods and arsenic analysis methods are considered. Besides sampling techniques, the use of sorbents is also reviewed with respect to both approaches (1) to prevent the metals from exiting with the flue gas and (2) to react or combine with the metals in order to be collected in air pollution control systems. The most important conclusion is that submicron arsenic fumes are difficult to control in conventional air pollution control devices. Complete capture of the arsenic species requires a combination of particle control and vapour control devices.

  1. Use of a Radon Stripping Algorithm for Retrospective Assessment of Air Filter Samples

    SciTech Connect

    Robert Hayes

    2009-01-23

    An evaluation of a large number of air sample filters was undertaken using a commercial alpha and beta spectroscopy system employing a passive implanted planar silicon (PIPS) detector. Samples were only measured after air flow through the filters had ceased. Use of a commercial radon stripping algorithm was implemented to discriminate anthropogenic alpha and beta activity on the filters from the radon progeny. When uncontaminated air filters were evaluated, the results showed that there was a time-dependent bias in both average estimates and measurement dispersion with the relative bias being small compared to the dispersion. By also measuring environmental air sample filters simultaneously with electroplated alpha and beta sources, use of the radon stripping algorithm demonstrated a number of substantial unexpected deviations. Use of the current algorithm is therefore not recommended for assay applications and so use of the PIPS detector should only be utilized for gross counting without appropriate modifications to the curve fitting algorithm. As a screening method, the radon stripping algorithm might be expected to see elevated alpha and beta activities on air sample filters (not due to radon progeny) around the 200 dpm level.

  2. A Method for Selective Enrichment and Analysis of Nitrotyrosine-Containing Peptides in Complex Proteome Samples

    SciTech Connect

    Zhang, Qibin; Qian, Weijun; Knyushko, Tanya V.; Clauss, Therese RW; Purvine, Samuel O.; Moore, Ronald J.; Sacksteder, Colette A.; Chin, Mark H.; Smith, Desmond J.; Camp, David G.; Bigelow, Diana J.; Smith, Richard D.

    2007-06-01

    Elevated levels of protein tyrosine nitration have been found in various neurodegenerative diseases and aging related pathologies; however, the lack of an efficient enrichment method has prevented the analysis of this important low level protein modification. We have developed an efficient method for specific enrichment of nitrotyrosine containing peptides that permits nitrotyrosine peptides and specific nitration sites to be unambiguously identified with LC-MS/MS. The method is based on the derivatization of nitrotyrosine into free sulfhydryl groups followed by high efficiency enrichment of sulfhydryl-containing peptides with thiopropyl sepharose beads. The derivatization process starts with acetylation with acetic anhydride to block all primary amines, followed by reduction of nitrotyrosine to aminotyrosine, then derivatization of aminotyrosine with N-Succinimidyl S-Acetylthioacetate (SATA), and finally deprotecting of S-acetyl on SATA to form free sulfhydryl groups. This method was evaluated using nitrotyrosine containing peptides, in-vitro nitrated human histone 1.2, and bovine serum albumin (BSA). 91% and 62% of the identified peptides from enriched histone and BSA samples were nitrotyrosine derivatized peptides, respectively, suggesting relative high specificity of the enrichment method. The application of this method to in-vitro nitrated mouse brain homogenate resulted in 35% of identified peptides containing nitrotyrosine (compared to only 5.9% observed from the global analysis of unenriched sample), and a total of 150 unique nitrated peptides covering 102 proteins were identified with a false discovery rate estimated at 3.3% from duplicate LC-MS/MS analyses of a single enriched sample.

  3. Use of Whatman-41 filters in air quality sampling networks (with applications to elemental analysis)

    NASA Technical Reports Server (NTRS)

    Neustadter, H. E.; Sidik, S. M.; King, R. B.; Fordyce, J. S.; Burr, J. C.

    1974-01-01

    The operation of a 16-site parallel high volume air sampling network with glass fiber filters on one unit and Whatman-41 filters on the other is reported. The network data and data from several other experiments indicate that (1) Sampler-to-sampler and filter-to-filter variabilities are small; (2) hygroscopic affinity of Whatman-41 filters need not introduce errors; and (3) suspended particulate samples from glass fiber filters averaged slightly, but not statistically significantly, higher than from Whatman-41-filters. The results obtained demonstrate the practicability of Whatman-41 filters for air quality monitoring and elemental analysis.

  4. Mitigating factors on air concentrations of radon emanating from different granite samples

    SciTech Connect

    Qari, T.M.; Mamoon, A.M.; Abdul-Fattah, A.F. )

    1991-11-01

    Continuous exposure to increased air concentrations of radon in living areas is to be avoided according to the Environmental Protection Agency (EPA) and several published reports. Radon concentrations in ambient air are influenced by several factors related to the nature of the radon source itself, environmental conditions, and the presence of mitigating factors, if any. In this study, crushed granite samples of different types, particle diameters, and moisture contents were compared in simplified test systems with regard to radon emanation from the samples. The effects of selected mitigating factors, namely, ventilation and different barriers to diffusion of emanated radon were determined.

  5. Cleanliness of common air sampling sorbents for application to phenolic compounds measurement using supercritical fluid extraction

    SciTech Connect

    Bowyer, J.R.; Pleil, J.D.

    1994-12-31

    The trace-level measurement of phenolic compounds in the ambient air is complicated by the acidic and polar nature of the compounds especially during recovery from the sampling medium. Recently, supercritical fluid extraction (SFE) has been proposed as an alternative extraction method to Soxhlet extraction or thermal desorption to achieve more efficient recoveries. For such methodology to become practical, the candidate sorbents must first be tested for stability and cleanliness under SFE conditions. This paper describes exploratory research results of background contamination tests and cleanup properties of some common air sampling sorbent media with respect to future application to phenolic compounds monitoring.

  6. Cleanliness of common air sampling sorbents for application to phenolic compounds measurement using supercritical fluid extraction

    SciTech Connect

    Bowyer, J.R.; Pleil, J.D.

    1994-01-01

    The trace-level measurement of phenolic compounds in the ambient air is complicated by the acidic and polar nature of the compounds especially during recovery from the sampling medium. Recently, supercritical fluid extraction (SFE) has been proposed as an alternative extraction method to Soxhlet extraction or thermal desorption to achieve more efficient recoveries. For such methodology to become practical, the candidate sorbents must first be tested for stability and cleanliness under SFE conditions. The paper describes exploratory research results of background contamination tests and cleanup properties of some common air sampling sorbent media with respect to future application to phenolic compounds monitoring.

  7. Monitoring organic nitrogen species in the UT/LS - a new system for analysis of CARIBIC whole air samples

    NASA Astrophysics Data System (ADS)

    Sauvage, Carina; Thorenz, Ute; Baker, Angela; Brenninkmeijer, Carl; Williams, Jonathan

    2014-05-01

    The CARIBIC project is a unique program for long term and global scale monitoring of the atmosphere (http://www.caribic-atmospheric.com). An instrument container is installed monthly into a civil aircraft operated by Lufthansa (Airbus A 340-600) and makes atmospheric observations en route from Frankfurt, Germany to various destinations around the globe. In four to six long distance flights at a cruising altitude of 10 to 12 km online measurements of various atmospheric tracers are performed during the flight as well as whole air samples are taken with two different sampling units (116 samples in both glass and stainless steel canisters). These samples are routinely analyzed for greenhouse gases, non-methane hydrocarbons (NMHC) and halogenated compounds. Nitrogen containing compounds play various important roles in the atmosphere. Alkyl nitrates (RONO2) are products of the reaction of NMHC with OH and other oxidants in the presence of NO. They can provide information on the oxidative history of an air mass. Moreover they influence photolchemical ozone formation and act as a transport mechanism for reactive nitrogen. Less reactive nitrogen containing species such as HCN and acetonitrile are important markers for biomass burning, while organic amines are involved in gas to particle partitioning. Finally N2O is a long lived nitrogen containing gas important for the Earth's radiative budget. Regular measurements of such nitrogen compounds would therefore be a significant contribution to the CARIBIC data set. Especially for high altitude samples, in which the mixing ratios of many species are expected to be in the low ppt range, a highly sensitive method for analysis is required. Therefore a new system for measurement of nitrogen compounds has been built up, comprising a gas chromatograph (GC) using a nitrogen chemiluminescence detector (NCD). An important advantage of the NCD is that it is selective for nitrogen and equimolar. The nitrogen compounds are sequentially pre

  8. Detection of Mycoplasma hyopneumoniae by Air Sampling with a Nested PCR Assay

    PubMed Central

    Stärk, Katharina D. C.; Nicolet, Jacques; Frey, Joachim

    1998-01-01

    This article describes the first successful detection of airborne Mycoplasma hyopneumoniae under experimental and field conditions with a new nested PCR assay. Air was sampled with polyethersulfone membranes (pore size, 0.2 μm) mounted in filter holders. Filters were processed by dissolution and direct extraction of DNA for PCR analysis. For the PCR, two nested pairs of oligonucleotide primers were designed by using an M. hyopneumoniae-specific DNA sequence of a repeated gene segment. A nested PCR assay was developed and used to analyze samples collected in eight pig houses where respiratory problems had been common. Air was also sampled from a mycoplasma-free herd. The nested PCR was highly specific and 104 times as sensitive as a one-step PCR. Under field conditions, the sampling system was able to detect airborne M. hyopneumoniae on 80% of farms where acute respiratory disease was present. No airborne M. hyopneumoniae was detected on infected farms without acute cases. The chance of successful detection was increased if air was sampled at several locations within a room and at a lower air humidity. PMID:9464391

  9. Passive dosimeters for nitrogen dioxide in personal/indoor air sampling: A review

    PubMed Central

    Yu, Chang Ho; Morandi, Maria T.; Weisel, Clifford P.

    2015-01-01

    Accurate measurement of nitrogen dioxide concentrations in both outdoor and indoor environments, including personal exposures, is a fundamental step for linking atmospheric nitrogen dioxide levels to potential health and ecological effects. The measurement has been conducted generally in two ways: active (pumped) sampling and passive (diffusive) sampling. Diffusion samplers, initially developed and used for workplace air monitoring, have been found to be useful and cost-effective alternatives to conventional pumped samplers for monitoring ambient, indoor and personal exposures at the lower concentrations found in environmental settings. Since the 1970s, passive samplers have been deployed for ambient air monitoring in urban and rural sites, and to determine personal and indoor exposure to NO2. This article reviews the development of NO2 passive samplers, the sampling characteristics of passive samplers currently available, and their application in ambient and indoor air monitoring and personal exposure studies. The limitations and advantages of the various passive sampler geometries (i.e., tube, badge, and radial type) are also discussed. This review provides researchers and risk assessors with practical information about NO2 passive samplers, especially useful when designing field sampling strategies for exposure and indoor/outdoor air sampling. PMID:18446185

  10. An Alternative to Performing Remote-Handled Transuranic Waste Container Headspace Gas Sampling and Analysis

    SciTech Connect

    Spangler, L. R.; Djordjevic, S. M.; Kehrman, R. F.; Most, W. A.

    2002-02-26

    The Waste Isolation Pilot Plant (WIPP) is operating under a Resource Conservation and Recovery Act (RCRA) Hazardous Waste Facility Permit (HWFP) for contact-handled (CH) transuranic (TRU) waste. The HWFP contains limitations on allowable emissions from waste disposed in the underground. This environmental performance standard imposed on the WIPP consists of limiting volatile organic compound (VOC) emissions from emplaced waste to ensure protection of human health and the environment. The standard is currently met by tracking individual waste container headspace gas concentrations, which are determined by headspace gas sampling and analysis of CH TRU waste containers. The WIPP is seeking a HWFP modification to allow the disposal of remote-handled (RH) TRU waste. Because RH TRU waste is limited to approximately 5% of the waste volume and is emplaced in the disposal room walls, it is possible to bound the potential RH TRU waste contribution to VOC emissions using conservative upper bounds. These conservative upper bounds were developed as an alternative to RH TRU waste canister headspace gas sampling and analysis. The methodology used to perform the calculations used to evaluate VOC emissions from emplaced RH TRU waste canisters applied the same equations as those used to evaluate VOC emissions in the original HWFP application.

  11. Hayabusa2 Sample Catcher and Container: Metal-Seal System for Vacuum Encapsulation of Returned Samples with Volatiles and Organic Compounds Recovered from C-Type Asteroid Ryugu

    NASA Astrophysics Data System (ADS)

    Okazaki, Ryuji; Sawada, Hirotaka; Yamanouchi, Shinji; Tachibana, Shogo; Miura, Yayoi N.; Sakamoto, Kanako; Takano, Yoshinori; Abe, Masanao; Itoh, Shoichi; Yamada, Keita; Yabuta, Hikaru; Okamoto, Chisato; Yano, Hajime; Noguchi, Takaaki; Nakamura, Tomoki; Nagao, Keisuke

    2016-10-01

    The spacecraft Hayabusa2 was launched on December 3, 2014, to collect and return samples from a C-type asteroid, 162173 Ryugu (provisional designation, 1999 JU3). It is expected that the samples collected contain organic matter and water-bearing minerals and have key information to elucidate the origin and history of the Solar System and the evolution of bio-related organics prior to delivery to the early Earth. In order to obtain samples with volatile species without terrestrial contamination, based on lessons learned from the Hayabusa mission, the sample catcher and container of Hayabusa2 were refined from those used in Hayabusa. The improvements include (1) a mirror finish of the inner wall surface of the sample catcher and the container, (2) adoption of an aluminum metal sealing system, and (3) addition of a gas-sampling interface for gas collection and evacuation. The former two improvements were made to limit contamination of the samples by terrestrial atmosphere below 1 Pa after the container is sealed. The gas-sampling interface will be used to promptly collect volatile species released from the samples in the sample container after sealing of the container. These improvements maintain the value of the returned samples.

  12. PRN 93-4: Ban on Aerosol Products Containing CFCs and HCFCs under the Clean Air Act

    EPA Pesticide Factsheets

    This notice alerts pesticide registrants to a rule under the Clean Air Act banning distribution and sale of aerosol and pressurized products, including pesticide products, that contain chlorofluorocarbons (CFCs).

  13. Solubility testing of actinides on breathing-zone and area air samples

    SciTech Connect

    Metzger, R.L.; Jessop, B.H.; McDowell, B.L.

    1996-02-01

    A solubility testing method for several common actinides has been developed with sufficient sensitivity to allow profiles to be determined from routine breathing zone and area air samples in the workplace. Air samples are covered with a clean filter to form a filter-sample-filter sandwich which is immersed in an extracellular lung serum simulant solution. The sample is moved to a fresh beaker of the lung fluid simulant each day for one week, and then weekly until the end of the 28 day test period. The soak solutions are wet ashed with nitric acid and hydrogen peroxide to destroy the organic components of the lung simulant solution prior to extraction of the nuclides of interest directly into an extractive scintillator for subsequent counting on a Photon-Electron Rejecting Alpha Liquid Scintillation (PERALS{reg_sign}) spectrometer. Solvent extraction methods utilizing the extractive scintillators have been developed for the isotopes of uranium, plutonium, and curium. The procedures normally produce an isotopic recovery greater than 95% and have been used to develop solubility profiles from air samples with 40 pCi or less of U{sub 3}O{sub 8}. Profiles developed for U{sub 3}O{sub 8} samples show good agreement with in vitro and in vivo tests performed by other investigators on samples from the same uranium mills.

  14. Recommended Mass Spectrometry-Based Strategies to Identify Ricin-Containing Samples

    PubMed Central

    Kalb, Suzanne R.; Schieltz, David M.; Becher, François; Astot, Crister; Fredriksson, Sten-Åke; Barr, John R.

    2015-01-01

    Ricin is a protein toxin produced by the castor bean plant (Ricinus communis) together with a related protein known as R. communis agglutinin (RCA120). Mass spectrometric (MS) assays have the capacity to unambiguously identify ricin and to detect ricin’s activity in samples with complex matrices. These qualitative and quantitative assays enable detection and differentiation of ricin from the less toxic RCA120 through determination of the amino acid sequence of the protein in question, and active ricin can be monitored by MS as the release of adenine from the depurination of a nucleic acid substrate. In this work, we describe the application of MS-based methods to detect, differentiate and quantify ricin and RCA120 in nine blinded samples supplied as part of the EQuATox proficiency test. Overall, MS-based assays successfully identified all samples containing ricin or RCA120 with the exception of the sample spiked with the lowest concentration (0.414 ng/mL). In fact, mass spectrometry was the most successful method for differentiation of ricin and RCA120 based on amino acid determination. Mass spectrometric methods were also successful at ranking the functional activities of the samples, successfully yielding semi-quantitative results. These results indicate that MS-based assays are excellent techniques to detect, differentiate, and quantify ricin and RCA120 in complex matrices. PMID:26610568

  15. Recommended Mass Spectrometry-Based Strategies to Identify Ricin-Containing Samples.

    PubMed

    Kalb, Suzanne R; Schieltz, David M; Becher, François; Astot, Crister; Fredriksson, Sten-Åke; Barr, John R

    2015-11-25

    Ricin is a protein toxin produced by the castor bean plant (Ricinus communis) together with a related protein known as R. communis agglutinin (RCA120). Mass spectrometric (MS) assays have the capacity to unambiguously identify ricin and to detect ricin's activity in samples with complex matrices. These qualitative and quantitative assays enable detection and differentiation of ricin from the less toxic RCA120 through determination of the amino acid sequence of the protein in question, and active ricin can be monitored by MS as the release of adenine from the depurination of a nucleic acid substrate. In this work, we describe the application of MS-based methods to detect, differentiate and quantify ricin and RCA120 in nine blinded samples supplied as part of the EQuATox proficiency test. Overall, MS-based assays successfully identified all samples containing ricin or RCA120 with the exception of the sample spiked with the lowest concentration (0.414 ng/mL). In fact, mass spectrometry was the most successful method for differentiation of ricin and RCA120 based on amino acid determination. Mass spectrometric methods were also successful at ranking the functional activities of the samples, successfully yielding semi-quantitative results. These results indicate that MS-based assays are excellent techniques to detect, differentiate, and quantify ricin and RCA120 in complex matrices.

  16. Tell ';Em Early and Often: Communicating About Mars Sample Return Containment and Biohazard Testing

    NASA Astrophysics Data System (ADS)

    Rummel, J. D.; Race, M. S.

    2013-12-01

    The recent report of the Mars 2020 Science Definition Team recommended that the mission accomplish broad and rigorous in situ science, including seeking biosignatures and acquiring a diverse set of samples intended to be stored in a cache for potential return to Earth at a later time. In developing the Mars 2020 mission NASA and its partners are beginning at least the promise (uncertainty #1) of a later sample return and will need to address important uncertainties with implications not only for the integrity of science, but also for public communication about the mission and associated decision making. In particular, they will have to address the requirement, reaffirmed by multiple US National Research Council reports, to contain such a sample when it is returned (uncertainty #2) and not release it, unsterilized (uncertainty #3), until tests prove that it does not contain a biohazard (uncertainty #4). And of course we won't know what the samples are like until they are collected (uncertainty #5, et al.). In an ongoing process of scientific analysis and protocol development, NASA and its partners (such as the European Space Agency) have continued to discuss the requirements for containment and how it should be defined and implemented at a high (how high?) degree of certainty. How the protocol and requirements will be finalized, and how the decision process to approve them will be structured are all part of a communications picture that changes not only based on the technical aspects of the mission, but on other public events that may have little or nothing to do with the exploration of space. Now that the Mars 2020 mission has been moved forward as the first step in a sample-return train, NASA will face a robust communications challenge that will not only be complicated by the uncertainties numbered above, but by the uncertainties associated with any large-budget science program that depends on public funding, a situation fraught with its own uncertainties, to be

  17. Professional judgment and the interpretation of viable mold air sampling data.

    PubMed

    Johnson, David; Thompson, David; Clinkenbeard, Rodney; Redus, Jason

    2008-10-01

    Although mold air sampling is technically straightforward, interpreting the results to decide if there is an indoor source is not. Applying formal statistical tests to mold sampling data is an error-prone practice due to the extreme data variability. With neither established exposure limits nor useful statistical techniques, indoor air quality investigators often must rely on their professional judgment, but the lack of a consensus "decision strategy" incorporating explicit decision criteria requires professionals to establish their own personal set of criteria when interpreting air sampling data. This study examined the level of agreement among indoor air quality practitioners in their evaluation of airborne mold sampling data and explored differences in inter-evaluator assessments. Eighteen investigators independently judged 30 sets of viable mold air sampling results to indicate: "definite indoor mold source," "likely indoor mold source," "not enough information to decide," "likely no indoor mold source," or "definitely no indoor mold source." Kappa coefficient analysis indicated weak inter-observer reliability, and comparison of evaluator mean scores showed clear inter-evaluator differences in their overall scoring patterns. The responses were modeled on indicator "traits" of the data sets using a generalized, linear mixed model approach and showed several traits to be associated with respondents' ratings, but they also demonstrated distinct and divergent inter-evaluator response patterns. Conclusions were that there was only weak overall agreement in evaluation of the mold sampling data, that particular traits of the data were associated with the conclusions reached, and that there were substantial inter-evaluator differences that were likely due to differences in the personal decision criteria employed by the individual evaluators. The overall conclusion was that there is a need for additional work to rigorously explore the constellation of decision criteria

  18. ENVIRONMENTAL SAMPLING USING LOCATION SPECIFIC AIR MONITORING IN BULK HANDLING FACILITIES

    SciTech Connect

    Sexton, L.; Hanks, D.; Degange, J.; Brant, H.; Hall, G.; Cable-Dunlap, P.; Anderson, B.

    2011-06-07

    Since the introduction of safeguards strengthening measures approved by the International Atomic Energy Agency (IAEA) Board of Governors (1992-1997), international nuclear safeguards inspectors have been able to utilize environmental sampling (ES) (e.g. deposited particulates, air, water, vegetation, sediments, soil and biota) in their safeguarding approaches at bulk uranium/plutonium handling facilities. Enhancements of environmental sampling techniques used by the IAEA in drawing conclusions concerning the absence of undeclared nuclear materials or activities will soon be able to take advantage of a recent step change improvement in the gathering and analysis of air samples at these facilities. Location specific air monitoring feasibility tests have been performed with excellent results in determining attribute and isotopic composition of chemical elements present in an actual test-bed sample. Isotopic analysis of collected particles from an Aerosol Contaminant Extractor (ACE) collection, was performed with the standard bulk sampling protocol used throughout the IAEA network of analytical laboratories (NWAL). The results yielded bulk isotopic values expected for the operations. Advanced designs of air monitoring instruments such as the ACE may be used in gas centrifuge enrichment plants (GCEP) to detect the production of highly enriched uranium (HEU) or enrichments not declared by a State. Researchers at Savannah River National Laboratory in collaboration with Oak Ridge National Laboratory are developing the next generation of ES equipment for air grab and constant samples that could become an important addition to the international nuclear safeguards inspector's toolkit. Location specific air monitoring to be used to establish a baseline environmental signature of a particular facility employed for comparison of consistencies in declared operations will be described in this paper. Implementation of air monitoring will be contrasted against the use of smear ES

  19. Development and calibration of real-time PCR for quantification of airborne microorganisms in air samples

    NASA Astrophysics Data System (ADS)

    An, Hey Reoun; Mainelis, Gediminas; White, Lori

    This manuscript describes the coupling of bioaerosol collection and the use of real-time PCR (RT-PCR) to quantify the airborne bacteria. The quantity of collected bacteria determined by RT-PCR is compared with conventional quantification techniques, such as culturing, microscopy and airborne microorganism counting by using optical particle counter (OPC). Our data show that an experimental approach used to develop standard curves for use with RT-PCR is critical for accurate sample quantification. Using universal primers we generated 12 different standard curves which were used to quantify model organism Escherichia coli (Migula) Catellani from air samples. Standard curves prepared using a traditional approach, where serially diluted genomic DNA extracted from pure cultured bacteria were used in PCR reaction as a template DNA yielded significant underestimation of sample quantities compared to airborne microorganism concentration as measured by an OPC. The underestimation was especially pronounced when standard curves were built using colony forming units (CFUs). In contrast, the estimate of cell concentration in an air sample by RT-PCR was more accurate (˜60% compared to the airborne microorganism concentration) when the standard curve was built using aerosolized E. coli. The accuracy improved even further (˜100%) when air samples used to build the standard curves were diluted first, then the DNA extracted from each dilution was amplified by the RT-PCR—to mimic the handling of air samples with unknown and possibly low concentration. Therefore, our data show that standard curves used for quantification by RT-PCR needs to be prepared using the same environmental matrix and procedures as handling of the environmental sample in question. Reliance on the standard curves generated with cultured bacterial suspension (a traditional approach) may lead to substantial underestimation of microorganism quantities in environmental samples.

  20. The effect of compressed air foam on the detection of hydrocarbon fuels in fire debris samples.

    PubMed

    Coulson, S A; Morgan-Smith, R K; Noble, D

    2000-01-01

    In 1998/99 the New Zealand Fire Service implemented compressed air foam delivery systems for the suppression of fires in rural areas. This study investigated whether the introduction of the foam to the seat of the fire created any problems in subsequent analyses of fire debris samples. No significant interferences from the foam were found when the samples were analysed by direct headspace using activated carbon strips. The only foam component detected was limonene.

  1. Enclosed chambers for humidity control and sample containment in fiber diffraction

    SciTech Connect

    McDonald, M.; Kendall, A.; Tanaka, M.; Weissman, J.S.; Stubbs, G.

    2008-11-03

    A chamber and stretch frame for making fibers for diffraction is described. The chamber is made from a simple plastic cuvette with silicon nitride windows. It is suitable for maintaining constant humidity during fiber drying and data collection, and allows stretching of the fiber and exposure to magnetic fields during sample preparation. If necessary, it provides primary containment for toxic and infectious biological materials. The chamber has been used in fiber diffraction experiments with filamentous plant viruses and a yeast prion protein, and is shown to produce excellent orientation and to maintain hydration and order at the molecular level.

  2. Enclosed Chambers for Humidity Control And Sample Containment in Fiber Diffraction

    SciTech Connect

    McDonald, M.; Kendall, A.; Tanaka, M.; Weissman, J.S.; Stubbs, G.

    2009-05-26

    A chamber and stretch frame for making fibers for diffraction is described. The chamber is made from a simple plastic cuvette with silicon nitride windows. It is suitable for maintaining constant humidity during fiber drying and data collection, and allows stretching of the fiber and exposure to magnetic fields during sample preparation. If necessary, it provides primary containment for toxic and infectious biological materials. The chamber has been used in fiber diffraction experiments with filamentous plant viruses and a yeast prion protein, and is shown to produce excellent orientation and to maintain hydration and order at the molecular level.

  3. Soyuz 27 Return Samples: Air Quality Aboard the International Space Station: Revised

    NASA Technical Reports Server (NTRS)

    James, John T.

    2012-01-01

    The toxicological assessment of 6 GSCs from the ISS is shown. The average recoveries of the 3 surrogate standards from the grab sample containers were as follows: C-13-acetone, 115%; fluorobenzene, 108%; and chlorobenzene, 93%.

  4. Air and smear sample calculational tool for Fluor Hanford Radiological control

    SciTech Connect

    BAUMANN, B.L.

    2003-07-11

    A spreadsheet calculation tool was developed to automate the calculations performed for determining the concentration of airborne radioactivity and smear counting as outlined in HNF-13536, Section 5.2.7, ''Analyzing Air and Smear Samples''. This document reports on the design and testing of the calculation tool. Radiological Control Technicians (RCTs) will save time and reduce hand written and calculation errors by using an electronic form for documenting and calculating work place air samples. Current expectations are RCTs will perform an air sample and collect the filter or perform a smear for surface contamination. RCTs will then survey the filter for gross alpha and beta/gamma radioactivity and with the gross counts utilize either hand calculation method or a calculator to determine activity on the filter. The electronic form will allow the RCT with a few key strokes to document the individual's name, payroll, gross counts, instrument identifiers; produce an error free record. This productivity gain is realized by the enhanced ability to perform mathematical calculations electronically (reducing errors) and at the same time, documenting the air sample.

  5. Technical assessment of workplace air sampling requirements at tank farm facilities. Revision 2

    SciTech Connect

    Olsen, P.A.; Brown, R.L.

    1995-03-22

    Tank Farm facilities compliance with the workplace air sampling (WPAS) program has been assessed. Requirements bases for determining compliance and recommendations are included. In the current condition all buildings are in compliance with the WPAS program. This document also supersedes WHC-SD-SQA-TA-20012, revision 0.

  6. Modeling and Qualification of a Modified Emission Unit for Radioactive Air Emissions Stack Sampling Compliance

    SciTech Connect

    Barnett, J. Matthew; Yu, Xiao-Ying; Recknagle, Kurtis P.; Glissmeyer, John A.

    2016-01-01

    A planned laboratory space and exhaust system modification to the Pacific Northwest National Laboratory Material Science and Technology Building indicated a new evaluation of the mixing at the air sampling system location would be required for compliance to ANSI/HPS N13.1-2011. The modified exhaust system would add a third fan thereby increasing the overall exhaust rate out the stack thus voiding the previous mixing study. Prior to modifying the radioactive air emissions exhaust system, a three-dimensional computational fluid dynamics computer model was used to evaluate the mixing at the sampling system location. Modeling of the new original three-fan system indicated that not all mixing criteria could be met. A second modeling effort was conducted with the addition of an air blender downstream of the confluence of the three fans which then showed satisfactory mixing results. The final installation included an air blender, and the exhaust system underwent full-scale tests to verify velocity, cyclonic flow, gas, and particulate uniformity. The modeling results and those of the full-scale tests show agreement between each of the evaluated criteria. The use of a computational fluid dynamics code was an effective aid in the design process and allowed the sampling system to remain in its original location while still meeting the requirements for sampling at a well-mixed location.

  7. COMPARISON OF FAST GC/TOFMS WITH METHOD TO-14 FOR ANALYSIS OF AMBIENT AIR SAMPLES

    EPA Science Inventory

    Field studies using portable gas chromatographs (PGC) to analyze volatile organic compounds in ambient air usually include, as reference standard method, the analysis of concurrent, collocated canister samples by EPA Method TO-14. Each laboratory analysis takes about an hour a...

  8. COMPARISON OF MOLD CONCENTRATIONS IN INDOOR AND OUTDOOR AIR SAMPLED SIMULTANEOUSLY AND THEN QUANTIFIED BY MSQPCR

    EPA Science Inventory

    Mold specific quantitative PCR (MSQPCR) was used to measure the concentrations of the 36 mold species in indoor and outdoor air samples that were taken simultaneously for 48 hours in and around 17 homes in Cincinnati, Ohio. The total spore concentrations of 353 per m3...

  9. Development of a wireless air pollution sensor package for aerial-sampling of emissions

    EPA Science Inventory

    A new sensor system for mobile and aerial emission sampling was developed for open area pollutant sources, such as prescribed forest burns. The sensor system, termed “Kolibri”, consists of multiple low-cost air quality sensors measuring CO2, CO, samplers for particulate matter wi...

  10. Potential toxic effects of aircraft de-icers and wastewater samples containing these compounds.

    PubMed

    Mohiley, A; Franzaring, J; Calvo, O C; Fangmeier, A

    2015-09-01

    One of the major problems of airport operation is the impact of pollution caused by runoff waters. Runoff waters at an airport may contain high concentrations of different contaminants resulting from various activities of its operation. High quantities of aircraft de-icing/anti-icing fluids are used annually at airports worldwide. Aircraft de-icers and anti-icers may have negative environmental impacts, but their effects on aquatic organisms are virtually unknown. In order to address this issue, aircraft de-icers, pavement de-icers and wastewater samples were obtained from a regional airport. To evaluate the toxicity of wastewater samples and aircraft de-icing/anti-icing fluids (ADAFs), two bio-tests were performed: the Lemna growth inhibition test according to OECD guideline 221 and the luminescent bacteria test according to ISO guideline 11348-2. In the Lemna growth inhibition test, phytotoxicity was assessed using the endpoints frond number and frond area. The luminescent bacteria test involved the marine bacterium Vibrio fischeri. The estimates of effective concentrations (EC50) values were determined using the free software R and the "drc" library. Aquatic plants and marine bacteria showed a higher sensitivity towards ADAFs than to wastewater samples. Experiments showed that aircraft de-icing/anti-icing fluids and wastewater samples were relatively more toxic towards Lemna gibba L. in comparison to V. fischeri.

  11. Ten-year air sample analysis of Aspergillus prevalence in a university hospital.

    PubMed

    Falvey, D G; Streifel, A J

    2007-09-01

    Airborne fungal samples were collected on a monthly basis for 10 years, from 1995 to 2005, at a tertiary university hospital. Paired samples were cultured at 25 and 37 degrees C. Data were interpreted according to the air filtration systems serving each location. Samples cultured at 37 degrees C from the patient care areas had a mean recovery of 18% of the mean recovery from outdoor air (22 versus 122cfu/m(3)). Recovery of Aspergillus spp. at 37 degrees C in the high-efficiency particulate air (HEPA)-filtered locations was positive for Aspergillus spp. approximately one-third of the time; the rest of the patient care areas were positive half of the time and the outdoor samples were positive 95% of the time. We found 48 sporadic bursts at 37 degrees C which produced counts >3 SD above the mean. Hospital-acquired infection was related to high recovery of Aspergillus fumigatus on at least one occasion. We have found it impossible, without implementing impractical measures, to provide an environment completely devoid of Aspergillus spp. We conclude that routine air sampling is not an effective means of predicting hospital-acquired infections. However, a transient spike, or burst, may be useful in identifying an in-house source of contamination and may be used to consider additional interventional treatments for patients at risk. Emphasis should be placed on maintaining high-efficiency filtration of the outside air and on ensuring that other environmental control methods are used to prevent dissemination of environmental opportunistic fungal spores.

  12. Results of Self-Absorption Study on the Versapor 3000 Filters for Radioactive Particulate Air Sampling

    SciTech Connect

    Barnett, J. Matthew

    2008-08-22

    Since the mid-1980s the Pacific Northwest National Laboratory (PNNL) has used a value of 0.85 as a correction factor for the self absorption of activity of particulate radioactive air samples. More recently, an effort was made to evaluate the current particulate radioactive air sample filters (Versapor® 3000) used at PNNL for self absorption effects. There were two methods used in the study, 1) to compare the radioactivity concentration by direct gas-flow proportional counting of the filter to the results obtained after acid digestion of the filter and counting again by gas-flow proportional detection and 2) to evaluate sample filters by high resolution visual/infrared microscopy to determine the depth of material loading on or in the filter fiber material. Sixty samples were selected from the archive for acid digestion in the first method and about 30 samples were selected for high resolution visual/infrared microscopy. Mass loading effects were also considered. From the sample filter analysis, large error is associated with the average self absorption factor, however, when the data is compared directly one-to-one, statistically, there appears to be good correlation between the two analytical methods. The mass loading of filters evaluated was <0.2 mg cm-2 and was also compared against other published results. The microscopy analysis shows the sample material remains on the top of the filter paper and does not imbed into the filter media. Results of the microscopy evaluation lead to the conclusion that there is not a mechanism for significant self absorption. The overall conclusion is that self-absorption is not a significant factor in the analysis of filters used at PNNL for radioactive air stack sampling of radionuclide particulates and that an applied correction factor is conservative in determining overall sample activity. A new self absorption factor of 1.0 is recommended.

  13. Air-lift reactor system for the treatment of waste-gas-containing monochlorobenzene.

    PubMed

    Joshi, Pradnya R; Deshmukh, Sharvari C; Morone, Amruta P; Kanade, Gajanan; Pandey, R A

    2013-01-01

    An air-lift bioreactor (ALR) system, applied for the treatment of waste-gas-containing monochlorobenzene (MCB) was seeded with pure culture of Acinetobacter calcoaceticus, isolated from soil as a starter seed. It was found that MCB was biologically converted to chloride as chloride was mineralized in the ALR. After the built up of the biomass in the ALR, the reactor parameters which have major influence on the removal efficiency and elimination capacity were studied using response surface methodology. The data generated by running the reactor for 150 days at varying conditions were fed to the model with a target to obtain the removal efficiency above 95% and the elimination capacity greater than 60%. The data analysis indicated that inlet loading was the major parameter affecting the elimination capacity and removal efficiency of >95%. The reactor when operated at optimized conditions resulted in enhanced performance of the reactor.

  14. Mathematical estimation of the level of microbial contamination on spacecraft surfaces by volumetric air sampling

    NASA Technical Reports Server (NTRS)

    Oxborrow, G. S.; Roark, A. L.; Fields, N. D.; Puleo, J. R.

    1974-01-01

    Microbiological sampling methods presently used for enumeration of microorganisms on spacecraft surfaces require contact with easily damaged components. Estimation of viable particles on surfaces using air sampling methods in conjunction with a mathematical model would be desirable. Parameters necessary for the mathematical model are the effect of angled surfaces on viable particle collection and the number of viable cells per viable particle. Deposition of viable particles on angled surfaces closely followed a cosine function, and the number of viable cells per viable particle was consistent with a Poisson distribution. Other parameters considered by the mathematical model included deposition rate and fractional removal per unit time. A close nonlinear correlation between volumetric air sampling and airborne fallout on surfaces was established with all fallout data points falling within the 95% confidence limits as determined by the mathematical model.

  15. A survey of results for passive air and water sampling via semipermeable membrane devices

    SciTech Connect

    Prest, H.F.; Jacobson, L.; Hodgins, M.; Huckins, J.N.; Petty, J.D.; Richardson, B.; Wilson, M.; Martin, M.

    1994-12-31

    Passive sampling techniques have progressed and are providing new possibilities for measuring trace contaminants in environmental compartments. One such device, the semipermeable membrane device (SPMD) developed by Huckins, et al in Columbia, MO. is especially promising. The authors present an overview of results for sampling in air and water with semipermeable membrane devices (SPMDS) for organochlorines and polynuclear aromatic hydrocarbons (PAHs) and comment on possible future applications and potential. Differences in organohalogen profiles for SPMDs and green-lipped mussels deployed along transacts of Corio Bay, Australia show marked differences in sequestering ``windows``. An illustration of the application of SPMDs to the measurement of the half-life of chemicals is presented using PAH data from SPMD deployments in an irrigation canal in New Mexico. Results for simultaneous sampling of water and coastal air in Northern California illustrate the promise of SPMDs as global monitors.

  16. Irradiation corrosion of waste package container materials in air/steam environment

    SciTech Connect

    Anantatmula, R.P.; Colburn, R.P.

    1991-11-01

    A set of corrosion tests of the candidate waste container materials for the Basalt Waste Isolation Project (BWIP) was conducted in a moist air environment simulating the repository preclosure condition. The tests were performed over a four-month period with air, saturated with moisture at 50{degree}C, passing through test chambers holding specimens at 150{degree}C and 250{degree}C. The test materials included A27 cast carbon steel, A387 ferritic steel, oxygen-free copper and cupronickel 90-10. Each material was tested both with and without basalt/bentonite packing material adjacent to the specimens. For each combination of material, temperature and packing condition, tests were conducted at 10,000 R/hr and 100 R/hr radiation levels. All four materials tested at 250{degree}C showed corrosion rates as much as an order of magnitude higher in the high radiation field when compared with similar tests without irradiation. Typically, the corrosion rates were lower at the lower dose rates, but were significantly higher at 100 R/hr compared to the case without radiation. At 150{degree}C only pure copper showed enhanced corrosion due to gamma radiation. The presence of packing material adjacent to the specimens had no consistent effect on corrosion rate at either temperature.

  17. Survey of RFID and Its Application to International Ocean/Air Container Tracking

    NASA Astrophysics Data System (ADS)

    Katayama, Minoru; Nakada, Hiroshi; Hayashi, Hitoshi; Shimizu, Masashi

    “Internet of Things” (IoT) requires information to be collected from “anything”, “anytime”, and “anywhere”. In order to achieve this, wireless devices are required that have (1) automatic data acquisition capability, (2) small size, (3) long life, and (4) long range communication capability. One way to meet these requirements is to adopt active Radio Frequency Identification (RFID) systems. Active RFID is more advantageous than passive RFID and enables higher data reading performance over longer distances. This paper surveys active RFID systems, the services they currently promise to provide, technical problems common to these services, and the direction in which research should head in the future. It also reports the results of EPCglobal (EPC: Electronic Product Code) pilot tests conducted on global logistics for tracking ocean/air container transportation using active RFID systems for which we developed several new types of active RFID tags. The test results confirm that our active RFID tags have sufficient capability and low power consumption to well support ocean/air transportation and logistics service.

  18. A stringent comparison of sampling and analysis methods for VOCs in ambient air

    SciTech Connect

    Daughtrey, E.H. Jr.; Oliver, K.D.; Adams, J.R.; Kronmiller, K.G.; Lonneman, W.A.; McClenny, W.A.; Colon, M.

    1999-07-01

    A carefully designed study was conducted during the summer of 1998 to simultaneously collect samples of ambient air by canisters and compare the analysis results to direct sorbent preconcentration results taken at the time of sample collection. A total of 32 1-h sample sets were taken, each composed of a real-time sample analyzed by an autoGC/MS XonTech 930/Varian Saturn 2000 system, and SUMMA and Silco canisters. Hourly total non-methane organic carbon (TNMOC), ozone, and meteorological measurements were also made. Each of the canisters was analyzed on the autoGC/MS system for a target list of 108 VOCs and on a manual cryosampling GC/FID system. Comparisons are made between the collection and analysis methods. Because of the low sample loading (150--250 ppbC TNMOC), these comparisons are a stringent test of sample collection and analysis capabilities.

  19. Whole Air Sampling During NASA's March-April 1999 Pacific Exploratory Expedition (PEM-Tropics B)

    NASA Technical Reports Server (NTRS)

    Blake, Donald R.

    2001-01-01

    University of California, Irvine (UCI) collected more than 4500 samples whole air samples collected over the remote Pacific Ocean during NASA's Global Tropospheric Experiment (GTE) Pacific Exploratory Mission-Tropics B (PEM-Tropics B) in March and early April 1999. Approximately 140 samples during a typical 8-hour DC-8 flight, and 120 canisters for each 8-hour flight aboard the P-3B. These samples were obtained roughly every 3-7 min during horizontal flight legs and 1-3 min during vertical legs. The filled canisters were analyzed in the laboratory at UCI within ten days of collection. The mixing ratios of 58 trace gases comprising hydrocarbons, halocarbons, alkyl nitrates and DMS were reported (and archived) for each sample. Two identical analytical systems sharing the same standards were operated simultaneously around the clock to improve canister turn-around time and to keep our measurement precision optimal. This report presents a summary of the results for sample collected.

  20. Volatile organic components of air samples collected from Vertical Launch Missile capsules. Summary report

    SciTech Connect

    Tappan, D.V.; Knight, D.R.; Heyder, E.; Weathersby, P.K.

    1988-09-27

    Gas chromatographic/mass spectroscopic analyses are presented for the volatile organic components found in air samples collected from the inboard vents from Vertical Launch System (VLS) missile capsules aboard a 688 class submarine. Similar analyses were also conducted for a sample of the ship's high pressure air used to fill the missile tubes. A wide variety of organics was detected in the air from the missile capsules; and while no unique components have yet been identified, a significant contribution has been shown to be made by pressure-ventilation of the VLS capsules into the submarine atmosphere which is already heavily laden with volatile organic compounds. The most apparent conclusion from these preliminary analyses is that the mixtures of organic components in the air within VLS missile capsules vary greatly from capsule to capsule (and probably from time to time). Many such samples need to be investigated to provide sufficient information to judge the seriousness of the possibility of venting toxic components into the submarine atmosphere during the maintenance or firing of VLS missiles.

  1. Quantitative Passive Diffusive Sampling for Assessing Soil Vapor Intrusion to Indoor Air

    DTIC Science & Technology

    2012-03-28

    4/11/2012 1 Quantitative Passive Diffusive Sampling for Assessing Soil Vapor Intrusion to Indoor Air Todd McAlary and Hester Groenevelt, Geosyntec... Intrusion to Indoor Air 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK...10-6 risk (ppb) Vapour pressure (atm) Water solubility (g/l) 1,1,1-Trichloroethane 110 400 0.16 1.33 1,2,4-Trimethylbenzene

  2. Conservation of phage reference materials and water samples containing bacteriophages of enteric bacteria.

    PubMed

    Mendez, J; Jofre, J; Lucena, F; Contreras, N; Mooijman, K; Araujo, R

    2002-12-01

    The survival was determined in different conservation conditions of: somatic coliphages, F-specific RNA bacteriophages and phages infecting Bacteroides fragilis proposed as model micro-organisms for water quality control. Titres of phages of all groups either in pure culture phage suspensions or in naturally occurring phage suspensions were stable at (-70+/-10) degrees C and at (-20+/-5) degrees C when protected with glycerol. Moreover, phage analysis of stored suspensions demonstrated that their numbers were homogeneous, both between vials and within vials, and consequently they can be used as reference materials. Furthermore, changes in the storage temperature of the vials cause unpredictable changes in the numbers of bacteriophages. Consequently, phage reference materials and samples containing a quantitative number of phages must be maintained and dispatched at a constant temperature. Consequently, the results indicate that bacteriophages should be packed in dry ice during transport and storage. Finally, the number of phages in water samples stored at (5+/-3) degrees C in the dark does not decrease significantly during the first 72 h of storage. In addition, phage concentrates from natural samples obtained by adsorption-elution to cellulose nitrate filters and mixed with 10% glycerol were stable at least for 2 months at (-70+/-10) degrees C and at (-20+/-5) degrees C.

  3. Increasing concentrations of dichloromethane, CH2Cl2, inferred from CARIBIC air samples collected 1998-2012

    NASA Astrophysics Data System (ADS)

    Leedham Elvidge, E. C.; Oram, D. E.; Laube, J. C.; Baker, A. K.; Montzka, S. A.; Humphrey, S.; O'Sullivan, D. A.; Brenninkmeijer, C. A. M.

    2015-02-01

    Atmospheric concentrations of dichloromethane, CH2Cl2, a regulated toxic air pollutant and minor contributor to stratospheric ozone depletion, were reported to have peaked around 1990 and to be declining in the early part of the 21st century. Recent observations suggest this trend has reversed and that CH2Cl2 is once again increasing in the atmosphere. Despite the importance of ongoing monitoring and reporting of atmospheric CH2Cl2, no time series has been discussed in detail since 2006. The CARIBIC project (Civil Aircraft for the Regular Investigation of the atmosphere Based on an Instrument Container) has analysed the halocarbon content of whole-air samples collected at altitudes of between ~ 10-12 km via a custom-built container installed on commercial passenger aircraft since 1998, providing a long-term record of CH2Cl2 observations. In this paper we present this unique CH2Cl2 time series, discussing key flight routes which have been used at various times over the past 15 years. Between 1998 and 2012 increases were seen in all northern hemispheric regions and at different altitudes, ranging from ~ 7-10 ppt in background air to ~ 13-15 ppt in regions with stronger emissions (equating to a 38-69% increase). Of particular interest is the rising importance of India as a source of atmospheric CH2Cl2: based on CARIBIC data we provide regional emission estimates for the Indian subcontinent and show that regional emissions have increased from 3-14 Gg yr-1 (1998-2000) to 16-25 Gg yr-1 (2008). Potential causes of the increasing atmospheric burden of CH2Cl2 are discussed. One possible source is the increased use of CH2Cl2 as a feedstock for the production of HFC-32, a chemical used predominantly as a replacement for ozone-depleting substances in a variety of applications including air conditioners and refrigeration.

  4. Increasing concentrations of dichloromethane, CH2Cl2, inferred from CARIBIC air samples collected 1998-2012

    NASA Astrophysics Data System (ADS)

    Leedham Elvidge, E. C.; Oram, D. E.; Laube, J. C.; Baker, A. K.; Montzka, S. A.; Humphrey, S.; O'Sullivan, D. A.; Brenninkmeijer, C. A. M.

    2014-08-01

    Dichloromethane, CH2Cl2, is a short-lived chlorocarbon of predominantly anthropogenic origin. Increasing industrial usage and associated emissions resulted in an increasing atmospheric burden throughout the 1900s. Atmospheric abundance peaked around 1990 and was followed by a decline in the early part of the 21st century. Despite the importance of ongoing monitoring and reporting of atmospheric CH2Cl2 (it is a regulated toxic air pollutant and a contributor to stratospheric ozone depletion) no time series has been discussed in detail since 2006. The CARIBIC project (Civil Aircraft for the Regular Investigation of the atmosphere Based on an Instrument Container) has analysed the halocarbon content of whole air samples collected at altitudes of between ~10-12 km via a custom-built container installed on commercial passenger aircraft since 1998, providing a long-term record of CH2Cl2 observations. In this paper we present this unique CH2Cl2 time series, discussing key flight routes which have been traversed at various times over the past 15 years. Between 1998 and 2012 increases were seen in all northern hemispheric regions and at different altitudes, ranging from ~7-9 ppt in background air to ~12-15 ppt in regions with stronger emissions (equating to a 38-69% increase). Of particular interest is the rising importance of India as a source of atmospheric CH2Cl2: based on CARIBIC data we provide regional emission estimates for the Indian subcontinent and show that regional emissions have increased from 3-15 Gg yr-1 (1998-2000) to 16-25 Gg yr-1 (2008). Potential causes of the increasing atmospheric burden of CH2Cl2 are discussed. One possible source is the increased use of CH2Cl2 as a feedstock for the production of HFC-32, a chemical used predominantly as a replacement for ozone-depleting substances in a variety of applications including air conditioners and refrigeration.

  5. Elastic airtight container for the compaction of air-sensitive materials

    NASA Astrophysics Data System (ADS)

    Shoulders, W. Taylor; Locke, Richard; Gaume, Romain M.

    2016-06-01

    We report on the design and fabrication of a simple and versatile elastic canister for the compaction and hot-pressing of air-sensitive materials. This device consists of a heated double-ended floating die assembly, enclosed in a compressible stainless steel bellows that allows the action of an external hydraulic press in a uniaxial motion. The enclosure is fitted with vacuum, gas, and electrical feedthroughs to allow for atmosphere control, heating, and in situ process monitoring. The overall chamber is compact enough to be portable and transferrable into and out of a standard laboratory glovebox, thus eliminating the problem of exposing samples to ambient atmosphere during loading and unloading. Our design has been tested up to 600 °C and 7500 kg-force applied load, conditions within which transparent ceramics of anhydrous halides can be produced.

  6. Nonradioactive Air Emissions Notice of Construction (NOC) Application for the Central Waste Complex (CSC) for Storage of Vented Waste Containers

    SciTech Connect

    KAMBERG, L.D.

    2000-04-01

    This Notice of Construction (NOC) application is submitted for the storage and management of waste containers at the Central Waste Complex (CWC) stationary source. The CWC stationary source consists of multiple sources of diffuse and fugitive emissions, as described herein. This NOC is submitted in accordance with the requirements of Washington Administrative Code (WAC) 173-400-110 (criteria pollutants) and 173-460-040 (toxic air pollutants), and pursuant to guidance provided by the Washington State Department of Ecology (Ecology). Transuranic (TRU) mixed waste containers at CWC are vented to preclude the build up of hydrogen produced as a result of radionuclide decay, not as safety pressure releases. The following activities are conducted within the CWC stationary source: Storage and inspection; Transfer and staging; Packaging; Treatment; and Sampling. This NOC application is intended to cover all existing storage structures within the current CWC treatment, storage, and/or disposal (TSD) boundary, as well as any storage structures, including waste storage pads and staging areas, that might be constructed in the future within the existing CWC boundary.

  7. Determination of air-loop volume and radon partition coefficient for measuring radon in water sample.

    PubMed

    Lee, Kil Yong; Burnett, William C

    A simple method for the direct determination of the air-loop volume in a RAD7 system as well as the radon partition coefficient was developed allowing for an accurate measurement of the radon activity in any type of water. The air-loop volume may be measured directly using an external radon source and an empty bottle with a precisely measured volume. The partition coefficient and activity of radon in the water sample may then be determined via the RAD7 using the determined air-loop volume. Activity ratios instead of absolute activities were used to measure the air-loop volume and the radon partition coefficient. In order to verify this approach, we measured the radon partition coefficient in deionized water in the temperature range of 10-30 °C and compared the values to those calculated from the well-known Weigel equation. The results were within 5 % variance throughout the temperature range. We also applied the approach for measurement of the radon partition coefficient in synthetic saline water (0-75 ppt salinity) as well as tap water. The radon activity of the tap water sample was determined by this method as well as the standard RAD-H2O and BigBottle RAD-H2O. The results have shown good agreement between this method and the standard methods.

  8. Investigation of Buried Pesticide Containers (Step 2), Stewart Air National Guard Base, Newburgh, New York.

    DTIC Science & Technology

    1986-05-30

    34. Analyses of samples from that test pit indicated the presence of high concentrations of DDT in an apparent oil carrier. Because the burial zone appeared...on the north, south and west margins of the newly defined target area. These test pits confirmed the presence of buried containers of DDT in an oil ...11 of 37. N q0 0 C 96 . * U U. I x 0I . flD ..1 ~ 16 V ,- .C " = = _ ° _ - Of Cr c 6. 6 6Z -0 -- Z 10. 2 .. ’’ I~~Al Q ~.U 40 41 41 4,t%!----- I

  9. Air Sampling of Polychlorinated Dibenzodioxins, Polychlorinated Dibenzofurans, and Polychlorinated Biphenyls Arnold AFS, Tennessee.

    DTIC Science & Technology

    1987-01-01

    DIBENZOFURANS, AND POLYCHLORINATED BIPHENYLS ARNOLD AFS TN ISAAC ATKINS, JR., CAPTAIN, USAF, BSC January 1987 D I ~ELECTE FINAL REPORT 0Wfl D LU...NO 11. TITLE (Include Security ClassificatiOtl) Air Sampling of Polychlorinated Dibenzodioxins, Polychlorinated Dibenzofurans, and Polychlorinated ... Biphenyls at Arnold AFS TN (U) 12. PERSONAL AUTHOR(S) Captaiq Isaac Atkins, Jr. 13a. TYP OF REPORT 13b. TIME COVERED 14. DATE OF REPORT (Year, Month

  10. Measurement of the Tracer Gradient and Sampling System Bias of the Hot Fuel Examination Facility Stack Air Monitoring System

    SciTech Connect

    Glissmeyer, John A.; Flaherty, Julia E.

    2011-07-20

    This report describes tracer gas uniformity and bias measurements made in the exhaust air discharge of the Hot Fuel Examination Facility at Idaho National Laboratory. The measurements were a follow-up on earlier measurements which indicated a lack of mixing of the two ventilation streams being discharged via a common stack. The lack of mixing is detrimental to the accuracy of air emission measurements. The lack of mixing was confirmed in these new measurements. The air sampling probe was found to be out of alignment and that was corrected. The suspected sampling bias in the air sample stream was disproved.

  11. Interconversion of chromium species during air sampling: effects of O3, NO2, SO2, particle matrices, temperature, and humidity.

    PubMed

    Huang, Lihui; Fan, Zhihua Tina; Yu, Chang Ho; Hopke, Philip K; Lioy, Paul J; Buckley, Brian T; Lin, Lin; Ma, Yingjun

    2013-05-07

    The interconversion between Cr(VI), a pulmonary carcinogen, and Cr(III), an essential human nutrient, poses challenges to the measurement of Cr(VI) in airborne particles. Chamber and field tests were conducted to identify the factors affecting Cr(VI)-Cr(III) interconversion in the basic filter medium under typical sampling conditions. In the chamber tests, isotopically enriched (53)Cr(VI) and (50)Cr(III) were spiked on diesel particulate matter (DPM) and secondary organic aerosol (SOA) that were precollected on a basic MCE filter. The filter samples were then exposed to clean air or the air containing SO2 (50 and 160 ppb), 100 ppb O3, or 150 ppb NO2 for 24 h at 16.7 LPM flow rate at designated temperature (20 and 31 °C) and RH (40% and 70%) conditions. Exposure to 160 ppb SO2 had the greatest effect on (53)Cr(VI) reduction, with (53)Cr(VI) recovery of 31.7 ± 15.8% (DPM) and 42.0 ± 7.9% (SOA). DPM and SOA matrix induced (53)Cr(VI) reduction when exposed to clean air while reactive oxygen species in SOA could promote (50)Cr(III) oxidation. Deliquescence when RH increased from 40% to 70% led to conversion of Cr(III) in SOA, whereas oxidized organics in DPM and SOA enhanced hygroscopicity and thus facilitated Cr(VI) reduction. Field tests showed seasonal variation of Cr(VI)-Cr(III) interconversion during sampling. Correction of the interconversion using USEPA method 6800 is recommended to improve accuracy of ambient Cr(VI) measurements.

  12. Isotopic air sampling in a tallgrass prairie to partition net ecosystem CO2 exchange

    NASA Astrophysics Data System (ADS)

    Lai, Chun-Ta; Schauer, Andrew J.; Owensby, Clenton; Ham, Jay M.; Ehleringer, James R.

    2003-09-01

    Stable isotope ratios of various ecosystem components and net ecosystem exchange (NEE) CO2 fluxes were measured in a C3-C4 mixture tallgrass prairie near Manhattan, Kansas. The July 2002 study period was chosen because of contrasting soil moisture contents, which allowed us to address the effects of drought on photosynthetic CO2 uptake and isotopic discrimination. Significantly higher NEE fluxes were observed for both daytime uptake and nighttime respiration during well-watered conditions when compared to a drought period. Given these differences, we investigated two carbon-flux partitioning questions: (1) What proportions of NEE were contributed by C3 versus C4 species? (2) What proportions of NEE fluxes resulted from canopy assimilation versus ecosystem respiration? To evaluate these questions, air samples were collected every 2 hours during daytime for 3 consecutive days at the same height as the eddy covariance system. These air samples were analyzed for both carbon isotope ratios and CO2 concentrations to establish an empirical relationship for isoflux calculations. An automated air sampling system was used to collect nighttime air samples to estimate the carbon isotope ratios of ecosystem respiration (δR) at weekly intervals for the entire growing season. Models of C3 and C4 photosynthesis were employed to estimate bulk canopy intercellular CO2 concentration in order to calculate photosynthetic discrimination against 13C. Our isotope/NEE results showed that for this grassland, C4 vegetation contributed ˜80% of the NEE fluxes during the drought period and later ˜100% of the NEE fluxes in response to an impulse of intense precipitation. For the entire growing season, the C4 contribution ranged from ˜68% early in the spring to nearly 100% in the late summer. Using an isotopic approach, the calculated partitioned respiratory fluxes were slightly greater than chamber-measured estimates during midday under well-watered conditions. In addition, time series

  13. Microbial Air and Surface Monitoring Results from International Space Station Samples

    NASA Technical Reports Server (NTRS)

    Ott, C. Mark; Bruce, Rebekah J.; Castro, Victoria A.; Novikova, Natalia D.; Pierson, D. L.

    2005-01-01

    Over the course of long-duration spaceflight, spacecraft develop a microbial ecology that directly interacts with the crew of the vehicle. While most microorganisms are harmless or beneficial to the inhabitants of the vehicle, the presence of medically significant organisms appearing in this semi-closed environment could adversely affect crew health and performance. The risk of exposure of the crew to medically significant organisms during a mission is estimated using information gathered during nominal and contingency environmental monitoring. Analysis of the air and surface microbiota in the habitable compartments of the International Space Station (ISS) over the last four years indicate a high presence of Staphylococcus species reflecting the human inhabitants of the vehicle. Generally, air and surface microbial concentrations are below system design specifications, suggesting a lower risk of contact infection or biodegradation. An evaluation of sample frequency indicates a decrease in the identification of new species, suggesting a lower potential for unknown microorganisms to be identified. However, the opportunistic pathogen, Staphylococcus aureus, has been identified in 3 of the last 5 air samples and 5 of the last 9 surface samples. In addition, 47% of the coagulase negative Staphylococcus species that were isolated from the crew, ISS, and its hardware were found to be methicillin resistance. In combination, these observations suggest the potential of methicillin resistant infectious agents over time.

  14. Technical assessment of workplace air sampling requirements at tank farm facilities. Revision 1

    SciTech Connect

    Olsen, P.A.

    1994-09-21

    WHC-CM-1-6 is the primary guidance for radiological control at Westinghouse Hanford Company (WHC). It was written to implement DOE N 5480.6 ``US Department of Energy Radiological Control Manual`` as it applies to programs at Hanford which are now overseen by WHC. As such, it complies with Title 10, Part 835 of the Code of Federal Regulations. In addition to WHC-CM-1-6, there is HSRCM-1, the ``Hanford Site Radiological Control Manual`` and several Department of Energy (DOE) Orders, national consensus standards, and reports that provide criteria, standards, and requirements for workplace air sampling programs. This document provides a summary of these, as they apply to WHC facility workplace air sampling programs. This document also provides an evaluation of the compliance of Tank Farms` workplace air sampling program to the criteria, standards, and requirements and documents compliance with the requirements where appropriate. Where necessary, it also indicates changes needed to bring specific locations into compliance.

  15. The use of Whatman-41 filters for high volume air sampling

    NASA Technical Reports Server (NTRS)

    Neustadter, H. E.; Sidik, S. M.; King, R. B.; Fordyce, J. S.; Burr, J. C.

    1975-01-01

    The feasibility of using W41 filter media on a routine TSP high-volume monitoring network was determined by comparison with glass fiber (GF) filtering. Results indicate that suspended particulate samples from GF filters averaged slightly, but not significantly, higher than those from Whatman-41 filters. Some extra handling procedures were required to avoid errors due to the hygroscopic nature of W41 filters; these added procedures are not overly burdensome, however, and they allow the performance of analytical work, thus extending the capabilities of high-volume sampling. It was demonstrated that W41 filters are practical for air quality monitoring and elemental analysis in environments similar to Cleveland's.

  16. Sampling and analysis of trace-organic constituents in ambient and workplace air at coal-conversion facilities

    SciTech Connect

    Flotard, R D

    1980-07-01

    A review of the recent literature reveals that current sampling procedures involve the use of glass fiber filters for particulate-sorbed organics and sorbent resins such as Tenax GC and XAD-2 for vapor-phase organics. Ultra trace-organic analysis of air pollutants or particulates may require the collection of a large (1000 to 3000 m/sup 3/) sample by a high volume air sampler. Personal air sampling requires a smaller (approx. = 0.5 m/sup 3/) and a portable collection apparatus. Trapped organic chemicals are recovered by solvent extraction or thermal desorption of the collector. Recovered organics are separated by using liquid chromatography or gas chromatography and are identified by ultraviolet or fluorescence spectroscopy, gas chromatography, or mass spectrometry. For quantification, standards are added to the air stream during sampling or to the filter or resin following sampling. Analysis of the requirement for air sampling in and around coal conversion plants, coupled with the findings of the literature review, indicates that a combined particulate-filter and solvent-extractable-resin sampling unit should be used to collect both particulate-sorbed organics and vapor-phase organics from workplace or ambient plant air. Such a sampler was developed for stationary, moderate-to-high-volume air sampling. Descriptions of the sampler are provided together with sampling efficiency information and recommendations for a sampling procedure.

  17. A new analysis system for whole air sampling: description and results from 2013 SENEX

    NASA Astrophysics Data System (ADS)

    Lerner, B. M.; Gilman, J.; Dumas, M.; Hughes, D.; Jaksich, A.; Hatch, C. D.; Graus, M.; Warneke, C.; Apel, E. C.; Hornbrook, R. S.; Holloway, J. S.; De Gouw, J. A.

    2014-12-01

    Accurate measurement of volatile organic compounds (VOCs) in the troposphere is critical for the understanding of emissions and physical and chemical processes that can impact both air quality and climate. Airborne VOC measurements have proven especially challenging due to the requirement of both high sensitivity (pptv) and short sample collection times (≤15 s) to maximize spatial resolution and sampling frequency for targeted plume analysis. The use of stainless steel canisters to collect whole air samples (WAS) for post-flight analysis has been pioneered by the groups of D. Blake and E. Atlas [Blake et al., 1992; Atlas et al., 1993]. For the 2013 Southeast Nexus Study (SENEX), the NOAA ESRL CSD laboratory undertook WAS measurements for the first time. This required the construction of three new, highly-automated, and field-portable instruments designed to sample, analyze, and clean the canisters for re-use. Analysis was performed with a new custom-built gas chromatograph-mass spectrometer system. The instrument pre-concentrates analyte cryostatically into two parallel traps by means of a Stirling engine, a novel technique which obviates the need for liquid nitrogen to reach trapping temperatures of -175C. Here we present an evaluation of the retrieval of target VOC species from WAS canisters. We discuss the effects of humidity and sample age on the analyte, particularly upon C8+ alkane and aromatic species and biogenic species. Finally, we present results from several research flights during SENEX that targeted emissions from oil/natural gas production.

  18. Air

    MedlinePlus

    ... do to protect yourself from dirty air . Indoor air pollution and outdoor air pollution Air can be polluted indoors and it can ... this chart to see what things cause indoor air pollution and what things cause outdoor air pollution! Indoor ...

  19. Airborne Detection and Quantification of Swine Influenza A Virus in Air Samples Collected Inside, Outside and Downwind from Swine Barns

    PubMed Central

    Corzo, Cesar A.; Culhane, Marie; Dee, Scott; Morrison, Robert B.; Torremorell, Montserrat

    2013-01-01

    Airborne transmission of influenza A virus (IAV) in swine is speculated to be an important route of virus dissemination, but data are scarce. This study attempted to detect and quantify airborne IAV by virus isolation and RRT-PCR in air samples collected under field conditions. This was accomplished by collecting air samples from four acutely infected pig farms and locating air samplers inside the barns, at the external exhaust fans and downwind from the farms at distances up to 2.1 km. IAV was detected in air samples collected in 3 out of 4 farms included in the study. Isolation of IAV was possible from air samples collected inside the barn at two of the farms and in one farm from the exhausted air. Between 13% and 100% of samples collected inside the barns tested RRT-PCR positive with an average viral load of 3.20E+05 IAV RNA copies/m3 of air. Percentage of exhaust positive air samples also ranged between 13% and 100% with an average viral load of 1.79E+04 RNA copies/m3 of air. Influenza virus RNA was detected in air samples collected between 1.5 and 2.1 Km away from the farms with viral levels significantly lower at 4.65E+03 RNA copies/m3. H1N1, H1N2 and H3N2 subtypes were detected in the air samples and the hemagglutinin gene sequences identified in the swine samples matched those in aerosols providing evidence that the viruses detected in the aerosols originated from the pigs in the farms under study. Overall our results indicate that pigs can be a source of IAV infectious aerosols and that these aerosols can be exhausted from pig barns and be transported downwind. The results from this study provide evidence of the risk of aerosol transmission in pigs under field conditions. PMID:23951164

  20. Effects of Subsurface Sampling & Processing on Martian Simulant Containing Varying Quantities of Water

    NASA Technical Reports Server (NTRS)

    Menard, J.; Sangillo, J.; Savain, A.; McNamara, K. M.

    2004-01-01

    The presence of water-ice in the Martian subsurface is a subject of much debate and excited speculation. Recent results from the gammaray spectrometer (GRS) on board NASA's Mars Odyssey spacecraft indicate the presence of large amounts of hydrogen in regions of predicted ice stability. The combination of chemistry, low gravitational field (3.71 m/s(exp 2)) and a surface pressure of about 6.36 mbar at the mean radius, place limits on the stability of H2O on the surface, however, results from the GRS indicate that the hydrogen rich phase may be present at a depth as shallow as one meter in some locations on Mars. The potential for water on Mars leads directly to the speculation that life may once have existed there, since liquid water is the unifying factor for environments known to support life on Earth. Lubricant-free drilling has been considered as a means of obtaining water-rich subsurface samples on Mars, and two recent white papers sponsored by the Mars Program have attempted to identify the problems associated with this goal. The two major issues identified were: the engineering challenges of drilling into a water-soil mixture where phase changes may occur; and the potential to compromise the integrity of in-situ scientific analysis due to contamination, volatilization, and mineralogical or chemical changes as a result of processing. This study is a first attempt to simulate lubricantfree drilling into JSC Mars-1 simulant containing up to 50% water by weight. The goal is to address the following: 1) Does sample processing cause reactions or changes in mineralogy which will compromise the interpretation of scientific measurements conducted on the surface? 2) Does the presence of water-ice in the sample complicate (1)? 3) Do lubricant-free drilling and processing leave trace contaminants which may compromise our understanding of sample composition? 4) How does the torque/power required for drilling change as a function of water content and does this lead to

  1. Sampling artifacts in active air sampling of semivolatile organic contaminants: Comparing theoretical and measured artifacts and evaluating implications for monitoring networks.

    PubMed

    Melymuk, Lisa; Bohlin-Nizzetto, Pernilla; Prokeš, Roman; Kukučka, Petr; Klánová, Jana

    2016-10-01

    The effects of sampling artifacts are often not fully considered in the design of air monitoring with active air samplers. Semivolatile organic contaminants (SVOCs) are particularly vulnerable to a range of sampling artifacts because of their wide range of gas-particle partitioning and degradation rates, and these can lead to erroneous measurements of air concentrations and a lack of comparability between sites with different environmental and sampling conditions. This study used specially adapted filter-sorbent sampling trains in three types of active air samplers to investigate breakthrough of SVOCs, and the possibility of other sampling artifacts. Breakthrough volumes were experimentally determined for a range of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs) and polybrominated diphenyl ethers (PBDEs) in sampling volumes from 300 to 10,000 m(3), and sampling durations of 1-7 days. In parallel, breakthrough was estimated based on theoretical sorbent-vapor pressure relationships. The comparison of measured and theoretical determinations of breakthrough demonstrated good agreement between experimental and estimated breakthrough volumes, and showed that theoretical breakthrough estimates should be used when developing air monitoring protocols. Significant breakthrough in active air samplers occurred for compounds with vapor pressure >0.5 Pa at volumes <700 m(3). Sample volumes between 700 and 10,000 m(3) may lead to breakthrough for compounds with vapor pressures between 0.005 and 0.5 Pa. Breakthrough is largely driven by sample volume and compound volatility (therefore indirectly by temperature) and is independent of sampler type. The presence of significant breakthrough at "typical" sampling conditions is relevant for air monitoring networks, and may lead to under-reporting of more volatile SVOCs.

  2. Soyuz 24 Return Samples: Assessment of Air Quality Aboard the International Space Station

    NASA Technical Reports Server (NTRS)

    James, John T.

    2011-01-01

    Fifteen mini-grab sample containers (m-GSCs) were returned aboard Soyuz. This is the first time all samples were acquired with the mini-grab samplers. The toxicological assessment of 15 m-GSCs from the ISS is shown. The recoveries of the 3 internal standards, C(13)-acetone, fluorobenzene, and chlorobenzene, from the GSCs averaged 75, 97 and 79%, respectively. Formaldehyde badges were not returned on Soyuz 24

  3. Lignite air-steam gasification in the fluidized bed of iron-containing slag catalysts

    SciTech Connect

    Kuznetsov, B.N.; Shchipko, M.L.; Golovin, Yu.

    1995-12-01

    The influence of fluidized bed of iron-containing slag particles on air-steam gasification of powdered Kansk-Achinsk lignite in entrained flow was studied in pilot installation with productivity about 60 kg per hour. Slag of Martin process and boiler slag were used as catalytic active materials until their complete mechanical attrition. Two following methods of catalytic gasification of lignite were compared: the partial gasification in stationary fluidized bed of slag particles with degree of fuel conversion 40-70% and complete gasification in circulating bed of slag particles. In the first case only the most reactive part of fuel is gasified with the simultaneously formation of porous carbon residue with good sorption ability. It was found the catalytic fluidized bed improves heat transfer from combustion to reduction zone of gas-generator and increases the rate of fuel conversion at the temperature range 900-1000{degrees}C. At these temperatures the degree of conversion is depended considerably on the duration time of fuel particles in the catalytic fluidized bed. The influence of catalytic fluidized bed height and velocity of reaction mixture on the temperature profiles in the gas-generator was studied. The optimal relationship was found between the fluidized bed height and velocity of flow which makes possible to produce the gas with higher calorific value at maximum degree of fuel conversion.

  4. Urban air quality assessment using monitoring data of fractionized aerosol samples, chemometrics and meteorological conditions.

    PubMed

    Yotova, Galina I; Tsitouridou, Roxani; Tsakovski, Stefan L; Simeonov, Vasil D

    2016-01-01

    The present article deals with assessment of urban air by using monitoring data for 10 different aerosol fractions (0.015-16 μm) collected at a typical urban site in City of Thessaloniki, Greece. The data set was subject to multivariate statistical analysis (cluster analysis and principal components analysis) and, additionally, to HYSPLIT back trajectory modeling in order to assess in a better way the impact of the weather conditions on the pollution sources identified. A specific element of the study is the effort to clarify the role of outliers in the data set. The reason for the appearance of outliers is strongly related to the atmospheric condition on the particular sampling days leading to enhanced concentration of pollutants (secondary emissions, sea sprays, road and soil dust, combustion processes) especially for ultra fine and coarse particles. It is also shown that three major sources affect the urban air quality of the location studied-sea sprays, mineral dust and anthropogenic influences (agricultural activity, combustion processes, and industrial sources). The level of impact is related to certain extent to the aerosol fraction size. The assessment of the meteorological conditions leads to defining of four downwind patterns affecting the air quality (Pelagic, Western and Central Europe, Eastern and Northeastern Europe and Africa and Southern Europe). Thus, the present study offers a complete urban air assessment taking into account the weather conditions, pollution sources and aerosol fractioning.

  5. Nonuniform air flow in inlets: the effect on filter deposits in the fiber sampling cassette.

    PubMed

    Baron, P A; Chen, C C; Hemenway, D R; O'Shaughnessy, P

    1994-08-01

    Smoke stream studies were combined with a new technique for visualizing a filter deposit from samples used to monitor asbestos or other fibers. Results clearly show the effect of secondary flow vortices within the sampler under anisoaxial sampling conditions. The vortices observed at low wind velocities occur when the inlet axis is situated at angles between 45 degrees and 180 degrees to the motion of the surrounding air. It is demonstrated that the vortices can create a complex nonuniform pattern in the filter deposit, especially when combined with particle settling or electrostatic interactions between the particles and the sampler. Inertial effects also may play a role in the deposit nonuniformity, as well as causing deposition on the cowl surfaces. Changes in the sampler, such as its placement, may reduce these biases. The effects noted are not likely to occur in all sampling situations, but may explain some reports of high variability on asbestos fiber filter samples. The flow patterns observed in this study are applicable to straight, thin-walled inlets. Although only compact particles were used, the air flow patterns and forces involved will have similar effects on fibers of the same aerodynamic diameter.

  6. Laser-induced breakdown spectroscopy for the real-time analysis of mixed waste samples containing Sr

    SciTech Connect

    Barefield, J.E. II; Koskelo, A.C.; Multari, R.A.; Cremers, D.A.; Gamble, T.K.; Han, C.Y.

    1995-05-01

    In this report, the use of Laser-induced breakdown spectroscopy to analyze mixed waste samples containing Sr is discussed. The mixed waste samples investigated include vitrified waste glass and contaminated soil. Compared to traditional analysis techniques, the laser-based method is fast (i.e., analysis times on the order of minutes) and essentially waste free since little or no sample preparation is required. Detection limits on the order of pmm Sr were determined. Detection limits obtained using a fiber optic cable to deliver laser pulses to soil samples containing Cr, Zr, Pb, Be, Cu, and Ni will also be discussed.

  7. Polybrominated diphenyl ethers and alternative flame retardants in air and precipitation samples from the northern Lake Victoria region, East Africa.

    PubMed

    Arinaitwe, Kenneth; Muir, Derek C G; Kiremire, Bernard T; Fellin, Phil; Li, Henrik; Teixeira, Camilla

    2014-01-01

    High volume air and precipitation samples were collected close to the shore of Lake Victoria at Entebbe, Uganda, between October 2008 and July 2010 inclusive. Polybrominated diphenyl ethers (PBDEs) and alternative flame retardants (AFRs) were analyzed by GC-MS. BDEs 47, 99, and 209 were the predominant PBDEs with mean concentrations (in air) of 9.84, 4.38, 8.27 pg m(-3) and mean fluxes in precipitation of 3.40, 6.23, and 7.82 ng m(-2) sample(-1), respectively. 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE), and hexabromocyclododecane (HBCDD), anti- and syn-Dechlorane plus were detected at levels comparable with those of PBDEs. Both PBDEs and AFRs in air generally increased from 2008 to 2010. Elevated PBDE concentrations in air were associated with slow moving low altitude air masses from the region immediately adjacent to the lake, while low concentrations were mostly associated with fast moving westerly and southwesterly air masses. Analysis of the octa- and nona-BDE profiles suggested photolysis and pyrolytic debromination of BDE-209 in the air samples. The highly halogenated and most abundant PBDEs and AFRs in air also predominated in precipitation samples. This is the first study to report flame retardants in high volume air samples and precipitation in Equatorial Africa.

  8. Sampling and Analysis of the Headspace Gas in 3013 Type Plutonium Storage Containers at Los Alamos National Laboratory

    SciTech Connect

    Jackson, Jay M.; Berg, John M.; Hill, Dallas D.; Worl, Laura A.; Veirs, Douglas K.

    2012-07-11

    Department of Energy (DOE) sites have packaged approximately 5200 3013 containers to date. One of the requirements specified in DOESTD-3013, which specifies requirements for packaging plutonium bearing materials, is that the material be no greater than 0.5 weight percent moisture. The containers are robust, nested, welded vessels. A shelf life surveillance program was established to monitor these cans over their 50 year design life. In the event pressurization is detected by radiography, it will be necessary to obtain a head space gas sample from the pressurized container. This technique is also useful to study the head space gas in cans selected for random destructive evaluation. The atmosphere is sampled and the hydrogen to oxygen ratio is measured to determine the effects of radiolysis on the moisture in the container. A system capable of penetrating all layers of a 3013 container assembly and obtaining a viable sample of the enclosed gas and an estimate of internal pressure was designed.

  9. Soyuz 25 Return Samples: Assessment of Air Quality Aboard the International Space Station

    NASA Technical Reports Server (NTRS)

    James, John T.

    2011-01-01

    Six mini-grab sample containers (m-GSCs) were returned aboard Soyuz 25. The toxicological assessment of 6 m-GSCs from the ISS is shown. The recoveries of the 3 internal standards, C-13-acetone, fluorobenzene, and chlorobenzene, from the GSCs averaged 76, 108 and 88%, respectively. Formaldehyde badges were not returned aboard Soyuz 25.

  10. Glyphosate-rich air samples induce IL-33, TSLP and generate IL-13 dependent airway inflammation.

    PubMed

    Kumar, Sudhir; Khodoun, Marat; Kettleson, Eric M; McKnight, Christopher; Reponen, Tiina; Grinshpun, Sergey A; Adhikari, Atin

    2014-11-05

    Several low weight molecules have often been implicated in the induction of occupational asthma. Glyphosate, a small molecule herbicide, is widely used in the world. There is a controversy regarding a role of glyphosate in developing asthma and rhinitis among farmers, the mechanism of which is unexplored. The aim of this study was to explore the mechanisms of glyphosate induced pulmonary pathology by utilizing murine models and real environmental samples. C57BL/6, TLR4-/-, and IL-13-/- mice inhaled extracts of glyphosate-rich air samples collected on farms during spraying of herbicides or inhaled different doses of glyphosate and ovalbumin. The cellular response, humoral response, and lung function of exposed mice were evaluated. Exposure to glyphosate-rich air samples as well as glyphosate alone to the lungs increased: eosinophil and neutrophil counts, mast cell degranulation, and production of IL-33, TSLP, IL-13, and IL-5. In contrast, in vivo systemic IL-4 production was not increased. Co-administration of ovalbumin with glyphosate did not substantially change the inflammatory immune response. However, IL-13-deficiency resulted in diminished inflammatory response but did not have a significant effect on airway resistance upon methacholine challenge after 7 or 21 days of glyphosate exposure. Glyphosate-rich farm air samples as well as glyphosate alone were found to induce pulmonary IL-13-dependent inflammation and promote Th2 type cytokines, but not IL-4 for glyphosate alone. This study, for the first time, provides evidence for the mechanism of glyphosate-induced occupational lung disease.

  11. Size selective isocyanate aerosols personal air sampling using porous plastic foams

    NASA Astrophysics Data System (ADS)

    Khanh Huynh, Cong; Duc, Trinh Vu

    2009-02-01

    As part of a European project (SMT4-CT96-2137), various European institutions specialized in occupational hygiene (BGIA, HSL, IOM, INRS, IST, Ambiente e Lavoro) have established a program of scientific collaboration to develop one or more prototypes of European personal samplers for the collection of simultaneous three dust fractions: inhalable, thoracic and respirable. These samplers based on existing sampling heads (IOM, GSP and cassettes) use Polyurethane Plastic Foam (PUF) according to their porosity to support sampling and separator size of the particles. In this study, the authors present an original application of size selective personal air sampling using chemical impregnated PUF to perform isocyanate aerosols capturing and derivatizing in industrial spray-painting shops.

  12. Atmospheric trace gas measurements with a new clean air sampling system

    SciTech Connect

    Leifer, R.; Sommers, K.; Guggenheim, S.F.

    1981-10-01

    The development of a new clean air sampling system for the Department of Energy's WB-57F aircraft has allowed the analysis of CCl/sub 3/F (Fluorocarbon-11), CCl/sub 2/F/sub 2/ (Fluorocarbon-12), CHClF/sub 2/ (Fluorocarbon-22), C/sub 2/Cl/sub 3/F/sub 3/ (Fluorocarbon-113), CH/sub 4/, CO, CO/sub 2/, N/sub 2/O, CH/sub 3/Cl, CCl/sub 4/, CH/sub 3/CCl/sub 3/, OCS and SF/sub 6/ in tropospheric and stratospheric samples. Samples collected during the interception of the plume from the eruption of Mount St. Helens indicate that OCS was injected into the stratosphere during the eruption. A large CO/sub 2/ gradient was found at 19.2 km on this flight.

  13. Relationship of air sampling rates of semipermeable membrane devices with the properties of organochlorine pesticides.

    PubMed

    Zhu, Xiuhua; Ding, Guanghui; Levy, Walkiria; Jakobi, Gert; Schramm, Karl-Werner

    2011-06-01

    The organochlorine pesticides (OCP) in Eastern-Barvaria at Haidel 1160 m a.s.l. were monitored with a low volume active air sampler and semi-permeable membrane devices (SPMD). The air sampling rates (Rair) of SPMD for OCP were calculated. Quantitative structure-property relationship (QSPR) models of Rair of SPMD were developed for OCP with partial least square (PLS) regression. Quantum chemical descriptors computed by semi-empirical PM6 method were used as predictor variables. The cumulative variance of the dependent variable explained by the PLS components and determined by cross-validation (Q(2)cum), for the optimal models, is 0.637, indicating that the model has good predictive ability and robustness, and could be used to estimate Rair values of OCP. The main factors governing Rair of OCP are intermolecular interactions and the energy required for cave-forming in dissolution of OCP into triolein of SPMD.

  14. Evidence of health impacts of sulfate-and nitrate-containing particles in ambient air.

    PubMed

    Reiss, Richard; Anderson, Elizabeth L; Cross, Carroll E; Hidy, George; Hoel, David; McClellan, Roger; Moolgavkar, Suresh

    2007-05-01

    Ambient particulate matter (PM) is a complex mixture of inorganic and organic compounds. The U.S. Environmental Protection Agency (EPA) regulates PM as a criteria pollutant and promulgates National Ambient Air Quality Standards for it. The PM indicator is based on mass concentration, unspecified as to chemical composition, for specific size fractions. The numerical standards are based on epidemiologic evidence of associations between the various size-related particle mass concentrations as indicators and excess mortality and cardiorespiratory health effects as endpoints. The U.S. National Research Council has stated that more research is needed to differentiate the apparent health effects associated with different particle chemical constituents. Sulfate and nitrate constitute a significant portion of the particle mass in the atmosphere, but are accompanied by similar amounts of carbonaceous material, along with low concentrations of various species, including bioactive organic compounds and redox cycling metals. Extensive animal and human toxicology data show no significant effects for particles consisting only of sulfate and nitrate compounds at levels in excess of ambient air concentrations. A few epidemiologic studies, including both short-term time-series studies and long-term cohort studies, have included the sulfate content of PM as a specific variable in health effect analyses. There are much less data for nitrate. The results from the epidemiologic studies with PM sulfate are inconsistent. A detailed analysis of the time-series epidemiological studies shows that PM sulfate has a weaker "risk factor" than PM2.5 for health effects. Since sulfate is correlated with PM2.5, this result is inconsistent with sulfate having a strong health influence. However, there are many limitations with these types of studies that warrant caution for any comparison between a chemical component and mass concentration. In total, the epidemiologic and toxicologic evidence provide

  15. Results of Self-Absorption Study on the Versapor 3000 Filters for Radioactive Particulate Air Sampling

    SciTech Connect

    Barnett, J. Matthew; Cullinan, Valerie I.; Barnett, Debra S.; Trang-Le, Truc LT; Bliss, Mary; Greenwood, Lawrence R.; Ballinger, Marcel Y.

    2009-02-17

    Since the mid-1980s, Pacific Northwest National Laboratory (PNNL) has used a value of 0.85 as the correction factor for self absorption of activity for particulate radioactive air samples collected from building exhaust for environmental monitoring. This value accounts for activity that cannot be detected by direct counting of alpha and beta particles. Emissions can be degraded or blocked by filter fibers for particles buried in the filter material or by inactive dust particles collected with the radioactive particles. These filters are used for monitoring air emissions from PNNL stacks for radioactive particles. This paper describes an effort to re-evaluate self-absorption effects in particulate radioactive air sample filters (Versapor® 3000, 47 mm diameter) used at PNNL. There were two methods used to characterize the samples. Sixty samples were selected from the archive for acid digestion to compare the radioactivity measured by direct gas-flow proportional counting of filters to the results obtained after acid digestion of the filter and counting again by gas-flow proportional detection. Thirty different sample filters were selected for visible light microscopy to evaluate filter loading and particulate characteristics. Mass-loading effects were also considered. Filter ratios were calculated by dividing the initial counts by the post-digestion counts with the expectation that post-digestion counts would be higher because digestion would expose radioactivity embedded in the filter in addition to that on top of the filter. Contrary to expectations, the post digestion readings were almost always lower than initial readings and averaged approximately half the initial readings for both alpha and beta activity. Before and after digestion readings appeared to be related to each other, but with a low coefficient of determination (R^2) value. The ratios had a wide range of values indicating that this method did not provide sufficient precision to quantify self

  16. Processes to Open the Container and the Sample Catcher of the Hayabusa Returned Capsule in the Planetary Material Sample Curation Facility of JAXA

    NASA Technical Reports Server (NTRS)

    Fujimura, A.; Abe, M.; Yada, T.; Nakamura, T.; Noguchi, T.; Okazaki, R.; Ishibashi, Y.; Shirai, K.; Okada, T.; Yano, H.; Zolensky, M. E.; Sandford, S.; Ueno, M.; Mukai, T.; Yoshikawa, M.; Kawaguchi, J.

    2011-01-01

    Japanese spacecraft Hayabusa, which returned from near-Earth-asteroid Itokawa, successfully returned its reentry capsule to the Earth, the Woomera Prohibited Area in Australia in Jun 13th, 2010, as detailed in another paper [1]. The capsule introduced into the Planetary Material Sample Curation Facility in the Sagamihara campus of JAXA in the early morning of June 18th. Hereafter, we describe a series of processes for the returned capsule and the container to recover gas and materials in there. A transportation box of the recovered capsule was cleaned up on its outer surface beforehand and introduced into the class 10,000 clean room of the facility. Then, the capsule was extracted from the box and its plastic bag was opened and checked and photographed the outer surface of the capsule. The capsule was composed of the container, a backside ablator, a side ablator, an electronic box and a supporting frame. The container consists of an outer lid, an inner lid, a frame for latches, a container and a sample catcher, which is composed of room A and B and a rotational cylinder. After the first check, the capsule was packed in a plastic bag with N2 again, and transferred to the Chofu campus in JAXA, where the X-ray CT instrument is situated. The first X-ray CT analysis was performed on the whole returned capsule for confirming the conditions of latches and O-ring seal of the container. The analysis showed that the latches of the container should have worked normally, and that the double Orings of the container seemed to be sealed its sample catcher with no problem. After the first X-ray CT, the capsule was sent back to Sagamihara and introduced in the clean room to exclude the electronic box and the side ablator from the container by hand tools. Then the container with the backside ablator was set firmly to special jigs to fix the lid of container tightly to the container and set to a milling machine. The backside ablator was drilled by the machine to expose heads of bolts

  17. A survey of recent results in passive sampling of water and air by semipermeable membrane devices

    USGS Publications Warehouse

    Prest, Harry F.; Huckins, James N.; Petty, Jimmie D.; Herve, Sirpa; Paasivirta, Jaakko; Heinonen, Pertti

    1995-01-01

    A survey is presented of some recent results for passive sampling of water and air for trace organic contaminants using lipid-filled semipermeable membrane devices (SPMDs). Results of water sampling for trace organochlorine compounds using simultaneously exposed SPMDs and the most universally applied biomonitor (bivalves) are discussed. In general, the total amounts of accumulated analytes available for analysis in bivalves and SPMDs were comparable. However, SPMD controls typically had negligible levels of contamination, which was not always the case for transplanted bivalves, even after prolonged depuration prior to exposure. In surveys of the spatial trends of organochlorines at a series of sites, data from bivalves and SPMDs provided the same picture of contaminant distribution and severity. An exception was ionizable contaminants such as the chlorinated phenolic compounds and their transformation products found in pulp mill effluents. In these cases the two monitoring approaches compliment each other, i.e. what is not found in bivalves appears in SPMDs and vice versa. SPMDs have also been applied in environments where biomonitoring is not feasible. SPMDs have shown their utility in studies of trace levels of polyaromatic hydrocarbons by locating and characterizing point sources. An example is given of their application to the calculation of contaminant half-lives from aqueous SPMD residues, a direct measurement of the persistence of contaminants in an environmental compartment. Similarly, results of air sampling with SPMDs in a relatively pristine coastal location are cited which reveal a tremendous enhancement in p,p′-DDE relative to open ocean values.

  18. Contemporary-use pesticides in personal air samples during pregnancy and blood samples at delivery among urban minority mothers and newborns.

    PubMed Central

    Whyatt, Robin M; Barr, Dana B; Camann, David E; Kinney, Patrick L; Barr, John R; Andrews, Howard F; Hoepner, Lori A; Garfinkel, Robin; Hazi, Yair; Reyes, Andria; Ramirez, Judyth; Cosme, Yesenia; Perera, Frederica P

    2003-01-01

    We have measured 29 pesticides in plasma samples collected at birth between 1998 and 2001 from 230 mother and newborn pairs enrolled in the Columbia Center for Children's Environmental Health prospective cohort study. Our prior research has shown widespread pesticide use during pregnancy among this urban minority cohort from New York City. We also measured eight pesticides in 48-hr personal air samples collected from the mothers during pregnancy. The following seven pesticides were detected in 48-83% of plasma samples (range, 1-270 pg/g): the organophosphates chlorpyrifos and diazinon, the carbamates bendiocarb and 2-isopropoxyphenol (metabolite of propoxur), and the fungicides dicloran, phthalimide (metabolite of folpet and captan), and tetrahydrophthalimide (metabolite of captan and captafol). Maternal and cord plasma levels were similar and, except for phthalimide, were highly correlated (p < 0.001). Chlorpyrifos, diazinon, and propoxur were detected in 100% of personal air samples (range, 0.7-6,010 ng/m(3)). Diazinon and propoxur levels were significantly higher in the personal air of women reporting use of an exterminator, can sprays, and/or pest bombs during pregnancy compared with women reporting no pesticide use or use of lower toxicity methods only. A significant correlation was seen between personal air level of chlorpyrifos, diazinon, and propoxur and levels of these insecticides or their metabolites in plasma samples (maternal and/or cord, p < 0.05). The fungicide ortho-phenylphenol was also detected in 100% of air samples but was not measured in plasma. The remaining 22 pesticides were detected in 0-45% of air or plasma samples. Chlorpyrifos, diazinon, propoxur, and bendiocarb levels in air and/or plasma decreased significantly between 1998 and 2001. Findings indicate that pesticide exposures are frequent but decreasing and that the pesticides are readily transferred to the developing fetus during pregnancy. PMID:12727605

  19. Evaluation of five sampling methods for Liposcelis entomophila (Enderlein) and L. decolor (Pearman) (Psocoptera: Liposcelididae) in steel bins containing wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An evaluation of five sampling methods for studying psocid population levels was conducted in two steel bins containing 32.6 metric tonnes of wheat in Manhattan, KS. Psocids were sampled using a 1.2-m open-ended trier, corrugated cardboard refuges placed on the underside of the bin hatch or the surf...

  20. 77 FR 22550 - Approval and Promulgation of Air Quality Implementation Plans; Illinois; Small Container...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-16

    ... Container Exemption From VOC Coating Rules AGENCY: Environmental Protection Agency (EPA). ACTION: Proposed... of amendments to the Illinois Administrative Code by adding ] a ``small container exemption''...

  1. 77 FR 31727 - Approval and Promulgation of Air Quality Implementation Plans; Illinois; Small Container...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-30

    ... Container Exemption From VOC Coating Rules AGENCY: Environmental Protection Agency (EPA). ACTION: Withdrawal... Illinois SIP that added a ``small container exemption'' for pleasure craft surface coating operations...

  2. Sampling of Breathable Air in U.S. Navy Sonar Domes

    DTIC Science & Technology

    1994-03-01

    USS Kidd 4/92 154 ( DDG - 993 ) USS Donald B. Beary (FF- 6/92 41 1085) USS Truett 6/92 149 (FF-1095) USS San Jacinto 6/92 70 (CG-56) USS Hue City 9/92 32...pressure-tight bulkhead in the center of the dome. On the DD-963, and DDG - 993 , and CG-47 class ships (i.e., destroyers and 5 cruisers), samples of dome air...Command. NAVSEA S9165-AH-MMA-010. Technical manual for sonar dome rubber window SDRW-1 for DD-963, DDG - 993 , and CG-47 class vessels. Revision 1,

  3. Evaluation of septum-capped vials for storage of gas samples during air transport.

    PubMed

    Glatzel, Stephan; Well, Reinhard

    2008-01-01

    In order to provide information on the suitability of commonly used gas storage vials for air transport, we tested two vial types on their ability to preserve defined nitrous oxide concentrations and excess pressure when exposed to low pressure, low temperature and puncture by needles. Unlike in Crimp Cap vials, in Exetainers no nitrous oxide loss following low pressure storage was detectable. Tightness of Exetainers following multiple puncture was best using a small needle diameter. Pressure loss following 5, 10, or 25 punctures was lowest in the Exetainers. We conclude that Exetainers are suitable for storing gas samples for an extended period of time during aircraft transport.

  4. Extreme 13C depletion of CCl2F2 in firn air samples from NEEM, Greenland

    NASA Astrophysics Data System (ADS)

    Zuiderweg, A.; Holzinger, R.; Martinerie, P.; Schneider, R.; Kaiser, J.; Witrant, E.; Etheridge, D.; Petrenko, V.; Blunier, T.; Röckmann, T.

    2013-01-01

    A series of 12 high volume air samples collected from the S2 firn core during the North Greenland Eemian Ice Drilling (NEEM) 2009 campaign have been measured for mixing ratio and stable carbon isotope composition of the chlorofluorocarbon CFC-12 (CCl2F2). While the mixing ratio measurements compare favorably to other firn air studies, the isotope results show extreme 13C depletion at the deepest measurable depth (65 m), to values lower than δ13C = -80‰ vs. VPDB (the international stable carbon isotope scale), compared to present day surface tropospheric measurements near -40‰. Firn air modeling was used to interpret these measurements. Reconstructed atmospheric time series indicate even larger depletions (to -120‰) near 1950 AD, with subsequent rapid enrichment of the atmospheric reservoir of the compound to the present day value. Mass-balance calculations show that this change is likely to have been caused by a large change in the isotopic composition of anthropogenic CFC-12 emissions, probably due to technological advances in the CFC production process over the last 80 yr, though direct evidence is lacking.

  5. Extreme 13C depletion of CCl2F2 in firn air samples from NEEM, Greenland

    NASA Astrophysics Data System (ADS)

    Zuiderweg, A.; Holzinger, R.; Martinerie, P.; Schneider, R.; Kaiser, J.; Witrant, E.; Etheridge, D.; Rubino, M.; Petrenko, V.; Blunier, T.; Röckmann, T.

    2012-07-01

    A series of 12 high volume air samples collected from the S2 firn core during the North Greenland Eemian Ice Drilling (NEEM) 2009 campaign have been measured for mixing ratio and stable carbon isotope composition of the chlorofluorocarbon CFC-12 (CCl2F2). While the mixing ratio measurements compare favorably to other firn air studies, the isotope results show extreme 13C depletion at the deepest measurable depth (65 m), to values lower than δ13C = -80‰ vs. VPDB (the international stable carbon isotope scale), compared to present day surface tropospheric measurements near -40‰. Firn air modeling was used to interpret these measurements. Reconstructed atmospheric time series indicate even larger depletions (to -120‰) near 1950 AD, with subsequent rapid enrichment of the atmospheric reservoir of the compound to the present day value. Mass-balance calculations show that this change must have been caused by a large change in the isotopic composition of anthropogenic CFC-12 emissions, probably due to technological changes in the CFC production process over the last 80 yr. Propagating the mass-balance calculations into the future demonstrates that as emissions decrease to zero, isotopic fractionation by the stratospheric sinks will lead to continued 13C enrichment in atmospheric CFC-12.

  6. IMPROVED METHOD FOR THE STORAGE OF GROUND WATER SAMPLES CONTAINING VOLATILE ORGANIC ANALYTES

    EPA Science Inventory

    The sorption of volatile organic analytes from water samples by the Teflon septum surface used with standard glass 40-ml sample collection vials was investigated. Analytes tested included alkanes, isoalkanes, olefins, cycloalkanes, a cycloalkene, monoaromatics, a polynuclear arom...

  7. Estimation of sampling error uncertainties in observed surface air temperature change in China

    NASA Astrophysics Data System (ADS)

    Hua, Wei; Shen, Samuel S. P.; Weithmann, Alexander; Wang, Huijun

    2016-06-01

    This study examines the sampling error uncertainties in the monthly surface air temperature (SAT) change in China over recent decades, focusing on the uncertainties of gridded data, national averages, and linear trends. Results indicate that large sampling error variances appear at the station-sparse area of northern and western China with the maximum value exceeding 2.0 K2 while small sampling error variances are found at the station-dense area of southern and eastern China with most grid values being less than 0.05 K2. In general, the negative temperature existed in each month prior to the 1980s, and a warming in temperature began thereafter, which accelerated in the early and mid-1990s. The increasing trend in the SAT series was observed for each month of the year with the largest temperature increase and highest uncertainty of 0.51 ± 0.29 K (10 year)-1 occurring in February and the weakest trend and smallest uncertainty of 0.13 ± 0.07 K (10 year)-1 in August. The sampling error uncertainties in the national average annual mean SAT series are not sufficiently large to alter the conclusion of the persistent warming in China. In addition, the sampling error uncertainties in the SAT series show a clear variation compared with other uncertainty estimation methods, which is a plausible reason for the inconsistent variations between our estimate and other studies during this period.

  8. EPA's Response to the February 2014 Release of Radioactive Material from the Waste Isolation Pilot Plant (WIPP): EPA's WIPP Air Sampling Data from April 2014

    EPA Pesticide Factsheets

    In April 2014, U.S. Environmental Protection Agency (EPA) environmental monitoring and assessment team members reviewed DOE's air sampling plan, visited DOE's air samplers and placed air samplers onsite near existing DOE samplers to corroborate results.

  9. Ram-air sample collection device for a chemical warfare agent sensor

    DOEpatents

    Megerle, Clifford A.; Adkins, Douglas R.; Frye-Mason, Gregory C.

    2002-01-01

    In a surface acoustic wave sensor mounted within a body, the sensor having a surface acoustic wave array detector and a micro-fabricated sample preconcentrator exposed on a surface of the body, an apparatus for collecting air for the sensor, comprising a housing operatively arranged to mount atop the body, the housing including a multi-stage channel having an inlet and an outlet, the channel having a first stage having a first height and width proximate the inlet, a second stage having a second lower height and width proximate the micro-fabricated sample preconcentrator, a third stage having a still lower third height and width proximate the surface acoustic wave array detector, and a fourth stage having a fourth height and width proximate the outlet, where the fourth height and width are substantially the same as the first height and width.

  10. Comparison of air samples, nasal swabs, ear-skin swabs and environmental dust samples for detection of methicillin-resistant Staphylococcus aureus (MRSA) in pig herds.

    PubMed

    Agersø, Y; Vigre, H; Cavaco, L M; Josefsen, M H

    2014-08-01

    To identify a cost-effective and practical method for detection of methicillin-resistant Staphylococcus aureus (MRSA) in pig herds, the relative sensitivity of four sample types: nasal swabs, ear-skin (skin behind the ears) swabs, environmental dust swabs and air was compared. Moreover, dependency of sensitivity on within-herd prevalence was estimated. spa-typing was applied in order to study strain diversity. The sensitivity of one air sample was equal to the sensitivity of ten pools of five nasal swabs and relatively independent of within-herd prevalence [predicted to be nearly perfect (99%) for within-herd prevalence ⩾25%]. The results indicate that taking swabs of skin behind the ears (ten pools of five) was even more sensitive than taking nasal swabs (ten pools of five) at the herd level and detected significantly more positive samples. spa types t011, t034 and t4208 were observed. In conclusion, MRSA detection by air sampling is easy to perform, reduces costs and analytical time compared to existing methods, and is recommended for initial testing of herds. Ear-skin swab sampling may be more sensitive for MRSA detection than air sampling or nasal swab sampling.

  11. Proportional counter device for detecting electronegative species in an air sample

    DOEpatents

    Allman, S.L.; Chen, F.C.; Chen, C.H.

    1994-03-08

    Apparatus for detecting an electronegative species comprises an analysis chamber, an inlet communicating with the analysis chamber for admitting a sample containing the electronegative species and an ionizable component, a radioactive source within the analysis chamber for emitting radioactive energy for ionizing a component of the sample, a proportional electron detector within the analysis chamber for detecting electrons emitted from the ionized component, and a circuit for measuring the electrons and determining the presence of the electronegative species by detecting a reduction in the number of available electrons due to capture of electrons by the electronegative species. 2 figures.

  12. Proportional counter device for detecting electronegative species in an air sample

    DOEpatents

    Allman, Steve L.; Chen, Fang C.; Chen, Chung-Hsuan

    1994-01-01

    Apparatus for detecting an electronegative species comprises an analysis chamber, an inlet communicating with the analysis chamber for admitting a sample containing the electronegative species and an ionizable component, a radioactive source within the analysis chamber for emitting radioactive energy for ionizing a component of the sample, a proportional electron detector within the analysis chamber for detecting electrons emitted from the ionized component, and a circuit for measuring the electrons and determining the presence of the electronegative species by detecting a reduction in the number of available electrons due to capture of electrons by the electronegative species.

  13. Evaluation of physical sampling efficiency for cyclone-based personal bioaerosol samplers in moving air environments.

    PubMed

    Su, Wei-Chung; Tolchinsky, Alexander D; Chen, Bean T; Sigaev, Vladimir I; Cheng, Yung Sung

    2012-09-01

    The need to determine occupational exposure to bioaerosols has notably increased in the past decade, especially for microbiology-related workplaces and laboratories. Recently, two new cyclone-based personal bioaerosol samplers were developed by the National Institute for Occupational Safety and Health (NIOSH) in the USA and the Research Center for Toxicology and Hygienic Regulation of Biopreparations (RCT & HRB) in Russia to monitor bioaerosol exposure in the workplace. Here, a series of wind tunnel experiments were carried out to evaluate the physical sampling performance of these two samplers in moving air conditions, which could provide information for personal biological monitoring in a moving air environment. The experiments were conducted in a small wind tunnel facility using three wind speeds (0.5, 1.0 and 2.0 m s(-1)) and three sampling orientations (0°, 90°, and 180°) with respect to the wind direction. Monodispersed particles ranging from 0.5 to 10 μm were employed as the test aerosols. The evaluation of the physical sampling performance was focused on the aspiration efficiency and capture efficiency of the two samplers. The test results showed that the orientation-averaged aspiration efficiencies of the two samplers closely agreed with the American Conference of Governmental Industrial Hygienists (ACGIH) inhalable convention within the particle sizes used in the evaluation tests, and the effect of the wind speed on the aspiration efficiency was found negligible. The capture efficiencies of these two samplers ranged from 70% to 80%. These data offer important information on the insight into the physical sampling characteristics of the two test samplers.

  14. 'Pseudomonas saudimassiliensis' sp. nov. a new bacterial species isolated from air samples in the urban environment of Makkah, Saudi Arabia.

    PubMed

    Azhar, E I; Papadioti, A; Bibi, F; Ashshi, A M; Raoult, D; Angelakis, E

    2017-03-01

    We report here the main characteristics of 'Pseudomonas saudimassiliensis' strain 12M76_air(T) (CSUR P1220), a new species of the Pseudomonas genus that was isolated from air samples in the city environment of Makkah, Saudi Arabia, during the pilgrim period of Hajj 2012.

  15. 'Lysinibacillus saudimassiliensis' sp. nov., a new bacterial species isolated from air samples in the urban environment of Makkah, Saudi Arabia.

    PubMed

    Papadioti, A; Azhar, E I; Bibi, F; Jiman-Fatani, A; Aboushoushah, S M; Yasir, M; Raoult, D; Angelakis, E

    2017-03-01

    We report here the main characteristics of 'Lysinibacillus saudimassiliensis' strain 13S34_air(τ) (CSUR = P1222), a new species of the Lysinibacillus genus that was isolated from air samples in the city environment of Makkah, Saudi Arabia, during the pilgrim period of Hajj 2012.

  16. 'Jeotgalicoccus saudimassiliensis' sp. nov., a new bacterial species isolated from air samples in the urban environment of Makkah, Saudi Arabia.

    PubMed

    Papadioti, A; Azhar, E I; Bibi, F; Jiman-Fatani, A; Aboushoushah, S M; Yasir, M; Raoult, D; Angelakis, E

    2017-01-01

    We report here the main characteristics of 'Jeotgalicoccus saudimassiliensis' strain 13MG44_air(T) (CSUR P1221), a new species of the Jeotgalicoccus genus that was isolated from air samples in the city environment of Makkah, Saudi Arabia, during the pilgrim period of Hajj 2012.

  17. 'Arthrobacter saudimassiliensis' sp. nov. a new bacterial species isolated from air samples in the urban environment of Makkah, Saudi Arabia.

    PubMed

    Papadioti, A; Azhar, E I; Bibi, F; Jiman-Fatani, A; Aboushoushah, S M; Yasir, M; Raoult, D; Angelakis, E

    2017-03-01

    We report here the main characteristics of 'Arthrobacter saudimassiliensis' strain 11W110_air(T) (CSUR P1223), a new species of the Arthrobacter genus that was isolated from air samples in the city environment of Makkah, Saudi Arabia, during the pilgrim period of Hajj 2012.

  18. Can the use of deactivated glass fibre filters eliminate sorption artefacts associated with active air sampling of perfluorooctanoic acid?

    PubMed

    Johansson, Jana H; Berger, Urs; Cousins, Ian T

    2017-05-01

    Experimental work was undertaken to test whether gaseous perfluorooctanoic acid (PFOA) sorbs to glass fibre filters (GFFs) during air sampling, causing an incorrect measure of the gas-particle equilibrium distribution. Furthermore, tests were performed to investigate whether deactivation by siliconisation prevents sorption of gaseous PFOA to filter materials. An apparatus was constructed to closely simulate a high-volume air sampler, although with additional features allowing introduction of gaseous test compounds into an air stream stripped from particles. The set-up enabled investigation of the sorption of gaseous test compounds to filter media, eliminating any contribution from particles. Experiments were performed under ambient outdoor air conditions at environmentally relevant analyte concentrations. The results demonstrate that gaseous PFOA sorbs to GFFs, but that breakthrough of gaseous PFOA on the GFFs occurs at trace-level loadings. This indicates that during high volume air sampling, filters do not quantitatively capture all the PFOA in the sampled air. Experiments with siliconised GFFs showed that this filter pre-treatment reduced the sorption of gaseous PFOA, but that sorption still occurred at environmentally relevant air concentrations. We conclude that deactivation of GFFs does not allow for the separation of gaseous and particle bound perfluorinated carboxylic acids (PFCAs) during active air sampling. Consequently, the well-recognised theory that PFCAs do not prevail as gaseous species in the atmosphere may be based on biased measurements. Caution should be taken to ensure that this artefact will not bias the conclusions of future field studies.

  19. Air sampling of aromatic hydrocarbons in the presence of ozone by solid-phase microextraction.

    PubMed

    Xiong, Gouhua; Koziel, Jacek A; Pawliszyn, Janusz

    2004-01-30

    Effects of ozone on air sampling of standard gas mixtures of aromatic hydrocarbons were tested using solid-phase microextraction (SPME). Standard concentrations of ozone ranging from 10 ppb (v/v) to 6400 ppm (v/v) were generated using an in-house built ozone generator based on corona discharge. Effects of temperature, discharge voltage, and oxygen flow on the ozone generation were tested. The working dc voltage had the greatest effect on generated ozone concentration and was proportional to the ozone concentration. Generation temperature and oxygen flow rate were inversely proportional to ozone concentrations. Produced ozone was mixed with standard benzene, toluene, ethylbenzene, and xylenes (BTEX) gas at less than 100 ppb (v/v). Air samples were collected with poly(dimethylsiloxane) (PDMS) 100 microm SPME fibers and analyzed by gas chromatography (GC)-flame ionization detection (FID) and GC-MS. Significant reductions of BTEX concentrations were observed. In addition, some products of BTEX-ozone-oxygen reactions were identified. SPME worked well as a rapid sampler for BTEX and BTEX-ozone-oxygen reaction products. No significant deterioration of the PDMS coating and no significant reduction of absorption capacity were observed after repeated exposure to ozone.

  20. Optimal media for use in air sampling to detect cultivable bacteria and fungi in the pharmacy.

    PubMed

    Weissfeld, Alice S; Joseph, Riya Augustin; Le, Theresa V; Trevino, Ernest A; Schaeffer, M Frances; Vance, Paula H

    2013-10-01

    Current guidelines for air sampling for bacteria and fungi in compounding pharmacies require the use of a medium for each type of organism. U.S. Pharmacopeia (USP) chapter <797> (http://www.pbm.va.gov/linksotherresources/docs/USP797PharmaceuticalCompoundingSterileCompounding.pdf) calls for tryptic soy agar with polysorbate and lecithin (TSApl) for bacteria and malt extract agar (MEA) for fungi. In contrast, the Controlled Environment Testing Association (CETA), the professional organization for individuals who certify hoods and clean rooms, states in its 2012 certification application guide (http://www.cetainternational.org/reference/CAG-009v3.pdf?sid=1267) that a single-plate method is acceptable, implying that it is not always necessary to use an additional medium specifically for fungi. In this study, we reviewed 5.5 years of data from our laboratory to determine the utility of TSApl versus yeast malt extract agar (YMEA) for the isolation of fungi. Our findings, from 2,073 air samples obtained from compounding pharmacies, demonstrated that the YMEA yielded >2.5 times more fungal isolates than TSApl.

  1. Evaluation of bioaerosol sampling techniques for the detection of Chlamydophila psittaci in contaminated air.

    PubMed

    Van Droogenbroeck, Caroline; Van Risseghem, Marleen; Braeckman, Lutgart; Vanrompay, Daisy

    2009-03-16

    Chlamydophila (C.) psittaci, a category B bioterrorism agent, causes respiratory disease in birds and psittacosis or parrot fever in man. The disease spreads aerogenically and no vaccines are available for either birds or man. Highly sensitive C. psittaci bioaerosol monitoring methods are unavailable. We evaluated: (1) dry filtration for collecting C. psittaci from contaminated air using different samplers and membrane filters, (2) impingement into different liquid collection media by use of the AGI-30 impinger and the BioSampler and (3) impaction into newly designed C. psittaci media utilizing the MAS-100 aerosol impactor. For personal bioaerosol sampling, we recommend the use of a gelatin filter in combination with the IOM inhalable dust sampler at an airflow rate of 2L/min. This allowed the detection of 10 organisms of C. psittaci by both PCR and culture. For stationary bioaerosol monitoring, sampling 1000L of air in 10min with the MAS-100 impactor and ChlamyTrap 1 impaction medium was most efficient and made it possible to detect 1 and 10 C. psittaci organisms by PCR and culture, respectively. ChlamyTrap 1 in combination with the MAS-100 impactor might also be applicable for bioaerosol monitoring of viruses.

  2. Evaluating spatial distribution and seasonal variation of phthalates using passive air sampling in southern India.

    PubMed

    Sampath, Srimurali; Selvaraj, Krishna Kumar; Shanmugam, Govindaraj; Krishnamoorthy, Vimalkumar; Chakraborty, Paromita; Ramaswamy, Babu Rajendran

    2017-02-01

    Usage of phthalates as plasticizers has resulted in worldwide occurrence and is becoming a serious concern to human health and environment. However, studies on phthalates in Indian atmosphere are lacking. Therefore, we studied the spatio-temporal trends of six major phthalates in Tamil Nadu, southern India, using passive air samplers. Phthalates were ubiquitously detected in all the samples and the average total phthalates found in decreasing order is pre-monsoon (61 ng m(-3)) > summer (52 ng m(-3)) > monsoon (17 ng m(-3)). Largely used phthalates, dibutylphthalate (DBP) and diethylhexlphthalate (DEHP) were predominantly found in all the seasons with contribution of 11-31% and 59-68%, respectively. The highest total phthalates was observed in summer at an urban location (836 ng m(-3)). Furthermore, through principal component analysis, potential sources were identified as emissions from additives of plasticizers in the polymer industry and the productions of adhesives, building materials and vinyl flooring. Although inhalation exposure of infants was higher than other population segments (toddlers, children and adults), exposure levels were found to be safe for people belonging to all ages based on reference dose (RfD) and tolerable daily intake (TDI) values. This study first attempted to report seasonal trend based on atmospheric monitoring using passive air sampling technique and exposure risk together.

  3. Preterm Cord Blood Contains a Higher Proportion of Immature Hematopoietic Progenitors Compared to Term Samples

    PubMed Central

    Podestà, Marina; Bruschettini, Matteo; Cossu, Claudia; Sabatini, Federica; Dagnino, Monica; Romantsik, Olga; Spaggiari, Grazia Maria; Ramenghi, Luca Antonio; Frassoni, Francesco

    2015-01-01

    Background Cord blood contains high number of hematopoietic cells that after birth disappear. In this paper we have studied the functional properties of the umbilical cord blood progenitor cells collected from term and preterm neonates to establish whether quantitative and/or qualitative differences exist between the two groups. Methods and Results Our results indicate that the percentage of total CD34+ cells was significantly higher in preterm infants compared to full term: 0.61% (range 0.15–4.8) vs 0.3% (0.032–2.23) p = 0.0001 and in neonates <32 weeks of gestational age (GA) compared to those ≥32 wks GA: 0.95% (range 0.18–4.8) and 0.36% (0.15–3.2) respectively p = 0.0025. The majority of CD34+ cells co-expressed CD71 antigen (p<0.05 preterm vs term) and grew in vitro large BFU-E, mostly in the second generation. The subpopulations CD34+CD38- and CD34+CD45- resulted more represented in preterm samples compared to term, conversely, Side Population (SP) did not show any difference between the two group. The absolute number of preterm colonies (CFCs/10microL) resulted higher compared to term (p = 0.004) and these progenitors were able to grow until the third generation maintaining an higher proportion of CD34+ cells (p = 0.0017). The number of colony also inversely correlated with the gestational age (Pearson r = -0.3001 p<0.0168). Conclusions We found no differences in the isolation and expansion capacity of Endothelial Colony Forming Cells (ECFCs) from cord blood of term and preterm neonates: both groups grew in vitro large number of endothelial cells until the third generation and showed a transitional phenotype between mesenchymal stem cells and endothelial progenitors (CD73, CD31, CD34 and CD144)The presence, in the cord blood of preterm babies, of high number of immature hematopoietic progenitors and endothelial/mesenchymal stem cells with high proliferative potential makes this tissue an important source of cells for developing new cells therapies

  4. Concentrations of polybrominated diphenyl ethers (PBDEs) in matched samples of human milk, dust and indoor air.

    PubMed

    Toms, Leisa-Maree L; Hearn, Laurence; Kennedy, Karen; Harden, Fiona; Bartkow, Michael; Temme, Christian; Mueller, Jochen F

    2009-08-01

    Polybrominated diphenyl ethers (PBDEs) are lipophilic, persistent pollutants found worldwide in environmental and human samples. Exposure pathways for PBDEs remain unclear but may include food, air and dust. The aim of this study was to conduct an integrated assessment of PBDE exposure and human body burden using 10 matched samples of human milk, indoor air and dust collected in 2007-2008 in Brisbane, Australia. In addition, temporal analysis was investigated comparing the results of the current study with PBDE concentrations in human milk collected in 2002-2003 from the same region. PBDEs were detected in all matrices and the median concentrations of BDEs -47 and -209 in human milk, air and dust were: 4.2 and 0.3 ng/g lipid; 25 and 7.8 pg/m(3); and 56 and 291 ng/g dust, respectively. Significant correlations were observed between the concentrations of BDE-99 in air and human milk (r=0.661, p=0.038) and BDE-153 in dust and BDE-183 in human milk (r=0.697, p=0.025). These correlations do not suggest causal relationships - there is no hypothesis that can be offered to explain why BDE-153 in dust and BDE-183 in milk are correlated. The fact that so few correlations were found in the data could be a function of the small sample size, or because additional factors, such as sources of exposure not considered or measured in the study, might be important in explaining exposure to PBDEs. There was a slight decrease in PBDE concentrations from 2002-2003 to 2007-2008 but this may be due to sampling and analytical differences. Overall, average PBDE concentrations from these individual samples were similar to results from pooled human milk collected in Brisbane in 2002-2003 indicating that pooling may be an efficient, cost-effective strategy of assessing PBDE concentrations on a population basis. The results of this study were used to estimate an infant's daily PBDE intake via inhalation, dust ingestion and human milk consumption. Differences in PBDE intake of individual

  5. ANASORB{reg_sign} 747 - A universal sorbent for air sampling?

    SciTech Connect

    Harper, M.

    1997-12-31

    A sorbent to be used for air sampling must meet certain performance criteria including sample background, capacity, stability, and recovery. Anasorb{sup R} 747 is a proprietary 20/40 mesh beaded active carbon prepared from raw materials with a very low ash content in a process which creates a regular pore structure. The background is very low for both inorganic and organic species, and the surface is more inert and less hydrophilic than coconut charcoal, while capacity is similar. The low catalytic activity of the surface means samples of many reactive compounds remain stable for longer periods. The sorbent is compatible with most solvent systems in use (e.g. carbon disulfide, methylene chloride, methanol, dimethyformamide). Anasorb 747 can be coated with chemicals for efficient adsorption of inorganic gases, which can be analyzed at very low levels because of low background interference. A large number of validated sampling methods use Anasorb 747, including methods from OSHA and NIOSH, corporate industrial hygiene laboratories, various branches of the EPA, and international agencies. These methods refer to around fifty different gases and vapors. Although this sorbent is not compatible with some compounds (e.g. low molecular weight aldehydes) it is quite close to being of universal application.

  6. Numerical Study of a Winged Container Moving in an Air Tunnel

    NASA Astrophysics Data System (ADS)

    Shibani, W. M.; Zulkafli, M. F.; Basuno, B.

    2016-11-01

    This study explores the movement of an object placed in an air tunnel. In expectation this exploration leads to obtaining a suitable shape of the object and the flow parameters, the object moves along the air tunnel has a particular trajectory. This study used the body of the main object is a cube in which a rectangular wing of aspect ratio 2 is set in the middle of body object. The object can be used as a carrier to transport goods from one place to another through an air tunnel. Three types wing-cube configurations, they are namely wing- cube configuration with airfoil sections (1) FX63-137, (2) NACA 4412, and (3) NACA 0012 are evaluated by using Fluent's software. The flow problems are treated as an internal flow problem with the assumption that the pressure ratio between the inlet and outlet of the air tunnel is 700 N/m2. The flow is treated as turbulent flow with k — ɛ as its turbulence modelling. In this respect Fluent uses a SIMPLE scheme for solving their governing equation of fluid motion. Their computational results on the way the object moves along the air tunnel, it had been the carrier which uses airfoil NACA 0012 has better performance than the carrier that uses airfoil FX 63-137 or airfoil NACA 4412. This research work gives contribution in understanding the movement of the carrier in the form wing-cube configuration inside an air tunnel.

  7. Total Particulate Matter Air Sampling Data (TEOM) from Los Alamos National Laboratory

    DOE Data Explorer

    LANL measures the total particulate mass concentration in the air on a routine basis as well as during incidents that may affect ambient air. The collected data is added to the Air Quality Index (AQI). AQI is an index for reporting daily air quality. It tells you how clean or polluted your air is, and what associated health effects might be a concern for you. The AQI focuses on health effects you may experience within a few hours or days after breathing polluted air. EPA calculates the AQI for five major air pollutants regulated by the Clean Air Act.

  8. An evaluation of analytical methods, air sampling techniques, and airborne occupational exposure of metalworking fluids.

    PubMed

    Verma, Dave K; Shaw, Don S; Shaw, M Lorraine; Julian, Jim A; McCollin, Shari-Ann; des Tombe, Karen

    2006-02-01

    This article summarizes an assessment of air sampling and analytical methods for both oil and water-based metalworking fluids (MWFs). Three hundred and seventy-four long-term area and personal airborne samples were collected at four plants using total (closed-face) aerosol samplers and thoracic samplers. A direct-reading device (DustTrak) was also used. The processes sampled include steel tube making, automotive component manufacturing, and small part manufacturing in a machine shop. The American Society for Testing and Materials (ASTM) Method PS42-97 of analysis was evaluated in the laboratory. This evaluation included sample recovery, determination of detection limits, and stability of samples during storage. Results of the laboratory validation showed (a) the sample recovery to be about 87%, (b) the detection limit to be 35 microg, and (c) sample stability during storage at room temperature to decline rapidly within a few days. To minimize sample loss, the samples should be stored in a freezer and analyzed within a week. The ASTM method should be the preferred method for assessing metalworking fluids (MWFs). The ratio of thoracic aerosol to total aerosol ranged from 0.6 to 0.7. A similar relationship was found between the thoracic extractable aerosol and total extractable aerosol. The DustTrak, with 10-microm sampling head, was useful in pinpointing the areas of potential exposure. MWF exposure at the four plants ranged from 0.04 to 3.84 mg/m3 with the geometric mean ranging between 0.22 to 0.59 mg/m3. Based on this data and the assumption of log normality, MWF exposures are expected to exceed the National Institute for Occupational Safety and Health recommended exposure limit of 0.5 mg/m3 as total mass and 0.4 mg/m3 as thoracic mass about 38% of the time. In addition to controlling airborne MWF exposure, full protection of workers would require the institution of programs for fluid management and dermal exposure prevention.

  9. Sampling medium side resistance to uptake of semivolatile organic compounds in passive air samplers.

    PubMed

    Zhang, Xianming; Tsurukawa, Masahiro; Nakano, Takeshi; Lei, Ying D; Wania, Frank

    2011-12-15

    Current theory of the uptake of semivolatile organic compounds in passive air samplers (PAS) assumes uniform chemical distribution and no kinetic resistance within the passive sampling media (PSM) such as polystyrene-divinylbenzene resin (XAD) and polyurethane foam (PUF). However, these assumptions have not been tested experimentally and are challenged by some recently reported observations. To test the assumptions, we performed kinetic uptake experiments indoors using cylindrical PSM that had been concentrically segmented into three layers. Both XAD and PUF were positioned in the same type of sampler housing to eliminate the variation caused by the different housing designs, which enabled us to quantify differences in uptake caused by the properties of the PSM. Duplicated XAD (PUF) samples were retrieved after being deployed for 0, 1 (0.5), 2 (1), 4 (2), 8 (4), 12 (8), and 24 (12) weeks. Upon retrieval, the PSM layers were separated and analyzed individually for PCBs. Passive sampling rates (R) were lower for heavier PCB homologues. Within a homologue group, R for XAD was higher than that for PUF, from which we infer that the design of the "cylindrical can" housing typically used for XAD PAS lowers the R compared to the "double bowl" shelter commonly used for PUF-disk PAS. Outer layers of the PSM sequestered much higher levels of PCBs than inner layers, indicative of a kinetic resistance to chemical transfer within the PSM. The effective diffusivities for chemical transfer within PSM were derived and were found negatively correlated with the partition coefficients between the PSM and air. Based on the results, we conclude that the PSM-side kinetic resistance should be considered when investigating factors influencing R and when deriving R based on the loss of depuration compounds.

  10. Evaluation of sampling methods for toxicological testing of indoor air particulate matter.

    PubMed

    Tirkkonen, Jenni; Täubel, Martin; Hirvonen, Maija-Riitta; Leppänen, Hanna; Lindsley, William G; Chen, Bean T; Hyvärinen, Anne; Huttunen, Kati

    2016-09-01

    There is a need for toxicity tests capable of recognizing indoor environments with compromised air quality, especially in the context of moisture damage. One of the key issues is sampling, which should both provide meaningful material for analyses and fulfill requirements imposed by practitioners using toxicity tests for health risk assessment. We aimed to evaluate different existing methods of sampling indoor particulate matter (PM) to develop a suitable sampling strategy for a toxicological assay. During three sampling campaigns in moisture-damaged and non-damaged school buildings, we evaluated one passive and three active sampling methods: the Settled Dust Box (SDB), the Button Aerosol Sampler, the Harvard Impactor and the National Institute for Occupational Safety and Health (NIOSH) Bioaerosol Cyclone Sampler. Mouse RAW264.7 macrophages were exposed to particle suspensions and cell metabolic activity (CMA), production of nitric oxide (NO) and tumor necrosis factor (TNFα) were determined after 24 h of exposure. The repeatability of the toxicological analyses was very good for all tested sampler types. Variability within the schools was found to be high especially between different classrooms in the moisture-damaged school. Passively collected settled dust and PM collected actively with the NIOSH Sampler (Stage 1) caused a clear response in exposed cells. The results suggested the higher relative immunotoxicological activity of dust from the moisture-damaged school. The NIOSH Sampler is a promising candidate for the collection of size-fractionated PM to be used in toxicity testing. The applicability of such sampling strategy in grading moisture damage severity in buildings needs to be developed further in a larger cohort of buildings.

  11. 24-HOUR DIFFUSIVE SAMPLING OF TOXIC VOCS IN AIR ONTO CARBOPACK X SOLID ADSORBENT FOLLOWED BY THERMAL DESORPTION/GC/MS ANALYSIS - LABORATORY STUDIES

    EPA Science Inventory

    Diffusive sampling of a mixture of 42 volatile organic compounds (VOCs) in humidified, purified air onto the solid adsorbent Carbopack X was evaluated under controlled laboratory conditions. The evaluation included variations in sample air temperature, relative humidity, and ozon...

  12. CTEPP STANDARD OPERATING PROCEDURE FOR COLLECTION OF FIXED SITE INDOOR AND OUTDOOR AIR SAMPLES FOR PERSISTENT ORGANIC POLLUTANTS (SOP-2.12)

    EPA Science Inventory

    This SOP describes the procedures to set up, calibrate, initiate and terminate air sampling for persistent organic pollutants. This method is used to sample air, indoors and outdoors, at homes and at day care centers over a 48-hr period.

  13. Sampling plans for the psocids Liposcelis entomophila and Liposcelis decolor (Psocoptera: Liposcelididae) in steel bins containing wheat.

    PubMed

    Opit, G P; Throne, J E; Flinn, P W

    2009-08-01

    Psocids are an emerging problem in grain storage, handling, and processing facilities in the United States. We used data from two steel bins each containing 32.6 metric tonnes of wheat, Triticum aestivum L., to develop sampling plans for Liposcelis entomophila (Enderlein), Liposcelis decolor (Pearman) (both Psocoptera: Liposcelididae), and a mixture of the two species. Taylor's coefficients a (a sampling factor) and b (an index of aggregation) for these pests were calculated and incorporated into sampling protocols to improve accuracy. The optimal binomial sample sizes for estimating populations of these psocids at densities of < 25 psocids per refuge were large; therefore, we recommend the use of numerical sampling within this range of densities. Numerical sampling of L. entomophila and L. decolor at densities of < 25 psocids per refuge should not be too laborious given the low psocid numbers involved; we recommend using 10 refuges per bin. For presence-absence sampling of L. entomophila or L. decolor, 20 refuges per bin should be used at densities of 25-100 psocids per refuge. The sampling plans we have developed based on the use of cardboard refuges are convenient for use in steel bins containing wheat because they are inexpensive, provide a rapid assessment of psocid population incidence, and are easy to implement. These sampling plans can be used to monitor populations of and the efficacy of management strategies used against L. entomophila and L. decolor.

  14. In vitro effects of pollutants from particulate and volatile fractions of air samples-day and night variability.

    PubMed

    Novák, Jiří; Giesy, John P; Klánová, Jana; Hilscherová, Klára

    2013-09-01

    Chemicals in air were characterized for potential interference with signaling of estrogen, androgen, and arylhydrocarbon (AhR) receptors, which are known to play an important role in endocrine-disruptive changes in vivo. Previously, effects of this type have been studied mainly in particulate matter in the ambient air from various localities. In this study, both volatile and particulate fractions of air from three sites in Banja Luka region (Bosnia and Herzegovina) were investigated to describe the distribution of endocrine-disrupting contaminants on a small spatial scale. Circadian variability of air pollution was investigated by collecting samples during both day and night. Air samples collected from urban localities at night were more potent in producing the AhR-mediated effects than those collected during daytime. This trend was not observed at the reference rural location. None of the samples showed significant estrogenic or androgenic activity. On the other hand, anti-androgenicity was detected in both particulate and vapor phases, while anti-estrogenicity was detected only in the particulate fraction of air from all localities. The AhR-mediated potencies of samples were associated primarily with non-persistent compounds. Based on the concentrations of 28 individual compounds, PAHs accounted for approximately 30 % of the AhR-mediated potency determined by the bioassay. The results show that there can be a significant difference between levels of bioactive compounds in air between daytime and nighttime.

  15. PCB-containing wood floor finish is a likely source of elevated PCBs in residents' blood, household air and dust: a case study of exposure

    PubMed Central

    Rudel, Ruthann A; Seryak, Liesel M; Brody, Julia G

    2008-01-01

    Background Polychlorinated biphenyls (PCBs) are persistent pollutants identified worldwide as human blood and breast milk contaminants. Because they bioaccumulate, consumption of meat, fish, and dairy products predicts human blood concentrations. PCBs were also used widely in building materials, including caulks and paints, but few studies have evaluated the contribution of these exposures to body burden. Methods In an earlier study, we detected PCBs in indoor air in 31% of 120 homes on Cape Cod, MA. Two of the homes had much higher concentrations than the rest, so we retested to verify the initial finding, evaluate blood PCB concentrations of residents, and identify the PCB source. Results Air and dust concentrations remained elevated over 5 years between initial and follow-up sampling. Blood serum concentrations of PCBs in residents of the homes were generally elevated above the 95th percentile of a representative sample of the US population. Serum concentrations in residents and air and dust concentrations were especially high in a home where a resident reported use of PCB-containing floor finish in the past, and where the floor of one room was sanded and refinished just prior to sample collection. Conclusion This case-study suggests that PCB residues in homes may be more significant contributors to overall exposure than diet for some people, and that use of a commercially-available PCB-containing wood floor finish in residences during the 1950s and 1960s is an overlooked but potentially important source of current PCB exposure in the general population. PMID:18201376

  16. A flow cytometric method for enumeration of lymphocyte sub-populations in sample containing lysis-resistant red blood cells.

    PubMed

    Kasinrerk, Watchara

    2003-05-01

    Determination of lymphocyte sub-populations is usually carried out by flow cytometry using two-color immunophenotyping reagent. By this technique, however, the combination of FSC and SSC with CD45-FITC/CD14-PE is unable to identify the lymphocyte population in a sample containing lysis-resistant red blood cells (RBC). The actual values of lymphocyte sub-populations, therefore, cannot be determined in these RBC contaminated samples. To overcome this problem, we describe here the use of 7-aminoactinomycin D (7-AAD) to exclude lysis-resistant RBC from white blood cells (WBC). By adding 7-AAD, lymphocytes of samples containing RBC could be identified by using FL3/SSC, therefore, the actual number of lymphocyte sub-populations of the stained cells was obtained. We have proved that 7-AAD can be used to exclude contaminated RBC and has no effect on the measurement of lymphocyte sub-populations by using two-color immunophenotyping reagent. In routine blood samples that contain lysis-resistant RBC, 7-AAD markedly increased the purity of lymphocytes in the lymphocyte gate to >95% and the lymphocyte sub-populations therefore could be correctly determined. The described method is inexpensive, simple and gives successful analysis of lymphocyte sub-populations in a sample containing lysis-resistant RBC.

  17. Spectral fingerprinting of polycyclic aromatic hydrocarbons in high-volume ambient air samples by constant energy synchronous luminescence spectroscopy

    USGS Publications Warehouse

    Kerkhoff, M.J.; Lee, T.M.; Allen, E.R.; Lundgren, D.A.; Winefordner, J.D.

    1985-01-01

    A high-volume sampler fitted with a glass-fiber filter and backed by polyurethane foam (PUF) was employed to collect airborne particulate and gas-phase polycylic aromatic hydrocarbons (PAHs) in ambient air. Samples were collected from four sources representing a range of environmental conditions: gasoline engine exhaust, diesel engine exhaust, air near a heavily traveled interstate site, and air from a moderately polluted urban site. Spectral fingerprints of the unseparated particulate and gas-phase samples were obtained by constant energy synchronous luminescence spectroscopy (CESLS). Five major PAHs in the gas-phase extracts were characterized and estimated. The compatibility of a high-volume sampling method using polyurethane foam coupled with CESLS detection is explored for use as a screening technique for PAHs in ambient air. ?? 1985 American Chemical Society.

  18. A methodology for the evaluation of the turbine jet engine fragment threat to generic air transportable containers

    SciTech Connect

    Harding, D.C.; Pierce, J.D.

    1993-06-01

    Uncontained, high-energy gas turbine engine fragments are a potential threat to air-transportable containers carried aboard jet aircraft. The threat to a generic example container is evaluated by probability analyses and penetration testing to demonstrate the methodology to be used in the evaluation of a specific container/aircraft/engine combination. Fragment/container impact probability is the product of the uncontained fragment release rate and the geometric probability that a container is in the path of this fragment. The probability of a high-energy rotor burst fragment from four generic aircraft engines striking one of the containment vessels aboard a transport aircraft is approximately 1.2 {times} 10{sup {minus}9} strikes/hour. Finite element penetration analyses and tests can be performed to identify specific fragments which have the potential to penetrate a generic or specific containment vessel. The relatively low probability of engine fragment/container impacts is primarily due to the low release rate of uncontained, hazardous jet engine fragments.

  19. Evaluation of a modified sampling method for molecular analysis of air microflora.

    PubMed

    Lech, T; Ziembinska-Buczynska, A

    2015-04-10

    A serious issue concerning the durability of economically important materials for humans related to cultural heritage is the process of biodeterioration. As a result of this phenomenon, priceless works of art, documents, and old prints have undergone a process of decomposition caused by microorganisms. Therefore, it is important to constantly monitor the presence and diversity of microorganisms in exposition rooms and storage areas of historical objects. In addition, the use of molecular biology tools for conservation studies will enable detailed research as well as reduce the time needed to perform the analyses compared with using conventional methods related to microbiology and conservation. The aim of this study was to adapt the sampling indoor air method for direct DNA extraction from microorganisms, including evaluating the extracted DNA quality and concentration. The obtained DNA was used to study the diversity of mold fungi in indoor air using polymerase chain reaction-denaturing gradient gel electrophoresis in specific archives and museum environments. The research was conducted in 2 storage rooms of the National Archives in Krakow and in 1 exposition room of the Archaeological Museum in Krakow (Poland).

  20. Cluster analysis of passive air sampling data based on the relative composition of persistent organic pollutants.

    PubMed

    Liu, Xiande; Wania, Frank

    2014-03-01

    The development of passive air samplers has allowed the measurement of time-integrated concentrations of persistent organic pollutants (POPs) within spatial networks on a variety of scales. Cluster analysis of POP composition may enhance the interpretation of such spatial data. Several methodological aspects of the application of cluster analysis are discussed, including the influence of a dominant pollutant, the role of PAS duplication, and comparison of regional studies. Relying on data from six regional studies in North and South America, Africa, and Asia, we illustrate here how cluster analysis can be used to extract information and gain insights into POP sources and atmospheric transport contributions. Cluster analysis allows classification of PAS samples into those with significant local source contributions and those that represent regional fingerprints. Local emissions, atmospheric transport, and seasonal cycles are identified as being among the major factors determining the variation in POP composition at many sites. By complementing cluster analysis with meteorological data such as air mass back-trajectories, terrain, as well as geographical and socio-economic aspects, a comprehensive picture of the atmospheric contamination of a region by POPs emerges.

  1. Air-Based Remediation Workshop - Section 1 Sampling And Analysis Revelant To Air-Based Remediation Technologies

    EPA Science Inventory

    Pursant to the EPA-AIT Implementing Arrangement 7 for Technical Environmental Collaboration, Activity 11 "Remediation of Contaminated Sites," the USEPA Office of International Affairs Organized a Force Air Remediation Workshop in Taipei to deliver expert training to the Environme...

  2. Solvent Selection for Pressurized Liquid Extraction of Polymeric Sorbents Used in Air Sampling

    PubMed Central

    Primbs, Toby; Genualdi, Susan; Simonich, Staci

    2014-01-01

    Pressurized liquid extraction (PLE) was evaluated as a method for extracting semivolatile organic compounds (SOCs) from air sampling media; including quartz fiber filter (QFF), polyurethane foam (PUF), and a polystyrene divinyl benzene copolymer (XAD-2). Hansen solubility parameter plots were used to aid in the PLE solvent selection in order to reduce both co-extraction of polyurethane and save time in evaluating solvent compatibility during the initial steps of method development. A PLE solvent composition of 75:25% hexane:acetone was chosen for PUF. The XAD-2 copolymer was not solubilized under the PLE conditions used. The average percent PLE recoveries (and percent relative standard deviations) of 63 SOCs, including polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and organochlorine, amide, triazine, thiocarbamate, and phosphorothioate pesticides, were 76.7 (6.2), 79.3 (8.1), and 93.4 (2.9) % for the QFF, PUF, and XAD-2, respectively. PMID:18220448

  3. Sampling of power plant stacks for air toxic emissions: Topical report for Phases 1 and 2

    SciTech Connect

    1995-02-21

    Under contract with the US Department of Energy (DE-AC22-92PCO0367), Pittsburgh Energy Technology Center, Radian Corporation has conducted a test program to collect and analyze size-fractionated stack gas particulate samples for selected inorganic hazardous air pollutants (HAPS). Specific goals of the program are (1) the collection of one-gram quantities of size-fractionated stack gas particulate matter for bulk (total) and surface chemical charactization, and (2) the determination of the relationship between particle size, bulk and surface (leachable) composition, and unit load. The information obtained from this program identifies the effects of unit load, particle size, and wet FGD system operation on the relative toxicological effects of exposure to particulate emissions.

  4. Spectrophotometric determination of nitrogen dioxide in air and nitrite in water and soil samples

    SciTech Connect

    Pandurangappa, M.; Balasubramanian, N.

    1995-02-01

    A sensitive spectrophotometric method for the determination of nitrogen dioxide in air and nitrite in water and soil samples is described. Nitrogen dioxide in air is fixed as nitrite ion in alkaline sodium arsenite or in triethanolamine absorber solutions. The method is based on the diazo coupling reaction between p-nitro aniline and 1-hydroxy-2-naphthoic acid. The azo dye formed under aqueous condition has an absorption maximum at 585nm and obeys Beer`s law over the range 0-25{mu}g of nitrite. The colour system is stable for 72h. The relative standard deviation is 2.7% for ten determinations at 15{mu}g of nitrite. The dye is extracted with 1:1 isoamyl alcohol-IBMK mixture and stabilisation with methanolic potassium hydroxide showed {lambda}{sub max} at 610nm. It obeys Beer`s law over the range 0-4{mu}g of nitrite. The colour system is stable for 40h in organic phase and the relative standard deviation is 2.5% for ten determinations at 3{mu}g of nitrite. The molar absorptivity of the colour system is 3.68 x 10{sup 4} Lmol{sup {minus}1} cm{sup {minus}1}. The effect of interfering gases and other ions on the determination of nitrite is described. The developed method has been applied for the determination of residual nitrogen dioxide gas present in the laboratory fume cupboard and automobile exhaust gases. In addition, the method has been applied for the determination of nitrite and nitrate in samples like water, soil and radiator coolants.

  5. Evaluation of sampling and analytical methods for the determination of chlorodifluoromethane in air.

    PubMed

    Seymour, M J; Lucas, M F

    1993-05-01

    In January 1989, the Occupational Safety and Health Administration (OSHA) published revised permissible exposure limits (PELs) for 212 compounds and established PELs for 164 additional compounds. In cases where regulated compounds did not have specific sampling and analytical methods, methods were suggested by OSHA. The National Institute for Occupational Safety and Health (NIOSH) Manual of Analytical Methods (NMAM) Method 1020, which was developed for 1,1,2-trichloro-1,2,2-trifluoroethane, was suggested by OSHA for the determination of chlorodifluoromethane in workplace air. Because this method was developed for a liquid and chlorodifluoromethane is a gas, the ability of NMAM Method 1020 to adequately sample and quantitate chlorodifluoromethane was questioned and tested by researchers at NIOSH. The evaluation of NMAM Method 1020 for chlorodifluoromethane showed that the capacity of the 100/50-mg charcoal sorbent bed was limited, the standard preparation procedure was incorrect for a gas analyte, and the analyte had low solubility in carbon disulfide. NMAM Method 1018 for dichlorodifluoromethane uses two coconut-shell charcoal tubes in series, a 400/200-mg tube followed by a 100/50-mg tube, which are desorbed with methylene chloride. This method was evaluated for chlorodifluoromethane. Test atmospheres, with chlorodifluoromethane concentrations from 0.5-2 times the PEL were generated. Modifications of NMAM Method 1018 included changes in the standard preparation procedure, and the gas chromatograph was equipped with a capillary column. These revisions to NMAM 1018 resulted in a 96.5% recovery and a total precision for the method of 7.1% for chlorodifluoromethane. No significant bias in the method was found. Results indicate that the revised NMAM Method 1018 is suitable for the determination of chlorodifluoromethane in workplace air.

  6. GUIDE TO CALCULATING TRANSPORT EFFICIENCY OF AEROSOLS IN OCCUPATIONAL AIR SAMPLING SYSTEMS

    SciTech Connect

    Hogue, M.; Hadlock, D.; Thompson, M.; Farfan, E.

    2013-11-12

    This report will present hand calculations for transport efficiency based on aspiration efficiency and particle deposition losses. Because the hand calculations become long and tedious, especially for lognormal distributions of aerosols, an R script (R 2011) will be provided for each element examined. Calculations are provided for the most common elements in a remote air sampling system, including a thin-walled probe in ambient air, straight tubing, bends and a sample housing. One popular alternative approach would be to put such calculations in a spreadsheet, a thorough version of which is shared by Paul Baron via the Aerocalc spreadsheet (Baron 2012). To provide greater transparency and to avoid common spreadsheet vulnerabilities to errors (Burns 2012), this report uses R. The particle size is based on the concept of activity median aerodynamic diameter (AMAD). The AMAD is a particle size in an aerosol where fifty percent of the activity in the aerosol is associated with particles of aerodynamic diameter greater than the AMAD. This concept allows for the simplification of transport efficiency calculations where all particles are treated as spheres with the density of water (1g cm-3). In reality, particle densities depend on the actual material involved. Particle geometries can be very complicated. Dynamic shape factors are provided by Hinds (Hinds 1999). Some example factors are: 1.00 for a sphere, 1.08 for a cube, 1.68 for a long cylinder (10 times as long as it is wide), 1.05 to 1.11 for bituminous coal, 1.57 for sand and 1.88 for talc. Revision 1 is made to correct an error in the original version of this report. The particle distributions are based on activity weighting of particles rather than based on the number of particles of each size. Therefore, the mass correction made in the original version is removed from the text and the calculations. Results affected by the change are updated.

  7. Selective isolation of Avian influenza virus (AIV) from cloacal samples containing AIV and Newcastle disease virus.

    PubMed

    El Zowalaty, Mohamed E; Chander, Yogesh; Redig, Patrick T; Abd El Latif, Hemmat K; El Sayed, Mona A; Goyal, Sagar M

    2011-03-01

    Avian influenza viruses (AIVs) are important zoonotic pathogens whose natural reservoir is waterfowl. In addition to AIV, waterfowl are often coinfected with other viruses, such as the paramyxoviruses, of which Newcastle disease virus (NDV) is of particular importance because of the highly virulent nature of certain strains of this virus for domestic poultry. In routine surveillance of waterfowl for AIV, a number of cloacal samples were encountered that were positive for AIV by real-time reverse transcription polymerase chain reaction (RT-PCR), but did not yield AIV by inoculation in embryonated chicken eggs. On further testing, these samples were also positive for NDV by conventional RT-PCR. It was hypothesized that if both NDV and AIV are present in a sample, the former may overgrow AIV yielding false-negative AIV results. Such samples were treated with chicken anti-NDV polyclonal antiserum and then inoculated in embryonated chicken eggs. Several samples were found to be positive for different subtypes of AIV, indicating that, in the presence of mixed infection with NDV and AIV, it is imperative to remove the influence of NDV, so a true picture of AIV prevalence emerges. An additional benefit is that information on the circulation of NDV in these birds sheds light on their epidemiologic and ecologic significance.

  8. Gluten-containing grains skew gluten assessment in oats due to sample grind non-homogeneity.

    PubMed

    Fritz, Ronald D; Chen, Yumin; Contreras, Veronica

    2017-02-01

    Oats are easily contaminated with gluten-rich kernels of wheat, rye and barley. These contaminants are like gluten 'pills', shown here to skew gluten analysis results. Using R-Biopharm R5 ELISA, we quantified gluten in gluten-free oatmeal servings from an in-market survey. For samples with a 5-20ppm reading on a first test, replicate analyses provided results ranging <5ppm to >160ppm. This suggests sample grinding may inadequately disperse gluten to allow a single accurate gluten assessment. To ascertain this, and characterize the distribution of 0.25-g gluten test results for kernel contaminated oats, twelve 50g samples of pure oats, each spiked with a wheat kernel, showed that 0.25g test results followed log-normal-like distributions. With this, we estimate probabilities of mis-assessment for a 'single measure/sample' relative to the <20ppm regulatory threshold, and derive an equation relating the probability of mis-assessment to sample average gluten content.

  9. 77 FR 22497 - Approval and Promulgation of Air Quality Implementation Plans; Illinois; Small Container...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-16

    ... AGENCY 40 CFR Part 52 Approval and Promulgation of Air Quality Implementation Plans; Illinois; Small... final rule. SUMMARY: EPA is approving a revision to the Illinois State Implementation plan (SIP... proposed approval at 76 FR 74014). During that rulemaking the American Coatings Association (ACA)...

  10. 78 FR 23495 - Approval and Promulgation of Air Quality Implementation Plans; Illinois; Small Container...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-19

    ... AGENCY 40 CFR Part 52 Approval and Promulgation of Air Quality Implementation Plans; Illinois; Small.... SUMMARY: EPA is approving a revision to the Illinois State Implementation plan (SIP) submitted by the... rulemaking, the American Coatings Association (ACA) commented to Illinois EPA that many VOC...

  11. U.S. Air Force School of Aerospace Medicine Laboratory Sampling and Analysis Guide

    DTIC Science & Technology

    2016-11-15

    suspect these compounds are present in your sample. Titanium dioxide (N7300) and sodium hydroxide (N7401) are available through subcontract...amber bottle, reduce residual chlorine by adding sodium sulfite, preserve with HCl to pHɚ, cool to 4°C, no headspace. Anions EPA 300 Plastic...of sodium sulfite. Adjust pHɚ by adding HCl, cool to 4°C. Hold time is 14 days. Recommended container size is two 1-L glass bottles. Residual

  12. Improved method for the storage of groundwater samples containing volatile organic analytes

    PubMed

    Kovacs; Kampbell

    1999-04-01

    The sorption of volatile organic analytes from water samples by the Teflon septum surface used with standard glass 40-ml sample collection vials was investigated. Analytes tested included alkanes, isoalkanes, olefins, cycloalkanes, a cycloalkene, monoaromatics, a polynuclear aromatic, and two chloroethenes. Both laboratory prepared test mix solutions and petroleum contaminated groundwater from three field sites were tested. A rapid loss of n-alkane and isoalkane concentrations (>10%) was observed within 24 h when stored at room temperature. Aliphatic losses were also observed (>10%) over a 21-day holding period when samples were held at 4 degrees C. Loss of the less sorptive analytes was demonstrated by exposing analyte solutions to greater Teflon surface areas. The demonstrated sorption of aliphatics from water samples by Teflon-lined septa indicates that the accuracy of volatile petroleum hydrocarbon determinations may be reduced by the traditional storage method. An alternative storage protocol is reported combining a lead foil septum surface and 1% (w/w) tribasic sodium phosphate dodecahydrate (Na3PO4. 12H2O) preservative. This method prevented loss of the test analytes, including alkanes and isoalkanes for at least 21 days at room temperature.

  13. Biochemical and cellular effects of electrophiles present in ambient air samples

    NASA Astrophysics Data System (ADS)

    Iwamoto, Noriko; Nishiyama, Akira; Eiguren-Fernandez, Arantzazu; Hinds, William; Kumagai, Yoshito; Froines, John R.; Cho, Arthur K.; Shinyashiki, Masaru

    2010-04-01

    Ambient vapor-phase samples collected in Riverside, California had shown that both redox and electrophilic activity were present, with the vapor phase containing higher levels of electrophiles than the particle phase. In this study, the biochemical effects of the vapor-phase electrophiles were examined using the purified thiol proteins, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), protein tyrosine phosphatase 1B (PTP1B) and KELCH-1 like ECH-associated protein 1 (Keap1). The results demonstrated that the thiol proteins were inactivated by the vapor-phase samples through covalent modifications. Next, two cellular responses, epidermal growth factor receptor (EGFR)/mitogen-activated protein (MAP) kinase and NF-E2-related factor 2 (Nrf2), to the ambient vapor-phase samples were assessed in A549 and RAW 264.7 cell lines, respectively. The vapor-phase samples, at non-oxidative concentrations, increased phosphorylation of EGFR, which is negatively regulated by PTP1B, and its downstream MAP kinase, extracellular signal-regulated kinase (ERK)1/2. Activation of Nrf2, which requires Keap1 alkylation, and expression of its downstream proteins were also observed. The electrophilic compounds present in ambient vapor-phase were shown to modify cellular proteins through covalent modification and to activate diverse cellular responses that can lead to inflammatory and adaptive responses.

  14. Sampling, storage, and analysis of C2-C7 non-methane hydrocarbons from the US National Oceanic and Atmospheric Administration Cooperative Air Sampling Network glass flasks.

    PubMed

    Pollmann, Jan; Helmig, Detlev; Hueber, Jacques; Plass-Dülmer, Christian; Tans, Pieter

    2008-04-25

    An analytical technique was developed to analyze light non-methane hydrocarbons (NMHC), including ethane, propane, iso-butane, n-butane, iso-pentane, n-pentane, n-hexane, isoprene, benzene and toluene from whole air samples collected in 2.5l-glass flasks used by the National Oceanic and Atmospheric Administration, Earth System Research Laboratory, Global Monitoring Division (NOAA ESRL GMD, Boulder, CO, USA) Cooperative Air Sampling Network. This method relies on utilizing the remaining air in these flasks (which is at below-ambient pressure at this stage) after the completion of all routine greenhouse gas measurements from these samples. NMHC in sample aliquots extracted from the flasks were preconcentrated with a custom-made, cryogen-free inlet system and analyzed by gas chromatography (GC) with flame ionization detection (FID). C2-C7 NMHC, depending on their ambient air mixing ratios, could be measured with accuracy and repeatability errors of generally < or =10-20%. Larger deviations were found for ethene and propene. Hexane was systematically overestimated due to a chromatographic co-elution problem. Saturated NMHC showed less than 5% changes in their mixing ratios in glass flask samples that were stored for up to 1 year. In the same experiment ethene and propene increased at approximately 30% yr(-1). A series of blank experiments showed negligible contamination from the sampling process and from storage (<10 pptv yr(-1)) of samples in these glass flasks. Results from flask NMHC analyses were compared to in-situ NMHC measurements at the Global Atmospheric Watch station in Hohenpeissenberg, Germany. This 9-months side-by-side comparison showed good agreement between both methods. More than 94% of all data comparisons for C2-C5 alkanes, isoprene, benzene and toluene fell within the combined accuracy and precision objectives of the World Meteorological Organization Global Atmosphere Watch (WMO-GAW) for NMHC measurements.

  15. Uncertainties in Air Exchange using Continuous-Injection, Long-Term Sampling Tracer-Gas Methods

    SciTech Connect

    Sherman, Max H.; Walker, Iain S.; Lunden, Melissa M.

    2013-12-01

    The PerFluorocarbon Tracer (PFT) method is a low-cost approach commonly used for measuring air exchange in buildings using tracer gases. It is a specific application of the more general Continuous-Injection, Long-Term Sampling (CILTS) method. The technique is widely used but there has been little work on understanding the uncertainties (both precision and bias) associated with its use, particularly given that it is typically deployed by untrained or lightly trained people to minimize experimental costs. In this article we will conduct a first-principles error analysis to estimate the uncertainties and then compare that analysis to CILTS measurements that were over-sampled, through the use of multiple tracers and emitter and sampler distribution patterns, in three houses. We find that the CILTS method can have an overall uncertainty of 10-15percent in ideal circumstances, but that even in highly controlled field experiments done by trained experimenters expected uncertainties are about 20percent. In addition, there are many field conditions (such as open windows) where CILTS is not likely to provide any quantitative data. Even avoiding the worst situations of assumption violations CILTS should be considered as having a something like a ?factor of two? uncertainty for the broad field trials that it is typically used in. We provide guidance on how to deploy CILTS and design the experiment to minimize uncertainties.

  16. Volatile N-nitrosamines in environmental tobacco smoke: Sampling, analysis, emission factors, and indoor air exposures

    SciTech Connect

    Mahanama, K.R.R.; Daisey, J.M.

    1996-05-01

    A more convenient sampling and analysis method for the volatile N-nitrosamines (VNA) in environmental tobacco smoke (ETS), using commercially available Thermosorb/N cartridges, was developed and validated. Using the method, emission factors for the two major VNA in ETS were determined in a room-sized environmental chamber for six commercial cigarette brands, which together accounted for 62.5% of the total market in California in 1990. The average emission factors were 565{+-}115 and 104{+-}20 ng per cigarette for N-nitrosodimethylamine and N-nitrosopyrrolidine, respectively. The emission factors were used to estimate VNA exposures from ETS in a typical office building and an average residence. Indoor concentrations of N,N-dimethylnitrosamine from ETS for these modeled scenarios were less than 10% of the reported median outdoor concentration. This median outdoor concentration, however, includes many measurements made in source-dominated areas and may be considerably higher than one based on more representative sampling of outdoor air. 35 refs., 4 tabs.

  17. Sampling of power plant stacks for air toxic emissions: Final report for Phases 1 and 2

    SciTech Connect

    1995-04-28

    A test program to collect and analyze size-fractionated stack gas particulate samples for selected inorganic hazardous air pollutants (HAPs) was conducted . Specific goals of the program are (1) the collection of one-gram quantities of size-fractionated stack gas particulate matter for bulk (total) and surface chemical characterization, and (2) the determination of the relationship between particle size, bulk and surface (leachable) composition, and unit load. The information obtained from this program identifies the effects of unit load, particle size, and wet FGD system operation on the relative toxicological effects of exposure to particulate emissions. Field testing was conducted in two phases. The Phase I field program was performed over the period of August 24 through September 20, 1992, at the Tennessee Valley Authority Widows Creek Unit 8 Power Station, located near Stevenson (Jackson County), Alabama, on the Tennessee River. Sampling activities for Phase II were conducted from September 11 through October 14, 1993. Widows Creek Unit 8 is a 575-megawatt plant that uses bituminous coal averaging 3.7% sulfur and 13% ash. Downstream of the boiler, a venture wet scrubbing system is used for control of both sulfur dioxide and particulate emissions. There is no electrostatic precipitator (ESP) in this system. This system is atypical and represents only about 5% of the US utility industry. However, this site was chosen for this study because of the lack of information available for this particulate emission control system.

  18. Review of PCBs in US Schools: A Brief History, Estimate of the Number of Impacted Schools, and an Approach for Evaluating Indoor Air Samples

    PubMed Central

    Herrick, Robert F.; Stewart, James H.; Allen, Joseph G.

    2015-01-01

    PCBs in building materials such as caulks and sealants are a largely unrecognized source of contamination in the building environment. Schools are of particular interest, as the period of extensive school construction (about 1950 to 1980) coincides with the time of greatest use of PCBs as plasticizers in building materials. In the United States, we estimate that the number of schools with PCB in building caulk ranges from 12, 960 to 25, 920 based upon the number of schools built in the time of PCB use, and the proportion of buildings found to contain PCB caulk and sealants. Field and laboratory studies have demonstrated that PCBs from both interior and exterior caulking can be the source of elevated PCB air concentrations in these buildings, at levels that exceed health-based PCB exposure guidelines for building occupants. Air sampling in buildings containing PCB caulk has shown that the airborne PCB concentrations can be highly variable, even in repeat samples collected within a room. Sampling and data analysis strategies that recognize this variability can provide the basis for informed decision making about compliance with health-based exposure limits, even in cases where small numbers of samples are taken. The health risks posed by PCB exposures, particularly among children, mandate precautionary approaches to managing PCBs in building materials. PMID:25940477

  19. Structure of phospholipid monolayers containing poly(ethylene glycol) lipids at the air-water interface

    SciTech Connect

    Majewski, J.; Smith, G.S.; Kuhl, T.L.; Israelachvili, J.N.; Gerstenberg, M.C.

    1997-04-17

    The density distribution of a lipid monolayer at the air-water interface mixed with varying amounts of lipid with poly(ethylene glycol)polymer headgroups (polymer-lipid or PEG-lipid) was measured using neutron reflectometry. The structure of the monolayer at the interface was greatly perturbed by the presence of the bulky polymer-lipid headgroups resulting in a large increase in the thickness of the headgroup region normal to the interface and a systematic roughening of the interface with increasing polymer-lipid content. These results show how bulky hydrophilic moieties cause significant deformations and out-of-place protrusions of phospholipid monolayers and presumably bilayers, vesicles and biological membranes. In terms of polymer physics, very short polymer chains tethered to the air-water interface follow scaling behavior with a mushroom to brush transition with increasing polymer grafting density. 34 refs., 9 figs., 1 tab.

  20. Application of photoassisted electrochemical detection to explosive-containing environmental samples.

    PubMed

    Marple, Ronita L; LaCourse, William R

    2005-10-15

    High-performance liquid chromatography (HPLC) with ultraviolet (UV) absorbance and photoassisted electrochemical detection (PAED) is applied to the determination of explosives in groundwater and soil samples. On-line, solid-phase extraction minimizes sample pretreatment, enabling direct analysis of groundwater samples and soil extracts. Soils are extracted using pressurized fluid extraction, which is compared to the Environmental Protection Agency (EPA) sonication method. Limits of detection for explosives in the matrixes of interest are equivalent or superior (i.e., <10 parts-per-trillion for HMX) to those achieved using the EPA method 8330. HPLC-UV-PAED is also shown here to be more broadly applicable, as it is capable of determining nitro compounds of interest (e.g., nitroglycerin) that have poor UV chromophores. Additional selectivity of amine-substituted nitroaromatic explosives is achieved by using a photochemical reactor with a 366-nm wavelength lamp. By coupling reversed-phase columns of different selectivities together, baseline resolution of all 14 standard explosives is demonstrated.

  1. An Unbiased Estimator of Gene Diversity with Improved Variance for Samples Containing Related and Inbred Individuals of any Ploidy.

    PubMed

    Harris, Alexandre M; DeGiorgio, Michael

    2017-02-09

    Gene diversity, or expected heterozygosity (H), is a common statistic for assessing genetic variation within populations. Estimation of this statistic decreases in accuracy and precision when individuals are related or inbred, due to increased dependence among allele copies in the sample. The original unbiased estimator of expected heterozygosity underestimates true population diversity in samples containing relatives, as it only accounts for sample size. More recently, a general unbiased estimator of expected heterozygosity was developed that explicitly accounts for related and inbred individuals in samples. Though unbiased, this estimator's variance is greater than that of the original estimator. To address this issue, we introduce a general unbiased estimator of gene diversity for samples containing related or inbred individuals, which employs the best linear unbiased estimator of allele frequencies, rather than the commonly used sample proportion. We examine the properties of this estimator, [Formula: see text] relative to alternative estimators using simulations and theoretical predictions, and show that it predominantly has the smallest mean squared error relative to others. Further, we empirically assess the performance of [Formula: see text] on a global human microsatellite dataset of 5795 individuals, from 267 populations, genotyped at 645 loci. Additionally, we show that the improved variance of [Formula: see text] leads to improved estimates of the population differentiation statistic, [Formula: see text] which employs measures of gene diversity within its calculation. Finally, we provide an R script, BestHet, to compute this estimator from genomic and pedigree data.

  2. An Unbiased Estimator of Gene Diversity with Improved Variance for Samples Containing Related and Inbred Individuals of any Ploidy

    PubMed Central

    Harris, Alexandre M.; DeGiorgio, Michael

    2016-01-01

    Gene diversity, or expected heterozygosity (H), is a common statistic for assessing genetic variation within populations. Estimation of this statistic decreases in accuracy and precision when individuals are related or inbred, due to increased dependence among allele copies in the sample. The original unbiased estimator of expected heterozygosity underestimates true population diversity in samples containing relatives, as it only accounts for sample size. More recently, a general unbiased estimator of expected heterozygosity was developed that explicitly accounts for related and inbred individuals in samples. Though unbiased, this estimator’s variance is greater than that of the original estimator. To address this issue, we introduce a general unbiased estimator of gene diversity for samples containing related or inbred individuals, which employs the best linear unbiased estimator of allele frequencies, rather than the commonly used sample proportion. We examine the properties of this estimator, H∼BLUE, relative to alternative estimators using simulations and theoretical predictions, and show that it predominantly has the smallest mean squared error relative to others. Further, we empirically assess the performance of H∼BLUE on a global human microsatellite dataset of 5795 individuals, from 267 populations, genotyped at 645 loci. Additionally, we show that the improved variance of H∼BLUE leads to improved estimates of the population differentiation statistic, FST, which employs measures of gene diversity within its calculation. Finally, we provide an R script, BestHet, to compute this estimator from genomic and pedigree data. PMID:28040781

  3. Air sampling of flame retardants based on the use of mixed-bed sorption tubes--a validation study.

    PubMed

    Lazarov, Borislav; Swinnen, Rudi; Spruyt, Maarten; Maes, Frederick; Van Campenhout, Karen; Goelen, Eddy; Covaci, Adrian; Stranger, Marianne

    2015-11-01

    An analytical methodology using automatic thermal desorption and gas chromatography mass spectrometry analysis was optimized and validated for simultaneous determination of a set of components from three different flame retardant chemical classes: polybrominated diphenyl ethers (PBDEs) (PBDE-28, PBDE-47, PBDE-66, PBDE-85, PBDE-99, PBDE-100), organophosphate flame retardants (PFRs) (tributyl phosphate, tripropyl phosphate, tris(2-chloroethyl)phosphate-, tris(1,3-dichloro-2-propyl) phosphate, tris(2-ethylhexyl) phosphate, triphenyl phosphate, tris(2-chloro-1-methylethyl) phosphate and tricresylphosphate), and "novel" brominated flame retardants (NBFRs) (pentabromotoluene, 2,3,4,5,6-pentabromoethylbenzene, (2,3-dibromopropyl) (2,4,6-tribromophenyl) ether, hexabromobenzene, and 2-ethylhexyl 2,3,4,5-tetrabromobenzoate) in air. The methodology is based on low volume active air sampling of gaseous and particulate air fractions on mixed-bed (polydimethylsiloxane (PDMS)/Tenax TA) sorption tubes. The optimized method provides recoveries >88%; a limit of detection in the range of 6-25 pg m(-3) for PBDEs, 6-171 pg m(-3) for PFRs, and 7-41 pg m(-3) for NBFRs; a linearity greater than 0.996; and a repeatability of less than 10% for all studied compounds. The optimized method was compared with a standard method using active air sampling on XAD-2 sorbent material, followed by liquid extraction. On the one hand, the PDMS/Tenax TA method shows comparable results at longer sampling time conditions (e.g., indoor air sampling, personal air sampling). On the other hand, at shorter sampling time conditions (e.g., sampling from emission test chambers), the optimized method detects up to three times higher concentrations and identifies more flame retardant compounds compared to the standard method based on XAD-2 loading.

  4. Emission of atmospheric pollutants out of Africa - Analysis of CARIBIC aircraft air samples

    NASA Astrophysics Data System (ADS)

    Thorenz, Ute R.; Baker, Angela K.; Schuck, Tanja; van Velthoven, Peter F. J.; Ziereis, Helmut; Brenninkmeijer, Carl A. M.

    2014-05-01

    Africa is the single largest continental source of biomass burning (BB) emissions. The burning African savannas and tropical forests are a source for a wide range of chemical species, which are important for global atmospheric chemistry, especially for the pristine Southern Hemisphere. Emitted compounds include carbon monoxide (CO), nitrogen oxides (NOx), hydrocarbons, oxygenated hydrocarbons and particles. Deep convection over Central Africa transports boundary layer emissions to the free troposphere making aircraft-based observations useful for investigation of surface emissions and examination of transport and chemistry processes over Africa The CARIBIC project (Civil Aircraft for the Regular Investigation of the Atmosphere Based on an Instrument Container, www.caribic-atmosphere.com part of IAGOS www.iagos.org) is a long term atmospheric measurement program using an instrument container deployed aboard a Lufthansa Airbus A340-600 for a monthly sequence of long-distance passenger flights. Besides the online measurements mixing ratios of greenhouse gases and a suite of C2-C8 non methane hydrocarbons (NMHCs) are measured from flask samples collected at cruise altitude. During northern hemispheric winter 2010/2011 CARIBIC flights took place from Frankfurt to Cape Town and Johannesburg in South Africa. Several BB tracers like methane, CO and various NMHCs were found to be elevated over tropical Africa. Using tracer-CO- and tracer-NOy-correlations emissions were characterized. The NMHC-CO correlations show monthly changing slopes, indicating a change in burned biomass, major fire stage, source region and/or other factors influencing NMHC emissions. To expand our analysis of emission sources a source region data filter was used, based on backward trajectories calculated along the flight tracks. Taking all CARIBIC samples into account having backward trajectories to the African boundary layer the dataset was enlarged from 77 to 168 samples. For both datasets tracer

  5. Silicone lymphadenopathy: presentation of a further case containing asteroid bodies on fine-needle cytology sample.

    PubMed

    Malzone, Maria Gabriella; Campanile, Anna Cipolletta; Gioioso, Antonella; Fucito, Alfredo; D'Aiuto, Giuseppe; Botti, Gerardo; Fulciniti, Franco

    2015-01-01

    Silicone lymphadenopathy is a recognized complication of breast augmentation. It is thought to occur when silicone droplets migrate from breast implants to lymph nodes. We report the cytologic findings in axillary and inguinal lymph node aspirate smears from a 35-year-old Italian woman, who came to our observation 10 years after bilateral cosmetic breast augmentation. A fine-needle cytology of the axillary lymph node showed extensive granulomatous inflammation, numerous histiocytes, and multinucleated giant cells containing star-shaped structures known as "asteroid bodies." The inguinal lymph node aspirate simply showed an aspecific reactive hyperplasia. No evidence of malignancy was present in any of the smears as well as in the excised axillary lymph node.

  6. Recommended Immunological Strategies to Screen for Botulinum Neurotoxin-Containing Samples

    PubMed Central

    Simon, Stéphanie; Fiebig, Uwe; Liu, Yvonne; Tierney, Rob; Dano, Julie; Worbs, Sylvia; Endermann, Tanja; Nevers, Marie-Claire; Volland, Hervé; Sesardic, Dorothea; Dorner, Martin B.

    2015-01-01

    Botulinum neurotoxins (BoNTs) cause the life-threatening neurological illness botulism in humans and animals and are divided into seven serotypes (BoNT/A–G), of which serotypes A, B, E, and F cause the disease in humans. BoNTs are classified as “category A” bioterrorism threat agents and are relevant in the context of the Biological Weapons Convention. An international proficiency test (PT) was conducted to evaluate detection, quantification and discrimination capabilities of 23 expert laboratories from the health, food and security areas. Here we describe three immunological strategies that proved to be successful for the detection and quantification of BoNT/A, B, and E considering the restricted sample volume (1 mL) distributed. To analyze the samples qualitatively and quantitatively, the first strategy was based on sensitive immunoenzymatic and immunochromatographic assays for fast qualitative and quantitative analyses. In the second approach, a bead-based suspension array was used for screening followed by conventional ELISA for quantification. In the third approach, an ELISA plate format assay was used for serotype specific immunodetection of BoNT-cleaved substrates, detecting the activity of the light chain, rather than the toxin protein. The results provide guidance for further steps in quality assurance and highlight problems to address in the future. PMID:26703727

  7. Recommended Immunological Strategies to Screen for Botulinum Neurotoxin-Containing Samples.

    PubMed

    Simon, Stéphanie; Fiebig, Uwe; Liu, Yvonne; Tierney, Rob; Dano, Julie; Worbs, Sylvia; Endermann, Tanja; Nevers, Marie-Claire; Volland, Hervé; Sesardic, Dorothea; Dorner, Martin B

    2015-11-26

    Botulinum neurotoxins (BoNTs) cause the life-threatening neurological illness botulism in humans and animals and are divided into seven serotypes (BoNT/A-G), of which serotypes A, B, E, and F cause the disease in humans. BoNTs are classified as "category A" bioterrorism threat agents and are relevant in the context of the Biological Weapons Convention. An international proficiency test (PT) was conducted to evaluate detection, quantification and discrimination capabilities of 23 expert laboratories from the health, food and security areas. Here we describe three immunological strategies that proved to be successful for the detection and quantification of BoNT/A, B, and E considering the restricted sample volume (1 mL) distributed. To analyze the samples qualitatively and quantitatively, the first strategy was based on sensitive immunoenzymatic and immunochromatographic assays for fast qualitative and quantitative analyses. In the second approach, a bead-based suspension array was used for screening followed by conventional ELISA for quantification. In the third approach, an ELISA plate format assay was used for serotype specific immunodetection of BoNT-cleaved substrates, detecting the activity of the light chain, rather than the toxin protein. The results provide guidance for further steps in quality assurance and highlight problems to address in the future.

  8. Emissions of industrial furnaces burning diesel fuel oils of various sulfur contents with NaCl - contained atmospheric air

    SciTech Connect

    Lin, C.Y.; Hsieh, M.J.

    1996-04-01

    A small furnace associated with an industrial automatic burner was employed in this study to investigate the influences of sulfur content of fuel oils burned with NaCl contained atmospheric air on the emission characteristics of marine or industrial power-plants. The sulfur contents of 0.3 wt% and 1.0 wt% were considered. Diesel fuel oil A which approximates ASTM No. 2 fuel oil was atomized by the inlet air added with NaCl of 1.5 ppm concentration and thereafter burned within the furnace. It was found that under this burning condition the CO, SO{sub 2}, and O{sub 2} emissions increased with the addition of sulfur in the fuel oil. However, the gas temperature and NO{sub x} concentration were affected by the increase of sulfur content to only a minor extent. 14 refs., 10 figs.

  9. Comparison of air dispersion modeling results with ambient air sampling data: A case study at Tacoma Landfill, a National Priorities List Site

    SciTech Connect

    Griffin, L.R. ); Rutherford, T.L. )

    1994-08-01

    Air dispersion modeling, ambient air sampling, and emissions testing of landfill sources have been performed to evaluate the effects of remedial activities on ambient air surrounding the Tacoma Landfill. In 1983, the Tacoma Landfill was placed on the National Priorities List (NPL) as part of the Commencement Bay/South Tacoma Channel Superfund site. Remedial activities completed, or near completion, at the 190 acre (768,903 m[sup 2]) Tacoma Landfill include a groundwater extraction system and air stripping units used to remove volatile organic compounds (VOCs) from groundwater, landfill gas extraction and flare system to control gas migration from the landfill, landfill liner and leachate collection system for an active section of the landfill, and a landfill cap that covers the inactive portions of the landfill. Dispersion modeling was performed with measured stack emission data using Industrial Source Complex (ISC) to determine the groundlevel concentrations of VOCs from the air stripper, flares, and active portion of the landfill for comparison with the measured ambient air data collected during 1992. 9 refs., 3 figs., 6 tabs.

  10. A novel Whole Air Sample Profiler (WASP) for the quantification of volatile organic compounds in the boundary layer

    SciTech Connect

    Mak, J. E.; Su, L.; Guenther, Alex B.; Karl, Thomas G.

    2013-10-16

    The emission and fate of reactive VOCs is of inherent interest to those studying chemical biosphere-atmosphere interactions. In-canopy VOC observations are obtainable using tower-based samplers, but the lack of suitable sampling systems for the full boundary 5 layer has limited the data characterizing the vertical structure of such gases above the canopy height and still in the boundary layer. This is the important region where many reactive VOCs are oxidized or otherwise removed. Here we describe an airborne sampling system designed to collect a vertical profile of air into a 3/800 OD tube 150m in length. The inlet ram air pressure is used to flow sampled air through the 10 tube, which results in a varying flow rate based on aircraft speed and altitude. Since aircraft velocity decreases during ascent, it is necessary to account for the variable flow rate into the tube. This is accomplished using a reference gas that is pulsed into the air stream so that the precise altitude of the collected air can be reconstructed post-collection. The pulsed injections are also used to determine any significant effect 15 from diffusion/mixing within the sampling tube, either during collection or subsequent extraction for gas analysis. This system has been successfully deployed, and we show some measured vertical profiles of isoprene and its oxidation products methacrolein and methyl vinyl ketone from a mixed canopy near Columbia, Missouri.

  11. A portable local exhaust hood system used to sample one-ton containers (TCs) previously filled with chemical warfare munitions

    SciTech Connect

    Butler, D.R.; McFeters, J.J.; Williams, L.D.

    1995-12-31

    Tennessee Valley Authority (TVA), Muscle Shoals, Alabama, by contract with the Department of the Army, Rocky Mountain Arsenal (RMA), Denver, Colorado, sampled and verified the decontamination level of 2,354 empty one-ton containers (TCs) previously used to store chemical warfare munitions. The TCs had previously been chemically and/or thermally decontaminated and were stored on RMA awaiting removal and disposal. The size and weight of the TCs prohibited placing them inside an enclosure during sampling. To enable sampling containers in place, a portable local exhaust hood was devised to protect sampling personnel and to prevent the release of any residual chemical agent vapors to the environment. Agent vapors captured by the hood were scrubbed through a 200-pound bed of activated charcoal before being released to the ambient environment. Engineers and work crews on-site in Denver conceived the hood design and tested three prototypes before obtaining a functional unit. Crafts persons in Muscle Shoals fabricated the hood designs and made modifications. Over a five-month period in the summer of 1990, TVA successfully sampled 2,354 TCs for four chemical agents with no personnel exposures and no release of agent into the environment. Residual contamination was identified in 547 TCs.

  12. Day and night variation in chemical composition and toxicological responses of size segregated urban air PM samples in a high air pollution situation

    NASA Astrophysics Data System (ADS)

    Jalava, P. I.; Wang, Q.; Kuuspalo, K.; Ruusunen, J.; Hao, L.; Fang, D.; Väisänen, O.; Ruuskanen, A.; Sippula, O.; Happo, M. S.; Uski, O.; Kasurinen, S.; Torvela, T.; Koponen, H.; Lehtinen, K. E. J.; Komppula, M.; Gu, C.; Jokiniemi, J.; Hirvonen, M.-R.

    2015-11-01

    Urban air particulate pollution is a known cause for adverse human health effects worldwide. China has encountered air quality problems in recent years due to rapid industrialization. Toxicological effects induced by particulate air pollution vary with particle sizes and season. However, it is not known how distinctively different photochemical activity and different emission sources during the day and the night affect the chemical composition of the PM size ranges and subsequently how it is reflected to the toxicological properties of the PM exposures. The particulate matter (PM) samples were collected in four different size ranges (PM10-2.5; PM2.5-1; PM1-0.2 and PM0.2) with a high volume cascade impactor. The PM samples were extracted with methanol, dried and thereafter used in the chemical and toxicological analyses. RAW264.7 macrophages were exposed to the particulate samples in four different doses for 24 h. Cytotoxicity, inflammatory parameters, cell cycle and genotoxicity were measured after exposure of the cells to particulate samples. Particles were characterized for their chemical composition, including ions, element and PAH compounds, and transmission electron microscopy (TEM) was used to take images of the PM samples. Chemical composition and the induced toxicological responses of the size segregated PM samples showed considerable size dependent differences as well as day to night variation. The PM10-2.5 and the PM0.2 samples had the highest inflammatory potency among the size ranges. Instead, almost all the PM samples were equally cytotoxic and only minor differences were seen in genotoxicity and cell cycle effects. Overall, the PM0.2 samples had the highest toxic potential among the different size ranges in many parameters. PAH compounds in the samples and were generally more abundant during the night than the day, indicating possible photo-oxidation of the PAH compounds due to solar radiation. This was reflected to different toxicity in the PM

  13. Comparative ruminal and total tract digestion of a finishing diet containing fresh vs air-dry steam-flaked corn.

    PubMed

    Zinn, R A; Barrajas, R

    1997-07-01

    Ten Holstein steers (465 +/- 6 kg) with cannulas in the rumen and proximal duodenum were used in a crossover design experiment to evaluate the influence of air-dry vs fresh steam-flaked corn on characteristics of ruminal and total tract digestion. The basal diet contained 77% steam-flaked corn (DM basis). Air-dry steam-flaked corn (SFC-AD) was obtained from a single batch that had been allowed to air-dry for 5 d before beginning the trial. Fresh steam-flaked corn (SFC-F) was produced daily Monday through Friday. Following production, the SFC-F was placed in air-tight polybags and stored at 4 degrees C until the time of feeding. There was little difference (P > .20) between SFC-AD and SFC-F with respect to site and extent of digestion of OM, starch, and fiber. Moreover, the two treatments did not differ (P > .20) in ruminal degradability of feed N. Apparent total tract N digestion was slightly greater (2.4%, P < .05) for SFC-F than for SFC-AD. Treatments did not affect ruminal pH (P > .20); however, VFA concentration of ruminal fluid tended to be greater (8.3%, P < .10) for SFC-F than for SFC-AD, indicating that the initial rate of fermentation may have been greater with SFC-F. Ruminal molar proportions of acetate were not affected by treatments (P > .20), but ruminal molar proportions of propionate tended to be greater (9.7%, P < .10) and molar proportions of butyrate tended to be less (10.0%, P < .10) for SFC-F than for SFC-AD. We conclude that the characteristics of digestion and the feeding value of steam-flaked corn is not altered by air drying before feeding.

  14. Formation-containment control of second-order multi-agent systems with only sampled position data

    NASA Astrophysics Data System (ADS)

    Zheng, Baojie; Mu, Xiaowu

    2016-11-01

    This paper studies the formation-containment control problem of second-order multi-agent systems with only sampled position data. It is assumed that there exist interactions among leaders and the leaders' neighbours are only leaders. Two different control protocols with only sampled position information are proposed for followers and leaders, respectively. By the algebraic graph theory and matrix theory, sufficient conditions are given to guarantee that the leaders achieve a desired formation and the followers asymptotically converge into the convex hull formed by the corresponding states of the leaders, i.e. the multi-agent systems achieve formation-containment. Moreover, an explicit expression of the formation position function is given for each leader. Finally, a numerical simulation is provided to illustrate the effectiveness of theoretical results.

  15. Tri (2-chloroisopropyl) phosphate--an unexpected organochlorine contaminant in some charcoal air-sampling sorbent tubes.

    PubMed

    van Netten, C; Brands, R; Park, J; Deverall, R

    1991-09-01

    Air sampling in a government building was necessary in response to reports of a cancer cluster. SKC (Eighty Four, Pa.) charcoal coconut shell-based sorbent tubes (226-01 lot 120) were recommended for this procedure. A recently purchased supply was present at the University of British Columbia and consequently was used for this particular study. Analysis of the front charcoal section showed the presence of a flame retardant, tri (2-chloroisopropyl) phosphate, which was confirmed by gas liquid chromatography (GLC) and mass spectrometry analysis. In an effort to identify the source of this fire retardant in the building, it became apparent from the analysis done on unknown field blanks that tri (2-chloroisopropyl) phosphate was a contaminant of the sorbent tubes used. Analysis of additional blank tubes identified the foam separators as the most likely source of contamination. Levels of tri (2-chloroisopropyl) phosphate in the front charcoal section ranged from 1.3 to 5.9 micrograms. The foam separator contained between 11.4 and 16.5 micrograms, and the backup charcoal section contained between 14.5 and 24.0 micrograms of tri (2-chloroisopropyl) phosphate. In addition, another flame retardant, tri (1,3 dichloro-2-propyl) phosphate was also found. Because these contaminants have long column retention times in GLC, it may not be apparent that these contaminants are present and consequently are likely to have modified the sorbent characteristics of the activated charcoal. Another batch of sorbent tubes bearing the same catalog number and lot number was purchased from the supplier; no flame retardants were found in this batch.(ABSTRACT TRUNCATED AT 250 WORDS)

  16. Tri (2-chloroisopropyl) phosphate--an unexpected organochlorine contaminant in some charcoal air-sampling sorbent tubes

    SciTech Connect

    van Netten, C.; Brands, R.; Park, J.; Deverall, R. )

    1991-09-01

    Air sampling in a government building was necessary in response to reports of a cancer cluster. SKC (Eighty Four, Pa.) charcoal coconut shell-based sorbent tubes (226-01 lot 120) were recommended for this procedure. A recently purchased supply was present at the University of British Columbia and consequently was used for this particular study. Analysis of the front charcoal section showed the presence of a flame retardant, tri (2-chloroisopropyl) phosphate, which was confirmed by gas liquid chromatography (GLC) and mass spectrometry analysis. In an effort to identify the source of this fire retardant in the building, it became apparent from the analysis done on unknown field blanks that tri (2-chloroisopropyl) phosphate was a contaminant of the sorbent tubes used. Analysis of additional blank tubes identified the foam separators as the most likely source of contamination. Levels of tri (2-chloroisopropyl) phosphate in the front charcoal section ranged from 1.3 to 5.9 micrograms. The foam separator contained between 11.4 and 16.5 micrograms, and the backup charcoal section contained between 14.5 and 24.0 micrograms of tri (2-chloroisopropyl) phosphate. In addition, another flame retardant, tri (1,3 dichloro-2-propyl) phosphate was also found. Because these contaminants have long column retention times in GLC, it may not be apparent that these contaminants are present and consequently are likely to have modified the sorbent characteristics of the activated charcoal. Another batch of sorbent tubes bearing the same catalog number and lot number was purchased from the supplier; no flame retardants were found in this batch.

  17. Minimization of sample volume with air-segmented sample injection and the simultaneous determination of trace elements by ICP-MS.

    PubMed

    Noguchi, Osamu; Oshima, Mitsuko; Motomizu, Shoji

    2008-05-01

    The application of inductively coupled plasma mass spectrometry (ICP-MS) to forensic chemistry was studied. The developed method, air-segmented sample injection (ASSI) coupled with ICP-MS, allowed the determination of about 25 elements at the sub-ppb level with only 0.2 ml of a sample solution. The optimum sample flow rate was found to be 0.4 ml min(-1), along with a sample suction time of 30 s. The proposed method was validated by determining trace elements in river-water certified reference material (SLRS-4) issued by National Research Council Canada. The analytical results of the proposed method were in good agreement with the certified values. This method was successfully applied to a human hair sample, the volume of which was 3 ml.

  18. Suitability of air sampling locations downstream of bends and static mixing elements.

    PubMed

    McFarland, A R; Gupta, R; Anand, N K

    1999-12-01

    The revised standard for sampling effluent air from stacks and ducts of the nuclear industry places limits on the non-uniformity of velocity and contaminant profiles at the sampling location; namely, the coefficients of variation must not exceed 20% over an area that encompasses at least the center 2/3 of the cross sectional area. Tests were conducted to characterize the degree of mixing at downstream locations as affected by several types of flow disturbances, including 90 degree elbows and commercial static mixing devices. Flow straighteners were incorporated into the ducting upstream of the mixer to be tested to simulate the dampening of flow turbulence that might occur because of upstream HEPA filters. The coefficients of variation of velocity and tracer gas concentration measured in a straight tube at a distance of 3 diameters downstream from a 90 degree elbow were 17% and 69%, respectively. The mixing is impacted by the upstream flow turbulence. Without a flow straightener, the tracer gas concentration coefficient of variation was reduced to 33% at the 3-diameter location. The use of static mixing elements can greatly enhance the mixing process. A ring placed just downstream of a 90 degree elbow, which blocks the outer 56% of the cross sectional area, results in a coefficient of variation of 19% for tracer gas concentration at the 3-diameter location. Pressure loss across the elbow with the ring is about nine times that of the basic elbow. One of the commercially available static mixers provides coefficients of variation that are less than 10% for both velocity and tracer gas concentration at 4 diameters downstream from the mixer with a pressure loss that is only about 3.5 times as large as that of a 90 degree elbow.

  19. Ice nucleation active particles in continental air samples over Mainz, Germany

    NASA Astrophysics Data System (ADS)

    Pummer, Bernhard G.; Pöschl, Ulrich; Fröhlich-Nowoisky, Janine

    2016-04-01

    Aerosol particles are of central importance for atmospheric chemistry and physics, climate and public health. Some of these particles possess ice nucleation activity (INA), which is highly relevant for cloud formation and precipitation. In 2010, air filter samples were collected with a high-volume filter sampler separating fine and coarse particles (aerodynamic cut-off diameter 3 μm) in Mainz, Germany. In this study, the INA of the atmospheric particles deposited on these filters was determined. Therefore,they were extracted with ultrapure water, which was then measured in a droplet freezing assay, as described in Fröhlich-Nowoisky et al. (2015). The determined concentration of ice nucleators (INs) was between 0.3 and 2per m³ at 266 K, and between5 and 75 per m³ at 260 K. The INs were further characterized by different treatments, like heating (308 K, 371 K), filtration (0.1 μm, 300 kDa), and digestion with papain (10 mg/ml). We further investigated, which atmospheric conditions (e.g. weather) and distinguished events (e.g. dust storms, volcanic eruptions, and pollen peaks) influenced the number and nature of these INs. Fröhlich-Nowoisky, J., Hill, T. C. J., Pummer, B. G., Yordanova, P., Franc, G. D., and Pöschl, U.: Ice nucleation activity in the widespread soil fungus Mortierella alpina, Biogeosci., 12, 1057-1071, doi:10.5194/bg-12-1057-2015, 2015.

  20. Comparison of halocarbon measurements in an atmospheric dry whole air sample

    PubMed Central

    Hall, Bradley D.; Harth, Christina M.; Kim, Jin Seog; Lee, Jeongsoon; Montzka, Stephen A.; Mühle, Jens; Reimann, Stefan; Vollmer, Martin K.; Weiss, Ray F.

    2015-01-01

    The growing awareness of climate change/global warming, and continuing concerns regarding stratospheric ozone depletion, will require continued measurements and standards for many compounds, in particular halocarbons that are linked to these issues. In order to track atmospheric mole fractions and assess the impact of policy on emission rates, it is necessary to demonstrate measurement equivalence at the highest levels of accuracy for assigned values of standards. Precise measurements of these species aid in determining small changes in their atmospheric abundance. A common source of standards/scales and/or well-documented agreement of different scales used to calibrate the measurement instrumentation are key to understanding many sets of data reported by researchers. This report describes the results of a comparison study among National Metrology Institutes and atmospheric research laboratories for the chlorofluorocarbons (CFCs) dichlorodifluoromethane (CFC-12), trichlorofluoromethane (CFC-11), and 1,1,2-trichlorotrifluoroethane (CFC-113); the hydrochlorofluorocarbons (HCFCs) chlorodifluoromethane (HCFC-22) and 1-chloro-1,1-difluoroethane (HCFC-142b); and the hydrofluorocarbon (HFC) 1,1,1,2-tetrafluoroethane (HFC-134a), all in a dried whole air sample. The objective of this study is to compare calibration standards/scales and the measurement capabilities of the participants for these halocarbons at trace atmospheric levels. The results of this study show agreement among four independent calibration scales to better than 2.5% in almost all cases, with many of the reported agreements being better than 1.0%. PMID:26753167

  1. Time-resolvable fluorescent conjugates for the detection of pathogens in environmental samples containing autofluorescent material

    NASA Astrophysics Data System (ADS)

    Connally, Russell; Veal, Duncan; Piper, James A.

    2003-07-01

    Water is routinely monitored for environmental pathogens such a Cryptosporidium and Giardia using immunofluorescence microscopy (IFM). Autofluorescence can greatly diminish an operators capacity to resolve labeled pathogens from non-specific background. Naturally fluorescing components (autofluorophores) encountered in biological samples typically have fluorescent lifetimes (τ) of less than 100 nanoseconds and their emissions may be excluded through use of time-resolved fluorescence microscopy (TRFM). TRFM relies on the large differences in τ between autofluorescent molecules and long-lived lanthanide chelates. In TRFM, targets labeled with a time-resolvable fluorescent immunoconjugate are excited by an intense (UV) light pulse. A short delay is imposed to permit the decay of autofluorescence before capture of luminescence from the excited chelate using an image intensified CCD camera. In our experience, autofluorescence can be reduced to insignificant levels with a consequent 30-fold increase in target visibility using TRFM techniques. We report conjugation of a novel europium chelate to a monoclonal antibody specific for Giardia lamblia and use of the immunoconjugate for TRFM studies. Initial attempts to conjugate the same chelate to a monoclonal antibody directed against Cryptosporidium parvum led to poorly fluorescent constructs that were prone to denature and precipitate. We successfully conjugated BHHCT to anti-mouse polyvalent immunoglobulin and used this construct to overcome the difficulties in direct labeling of the anti-Cryptosporidium antibody. Both Giardia and Cryptosporidium were labeled using the anti-mouse protocol with a subsequent 20-fold and 6.6-fold suppression of autofluorescence respectively. A rapid protocol for conjugating and purifying the immunoconjugate was found and methods of quantifying the fluorescence to protein ratio determined. Performance of our TRFM was dependent on the quality and brightness of the immunoconjugate and

  2. Comparison of Air Impaction and Electrostatic Dust Collector Sampling Methods to Assess Airborne Fungal Contamination in Public Buildings.

    PubMed

    Normand, Anne-Cécile; Ranque, Stéphane; Cassagne, Carole; Gaudart, Jean; Sallah, Kankoé; Charpin, Denis-André; Piarroux, Renaud

    2016-03-01

    Many ailments can be linked to exposure to indoor airborne fungus. However, obtaining a precise measurement of airborne fungal levels is complicated partly due to indoor air fluctuations and non-standardized techniques. Electrostatic dust collector (EDC) sampling devices have been used to measure a wide range of airborne analytes, including endotoxins, allergens, β-glucans, and microbial DNA in various indoor environments. In contrast, viable mold contamination has only been assessed in highly contaminated environments such as farms and archive buildings. This study aimed to assess the use of EDCs, compared with repeated air-impactor measurements, to assess airborne viable fungal flora in moderately contaminated indoor environments. Indoor airborne fungal flora was cultured from EDCs and daily air-impaction samples collected in an office building and a daycare center. The quantitative fungal measurements obtained using a single EDC significantly correlated with the cumulative measurement of nine daily air impactions. Both methods enabled the assessment of fungal exposure, although a few differences were observed between the detected fungal species and the relative quantity of each species. EDCs were also used over a 32-month period to monitor indoor airborne fungal flora in a hospital office building, which enabled us to assess the impact of outdoor events (e.g. ground excavations) on the fungal flora levels on the indoor environment. In conclusion, EDC-based measurements provided a relatively accurate profile of the viable airborne flora present during a sampling period. In particular, EDCs provided a more representative assessment of fungal levels compared with single air-impactor sampling. The EDC technique is also simpler than performing repetitive air-impaction measures over the course of several consecutive days. EDC is a versatile tool for collecting airborne samples and was efficient for measuring mold levels in indoor environments.

  3. Estimating sampling biases and measurement uncertainties of AIRS/AMSU-A temperature and water vapor observations using MERRA reanalysis

    NASA Astrophysics Data System (ADS)

    Hearty, Thomas J.; Savtchenko, Andrey; Tian, Baijun; Fetzer, Eric; Yung, Yuk L.; Theobald, Michael; Vollmer, Bruce; Fishbein, Evan; Won, Young-In

    2014-03-01

    We use MERRA (Modern Era Retrospective-Analysis for Research Applications) temperature and water vapor data to estimate the sampling biases of climatologies derived from the AIRS/AMSU-A (Atmospheric Infrared Sounder/Advanced Microwave Sounding Unit-A) suite of instruments. We separate the total sampling bias into temporal and instrumental components. The temporal component is caused by the AIRS/AMSU-A orbit and swath that are not able to sample all of time and space. The instrumental component is caused by scenes that prevent successful retrievals. The temporal sampling biases are generally smaller than the instrumental sampling biases except in regions with large diurnal variations, such as the boundary layer, where the temporal sampling biases of temperature can be ± 2 K and water vapor can be 10% wet. The instrumental sampling biases are the main contributor to the total sampling biases and are mainly caused by clouds. They are up to 2 K cold and > 30% dry over midlatitude storm tracks and tropical deep convective cloudy regions and up to 20% wet over stratus regions. However, other factors such as surface emissivity and temperature can also influence the instrumental sampling bias over deserts where the biases can be up to 1 K cold and 10% wet. Some instrumental sampling biases can vary seasonally and/or diurnally. We also estimate the combined measurement uncertainties of temperature and water vapor from AIRS/AMSU-A and MERRA by comparing similarly sampled climatologies from both data sets. The measurement differences are often larger than the sampling biases and have longitudinal variations.

  4. Estimating Sampling Biases and Measurement Uncertainties of AIRS-AMSU-A Temperature and Water Vapor Observations Using MERRA Reanalysis

    NASA Technical Reports Server (NTRS)

    Hearty, Thomas J.; Savtchenko, Andrey K.; Tian, Baijun; Fetzer, Eric; Yung, Yuk L.; Theobald, Michael; Vollmer, Bruce; Fishbein, Evan; Won, Young-In

    2014-01-01

    We use MERRA (Modern Era Retrospective-Analysis for Research Applications) temperature and water vapor data to estimate the sampling biases of climatologies derived from the AIRS/AMSU-A (Atmospheric Infrared Sounder/Advanced Microwave Sounding Unit-A) suite of instruments. We separate the total sampling bias into temporal and instrumental components. The temporal component is caused by the AIRS/AMSU-A orbit and swath that are not able to sample all of time and space. The instrumental component is caused by scenes that prevent successful retrievals. The temporal sampling biases are generally smaller than the instrumental sampling biases except in regions with large diurnal variations, such as the boundary layer, where the temporal sampling biases of temperature can be +/- 2 K and water vapor can be 10% wet. The instrumental sampling biases are the main contributor to the total sampling biases and are mainly caused by clouds. They are up to 2 K cold and greater than 30% dry over mid-latitude storm tracks and tropical deep convective cloudy regions and up to 20% wet over stratus regions. However, other factors such as surface emissivity and temperature can also influence the instrumental sampling bias over deserts where the biases can be up to 1 K cold and 10% wet. Some instrumental sampling biases can vary seasonally and/or diurnally. We also estimate the combined measurement uncertainties of temperature and water vapor from AIRS/AMSU-A and MERRA by comparing similarly sampled climatologies from both data sets. The measurement differences are often larger than the sampling biases and have longitudinal variations.

  5. Sampled-data-based consensus and containment control of multiple harmonic oscillators: A motion-planning approach

    NASA Astrophysics Data System (ADS)

    Liu, Yongfang; Zhao, Yu; Chen, Guanrong

    2016-11-01

    This paper studies the distributed consensus and containment problems for a group of harmonic oscillators with a directed communication topology. First, for consensus without a leader, a class of distributed consensus protocols is designed by using motion planning and Pontryagin's principle. The proposed protocol only requires relative information measurements at the sampling instants, without requiring information exchange over the sampled interval. By using stability theory and the properties of stochastic matrices, it is proved that the distributed consensus problem can be solved in the motion planning framework. Second, for the case with multiple leaders, a class of distributed containment protocols is developed for followers such that their positions and velocities can ultimately converge to the convex hull formed by those of the leaders. Compared with the existing consensus algorithms, a remarkable advantage of the proposed sampled-data-based protocols is that the sampling periods, communication topologies and control gains are all decoupled and can be separately designed, which relaxes many restrictions in controllers design. Finally, some numerical examples are given to illustrate the effectiveness of the analytical results.

  6. Sampled-data-based consensus and containment control of multiple harmonic oscillators: A motion-planning approach.

    PubMed

    Liu, Yongfang; Zhao, Yu; Chen, Guanrong

    2016-11-01

    This paper studies the distributed consensus and containment problems for a group of harmonic oscillators with a directed communication topology. First, for consensus without a leader, a class of distributed consensus protocols is designed by using motion planning and Pontryagin's principle. The proposed protocol only requires relative information measurements at the sampling instants, without requiring information exchange over the sampled interval. By using stability theory and the properties of stochastic matrices, it is proved that the distributed consensus problem can be solved in the motion planning framework. Second, for the case with multiple leaders, a class of distributed containment protocols is developed for followers such that their positions and velocities can ultimately converge to the convex hull formed by those of the leaders. Compared with the existing consensus algorithms, a remarkable advantage of the proposed sampled-data-based protocols is that the sampling periods, communication topologies and control gains are all decoupled and can be separately designed, which relaxes many restrictions in controllers design. Finally, some numerical examples are given to illustrate the effectiveness of the analytical results.

  7. US EPA Base Study Standard Operating Procedure for Sampling and Characterization of Viable and Non-Viable Bioaerosols in Indoor Air

    EPA Pesticide Factsheets

    The objective of the procedure is to collect a representative sample concentration of total airborne fungal spores (viable and non-viable) that may be present in indoor air and in the outdoor air supplied to the space tested.

  8. Fully Self-Contained Vision-Aided Navigation and Landing of a Micro Air Vehicle Independent from External Sensor Inputs

    NASA Technical Reports Server (NTRS)

    Brockers, Roland; Susca, Sara; Zhu, David; Matthies, Larry

    2012-01-01

    Direct-lift micro air vehicles have important applications in reconnaissance. In order to conduct persistent surveillance in urban environments, it is essential that these systems can perform autonomous landing maneuvers on elevated surfaces that provide high vantage points without the help of any external sensor and with a fully contained on-board software solution. In this paper, we present a micro air vehicle that uses vision feedback from a single down looking camera to navigate autonomously and detect an elevated landing platform as a surrogate for a roof top. Our method requires no special preparation (labels or markers) of the landing location. Rather, leveraging the planar character of urban structure, the landing platform detection system uses a planar homography decomposition to detect landing targets and produce approach waypoints for autonomous landing. The vehicle control algorithm uses a Kalman filter based approach for pose estimation to fuse visual SLAM (PTAM) position estimates with IMU data to correct for high latency SLAM inputs and to increase the position estimate update rate in order to improve control stability. Scale recovery is achieved using inputs from a sonar altimeter. In experimental runs, we demonstrate a real-time implementation running on-board a micro aerial vehicle that is fully self-contained and independent from any external sensor information. With this method, the vehicle is able to search autonomously for a landing location and perform precision landing maneuvers on the detected targets.

  9. A passive sampling-based analytical strategy for the determination of volatile organic compounds in the air of working areas.

    PubMed

    Ly-Verdú, Saray; Esteve-Turrillas, Francesc A; Pastor, Agustín; de la Guardia, Miguel

    2010-09-16

    An analytical methodology based on the use of a polyethylene layflat tube filled with activated carbon and Florisil (ACFL-VERAM) was employed for the passive sampling of volatile organic compounds (VOCs) in the air of working areas of packing industries. VOCs amount in the ACFL-VERAM sampler was directly determined through head-space-gas chromatography-mass spectrometry (HS-GC-MS) allowing a direct determination in only 20 min without the need of any previous treatment. Uptake parameters, like sampling rate (R(S)) and sampler-air partition coefficient (K(SA)), were determined for every studied VOC from adsorption isotherm data. Additionally, experimental equations have been proposed to predict R(S) and K(SA) from the octanol-air partition coefficients reported in the literature. The proposed methodology reaches method detection levels from 0.007 to 0.2 mg m(-3) for the studied VOCs.

  10. Comparison of Lichen, Conifer Needles, Passive Air Sampling Devices, and Snowpack as Passive Sampling Media to Measure Semi-Volatile Organic Compounds in Remote Atmospheres

    PubMed Central

    SCHRLAU, JILL E.; GEISER, LINDA; HAGEMAN, KIMBERLY J.; LANDERS, DIXON H.

    2011-01-01

    A wide range of semi-volatile organic compounds (SOCs), including pesticides and polycyclic aromatic hydrocarbons (PAHs), were measured in lichen, conifer needles, snowpack and XAD-based passive air sampling devices (PASDs) collected from 19 different U.S. national parks in order to compare the magnitude and mechanism of SOC accumulation in the different passive sampling media. Lichen accumulated the highest SOC concentrations, in part because of its long (and unknown) exposure period, while PASDs accumulated the lowest concentrations. However, only the PASD SOC concentrations can be used to calculate an average atmospheric gas-phase SOC concentration because the sampling rates are known and the media is uniform. Only the lichen and snowpack SOC accumulation profiles were statistically significantly correlated (r = 0.552, p-value <0.0001) because they both accumulate SOCs present in the atmospheric particle-phase. This suggests that needles and PASDs represent a different composition of the atmosphere than lichen and snowpack and that the interpretation of atmospheric SOC composition is dependent on the type of passive sampling media used. All four passive sampling media preferentially accumulated SOCs with relatively low air-water partition coefficients, while snowpack accumulated SOCs with higher log KOA values compared to the other media. Lichen accumulated more SOCs with log KOA > 10 relative to needles and showed a greater accumulation of particle-phase PAHs. PMID:22087860

  11. Comparison of lichen, conifer needles, passive air sampling devices, and snowpack as passive sampling media to measure semi-volatile organic compounds in remote atmospheres.

    PubMed

    Schrlau, Jill E; Geiser, Linda; Hageman, Kimberly J; Landers, Dixon H; Simonich, Staci Massey

    2011-12-15

    A wide range of semivolatile organic compounds (SOCs), including pesticides and polycyclic aromatic hydrocarbons (PAHs), were measured in lichen, conifer needles, snowpack and XAD-based passive air sampling devices (PASDs) collected from 19 different U.S. national parks in order to compare the magnitude and mechanism of SOC accumulation in the different passive sampling media. Lichen accumulated the highest SOC concentrations, in part because of its long (and unknown) exposure period, whereas PASDs accumulated the lowest concentrations. However, only the PASD SOC concentrations can be used to calculate an average atmospheric gas-phase SOC concentration because the sampling rates are known and the media is uniform. Only the lichen and snowpack SOC accumulation profiles were statistically significantly correlated (r = 0.552, p-value <0.0001) because they both accumulate SOCs present in the atmospheric particle-phase. This suggests that needles and PASDs represent a different composition of the atmosphere than lichen and snowpack and that the interpretation of atmospheric SOC composition is dependent on the type of passive sampling media used. All four passive sampling media preferentially accumulated SOCs with relatively low air-water partition coefficients, while snowpack accumulated SOCs with higher log K(OA) values compared to the other media. Lichen accumulated more SOCs with log K(OA) > 10 relative to needles and showed a greater accumulation of particle-phase PAHs.

  12. 3D Air Quality and the Clean Air Interstate Rule: Lagrangian Sampling of CMAQ Model Results to Aid Regional Accountability Metrics

    NASA Technical Reports Server (NTRS)

    Fairlie, T. D.; Szykman, Jim; Pierce, Robert B.; Gilliland, A. B.; Engel-Cox, Jill; Weber, Stephanie; Kittaka, Chieko; Al-Saadi, Jassim A.; Scheffe, Rich; Dimmick, Fred; Tikvart, Joe

    2008-01-01

    The Clean Air Interstate Rule (CAIR) is expected to reduce transport of air pollutants (e.g. fine sulfate particles) in nonattainment areas in the Eastern United States. CAIR highlights the need for an integrated air quality observational and modeling system to understand sulfate as it moves in multiple dimensions, both spatially and temporally. Here, we demonstrate how results from an air quality model can be combined with a 3d monitoring network to provide decision makers with a tool to help quantify the impact of CAIR reductions in SO2 emissions on regional transport contributions to sulfate concentrations at surface monitors in the Baltimore, MD area, and help improve decision making for strategic implementation plans (SIPs). We sample results from the Community Multiscale Air Quality (CMAQ) model using ensemble back trajectories computed with the NASA Langley Research Center trajectory model to provide Lagrangian time series and vertical profile information, that can be compared with NASA satellite (MODIS), EPA surface, and lidar measurements. Results are used to assess the regional transport contribution to surface SO4 measurements in the Baltimore MSA, and to characterize the dominant source regions for low, medium, and high SO4 episodes.

  13. 32 CFR 806.27 - Samples of Air Force FOIA processing documents.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... documents. (a) This section includes suggested language in paragraph format that tracks Air Force and DoD FOIA guidance. The rest of the body of letters and memorandums should comply with Air Force... section, language in parentheses is for explanatory purposes only. Do not include any of the...

  14. It's Alive!: Students Observe Air-Water Interface Samples Rich with Organisms

    ERIC Educational Resources Information Center

    Avant, Thomas

    2002-01-01

    This article describes an experiment, designed by Cindy Henk, manager of the Socolofsky Microscopy Center at Louisiana State University (LSU), that involved collecting and viewing microorganisms in the air-water interface. The experiment was participated by Leesville High School microbiology students. The students found that the air-water…

  15. Treatment of desizing wastewater containing poly(vinyl alcohol) by wet air oxidation

    SciTech Connect

    Chen, G.; Lei, L.; Yue, P.L.; Cen, P.

    2000-05-01

    The effectiveness of wet air oxidation (WAO) is studied in a 2-L autoclave for the treatment of desizing wastewater from man-made fiber textile plants. At an oxygen pressure of less than 2 MPa, over 30-min, chemical oxygen demand (COD) removal was found to increase from 15 to 65% when the temperature was raised from 150 to 250 C. The biodegradability of the wastewater was also simultaneously increased. Up to 90% of the COD could be removed within 120 min. A simplified reaction mechanism is proposed which involves a direct mineralization step in parallel with a step in which an intermediate is formed prior to mineralization. A kinetic model for COD removal was developed based on this reaction mechanism. The model was tested with experimental COD results over the temperature range of the experiments. The dependence of the specific reaction rate constants was found to follow the Arrhenius type of equation. The direct oxidation of poly(vinyl alcohol) (PVA) to carbon dioxide and water is the dominant reaction step. The intermediates formed are not likely to be the acetic acid but may be short segments of PVA that are easily oxidized.

  16. Suppression of methane/air explosion by ultrafine water mist containing sodium chloride additive.

    PubMed

    Cao, Xingyan; Ren, Jingjie; Zhou, Yihui; Wang, Qiuju; Gao, Xuliang; Bi, Mingshu

    2015-03-21

    The suppression effect of ultrafine mists on methane/air explosions with methane concentrations of 6.5%, 8%, 9.5%, 11%, and 13.5% were experimentally studied in a closed visual vessel. Ultrafine water/NaCl solution mist as well as pure water mist was adopted and the droplet sizes of mists were measured by phase doppler particle analyzer (PDPA). A high speed camera was used to record the flame evolution processes. In contrast to pure water mist, the flame propagation speed, the maximum explosion overpressure (ΔP(max)), and the maximum pressure rising rate ((dP/dt)max) decreased significantly, with the "tulip" flame disappearing and the flame getting brighter. The results show that the suppressing effect on methane explosion by ultrafine water/NaCl solution mist is influenced by the mist amount and methane concentration. With the increase of the mist amount, the pressure, and the flame speed both descended significantly. And when the mist amount reached 74.08 g/m(3) and 37.04 g/m(3), the flames of 6.5% and 13.5% methane explosions can be absolutely suppressed, respectively. All of results indicate that addition of NaCl can improve the suppression effect of ultrafine pure water mist on the methane explosions, and the suppression effect is considered due to the combination effect of physical and chemical inhibitions.

  17. Evolution of the Lunar Receiving Laboratory to the Astromaterial Sample Curation Facility: Technical Tensions Between Containment and Cleanliness, Between Particulate and Organic Cleanliness

    NASA Technical Reports Server (NTRS)

    Allton, J. H.; Zeigler, R. A.; Calaway, M. J.

    2016-01-01

    The Lunar Receiving Laboratory (LRL) was planned and constructed in the 1960s to support the Apollo program in the context of landing on the Moon and safely returning humans. The enduring science return from that effort is a result of careful curation of planetary materials. Technical decisions for the first facility included sample handling environment (vacuum vs inert gas), and instruments for making basic sample assessment, but the most difficult decision, and most visible, was stringent biosafety vs ultra-clean sample handling. Biosafety required handling of samples in negative pressure gloveboxes and rooms for containment and use of sterilizing protocols and animal/plant models for hazard assessment. Ultra-clean sample handling worked best in positive pressure nitrogen environment gloveboxes in positive pressure rooms, using cleanable tools of tightly controlled composition. The requirements for these two objectives were so different, that the solution was to design and build a new facility for specific purpose of preserving the scientific integrity of the samples. The resulting Lunar Curatorial Facility was designed and constructed, from 1972-1979, with advice and oversight by a very active committee comprised of lunar sample scientists. The high precision analyses required for planetary science are enabled by stringent contamination control of trace elements in the materials and protocols of construction (e.g., trace element screening for paint and flooring materials) and the equipment used in sample handling and storage. As other astromaterials, especially small particles and atoms, were added to the collections curated, the technical tension between particulate cleanliness and organic cleanliness was addressed in more detail. Techniques for minimizing particulate contamination in sample handling environments use high efficiency air filtering techniques typically requiring organic sealants which offgas. Protocols for reducing adventitious carbon on sample

  18. Early detection of foot-and-mouth disease virus from infected cattle using a dry filter air sampling system

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Foot-and-mouth disease (FMD) is a highly contagious livestock disease of high economic impact. Early detection of FMD virus (FMDV) is fundamental for rapid outbreak control. Air sampling collection has been demonstrated as a useful technique for detection of FMDV RNA in infected animals, related to ...

  19. Caution on the use of Viton® or FETFE® O-rings in carbon dioxide sample containers for δ180 analysis

    USGS Publications Warehouse

    Revesz, Kinga M.; Coplen, Tyler B.

    1991-01-01

    Caution needs to be exercised in selecting sample containers for CO2 isotope-ratio samples of < 200 μmol. If stopcocks are used in construction of containers for such samples, the use of all-glass stopcocks with Apiezon N® hydrocarbon-based grease will eliminate the fractionation of oxygen isotopes.

  20. Analysis of formaldehyde and acrolein in the aqueous samples using a novel needle trap device containing nanoporous silica aerogel sorbent.

    PubMed

    Barkhordari, Abdullah; Azari, Mansour R; Zendehdel, Rezvan; Heidari, Mahmoud

    2017-04-01

    In this research, a needle trap device (NTD) packed with nanoporous silica aerogel as a sorbent was used as a new technique for sampling and analysis of formaldehyde and acrolein compounds in aqueous and urine samples. The obtained results were compared with those of the commercial sorbent Carboxen1000. Active sampling was used and a 21-G needle was applied for extraction of gas in the sample headspace. The optimization of experimental parameters like salt addition, temperature and desorption time was done and the performance of the NTD for the extraction of the compounds was evaluated. The optimum temperature and time of desorption were 280 °C and 2 min, respectively. The ranges of limit of detection, limit of quantification and relative standard deviation (RSD) were 0.01-0.03 μg L(-1), 0.03-0.1 μg L(-1) and 2.8-7.3%, respectively. It was found that the NTD containing nanoporous silica aerogel had a better performance. Thus, this technique can be applied as an effective and reliable method for sampling and analysis of aldehyde compounds from different biological matrices like urine, exhalation and so on.

  1. Stability of 11 prevalent synthetic cannabinoids in authentic neat oral fluid samples: glass versus polypropylene containers at different temperatures.

    PubMed

    Kneisel, Stefan; Speck, Michael; Moosmann, Bjoern; Auwärter, Volker

    2013-07-01

    Although synthetic cannabinoids have been intensively investigated in recent years and oral fluid testing is becoming increasingly popular in suspected driving under the influence of drugs cases, only scarce data on their stability in authentic neat oral fluid (nOF) samples are yet available. However, especially for these new psychoactive drugs, investigations focusing on stability issues are necessary as inappropriate storage conditions may lead to considerable analytical problems. Since it has been shown for Δ(9) -tetrahydrocannabinol that adsorption to plastic surfaces may lead to considerable drug loss, we aimed to evaluate whether adsorption also has to be taken into account for synthetic cannabinoids in nOF samples. In this paper, the results of investigations on the recovery of 11 prevalent synthetic cannabinoids from authentic nOF samples stored over 72 h in RapidEASE (high quality borosilicate glass) and Sciteck Saliva Split Collector (polypropylene) tubes at 4 and 25 °C are presented. Our findings clearly demonstrate that lipophilic synthetic cannabinoids present in nOF samples adsorb to the surface of polypropylene containers when stored at room temperature, leading to considerable drug loss. Hence, when using polypropylene tubes, samples should be shipped cooled in order to avoid a substantial decrease of the analyte concentration during transportation.

  2. Use of depuration compounds in passive air samplers: results from active sampling-supported field deployment, potential uses, and recommendations.

    PubMed

    Moeckel, Claudia; Harner, Tom; Nizzetto, Luca; Strandberg, Bo; Lindroth, Anders; Jones, Kevin C

    2009-05-01

    Depuration compounds (DCs) are added to passive air samplers (PAS) prior to deployment to account for the wind-dependency of the sampling rate for gas-phase compounds. This correction is particularly useful for providing comparable data for samplers that are deployed in different environments and subject to different meteorological conditions such as wind speeds. Two types of PAS--the polyurethane foam (PUF) disk sampler and semipermeable membrane devices (SPMDs)--were deployed at eight heights on a 100 m tower to test whether the DC approach could yield air concentrations profiles for PCBs and organochlorine pesticides and account for the wind speed gradient with height. Average wind speeds ranged from 0.3 to 4.5 m s(-1) over the 40 day deployment, increasing with height Two low volume active air samples (AAS), one collected at 25 m and one at 73 m over the 40 day deployment showed no significant concentration differences for target compounds. As expected, the target compounds taken up by PAS reflected the wind profile with height This wind-dependency of the PAS was also reflected in the results of the DCs. A correction based on the DC approach successfully accounted for the effect of wind on PAS sampling rates, yielding a profile consistent with the AAS. Interestingly, in terms of absolute air concentrations, there were differences between the AAS and PAS-derived values for some target compounds. These were attributed to different sampling characteristics of the two approaches that may have resulted in slightly different air masses being sampled. Based on the results of this study, guidelines are presented for the use of DCs and for the calibration of PAS using AAS.

  3. Detection of airborne bacteria in a duck production facility with two different personal air sampling devices for an exposure assessment.

    PubMed

    Martin, Elena; Dziurowitz, Nico; Jäckel, Udo; Schäfer, Jenny

    2015-01-01

    Prevalent airborne microorganisms are not well characterized in industrial animal production buildings with respect to their quantity or quality. To investigate the work-related microbial exposure, personal bioaerosol sampling during the whole working day is recommended. Therefore, bioaerosol sampling in a duck hatchery and a duck house with two personal air sampling devices, a filter-based PGP and a NIOSH particle size separator, was performed. Subsequent, quantitative and qualitative analyses were carried out with" culture independent methods. Total cell concentrations (TCC) determined via fluorescence microscopy showed no difference between the two devices. In average, 8 × 10(6) cells/m(3) were determined in the air of the duck hatchery and 5 × 10(7) cells/m(3) in the air of the duck house. A Generated Restriction Fragment Length Polymorphism (RFLP) pattern revealed deviant bacterial compositions comparing samples collected with both devices. Clone library analyses based on 16S rRNA gene sequence analysis from the hatchery's air showed 65% similarity between the two sampling devices. Detailed 16S rRNA gene sequence analyses showed the occurrence of bacterial species like Acinetobacter baumannii, Enterococcus faecalis, Escherichia sp., and Shigella sp.; and a group of Staphylococcus delphini, S. intermedius, and S. pseudintermedius that provided the evidence of potential exposure to risk group 2 bacteria at the hatchery workplace. Size fractionated sampling with the developed by the Institute for Occupational Safety and Health of the German Social Accident Insurance (IFA) device revealed that pathogenic bacteria would deposit in the inhalable, the thorax, and possibly alveolar dust fraction according to EN481. TCC analysis showed the deposition of bacterial cells in the third stage (< 1μm) at the NIOSH device which implies that bacteria can reach deep into the lungs and contaminate the alveolus after inhalation. Nevertheless, both personal sampling devices

  4. Identification of oxidation products of solanesol produced during air sampling for tobacco smoke by electrospray mass spectrometry and HPLC.

    PubMed

    Tucker, Samuel P; Pretty, Jack R

    2005-10-01

    Solanesol, a 45-carbon, trisesquiterpenoid alcohol found in tobacco leaves and tobacco smoke, has been used as a quantitative marker for tobacco smoke for years. However, solanesol appears to be unreliable as a quantitative marker for tobacco smoke during environmental air sampling because it can be degraded substantially when present as a component of tobacco smoke and by as much as 100% when present as pure solanesol on fortified filters during air sampling. Since there is strong evidence that ozone is the agent responsible for the degradation, solanesol appears to be unreliable as a quantitative marker during indoor air sampling when indoor levels of ozone are greater than about 15 ppb. The degree of loss of pure solanesol is directly proportional to the concentration of ozone and the length of the sampling period and depends on the type of 37 mm membrane filter used for air sampling (PTFE or quartz fiber). While the degree of loss of solanesol is inversely proportional to the relative humidity of the air at a sampling rate of 1.7 L min(-1), the degree of loss is virtually independent of relative humidity at a lower sampling rate; i.e., 0.25 L min(-1). A curve of loss of solanesol on a filter versus concentration of ozone from an ozone generator is virtually identical to a curve segment based on atmospheric ozone under the same conditions of air sampling. Oxidation of solanesol by ozone to approximately 25 to 60% completion produces at least three series of products for a total of at least 26 compounds: (1) isoprenoid acetones, (2)omega-hydroxyisoprenoid acetaldehydes, and (3) isoprenoid oxoaldehydes. All products in each series were tentatively identified as their derivatives with 2-(p-aminophenyl)ethanol (APE) by electrospray mass spectrometry (ES-MS). Ten ozonation products were detected as their 2,4-dinitrophenylhydrazine derivatives by HPLC at 360 nm: 4-oxopentanal and nine isoprenoid acetones (acetone, 6-methyl-5-hepten-2-one, geranylacetone

  5. Evaluation of sampling and analytical methodology for polynuclear aromatic compounds in indoor air. Final report, 1 March-30 September 1985

    SciTech Connect

    Chuang, C.C.; Mack, G.A.; Mondron, P.J.; Petersen, B.A.

    1985-10-01

    The objective of this project was to develop a generic sampling and analytical methodology to characterize the polynuclear aromatic hydrocarbon (PAH) concentrations in air within various microenvironments. The following three studies were performed: evaluation of analytical methods, design of a sampling method, and design of a pilot study. Two analytical methods, high performance liquid chromatography with ultraviolet adsorption and fluorescence detection and gas chromatography/mass spectrometry, were evaluated for the determination of PAHs and their derivatives in air within microenvironments. The results showed that gas chromatography/positive chemical ionization massspectrometry with data acquisition in the selected ion-monitoring mode is the preferred analytical approach. A modified EPA high-volume sampler, consisting of a quartz fiber filter and a polyurethane foam cartridge, is proposed for use in a future experimental study. A literature review was conducted to determine what is known about the contribution of cigarette smoke to the levels of PAHs in air within microenvironments and to evaluate the use of quinoline and isoquinoline as possible marker compounds for the levels of cigarette smoke. A pilot study was designed to assess PAH levels in air found in residences. A study using this design, was conducted in Columbus, Ohio, during the winter of 1983/84. These results can then be applied to a future large-scale study involving the measurement of human exposure to PAH in air.

  6. Scheduling whole-air samples above the Trade Wind Inversion from SUAS using real-time sensors

    NASA Astrophysics Data System (ADS)

    Freer, J. E.; Greatwood, C.; Thomas, R.; Richardson, T.; Brownlow, R.; Lowry, D.; MacKenzie, A. R.; Nisbet, E. G.

    2015-12-01

    Small Unmanned Air Systems (SUAS) are increasingly being used in science applications for a range of applications. Here we explore their use to schedule the sampling of air masses up to 2.5km above ground using computer controlled bespoked Octocopter platforms. Whole-air sampling is targeted above, within and below the Trade Wind Inversion (TWI). On-board sensors profiled the TWI characteristics in real time on ascent and, hence, guided the altitudes at which samples were taken on descent. The science driver for this research is investigation of the Southern Methane Anomaly and, more broadly, the hemispheric-scale transport of long-lived atmospheric tracers in the remote troposphere. Here we focus on the practical application of SUAS for this purpose. Highlighting the need for mission planning, computer control, onboard sensors and logistics in deploying such technologies for out of line-of-sight applications. We show how such a platform can be deployed successfully, resulting in some 60 sampling flights within a 10 day period. Challenges remain regarding the deployment of such platforms routinely and cost-effectively, particularly regarding training and support. We present some initial results from the methane sampling and its implication for exploring and understanding the Southern Methane Anomaly.

  7. ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT - BAGHOUSE FILTRATION PRODUCTS - AIR PURATOR CORPORATION HUYGLAS 1405M FILTER SAMPLE

    EPA Science Inventory

    Baghouse filtration products (BFPs) were evaluated by the Air Pollution Control Technology (APCT) pilot of the Environmental Technology Verification (ETV) Program. The performance factor verified was the mean outlet particle concentration for the filter fabric as a function of th...

  8. Special tablets containing cellulose binder and Sr internal standard for simplifying X-ray fluorescence analysis of powder samples

    NASA Astrophysics Data System (ADS)

    Mzyk, Zofia; Anyszkiewicz, Jacek; Gorewoda, Tadeusz

    2015-12-01

    The addition of a constant amount of SrCO3 was observed to be the proper internal standard for analysis by wavelength-dispersive X-ray fluorescence spectrometry to correct the matrix and grain size effects of many constituents. The weighing of constant amounts of SrCO3, binder and sample allowed for the preparation time for analysis to be extended, and special tablets containing binder and SrCO3 were developed. Several substances were tested as binders, among which microcrystalline cellulose was chosen for further study. The prepared tablets were checked for their weight stability and the repeatability of SrCO3 addition. The tablets were then used to prepare pellets from geological samples for X-ray fluorescence analysis. The exemplary application and calibration curves for several analytes confirmed that the prepared tablets could be useful for the pelletizing of such materials to compensate for matrix effects.

  9. Exposure assessment of monoterpenes and styrene: a comparison of air sampling and biomonitoring

    PubMed Central

    Liljelind, I; Rappaport, S; Eriksson, K; Andersson, J; Bergdahl, I; Sunesson, A; Jarvholm, B

    2003-01-01

    Background: Within- and between-worker variance components have seldom been reported for both environmental and biological data collected from the same persons. Aims: To estimate these variance components and their ratio for air contaminants and urinary metabolites in two different work environments and to predict the attenuation of exposure-response relationships based on these measures. Methods: Parallel measurements of air and urine were performed among workers exposed to monoterpenes in sawmills (urinary metabolite: verbenol) and styrene in reinforced plastics factories (urinary metabolite: mandelic acid). Results: Among the sawmill workers, variance components of the air and urinary verbenol results were similar; for the reinforced plastics workers the estimated between-worker variance component was greater for styrene in air than mandelic acid in urine. This suggests that attenuation bias would be about equal if air or biological monitoring were employed for monoterpene exposures, but would be greater if urinary mandelic acid were used instead of airborne styrene in an investigation of styrene exposure. Conclusions: Personal air samplers provide data with similar or superior quality to urinary metabolites as measures of exposure to these monoterpenes in sawmills and styrene in reinforced plastics factories. PMID:12883022

  10. Thermal and Evolved Gas Analysis of Geologic Samples Containing Organic Materials: Implications for the 2007 Mars Phoenix Scout Mission

    NASA Technical Reports Server (NTRS)

    Lauer, H. V., Jr.; Ming, Douglas W.; Golden, D. C.; Boynton, W. V.

    2006-01-01

    The Thermal and Evolved Gas Analyzer (TEGA) instrument scheduled to fly onboard the 2007 Mars Phoenix Scout Mission will perform differential scanning calorimetry (DSC) and evolved gas analysis (EGA) of soil samples and ice collected from the surface and subsurface at a northern landing site on Mars. We have been developing a sample characterization data library using a laboratory DSC integrated with a quadrupole mass spectrometer to support the interpretations of TEGA data returned during the mission. The laboratory TEGA test-bed instrument has been modified to operate under conditions similar to TEGA, i.e., reduced pressure (e.g., 100 torr) and reduced carrier gas flow rates. We have previously developed a TEGA data library for a variety of volatile-bearing mineral phases, including Fe-oxyhydroxides, phyllosilicates, carbonates, and sulfates. Here we examine the thermal and evolved gas properties of samples that contain organics. One of the primary objectives of the Phoenix Scout Mission is to search for habitable zones by assessing organic or biologically interesting materials in icy soil. Nitrogen is currently the carrier gas that will be used for TEGA. In this study, we examine two possible modes of detecting organics in geologic samples; i.e., pyrolysis using N2 as the carrier gas and combustion using O2 as the carrier gas.

  11. Perfluoroalkyl acids and their precursors in indoor air sampled in children's bedrooms.

    PubMed

    Winkens, Kerstin; Koponen, Jani; Schuster, Jasmin; Shoeib, Mahiba; Vestergren, Robin; Berger, Urs; Karvonen, Anne M; Pekkanen, Juha; Kiviranta, Hannu; Cousins, Ian T

    2017-03-01

    The contamination levels and patterns of perfluoroalkyl acids (PFAAs) and their precursors in indoor air of children's bedrooms in Finland, Northern Europe, were investigated. Our study is among the most comprehensive indoor air monitoring studies (n = 57) and to our knowledge the first one to analyse air in children's bedrooms for PFASs (17 PFAAs and 9 precursors, including two acrylates, 6:2 FTAC and 6:2 FTMAC). The most frequently detected compound was 8:2 fluorotelomer alcohol (8:2 FTOH) with the highest median concentration (3570 pg/m(3)). FTOH concentrations were generally similar to previous studies, indicating that in 2014/2015 the impact of the industrial transition had been minor on FTOH levels in indoor air. However, in contrast to earlier studies (with one exception), median concentrations of 6:2 FTOH were higher than 10:2 FTOH. The C8 PFAAs are still the most abundant acids, even though they have now been phased out by major manufacturers. The mean concentrations of FOSE/As, especially MeFOSE (89.9 pg/m(3)), were at least an order of magnitude lower compared to previous studies. Collectively the comparison of FTOHs, PFAAs and FOSE/FOSAs with previous studies indicates that indoor air levels of PFASs display a time lag to changes in production of several years. This is the first indoor air study investigating 6:2 FTMAC, which was frequently detected (58%) and displayed some of the highest maximum concentrations (13 000 pg/m(3)). There were several statistically significant correlations between particular house and room characteristics and PFAS concentrations, most interestingly higher EtFOSE air concentrations in rooms with plastic floors compared to wood or laminate.

  12. Liquid chromatography time-of-flight mass spectrometry evaluation of fungicides reactivity in free chlorine containing water samples.

    PubMed

    Rodríguez-Cabo, T; Paganini, M; Carpinteiro, I; Fontenla, L; Rodríguez, I; Pietrogrande, M C; Cela, R

    2013-02-01

    Liquid chromatography (LC) combined with tandem mass spectrometry (MS/MS), based on the use of a hybrid quadrupole-time-of-flight mass analyzer, was used to investigate the reactivity of nine fungicides in free chlorine-containing water samples. Three of the selected compounds (fenhexamid, FEN; pyrimethanil, PYR; and cyprodinil, CYP) displayed a poor stability in presence of moderate chlorine levels; thus, the effects of different parameters on their half-lives (t(1/2)) were evaluated. Sample pH, bromide traces, and the water matrix affected their relative stabilities. Despite such variations, the three fungicides are degraded at significant rates not only in ultrapure, but also in surface water spiked with chlorine levels up to 2 µg ml(-1), and when mixed with chlorinated tap water, generating several transformation products (TPs). The time-course of precursor species and their TPs was followed in the LC-MS mode, using the information contained in accurate, full scan mass spectra (MS) to propose the empirical formulae of TPs. Thereafter, their ion product scan (MS/MS) spectra were considered to set their chemical structures; allowing, in some cases, to distinguish between isomeric TPs. The reaction pathway of FEN, the less stable fungicide, involved just an electrophilic substitution of hydrogen per chlorine, or bromine, and cleavage of the molecule to render an amide. PYR and CYP shared common reaction routes consisting of halogenation, hydroxylation, and condensation processes leading to complex mixtures of TPs, which were relatively stable to further transformations.

  13. Quantification of fluorine traces in solid samples using CaF molecular emission bands in atmospheric air Laser-Induced Breakdown Spectroscopy

    NASA Astrophysics Data System (ADS)

    Alvarez-Llamas, C.; Pisonero, J.; Bordel, N.

    2016-09-01

    Direct solid determination of trace amounts of fluorine using Laser-Induced Breakdown Spectroscopy (LIBS) is a challenging task due to the low excitation efficiency of this element. Several strategies have been developed to improve the detection capabilities, including the use of LIBS in a He atmosphere to enhance the signal to background ratios of F atomic emission lines. An alternative method is based on the detection of the molecular compounds that are formed with fluorine in the LIBS plasma. In this work, the detection of CaF molecular emission bands is investigated to improve the analytical capabilities of atmospheric air LIBS for the determination of fluorine traces in solid samples. In particular, Cu matrix samples containing different fluorine concentration (between 50 and 600 μg/g), and variable amounts of Ca, are used to demonstrate the linear relationships between CaF emission signal and F concentration. Limits of detection for fluorine are improved by more than 1 order of magnitude using CaF emission bands versus F atomic lines, in atmospheric-air LIBS. Furthermore, a toothpaste powder sample is used to validate this analytical method. Good agreement is observed between the nominal and the predicted fluorine mass-content.

  14. Solid-Sorbent Air Sampler

    NASA Technical Reports Server (NTRS)

    Galen, T. J.

    1986-01-01

    Portable unit takes eight 24-hour samples. Volatile organic compounds in air collected for analysis by portable, self-contained sampling apparatus. Sampled air drawn through sorbent material, commercial porous polymer of 2, 3-diphenyl-p-phenylene oxide. High-boiling-point organic compounds adsorbed onto polymer, while low-boiling-point organics pass through and returned to atmosphere. Sampler includes eight sample tubes filled with polymeric sorbent. Organic compounds in atmosphere absorbed when air pumped through sorbent. Designed for checking air in spacecraft, sampler adaptable to other applications as leak detection, gas-mixture analysis, and ambient-air monitoring.

  15. Demonstration of oxygen-enriched air staging at Owens-Brockway glass containers. Quarterly technical progress report for the period August 1, 1996--October 31, 1996

    SciTech Connect

    Rue, D.; Abbasi, H.

    1997-03-01

    The objective of the program is to demonstrate the use of a previously developed combustion modification technology to reduce NO, emissions from sideport regenerative container glass melters. This technology, known as oxygen-enriched air staging (OEAS), has been demonstrated, and is now being commercialized for endport container glass furnaces. This report focuses on full furnace parametric and long-term testing.

  16. The lung cancer breath signature: a comparative analysis of exhaled breath and air sampled from inside the lungs

    PubMed Central

    Capuano, Rosamaria; Santonico, Marco; Pennazza, Giorgio; Ghezzi, Silvia; Martinelli, Eugenio; Roscioni, Claudio; Lucantoni, Gabriele; Galluccio, Giovanni; Paolesse, Roberto; Di Natale, Corrado; D’Amico, Arnaldo

    2015-01-01

    Results collected in more than 20 years of studies suggest a relationship between the volatile organic compounds exhaled in breath and lung cancer. However, the origin of these compounds is still not completely elucidated. In spite of the simplistic vision that cancerous tissues in lungs directly emit the volatile metabolites into the airways, some papers point out that metabolites are collected by the blood and then exchanged at the air-blood interface in the lung. To shed light on this subject we performed an experiment collecting both the breath and the air inside both the lungs with a modified bronchoscopic probe. The samples were measured with a gas chromatography-mass spectrometer (GC-MS) and an electronic nose. We found that the diagnostic capability of the electronic nose does not depend on the presence of cancer in the sampled lung, reaching in both cases an above 90% correct classification rate between cancer and non-cancer samples. On the other hand, multivariate analysis of GC-MS achieved a correct classification rate between the two lungs of only 76%. GC-MS analysis of breath and air sampled from the lungs demonstrates a substantial preservation of the VOCs pattern from inside the lung to the exhaled breath. PMID:26559776

  17. Thermal desorption-gas chromatography-mass spectrometry method to determine phthalate and organophosphate esters from air samples.

    PubMed

    Aragón, M; Borrull, F; Marcé, R M

    2013-08-16

    A method based on thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS) has been developed to determine four organophosphate esters, seven phthalate esters, and bis(2-ethylhexyl) adipate in the gas phase from harbour and urban air samples. The method involves the sampling of 1.5L of air in a Tenax TA sorbent tube followed by thermal desorption (using a Tenax TA cryogenic trap) coupled to gas chromatography-mass spectrometry. The repeatability of the method expressed as %RSD (n=3) is less than 15% and the MQLs are between 0.007μgm(-3) (DMP, TBP, BBP, TPP and DnOP) and 6.7μgm(-3) (DEHP). The method was successfully applied in two areas (urban and harbour) testing two and three points in each one, respectively. Some of these compounds were found in both urban and harbour samples. Di-(2-ethylhexyl)phthalate was the most abundant compound found in both areas at concentration levels between 6.7μgm(-3) and 136.4μgm(-3). This study demonstrates that thermal desorption is an efficient method for the determination of these semi-volatile compounds in the gas phase fraction of air samples.

  18. Evaluation of mixing downstream of tees in duct systems with respect to single point representative air sampling.

    PubMed

    Kim, Taehong; O'Neal, Dennis L; Ortiz, Carlos

    2006-09-01

    Air duct systems in nuclear facilities must be monitored with continuous sampling in case of an accidental release of airborne radionuclides. The purpose of this work is to identify the air sampling locations where the velocity and contaminant concentrations fall below the 20% coefficient of variation required by the American National Standards Institute/Health Physics Society N13.1-1999. Experiments of velocity and tracer gas concentration were conducted on a generic "T" mixing system which included combinations of three sub ducts, one main duct, and air velocities from 0.5 to 2 m s (100 to 400 fpm). The experimental results suggest that turbulent mixing provides the accepted velocity coefficients of variation after 6 hydraulic diameters downstream of the T-junction. About 95% of the cases achieved coefficients of variation below 10% by 6 hydraulic diameters. However, above a velocity ratio (velocity in the sub duct/velocity in the main duct) of 2, velocity profiles were uniform in a shorter distance downstream of the T-junction as the velocity ratio went up. For the tracer gas concentration, the distance needed for the coefficients of variation to drop 20% decreased with increasing velocity ratio due to the sub duct airflow momentum. The results may apply to other duct systems with similar geometries and, ultimately, be a basis for selecting a proper sampling location under the requirements of single point representative sampling.

  19. The lung cancer breath signature: a comparative analysis of exhaled breath and air sampled from inside the lungs.

    PubMed

    Capuano, Rosamaria; Santonico, Marco; Pennazza, Giorgio; Ghezzi, Silvia; Martinelli, Eugenio; Roscioni, Claudio; Lucantoni, Gabriele; Galluccio, Giovanni; Paolesse, Roberto; Di Natale, Corrado; D'Amico, Arnaldo

    2015-11-12

    Results collected in more than 20 years of studies suggest a relationship between the volatile organic compounds exhaled in breath and lung cancer. However, the origin of these compounds is still not completely elucidated. In spite of the simplistic vision that cancerous tissues in lungs directly emit the volatile metabolites into the airways, some papers point out that metabolites are collected by the blood and then exchanged at the air-blood interface in the lung. To shed light on this subject we performed an experiment collecting both the breath and the air inside both the lungs with a modified bronchoscopic probe. The samples were measured with a gas chromatography-mass spectrometer (GC-MS) and an electronic nose. We found that the diagnostic capability of the electronic nose does not depend on the presence of cancer in the sampled lung, reaching in both cases an above 90% correct classification rate between cancer and non-cancer samples. On the other hand, multivariate analysis of GC-MS achieved a correct classification rate between the two lungs of only 76%. GC-MS analysis of breath and air sampled from the lungs demonstrates a substantial preservation of the VOCs pattern from inside the lung to the exhaled breath.

  20. The lung cancer breath signature: a comparative analysis of exhaled breath and air sampled from inside the lungs

    NASA Astrophysics Data System (ADS)

    Capuano, Rosamaria; Santonico, Marco; Pennazza, Giorgio; Ghezzi, Silvia; Martinelli, Eugenio; Roscioni, Claudio; Lucantoni, Gabriele; Galluccio, Giovanni; Paolesse, Roberto; di Natale, Corrado; D'Amico, Arnaldo

    2015-11-01

    Results collected in more than 20 years of studies suggest a relationship between the volatile organic compounds exhaled in breath and lung cancer. However, the origin of these compounds is still not completely elucidated. In spite of the simplistic vision that cancerous tissues in lungs directly emit the volatile metabolites into the airways, some papers point out that metabolites are collected by the blood and then exchanged at the air-blood interface in the lung. To shed light on this subject we performed an experiment collecting both the breath and the air inside both the lungs with a modified bronchoscopic probe. The samples were measured with a gas chromatography-mass spectrometer (GC-MS) and an electronic nose. We found that the diagnostic capability of the electronic nose does not depend on the presence of cancer in the sampled lung, reaching in both cases an above 90% correct classification rate between cancer and non-cancer samples. On the other hand, multivariate analysis of GC-MS achieved a correct classification rate between the two lungs of only 76%. GC-MS analysis of breath and air sampled from the lungs demonstrates a substantial preservation of the VOCs pattern from inside the lung to the exhaled breath.

  1. Investigation on per- and polyfluorinated compounds in paired samples of house dust and indoor air from Norwegian homes.

    PubMed

    Haug, Line S; Huber, Sandra; Schlabach, Martin; Becher, Georg; Thomsen, Cathrine

    2011-10-01

    Per- and polyfluorinated compounds (PFCs) have been found to be ubiquitously distributed in human populations, however the sources of human exposure are not fully characterized. A wide range of PFCs were determined in paired samples of indoor air and dust from 41 Norwegian households. Up to 18 ionic and 9 neutral PFCs were detected. The concentrations found are comparable to or lower than what has previously been reported in North America, Europe, and Asia. The highest median concentrations in dust were observed for perfluorohexanoic acid (28 ng/g), perfluorononanoic acid (23 ng/g), perfluorododecanoic acid (19 ng/g), and perfluorooctanoic acid (18 ng/g). However, perfluoroalkyl sulfonic acids (PFSAs) were also frequently detected. Fluortelomer alcohols were the most prominent compounds found in indoor air, with median concentrations for 8:2 fluortelomer alcohol, 10:2 fluortelomer alcohol, and 6:2 fluortelomer alcohol of 5173, 2822, and 933 pg/m(3) air, respectively. All perfluoroalkyl sulfonamides and sulfonamidoethanols (FOSA/FOSEs) were detected in more than 40% of the air samples. For the first time, significant positive correlations (p < 0.05) between PFSAs in house dust and FOSA/FOSEs in the indoor air have been shown, supporting the hypothesis that FOSA/FOSEs may be transformed to PFSAs. Further, we found the age of the residence to be a predictor of PFC concentrations in both indoor air and house dust. These results are important for estimating the exposure to PFCs from the indoor environment and for characterization of exposure pathways.

  2. Direct Trace Element Analysis of Liquid Blood Samples by In-Air Ion Beam Analytical Techniques (PIXE-PIGE).

    PubMed

    Huszank, Robert; Csedreki, László; Török, Zsófia

    2017-02-07

    There are various liquid materials whose elemental composition is of interest in various fields of science and technology. In many cases, sample preparation or the extraction can be complicated, or it would destroy the original environment before the analysis (for example, in the case of biological samples). However, multielement direct analysis of liquid samples can be realized by an external PIXE-PIGE measurement system. Particle-induced X-ray and gamma-ray emission spectroscopy (PIXE, PIGE) techniques were applied in external (in-air) microbeam configuration for the trace and main element determination of liquid samples. The direct analysis of standard solutions of several metal salts and human blood samples (whole blood, blood serum, blood plasma, and formed elements) was realized. From the blood samples, Na, P, S, Cl, K, Ca, Fe, Cu, Zn, and Br elemental concentrations were determined. The focused and scanned ion beam creates an opportunity to analyze very small volume samples (∼10 μL). As the sample matrix consists of light elements, the analysis is possible at ppm level. Using this external beam setup, it was found that it is possible to determine elemental composition of small-volume liquid samples routinely, while the liquid samples do not require any preparation processes, and thus, they can be analyzed directly. In the case of lower concentrations, the method is also suitable for the analysis (down to even ∼1 ppm level) but with less accuracy and longer measurement times.

  3. 75 FR 56538 - Air Products and Chemicals, Inc.; Analysis of Proposed Agreement Containing Consent Orders to Aid...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-16

    ... ] Consent Agreement, Air Products is required, among other things, to divest 15 air separation units (``ASUs... From the Federal Register Online via the Government Publishing Office FEDERAL TRADE COMMISSION Air.... Comments should refer to``Air Products, Inc., File No. 101 0093'' to facilitate the organization...

  4. CTEPP STANDARD OPERATING PROCEDURE FOR EXTRACTING AND PREPARING AIR SAMPLES FOR ANALYSIS OF POLAR PERSISTENT ORGANIC POLLUTANTS (SOP-5.13)

    EPA Science Inventory

    The method for extracting and preparing indoor and outdoor air samples for analysis of polar persistent organic pollutants is summarized in this SOP. It covers the preparation of samples that are to be analyzed by gas chromatography/mass spectrometry.

  5. Assessment of Air Quality in the Shuttle and International Space Station (ISS) Based on Samples Returned by STS-104 at the Conclusion of 7A

    NASA Technical Reports Server (NTRS)

    James, John T.

    2001-01-01

    The toxicological assessment of air samples returned at the end of the STS-l04 (7 A) flight to the ISS is reported. ISS air samples were taken in June and July 2001 from the Service Module, FGB, and U.S. Laboratory using grab sample canisters (GSCs) and/or formaldehyde badges. Preflight and end-of-mission samples were obtained from Atlantis using GSCs. Solid sorbent air sampler (SSAS) samples were obtained from the ISS in April, June, and July. Analytical methods have not changed from earlier reports, and all quality control measures were met.

  6. Analysis of Dust Samples Collected from an Unused Spent Nuclear Fuel Interim Storage Container at Hope Creek, Delaware.

    SciTech Connect

    Bryan, Charles R.; Enos, David

    2015-03-01

    In July, 2014, the Electric Power Research Institute and industry partners sampled dust on the surface of an unused canister that had been stored in an overpack at the Hope Creek Nuclear Generating Station for approximately one year. The foreign material exclusion (FME) cover that had been on the top of the canister during storage, and a second recently - removed FME cover, were also sampled. This report summarizes the results of analyses of dust samples collected from the unused Hope Creek canister and the FME covers. Both wet and dry samples of the dust/salts were collected, using SaltSmart(TM) sensors and Scotch - Brite(TM) abrasive pads, respectively. The SaltSmart(TM) samples were leached and the leachate analyzed chemically to determine the composition and surface load per unit area of soluble salts present on the canister surface. The dry pad samples were analyzed by X-ray fluorescence and by scanning electron microscopy to determine dust texture and mineralogy; and by leaching and chemical analysis to deter mine soluble salt compositions. The analyses showed that the dominant particles on the canister surface were stainless steel particles, generated during manufacturing of the canister. Sparse environmentally - derived silicates and aluminosilicates were also present. Salt phases were sparse, and consisted of mostly of sulfates with rare nitrates and chlorides. On the FME covers, the dusts were mostly silicates/aluminosilicates; the soluble salts were consistent with those on the canister surface, and were dominantly sulfates. It should be noted that the FME covers were w ashed by rain prior to sampling, which had an unknown effect of the measured salt loads and compositions. Sulfate salts dominated the assemblages on the canister and FME surfaces, and in cluded Ca - SO4 , but also Na - SO4 , K - SO4 , and Na - Al - SO4 . It is likely that these salts were formed by particle - gas conversion reactions, either

  7. Integrating silicon nanowire field effect transistor, microfluidics and air sampling techniques for real-time monitoring biological aerosols.

    PubMed

    Shen, Fangxia; Tan, Miaomiao; Wang, Zhenxing; Yao, Maosheng; Xu, Zhenqiang; Wu, Yan; Wang, Jindong; Guo, Xuefeng; Zhu, Tong

    2011-09-01

    Numerous threats from biological aerosol exposures, such as those from H1N1 influenza, SARS, bird flu, and bioterrorism activities necessitate the development of a real-time bioaerosol sensing system, which however is a long-standing challenge in the field. Here, we developed a real-time monitoring system for airborne influenza H3N2 viruses by integrating electronically addressable silicon nanowire (SiNW) sensor devices, microfluidics and bioaerosol-to-hydrosol air sampling techniques. When airborne influenza H3N2 virus samples were collected and delivered to antibody-modified SiNW devices, discrete nanowire conductance changes were observed within seconds. In contrast, the conductance levels remained relatively unchanged when indoor air or clean air samples were delivered. A 10-fold increase in virus concentration was found to give rise to about 20-30% increase in the sensor response. The selectivity of the sensing device was successfully demonstrated using H1N1 viruses and house dust allergens. From the simulated aerosol release to the detection, we observed a time scale of 1-2 min. Quantitative polymerase chain reaction (qPCR) tests revealed that higher virus concentrations in the air samples generally corresponded to higher conductance levels in the SiNW devices. In addition, the display of detection data on remote platforms such as cell phone and computer was also successfully demonstrated with a wireless module. The work here is expected to lead to innovative methods for biological aerosol monitoring, and further improvements in each of the integrated elements could extend the system to real world applications.

  8. Passive air sampling of organochlorine pesticides in a northeastern state of India, Manipur.

    PubMed

    Devi, Ningombam Linthoingambi; Qi, Shihua; Chakraborty, Paromita; Zhang, Gan; Yadav, Ishwar Chandra

    2011-01-01

    Thirty-six polyurethane foam disk passive air samplers (PUF-PAS) were deployed over a year during January to December, 2009 at three locations, i.e., Imphal (urban site), Thoubal (rural site) and Waithou (alpine site) of Manipur, to assess the seasonal local atmospheric emission of selected organochlorine pesticides (OCPs). The average concentration of HCHs monitored at mountain site during hot season (Mar, Apr, and May) and rainy seasons (Jun, Jul, Aug, and Sep) were 403 and 349 pg/m3, respectively. DDTs had a high concentration with 384 pg/m3 at rural site and 379 pg/m3 at urban site during hot seasons. Endosulfans and chlordane were found high in concentration during hot seasons (260 pg/m3) and low during retreating monsoon seasons (44 pg/m3) at rural site. Most of the OCPs concentrations were high during cultivation period. The OCP concentrations of rainy season were highly correlated (p < 0.01) with OCPs of hot seasons. Further, positive correlation (p < 0.05) was also obtained between cold seasons and retreating monsoon. Principal component analysis showed a significant correlation among the four seasons and distribution pattern of OCPs in air. Back trajectory analysis by using HYPSLIT model showed a long range air transport of OCPs to the present study area. Present OCP levels at Manipur is an outcome of both local emission and also movement of air mass by long range atmospheric transport.

  9. 32 CFR 806.27 - Samples of Air Force FOIA processing documents.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... documents. (a) This section includes suggested language in paragraph format that tracks Air Force and DoD... section, language in parentheses is for explanatory purposes only. Do not include any of the parenthetical language of this section in your FOIA correspondence. When optional language must be selected, the...

  10. An Inexpensive Autosampler to Maximize Throughput for an Ion Source that Samples Surfaces in Open Air

    EPA Science Inventory

    An autosampler was built to pull cotton swab heads mounted into a 3-foot long, square Al rod in ambient air through the He ionizing beam of a Direct Analysis in Real Time (DART) ion source interfaced to an orthogonal acceleration, time-of-flight mass spectrometer. The cost of th...

  11. Sampling of Malodorous Compounds in Air Using Stir Bar Sorbtive Extraction

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Twisters, (poly)-dimethylsiloxane-coated magnetic stir bars, were used to measure malodorous compounds in air. In initial experiments, a minimum deployment time was determined by preloading the stir bars with 10 compounds with a range of volatilities and polarities and then monitoring their loss. ...

  12. ASSESSMENT OF VAPOR INTRUSION USING INDOOR AND SUB-SLAB AIR SAMPLING

    EPA Science Inventory

    The objective of this investigation was to develop a method for evaluating vapor intrusion using indoor and sub-slab air measurement and at the same time directly assist EPA’s New England Regional Office in evaluating vapor intrusion in 15 homes and one business near the former R...

  13. Effect of Sampling Depth on Air-Sea CO2 Flux Estimates in River-Stratified Arctic Coastal Waters

    NASA Astrophysics Data System (ADS)

    Miller, L. A.; Papakyriakou, T. N.

    2015-12-01

    In summer-time Arctic coastal waters that are strongly influenced by river run-off, extreme stratification severely limits wind mixing, making it difficult to effectively sample the surface 'mixed layer', which can be as shallow as 1 m, from a ship. During two expeditions in southwestern Hudson Bay, off the Nelson, Hayes, and Churchill River estuaries, we confirmed that sampling depth has a strong impact on estimates of 'surface' pCO2 and calculated air-sea CO2 fluxes. We determined pCO2 in samples collected from 5 m, using a typical underway system on the ship's seawater supply; from the 'surface' rosette bottle, which was generally between 1 and 3 m; and using a niskin bottle deployed at 1 m and just below the surface from a small boat away from the ship. Our samples confirmed that the error in pCO2 derived from typical ship-board versus small-boat sampling at a single station could be nearly 90 μatm, leading to errors in the calculated air-sea CO2 flux of more than 0.1 mmol/(m2s). Attempting to extrapolate such fluxes over the 6,000,000 km2 area of the Arctic shelves would generate an error approaching a gigamol CO2/s. Averaging the station data over a cruise still resulted in an error of nearly 50% in the total flux estimate. Our results have implications not only for the design and execution of expedition-based sampling, but also for placement of in-situ sensors. Particularly in polar waters, sensors are usually deployed on moorings, well below the surface, to avoid damage and destruction from drifting ice. However, to obtain accurate information on air-sea fluxes in these areas, it is necessary to deploy sensors on ice-capable buoys that can position the sensors in true 'surface' waters.

  14. Inter-conversion of Chromium Species During Air Sampling: Effects of O3, NO2, SO2, Particle Matrices, Temperature and Humidity

    PubMed Central

    Huang, Lihui; Fan, Zhihua (Tina); Yu, Chang Ho; Hopke, Philip K.; Lioy, Paul J.; Buckley, Brian T.; Lin, Lin; Ma, Yingjun

    2013-01-01

    The inter-conversion between Cr(VI), a pulmonary carcinogen, and Cr(III), an essential human nutrient, poses challenges to the measurement of Cr(VI) in airborne particles. Chamber and field tests were conducted to identify the factors affecting Cr(VI)-Cr(III) inter-conversion in the basic filter medium under typical sampling conditions. In the chamber tests, isotopically enriched 53Cr(VI) and 50Cr(III) were spiked on diesel particulate matter (DPM) and secondary organic aerosol (SOA) that were pre-collected on a basic MCE filter. The filter samples were then exposed to clean air or the air containing SO2 (50 and 160 ppb), 100 ppb O3, or 150 ppb NO2 for 24 hours at 16.7 LPM flow rate at designated temperature (20 and 31°C) and RH (40% and 70%) conditions. Exposure to 160 ppb SO2 had the greatest effect on 53Cr(VI) reduction, with 53Cr(VI) recovery of 31.7 ± 15.8% (DPM) and 42.0 ± 7.9% (SOA). DPM and SOA matrix induced 53Cr(VI) reduction when exposed to clean air while reactive oxygen species in SOA could promote 50Cr(III) oxidation. Deliquescence when RH increased from 40% to 70% led to conversion of Cr(III) in SOA, whereas oxidized organics in DPM and SOA enhanced hygroscopicity and thus facilitated Cr(VI) reduction. Field tests showed seasonal variation of Cr(VI)-Cr(III) inter-conversion during sampling. Correction of the inter-conversion using USEPA method 6800 is recommended to improve accuracy of ambient Cr(VI) measurements. PMID:23550818

  15. Ultimate detectability of volatile organic compounds: how much further can we reduce their ambient air sample volumes for analysis?

    PubMed

    Kim, Yong-Hyun; Kim, Ki-Hyun

    2012-10-02

    To understand the ultimately lowest detection range of volatile organic compounds (VOCs) in air, application of a high sensitivity analytical system was investigated by coupling thermal desorption (TD) technique with gas chromatography (GC) and time-of-flight (TOF) mass spectrometry (MS). The performance of the TD-GC/TOF MS system was evaluated using liquid standards of 19 target VOCs prepared in the range of 35 pg to 2.79 ng per μL. Studies were carried out using both total ion chromatogram (TIC) and extracted ion chromatogram (EIC) mode. EIC mode was used for calibration to reduce background and to improve signal-to-noise. The detectability of 19 target VOCs, if assessed in terms of method detection limit (MDL, per US EPA definition) and limit of detection (LOD), averaged 5.90 pg and 0.122 pg, respectively, with the mean coefficient of correlation (R(2)) of 0.9975. The minimum quantifiable mass of target analytes, when determined using real air samples by the TD-GC/TOF MS, is highly comparable to the detection limits determined experimentally by standard. In fact, volumes for the actual detection of the major aromatic VOCs like benzene, toluene, and xylene (BTX) in ambient air samples were as low as 1.0 mL in the 0.11-2.25 ppb range. It was thus possible to demonstrate that most target compounds including those in low abundance could be reliably quantified at concentrations down to 0.1 ppb at sample volumes of less than 10 mL. The unique sensitivity of this advanced analytical system can ultimately lead to a shift in field sampling strategy with smaller air sample volumes facilitating faster, simpler air sampling (e.g., use of gas syringes rather than the relative complexity of pumps or bags/canisters), with greatly reduced risk of analyte breakthrough and minimal interference, e.g., from atmospheric humidity. The improved detection limits offered by this system can also enhance accuracy and measurement precision.

  16. CO2 isotope analyses using large air samples collected on intercontinental flights by the CARIBIC Boeing 767.

    PubMed

    Assonov, S S; Brenninkmeijer, C A M; Koeppel, C; Röckmann, T

    2009-03-01

    Analytical details for 13C and 18O isotope analyses of atmospheric CO2 in large air samples are given. The large air samples of nominally 300 L were collected during the passenger aircraft-based atmospheric chemistry research project CARIBIC and analyzed for a large number of trace gases and isotopic composition. In the laboratory, an ultra-pure and high efficiency extraction system and high-quality isotope ratio mass spectrometry were used. Because direct comparison with other laboratories was practically impossible, the extraction and measurement procedures were tested in considerable detail. Extracted CO2 was measured twice vs. two different working reference CO2 gases of different isotopic composition. The two data sets agree well and their distributions can be used to evaluate analytical errors due to isotope measurement, ion corrections, internal calibration consistency, etc. The calibration itself is based on NBS-19 and also verified using isotope analyses on pure CO2 gases (NIST Reference Materials (RMs) and NARCIS CO2 gases). The major problem encountered could be attributed to CO2-water exchange in the air sampling cylinders. This exchange decreased over the years. To exclude artefacts due to such isotopic exchange, the data were filtered to reject negative delta18O(CO2) values. Examples of the results are given.

  17. Magnesium, Iron and Aluminum in LLNL Air Particulate and Rain Samples with Reference to Magnesium in Industrial Storm Water

    SciTech Connect

    Esser, Bradley K.; Bibby, Richard K.; Fish, Craig

    2016-08-25

    Storm water runoff from the Lawrence Livermore National Laboratory’s (LLNL’s) main site and Site 300 periodically exceeds the Discharge Permit Numeric Action Level (NAL) for Magnesium (Mg) under the Industrial General Permit (IGP) Order No. 2014-0057-DWQ. Of particular interest is the source of magnesium in storm water runoff from the site. This special study compares new metals data from air particulate and precipitation samples from the LLNL main site and Site 300 to previous metals data for storm water from the main site and Site 300 and alluvial sediment from the main site to investigate the potential source of elevated Mg in storm water runoff. Data for three metals (Mg, Iron {Fe}, and Aluminum {Al}) were available from all media; data for additional metals, such as Europium (Eu), were available from rain, air particulates, and alluvial sediment. To attribute source, this study compared metals concentration data (for Mg, Al, and Fe) in storm water and rain; metal-metal correlations (Mg with Fe, Mg with Al, Al with Fe, Mg with Eu, Eu with Fe, and Eu with Al) in storm water, rain, air particulates, and sediments; and metal-metal ratios ((Mg/Fe, Mg/Al, Al/Fe, Mg/Eu, Eu/Fe, and Eu/Al) in storm water, rain, air particulates and sediments. The results presented in this study are consistent with a simple conceptual model where the source of Mg in storm water runoff is air particulate matter that has dry-deposited on impervious surfaces and subsequently entrained in runoff during precipitation events. Such a conceptual model is consistent with 1) higher concentrations of metals in storm water runoff than in precipitation, 2) the strong correlation of Mg with Aluminum (Al) and Iron (Fe) in both storm water and air particulates, and 3) the similarity in metal mass ratios between storm water and air particulates in contrast to the dissimilarity of metal mass ratios between storm water and precipitation or alluvial sediment. The strong correlation of Mg with Fe and Al

  18. Plutonium isotopic analysis system for plutonium samples enriched in sup 238 Pu in EP 60/61 containers

    SciTech Connect

    Ruhter, W.D.

    1990-06-01

    This user's manual is addressed to the Savannah River Site personnel (routine operators and supervisors) who perform measurements with the Pu-238 isotopic analysis system. Each chapter begins with a table of contents that lists the section title, illustrations, and tabular data presented in that chapter. The first chapter in this manual is an introduction to the system. Chapter 2 lists required settings for the system's commercial nuclear instrument modules. System operating procedures are given in Chapter 3. Chapter 4 contains routine and supervisorial operator interactions. Chapter 5 describes the system's short- and long-printout output formats. Chapter 6 gives instructions for changing system parameters. Error messages are listed and described Chapter 7. Chapter 8 contains a reference article on measuring relative plutonium isotopics in plutonium samples enriched in Pu-238. All commercial items mentioned in this manual are assumed to be functioning correctly for the purposes of system operation. Users are referred to individual equipment manufacturers' manuals for details of operation, trouble-shooting, and maintenance of this commercial equipment.

  19. Extraction of CO2 from air samples for isotopic analysis and limits to ultra high precision delta18O determination in CO2 gas.

    PubMed

    Werner, R A; Rothe, M; Brand, W A

    2001-01-01

    The determination of delta18O values in CO2 at a precision level of +/-0.02 per thousand (delta-notation) has always been a challenging, if not impossible, analytical task. Here, we demonstrate that beyond the usually assumed major cause of uncertainty - water contamination - there are other, hitherto underestimated sources of contamination and processes which can alter the oxygen isotope composition of CO2. Active surfaces in the preparation line with which CO2 comes into contact, as well as traces of air in the sample, can alter the apparent delta18O value both temporarily and permanently. We investigated the effects of different surface materials including electropolished stainless steel, Duran glass, gold and quartz, the latter both untreated and silanized. CO2 frozen with liquid nitrogen showed a transient alteration of the 18O/16O ratio on all surfaces tested. The time to recover from the alteration as well as the size of the alteration varied with surface type. Quartz that had been ultrasonically cleaned for several hours with high purity water (0.05 microS) exhibited the smallest effect on the measured oxygen isotopic composition of CO2 before and after freezing. However, quartz proved to be mechanically unstable with time when subjected to repeated large temperature changes during operation. After several days of operation the gas released from the freezing step contained progressively increasing trace amounts of O2 probably originating from inclusions within the quartz, which precludes the use of quartz for cryogenically trapping CO2. Stainless steel or gold proved to be suitable materials after proper pre-treatment. To ensure a high trapping efficiency of CO2 from a flow of gas, a cold trap design was chosen comprising a thin wall 1/4" outer tube and a 1/8" inner tube, made respectively from electropolished stainless steel and gold. Due to a considerable 18O specific isotope effect during the release of CO2 from the cold surface, the thawing time had to

  20. Final work plan : indoor air and ambient air sampling near the former CCC/USDA grain storage facility in Everest, Kansas.

    SciTech Connect

    LaFreniere, L. M.

    2010-05-24

    The Commodity Credit Corporation of the U.S. Department of Agriculture (CCC/USDA) operated a grain storage facility at the western edge of Everest, Kansas, from the early 1950s to the early 1970s. Sampling by the Kansas Department of Health and Environment (KDHE) in 1997 resulted in the detection of carbon tetrachloride in one domestic well (the Nigh well) northwest of the former facility. On behalf of the CCC/USDA, Argonne National Laboratory subsequently conducted a series of investigations to characterize the contamination (Argonne 2003, 2006a,b,c). Automatic, continuous monitoring of groundwater levels began in 2002 and is ongoing at six locations. The results have consistently indicated groundwater flow toward the north-northwest from the former CCC/USDA property to the Nigh property, then west-southwest from the Nigh property to the intermittent creek. Sitewide periodic groundwater and surface water sampling with analysis for volatile organic compounds (VOCs) began in 2008. Argonne's combined data indicate no significant downgradient extension of contamination since 2000. At present, the sampling is annual, as approved by the KDHE (2009) in response to a plan developed for the CCC/USDA (Argonne 2009). This document presents a plan for collecting indoor air samples in homes located along and adjacent to the defined extent of the carbon tetrachloride contamination. The plan was requested by the KDHE. Ambient air samples to represent the conditions along this pathway will also be taken. The purpose of the proposed work is to satisfy KDHE requirements and to collect additional data for assessing the risk to human health due to the potential upward migration of carbon tetrachloride and its primary degradation product (chloroform) into homes located in close proximity to the former grain storage facility, as well as along and within 100 ft laterally from the currently defined plume emanating from the former Everest facility. Investigation of the indoor air

  1. Remote mass spectrometric sampling of electrospray- and desorption electrospray-generated ions using an air ejector.

    PubMed

    Dixon, R Brent; Bereman, Michael S; Muddiman, David C; Hawkridge, Adam M

    2007-10-01

    A commercial air ejector was coupled to an electrospray ionization linear ion trap mass spectrometer (LTQ) to transport remotely generated ions from both electrospray (ESI) and desorption electrospray ionization (DESI) sources. We demonstrate the remote analysis of a series of analyte ions that range from small molecules and polymers to polypeptides using the AE-LTQ interface. The details of the ESI-AE-LTQ and DESI-AE-LTQ experimental configurations are described and preliminary mass spectrometric data are presented.

  2. The reproducibility of indoor air pollution (IAP) measurement: a test case for the measurement of key air pollutants from the pan frying of fish samples.

    PubMed

    Kim, Ki-Hyun; Kim, Yong-Hyun; Kim, Bo-Won; Ahn, Jeong-Hyeon; Bae, Min-Suk; Brown, Richard J C

    2014-01-01

    To assess the robustness of various indoor air quality (IAQ) indices, we explored the possible role of reproducibility-induced variability in the measurements of different pollutants under similar sampling and emissions conditions. Polluted indoor conditions were generated by pan frying fish samples in a closed room. A total of 11 experiments were carried out to measure a list of key variables commonly used to represent indoor air pollution (IAP) indicators such as particulate matter (PM: PM1, PM2.5, PM10, and TSP) and a set of individual volatile organic compounds (VOCs) with some odor markers. The cooking activity conducted as part of our experiments was successful to consistently generate significant pollution levels (mean PM10: 7110 μg m(-3) and mean total VOC (TVOC): 1400 μg m(-3), resp.). Then, relative standard error (RSE) was computed to assess the reproducibility between different IAP paramters measured across the repeated experiments. If the results were evaluated by an arbitrary criterion of 10%, the patterns were divided into two data groups (e.g., <10% for benzene and some aldehydes and >10% for the remainders). Most noticeably, TVOC had the most repeatable results with a reproducibility (RSE) value of 3.2% (n = 11).

  3. The Reproducibility of Indoor Air Pollution (IAP) Measurement: A Test Case for the Measurement of Key Air Pollutants from the Pan Frying of Fish Samples

    PubMed Central

    Kim, Bo-Won; Ahn, Jeong-Hyeon; Bae, Min-Suk; Brown, Richard J. C.

    2014-01-01

    To assess the robustness of various indoor air quality (IAQ) indices, we explored the possible role of reproducibility-induced variability in the measurements of different pollutants under similar sampling and emissions conditions. Polluted indoor conditions were generated by pan frying fish samples in a closed room. A total of 11 experiments were carried out to measure a list of key variables commonly used to represent indoor air pollution (IAP) indicators such as particulate matter (PM: PM1, PM2.5, PM10, and TSP) and a set of individual volatile organic compounds (VOCs) with some odor markers. The cooking activity conducted as part of our experiments was successful to consistently generate significant pollution levels (mean PM10: 7110 μg m−3 and mean total VOC (TVOC): 1400 μg m−3, resp.). Then, relative standard error (RSE) was computed to assess the reproducibility between different IAP paramters measured across the repeated experiments. If the results were evaluated by an arbitrary criterion of 10%, the patterns were divided into two data groups (e.g., <10% for benzene and some aldehydes and >10% for the remainders). Most noticeably, TVOC had the most repeatable results with a reproducibility (RSE) value of 3.2% (n = 11). PMID:25054167

  4. Evaluation of a portable X-ray fluorescence instrument for the determination of lead in workplace air samples.

    PubMed

    Morley, J C; Clark, C S; Deddens, J A; Ashley, K; Roda, S

    1999-05-01

    Occupational Safety and Health Administration (OSHA) regulations for worker exposure to lead specify worker protection levels based upon airborne concentrations of lead dust. The rapid, on-site determination of lead in air filter samples using a portable x-ray fluorescence (XRF) instrument with an attachment to hold the filter would expedite the exposure assessment process and facilitate compliance with the OSHA standards. A total of 65 lead in air filter samples were collected at bridge blasting lead-abatement projects using closed-faced, 37-mm cassettes with pre-loaded 0.8 micron pore size mixed cellulose ester membrane filters. The lead loading range of the data set was 0.1-1514.6 micrograms (micrograms) of lead/sample. Samples were initially analyzed with a field portable XRF (NITON 700) using an experimental non-destructive XRF method. Samples were subsequently analyzed using National Institute for Occupational Safety and Health (NIOSH) Method 7105 (Graphite Furnace AA) as a reference analytical method. The paired data were not normally distributed; therefore, the non-parametric Wilcoxon signed rank test was used for statistical analysis. There was no statistically significant difference between data from the field portable XRF method and the NIOSH method (p-value = 0.72). Linear regression of the data resulted in a slope of 0.959, a y-intercept of 5.20 micrograms, and an r2 of 0.985. The XRF limit of detection and limit of quantitation were determined to be 6.2 and 17 micrograms of lead/sample, respectively. The XRF method accuracy was +/- 16.4% (7.1%-27%, 90% confidence interval). The data presented in this study indicate that field-portable XRF can be used for the analysis of lead air filter samples over the range of 17 to 1500 micrograms of lead/sample. The practicing industrial hygienist can use field-portable XRF to produce a rapid, on-site determination of lead exposure that can immediately be communicated to workers and help identify appropriate levels

  5. 7 CFR 42.109 - Sampling plans for normal condition of container inspection, Tables I and I-A.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE COMMODITY STANDARDS AND STANDARD CONTAINER REGULATIONS STANDARDS FOR CONDITION OF FOOD CONTAINERS...

  6. Monitoring Iodine-129 in Air and Milk Samples Collected Near the Hanford Site: An Investigation of Historical Iodine Monitoring Data

    SciTech Connect

    Fritz, Brad G.; Patton, Gregory W.

    2006-01-01

    While other research has reported on the concentrations of 129I in the environment surrounding active nuclear fuel reprocessing facilities, there is a shortage of information regarding how the concentrations change once facilities close. At the Hanford Site, the Plutonium-Uranium Extraction (PUREX) chemical separation plant was operational between 1983 and 1990, during which time 129I concentrations in air and milk were measured. After the cessation of operations in 1990, plant emissions decreased 2.5 orders of magnitude over an 8 year period, and monitoring of environmental levels continued. An evaluation of air and milk 129I concentration data spanning the PUREX operation and post closure period was conducted to compare the changes in environmental levels of 129I measured. Measured concentrations over the monitoring period were below levels that could result in a potential human dose greater than 10 uSv. There was a significant and measurable difference in the measured air concentrations of 129I at different distances from the source, indicating a distinct Hanford fingerprint. Correlations between stack emissions of 129I and concentrations in air and milk indicate that atmospheric emissions were responsible for the 129I concentrations measured in environmental samples. The measured concentrations during PUREX operation were similar to observations made around a fuel reprocessing plant in Germany.

  7. STS 134, 135 and 26S Return Samples: Air Quality aboard Shuttle (STS-134) and International Space Station

    NASA Technical Reports Server (NTRS)

    James, John T.

    2011-01-01

    This is a very limited set of samples on which to perform an air quality assessment. However, based on these samples, we have no reason to believe that nominal ISS air is unsafe to breathe. We must continue to be vigilant when dealing with nominal atmospheres in ISS. New, unmanned modules require special attention when the crew first enters. Carbon Monoxide Accumulation aboard ISS: Beginning in late 2008 the nominal concentrations of CO began increasing gradually (Figure 1). The results from samples returned on this flight indicate that the CO concentrations, after dropping in late 2009, have cycled upward and then settled back to concentrations near 2 mg/m3. In any case, these changes are well below the 180-day SMAC for CO, which is17 mg/m3. There is no threat to crew health. Carbon Dioxide: This anthropogenic compound has drawn much attention recently because of the possibility that it could contribute to the effects of intracranial hypertension experienced because of spaceflight-induced fluid shifts. From now on we will maintain a plot (Figure 2) of carbon dioxide concentrations ( SD) by averaging the values found in the 3-5 mini-GSC samples taken each month in diverse locations of the ISS. This will enable us to estimate the average exposure of crewmembers to carbon dioxide during their stay aboard the ISS. In general, concentrations are being maintained below 3.5 mmHg. Figure 1

  8. Field Evaluation of a Passive Sampling Device for Hydrazines in Ambient Air

    DTIC Science & Technology

    1990-04-06

    1I1 Liquid Impinger Analysis.............................................. 12 Vanillin Color Dosimeter Analysis...colorimetric or coulometric spike); C - vanillin , D - impinger; and E - firebrick. The analytical laboratory only received the coded samples. The data...of absorbed light is proportional to the concentration of the hydrazone in the sample [12]. Vanillin Color Dosimeter Analysis. The same basic chemistry

  9. Sorption of a diverse set of organic chemical vapors onto XAD-2 resin: Measurement, prediction and implications for air sampling

    NASA Astrophysics Data System (ADS)

    Hayward, Stephen J.; Lei, Ying D.; Wania, Frank

    2011-01-01

    The wide-spread use of styrene-divinylbenzene-copolymeric resin (XAD-2) in air sampling necessitates a quantitative understanding of its sorption characteristics for organic chemicals. Inverse Gas Chromatography (IGC) was used to measure the sorption of a diverse set of 52 organic chemicals to XAD-2 at temperatures between 40 °C and 100 °C and at relative humidities between 0 and 87%. Even though relative humidity has been shown to influence sorption to other sorbents, it did not significantly influence most chemicals' sorption to XAD-2, indicating that water does not form a strong physical barrier to sorption on XAD-2 at high relative humidity. The resin-air partition coefficients ( KXAD) determined by IGC and the enthalpies of sorption derived from them were regressed against solute descriptors to derive poly-parameter Linear Free Energy Relationships (ppLFERs) which allow the estimation of KXAD for chemicals which are not sufficiently volatile to be amenable to IGC and for temperatures outside the experimental range. KXAD values at 20 °C estimated for a set of 296 chemicals for which solute descriptors are available, including polychlorinated biphenyls, polycyclic aromatic hydrocarbons, and pesticides, indicate that for many of the substances commonly found in the atmosphere sorption is higher to XAD-2 than to poly-urethane foam, another popular air sampling sorbent.

  10. Relative sensitivity of greenhouse pot plants to long-term exposures of NO- and NO2-containing air.

    PubMed

    Saxe, H

    1994-01-01

    Thirty-five cultivars of pot plants of 20 families were exposed for 50-64 days in a greenhouse facility to either 1 microl litre(-1) NO with 0.5 microl litre(-1) NO2, or 1 microl litre(-1) NO2 with 0.1 microl litre(-1) NO for 15 h each day, with air which was free from these gases as the reference. A sensitivity ranking of the pot plants was compiled, with the highest priority on visible injuries, followed by growth reductions, primarily as a response to the NO-dominated exposures, simulating the NOx-polluted environment in direct-fired, CO2-enriched greenhouses. This treatment reduced the leaf dry weight more than the number and area of the leaves. Twenty-two cultivars were significantly injured, while two (Hibicus sp, Epipremnum pinnatum, green) were significantly improved. The NOx-sensitivity of pot plants was highest in cultivars with variegated, small or narrow leaves, and in the Moraceae family. Nine cultivars (Ficus elastica 'Robusta', F. benjamina, F. pumila 'Sonny', Dieffenbachia maculata 'Camilla', F. elastica 'Tineke', Epipremnum pinnatum 'Marble Queen', Begonia elatior 'Nelson', Cyclamen persica, Poinsettia 'Mini') were specifically sensitive to the NO-containing exposure; six were specifically sensitive to the NO2-containing exposure (F. elastica 'Robusta', Asparagus den. 'Sprengeri', Hedera helix 'Shamrock', Aspledium nidus, Aster novo-belgii, Hypoestes phyl. 'Betina'); and 12 (Soleirolia soleirolii, Asparagus den. 'Sprengeri', H. helix 'Ester', Codiaeum 'Pictum', Rosa 'Minimo Red', F. benjamina 'Starlight', Saintpaulia ionantha 'light blue', F. pumila, Rhododendron simsii, H. helix 'Shamrock', Hibiscus sp., E. pinnatum) were equally sensitive to mixtures dominated by either gas, as measured by at least one response parameter.

  11. Ecotoxicological studies of environmental samples from Buenos Aires area using a standardized amphibian embryo toxicity test (AMPHITOX).

    PubMed

    Herkovits, Jorge; Perez-Coll, Cristina; Herkovits, Francisco D

    2002-01-01

    The toxicity of 34 environmental samples from potentially polluted and reference stations were evaluated by means of the AMPHITOX test from acute to chronic exposure according to the toxicity found in each sample. The samples were obtained from surface and ground water, leaches, industrial effluents and soils. The data, expressed in acute, short-term chronic and chronic Toxicity Units (TUa, TUstc and TUc) resulted in a maximal value of 1000 TUc, found in a leach, while the lower toxicity value was 1.4 TUa corresponding to two surface water samples. In five samples (four providing from reference places) no toxicity was detected. The results point out the possibility of evaluating the toxicity of a wide diversity of samples by means of AMPHITOX as a customized toxicity test. The fact that almost all samples with suspected toxicity in rivers and streams from the Metropolitan area of Buenos Aires city resulted toxic, indicates the need of enhanced stewardship of chemical substances for environmental and human health protection purposes.

  12. Technical assessment of compliance with workplace air sampling requirements at WRAP

    SciTech Connect

    HACKWORTH, M.F.

    1999-06-02

    The purpose of this Technical Assessment is to satisfy HSRCM-1, ''Hanford Site Radiological Control Manual'' Article 551.4 for a documented study of facility Workplace Air Monitoring (WAM) programs. HSRCM-1 is the primary guidance for radiological control at Waste Management Federal Services of Hanford, Inc. (WMH). The HSRCM-1 complies with Title 10. Part 835 of the Code of Federal Regulations (10CFR835). This document provides an evaluation of the compliance of the Waste Receiving and Processing facility (WRAP) WAM program to the criteria standards, requirements, and documents compliance with the requirements where appropriate. Where necessary, it also indicates changes needed to bring specific locations into compliance.

  13. The Impact of the Tree Prior on Molecular Dating of Data Sets Containing a Mixture of Inter- and Intraspecies Sampling.

    PubMed

    Ritchie, Andrew M; Lo, Nathan; Ho, Simon Y W

    2016-10-26

    In Bayesian phylogenetic analyses of genetic data, prior probability distributions need to be specified for the model parameters, including the tree. When Bayesian methods are used for molecular dating, available tree priors include those designed for species-level data, such as the pure-birth and birth-death priors, and coalescent-based priors designed for population-level data. However, molecular dating methods are frequently applied to data sets that include multiple individuals across multiple species. Such data sets violate the assumptions of both the speciation and coalescent-based tree priors, making it unclear which should be chosen and whether this choice can affect the estimation of node times. To investigate this problem, we used a simulation approach to produce data sets with different proportions of within- and between-species sampling under the multispecies coalescent model. These data sets were then analyzed under pure-birth, birth-death, constant-size coalescent, and skyline coalescent tree priors. We also explored the ability of Bayesian model testing to select the best-performing priors. We confirmed the applicability of our results to empirical data sets from cetaceans, phocids, and coregonid whitefish. Estimates of node times were generally robust to the choice of tree prior, but some combinations of tree priors and sampling schemes led to large differences in the age estimates. In particular, the pure-birth tree prior frequently led to inaccurate estimates for data sets containing a mixture of inter- and intraspecific sampling, whereas the birth-death and skyline coalescent priors produced stable results across all scenarios. Model testing provided an adequate means of rejecting inappropriate tree priors. Our results suggest that tree priors do not strongly affect Bayesian molecular dating results in most cases, even when severely misspecified. However, the choice of tree prior can be significant for the accuracy of dating results in the case

  14. Use of Respondent Driven Sampling (RDS) Generates a Very Diverse Sample of Men Who Have Sex with Men (MSM) in Buenos Aires, Argentina

    PubMed Central

    Carballo-Diéguez, Alex; Balan, Ivan; Marone, Rubén; Pando, María A.; Dolezal, Curtis; Barreda, Victoria; Leu, Cheng-Shiun; Ávila, María Mercedes

    2011-01-01

    Background Prior research focusing on men who have sex with men (MSM) conducted in Buenos Aires, Argentina, used convenience samples that included mainly gay identified men. To increase MSM sample representativeness, we used Respondent Driven Sampling (RDS) for the first time in Argentina. Using RDS, under certain specified conditions, the observed estimates for the percentage of the population with a specific trait are asymptotically unbiased. We describe, the diversity of the recruited sample, from the point of view of sexual orientation, and contrast the different subgroups in terms of their HIV sexual risk behavior. Methodology 500 MSM were recruited using RDS. Behavioral data were collected through face-to-face interviews and Web-based CASI. Conclusion In contrast with prior studies, RDS generated a very diverse sample of MSM from a sexual identity perspective. Only 24.5% of participants identified as gay; 36.2% identified as bisexual, 21.9% as heterosexual, and 17.4% were grouped as “other.” Gay and non-gay identified MSM differed significantly in their sexual behavior, the former having higher numbers of partners, more frequent sexual contacts and less frequency of condom use. One third of the men (gay, 3%; bisexual, 34%, heterosexual, 51%; other, 49%) reported having had sex with men, women and transvestites in the two months prior to the interview. This population requires further study and, potentially, HIV prevention strategies tailored to such diversity of partnerships. Our results highlight the potential effectiveness of using RDS to reach non-gay identified MSM. They also present lessons learned in the implementation of RDS to recruit MSM concerning both the importance and limitations of formative work, the need to tailor incentives to circumstances of the less affluent potential participants, the need to prevent masking, and the challenge of assessing network size. PMID:22102896

  15. Referred Air Method 25E: Determination of a Vapor Phase Organic Concentration in Waste Samples

    EPA Pesticide Factsheets

    This method is applicable for determining the vapor pressure of waste. The headspace vapor of the sample is analyzed for carbon content by a headspace analyzer, which uses a flame ionization detector (FID).

  16. Validation of heat transfer, thermal decomposition, and container pressurization of polyurethane foam using mean value and Latin hypercube sampling approaches

    SciTech Connect

    Scott, Sarah N.; Dodd, Amanda B.; Larsen, Marvin E.; Suo-Anttila, Jill M.; Erickson, Ken L.

    2014-12-09

    In this study, polymer foam encapsulants provide mechanical, electrical, and thermal isolation in engineered systems. It can be advantageous to surround objects of interest, such as electronics, with foams in a hermetically sealed container in order to protect them from hostile environments or from accidents such as fire. In fire environments, gas pressure from thermal decomposition of foams can cause mechanical failure of sealed systems. In this work, a detailed uncertainty quantification study of polymeric methylene diisocyanate (PMDI)-polyether-polyol based polyurethane foam is presented and compared to experimental results to assess the validity of a 3-D finite element model of the heat transfer and degradation processes. In this series of experiments, 320 kg/m3 PMDI foam in a 0.2 L sealed steel container is heated to 1,073 K at a rate of 150 K/min. The experiment ends when the can breaches due to the buildup of pressure. The temperature at key location is monitored as well as the internal pressure of the can. Both experimental uncertainty and computational uncertainty are examined and compared. The mean value method (MV) and Latin hypercube sampling (LHS) approach are used to propagate the uncertainty through the model. The results of the both the MV method and the LHS approach show that while the model generally can predict the temperature at given locations in the system, it is less successful at predicting the pressure response. Also, these two approaches for propagating uncertainty agree with each other, the importance of each input parameter on the simulation results is also investigated, showing that for the temperature response the conductivity of the steel container and the effective conductivity of the foam, are the most important parameters. For the pressure response, the activation energy, effective conductivity, and specific heat are most important. The comparison to experiments and the identification of the drivers of uncertainty allow

  17. Validation of heat transfer, thermal decomposition, and container pressurization of polyurethane foam using mean value and Latin hypercube sampling approaches

    DOE PAGES

    Scott, Sarah N.; Dodd, Amanda B.; Larsen, Marvin E.; ...

    2014-12-09

    In this study, polymer foam encapsulants provide mechanical, electrical, and thermal isolation in engineered systems. It can be advantageous to surround objects of interest, such as electronics, with foams in a hermetically sealed container in order to protect them from hostile environments or from accidents such as fire. In fire environments, gas pressure from thermal decomposition of foams can cause mechanical failure of sealed systems. In this work, a detailed uncertainty quantification study of polymeric methylene diisocyanate (PMDI)-polyether-polyol based polyurethane foam is presented and compared to experimental results to assess the validity of a 3-D finite element model of themore » heat transfer and degradation processes. In this series of experiments, 320 kg/m3 PMDI foam in a 0.2 L sealed steel container is heated to 1,073 K at a rate of 150 K/min. The experiment ends when the can breaches due to the buildup of pressure. The temperature at key location is monitored as well as the internal pressure of the can. Both experimental uncertainty and computational uncertainty are examined and compared. The mean value method (MV) and Latin hypercube sampling (LHS) approach are used to propagate the uncertainty through the model. The results of the both the MV method and the LHS approach show that while the model generally can predict the temperature at given locations in the system, it is less successful at predicting the pressure response. Also, these two approaches for propagating uncertainty agree with each other, the importance of each input parameter on the simulation results is also investigated, showing that for the temperature response the conductivity of the steel container and the effective conductivity of the foam, are the most important parameters. For the pressure response, the activation energy, effective conductivity, and specific heat are most important. The comparison to experiments and the identification of the drivers of uncertainty allow for

  18. Air-Assisted Liquid Liquid-Microextraction for the Analysis of Fungicides from Environmental Water and Juice Samples.

    PubMed

    Wu, Shiju; Jin, Tingting; Cheng, Jing; Zhou, Hongbin; Cheng, Min

    2015-07-01

    In this work, a rapid method based on air-assisted liquid liquid microextraction (AALLME) was developed for the determination of three fungicides (azoxystrobin, diethofencarb and pyrimethanil) in water and juice samples. A narrow-neck glass tube was made to facilitate collection of the low-density extractant. The mixture of extractant and sample solution is rapidly sucked into a 5-mL glass syringe and then is injected into the narrow-neck glass tube and the procedure is repeated six times. A homogeneous solution was formed and then with the continuous injection of air by a 20-mL glass syringe, phase separation happened and the extractant was collected on the top of the sample solution. No centrifugation separation step was involved. It took only 90 s to complete the pretreatment process. The influence of main factors on the extraction efficiency is studied. Under optimal conditions, enrichment factors for the three fungicides varied from 145 to 178. The limits of detection for azoxystrobin, diethofencarb and pyrimethanil were 0.08, 0.16 and 0.25 µg L(-1), respectively. Reasonable relative recoveries were varied from 72.3 to 108.0%. And satisfactory intra-assay (5.3-6.2%, n = 6) and inter-assay (6.8-9.3%, n = 6) precision illustrated good performance of the analytical procedure.

  19. A device for sampling and determination of total particulate mercury in ambient air.

    PubMed

    Lu, J Y; Schroeder, W H; Berg, T; Munthe, J; Schneeberger, D; Schaedlich, F

    1998-06-01

    A miniaturized device, which serves as both particulate trap and pyrolyzer for airborne particulate mercury species, is described. It has been used in combination with amalgamation/thermal desorption/cold vapor atomic fluorescence spectrometry detection for the determination of total particulate mercury (TPM) associated with atmospheric aerosols. A standard reference material (SRM 1633b, NIST) has been used for validating of the pyrolysis technique, and a relative error smaller than 3% has been obtained. Contrary to most methods currently employed, this new technique does not require any sample preparation (e.g., extraction/digestion), no manual sample transfer or sample handling, and no addition of chemicals or reagents. Hence the risk of contamination is low. The time for complete analysis is less than 10 min per sample. The concentrations of TPM determined in metropolitan Toronto ranged from 3 to 91 pg m(-)(3) with standard deviations of <±2 pg m(-)(3) for simultaneous sets of four samples. These atmospheric TPM concentration values fall within the range reported in the literature. Good agreement was obtained by the three methods compared in a field study at Ny-Ålesund (78°54'N, 11°53'E), Svalbard. The elevated values of TPM concentrations obtained using the method developed in this work may arise from the Arctic springtime conversion of atmospheric mercury from gas-phase to particulate-phase Hg species.

  20. Monte-Carlo simulation of nano-collected current from a silicon sample containing a linear arrangement of uncapped nanocrystals

    SciTech Connect

    Ledra, Mohammed; El Hdiy, Abdelillah

    2015-09-21

    A Monte-Carlo simulation algorithm is used to study electron beam induced current in an intrinsic silicon sample, which contains at its surface a linear arrangement of uncapped nanocrystals positioned in the irradiation trajectory around the hemispherical collecting nano-contact. The induced current is generated by the use of electron beam energy of 5 keV in a perpendicular configuration. Each nanocrystal is considered as a recombination center, and the surface recombination velocity at the free surface is taken to be zero. It is shown that the induced current is affected by the distance separating each nanocrystal from the nano-contact. An increase of this separation distance translates to a decrease of the nanocrystals density and an increase of the minority carrier diffusion length. The results reveal a threshold separation distance from which nanocrystals have no more effect on the collection efficiency, and the diffusion length reaches the value obtained in the absence of nanocrystals. A cross-section characterizing the nano-contact ability to trap carriers was determined.

  1. Test plan for headspace gas sampling of remote-handled transuranic waste containers at Los Alamos National Laboratory

    SciTech Connect

    Field, L.R.; Villarreal, R.

    1998-02-24

    Seventeen remote-handled (RH) transuranic (TRU) waste canisters currently are stored in vertical, underground shafts at Technical Area (TA)-54, Area G, at Los Alamos National Laboratory (LANL). These 17 RH TRU waste canisters are destined to be shipped to the Waste Isolation Pilot Plant (WIPP) for permanent disposal in the geologic repository. As the RH TRU canister is likely to be the final payload container prior to placement into the 72-B cask and shipment to the WIPP, these waste canisters provide a unique opportunity to ascertain representative flammable gas concentrations in packaged RH-TRU waste. Hydrogen, which is produced by the radiolytic decomposition of hydrogenous constituents in the waste matrix, is the primary flammable gas of concern with RH TRU waste. The primary objectives of the experiment that is described by this test plan are to sample and analyze the waste canister headspace gases to determine the concentration of hydrogen in the headspace gas and to calculate the hydrogen gas generation rate for comparison to the applicable maximum allowable hydrogen generation rate (mole/sec) limits. It is a goal of this experiment to determine the headspace gas concentrations of other gases (e.g., oxygen, nitrogen, carbon dioxide, carbon monoxide, and volatile organic compounds (VOCs) with molecular weights less than 60 g/mole) that are produced by radiolysis or present when the waste was packaged. Additionally, the temperature, pressure, and flow rate of the headspace gas will be measured.

  2. Auditing of sampling methods for air toxics at coal-fired power plants

    SciTech Connect

    Agbede, R.O.; Clements, J.L.; Grunebach, M.G.

    1995-11-01

    Advanced Technology Systems, Inc. (ATS) with subcontract assistance from international Technology Corporation (IT) has provided external audit activities for Phase II of the Department of Energy-Pittsburgh Energy Technology Center`s air emission test program. The objective of the audits is to help ensure that the data obtained from the emission tests are precise, accurate, representative, scientifically sound and legally defensible. This paper presents the criteria that were used to perform the external audits of the emission test program. It also describes the approach used by ATS and It in performing their audits. Examples of findings of the audits along with the actions take to correct problems and the subsequent effect of those actions on the test data are presented. The results of audit spikes performed at the Plant 1 test site are also discussed.

  3. Performance assessment of refractory samples in the Los Alamos Controlled Air Incinerator

    SciTech Connect

    Hutchins, D.A.; Borduin, L.C.; Koenig, R.A.; Vavruska, J.S.; Warner, C.L.

    1986-01-01

    A refractory evaluation project was initiated in 1979 to study the performance of six selected refractory materials within the Los Alamos Controlled Air Incinerator (CAI). Determining refractory resistance to thermal shock, chemical attack, and plutonium uptake was of particular interest. The experimental refractories were subjected to a variety of waste materials, including transuranic (TRU) contaminated wastes, highly chlorinated compounds and alkaline metal salts of perchlorate, chlorate, nitrate and oxylate, over the six year period of this study. Results of this study to date indicate that the use of high alumina, and possibly specialty plastic refractories, is advisable for the lining of incinerators used for the thermal destruction of diverse chemical compounds. 12 refs., 4 tabs.

  4. STS 129 Return Samples: Assessment of Air Quality aboard the Shuttle (STS-129) and International Space Station (ULF3)

    NASA Technical Reports Server (NTRS)

    James, John T.

    2010-01-01

    Reports on the air quality aboard the Space Shuttle (STS-129), and the International Space station (ULF3). NASA analyzed the grab sample canisters (GSCs) and the formaldehyde badges aboard both locations for carbon monoxide levels. The three surrogates: (sup 13)C-acetone, fluorobenzene, and chlorobenzene registered 109, 101, and 109% in the space shuttle and 81, 87, and 55% in the International Space Station (ISS). From these results the atmosphere in both the Space Shuttle and the International Space Station (ISS) was found to be breathable.

  5. Monitoring of ozone precursors in ambient air using pumped and diffusive sampling on the sorbent Carbopack X

    NASA Astrophysics Data System (ADS)

    Quincey, Paul; Butterfield, David; D'Souza, Hansa; Henderson, Malcolm

    EU legislation for ambient ozone concentrations puts a requirement on Member States to monitor a large set of ozone precursor species, mostly hydrocarbons. We describe an investigation into how much of this information is readily available from manual methods used routinely for benzene monitoring in the United Kingdom, using pumped or diffusive sampling of ambient air onto the sorbent Carbopack X, followed by thermal desorption and gas chromatography with a flame ionisation detector. Identifiable peaks were assessed for reliability by comparison with independent automated measurements and emissions inventories. We conclude that 21 of the 29 specified hydrocarbons can be usefully monitored without any change to the methods used.

  6. 6S Return Samples: Assessment of Air Quality in the International Space Station (ISS) Based on Solid Sorbent Air Sampler (SSAS) and Formaldehyde Monitoring Kit (FMK) Analyses

    NASA Technical Reports Server (NTRS)

    James, John T.

    2004-01-01

    The toxicological assessments of SSAS and FMK analytical results are reported. Analytical methods have not changed from earlier reports. Surrogate standard recoveries from the SSAS tubes were 66-76% for 13C-acetone, 85-96% for fluorobenzene, and 73-89% for chlorobenzene. Post-flight flows were far below pre-flight flows and an investigation of the problem revealed that the reduced flow was caused by a leak at the interface of the pump inlet tube and the pump head. This resulted in degradation of pump efficiency. Further investigation showed that the problem occurred before the SSAS was operated on orbit and that use of the post-flight flows yielded consistent and useful results. Recoveries from formaldehyde control badges were 86 to 104%. The two general criteria used to assess air quality are the total-non-methane-volatile organic hydrocarbons (NMVOCs) and the total T-value (minus the CO2 and formaldehyde contributions). The T values will not be reported for these data due to the flow anomaly. Control of atmospheric alcohols is important to the water recovery system engineers, hence total alcohols (including acetone) are also shown for each sample. Octafluoropropane (OFP) is not efficiently trapped by the sorbents used in the SSAS. Because formaldehyde is quantified from sorbent badges, its concentration is also listed separately. These five indices of air quality are summarized.

  7. Instrumental nuclear activation analysis (INAA) characterization of environmental air filter samples.

    PubMed

    Alemón, Ernesto; Herrera, Luis; Ortiz, Elba; Longoria, L C Luis C

    2004-06-01

    Nuclear techniques have been used in quantitations of environmental pollutants, and instrumental neutron activation analysis (INAA) has turned out to be particularly useful in the analysis of airborne suspended particles. This work describes the INAA characterization of the particulate material in the environmental samples obtained in a monitoring campaign in Mexico City's Metropolitan Area. As the types of the irradiation facilities and gamma-ray detection system impose some limitations on the possibilities of INAA analysis, the actual experimental conditions at Gamma Spectroscopy Laboratory, where the analysis was performed, had been assessed. The facilities had been found suitable for the analysis of samples from this campaign, in which 22 elements were determined.

  8. STS 133 Return Samples: Air Quality Aboard Shuttle (STS-133) and International Space Station (ULFS)

    NASA Technical Reports Server (NTRS)

    James, John T.

    2011-01-01

    The toxicological assessments of 2 canisters (mini-GSC or GSCs) from the Shuttle are reported. Analytical methods have not changed from earlier reports. The percent recoveries of the 3 surrogates (C-13-acetone, fluorobenzene, and chlorobenzene) from the 2 Shuttle GSCs averaged 86, 100, and 87, respectively. Based on the end-of-mission sample, the Shuttle atmosphere was acceptable for human respiration.

  9. The classification of the patients with pulmonary diseases using breath air samples spectral analysis

    NASA Astrophysics Data System (ADS)

    Kistenev, Yury V.; Borisov, Alexey V.; Kuzmin, Dmitry A.; Bulanova, Anna A.

    2016-08-01

    Technique of exhaled breath sampling is discussed. The procedure of wavelength auto-calibration is proposed and tested. Comparison of the experimental data with the model absorption spectra of 5% CO2 is conducted. The classification results of three study groups obtained by using support vector machine and principal component analysis methods are presented.

  10. Assessment of air sampling methods and size distribution of virus-laden aerosols in outbreaks in swine and poultry farms.

    PubMed

    Alonso, Carmen; Raynor, Peter C; Goyal, Sagar; Olson, Bernard A; Alba, Anna; Davies, Peter R; Torremorell, Montserrat

    2017-03-01

    Swine and poultry viruses, such as porcine reproductive and respiratory syndrome virus (PRRSV), porcine epidemic diarrhea virus (PEDV), and highly pathogenic avian influenza virus (HPAIV), are economically important pathogens that can spread via aerosols. The reliability of methods for quantifying particle-associated viruses as well as the size distribution of aerosolized particles bearing these viruses under field conditions are not well documented. We compared the performance of 2 size-differentiating air samplers in disease outbreaks that occurred in swine and poultry facilities. Both air samplers allowed quantification of particles by size, and measured concentrations of PRRSV, PEDV, and HPAIV stratified by particle size both within and outside swine and poultry facilities. All 3 viruses were detectable in association with aerosolized particles. Proportions of positive sampling events were 69% for PEDV, 61% for HPAIV, and 8% for PRRSV. The highest virus concentrations were found with PEDV, followed by HPAIV and PRRSV. Both air collectors performed equally for the detection of total virus concentration. For all 3 viruses, higher numbers of RNA copies were associated with larger particles; however, a bimodal distribution of particles was observed in the case of PEDV and HPAIV.

  11. Development of More Cost-Effective Methods for Long-Term Monitoring of Soil Vapor Intrusion to Indoor Air Using Quantitative Passive Diffusive-Adsorptive Sampling Techniques

    DTIC Science & Technology

    2015-05-01

    ER-200830) Development of More Cost-Effective Methods for Long-Term Monitoring of Soil Vapor Intrusion to Indoor Air Using...Methods for Long-Term Monitoring of Soil Vapor Intrusion to Indoor Air Using Quantitative Passive Diffusive-Adsorptive Sampling Techniques W912HQ-08-C...volatile organic compounds (VOCs) at sites with potential human health risks. These risks were attributable to subsurface vapor intrusion to indoor air by

  12. Chamber validation of a passive air sampling device for measuring ambient VOCs at subzero temperatures

    SciTech Connect

    Gagner, R.V.; Hrudey, S.E.

    1997-12-31

    An evaluation was made of the performance of the 3M Organic Vapor Monitor No. 3500 through experiments conducted under permeation tube generated atmospheres in a controlled chamber environment. A range of typical ambient benzene and toluene concentrations were produced in the chamber to test the consistency of the sampling rate under different exposure levels. All tests were repeated at room temperature, and under subzero Celsius conditions to determine the effect of lowered temperatures on the performance of the badge. As expected, relatively low concentrations of benzene and toluene produced small incremental increases in analyte above the background levels inherent to the badge and analytical methods resulting in a loss of method precision. The badge sampling rate was not significantly affected by decreases in temperature to minus fifteen degrees Celsius. This finding was not consistent with the theoretically-based temperature correction factors identified in the product literature.

  13. Linear Regression Modeling of Selected Analytes from the Balad Air Sampling Program

    DTIC Science & Technology

    2012-04-05

    Spearman correlation coefficient – Option is used in the IBM SPSS® Statistics V20 program when comparing two variables (weather – analyte...The positive Spearman correlation coefficient value (0.598) indicates analyte concentration for benzo[a]pyrene increased during the four sampling...Cadmium The negative Spearman correlation coefficient value (-0.318) indicates that the analyte concentration of cadmium decreased over the four

  14. Air University Sampling and Surveying Handbook: Guidelines for Planning, Organizing, and Conducting Surveys

    DTIC Science & Technology

    1996-01-01

    Publication Pending (1993). Altemeyer, R. A. (1970). Adverbs and Intervals: A Study of Likert Scales. American Psychological Association, Proceedings of...1959). Adverbs As Multipliers. Psychological Review, 66, pp 27-44. Cochran, W. G. (1963) Sampling Techniques. New York: Wiley and Sons, Inc. Deming...Auditor, Vol. 28, No. 6, pp 49-52. Selltiz, Claire, Marie Jahoda, Morton Deutsch , and Stuart W. Cook (1963). Research Methods in Social Relations

  15. Sampling biases in datasets of historical mean air temperature over land.

    PubMed

    Wang, Kaicun

    2014-04-10

    Global mean surface air temperature (Ta) has been reported to have risen by 0.74°C over the last 100 years. However, the definition of mean Ta is still a subject of debate. The most defensible definition might be the integral of the continuous temperature measurements over a day (Td0). However, for technological and historical reasons, mean Ta over land have been taken to be the average of the daily maximum and minimum temperature measurements (Td1). All existing principal global temperature analyses over land rely heavily on Td1. Here, I make a first quantitative assessment of the bias in the use of Td1 to estimate trends of mean Ta using hourly Ta observations at 5600 globally distributed weather stations from the 1970s to 2013. I find that the use of Td1 has a negligible impact on the global mean warming rate. However, the trend of Td1 has a substantial bias at regional and local scales, with a root mean square error of over 25% at 5° × 5° grids. Therefore, caution should be taken when using mean Ta datasets based on Td1 to examine high resolution details of warming trends.

  16. Sampling Biases in Datasets of Historical Mean Air Temperature over Land

    NASA Astrophysics Data System (ADS)

    Wang, Kaicun

    2014-04-01

    Global mean surface air temperature (Ta) has been reported to have risen by 0.74°C over the last 100 years. However, the definition of mean Ta is still a subject of debate. The most defensible definition might be the integral of the continuous temperature measurements over a day (Td0). However, for technological and historical reasons, mean Ta over land have been taken to be the average of the daily maximum and minimum temperature measurements (Td1). All existing principal global temperature analyses over land rely heavily on Td1. Here, I make a first quantitative assessment of the bias in the use of Td1 to estimate trends of mean Ta using hourly Ta observations at 5600 globally distributed weather stations from the 1970s to 2013. I find that the use of Td1 has a negligible impact on the global mean warming rate. However, the trend of Td1 has a substantial bias at regional and local scales, with a root mean square error of over 25% at 5° × 5° grids. Therefore, caution should be taken when using mean Ta datasets based on Td1 to examine high resolution details of warming trends.

  17. Development of automated preparation system for isotopocule analysis of N2O in various air samples

    NASA Astrophysics Data System (ADS)

    Toyoda, Sakae; Yoshida, Naohiro

    2016-05-01

    Nitrous oxide (N2O), an increasingly abundant greenhouse gas in the atmosphere, is the most important stratospheric ozone-depleting gas of this century. Natural abundance ratios of isotopocules of N2O, NNO molecules substituted with stable isotopes of nitrogen and oxygen, are a promising index of various sources or production pathways of N2O and of its sink or decomposition pathways. Several automated methods have been reported to improve the analytical precision for the isotopocule ratio of atmospheric N2O and to reduce the labor necessary for complicated sample preparation procedures related to mass spectrometric analysis. However, no method accommodates flask samples with limited volume or pressure. Here we present an automated preconcentration system which offers flexibility with respect to the available gas volume, pressure, and N2O concentration. The shortest processing time for a single analysis of typical atmospheric sample is 40 min. Precision values of isotopocule ratio analysis are < 0.1 ‰ for δ15Nbulk (average abundances of 14N15N16O and 15N14N16O relative to 14N14N16O), < 0.2 ‰ for δ18O (relative abundance of 14N14N18O), and < 0.5 ‰ for site preference (SP; difference between relative abundance of 14N15N16O and 15N14N16O). This precision is comparable to that of other automated systems, but better than that of our previously reported manual measurement system.

  18. Lessons from UNSCOM and IAEA regarding remote monitoring and air sampling

    SciTech Connect

    Dupree, S.A.

    1996-01-01

    In 1991, at the direction of the United Nations Security Council, UNSCOM and IAEA developed plans for On-going Monitoring and Verification (OMV) in Iraq. The plans were accepted by the Security Council and remote monitoring and atmospheric sampling equipment has been installed at selected sites in Iraq. The remote monitoring equipment consists of video cameras and sensors positioned to observe equipment or activities at sites that could be used to support the development or manufacture of weapons of mass destruction, or long-range missiles. The atmospheric sampling equipment provides unattended collection of chemical samples from sites that could be used to support the development or manufacture of chemical weapon agents. To support OMV in Iraq, UNSCOM has established the Baghdad Monitoring and Verification Centre. Imagery from the remote monitoring cameras can be accessed in near-real time from the Centre through RIF communication links with the monitored sites. The OMV program in Iraq has implications for international cooperative monitoring in both global and regional contexts. However, monitoring systems such as those used in Iraq are not sufficient, in and of themselves, to guarantee the absence of prohibited activities. Such systems cannot replace on-site inspections by competent, trained inspectors. However, monitoring similar to that used in Iraq can contribute to openness and confidence building, to the development of mutual trust, and to the improvement of regional stability.

  19. COMPARISON OF 24H AVERAGE VOC MONITORING RESULTS FOR RESIDENTIAL INDOOR AND OUTDOOR AIR USING CARBOPACK X-FILLED DIFFUSIVE SAMPLERS AND ACTIVE SAMPLING - A PILOT STUDY

    EPA Science Inventory

    Analytical results obtained by thermal desorption GC/MS for 24h diffusive sampling of 11 volatile organic compounds (VOCs) are compared with results of time-averaged active sampling at a known constant flow rate. Air samples were collected with co-located duplicate diffusive samp...

  20. A Model Using Local Weather Data to Determine the Effective Sampling Volume for PCB Congeners Collected on Passive Air Samplers

    PubMed Central

    2016-01-01

    We have developed and evaluated a mathematical model to determine the effective sampling volumes (Veff) of PCBs and similar compounds captured using polyurethane foam passive air samplers (PUF–PAS). We account for the variability in wind speed, air temperature, and equilibrium partitioning over the course of the deployment of the samplers. The model, provided as an annotated Matlab script, predicts the Veff as a function of physical-chemical properties of each compound and meteorology from the closest Integrated Surface Database (ISD) data set obtained through NOAA’s National Centers for Environmental Information (NCEI). The model was developed to be user-friendly, only requiring basic Matlab knowledge. To illustrate the effectiveness of the model, we evaluated three independent data sets of airborne PCBs simultaneously collected using passive and active samplers: at sites in Chicago, Lancaster, UK, and Toronto, Canada. The model provides Veff values comparable to those using depuration compounds and calibration against active samplers, yielding an average congener specific concentration method ratio (active/passive) of 1.1 ± 1.2. We applied the model to PUF–PAS samples collected in Chicago and show that previous methods can underestimate concentrations of PCBs by up to 40%, especially for long deployments, deployments conducted under warming conditions, and compounds with log Koa values less than 8. PMID:26963482

  1. Vortex and air assisted liquid-liquid microextraction as a sample preparation method for high-performed liquid chromatography determinations.

    PubMed

    Hosseini, Mohammad; Heydari, Rouhollah; Alimoradi, Mohammad

    2014-12-01

    A novel, simple and sensitive method based on vortex and air assisted liquid-liquid microextraction (VAALLME) technique coupled with high-performance liquid chromatography (HPLC) has been developed for quantitative analysis of β-naphthol, naphthalene and anthracene as model analytes. Unlike the dispersive liquid-liquid microextraction (DLLME), dispersive solvent and centrifuging step were eliminated in proposed technique. In this technique, extraction solvent was dispersed into the aqueous sample solution by using vortex. Phase separation was achieved via motion of air bubbles from the bottom to top of the extraction tube, which promoted the analytes transfer into the supernatant organic phase. Influential parameters on the extraction efficiency such as type and volume of extraction solvent, salt type and its concentration, vortex and aeration times, and sample pH were evaluated and optimized. The calibration curves showed good linearity (r(2)>0.9947) and precision (RSD<5.0%) in the working concentration ranges. The limit of detection (LOD) for β-naphthol, naphthalene and anthracene were 10, 5.0 and 0.5 ng mL(-1), respectively. The recoveries were in the range of 97.0-102.0% with RSD values ranging from 2.2 to 5.2%.

  2. Halocarbons, alkyl nitrates, and nonmethane hydrocarbons quantified from surface air and water samples in the Gulf of Maine during NEAQS

    NASA Astrophysics Data System (ADS)

    Haase, K. B.; Harlow, A.; Sive, B. C.; Wingenter, O. W.

    2003-12-01

    During the New England Air Quality Study (NEAQS) campaign, July-August 2002, natural and anthropogenic halocarbons, alkyl nitrates, and nonmethane hydrocarbons (NMHCs) in surface air and water samples were quantified in situ using gas chromatography with flame ionization and electron capture detection aboard the NOAA R/V Ronald H. Brown. The cruise focused on an area in the Gulf of Maine, south of Portsmouth Harbor, near the Isle of Shoals, and in the Boston Harbor area. Between Cape Ann and Newburyport, saturation anomalies for anthropogenic halocarbons of 100% for CFC-113, 140% for H-1211, 40% for methyl chloroform, and 15% for carbon tetrachloride were observed. Throughout the cruise, subsequent high levels of these compounds were found in the area. The findings suggest that there are local anthropogenic sources of these gases, which are draining into the Gulf of Maine from local rivers, harbors, or estuaries. Elevated level of methyl bromide, methyl iodide, bromoform, and chloroform were measured near the coast, and decreased with increasing distance. The distributions of the NMHCs were similar to the naturally produced marine halocarbons, suggesting similar sources. Supersaturation of alkyl nitrates were observed indicating an oceanic source of methyl nitrate, i-propyl nitrate, n-propyl nitrate, and 2-butyl nitrate, with the later three compounds reported here in ocean water samples for the first time.

  3. Health risk assessment of exposure to polybrominated diphenyl ethers (PBDEs) contained in residential air particulate and dust in Guangzhou and Hong Kong

    NASA Astrophysics Data System (ADS)

    Wang, Wei; Zheng, Jinshu; Chan, Chuen-Yu; Huang, Min-juan; Cheung, Kwai Chung; Wong, Ming Hung

    2014-06-01

    Polybrominated diphenyl ethers (PBDEs) were measured in air particulate PM2.5 (less than 2.5 μm), TSP (Total Suspend Particle) and dust samples from different households of two major urban centers of Pearl River Delta (PRD). ∑PBDEs in PM2.5 of households in Guangzhou (GZ) (52.9-2.03 × 103 pg m-3 mean 239 pg m-3) were significantly higher than Hong Kong (HK) (0.25-160 pg m-3, mean 43.8 pg m-3). Higher ∑PBDEs occurred in indoor TSP, ranging between 117 and 1.14 × 103 pg m-3, with a median of 333 pg m-3. BDE-209 was the largest contributor to PBDEs contained in household dust, PM2.5 and TSP samples of GZ. Among the particles in household environment, PM2.5 accumulated the highest PBDEs, especially BDE-209. The constant Cparticle/Cdust values suggested that sorption is the dominant mechanism through which PBDEs are associated with settled dust and airborne particles. PBDEs were fairly uniform from urban sites to suburban sites, indicating the predominant indoor sources of PBDEs. Compared with indoor PM2.5, indoor dust ingestion made an important contribution of particle associated PBDEs exposure for adults (25 years old) and toddlers (1-2 years old). Non-dietary exposure dominated total PBDEs exposure, accounting for 91.8-99.0% exposure dose for toddlers and 45.1-82.2% for adults. Dust ingestion (69.3-96.1%) was the predominant PBDEs exposure route for toddlers.

  4. Characterization of the bacterial and fungal microbiome in indoor dust and outdoor air samples: a pilot study.

    PubMed

    Hanson, Blake; Zhou, Yanjiao; Bautista, Eddy J; Urch, Bruce; Speck, Mary; Silverman, Frances; Muilenberg, Michael; Phipatanakul, Wanda; Weinstock, George; Sodergren, Erica; Gold, Diane R; Sordillo, Joanne E

    2016-06-15

    Environmental microbes have been associated with both protective and adverse health effects in children and adults. Epidemiological studies often rely on broad biomarkers of microbial exposure (i.e. endotoxin, 1 → 3-beta-d-glucan), but fail to identify the taxonomic composition of the microbial community. Our aim was to characterize the bacterial and fungal microbiome in different types of environmental samples collected in studies of human health effects. We determined the composition of microbial communities present in home, school and outdoor air samples by amplifying and sequencing regions of rRNA genes from bacteria (16S) and fungi (18S and ITS). Samples for this pilot study included indoor settled dust (from both a Boston area birth cohort study on Home Allergens and Asthma (HAA) (n = 12) and a study of school exposures and asthma symptoms (SICAS) (n = 1)), as well as fine and coarse concentrated outdoor ambient particulate (CAP) samples (n = 9). Sequencing of amplified 16S, 18S, and ITS regions was performed on the Roche-454 Life Sciences Titanium pyrosequencing platform. Indoor dust samples were dominated by Gram-positive bacteria (Firmicutes and Actinobacteria); the most abundant bacterial genera were those related to human flora (Streptococcus, Staphylococcus, Corynebacterium and Lactobacillus). Outdoor CAPs were dominated by Gram-negative Proteobacteria from water and soil sources, in particular the genera Acidovorax, and Brevundimonas (which were present at very low levels or entirely absent in indoor dust). Phylum-level fungal distributions identified by 18S or ITS regions showed very similar findings: a predominance of Ascomycota in indoor dust and Basidiomycota in outdoor CAPs. ITS sequencing of fungal genera in indoor dust showed significant proportions of Aureobasidium and Leptosphaerulina along with some contribution from Cryptococcus, Epicoccum, Aspergillus and the human commensal Malassezia. ITS sequencing detected more than 70 fungal genera

  5. Development of a sampling and analytical method for 2,2-dichloro-1,1,1-trifluoroethane in workplace air.

    PubMed

    Shin, Yong Chul; Yi, Gwang Yong; Kim, Yangho; Paik, Nam Won

    2002-01-01

    The use of 2,2-dichloro-1,1,1-trifluoroethane (compound number: HCFC-123) is growing in industry as a substitute for ozone-depleting chlorofluorocarbons (CFCs). Recently, liver-related illnesses have been reported from industries handling HCFC-123. However, information on worker exposure to the material is limited, and an acceptable sampling/analytical method is not available. The aim of this study was to develop a widely applicable sampling and analytical method to determine worker exposures to airborne HCFC-123 and to evaluate the performance of the method. A solid sorbent tube, containing two sections (400 mg in the front and 200 mg in the back) of activated coconut-shell charcoal was chosen for sampling airborne HCFC-123 vapor. The breakthrough volumes were 13.6 L at 3597 +/- 210.1 ppm (with a sampling airflow rate of 0.046 L/min) and 17.0 L at 1841 +/- 4.5 ppm (with sampling airflow rate of 0.046-0.050 L/min). Samples of HCFC-123 in the charcoal tube were stable for 7 days either at room temperature or in a refrigerator and a migration occurred within 14 days at room temperature. It is recommended that the HCFC-123 sample in activated charcoal tubes be stored either at room temperature or in a refrigerator and be analyzed within 7 days. The HCFC-123 in the charcoal tubes was desorbed into dichloromethane and analyzed using gas chromatography/ flame ionization detection. The limit of detection was 0.23 mg/sample, and the average desorption efficiency was 99.0%. The total coefficient of variation was 0.060, and the method accuracy was 16.6%. In conclusion, the performance of the sampling and analytical method developed for the determination of airborne HCFC-123 concentrations was acceptable to the NIOSH sampling and analytical criteria.

  6. Surveillance of a Ventilated Rack System for Corynebacterium bovis by Sampling Exhaust-Air Manifolds.

    PubMed

    Manuel, Christopher A; Pugazhenthi, Umarani; Leszczynski, Jori K

    2016-01-01

    Corynebacterium bovis causes an opportunistic infection of nude (Foxn1, nu/nu) mice, leading to nude mouse hyperkeratotic dermatitis (scaly skin disease). Enzootic in many nude mouse colonies, C. bovis spreads rapidly to naive nude mice, despite modern husbandry practices, and is very difficult to eradicate. To facilitate rapid detection in support of eradication efforts, we investigated a surveillance method based on quantitative real-time PCR (qPCR) evaluation of swabs collected from the horizontal exhaust manifold (HEM) of an IVC rack system. We first evaluated the efficacy of rack sanitation methods for removing C. bovis DNA from the HEM of racks housing endemic colonies of infected nude mice. Pressurized water used to flush the racks' air exhaust system followed by a standard rack-washer cycle was ineffective in eliminating C. bovis DNA. Only after autoclaving did all sanitized racks test negative for C. bovis DNA. We then measured the effects of stage of infection (early or established), cage density, and cage location on the rack on time-to-detection at the HEM. Stage of infection significantly affected time-to-detection, independent of cage location. Early infections required 7.3 ± 1.2 d whereas established infections required 1 ± 0 d for detection of C. bovis at the HEM. Cage density influenced the quantity of C. bovis DNA detected but not time-to-detection. The location of the cage on the rack affected the time-to-detection only during early C. bovis infections. We suggest that qPCR swabs of HEM are useful during the routine surveillance of nude mouse colonies for C. bovis infection.

  7. Surveillance of a Ventilated Rack System for Corynebacterium bovis by Sampling Exhaust-Air Manifolds

    PubMed Central

    Manuel, Christopher A; Pugazhenthi, Umarani; Leszczynski, Jori K

    2016-01-01

    Corynebacterium bovis causes an opportunistic infection of nude (Foxn1, nu/nu) mice, leading to nude mouse hyperkeratotic dermatitis (scaly skin disease). Enzootic in many nude mouse colonies, C. bovis spreads rapidly to naive nude mice, despite modern husbandry practices, and is very difficult to eradicate. To facilitate rapid detection in support of eradication efforts, we investigated a surveillance method based on quantitative real-time PCR (qPCR) evaluation of swabs collected from the horizontal exhaust manifold (HEM) of an IVC rack system. We first evaluated the efficacy of rack sanitation methods for removing C. bovis DNA from the HEM of racks housing endemic colonies of infected nude mice. Pressurized water used to flush the racks’ air exhaust system followed by a standard rack-washer cycle was ineffective in eliminating C. bovis DNA. Only after autoclaving did all sanitized racks test negative for C. bovis DNA. We then measured the effects of stage of infection (early or established), cage density, and cage location on the rack on time-to-detection at the HEM. Stage of infection significantly affected time-to-detection, independent of cage location. Early infections required 7.3 ± 1.2 d whereas established infections required 1 ± 0 d for detection of C. bovis at the HEM. Cage density influenced the quantity of C. bovis DNA detected but not time-to-detection. The location of the cage on the rack affected the time-to-detection only during early C. bovis infections. We suggest that qPCR swabs of HEM are useful during the routine surveillance of nude mouse colonies for C. bovis infection. PMID:26817981

  8. Detection of Bacillus anthracis DNA in Complex Soil and Air Samples Using Next-Generation Sequencing

    PubMed Central

    Be, Nicholas A.; Thissen, James B.; Gardner, Shea N.; McLoughlin, Kevin S.; Fofanov, Viacheslav Y.; Koshinsky, Heather; Ellingson, Sally R.; Brettin, Thomas S.; Jackson, Paul J.; Jaing, Crystal J.

    2013-01-01

    Bacillus anthracis is the potentially lethal etiologic agent of anthrax disease, and is a significant concern in the realm of biodefense. One of the cornerstones of an effective biodefense strategy is the ability to detect infectious agents with a high degree of sensitivity and specificity in the context of a complex sample background. The nature of the B. anthracis genome, however, renders specific detection difficult, due to close homology with B. cereus and B. thuringiensis. We therefore elected to determine the efficacy of next-generation sequencing analysis and microarrays for detection of B. anthracis in an environmental background. We applied next-generation sequencing to titrated genome copy numbers of B. anthracis in the presence of background nucleic acid extracted from aerosol and soil samples. We found next-generation sequencing to be capable of detecting as few as 10 genomic equivalents of B. anthracis DNA per nanogram of background nucleic acid. Detection was accomplished by mapping reads to either a defined subset of reference genomes or to the full GenBank database. Moreover, sequence data obtained from B. anthracis could be reliably distinguished from sequence data mapping to either B. cereus or B. thuringiensis. We also demonstrated the efficacy of a microbial census microarray in detecting B. anthracis in the same samples, representing a cost-effective and high-throughput approach, complementary to next-generation sequencing. Our results, in combination with the capacity of sequencing for providing insights into the genomic characteristics of complex and novel organisms, suggest that these platforms should be considered important components of a biosurveillance strategy. PMID:24039948

  9. Soyuz 7 Return Samples: Assessment of Air Quality Aboard the International Space Station

    NASA Technical Reports Server (NTRS)

    James, John T.

    2004-01-01

    The toxicological assessments of one grab sample canister (GSC), 6 dual sorbent tubes (DSTs), and 20 formaldehyde badges returned aboard Soyuz 7 are reported. Analytical methods have not changed from earlier reports. Surrogate standard recoveries from the GSC were 84-89%. The recoveries of the less volatile surrogates from the DSTs were 87 to 112%; however, 13C-acetone was only recovered at 53-59%. Formaldehyde recoveries from 2 lab controls were 87 and 95%; trip controls were not returned to ground.

  10. Assessment of Air Quality in the Shuttle and International Space Station (ISS) Based on Samples Returned by STS-102 at the Conclusion of 5A.1

    NASA Technical Reports Server (NTRS)

    James, John T.

    2001-01-01

    The toxicological assessment of air samples returned at the end of the STS-102 (5A.1) flight to the ISS is reported. ISS air samples were taken in late February 2001 from the Service Module, FGB, and U.S. Laboratory using grab sample canisters (GSCs) and/or formaldehyde badges . A "first-entry" sample of the multipurpose logistics module (MPLM) atmosphere was taken with a GSC, and preflight and end-of-mission samples were obtained from Discovery using GSCs. Analytical methods have not changed from earlier reports, and all quality control measures were met for the data presented herein. The two general criteria used to assess air quality are the total-non-methane-volatile organic hydrocarbons (NMVOCs) and the total T-value (minus the CO2 contribution). Control of atmospheric alcohols is important to the water recovery system engineers, hence total alcohols were also assessed in each sample. Formaldehyde is quantified separately.

  11. 7 CFR 42.110 - Sampling plans for tightened condition of container inspection; Tables II and II-A.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE COMMODITY STANDARDS AND STANDARD CONTAINER REGULATIONS STANDARDS FOR CONDITION OF FOOD...

  12. Gas chromatography/mass spectrometry methods applied for the analysis of a Round Robin sample containing materials present in samples of works of art

    NASA Astrophysics Data System (ADS)

    van Keulen, Henk

    2009-07-01

    The Users' Group for Mass Spectrometry and Chromatography (MaSC) was established as a discussion forum for scientists involved in the study of artworks and cultural artefacts who wish to exchange information regarding sampling strategies and protocols, preparation of samples, chromatographic and mass spectrometric analysis, data treatment and interpretation of results. Comparing protocols and different approaches to the interpretation of results requires the use of standard reference materials and Round Robin tests. To this end, an artificial, complex Round Robin sample was sent to fifteen laboratories specializing in the analysis of cultural materials. Ten of the participants analyzed the sample and reported their results, which were anonymously discussed at the MaSC meeting in Philadelphia, September 2007. In this paper, the results of the confirming GC/MS analysis of the sample by the author are presented and compared with the results of the participants. The confirming analysis was performed with thermally assisted hydrolysis and methylation GC/MS in combination with pyrolysis, and by a combined method for the analysis of proteins and carbohydrates. A number of different instrumental setups and methods were used by the Round Robin participants. The results show that stepwise extraction followed by different types of derivatization is a successful approach for the analysis and identification of complex samples. A disadvantage is the need for relatively large samples, which are not always available in practice. Pyrolysis with or without tetramethylammonium hydroxide (TMAH) or hexamethyldisilazane (HMDS) was used by four of the participants. The results show that thermally assisted hydrolysis and methylation GC/MS in combination with pyrolysis is a powerful technique for the analysis of multi-component samples. The presence of gums and proteins can be indicated. Synthetic resins such as acrylics can also be analyzed in combination with the traditional binders and

  13. Development of a unique multi-contaminant air sampling device for a childhood asthma cohort in an agricultural environment†

    PubMed Central

    Fitzpatrick, Cole F.; Loftus, Christine T.; Yost, Michael G.; Tchong-French, Maria; Karr, Catherine J.

    2016-01-01

    This research describes the design, deployment, performance, and acceptability of a novel outdoor active air sampler to provide simultaneous measurements of multiple contaminants at timed intervals for the Aggravating Factors of Asthma in Rural Environment (AFARE) study—a longitudinal cohort of 50 children in Yakima Valley, Washington. The sampler was constructed of multiple sampling media connected to individual critical orifices and a rotary vane vacuum pump. It was connected to a timed control valve system to collect 24 hours samples every six days over 18 months. We describe a spatially representative approach with both quantitative and qualitative location criteria to deploy a network of 14 devices at participant residences in a rural region (20 × 60 km). Overall the sampler performed well, as the concurrent mean sample flow rates were within or above the ranges of recommended sampling rates for each exposure metric of interest. Acceptability was high among the study population of Hispanic farmworker participant households. The sampler design may prove useful for future urban and rural community-based studies with aims at collecting multiple contaminant data during specific time periods. PMID:23896655

  14. Protein quantity on the air-solid interface determines degradation rates of human growth hormone in lyophilized samples.

    PubMed

    Xu, Yemin; Grobelny, Pawel; Von Allmen, Alexander; Knudson, Korben; Pikal, Michael; Carpenter, John F; Randolph, Theodore W

    2014-05-01

    Recombinant human growth hormone (rhGH) was lyophilized with various glass-forming stabilizers, employing cycles that incorporated various freezing and annealing procedures to manipulate glass formation kinetics, associated relaxation processes, and glass-specific surface areas (SSAs). The secondary structure in the cake was monitored by infrared and in reconstituted samples by circular dichroism. The rhGH concentrations on the surface of lyophilized powders were determined from electron spectroscopy for chemical analysis. Glass transition temperature (Tg ), SSAs, and water contents were determined immediately after lyophilization. Lyophilized samples were incubated at 323 K for 16 weeks, and the resulting extents of rhGH aggregation, oxidation, and deamidation were determined after rehydration. Water contents and Tg were independent of lyophilization process parameters. Compared with samples lyophilized after rapid freezing, rhGH in samples that had been annealed in frozen solids prior to drying, or annealed in glassy solids after secondary drying retained more native-like protein secondary structure, had a smaller fraction of the protein on the surface of the cake, and exhibited lower levels of degradation during incubation. A simple kinetic model suggested that the differences in the extent of rhGH degradation during storage in the dried state between different formulations and processing methods could largely be ascribed to the associated levels of rhGH at the solid-air interface after lyophilization.

  15. Detection of Erysiphe necator in Air Samples Using the Polymerase Chain Reaction and Species-Specific Primers.

    PubMed

    Falacy, Jennifer S; Grove, Gary G; Mahaffee, Walter F; Galloway, Heather; Glawe, Dean A; Larsen, Richard C; Vandemark, George J

    2007-10-01

    ABSTRACT A polymerase chain reaction (PCR) assay employing species-specific primers was developed to differentiate Erysiphe necator from other powdery mildews common in the northwest United States. DNA was extracted from mycelia, conidia, and/or chasmothecia that were collected from grape leaves with a Burkard cyclonic surface sampler. To differentiate E. necator from other erysiphaeceous fungi, primer pairs Uncin144 and Uncin511 were developed to select unique sequences of the internal transcribed spacer regions of E. necator. Using these primers in PCR amplifications, a 367-bp amplicon specific to E. necator was generated, but no amplicons were generated from other erysiphaceous species collected from 48 disparate hosts representing 26 vascular plant families. The PCR limit of detection was one to five conidia of E. necator placed directly into reaction mixtures or 100 to 250 conidia placed on glass rods coated with silicon grease. During field studies, this PCR assay facilitated the detection of E. necator inoculum in air samples within hours of sample rod collection and prior to disease onset. Amplification of E. necator DNA did not occur when the PCR assay was conducted on vineyard air samples collected while grapes were dormant or during periods when vine growth occurred but E. necator remained dormant. The initial PCR detection of E. necator of the season occurred during seasonal ascospore releases caused by precipitation events between bud burst and the prebloom period during the 3 years of the study. Detection ceased for 7 to 11 days following ascospore release and then resumed several days prior to the observance of microscopic symptoms and signs of powdery mildew in the field. Results of this study represent the initial step toward the goal of incorporating an inoculum availability component into current and future grapevine powdery mildew risk assessment models.

  16. Use of constant wavelength synchronous spectrofluorimetry for identification of polycyclic aromatic hydrocarbons in air particulate samples

    NASA Astrophysics Data System (ADS)

    Sharma, Homdutt; Jain, V. K.; Khan, Zahid H.

    2013-05-01

    We have developed a simple, rapid, inexpensive method for the identification of fluoranthene (Flan), benz(a)anthracene (BaA), benzo(a)pyrene (BaP), benzo(k)fluoranthene (BkF), pyrene (Pyr), benz(ghi)perylene (BghiP) in suspended particulate matter in an urban environment of Delhi. Suspended particulate matter samples of 24 h duration were collected on glass fiber filter papers. Polycyclic aromatic hydrocarbons (PAHs) were extracted from the filter papers using dichloromethane (DCM) and hexane with ultrasonication method. Comparison of the characteristic emission of spectra of PAHs with standard spectra indicated the degree of condensation of aromatic compounds present in investigated mixtures. It was also possible to identify some individual compounds. However, this identification could be more effective with the use of the respective values of Δλ parameter for each particular component of the mixture.

  17. Assessment of Air Quality in the Shuttle and International Space Station (ISS) Based on Samples Returned by STS-105 at the Conclusion of 7A.1

    NASA Technical Reports Server (NTRS)

    James, John T.

    2001-01-01

    The toxicological assessment of air samples returned at the end of the STS-105 (7 A.1) flight to the ISS is reported. ISS air samples were taken in August 2001 from the Service Module, FGB, and U.S. Laboratory using grab sample canisters (GSCs) and/or formaldehyde badges. Preflight and end-of-mission samples were obtained from Discovery using GSCs. Analytical methods have not changed from earlier reports, and surrogate standard recoveries were 64-115%. Pressure tracking indicated no leaks in the canisters.

  18. Analytical results from ground-water sampling using a direct-push technique at the Dover National Test Site, Dover Air Force Base, Delaware, June-July 2001

    USGS Publications Warehouse

    Guertal, William R.; Stewart, Marie; Barbaro, Jeffrey R.; McHale, Timthoy J.

    2004-01-01

    A joint study by the Dover National Test Site and the U.S. Geological Survey was conducted from June 27 through July 18, 2001 to determine the spatial distribution of the gasoline oxygenate additive methyl tert-butyl ether and selected water-quality constituents in the surficial aquifer underlying the Dover National Test Site at Dover Air Force Base, Delaware. The study was conducted to support a planned enhanced bio-remediation demonstration and to assist the Dover National Test Site in identifying possible locations for future methyl tert-butyl ether remediation demonstrations. This report presents the analytical results from ground-water samples collected during the direct-push ground-water sampling study. A direct-push drill rig was used to quickly collect 115 ground-water samples over a large area at varying depths. The ground-water samples and associated quality-control samples were analyzed for volatile organic compounds and methyl tert-butyl ether by the Dover National Test Site analytical laboratory. Volatile organic compounds were above the method reporting limits in 59 of the 115 ground-water samples. The concentrations ranged from below detection limits to maximum values of 12.4 micrograms per liter of cis-1,2-dichloroethene, 1.14 micrograms per liter of trichloroethene, 2.65 micrograms per liter of tetrachloroethene, 1,070 micrograms per liter of methyl tert-butyl ether, 4.36 micrograms per liter of benzene, and 1.8 micrograms per liter of toluene. Vinyl chloride, ethylbenzene, p,m-xylene, and o-xylene were not detected in any of the samples collected during this investigation. Methyl tert-butyl ether was detected in 47 of the 115 ground-water samples. The highest methyl tert-butyl ether concentrations were found in the surficial aquifer from -4.6 to 6.4 feet mean sea level, however, methyl tert-butyl ether was detected as deep as -9.5 feet mean sea level. Increased methane concentrations and decreased dissolved oxygen concentrations were found in

  19. Molecular-beam sampling study of extinguishment of methane-air flames by dry chemicals

    NASA Technical Reports Server (NTRS)

    Knuth, E. L.; Ni, W.-F.; Seeger, C.

    1982-01-01

    The use of Al2O3, NaHCO3, KHCO3, NH4H2PO4 and KCl powders for the inhibition of a methane/oxygen diffusion flame is studied through measurement of composition and temperature profiles, using a molecular beam mass spectrometer sampling system. In order to obtain significant inhibition without extinguishing the flame, a powder feeding rate of 2 mg/liter of gas was used for KCl and Al2O3, and of 3 mg/liter of gas for the remaining powders. CH4, O2, N2, H2O and CO2 concentrations were measured by the mass spectrometer, while temperature was measured by the time-of-flight technique. For the powder feeding rates used, Al2O3 was the least and KCl and NH2H4PO2 the most effective in reducing temperature; in reaction-inhibition effectiveness, Al2O3 was again lowest while KCl was superior to all others. Because the KCl concentration was only 2/3 that of NH4H2PO4, it is recommended as the most effective temperature reducer and reaction inhibitor.

  20. Development of NO/NO{sub x}/NO{sub y} monitors for urban air sampling

    SciTech Connect

    Kelly, T.J.; Spicer, C.W.; Ward, G.F.

    1994-12-31

    The ideal methodology for NO, NO{sub x}, and NO{sub y} would have the following attributes: compatibility with existing monitoring network facilities and procedures; equipment cost in the range of current network NO{sub x} monitors; capability for specific monitoring of NO, NO{sub 2}, and NO{sub y}; detection limit of 0.1 ppb or lower. This report describes an evaluation of two approaches to meet these monitoring network needs. Both approaches make use of commercially available instruments for detection, with continuous pretreatment of the sample for selectivity. System A makes use of two commercial chemiluminescence instruments to monitor NO, NO{sub y}, and NO{sub 2}. System B utilizes the luminol chemiluminescence reaction to detect NO{sub 2}, and employs multiple catalysts to obtain measurements of NO{sub x} and NO{sub y}. This report describes these two approaches and evaluates them in terms of linearity, converter efficiency, interferences, and detection limits.

  1. Determination of trichloroanisole and trichlorophenol in wineries' ambient air by passive sampling and thermal desorption-gas chromatography coupled to tandem mass spectrometry.

    PubMed

    Camino-Sánchez, F J; Bermúdez-Peinado, R; Zafra-Gómez, A; Ruíz-García, J; Vílchez-Quero, J L

    2015-02-06

    The present paper describes the calibration of selected passive samplers used in the quantitation of trichlorophenol and trichloroanisole in wineries' ambient air, by calculating the corresponding sampling rates. The method is based on passive sampling with sorbent tubes and involves thermal desorption-gas chromatography-triple quadrupole mass spectrometry analysis. Three commercially available sorbents were tested using sampling cartridges with a radial design instead of axial ones. The best results were found for Tenax TA™. Sampling rates (R-values) for the selected sorbents were determined. Passive sampling was also used for accurately determining the amount of compounds present in the air. Adequate correlation coefficients between the mass of the target analytes and exposure time were obtained. The proposed validated method is a useful tool for the early detection of trichloroanisole and its precursor trichlorophenol in wineries' ambient air while avoiding contamination of wine or winery facilities.

  2. Optimization of automated gas sample collection and isotope ratio mass spectrometric analysis of delta(13)C of CO(2) in air.

    PubMed

    Zeeman, Matthias J; Werner, Roland A; Eugster, Werner; Siegwolf, Rolf T W; Wehrle, Günther; Mohn, Joachim; Buchmann, Nina

    2008-12-01

    The application of (13)C/(12)C in ecosystem-scale tracer models for CO(2) in air requires accurate measurements of the mixing ratios and stable isotope ratios of CO(2). To increase measurement reliability and data intercomparability, as well as to shorten analysis times, we have improved an existing field sampling setup with portable air sampling units and developed a laboratory setup for the analysis of the delta(13)C of CO(2) in air by isotope ratio mass spectrometry (IRMS). The changes consist of (a) optimization of sample and standard gas flow paths, (b) additional software configuration, and (c) automation of liquid nitrogen refilling for the cryogenic trap. We achieved a precision better than 0.1 per thousand and an accuracy of 0.11 +/- 0.04 per thousand for the measurement of delta(13)C of CO(2) in air and unattended operation of measurement sequences up to 12 h.

  3. Development and validation of a cleanup method for hydrocarbon containing samples for the analysis of semivolatile organic compounds

    SciTech Connect

    Hoppe, E.W.; Stromatt, R.W.; Campbell, J.A.; Steele, M.J.; Jones, J.E.

    1992-04-01

    Samples obtained from the Hanford single shell tanks (SSTs) are contaminated with normal paraffin hydrocarbon (NPH) as hydrostatic fluid from the sampling process or can be native to the tank waste. The contamination is usually high enough that a dilution of up to several orders of magnitude may be required before the sample can be analyzed by the conventional gas chromatography/mass spectrometry methodology. This can prevent detection and measurement of organic constituents that are present at lower concentration levels. To eliminate or minimize the problem, a sample cleanup method has been developed and validated and is presented in this document.

  4. Pilot study of sampling and analysis for polynuclear aromatic compounds in indoor air. Report for 1 February-30 September 1984

    SciTech Connect

    Chuang, J.C.; Mack, G.A.; Koetz, J.R.; Petersen, B.A.

    1986-12-01

    The report presents the results of a nine-home indoor-air study that the authors performed in Columbus, Ohio in the winter of 1984. The main objective of the study was the field evaluation of sampling and analysis methodology. However, several additional results of the study are interesting and useful, including the finding of polynuclear aromatic hydrocarbons (PAH) at levels from 0.000 to 143 ng/cu m in residences, strong correlations of these levels with smoking by occupants, little influence of fireplace use on the PAH levels, the identification of quinoline as a potential marker for cigarette smoking, and measurement of 2- and 3-nitrofluoranthene, which are potent mutagens, at significant levels from 0.000 to 0.185 ng/cu m, also correlated with smoking.

  5. Personal air sampling and biological monitoring of occupational exposure to the soil fumigant cis-1,3-dichloropropene

    PubMed Central

    Brouwer, E; Verplanke, A; Boogaard, P; Bloemen, L; Van Sittert, N J; Christian, F; Stokkentreeff, M; Dijksterhuis, A; Mulder, A; De Wolff, F A

    2000-01-01

    OBJECTIVES—To assess exposure of commercial application workers to the nematocide cis-1,3-dichloropropene (cis-DCP).
METHODS—The study was conducted during the annual application season, August to 15 November, in the starch potato growing region in The Netherlands. 14 Application workers collected end of shift urine samples on each fumigation day (n=119). The mercapturic acid metabolite N-acetyl-S-(cis-3-chloro-2-propenyl)-L-cysteine (cis-DCP-MA) in urine was used for biological monitoring of the cis-DCP uptake. Inhalatory exposure was assessed by personal air sampling during a representative sample (n=37) of the fumigation days. Extensive information was collected on factors of possible relevance to the exposure and the application workers were observed for compliance with the statutory directions for use. The inhalatory exposure during all fumigation days was estimated from the relation between the personal air sampling data and the biological monitoring data. Exposure levels were correlated with the general work practice. The fumigation equipment and procedures were in accordance with the statutory directions of use, with the exception of the antidrip systems. Two antidrip systems were used: antidrip nozzles or a compressed air system.
RESULTS—The geometric mean exposure of the application workers was 2.7 mg/m3 (8 hour time weighted average); range 0.1-9.5 mg/m3. On 25 days (21%) the exposure exceeded the Dutch occupational exposure limit (OEL) of 5 mg/m3. This could mainly be explained by prolonged working days of more than 8 hours. The general work practice of the application workers was rated by the observers as good or poor. No difference in exposure to cis-DCP was found in the use of none, one, or two antidrip systems. Malfunctioning of the antidrip systems and lack of experience with the compressed air system were identified as possible causes for the lack of effectiveness of these antidrip systems. The use of personal protection was not

  6. Saturation sampling for spatial variation in multiple air pollutants across an inversion-prone metropolitan area of complex terrain

    PubMed Central

    2014-01-01

    Background Characterizing intra-urban variation in air quality is important for epidemiological investigation of health outcomes and disparities. To date, however, few studies have been designed to capture spatial variation during select hours of the day, or to examine the roles of meteorology and complex terrain in shaping intra-urban exposure gradients. Methods We designed a spatial saturation monitoring study to target local air pollution sources, and to understand the role of topography and temperature inversions on fine-scale pollution variation by systematically allocating sampling locations across gradients in key local emissions sources (vehicle traffic, industrial facilities) and topography (elevation) in the Pittsburgh area. Street-level integrated samples of fine particulate matter (PM2.5), black carbon (BC), nitrogen dioxide (NO2), sulfur dioxide (SO2), and ozone (O3) were collected during morning rush and probable inversion hours (6-11 AM), during summer and winter. We hypothesized that pollution concentrations would be: 1) higher under inversion conditions, 2) exacerbated in lower-elevation areas, and 3) vary by season. Results During July - August 2011 and January - March 2012, we observed wide spatial and seasonal variability in pollution concentrations, exceeding the range measured at regulatory monitors. We identified elevated concentrations of multiple pollutants at lower-elevation sites, and a positive association between inversion frequency and NO2 concentration. We examined temporal adjustment methods for deriving seasonal concentration estimates, and found that the appropriate reference temporal trend differs between pollutants. Conclusions Our time-stratified spatial saturation approach found some evidence for modification of inversion-concentration relationships by topography, and provided useful insights for refining and interpreting GIS-based pollution source indicators for Land Use Regression modeling. PMID:24735818

  7. Air,

    DTIC Science & Technology

    each sampling point to account for the general bacterial inoculation and two dishes with chocolate agar for detecting streptococcus viridans. The...number of colonies, which grew on the two dishes, is computed. The dishes with chocolate agar are held in the thermostatically controlled chamber for two days, after which any suspicious colonies are computed.

  8. Asbestos-containing materials in school buildings: Bulk-sample analysis quality-assurance program. Bulk sample rounds 16, 17 and 18

    SciTech Connect

    Starner, K.K.; Perkins, R.L.; Harvey, B.W.; Westbrook, S.H.

    1990-02-01

    The report presents the performance results of laboratories participating in the sixteenth, seventeenth and eighteenth rounds of the Bulk Sample Analysis Quality Assurance Program sponsored by the United States Environmental Protection Agency, (EPA). Round 16 of the program operated along the guidelines established in previous rounds and was a voluntary quality assurance program. The Asbestos Hazard Emergency Response Act of 1986 (AHERA), directed the National Institute of Standards and Technology (NIST) to establish and maintain a laboratory accreditation program for bulk sample analysis of asbestos. The program began in October 1988 by evaluating enrolled polariscope laboratories in the interim prior to the initiation of the National Voluntary Laboratory Accreditation Program (NVLAP) for bulk asbestos laboratories, sponsored by NIST.

  9. Single vessel air injection estimates of xylem resistance to cavitation are affected by vessel network characteristics and sample length.

    PubMed

    Venturas, Martin D; Rodriguez-Zaccaro, F Daniela; Percolla, Marta I; Crous, Casparus J; Jacobsen, Anna L; Pratt, R Brandon

    2016-10-01

    Xylem resistance to cavitation is an important trait that is related to the ecology and survival of plant species. Vessel network characteristics, such as vessel length and connectivity, could affect the spread of emboli from gas-filled vessels to functional ones, triggering their cavitation. We hypothesized that the cavitation resistance of xylem vessels is randomly distributed throughout the vessel network. We predicted that single vessel air injection (SVAI) vulnerability curves (VCs) would thus be affected by sample length. Longer stem samples were predicted to appear more resistant than shorter samples due to the sampled path including greater numbers of vessels. We evaluated the vessel network characteristics of grapevine (Vitis vinifera L.), English oak (Quercus robur L.) and black cottonwood (Populus trichocarpa Torr. & A. Gray), and constructed SVAI VCs for 5- and 20-cm-long segments. We also constructed VCs with a standard centrifuge method and used computer modelling to estimate the curve shift expected for pathways composed of different numbers of vessels. For all three species, the SVAI VCs for 5 cm segments rose exponentially and were more vulnerable than the 20 cm segments. The 5 cm curve shapes were exponential and were consistent with centrifuge VCs. Modelling data supported the observed SVAI VC shifts, which were related to path length and vessel network characteristics. These results suggest that exponential VCs represent the most realistic curve shape for individual vessel resistance distributions for these species. At the network level, the presence of some vessels with a higher resistance to cavitation may help avoid emboli spread during tissue dehydration.

  10. CTEPP STANDARD OPERATING PROCEDURE FOR EXTRACTING AND PREPARING AIR SAMPLES FOR ANALYSIS OF NEUTRAL PERSISTENT ORGANIC POLLUTANTS (SOP-5.12)

    EPA Science Inventory

    The method is for extracting an indoor and outdoor air sample consisting of a quartz fiber filter and an XAD-2 cartridge for analysis of neutral persistent organic pollutants. It covers the extraction and concentration of samples that are to be analyzed by gas chromatography/mass...

  11. STS 127 Return Samples: Assessment of Air Quality aboard the Shuttle (STS-127) and International Space Station (2J/A)

    NASA Technical Reports Server (NTRS)

    James, John T.

    2010-01-01

    The toxicological assessments of 2 grab sample canisters (GSCs) from the Shuttle are reported. The toxicological assessment of 9 GSCs and 6 pairs of formaldehyde badges from the ISS is also reported. Other than a problem with traces of acrolein in the samples, the air quality was acceptable for respiration.

  12. Determination of some traces metal levels in cheese samples packaged in plastic and tin containers by ICP-OES after dry, wet and microwave digestion.

    PubMed

    Bakircioglu, Dilek; Kurtulus, Yasemin Bakircioglu; Ucar, Gokhan

    2011-01-01

    The concentrations of Cd, Co, Cr, Cu, Mn, Ni, Pb, Se and Zn in cheese samples packaged in plastic and tin containers were analyzed using inductively coupled plasma-optical emission spectrometry after microwave, wet and dry digestion processes. In order to evaluate the best digestion method, the relationships between the concentrations of trace metals in cheese samples after microwave digestion was compared by wet and dry ashings. Microwave digestion was found fast, reliable, simple, and excellent procedure in comparison with dry and wet ashing methods. The accuracy of the digestion procedures was determined by using standard reference material (GBW 07605-Tea). The order of levels of the elements in the white cheese samples packaged in tin containers was determined to be Cdsamples in plastic containers Cdsamples packaged in tin and plastic containers, indicating that cheese types and packaging materials play a key role in the content of trace metal.

  13. (Collection of North Pacific Ocean surface seawater samples from a container ship): Foreign trip report, January 24--March 4, 1989

    SciTech Connect

    Goddard, J.G.

    1989-03-16

    This trip was a continuation of the sampling program undertaken during 1984--1985 to study the seasonal and regional variability of CO/sub 2/ chemistry in high-latitude deep water formation areas of the North Pacific. The work is conducted by Columbia University (Dr. Taro Takahashi, Principal Investigator) for the Department of Energy's Energy Systems Program managed by Oak Ridge National Laboratory. Aboard the President Eisenhower, we collected surface seawater samples at forty-two stations along the route from Oakland, California, to Keelung, Taiwan, via Guam. On the return trip, samples were collected from thirty-nine stations during transit from Kaohsiung, Taiwan, to Los Angeles, California.

  14. Vapor-phase and particulate-associated pesticides and PCB concentrations in eastern North Dakota air samples

    SciTech Connect

    Hawthorne, S.B.; Miller, D.J.; Louie, P.K.K.

    1996-05-01

    Vapor-phase and suspended particulate (<50 {mu}m) samples were collected on polyurethane foam (PUF) and quartz fiber filters in rural North Dakota to determine the air concentrations of pesticides in an area where agriculture is a primary source of semivolatile pollutants. Samples were collected at two sites from 1992 to 1994 that were at least 0.4 km from the nearest farmed fields and known application of pesticides, and analyzed for 22 different organochlorine, triazine, and acid herbicide pesticides. Fourteen pesticides were found above the detection limits (typically <1 pg/m{sup 3}). Concentrations of polychlorinated biphenyl (PCB) congeners were much lower (<50 pg/m{sup 3} in all cases) than many of the pesticides. These results demonstrate that pesticides are among the most prevalent chlorinated semivolatile pollutants present in rural North Dakota, that significant transport of pesticides occurs both in the vapor-phase and on suspended particulate matter, and that blown soil may be a significant mechanism for introducing pesticides into surface and ground waters. 32 refs., 2 figs., 4 tabs.

  15. Prevalence rates of respiratory symptoms in Italian general population samples exposed to different levels of air pollution

    SciTech Connect

    Viegi, G. Univ. of Arizona, Tucson ); Paoletti, P.; Carrozzi, L.; Vellutini, M.; Diviggiano, E.; Pistelli, G.; Giutini, G. ); Di Pede, C. Occupational Medicine Service, Toscana ); Lebowitz, M.D. )

    1991-08-01

    The authors surveyed two general population samples aged 8 to 64 living in the unpolluted, rural area of the Po Delta (northern Italy) and in the urban area of Pisa (central Italy). Each subject filled out a standardized interviewer-administered questionnaire. The Pisa sample was divided into three groups according to their residence in the urban-suburban areas and to outdoor air pollution exposure (automobile exhaust only or industrial fumes as well). Significantly higher prevalence rates of all the respiratory symptoms and diseases were found in Pisa compared with the Po Delta. Current smoking was more frequent in the rural area, but the urban smokers had a higher lifetime cigarette consumption. Childhood respiratory trouble and recurrent respiratory illnesses were evenly distributed. Exposure to parental smoking in childhood and lower educational level were more frequent in Po Delta, whereas familial history of respiratory/allergic disorders and work and indoor exposures were more often reported in the city. Multiple logistic regression models estimating independently the role of the various risk factors showed significant odds ratios associated with residence in Pisa for all the symptoms but chronic phlegm. The conclusion, these preliminary analyses indicate an urban factor related to the rates of respiratory symptoms and diseases in Italy in the 1980s.

  16. Volatile N-nitrosamines in Environment Tobacco Smoke: Sampling,Analysis, Smission Factors, and Indoor Air Exposures

    SciTech Connect

    Mahanama, K.R.R.; Daisey, J.M.

    1995-05-01

    A more convenient sampling and analysis method for the volatile N-nitrosamines (VNA) in ETS, using commercially available TherrnosorbIN cartridges, was developed and validated. Using the method, emission factors for the two major VNA in environmental tobacco smoke (ETS) were determined in a room-sized environmental chamber for six commercial cigarette brands, which together accounted for 62.5% of the total market in California in 1990. The average emission factors were 565 {+-} 115 and 104 {+-} 20 ng per cigarette for N-nitrosodimethylamine and N-nitrosopyrrolidine, respectively. The emission factors were used to estimate VNA exposures from ETS in a typical office building and an average residence. Indoor concentrations of N,N dimethylnitrosamine from ETS for these scenarios were less than 10% of the reported median outdoor concentration. This median outdoor concentration, however, includes many measurements made in source-dominated areas and may be considerably higher than one based on more representative sampling of outdoor air.

  17. Direct measurements of sample heating by a laser-induced air plasma in pre-ablation spark dual-pulse laser-induced breakdown spectroscopy (LIBS).

    PubMed

    Register, Janna; Scaffidi, Jonathan; Angel, S Michael

    2012-08-01

    Direct measurements of temperature changes were made using small thermocouples (TC), placed near a laser-induced air plasma. Temperature changes up to ~500 °C were observed. From the measured temperature changes, estimates were made of the amount of heat absorbed per unit area. This allowed calculations to be made of the surface temperature, as a function of time, of a sample heated by the air plasma that is generated during orthogonal pre-ablation spark dual-pulse (DP) LIBS measurements. In separate experiments, single-pulse (SP) LIBS emission and sample ablation rate measurements were performed on nickel at sample temperatures ranging from room temperature to the maximum surface temperature that was calculated using the TC measurement results (500 °C). A small, but real sample temperature-dependent increase in both SP LIBS emission and the rate of sample ablation was found for nickel samples heated up to 500 °C. Comparison of DP LIBS emission enhancement values for bulk nickel samples at room temperature versus the enhanced SP LIBS emission and sample ablation rates observed as a function of increasing sample temperature suggests that sample heating by the laser-induced air plasma plays only a minor role in DP LIBS emission enhancement.

  18. [The gas chromatographic determination of sulfur- and oxygen-containing organic compounds released into the air of cellulose sulfate works].

    PubMed

    Taranenko, N A; Dorogova, V B

    1992-01-01

    The article presents data on the design of sensitive, selective, useful in group analysis method to detect dimethylsulphide, dimethyldisulphide, acetic, propionic, butyric and valeric acids, methyl alcohol and phenol by means of gas chromatography in the air of cellulose sulphate production working zone. The methods were tested in examining the work conditions in Bratsk found-lavage shops.

  19. Development of an international standard for the determination of metals and metalloids in workplace air using ICP-AES: evaluation of sample dissolution procedures through an interlaboratory trial.

    PubMed

    Butler, O T; Howe, A M

    1999-02-01

    Inductively coupled plasma atomic emission spectrometry (ICP-AES) is rapidly overtaking atomic absorption spectrometry (AAS) as the method of choice for the determination of toxic metals in workplace air. However, the few ICP-AES methods that have been published are not well characterised in terms of the effectiveness of the sample dissolution procedures described and their validation status. The International Standards Organization (ISO) is currently engaged in developing ISO 15202, which will describe a generic method for the determination of metals and metalloids in airborne particulate matter by ICP-AES. One part of the proposed standard deals with dissolution procedures. The ISO work has been supported by a project carried out in the authors' laboratory to identify, develop and validate sample dissolution procedures for inclusion in the proposed standard. This paper describes an interlaboratory comparison carried out to assess the performance of selected procedures using samples of airborne particulate matter collected on filters with a multiport sampler. Five dissolution procedures were tested. These included an ultrasonic agitation procedure, two hot-plate procedures (based upon NIOSH 7300 and OSHA ID 125G) and two microwave-assisted procedures (based upon EPA 3052). It was shown that the dissolution procedures selected for use in the trial and used internally at HSL generally gave equivalent performance. As expected, a wider spread of results was obtained by participants in the trial. More specifically, there exists some reservation regarding the ability of the ultrasonic and hot-plate procedures to attack fully on a consistent basis some resistant materials, e.g., chromium containing particulate matter. Above all, the trial demonstrated the usefulness of microwave-assisted dissolution procedures in a modern laboratory.

  20. Effect of exposure conditions on the long-term dielectric properties of mortar samples containing ASR gel

    NASA Astrophysics Data System (ADS)

    Hashemi, A.; Donnell, K. M.; Zoughi, R.; Rashidi, M.; Kurtis, K. E.

    2017-02-01

    Alkali-silica reaction (ASR) is a chemical reaction between alkalis present in portland cement and amorphous or otherwise disordered siliceous minerals in particular aggregates. Through this reaction, reactive silica binds with hydroxyl and alkali ions and forms a gel, known as ASR gel. Recently, microwave materials characterization techniques have shown great potential for detecting ASR in mortar. However, the comprehensive understanding of variables that affect the extent of ASR in mortar and their interaction with microwave signals, in particular the effect of environmental exposure conditions requires more investigations. Therefore, parameters related to these conditions must be considered when using microwave techniques for ASR detection and evaluation. In this paper, the effect of exposure conditions on ASR gel formation and microwave dielectric properties of mortar samples is investigated. To this end, extended measurements of the complex dielectric constants of three different sets of mortar samples are presented at S-band (2.6 - 3.95 GHz). The samples were cast with potentially reactive ASR-aggregates and subjected to different environmental conditions. The results show slightly different permittivities for the differently stored samples, potentially indicating different amount of ASR gel. This observation was corroborated through UV fluorescence microscopy, where different amounts of ASR gel were observed in the samples. Moreover, the results indicate that ASR gel evolution may be better tracked through loss factor measurements, while pre-existing-gel may be better detected through permittivity measurements.