Science.gov

Sample records for air sample analysis

  1. 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.

  2. 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.

  3. 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...

  4. 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...

  5. 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.

  6. 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.

  7. 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

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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).

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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).

  8. 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.

  9. 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

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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...

  15. 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

  16. 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

  17. 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

  18. 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.

  19. 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

  20. 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.

  1. Portable XRF analysis of occupational air filter samples from different workplaces using different samplers: final results, summary and conclusions.

    PubMed

    Harper, Martin; Pacolay, Bruce; Hintz, Patrick; Bartley, David L; Slaven, James E; Andrew, Michael E

    2007-11-01

    This paper concludes a five-year program on research into the use of a portable X-ray fluorescence (XRF) analyzer for analyzing lead in air sampling filters from different industrial environments, including mining, manufacturing and recycling. The results from four of these environments have already been reported. The results from two additional metal processes are presented here. At both of these sites, lead was a minor component of the total airborne metals and interferences from other elements were minimal. Nevertheless, only results from the three sites where lead was the most abundant metal were used in the overall calculation of method accuracy. The XRF analyzer was used to interrogate the filters, which were then subjected to acid digestion and analysis by inductively-coupled plasma optical-emission spectroscopy (ICP-OES). The filter samples were collected using different filter-holders or "samplers" where the size (diameter), depth and homogeneity of aerosol deposit varied from sampler to sampler. The aerosol collection efficiencies of the samplers were expected to differ, especially for larger particles. The distribution of particles once having entered the sampler was also expected to differ between samplers. Samplers were paired to allow the between-sampler variability to be addressed, and, in some cases, internal sampler wall deposits were evaluated and compared to the filter catch. It was found, rather surprisingly, that analysis of the filter deposits (by ICP-OES) of all the samplers gave equivalent results. It was also found that deposits on some of the sampler walls, which in some protocols are considered part of the sample, could be significant in comparison to the filter deposit. If it is concluded that wall-deposits should be analyzed, then XRF analysis of the filter can only give a minimum estimate of the concentration. Techniques for the statistical analysis of field data were also developed as part of this program and have been reported

  2. 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.

  3. 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

  4. 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.

  5. Capillary thermal desorption unit for near real-time analysis of VOCs at sub-trace levels. Application to the analysis of environmental air contamination and breath samples.

    PubMed

    Alonso, Mónica; Castellanos, Mar; Martín, José; Sanchez, Juan M

    2009-05-15

    A capillary microtrap thermal desorption module is developed for near real-time analysis of volatile organic compounds (VOCs) at sub-ppbv levels in air samples. The device allows the direct injection of the thermally desorbed VOCs into a chromatographic column. It does not use a second cryotrap to focalize the adsorbed compounds before entering the separation column so reducing the formation of artifacts. The connection of the microtrap to a GC-MS allows the quantitative determination of VOCs in less than 40 min with detection limits of between 5 and 10 pptv (25 degrees C and 760 mm Hg), which correspond to 19-43 ng m(-3), using sampling volumes of 775 cm(3). The microtrap is applied to the analysis of environmental air contamination in different laboratories of our faculty. The results obtained indicate that most volatile compounds are easily diffused through the air and that they also may contaminate the surrounding areas when the habitual safety precautions (e.g., working under fume hoods) are used during the manipulation of solvents. The application of the microtrap to the analysis of VOCs in breath samples suggest that 2,5-dimethylfuran may be a strong indicator of a person's smoking status.

  6. 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...

  7. 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.

  8. 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.

  9. 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.

  10. Size-fractionated sampling and chemical analysis by total-reflection X-ray fluorescence spectrometry of PMx in ambient air and emissions

    NASA Astrophysics Data System (ADS)

    John, A. C.; Kuhlbusch, T. A. J.; Fissan, H.; Schmidt, K.-G.

    2001-11-01

    PM 10 and PM 2.5 (PMx) have been recently introduced as new air quality standards in the EU (Council Directive 1999/30/EC) for particulate matter. Different estimates and measurements showed that the limit values for PM 10 will be exceeded at different locations in Europe, and thus measures will have to be taken to reduce PMx mass concentrations. Source apportionment has to be carried out, demanding comparable methods for ambient air and emission sampling and chemical analysis. Therefore, a special ambient-air sampler and a specially designed emission sampler have been developed. Total-reflection X-ray fluorescence analysis (TXRF) was used for multi-element analyses as a fast method with low detection limits. For ambient air measurements, a sampling unit was built, impacting particle size classes 10-2.5 μm and 2.5-1.0 μm directly onto TXRF sample carriers. An electrostatic precipitator (ESP) was used as back-up filter to also collect particles <1 μm directly onto the TXRF sample carriers. Air quality is affected by natural and anthropogenic sources, and the emissions of particles <10 μm and <2.5 μm, respectively, have to be determined to quantify their contributions to the so-called coarse (10-2.5 μm) and fine (<2.5 μm) particle modes in ambient air. For this, an in-stack particle sampling system was developed, according to the new ambient air quality standards and in view of subsequent analysis by TXRF. These newly developed samplers, in combination with TXRF analyses, were employed in field campaigns to prove the feasibility and capabilities of the approach. Ambient air data show the quantification of a wide spectrum of elements. From those concentrations, PMx ratios were calculated as an indicator for different sources of elements. Results useful for source apportionment are also the elemental day/night ratios calculated to determine local contributions to PMx mass concentrations. With regard to the emission measurements, results of mass and elemental

  11. Integrated sampling and analysis unit for the determination of sexual pheromones in environmental air using fabric phase sorptive extraction and headspace-gas chromatography-mass spectrometry.

    PubMed

    Alcudia-León, M Carmen; Lucena, Rafael; Cárdenas, Soledad; Valcárcel, Miguel; Kabir, Abuzar; Furton, Kenneth G

    2017-03-10

    This article presents a novel unit that integrates for the first time air sampling and preconcentration based on the use of fabric phase sorptive extraction principles. The determination of Tuta absoluta sexual pheromone traces in environmental air has been selected as analytical problem. For this aim, a novel laboratory-built unit made up of commercial brass elements as holder of the sol-gel coated fabric extracting phase has been designed and optimized. The performance of the integrated unit was evaluated analyzing environmental air sampled in tomato crops. The unit can work under sampling and analysis mode which eliminates any need for sorptive phase manipulation prior to instrumental analysis. In the sampling mode, the unit can be connected to a sampling pump to pass the air through the sorptive phase at a controlled flow-rate. In the analysis mode, it is placed in the gas chromatograph autosampler without any instrumental modification. It also diminishes the risk of cross contamination between sampling and analysis. The performance of the new unit has been evaluated using the main components of the sexual pheromone of Tuta absoluta [(3E,8Z,11Z)-tetradecatrien-1-yl acetate and (3E,8Z)-tetradecadien-1-yl acetate] as model analytes. The limits of detection for both compounds resulted to be 1.6μg and 0.8μg, respectively, while the precision (expressed as relative standard deviation) was better than 3.7%. Finally, the unit has been deployed in the field to analyze a number of real life samples, some of them were found positive.

  12. 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.

  13. 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...

  14. 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.

  15. Quantification of VX vapor in ambient air by liquid chromatography isotope dilution tandem mass spectrometric analysis of glass bead filled sampling tubes.

    PubMed

    Evans, Ronald A; Smith, Wendy L; Nguyen, Nam-Phuong; Crouse, Kathy L; Crouse, Charles L; Norman, Steven D; Jakubowski, E Michael

    2011-02-15

    An analysis method has been developed for determining low parts-per-quadrillion by volume (ppqv) concentrations of nerve agent VX vapor actively sampled from ambient air. The method utilizes glass bead filled depot area air monitoring system (DAAMS) sampling tubes with isopropyl alcohol extraction and isotope dilution using liquid chromatography coupled with a triple-quadrupole mass spectrometer (LC/MS/MS) with positive ion electrospray ionization for quantitation. The dynamic range was from one-tenth of the worker population limit (WPL) to the short-term exposure limit (STEL) for a 24 L air sample taken over a 1 h period. The precision and accuracy of the method were evaluated using liquid-spiked tubes, and the collection characteristics of the DAAMS tubes were assessed by collecting trace level vapor generated in a 1000 L continuous flow chamber. The method described here has significant improvements over currently employed thermal desorption techniques that utilize a silver fluoride pad during sampling to convert VX to a higher volatility G-analogue for gas chromatographic analysis. The benefits of this method are the ability to directly analyze VX with improved selectivity and sensitivity, the injection of a fraction of the extract, quantitation using an isotopically labeled internal standard, and a short instrument cycle time.

  16. Minimisation of artefact formation of dimethyl disulphide during sampling and analysis of methanethiol in air using solid sorbent materials.

    PubMed

    Andersen, Kristin Barkve; Hansen, Michael Jørgen; Feilberg, Anders

    2012-07-06

    Methanethiol (MT) is a potent odorant that can be difficult to measure due to its high volatility and reactivity; it easily reacts to form dimethyl disulphide (DMDS) during sampling and/or analysis. This paper focuses on finding an optimal method for sampling and measuring MT with minimum artefact formation using sorbent materials and a thermal desorption-gas chromatography-mass spectrometry method (TD-GC-MS). Experiments were conducted to identify suitable sorbent materials and tubes for analysis. Breakthrough, desorption rate, the effects of storage and desorption temperatures were investigated and different drying methods were established with respect to quantitative sampling and formation of DMDS. Proton-transfer-reaction mass spectrometry (PTR-MS) was used in the development of the method and was an especially useful tool for determination of breakthrough. The results show that glass tubes packed with silica gel for pre-concentration of MT before analysis with TD-GC-MS give the best results. In addition, a combination of Tenax TA and carbonised molecular sieve or Tenax TA cooled to ≤0°C gives acceptable results. 80°C was found to be the optimal desorption temperature. For all the sampling methods tested, storage conditions were observed to be very critical for transformation of MT. Room temperature storage should be limited to few minutes and, in general, tubes should be kept at 0°C or lower during storage.

  17. Development of a method for the determination of naphthalene and phenanthrene in workplace air using diffusive sampling and thermal desorption GC-MS analysis.

    PubMed

    Lindahl, Roger; Claesson, Anna-Sara; Khan, Muhammad Akhtar; Levin, Jan-Olof

    2011-07-01

    Diffusive sampling methods have been validated for the determination of naphthalene and phenanthrene in workplace air. The diffusive sampler tested was the Perkin Elmer ATD tube, and the analysis was performed with thermal desorption, gas chromatography, and mass spectrometric detection. The sampling methods were validated in controlled test atmospheres, mainly according to the protocol proposed in the European standard EN 838. For the determination of naphthalene, the diffusive sampling rate was 0.41 ml min(-1) with a coefficient of variation (CV) of 19%. The mean sampling rate for phenanthrene was 0.49 ml min(-1) with a CV of 21%. Field tests confirmed the naphthalene results but could not be used to confirm the phenanthrene results. The method is not recommended for phenanthrene sampling unless the method has been tested in the specific environment and the results confirm the laboratory tests.

  18. 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.

  19. 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.

  20. Application of a high surface area solid-phase microextraction air sampling device: collection and analysis of chemical warfare agent surrogate and degradation compounds.

    PubMed

    Stevens, Michael E; Tipple, Christopher A; Smith, Philip A; Cho, David S; Mustacich, Robert V; Eckenrode, Brian A

    2013-09-17

    This work examines a recently improved, dynamic air sampling technique, high surface area solid-phase microextraction (HSA-SPME), developed for time-critical, high-volume sampling and analysis scenarios. The previously reported HSA-SPME sampling device, which provides 10-fold greater surface area compared to commercially available SPME fibers, allowed for an increased analyte uptake per unit time relative to exhaustive sampling through a standard sorbent tube. This sampling device has been improved with the addition of a type-K thermocouple and a custom heater control circuit for direct heating, providing precise (relative standard deviation ∼1%) temperature control of the desorption process for trapped analytes. Power requirements for the HSA-SPME desorption process were 30-fold lower than those for conventional sorbent-bed-based desorption devices, an important quality for a device that could be used for field analysis. Comparisons of the HSA-SPME device when using fixed sampling times for the chemical warfare agent (CWA) surrogate compound, diisopropyl methylphosphonate (DIMP), demonstrated that the HSA-SPME device yielded a greater chromatographic response (up to 50%) relative to a sorbent-bed method. Another HSA-SPME air sampling approach, in which two devices are joined in tandem, was also evaluated for very rapid, low-level, and representative analysis when using discrete sampling times for the compounds of interest. The results indicated that subparts per billion by volume concentration levels of DIMP were detectable with short sampling times (∼15 s). Finally, the tandem HSA-SPME device was employed for the headspace sampling of a CWA degradation compound, 2-(diisopropylaminoethyl) ethyl sulfide, present on cloth material, which demonstrated the capability to detect trace amounts of a CWA degradation product that is estimated to be less volatile than sarin. The rapid and highly sensitive detection features of this device may be beneficial in decision

  1. A novel needle trap device with single wall carbon nanotubes sol-gel sorbent packed for sampling and analysis of volatile organohalogen compounds in air.

    PubMed

    Heidari, Mahmoud; Bahrami, Abdolrahman; Ghiasvand, Ali Reza; Shahna, Farshid Ghorbani; Soltanian, Ali Reza

    2012-11-15

    This paper describes a new approach that combines needle trap devices (NTDs) with a newly synthesized silanated nano material as sorbent for sampling and analysis of HVOCs in air. The sol-gel technique was used for preparation of the single wall carbon nanotube (SWCNT)/silica composite as sorbent, packed inside a 21-gauge NTD. Application of this method as an exhaustive sampler device was investigated under different laboratory conditions in this study. Predetermined concentrations of each analyte were prepared in a home-made standard chamber, and the effects of experimental parameters, such as temperature, humidity, sampling air flow rate, breakthrough volume and storage time on NTD, and the sorbent performance were investigated. The proposed NTD was used in two different modes and two different injection methods, and an NTD with a side hole, a narrow neck glass liner and syringe pump assisted injection of carrier gas were applied. The NTD packed with SWCNTs/silica composite was compared to the NTD packed with PDMS and also SPME with CAR/PDMS. For four compounds, LOD was 0.001-0.01 ng mL(-1), LOQ was 0.007-0.03 ng mL(-1), and the relative standard division for repeatability of method was 2.5-6.7%. The results show that the incorporation of NTD and SWCNTs/silica composite is a reliable and effective approach for the sampling and analysis of HVOCs in air. Coupling this system to GC-MS make it more sensitive and powerful technique.

  2. 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...

  3. [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).

  4. Evaluation of Loring Air Force Base, Maine, in Preparation for a Public Health Assessment - Data Gap Sampling and Analysis Plan

    DTIC Science & Technology

    1994-06-01

    POVM) or active charcoal tubes can be used as the sampling media. All samples should be taken at fixed locations approximately four to five feet...Public Health Assessm ent Process .......................................................... 1 ALIO EM H Base Scoping Visit Activities ...11 Receiver Site (SS-04) ................................................................... 11 IRP Remediation Activities (SD-32

  5. 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)

  6. 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.

  7. 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

  8. 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

  9. 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

  10. 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...

  11. 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...

  12. 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...

  13. 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...

  14. 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...

  15. SAMPLING AND ANALYSIS PROTOCOLS

    SciTech Connect

    Jannik, T; P Fledderman, P

    2007-02-09

    Radiological sampling and analyses are performed to collect data for a variety of specific reasons covering a wide range of projects. These activities include: Effluent monitoring; Environmental surveillance; Emergency response; Routine ambient monitoring; Background assessments; Nuclear license termination; Remediation; Deactivation and decommissioning (D&D); and Waste management. In this chapter, effluent monitoring and environmental surveillance programs at nuclear operating facilities and radiological sampling and analysis plans for remediation and D&D activities will be discussed.

  16. 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.

  17. Air Force JP-8 Fuel Distribution System: A Statistical Analysis to Determine Where and When to Sample

    DTIC Science & Technology

    2005-03-01

    1620 1622 1624 DF 10.0489 1744.3385 1754.3874 -LogLike 0.0057 RSquare (U) Likelihood Ratio Pearson Test 20.098 23.765 ChiSquare ... ChiSquare 0.0264 0.0278 Prob>ChiSq Tests Contingency Analysis of Location By Pass Rate 91 Misawa AB Results Lo ca tio n 0.00 0.25 0.50 0.75...0.577 0.308 ChiSquare 0.7494 0.8571 Prob>ChiSq Warning: 20% of cells have expected count less than 5, ChiSquare suspect Tests Contingency

  18. AIR Model Preflight Analysis

    NASA Technical Reports Server (NTRS)

    Tai, H.; Wilson, J. W.; Maiden, D. L.

    2003-01-01

    The atmospheric ionizing radiation (AIR) ER-2 preflight analysis, one of the first attempts to obtain a relatively complete measurement set of the high-altitude radiation level environment, is described in this paper. The primary thrust is to characterize the atmospheric radiation and to define dose levels at high-altitude flight. A secondary thrust is to develop and validate dosimetric techniques and monitoring devices for protecting aircrews. With a few chosen routes, we can measure the experimental results and validate the AIR model predictions. Eventually, as more measurements are made, we gain more understanding about the hazardous radiation environment and acquire more confidence in the prediction models.

  19. 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.

  20. Lunar sample analysis

    NASA Technical Reports Server (NTRS)

    Housley, R. M.

    1986-01-01

    A wide variety of lunar sample and meteorite studies were performed. Abstracts of the most recent reports are also attached. Experimental techniques employed have included scanning electron microscopy, transmission electron microscopy, Mossbauer spectroscopy, atomic absorption analysis and a variety of simulation studies.

  1. [Environmental investigation of ground water contamination at Wright-Patterson Air Force Base, Ohio]. Volume 3, Sampling and analysis plan (SAP): Phase 1, Task 4, Field Investigation: Draft

    SciTech Connect

    Not Available

    1991-10-01

    In April 1990, Wright-Patterson Air Force Base (WPAFB), initiated an investigation to evaluate a potential Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) removal action to prevent, to the extent practicable, the offsite migration of contaminated ground water from WPAFB. WPAFB retained the services of the Environmental Management Operations (EMO) and its principle subcontractor, International Technology Corporation (IT) to complete Phase 1 of the environmental investigation of ground-water contamination at WPAFB. Phase 1 of the investigation involves the short-term evaluation and potential design for a program to remove ground-water contamination that appears to be migrating across the western boundary of Area C, and across the northern boundary of Area B along Springfield Pike. Primarily, Task 4 of Phase 1 focuses on collection of information at the Area C and Springfield Pike boundaries of WPAFB. This Sampling and Analysis Plan (SAP) has been prepared to assist in completion of the Task 4 field investigation and is comprised of the Quality Assurance Project Plan (QAPP) and the Field Sampling Plan (FSP).

  2. Germanium-76 Sample Analysis

    SciTech Connect

    Kouzes, Richard T.; Engelhard, Mark H.; Zhu, Zihua

    2011-04-01

    The MAJORANA DEMONSTRATOR is a large array of ultra-low background high-purity germanium detectors, enriched in 76Ge, designed to search for zero-neutrino double-beta decay (0νββ). The DEMONSTRATOR will utilize 76Ge from Russia, and the first one gram sample was received from the supplier for analysis on April 24, 2011. The Environmental Molecular Sciences facility, a DOE user facility at PNNL, was used to make the required isotopic and chemical purity measurements that are essential to the quality assurance for the MAJORANA DEMONSTRATOR. The results of this first analysis are reported here.

  3. Simultaneous sampling and analysis of indoor air infested with Cimex lectularius L. (Hemiptera: Cimicidae) by solid phase microextraction, thin film microextraction and needle trap device.

    PubMed

    Eom, In-Yong; Risticevic, Sanja; Pawliszyn, Janusz

    2012-02-24

    Air in a room infested by Cimex lectularius L. (Hemiptera: Cimicidae) was sampled simultaneously by three different sampling devices including solid phase microextraction (SPME) fiber coatings, thin film microextraction (TFME) devices, and needle trap devices (NTDs) and then analyzed by gas chromatography-mass spectrometry (GC-MS). The main focus of this study was to fully characterize indoor air by identifying compounds extracted by three different microextraction formats and, therefore, perform both the device comparison and more complete characterization of C. lectularius pheromone. The NTD technique was capable of extracting both (E)-2-hexenal and (E)-2-octenal, which were previously identified as alarm pheromones of bedbugs, and superior NTD recoveries for these two components allowed reliable identification based on mass spectral library searching and linear temperature programmed retention index (LTPRI) technique. While the use of DVB/CAR/PDMS SPME fiber coatings provided complementary sample fingerprinting and profiling results, TFME sampling devices provided discriminative extraction coverage toward highly volatile analytes. In addition to two alarm pheromones, relative abundances of all other analytes were recorded for all three devices and aligned across all examined samples, namely, highly infested area, less infested area, and control samples which were characterized by different bedbug populations. The results presented in the current study illustrate comprehensive characterization of infested indoor air samples through the use of three different non-invasive SPME formats and identification of novel components comprising C. lectularius pheromone, therefore, promising future alternatives for use of potential synthetic pheromones for detection of infestations.

  4. 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.

  5. 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.

  6. Challenges associated with the sampling and analysis of organosulfur compounds in air using real-time PTR-ToF-MS and offline GC-FID

    NASA Astrophysics Data System (ADS)

    Perraud, Véronique; Meinardi, Simone; Blake, Donald R.; Finlayson-Pitts, Barbara J.

    2016-03-01

    Organosulfur compounds (OSCs) are naturally emitted via various processes involving phytoplankton and algae in marine regions, from animal metabolism, and from biomass decomposition inland. These compounds are malodorant and reactive. Their oxidation to methanesulfonic and sulfuric acids leads to the formation and growth of atmospheric particles, which are known to influence clouds and climate, atmospheric chemical processes. In addition, particles in air have been linked to negative impacts on visibility and human health. Accurate measurements of the OSC precursors are thus essential to reduce uncertainties in their sources and contributions to particle formation in air. Two different approaches, proton-transfer reaction time-of-flight mass spectrometry (PTR-ToF-MS) and canister sampling coupled to gas chromatography with flame ionization detector (GC-FID), are compared for both laboratory standards (dimethyl sulfide, DMS; dimethyl disulfide, DMDS; dimethyl trisulfide, DMTS; and methanethiol, MTO) and for a complex sample. Results show that both techniques produce accurate quantification of DMS. While PTR-ToF-MS provides real-time measurements of all four OSCs individually, significant fragmentation of DMDS and DMTS occurs, which can complicate their identification in complex mixtures. Canister sampling coupled with GC-FID provides excellent sensitivity for DMS, DMDS, and DMTS. However, MTO was observed to react on metal surfaces to produce DMDS and, in the presence of hydrogen sulfide, even DMTS. Avoiding metal in sampling systems seems to be necessary for measuring all but dimethyl sulfide in air.

  7. Revisiting sample entropy analysis

    NASA Astrophysics Data System (ADS)

    Govindan, R. B.; Wilson, J. D.; Eswaran, H.; Lowery, C. L.; Preißl, H.

    2007-03-01

    We modify the definition of sample entropy (SaEn) by incorporating a time delay between the components of the block (from which the densities are estimated) and show that the modified method characterizes the complexity of the system better than the original version. We apply the modified SaEn to the standard deterministic systems and stochastic processes (uncorrelated and long range correlated (LRC) processes) and show that the underlying complexity of the system is better quantified by the modified method. We extend this analysis to the RR intervals of the normal and congestive heart failure (CHF) subjects (available via www.physionet.org) and show that there is a good degree of separation between the two groups.

  8. Air Quality Analysis

    EPA Pesticide Factsheets

    This site provides information for air quality data analysts inside and outside EPA. Much of the information is in the form of documented analyses that support the review of the national air qualiyt standards.

  9. 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.

  10. 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.

  11. 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

  12. 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.

  13. Corn leaf nitrate reductase - A nontoxic alternative to cadmium for photometric nitrate determinations in water samples by air-segmented continuous-flow analysis

    USGS Publications Warehouse

    Patton, C.J.; Fischer, A.E.; Campbell, W.H.; Campbell, E.R.

    2002-01-01

    Development, characterization, and operational details of an enzymatic, air-segmented continuous-flow analytical method for colorimetric determination of nitrate + nitrite in natural-water samples is described. This method is similar to U.S. Environmental Protection Agency method 353.2 and U.S. Geological Survey method 1-2545-90 except that nitrate is reduced to nitrite by soluble nitrate reductase (NaR, EC 1.6.6.1) purified from corn leaves rather than a packed-bed cadmium reactor. A three-channel, air-segmented continuous-flow analyzer-configured for simultaneous determination of nitrite (0.020-1.000 mg-N/L) and nitrate + nitrite (0.05-5.00 mg-N/L) by the nitrate reductase and cadmium reduction methods-was used to characterize analytical performance of the enzymatic reduction method. At a sampling rate of 90 h-1, sample interaction was less than 1% for all three methods. Method detection limits were 0.001 mg of NO2- -N/L for nitrite, 0.003 mg of NO3-+ NO2- -N/L for nitrate + nitrite by the cadmium-reduction method, and 0.006 mg of NO3- + NO2- -N/L for nitrate + nitrite by the enzymatic-reduction method. Reduction of nitrate to nitrite by both methods was greater than 95% complete over the entire calibration range. The difference between the means of nitrate + nitrite concentrations in 124 natural-water samples determined simultaneously by the two methods was not significantly different from zero at the p = 0.05 level.

  14. Does Traffic-related Air Pollution Explain Associations of Aircraft and Road Traffic Noise Exposure on Children's Health and Cognition? A Secondary Analysis of the United Kingdom Sample From the RANCH Project

    PubMed Central

    Clark, Charlotte; Crombie, Rosanna; Head, Jenny; van Kamp, Irene; van Kempen, Elise; Stansfeld, Stephen A.

    2012-01-01

    The authors examined whether air pollution at school (nitrogen dioxide) is associated with poorer child cognition and health and whether adjustment for air pollution explains or moderates previously observed associations between aircraft and road traffic noise at school and children's cognition in the 2001–2003 Road Traffic and Aircraft Noise Exposure and Children's Cognition and Health (RANCH) project. This secondary analysis of a subsample of the United Kingdom RANCH sample examined 719 children who were 9–10 years of age from 22 schools around London's Heathrow airport for whom air pollution data were available. Data were analyzed using multilevel modeling. Air pollution exposure levels at school were moderate, were not associated with a range of cognitive and health outcomes, and did not account for or moderate associations between noise exposure and cognition. Aircraft noise exposure at school was significantly associated with poorer recognition memory and conceptual recall memory after adjustment for nitrogen dioxide levels. Aircraft noise exposure was also associated with poorer reading comprehension and information recall memory after adjustment for nitrogen dioxide levels. Road traffic noise was not associated with cognition or health before or after adjustment for air pollution. Moderate levels of air pollution do not appear to confound associations of noise on cognition and health, but further studies of higher air pollution levels are needed. PMID:22842719

  15. Does traffic-related air pollution explain associations of aircraft and road traffic noise exposure on children's health and cognition? A secondary analysis of the United Kingdom sample from the RANCH project.

    PubMed

    Clark, Charlotte; Crombie, Rosanna; Head, Jenny; van Kamp, Irene; van Kempen, Elise; Stansfeld, Stephen A

    2012-08-15

    The authors examined whether air pollution at school (nitrogen dioxide) is associated with poorer child cognition and health and whether adjustment for air pollution explains or moderates previously observed associations between aircraft and road traffic noise at school and children's cognition in the 2001-2003 Road Traffic and Aircraft Noise Exposure and Children's Cognition and Health (RANCH) project. This secondary analysis of a subsample of the United Kingdom RANCH sample examined 719 children who were 9-10 years of age from 22 schools around London's Heathrow airport for whom air pollution data were available. Data were analyzed using multilevel modeling. Air pollution exposure levels at school were moderate, were not associated with a range of cognitive and health outcomes, and did not account for or moderate associations between noise exposure and cognition. Aircraft noise exposure at school was significantly associated with poorer recognition memory and conceptual recall memory after adjustment for nitrogen dioxide levels. Aircraft noise exposure was also associated with poorer reading comprehension and information recall memory after adjustment for nitrogen dioxide levels. Road traffic noise was not associated with cognition or health before or after adjustment for air pollution. Moderate levels of air pollution do not appear to confound associations of noise on cognition and health, but further studies of higher air pollution levels are needed.

  16. 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.

  17. Challenges associated with the sampling and analysis of organosulfur compounds in air using real-time PTR-ToF-MS and off-line GC-FID

    NASA Astrophysics Data System (ADS)

    Perraud, V.; Meinardi, S.; Blake, D. R.; Finlayson-Pitts, B. J.

    2015-12-01

    Organosulfur compounds (OSC) are naturally emitted via various processes involving phytoplankton and algae in marine regions, from animal metabolism and from biomass decomposition inland. These compounds are malodorant and reactive. Their oxidation to methanesulfonic and sulfuric acids leads to the formation and growth of atmospheric particles, which are known to have negative effects on visibility, climate and human health. In order to predict particle formation events, accurate measurements of the OSC precursors are essential. Here, two different approaches, proton-transfer reaction time-of-flight mass spectrometry (PTR-ToF-MS) and canister sampling coupled with GC-FID are compared for both laboratory standards [dimethyl sulfide (DMS), dimethyl disulfide (DMDS), dimethyl trisulfide (DMTS) and methanethiol (MTO)] and for a complex sample. Results show that both techniques produce accurate quantification of DMS. While PTR-ToF-MS provides real-time measurements of all four OSCs individually, significant fragmentation of DMDS and DMTS occurs, which can complicate their identification in complex mixtures. Canister sampling coupled with GC-FID provides excellent sensitivity for DMS, DMDS and DMTS. However, MTO was observed to react on metal surfaces to produce DMDS and, in the presence of hydrogen sulfide, even DMTS. Avoiding metal in sampling systems seems to be necessary for measuring all but dimethyl sulfide in air.

  18. 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.

  19. Sampling for Chemical Analysis.

    ERIC Educational Resources Information Center

    Kratochvil, Byron; And Others

    1984-01-01

    This review, designed to make analysts aware of uncertainties introduced into analytical measurements during sampling, is organized under these headings: general considerations; theory; standards; and applications related to mineralogy, soils, sediments, metallurgy, atmosphere, water, biology, agriculture and food, medical and clinical areas, oil…

  20. Lunar sample analysis

    NASA Technical Reports Server (NTRS)

    Tittmann, B. R.

    1975-01-01

    Previous studies have shown that very small amounts of absorbed volatiles only removed by outgassing in high vacuum and elevated temperatures-drastically increase the internal friction in terrestrial analogs of lunar basalt. Recently room temperature Q values as high as 2000 were achieved by thorough outgassing procedures in 10 to the 8th power torr. Results are presented on Q measurements for lunar rock 70215.85, along with some data on the effect on Q of a variety of gases. Data show that substantially greater increases in Q are obtainable in a lunar rock sample than in the terrestrial analog samples studied, and that in addition to H2O other gases also can make non-negligible contributions to the internal friction.

  1. 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...

  2. 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.

  3. 24-HOUR DIFFUSIVE SAMPLING OF 1,3-BUTADIENE IN AIR ONTO CARBOPACK X SOLID ADSORBENT FOLLOWED BY THERMAL DESORPTION/GC/MS ANALYSIS - FEASIBILITY STUDY

    EPA Science Inventory

    Diffusive sampling of 1,3-butadiene for 24 hr onto the graphitic adsorbent Carbopack X packed in a stainless steel tube badge (6.3 mm o.d., 5 mm i.d., and 90 mm in length) with analysis by thermal desorption/gas chromatography (GC)/mass spectrometry (MS) has been evaluated in con...

  4. 24-HOUR DIFFUSIVE SAMPLING OF 1,3-BUTADIENE IN AIR ONTO CARBONPAK X SOLID ADSORBENT WITH THEMAL DESORPTION/GC/MS ANALYSIS - FEASIBILITY STUDIES

    EPA Science Inventory

    Diffusive sampling of 1,3-butadiene for 24 hours onto the graphitic adsorbent Carbopack X contained in a stainless steel tube badge (6.3 mm OD, 5 mm ID, and 90 mm in length) with analysis by thermal desorption/GC/MS has been evaluated in controlled tests. A test matrix of 42 tr...

  5. Analysis of Pet Coke Samples

    EPA Pesticide Factsheets

    EPA required KCBX to submit samples of the petroleum coke stored at their North and South Chicago terminals to EPA's Chicago Regional Laboratory for analysis of pollutant levels. Results will be compared to coal and pet coke sampled in Detroit.

  6. Installation Restoration Program Stage 3. McClellan Air Force Base, California. Remedial Investigation/Feasibility Study Groundwater Sampling and Analysis Program Data Summary

    DTIC Science & Technology

    1988-12-01

    INSTALLATION RESTORATION PROGRAM .. STAGE 3 X..::.. MCCLELLAN AIR FORCE BASE 71! rPREPARED BY: Radian Corporation 10395 Old Plbcerille Road...PREPARED FOR: .................HEADQUARTERS AFLIDEY WRIGHTPATTERSON AFB, OHIO 4543 R~ - - -1 .~~~...... Ajr..J .~ .......... United States Air Force... AIR FORCE HEAoQUARTERS SACRAMENTO AIR LOGISTICS CENTER (AFLC)0 ELLAN AIR FORCE BASE. CALIFORNIA S6112-1O REPLY TO t0i3 J I 989 ATTN OF: EK SUBJECT Third

  7. Automated Sample collection and Analysis unit

    SciTech Connect

    Latner, Norman; Sanderson, Colin G.; Negro, Vincent C.

    1999-03-31

    Autoramp is an atmospheric radionuclide collection and analysis unit designed for unattended operation. A large volume of air passes through one of 31 filter cartridges which is then moved from a sampling chamber and past a bar code reader, to a shielded enclosure. The collected dust-borne radionuclides are counted with a high resolution germanium gamma-ray detector. An analysis is made and the results are transmitted to a central station that can also remotely control the unit.

  8. [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.

  9. Temporal-spatial analysis of U.S.-Mexico border environmental fine and coarse PM air sample extract activity in human bronchial epithelial cells

    SciTech Connect

    Lauer, Fredine T.; Mitchell, Leah A.; Bedrick, Edward; McDonald, Jacob D.; Lee, Wen-Yee; Li, Wen-Whai; Olvera, Hector; Amaya, Maria A.; Berwick, Marianne; Gonzales, Melissa; Currey, Robert; Pingitore, Nicholas E.

    2009-07-01

    Particulate matter less than 10 {mu}m (PM10) has been shown to be associated with aggravation of asthma and respiratory and cardiopulmonary morbidity. There is also great interest in the potential health effects of PM2.5. Particulate matter (PM) varies in composition both spatially and temporally depending on the source, location and seasonal condition. El Paso County which lies in the Paso del Norte airshed is a unique location to study ambient air pollution due to three major points: the geological land formation, the relatively large population and the various sources of PM. In this study, dichotomous filters were collected from various sites in El Paso County every 7 days for a period of 1 year. The sampling sites were both distant and near border crossings, which are near heavily populated areas with high traffic volume. Fine (PM2.5) and Coarse (PM10-2.5) PM filter samples were extracted using dichloromethane and were assessed for biologic activity and polycyclic aromatic (PAH) content. Three sets of marker genes human BEAS2B bronchial epithelial cells were utilized to assess the effects of airborne PAHs on biologic activities associated with specific biological pathways associated with airway diseases. These pathways included in inflammatory cytokine production (IL-6, IL-8), oxidative stress (HMOX-1, NQO-1, ALDH3A1, AKR1C1), and aryl hydrocarbon receptor (AhR)-dependent signaling (CYP1A1). Results demonstrated interesting temporal and spatial patterns of gene induction for all pathways, particularly those associated with oxidative stress, and significant differences in the PAHs detected in the PM10-2.5 and PM2.5 fractions. Temporally, the greatest effects on gene induction were observed in winter months, which appeared to correlate with inversions that are common in the air basin. Spatially, the greatest gene expression increases were seen in extracts collected from the central most areas of El Paso which are also closest to highways and border crossings.

  10. Temporal-spatial analysis of U.S.-Mexico border environmental fine and coarse PM air sample extract activity in human bronchial epithelial cells.

    PubMed

    Lauer, Fredine T; Mitchell, Leah A; Bedrick, Edward; McDonald, Jacob D; Lee, Wen-Yee; Li, Wen-Whai; Olvera, Hector; Amaya, Maria A; Berwick, Marianne; Gonzales, Melissa; Currey, Robert; Pingitore, Nicholas E; Burchiel, Scott W

    2009-07-01

    Particulate matter less than 10 microm (PM10) has been shown to be associated with aggravation of asthma and respiratory and cardiopulmonary morbidity. There is also great interest in the potential health effects of PM2.5. Particulate matter (PM) varies in composition both spatially and temporally depending on the source, location and seasonal condition. El Paso County which lies in the Paso del Norte airshed is a unique location to study ambient air pollution due to three major points: the geological land formation, the relatively large population and the various sources of PM. In this study, dichotomous filters were collected from various sites in El Paso County every 7 days for a period of 1 year. The sampling sites were both distant and near border crossings, which are near heavily populated areas with high traffic volume. Fine (PM2.5) and Coarse (PM10-2.5) PM filter samples were extracted using dichloromethane and were assessed for biologic activity and polycyclic aromatic (PAH) content. Three sets of marker genes human BEAS2B bronchial epithelial cells were utilized to assess the effects of airborne PAHs on biologic activities associated with specific biological pathways associated with airway diseases. These pathways included in inflammatory cytokine production (IL-6, IL-8), oxidative stress (HMOX-1, NQO-1, ALDH3A1, AKR1C1), and aryl hydrocarbon receptor (AhR)-dependent signaling (CYP1A1). Results demonstrated interesting temporal and spatial patterns of gene induction for all pathways, particularly those associated with oxidative stress, and significant differences in the PAHs detected in the PM10-2.5 and PM2.5 fractions. Temporally, the greatest effects on gene induction were observed in winter months, which appeared to correlate with inversions that are common in the air basin. Spatially, the greatest gene expression increases were seen in extracts collected from the central most areas of El Paso which are also closest to highways and border crossings.

  11. 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.

  12. 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

  13. TEMPORAL-SPATIAL ANALYSIS OF U.S.- MEXICO BORDER ENVIRONMENTAL FINE AND COARSE PM AIR SAMPLE EXTRACT ACTIVITY IN HUMAN BRONCHIAL EPITHELIAL CELLS

    PubMed Central

    Lauer, Fredine T.; Mitchell, Leah A.; Bedrick, Edward; McDonald, Jacob D.; Lee, Wen-Yee; Li, Wen-Whai; Olvera, Hector; Amaya, Maria A.; Berwick, Marianne; Gonzales, Melissa; Currey, Robert; Pingitore, Nicholas E.; Burchiel, Scott W.

    2009-01-01

    Particulate matter less than 10 μm (PM10) has been shown to be associated with aggravation of asthma and respiratory and cardiopulmonary morbidity. There is also great interest in the potential health effects of PM 2.5. Particulate matter (PM) varies in composition both spatially and temporally depending on the source, location and seasonal condition. El Paso County which lies in the Paso del Norte airshed is a unique location to study ambient air pollution due to three major points: the geological land formation, the relatively large population and the various sources of PM. In this study, dichotomous filters were collected from various sites in El Paso County every seven days for a period of one year. The sampling sites were both distant and near border crossings, which are near heavily populated areas with high traffic volume. Fine (PM2.5) and Coarse (PM10-2.5) PM filter samples were extracted using dichloromethane and were assessed for biologic activity and polycyclic aromatic (PAH) content. Three sets of marker genes human BEAS2B bronchial epithelial cells were utilized to assess the effects of airborne PAHs on biologic activities associated with specific biological pathways associated with airway diseases. These pathways included in inflammatory cytokine production (IL-6, IL-8), oxidative stress (HMOX-1, NQO-1, ALDH3A1, AKR1C1), and aryl hydrocarbon receptor (AhR)-dependent signaling (CYP1A1). Results demonstrated interesting temporal and spatial patterns of gene induction for all pathways, particularly those associated with oxidative stress, and significant differences in the PAHs detected in the PM10-2.5 and PM 2.5 fractions. Temporally, the greatest effects on gene induction were observed in winter months, which appeared to correlate with inversions that are common in the air basin. Spatially, the greatest gene expression increases were seen in extracts collected from the central most areas of El Paso which are also closest to highways and border

  14. 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.

  15. 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

  16. Air Pollution. Part A: Analysis.

    ERIC Educational Resources Information Center

    Ledbetter, Joe O.

    Two facets of the engineering control of air pollution (the analysis of possible problems and the application of effective controls) are covered in this two-volume text. Part A covers Analysis, and Part B, Prevention and Control. (This review is concerned with Part A only.) This volume deals with the terminology, methodology, and symptomatology…

  17. 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

  18. Comparison of Sampling Probe and Thermal Desorber in Hazardous Air Pollutants on Site (HAPSITE) Extended Range (ER) for Analysis of Toxic Organic (TO)-15 Compounds

    DTIC Science & Technology

    2014-03-01

    mustard gases using a field-portable gas chromatograph-mass spectrometer. Forensic Toxicol, 24: 17–22, 2006.   Smith PA. Person-portable gas ...ABSTRACT The Hazardous Air Pollutants on Site (HAPSITE), a portable Gas Chromatograph-Mass Spectrometer (GCMS), has been used to detect, identify...2014.   Abstract     The Hazardous Air Pollutants on Site (HAPSITE), a portable gas chromatograph-mass spectrometer (GC-MS), has been used to detect

  19. 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.

  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. 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.

  2. GET electronics samples data analysis

    NASA Astrophysics Data System (ADS)

    Giovinazzo, J.; Goigoux, T.; Anvar, S.; Baron, P.; Blank, B.; Delagnes, E.; Grinyer, G. F.; Pancin, J.; Pedroza, J. L.; Pibernat, J.; Pollacco, E.; Rebii, A.; Roger, T.; Sizun, P.

    2016-12-01

    The General Electronics for TPCs (GET) has been developed to equip a generation of time projection chamber detectors for nuclear physics, and may also be used for a wider range of detector types. The goal of this paper is to propose first analysis procedures to be applied on raw data samples from the GET system, in order to correct for systematic effects observed on test measurements. We also present a method to estimate the response function of the GET system channels. The response function is required in analysis where the input signal needs to be reconstructed, in terms of time distribution, from the registered output samples.

  3. A needle trap device packed with a sol-gel derived, multi-walled carbon nanotubes/silica composite for sampling and analysis of volatile organohalogen compounds in air.

    PubMed

    Heidari, Mahmoud; Bahrami, Abdolrahman; Ghiasvand, Ali Reza; Shahna, Farshid Ghorbani; Soltanian, Ali Reza

    2013-06-27

    A needle trap device (NTD) packed with silica composite of multi-walled carbon nanotubes (MWCNTs) prepared based on sol-gel technique was utilized for sampling and analysis of volatile organohalogen compounds (HVOCs) in air. The performance of the NTD packed with MWCNTs/silica composite as sorbent was examined in a variety of sampling conditions and was compared with NTDs packed with PDMS as well as SPME with Carboxen/PDMS-coated fibers. The limit of detection of NTDs for the GC/MS detection system was 0.01-0.05 ng mL(-1) and the limit of quantitation was 0.04-0.18 ng mL(-1). The RSD were 1.1-7.8% for intra-NTD comparison intended for repeatability of technique. The NTD-MWCNTs/silica composite showed better analytical performances compared to the NTD-PDMS composite and had the same analytical performances when compared to the SPME-Carboxen/PDMS fibers. The results show that NTD-MWCNTs-GC/MS is a powerful technique for active sampling of occupational/environmental pollutants in air.

  4. 40 CFR 86.240-94 - Exhaust sample analysis.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 19 2013-07-01 2013-07-01 false Exhaust sample analysis. 86.240-94 Section 86.240-94 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS...-Duty Passenger Vehicles; Cold Temperature Test Procedures § 86.240-94 Exhaust sample analysis....

  5. 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.

  6. 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

  7. 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

  8. 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.

  9. 340 Representative sampling verification tank sampling and analysis plan

    SciTech Connect

    Olander, A.R., Westinghouse Hanford

    1996-08-21

    This Sampling and Analysis Plan contains requirements for characterizing the 340 vault tank 1. The objective of the sampling and characterization is to determine if the tank is homogeneous when agitated and which sampling method provides the most representative sample. A secondary objective is to collect and characterize solid samples.

  10. 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.

  11. 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.

  12. [Environmental investigation of ground water contamination at Wright-Patterson Air Force Base, Ohio]. Volume 3, Appendix A, Draft standard operating procedures and elements: Sampling and Analysis Plan (SAP): Phase 1, Task 4, Field Investigation, Draft

    SciTech Connect

    Not Available

    1991-10-01

    This report presents information concerning field procedures employed during the monitoring, well construction, well purging, sampling, and well logging at the Wright-Patterson Air Force Base. Activities were conducted in an effort to evaluate ground water contamination.

  13. 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.

  14. Environmental sampling and analysis in support of NTI-3

    SciTech Connect

    McGuire, R.R.; Harrar, J.E.; Haas, J.S.; Eagle, R.J.; Andresen, B.D.

    1991-04-06

    The third National Trail Inspection took place at the Monsanto Chemical Plant in Luling, Louisiana. In order to test the effectiveness of environmental sampling (soil, water and air) in determining the nature of the chemical process in a given production plant and to examine the distance from a process building that samples can effectively be taken, we needed to select some materials that constituted components of process streams. Three materials were selected: 1. isopropyl amine for air monitoring, 2. 4-nitrophenol, one of the precursors in the acetaminophen process, and 3. an intermediate in the production of glyphosate for ROUNDUP that is known simply as glyphosate intermediated. LLNL did not participate in the air sampling nor the analysis for isopropyl amine. This paper discussed the steps in this experiment including sample collection, sample workshop, sample analysis the results and discussion and the conclusion. 3 figs., 6 tabs.

  15. 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

  16. 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

  17. 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

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. [Comparison Test Between PM2.5 Continuous Monitoring System and Manual Sampling Analysis for PM2.5 in Ambient Air].

    PubMed

    Wang, Qiang; Zhong, Qi; Chi, Ying; Zhang, Yang; Yang, Kai

    2015-05-01

    According to the U. S. EPA performance index and detection methods for comparison test of PM2.5 continuous monitoring system, in combination of the current related technical specifications in China, 4 types of typical imported and domestic PM2.5 continuous monitoring system with two different principles were tested and compared to the manual sampling measurement (gravimetric method) in spring, summer, autumn and winter. This research determined the quality control requirements ( parallelism of manual sampling measurement results ≤ 5 µg · m(-3) or 5%), the technical index (slope of linearity regression equation 1 ± 0.15; intercept 0 ± 10; correlation coefficient ≥ 0.95), and corresponding detection methods of reference method comparison test to PM2.5 continuous monitoring system, which meets the requirement of current environmental quality status and environmental monitoring and management in China. It also provided technical means and method of quality control for effective use and data quality of PM2.5 continuous monitoring system in China.

  5. 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

  6. 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.

  7. 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

  8. Sample Manipulation System for Sample Analysis at Mars

    NASA Technical Reports Server (NTRS)

    Mumm, Erik; Kennedy, Tom; Carlson, Lee; Roberts, Dustyn

    2008-01-01

    The Sample Analysis at Mars (SAM) instrument will analyze Martian samples collected by the Mars Science Laboratory Rover with a suite of spectrometers. This paper discusses the driving requirements, design, and lessons learned in the development of the Sample Manipulation System (SMS) within SAM. The SMS stores and manipulates 74 sample cups to be used for solid sample pyrolysis experiments. Focus is given to the unique mechanism architecture developed to deliver a high packing density of sample cups in a reliable, fault tolerant manner while minimizing system mass and control complexity. Lessons learned are presented on contamination control, launch restraint mechanisms for fragile sample cups, and mechanism test data.

  9. Versatile microanalytical system with porous polypropylene capillary membrane for calibration gas generation and trace gaseous pollutants sampling applied to the analysis of formaldehyde, formic acid, acetic acid and ammonia in outdoor air.

    PubMed

    Coelho, Lúcia H G; Melchert, Wanessa R; Rocha, Flavio R; Rocha, Fábio R P; Gutz, Ivano G R

    2010-11-15

    The analytical determination of atmospheric pollutants still presents challenges due to the low-level concentrations (frequently in the μg m(-3) range) and their variations with sampling site and time. In this work, a capillary membrane diffusion scrubber (CMDS) was scaled down to match with capillary electrophoresis (CE), a quick separation technique that requires nothing more than some nanoliters of sample and, when combined with capacitively coupled contactless conductometric detection (C(4)D), is particularly favorable for ionic species that do not absorb in the UV-vis region, like the target analytes formaldehyde, formic acid, acetic acid and ammonium. The CMDS was coaxially assembled inside a PTFE tube and fed with acceptor phase (deionized water for species with a high Henry's constant such as formaldehyde and carboxylic acids, or acidic solution for ammonia sampling with equilibrium displacement to the non-volatile ammonium ion) at a low flow rate (8.3 nL s(-1)), while the sample was aspirated through the annular gap of the concentric tubes at 2.5 mL s(-1). A second unit, in all similar to the CMDS, was operated as a capillary membrane diffusion emitter (CMDE), generating a gas flow with know concentrations of ammonia for the evaluation of the CMDS. The fluids of the system were driven with inexpensive aquarium air pumps, and the collected samples were stored in vials cooled by a Peltier element. Complete protocols were developed for the analysis, in air, of NH(3), CH(3)COOH, HCOOH and, with a derivatization setup, CH(2)O, by associating the CMDS collection with the determination by CE-C(4)D. The ammonia concentrations obtained by electrophoresis were checked against the reference spectrophotometric method based on Berthelot's reaction. Sensitivity enhancements of this reference method were achieved by using a modified Berthelot reaction, solenoid micro-pumps for liquid propulsion and a long optical path cell based on a liquid core waveguide (LCW). All

  10. 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...

  11. 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...

  12. 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...

  13. 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

  14. 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

  15. 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.

  16. 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

  17. Sub-sampling and preparing forensic samples for pollen analysis.

    PubMed

    Horrocks, Mark

    2004-09-01

    The main forensic application of palynology is in providing associative evidence, assisting to prove or disprove a link between people and objects with places or with other people. Although identification and interpretation of pollen is a specialist job, sub-sampling and preparing pollen samples for analysis may be carried out by non-specialists. As few forensic laboratories have residing palynologists, laboratories may wish to reduce the cost of analysis or risk of contamination by doing their own sub-sampling and preparation. Presented is a practical guide for sub-sampling and preparing forensic samples for pollen analysis, providing a complete standard procedure for both the palynologist and non-specialist. Procedures for sub-sampling include a wide variety of materials commonly collected for forensic analysis (soil, clothing and other fabrics, footwear, twine and rope, firearms, granulated materials, plant and animal material, and illicit drugs), many of which palynologists will not be familiar with. Procedures for preparation of samples (pollen concentration) are presented as a detailed, step-by-step method. Minimizing the risks of laboratory and cross-sample contamination during sub-sampling and preparation is emphasized.

  18. 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 ...

  19. 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.

  20. Sampling and sample processing in pesticide residue analysis.

    PubMed

    Lehotay, Steven J; Cook, Jo Marie

    2015-05-13

    Proper sampling and sample processing in pesticide residue analysis of food and soil have always been essential to obtain accurate results, but the subject is becoming a greater concern as approximately 100 mg test portions are being analyzed with automated high-throughput analytical methods by agrochemical industry and contract laboratories. As global food trade and the importance of monitoring increase, the food industry and regulatory laboratories are also considering miniaturized high-throughput methods. In conjunction with a summary of the symposium "Residues in Food and Feed - Going from Macro to Micro: The Future of Sample Processing in Residue Analytical Methods" held at the 13th IUPAC International Congress of Pesticide Chemistry, this is an opportune time to review sampling theory and sample processing for pesticide residue analysis. If collected samples and test portions do not adequately represent the actual lot from which they came and provide meaningful results, then all costs, time, and efforts involved in implementing programs using sophisticated analytical instruments and techniques are wasted and can actually yield misleading results. This paper is designed to briefly review the often-neglected but crucial topic of sample collection and processing and put the issue into perspective for the future of pesticide residue analysis. It also emphasizes that analysts should demonstrate the validity of their sample processing approaches for the analytes/matrices of interest and encourages further studies on sampling and sample mass reduction to produce a test portion.

  1. 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

  2. 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

  3. 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.

  4. Sampling and sample processing in pesticide residue analysis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Proper sampling and sample processing in pesticide residue analysis of food and soil has always been essential to obtain accurate results, but the subject is becoming a greater concern as approximately 100 mg test portions are being analyzed with automated high-throughput analytical methods by agroc...

  5. IWTU Process Sample Analysis Report

    SciTech Connect

    Nick Soelberg

    2013-04-01

    CH2M-WG Idaho (CWI) requested that Battelle Energy Alliance (BEA) analyze various samples collected during June – August 2012 at the Integrated Waste Treatment Facility (IWTU). Samples of IWTU process materials were collected from various locations in the process. None of these samples were radioactive. These samples were collected and analyzed to provide more understanding of the compositions of various materials in the process during the time of the process shutdown that occurred on June 16, 2012, while the IWTU was in the process of nonradioactive startup.

  6. FIELD SAMPLING PROTOCOLS AND ANALYSIS

    EPA Science Inventory

    I have been asked to speak again to the environmental science class regarding actual research scenarios related to my work at Kerr Lab. I plan to discuss sampling protocols along with various field analyses performed during sampling activities. Many of the students have never see...

  7. 40 CFR 1065.1111 - Sample analysis.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 33 2014-07-01 2014-07-01 false Sample analysis. 1065.1111 Section... § 1065.1111 Sample analysis. This subpart does not specify chromatographic or analytical methods to... process by verifying the volume of sample injected for analysis....

  8. Sample collection, biobanking, and analysis.

    PubMed

    Ahsman, Maurice J; Tibboel, Dick; Mathot, Ron A A; de Wildt, Saskia N

    2011-01-01

    Pediatric pharmacokinetic studies require sampling of biofluids from neonates and children. Limitations on sampling frequency and sample volume complicate the design of these studies. In addition, strict guidelines, designed to guarantee patient safety, are in place. This chapter describes the practical implications of sample collection and their storage, with special focus on the selection of the appropriate type of biofluid and withdrawal technique. In addition, we describe appropriate measures for storage of these specimens, for example, in the context of biobanking, and the requirements on drug assay methods that they pose. Pharmacokinetic studies in children are possible, but they require careful selection of an appropriate sampling method, specimen volume, and assay method. The checklist provided could help prospective researchers with the design of an appropriate study protocol and infrastructure.

  9. 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

  10. 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

  11. 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

  12. 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

  13. 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

  14. 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

  15. 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

  16. 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

  17. 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

  18. 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

  19. 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

  20. 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

  1. 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

  2. ENGINEERING BULLETIN: AIR PATHWAY ANALYSIS

    EPA Science Inventory

    This bulletin presents information on estimating toxic air emissions from Superfund sites. The focus is on the collection of air emmissions data during the site inspection and remedial investigation/feasibility study and the use of these data for the selection or implementation o...

  3. 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.

  4. 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...

  5. 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.

  6. 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.

  7. Sample processor for chemical analysis

    NASA Technical Reports Server (NTRS)

    Boettger, Heinz G. (Inventor)

    1980-01-01

    An apparatus is provided which can process numerous samples that must be chemically analyzed by the application of fluids such as liquid reagents, solvents and purge gases, as well as the application of dumps for receiving the applied fluid after they pass across the sample, in a manner that permits numerous samples to be processed in a relatively short time and with minimal manpower. The processor includes a rotor which can hold numerous cartridges containing inert or adsorbent material for holding samples, and a pair of stators on opposite sides of the rotor. The stators form stations spaced along the path of the cartridges which lie in the rotor, and each station can include an aperture in one stator through which a fluid can be applied to a cartridge resting at that station, and an aperture in the other stator which can receive the fluid which has passed through the cartridge. The stators are sealed to the ends of the cartridges lying on the rotor, to thereby isolate the stations from one another.

  8. Microwave sample preparation for analysis of metals in environmental samples

    SciTech Connect

    Collins, L.W.

    1996-10-01

    The unique nature of microwave energy enhances heating efficiency and improves acid digestion sample preparation. Faster sample preparation and improved precision of the analysis occur. These results will be illustrated in this presentation using various standard reference materials and environmentally important samples. The analytical microwave system used offers accurate temperature and pressure feedback control through the use of a hand-held controller or PC-based control. Digestions are performed in patented, user-friendly microwave vessels. USEPA Method 3015, {open_quotes}Microwave-Assisted Acid Digestion of Aqueous Samples and Extracts,{close_quotes} is properly performed when the sample is heated to 170{degrees}C within 10 minutes, and maintained for an additional 10 minutes. USEPA Method 3051, {open_quotes}Microwave-Assisted Acid Digestion of Sediments, Sludges, Soils, and Oils,{close_quotes} is properly performed when the sample is heated to 175{degrees}C within 5.5 minutes, and maintained at 175{degrees}C for an additional 4.5 minutes. After the timesaving microwave digestion period, the samples were analyzed for metals by ICP-AES. Excellent accuracy and precision were obtained, in addition to 90% time reduction when using microwave sample preparation.

  9. Tank 12H residuals sample analysis report

    SciTech Connect

    Oji, L. N.; Shine, E. P.; Diprete, D. P.; Coleman, C. J.; Hay, M. S.

    2015-06-11

    The Savannah River National Laboratory (SRNL) was requested by Savannah River Remediation (SRR) to provide sample preparation and analysis of the Tank 12H final characterization samples to determine the residual tank inventory prior to grouting. Eleven Tank 12H floor and mound residual material samples and three cooling coil scrape samples were collected and delivered to SRNL between May and August of 2014.

  10. PIXE analysis of Nigerian flour and bread samples

    NASA Astrophysics Data System (ADS)

    Olise, Felix S.; Fernandes, Adriana M.; Cristina Chaves, P.; Taborda, Ana; Reis, Miguel A.

    2014-01-01

    The alleged use of potassium bromate (KBrO3) in bread baking led a few authors to report on the chemical methods for the determination of KBrO3 levels in bread. In order to examine the potentials of a non chemical particle induced X-ray emission (PIXE) method for this purpose, six sets of samples, each composed of flour, dough and bread from a production batch were analysed. The samples were obtained from six different bakers of bread at Ile-Ife, Nigeria. The flour samples were air-dried while others were freeze dried at about -16 °C. The samples were homogenised in an agate mortar and then pelletised. Samples were analysed at the CTN standard PIXE setup and standard procedures for thick target samples analysis were followed. In some samples significant concentrations of bromine were found. In the present work we present possible explanations for the presence of this potentially dangerous contaminant in the samples.

  11. REPRESENTATIVE SAMPLING AND ANALYSIS OF HETEROGENEOUS SOILS

    EPA Science Inventory

    Standard sampling and analysis methods for hazardous substances in contaminated soils currently are available and routinely employed. Standard methods inherently assume a homogeneous soil matrix and contaminant distribution; therefore only small sample quantities typically are p...

  12. 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)

  13. 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)

  14. 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.

  15. Visual Analysis of Air Traffic Data

    NASA Technical Reports Server (NTRS)

    Albrecht, George Hans; Pang, Alex

    2012-01-01

    In this paper, we present visual analysis tools to help study the impact of policy changes on air traffic congestion. The tools support visualization of time-varying air traffic density over an area of interest using different time granularity. We use this visual analysis platform to investigate how changing the aircraft separation volume can reduce congestion while maintaining key safety requirements. The same platform can also be used as a decision aid for processing requests for unmanned aerial vehicle operations.

  16. Energy analysis for a sample building by the proposed ASHRAE simplified method

    NASA Astrophysics Data System (ADS)

    Kasuda, T.; Ishii, K.

    1981-01-01

    An energy analysis of a sample office building located in Washington, DC using the proposed ASHRAE method is presented. Calculations for space load are presented. The calculations for the energy distribution systems (air conditioning, outdoor air control, humidity control, airduct systems) are given. Equipment system calculations, and calculations for the annual energy consumption for air conditioning are presented.

  17. HIGH SPEED GC/MS FOR AIR ANALYSIS

    EPA Science Inventory

    A high speed GC/MS system consisting of a gas chromatograph equipped with a narrow bandwidth injection accessory and using a time-of-flight mass spectrometer detector has been adapted for analysis of ambient whole air samples which have been collected in passivated canisters. ...

  18. DWPF GC FILTER ASSEMBLY SAMPLING AND ANALYSIS

    SciTech Connect

    Bannochie, C.; Imrich, K.

    2009-11-11

    On March 18, 2009 a Defense Waste Processing Facility (DWPF) GC Line Filter Assembly was received at the Savannah River National Laboratory (SRNL). This filter assembly was removed from operation following the completion of Sludge Batch 4 processing in the DWPF. Work on this sample was requested in a Technical Assistance Request. This document reports the pictures, observations, samples collected, and analytical results for the assembly. The assembly arrived at SRNL separated into its three component filters: high efficiency particulate air (HEPA)-1, HEPA-2, and a high efficiency mist evaporator (HEME). Each stage of the assembly's media was sampled and examined visually and by scanning electron microscopy (SEM). Solids built up in the filter housing following the first stage HEME, were dissolved in dilute nitric acid and analyzed by ICP-AES and the undissolved white solids were analyzed by x-ray diffraction (XRD). The vast majority of the material in each of the three stages of the DWPF GC Line Filter Assembly appears to be contaminated with a Hg compound that is {approx}59 wt% Hg on a total solids basis. The Hg species was identified by XRD analysis to contain a mixture of Hg{sub 4}(OH)(NO{sub 3}){sub 3} and Hg{sub 10}(OH){sub 4}(NO{sub 3}){sub 6}. Only in the core sample of the second stage HEPA, did this material appear to be completely covering portions of the filter media, possibly explaining the pressure drops observed by DWPF. The fact that the material migrates through the HEME filter and both HEPA filters, and that it was seen collecting on the outlet side of the HEME filter, would seem to indicate that these filters are not efficient at removing this material. Further SRAT off-gas system modeling should help determine the extent of Hg breakthrough past the Mercury Water Wash Tank (MWWT). The SRAT off-gas system has not been modeled since startup of the facility. Improvements to the efficiency of Hg stripping prior to the ammonia scrubber would seem to be

  19. 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.

  20. 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

  1. Systemic Analysis Approaches for Air Transportation

    NASA Technical Reports Server (NTRS)

    Conway, Sheila

    2005-01-01

    Air transportation system designers have had only limited success using traditional operations research and parametric modeling approaches in their analyses of innovations. They need a systemic methodology for modeling of safety-critical infrastructure that is comprehensive, objective, and sufficiently concrete, yet simple enough to be used with reasonable investment. The methodology must also be amenable to quantitative analysis so issues of system safety and stability can be rigorously addressed. However, air transportation has proven itself an extensive, complex system whose behavior is difficult to describe, no less predict. There is a wide range of system analysis techniques available, but some are more appropriate for certain applications than others. Specifically in the area of complex system analysis, the literature suggests that both agent-based models and network analysis techniques may be useful. This paper discusses the theoretical basis for each approach in these applications, and explores their historic and potential further use for air transportation analysis.

  2. 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.

  3. Application of response surface methodology for air assisted-dispersive liquid- liquid microextraction of deoxynivalenol in rice samples prior to HPLC-DAD analysis and comparison with solid phase extraction cleanup.

    PubMed

    Rahmani, Mashaallah; Ghasemi, Elham; Sasani, Mojtaba

    2017-04-01

    A fast, simple, and easy to operate air assisted-dispersive liquid-liquid microextraction (AA-DLLME) for preconcentration and extraction of deoxynivalenol (DON) from rice samples is proposed and compared with solid phase extraction (SPE) cleanup. DON was determined using a high performance liquid chromatography with diode-array detection (HPLC-DAD). AA-DLLME was performed using a glass syringe and dispersion of extractant in the sample solution was achieved with help of air bubbles. Chloroform was used as the extractant solvent. To find out the optimized condition for the proposed method, response surface methodology (RSM) was applied for multivariate optimization of effecting parameters namely volume of extractant, number of extraction, pH, and rate of centrifugation. Under optimized condition the dynamic range of calibration graph was found to be 50-500μgL(-1) with detection limit of 23.6μgL(-1). Both methods were applied for extraction of DON from rice.

  4. 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.

  5. Integrated sampling procedure for metabolome analysis.

    PubMed

    Schaub, Jochen; Schiesling, Carola; Reuss, Matthias; Dauner, Michael

    2006-01-01

    Metabolome analysis, the analysis of large sets of intracellular metabolites, has become an important systems analysis method in biotechnological and pharmaceutical research. In metabolic engineering, the integration of metabolome data with fluxome and proteome data into large-scale mathematical models promises to foster rational strategies for strain and cell line improvement. However, the development of reproducible sampling procedures for quantitative analysis of intracellular metabolite concentrations represents a major challenge, accomplishing (i) fast transfer of sample, (ii) efficient quenching of metabolism, (iii) quantitative metabolite extraction, and (iv) optimum sample conditioning for subsequent quantitative analysis. In addressing these requirements, we propose an integrated sampling procedure. Simultaneous quenching and quantitative extraction of intracellular metabolites were realized by short-time exposure of cells to temperatures < or =95 degrees C, where intracellular metabolites are released quantitatively. Based on these findings, we combined principles of heat transfer with knowledge on physiology, for example, turnover rates of energy metabolites, to develop an optimized sampling procedure based on a coiled single tube heat exchanger. As a result, this sampling procedure enables reliable and reproducible measurements through (i) the integration of three unit operations into a one unit operation, (ii) the avoidance of any alteration of the sample due to chemical reagents in quenching and extraction, and (iii) automation. A sampling frequency of 5 s(-)(1) and an overall individual sample processing time faster than 30 s allow observing responses of intracellular metabolite concentrations to extracellular stimuli on a subsecond time scale. Recovery and reliability of the unit operations were analyzed. Impact of sample conditioning on subsequent IC-MS analysis of metabolites was examined as well. The integrated sampling procedure was validated

  6. Sampling almonds for aflatoxin, part I: estimation of uncertainty associated with sampling, sample preparation, and analysis.

    PubMed

    Whitaker, Thomas B; Slate, Andrew B; Jacobs, Merle; Hurley, J Michael; Adams, Julie G; Giesbrecht, Francis G

    2006-01-01

    Domestic and international regulatory limits have been established for aflatoxin in almonds and other tree nuts. It is difficult to obtain an accurate and precise estimate of the true aflatoxin concentration in a bulk lot because of the uncertainty associated with the sampling, sample preparation, and analytical steps of the aflatoxin test procedure. To evaluate the performance of aflatoxin sampling plans, the uncertainty associated with sampling lots of shelled almonds for aflatoxin was investigated. Twenty lots of shelled almonds were sampled for aflatoxin contamination. The total variance associated with measuring B1 and total aflatoxins in bulk almond lots was estimated and partitioned into sampling, sample preparation, and analytical variance components. All variances were found to increase with an increase in aflatoxin concentration (both B1 and total). By using regression analysis, mathematical expressions were developed to predict the relationship between each variance component (total, sampling, sample preparation, and analysis variances) and aflatoxin concentration. Variance estimates were the same for B1 and total aflatoxins. The mathematical relationships can be used to estimate each variance for a given sample size, subsample size, and number of analyses other than that measured in the study. When a lot with total aflatoxins at 15 ng/g was tested by using a 10 kg sample, a vertical cutter mixer type of mill, a 100 g subsample, and high-performance liquid chromatography analysis, the sampling, sample preparation, analytical, and total variances (coefficient of variation, CV) were 394.7 (CV, 132.4%), 14.7 (CV, 25.5%), 0.8 (CV, 6.1%), and 410.2 (CV, 135.0%), respectively. The percentages of the total variance associated with sampling, sample preparation, and analytical steps were 96.2, 3.6, and 0.2, respectively.

  7. Statistical Analysis Techniques for Small Sample Sizes

    NASA Technical Reports Server (NTRS)

    Navard, S. E.

    1984-01-01

    The small sample sizes problem which is encountered when dealing with analysis of space-flight data is examined. Because of such a amount of data available, careful analyses are essential to extract the maximum amount of information with acceptable accuracy. Statistical analysis of small samples is described. The background material necessary for understanding statistical hypothesis testing is outlined and the various tests which can be done on small samples are explained. Emphasis is on the underlying assumptions of each test and on considerations needed to choose the most appropriate test for a given type of analysis.

  8. 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.

  9. 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

  10. 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

  11. 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.

  12. Analysis of enantiomeric and non-enantiomeric monoterpenes in plant emissions using portable dynamic air sampling/solid-phase microextraction (PDAS-SPME) and chiral gas chromatography/mass spectrometry

    NASA Astrophysics Data System (ADS)

    Yassaa, Noureddine; Williams, Jonathan

    A portable dynamic air sampler (PDAS) using a porous polymer solid-phase microextraction (SPME) fibre has been validated for the determination of biogenic enantiomeric and non-enantiomeric monoterpenes in air. These compounds were adsorbed in the field, and then thermally desorbed at 250 °C in a gas chromatograph injector port connected via a β-cyclodextrin capillary separating column to a mass spectrometer. The optimized method has been applied for investigating the emissions of enantiomeric monoterpenes from Pseudotsuga menziesii (Douglas-fir), Rosmarinus officinalis (Rosemary) and Lavandula lanata (Lavender) which were selected as representative of coniferous trees and aromatic plants, respectively. The enantiomers of α-pinene, sabinene, camphene, δ-3-carene, β-pinene, limonene, β-phellandrene, 4-carene and camphor were successfully determined in the emissions from the three plants. While Douglas-fir showed a strong predominance toward (-)-enantiomers, Rosemary and Lavender demonstrated a large variation in enantiomeric distribution of monoterpenes. The simplicity, rapidity and sensitivity of dynamic sampling with porous polymer coated SPME fibres coupled to chiral capillary gas chromatography/mass spectrometry (GC/MS) makes this method potentially useful for in-field investigations of atmosphere-biosphere interactions and studies of optically explicit atmospheric chemistry.

  13. 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.

  14. Fluidics platform and method for sample preparation and analysis

    SciTech Connect

    Benner, W. Henry; Dzenitis, John M.; Bennet, William J.; Baker, Brian R.

    2014-08-19

    Herein provided are fluidics platform and method for sample preparation and analysis. The fluidics platform is capable of analyzing DNA from blood samples using amplification assays such as polymerase-chain-reaction assays and loop-mediated-isothermal-amplification assays. The fluidics platform can also be used for other types of assays and analyzes. In some embodiments, a sample in a sealed tube can be inserted directly. The following isolation, detection, and analyzes can be performed without a user's intervention. The disclosed platform may also comprises a sample preparation system with a magnetic actuator, a heater, and an air-drying mechanism, and fluid manipulation processes for extraction, washing, elution, assay assembly, assay detection, and cleaning after reactions and between samples.

  15. 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.

  16. Field test of a generic method for the sampling and analysis of halogenated hydrocarbons listed in title III of the Clean Air Act amendments of 1990. Report for January 1992-December 1993

    SciTech Connect

    McGaughey, J.F.; Bursey, J.T.; Rice, J.; Merrill, R.G.; Jackson, M.D.

    1993-01-01

    To validate a new source test method for EPA use, the performance of the sampling and analytical methodology for the chemicals of interest must be established and demonstrated through field tests at sources similar to those of interest. Validation studies for measuring volatile and semi-volatile halogenated organics were undertaken in two different studies. Repeated sampling runs of the Volatile Organic Sample Train (VOST; SW-846 Sampling Method 0030 with Analytical Method 5041) and Semi-Volatile Organic Sample Train (Semi-VOST; SW-846 Method 0010 with Analytical Method 8270) were collected at two source locations. Quadruple sampling trains were used in each run, with two of the trains being spiked with standards. For the VOST method, the results of the two field studies were consistent with laboratory tests. For the Semi-VOST method, consistent results were obtained in the laboratory study and one of the field tests. At the second field site, the Semi-VOST data were inadequate because of problems encountered in preparation of the samples for analysis.

  17. 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

  18. Asbestos Workshop: Sampling, Analysis, and Risk Assessment

    DTIC Science & Technology

    2012-03-01

    fibrosis (fibrosis of the lining of the cavity holding the lungs) EMDQ March 2012 Chest x - ray showing areas of scarring related to asbestosis. 8...soil) •If the expected number of asbestos structures in a sample is λ, then the probability that there are exactly x asbestos fibers is equal to: •E.g...Estimating Risk for Asbestos Risk = Exposure x Toxicity = [Air] × ET × EF × IUR = f/cm3× hour/hour × day/day × (f/cm3)-1 For asbestos , ED is

  19. 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.

  20. Sampling hazelnuts for aflatoxin: uncertainty associated with sampling, sample preparation, and analysis.

    PubMed

    Ozay, Guner; Seyhan, Ferda; Yilmaz, Aysun; Whitaker, Thomas B; Slate, Andrew B; Giesbrecht, Francis

    2006-01-01

    The variability associated with the aflatoxin test procedure used to estimate aflatoxin levels in bulk shipments of hazelnuts was investigated. Sixteen 10 kg samples of shelled hazelnuts were taken from each of 20 lots that were suspected of aflatoxin contamination. The total variance associated with testing shelled hazelnuts was estimated and partitioned into sampling, sample preparation, and analytical variance components. Each variance component increased as aflatoxin concentration (either B1 or total) increased. With the use of regression analysis, mathematical expressions were developed to model the relationship between aflatoxin concentration and the total, sampling, sample preparation, and analytical variances. The expressions for these relationships were used to estimate the variance for any sample size, subsample size, and number of analyses for a specific aflatoxin concentration. The sampling, sample preparation, and analytical variances associated with estimating aflatoxin in a hazelnut lot at a total aflatoxin level of 10 ng/g and using a 10 kg sample, a 50 g subsample, dry comminution with a Robot Coupe mill, and a high-performance liquid chromatographic analytical method are 174.40, 0.74, and 0.27, respectively. The sampling, sample preparation, and analytical steps of the aflatoxin test procedure accounted for 99.4, 0.4, and 0.2% of the total variability, respectively.

  1. Electron spectroscopy for chemical analysis: Sample analysis

    NASA Technical Reports Server (NTRS)

    Carter, W. B.

    1989-01-01

    Exposure conditions in atomic oxygen (ESCA) was performed on an SSL-100/206 Small Spot Spectrometer. All data were taken with the use of a low voltage electron flood gun and a charge neutralization screen to minimize charging effects on the data. The X-ray spot size and electron flood gun voltage used are recorded on the individual spectra as are the instrumental resolutions. Two types of spectra were obtained for each specimen: (1) general surveys, and (2) high resolution spectra. The two types of data reduction performed are: (1) semiquantitative compositional analysis, and (2) peak fitting. The materials analyzed are: (1) kapton 4, 5, and 6, (2) HDPE 19, 20, and 21, and (3) PVDF 4, 5, and 6.

  2. Simultaneous analysis of oxygenated and nitrated polycyclic aromatic hydrocarbons on standard reference material 1649a (urban dust) and on natural ambient air samples by gas chromatography-mass spectrometry with negative ion chemical ionisation.

    PubMed

    Albinet, A; Leoz-Garziandia, E; Budzinski, H; Viilenave, E

    2006-07-14

    This study deals with the development of a routine analytical method using gas chromatography-mass spectrometry with negative ion chemical ionisation (GC/NICI-MS) for the determination of 17 nitrated polycyclic aromatic hydrocarbons (NPAHs) and 9 oxygenated polycyclic aromatic hydrocarbons (OPAHs) present at low concentrations in the atmosphere. This method includes a liquid chromatography purification procedure on solid-phase extraction (SPE) cartridge. Application of this analytical procedure has been performed on standard reference material (SRM 1649a: urban dust), giving results in good agreement with the few data available in the literature. The analytical method was also applied on ambient air samples (on both gas and particulate phases) from the French POVA program (POllution des Vallées Alpines). NPAHs concentrations observed for a rural site during the Winter period are about 0.2-100.0pgm(-3) in the particulate phase and about 0.0-20.0pgm(-3) in the gas phase. OPAHs present concentrations 10-100 times higher (0.1-2.0ngm(-3) and 0.0-1.4ngm(-3) for the particulate and the gas phases, respectively). These preliminary results show a good correlation between the characteristics of the sampling site and the compound origins (primary or secondary).

  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. 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

  5. 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...

  6. 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.

  7. 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…

  8. 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.

  9. 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.

  10. General aviation air traffic pattern safety analysis

    NASA Technical Reports Server (NTRS)

    Parker, L. C.

    1973-01-01

    A concept is described for evaluating the general aviation mid-air collision hazard in uncontrolled terminal airspace. Three-dimensional traffic pattern measurements were conducted at uncontrolled and controlled airports. Computer programs for data reduction, storage retrieval and statistical analysis have been developed. Initial general aviation air traffic pattern characteristics are presented. These preliminary results indicate that patterns are highly divergent from the expected standard pattern, and that pattern procedures observed can affect the ability of pilots to see and avoid each other.

  11. Air Force Materiel Command Reorganization Analysis

    DTIC Science & Technology

    2012-01-01

    Shelton, John A. Ausink, Chelsea Kaihoi Duran, Robert G. DeFeo, David W. George, Raymond E. Conley, Bernard Fox, Jerry M. Sollinger PROJECT AIR FORCE...Programs, and Analysis Director- ate (AFMC/A8/9); John Steenbock of the AFMC Manpower and Personnel Direc- torate (AFMC/A1); and others at Headquarters...Secretary of the Air Force for Logistics (SAF/IEL); Col John Dolan in the Office of the Legislative Liaison (SAF/LL); Col Jeffrey Morgan in the in

  12. Micropyrolyzer for chemical analysis of liquid and solid samples

    DOEpatents

    Mowry, Curtis D.; Morgan, Catherine H.; Manginell, Ronald P.; Frye-Mason, Gregory C.

    2006-07-18

    A micropyrolyzer has applications to pyrolysis, heated chemistry, and thermal desorption from liquid or solid samples. The micropyrolyzer can be fabricated from semiconductor materials and metals using standard integrated circuit technologies. The micropyrolyzer enables very small volume samples of less than 3 microliters and high sample heating rates of greater than 20.degree. C. per millisecond. A portable analyzer for the field analysis of liquid and solid samples can be realized when the micropyrolyzer is combined with a chemical preconcentrator, chemical separator, and chemical detector. Such a portable analyzer can be used in a variety of government and industrial applications, such as non-proliferation monitoring, chemical and biological warfare detection, industrial process control, water and air quality monitoring, and industrial hygiene.

  13. 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...

  14. 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...

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. Interlaboratory study of toxaphene analysis in ambient air

    NASA Astrophysics Data System (ADS)

    Bidleman, Terry F.; Cussion, Sylvia; Jantunen, Liisa M.

    An interlaboratory study was conducted for total toxaphene and selected congeners in an extract of ambient air from the southern United States. All participating labs were experienced in toxaphene analysis and used GC-MS techniques. Ten labs reported the concentration of total toxaphene in a technical toxaphene solution, with a 113% average recovery of the target value and 40% relative standard deviation (RSD). Only six of the 10 labs fell within ±30% of the target value, a criterion recommended by good laboratory practice standards. The interlaboratory RSD was 65% for total toxaphene in the air sample extract (lowered to 43% when one outlying lab was omitted). Nine labs reported the concentrations of five toxaphene components (B8-1413, B8-1414+B8-1945, B8-806+B8-809, B8-2229 and B9-1679) with 33-47% RSD for the technical toxaphene unknown and 34-62% for the air sample. The precision was poorer for a sixth component, congener B9-1025, which has a very low response by electron capture negative ion mass spectrometry (ECNI): 59% RSD for the technical toxaphene unknown and 196% for the air sample. Factors contributing to the interlaboratory variability for total toxaphene and single components are discussed, and follow-up studies are required to identify and minimize the causes of variability. Based on the average analysis, B8-1413 was enriched and B8-806+B8-809 was depleted in the air sample relative to the technical toxaphene standard.

  20. Longitudinal Metagenomic Analysis of Hospital Air Identifies Clinically Relevant Microbes

    PubMed Central

    King, Paula; Pham, Long K.; Waltz, Shannon; Sphar, Dan; Yamamoto, Robert T.; Conrad, Douglas; Taplitz, Randy; Torriani, Francesca

    2016-01-01

    We describe the sampling of sixty-three uncultured hospital air samples collected over a six-month period and analysis using shotgun metagenomic sequencing. Our primary goals were to determine the longitudinal metagenomic variability of this environment, identify and characterize genomes of potential pathogens and determine whether they are atypical to the hospital airborne metagenome. Air samples were collected from eight locations which included patient wards, the main lobby and outside. The resulting DNA libraries produced 972 million sequences representing 51 gigabases. Hierarchical clustering of samples by the most abundant 50 microbial orders generated three major nodes which primarily clustered by type of location. Because the indoor locations were longitudinally consistent, episodic relative increases in microbial genomic signatures related to the opportunistic pathogens Aspergillus, Penicillium and Stenotrophomonas were identified as outliers at specific locations. Further analysis of microbial reads specific for Stenotrophomonas maltophilia indicated homology to a sequenced multi-drug resistant clinical strain and we observed broad sequence coverage of resistance genes. We demonstrate that a shotgun metagenomic sequencing approach can be used to characterize the resistance determinants of pathogen genomes that are uncharacteristic for an otherwise consistent hospital air microbial metagenomic profile. PMID:27482891

  1. Longitudinal Metagenomic Analysis of Hospital Air Identifies Clinically Relevant Microbes.

    PubMed

    King, Paula; Pham, Long K; Waltz, Shannon; Sphar, Dan; Yamamoto, Robert T; Conrad, Douglas; Taplitz, Randy; Torriani, Francesca; Forsyth, R Allyn

    2016-01-01

    We describe the sampling of sixty-three uncultured hospital air samples collected over a six-month period and analysis using shotgun metagenomic sequencing. Our primary goals were to determine the longitudinal metagenomic variability of this environment, identify and characterize genomes of potential pathogens and determine whether they are atypical to the hospital airborne metagenome. Air samples were collected from eight locations which included patient wards, the main lobby and outside. The resulting DNA libraries produced 972 million sequences representing 51 gigabases. Hierarchical clustering of samples by the most abundant 50 microbial orders generated three major nodes which primarily clustered by type of location. Because the indoor locations were longitudinally consistent, episodic relative increases in microbial genomic signatures related to the opportunistic pathogens Aspergillus, Penicillium and Stenotrophomonas were identified as outliers at specific locations. Further analysis of microbial reads specific for Stenotrophomonas maltophilia indicated homology to a sequenced multi-drug resistant clinical strain and we observed broad sequence coverage of resistance genes. We demonstrate that a shotgun metagenomic sequencing approach can be used to characterize the resistance determinants of pathogen genomes that are uncharacteristic for an otherwise consistent hospital air microbial metagenomic profile.

  2. 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...

  3. 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

  4. Analysis of modified wet-air oxidation for soil detoxification

    SciTech Connect

    Unterberg, W.; Willms, R.S.; Balinsky, A.M.; Reible, D.D.; Wetzel, D.M.

    1987-09-01

    This report presents the results of research on wet-air oxidation as a method for the destruction of hazardous wastes. For organics in the presence of large amounts of water, the water need not be vaporized during wet-air oxidation, an attractive characteristic for energy conservation. The feasibility of using wet-air oxidation was investigated in terms of the effects of temperature, pressure, and the presence or absence of soil on the oxidation rate of three model compounds. Wet-air oxidation is a semi-commercial process that has been used to treat a variety of weakly toxic chemical wastes and for the regeneration of activated carbon. In the study, wet-air oxidation research was carried out in a 1-liter batch reactor at temperatures from 130 to 275/sup 0/C and pressures from 703-1760 x 10/sup 3/ kg/sq m on three substances: m-xylene, tetrachloroethylene (TCE), and malathion, both with and without addition of soil. Any attempt to balance the effect of residence time and the cost of energy requires an accurate description of the oxidation kinetics for the compound or waste stream in question. Due to the sampling technique used during the investigation and the inherent nature of the wet-air oxidation process, a variety of potential problems with the interpretation and analysis of the raw concentration-time data were encountered during the study.

  5. Simultaneous analysis of organochlorine pesticides and polychlorinated biphenyls in air samples by using accelerated solvent extraction (ASE) and solid-phase micro-extraction (SPME) coupled to gas chromatography dual electron capture detection.

    PubMed

    Mokbel, Haifaa; Al Dine, Enaam Jamal; Elmoll, Ahmad; Liaud, Céline; Millet, Maurice

    2016-04-01

    An analytical method associating accelerated solvent extraction (ASE) and solid-phase micro-extraction (SPME) in immersion mode combined with gas chromatography dual electrons capture detectors (SPME-GC-2ECD) has been developed and studied for the simultaneous determination of 19 organochlorine pesticides (OCPs) and 22 polychlorinated biphenyls (PCBs) in air samples (active and XAD-2 passive samplers). Samples were extracted with ASE with acetonitrile using the following conditions: temperature, 150 °C; pressure, 1500 psi; static, 15 min; cycles, 3; purge, 300 s; flush, 100 %. Extracts were reduced to 1 mL, and 500 μL of this extract, filled with deionised water, was subject to SPME extraction. Experimental results indicated that the proposed method attained the best extraction efficiency under the optimised conditions: extraction of PCB-OCP mixture using 100-μm PDMS fibre at 80 °C for 40 min with no addition of salt. The performance of the proposed ASE-SPME-GC-2ECD methodology with respect to linearity, limit of quantification and detection was evaluated by spiking of XAD-2 resin with target compounds. The regression coefficient (R (2)) of most compounds was found to be high of 0.99. limits of detection (LODs) are between 0.02 and 4.90 ng m(-3), and limits of quantification (LOQs) are between 0.05 and 9.12 ng m(-3) and between 0.2 and 49 ng/sampler and 0.52 and 91 ng/sampler, respectively, for XAD-2 passive samplers. Finally, a developed procedure was applied to determine selected PCBs and OCPs in the atmosphere.

  6. Method for preconcentrating a sample for subsequent analysis

    DOEpatents

    Zaromb, Solomon

    1990-01-01

    A system for analysis of trace concentration of contaminants in air includes a portable liquid chromatograph and a preconcentrator for the contaminants to be analyzed. The preconcentrator includes a sample bag having an inlet valve and an outlet valve for collecting an air sample. When the sample is collected the sample bag is connected in series with a sorbing apparatus in a recirculation loop. The sorbing apparatus has an inner gas-permeable container containing a sorbent material and an outer gas-impermeable container. The sample is circulated through the outer container and around the inner container for trapping and preconcentrating the contaminants in the sorbent material. The sorbent material may be a liquid having the same composition as the mobile phase of the chromatograph for direct injection thereinto. Alternatively, the sorbent material may be a porous, solid body, to which mobile phase liquid is added after preconcentration of the contaminants for dissolving the contaminants, the liquid solution then being withdrawn for injection into the chromatograph.

  7. 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.

  8. Double Shell Tank (DST) Ventilation System Vapor Sampling and Analysis Plan

    SciTech Connect

    SASAKI, L.M.

    2000-06-08

    This sampling and analysis plan (SAP) identifies characterization objectives pertaining to sample collection, laboratory analytical evaluation, and reporting requirements for vapor samples from the primary ventilation systems of the AN, AP, AW, and AY/AZ tank farms. Sampling will be performed in accordance with Data Quality Objectives for Regulatory Requirements for Hazardous and Radioactive Air Emissions Sampling and Analysis (Air DQO) (Mulkey 1999). The sampling will verify if current air emission estimates used in the permit application are correct and provide information for future air permit applications. Vapor samples will be obtained from tank farm ventilation systems, downstream from the tanks and upstream of any filtration. Samples taken in support of the DQO will consist of SUMMA{trademark} canisters, triple sorbent traps (TSTs), sorbent tube trains (STTs), polyurethane foam (PUF) samples. Particulate filter samples and tritium traps will be taken for radiation screening to allow the release of the samples for analysis. The following sections provide the general methodology and procedures to be used in the preparation, retrieval, transport, analysis, and reporting of results from the vapor samples.

  9. Sampling of illicit drugs for quantitative analysis--part III: sampling plans and sample preparations.

    PubMed

    Csesztregi, T; Bovens, M; Dujourdy, L; Franc, A; Nagy, J

    2014-08-01

    The findings in this paper are based on the results of our drug homogeneity studies and particle size investigations. Using that information, a general sampling plan (depicted in the form of a flow-chart) was devised that could be applied to the quantitative instrumental analysis of the most common illicit drugs: namely heroin, cocaine, amphetamine, cannabis resin, MDMA tablets and herbal cannabis in 'bud' form (type I). Other more heterogeneous forms of cannabis (type II) were found to require alternative, more traditional sampling methods. A table was constructed which shows the sampling uncertainty expected when a particular number of random increments are taken and combined to form a single primary sample. It also includes a recommended increment size; which is 1 g for powdered drugs and cannabis resin, 1 tablet for MDMA and 1 bud for herbal cannabis in bud form (type I). By referring to that table, individual laboratories can ensure that the sampling uncertainty for a particular drug seizure can be minimised, such that it lies in the same region as their analytical uncertainty for that drug. The table shows that assuming a laboratory wishes to quantitatively analyse a seizure of powdered drug or cannabis resin with a 'typical' heterogeneity, a primary sample of 15×1 g increments is generally appropriate. The appropriate primary sample for MDMA tablets is 20 tablets, while for herbal cannabis (in bud form) 50 buds were found to be appropriate. Our study also showed that, for a suitably homogenised primary sample of the most common powdered drugs, an analytical sample size of between 20 and 35 mg was appropriate and for herbal cannabis the appropriate amount was 200 mg. The need to ensure that the results from duplicate or multiple incremental sampling were compared, to demonstrate whether or not a particular seized material has a 'typical' heterogeneity and that the sampling procedure applied has resulted in a 'correct sample', was highlighted and the setting

  10. Analysis of Picattiny Sample for Trace Explosives

    SciTech Connect

    Klunder, G; Whipple, R; Carman, L; Spackman, P E; Reynolds, J; Alcaraz, A

    2008-05-23

    The sample received from Picatinny Arsenal was analyzed for trace amounts of high explosives (HE). A complete wash of the surface was performed, concentrated, and analyzed using two sensitive analysis techniques that are capable of detecting numerous types of explosives. No explosives were detected with either test.

  11. Exploratory Factor Analysis with Small Sample Sizes

    ERIC Educational Resources Information Center

    de Winter, J. C. F.; Dodou, D.; Wieringa, P. A.

    2009-01-01

    Exploratory factor analysis (EFA) is generally regarded as a technique for large sample sizes ("N"), with N = 50 as a reasonable absolute minimum. This study offers a comprehensive overview of the conditions in which EFA can yield good quality results for "N" below 50. Simulations were carried out to estimate the minimum required "N" for different…

  12. 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.

  13. Environmental Analysis of the Air Bending Process

    NASA Astrophysics Data System (ADS)

    Kellens, Karel; Dewulf, Wim; Duflou, Joost R.

    2011-05-01

    This paper presents the results of a data collection effort, allowing to assess the overall environmental impact of the air bending process using the CO2PE!-Methodology. First the different modes of the air bending process are investigated, including both productive and non-productive modes. In particular consumption of electric power is recorded for the different modes. Subsequently, time studies allow determining the importance of productive and nonproductive modes of the involved process. The study demonstrates that the influence of standby losses can be substantial. In addition to life cycle analysis, in depth process analysis also provides insight in achievable environmental impact reducing measures towards machine tool builders and eco-design recommendations for product developers. The energy consumption of three different machine tool architectures are analysed and compared within this paper.

  14. A Return on Investment Analysis of Air Force Officer Accessions

    DTIC Science & Technology

    2014-02-13

    AIR WAR COLLEGE AIR UNIVERSITY A RETURN ON INVESTMENT ANALYSIS OF AIR FORCE OFFICER ACCESSIONS by David O’Malley, LtCol, USAF...Lieutenant Colonel David O’Malley is assigned to the Air War College , Air University, Maxwell AFB, AL. Before attending the Air War College , LtCol O’Malley...the candidate’s junior and senior years of college , and a non-scholarship program. 3 Upon graduating from college , all ROTC candidates receive a four

  15. TEGA Sample Delivery and Analysis (Animation)

    NASA Technical Reports Server (NTRS)

    2008-01-01

    [figure removed for brevity, see original site] Click on image for animation

    This animation shows NASA's Phoenix Lander's Robotic Arm scoop delivering a sample to the Thermal and Evolved-Gas Analyzer (TEGA) and how samples are analyzed within the instrument.

    TEGA has eight tiny ovens for measuring constituents in the atmosphere and in the soil, including possible organic constituents and the melting point of ice.

    The scoop drops soil onto a fine mesh screen between TEGA's open doors. Some soil passes through the screen, which vibrates, into the throat of a funnel, where a spinning device called the 'whirligig' aids delivery into one half of a tiny oven. The soil sample is represented here by the white chip. The filled oven half then rotates and mates with the other oven half, closing the complete oven so sample heating can begin. The purple coil in this animation is the spring that moves the oven halves together.

    Heating occurs at successively higher temperatures over several days. The energy required to heat the sample is measured to discover its thermal properties. Gases driven off during sample heating pass through tubing to the mass spectrometer for analysis.

    Note that the exterior doors above the screen never close after sample delivery.

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASAaE(TM)s Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  16. Animation of TEGA Sample Delivery and Analysis

    NASA Technical Reports Server (NTRS)

    2008-01-01

    [figure removed for brevity, see original site] Click on image to view the animation

    This animation shows NASA's Phoenix Lander's Robotic Arm scoop delivering a sample to the Thermal and Evolved-Gas Analyzer (TEGA) and how samples are analyzed within the instrument.

    TEGA has eight tiny ovens for measuring constituents in the atmosphere and in the soil, including possible organic constituents and the melting point of ice.

    The scoop drops soil onto a fine mesh screen between TEGA's open doors. Some soil passes through the screen, which vibrates, into the throat of a funnel, where a spinning device called the 'whirligig' aids delivery into one half of a tiny oven. The soil sample is represented here by the white chip. The filled oven half then rotates and mates with the other oven half, closing the complete oven so sample heating can begin. The purple coil in this animation is the spring that moves the oven halves together.

    Heating occurs at successively higher temperatures over several days. The energy required to heat the sample is measured to discover its thermal properties. Gases driven off during sample heating pass through tubing to the mass spectrometer for analysis.

    Note that the exterior doors above the screen never close after sample delivery.

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  17. 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.

  18. 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.

  19. 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

  20. 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.

  1. 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.

  2. 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…

  3. 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...

  4. 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...

  5. 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.

  6. Germanium-76 Sample Analysis: Revision 3

    SciTech Connect

    Kouzes, Richard T.; Zhu, Zihua; Engelhard, Mark H.

    2011-09-19

    The MAJORANA DEMONSTRATOR is a large array of ultra-low background high-purity germanium detectors, enriched in 76Ge, designed to search for zero-neutrino double-beta decay (0{nu}{beta}{beta}). The DEMONSTRATOR will utilize 76Ge from Russia. The first one-gram sample was received from the supplier for analysis on April 24, 2011. The second one-gram sample was received from the supplier for analysis on July 12, 2011. The third sample, which came from the first large shipment of germanium from the vendor, was received from Oak Ridge National Laboratory (ORNL) on September 13, 2011. The Environmental Molecular Sciences facility, a DOE user facility at PNNL, was used to make the required isotopic and chemical purity measurements that are essential to the quality assurance for the MAJORANA DEMONSTRATOR. The results of these analyses are reported here. The isotopic composition of a sample of natural germanium was also measured twice. Differences in the result between these two measurements led to a re-measurement of the second 76Ge sample.

  7. QA/QC requirements for physical properties sampling and analysis

    SciTech Connect

    Innis, B.E.

    1993-07-21

    This report presents results of an assessment of the available information concerning US Environmental Protection Agency (EPA) quality assurance/quality control (QA/QC) requirements and guidance applicable to sampling, handling, and analyzing physical parameter samples at Comprehensive Environmental Restoration, Compensation, and Liability Act (CERCLA) investigation sites. Geotechnical testing laboratories measure the following physical properties of soil and sediment samples collected during CERCLA remedial investigations (RI) at the Hanford Site: moisture content, grain size by sieve, grain size by hydrometer, specific gravity, bulk density/porosity, saturated hydraulic conductivity, moisture retention, unsaturated hydraulic conductivity, and permeability of rocks by flowing air. Geotechnical testing laboratories also measure the following chemical parameters of soil and sediment samples collected during Hanford Site CERCLA RI: calcium carbonate and saturated column leach testing. Physical parameter data are used for (1) characterization of vadose and saturated zone geology and hydrogeology, (2) selection of monitoring well screen sizes, (3) to support modeling and analysis of the vadose and saturated zones, and (4) for engineering design. The objectives of this report are to determine the QA/QC levels accepted in the EPA Region 10 for the sampling, handling, and analysis of soil samples for physical parameters during CERCLA RI.

  8. OVERVIEW OF BERYLLIUM SAMPLING AND ANALYSIS

    SciTech Connect

    Brisson, M

    2009-04-01

    Because of its unique properties as a lightweight metal with high tensile strength, beryllium is widely used in applications including cell phones, golf clubs, aerospace, and nuclear weapons. Beryllium is also encountered in industries such as aluminium manufacturing, and in environmental remediation projects. Workplace exposure to beryllium particulates is a growing concern, as exposure to minute quantities of anthropogenic forms of beryllium may lead to sensitization and to chronic beryllium disease, which can be fatal and for which no cure is currently known. Furthermore, there is no known exposure-response relationship with which to establish a 'safe' maximum level of beryllium exposure. As a result, the current trend is toward ever lower occupational exposure limits, which in turn make exposure assessment, both in terms of sampling and analysis, more challenging. The problems are exacerbated by difficulties in sample preparation for refractory forms of beryllium, such as beryllium oxide, and by indications that some beryllium forms may be more toxic than others. This chapter provides an overview of sources and uses of beryllium, health risks, and occupational exposure limits. It also provides a general overview of sampling, analysis, and data evaluation issues that will be explored in greater depth in the remaining chapters. The goal of this book is to provide a comprehensive resource to aid personnel in a wide variety of disciplines in selecting sampling and analysis methods that will facilitate informed decision-making in workplace and environmental settings.

  9. Incorporating principal component analysis into air quality ...

    EPA Pesticide Factsheets

    The efficacy of standard air quality model evaluation techniques is becoming compromised as the simulation periods continue to lengthen in response to ever increasing computing capacity. Accordingly, the purpose of this paper is to demonstrate a statistical approach called Principal Component Analysis (PCA) with the intent of motivating its use by the evaluation community. One of the main objectives of PCA is to identify, through data reduction, the recurring and independent modes of variations (or signals) within a very large dataset, thereby summarizing the essential information of that dataset so that meaningful and descriptive conclusions can be made. In this demonstration, PCA is applied to a simple evaluation metric – the model bias associated with EPA's Community Multi-scale Air Quality (CMAQ) model when compared to weekly observations of sulfate (SO42−) and ammonium (NH4+) ambient air concentrations measured by the Clean Air Status and Trends Network (CASTNet). The advantages of using this technique are demonstrated as it identifies strong and systematic patterns of CMAQ model bias across a myriad of spatial and temporal scales that are neither constrained to geopolitical boundaries nor monthly/seasonal time periods (a limitation of many current studies). The technique also identifies locations (station–grid cell pairs) that are used as indicators for a more thorough diagnostic evaluation thereby hastening and facilitating understanding of the prob

  10. Sampling and Data Analysis for Environmental Microbiology

    SciTech Connect

    Murray, Christopher J.

    2001-06-01

    A brief review of the literature indicates the importance of statistical analysis in applied and environmental microbiology. Sampling designs are particularly important for successful studies, and it is highly recommended that researchers review their sampling design before heading to the laboratory or the field. Most statisticians have numerous stories of scientists who approached them after their study was complete only to have to tell them that the data they gathered could not be used to test the hypothesis they wanted to address. Once the data are gathered, a large and complex body of statistical techniques are available for analysis of the data. Those methods include both numerical and graphical techniques for exploratory characterization of the data. Hypothesis testing and analysis of variance (ANOVA) are techniques that can be used to compare the mean and variance of two or more groups of samples. Regression can be used to examine the relationships between sets of variables and is often used to examine the dependence of microbiological populations on microbiological parameters. Multivariate statistics provides several methods that can be used for interpretation of datasets with a large number of variables and to partition samples into similar groups, a task that is very common in taxonomy, but also has applications in other fields of microbiology. Geostatistics and other techniques have been used to examine the spatial distribution of microorganisms. The objectives of this chapter are to provide a brief survey of some of the statistical techniques that can be used for sample design and data analysis of microbiological data in environmental studies, and to provide some examples of their use from the literature.

  11. 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.

  12. Nano-FTIR for Geochemical Sample Analysis

    NASA Astrophysics Data System (ADS)

    Dominguez, G.; McCleod, A.; Gainsforth, Z.; Keilmann, F.; Westphal, A.; Thiemens, M. H.; Basov, D.

    2014-12-01

    Infrared (IR) spectroscopy is considered by many to be the "gold standard" for chemical identification, providing a direct connection between chemical compounds found in the laboratory and those found in natural samples including remote astrophysical environments. However, a well known limitation of using conventional IR spectroscopy is its spatial resolution determined by the wavelength of IR photons. Thus, while other techniques such as XANES and micro-Raman are capable of limited functional group mapping at tens to hundreds of nanometers, their use is limited by accessibility (the need for synchrotron beamlines) or the need for intense irradiation conditions (Raman) that can lead to sample alteration. These limitations and the wealth of information that can be extracted from detailed studies of unique micron-sized samples brought back by recent sample return missions such as NASA's Stardust mission, have motivated the development of a novel infrared mapping technique that is capable of mapping the chemical functional properties of geochemical samples with submicron resolutions. Here we describe our nano-FTIR imaging and analysis technique that allows us to bypass diffraction limited sample imaging in the infrared. Here we show, for the first time, that 1) the combination of an atomic-force microscope (AFM) and laser can be used to obtain the FTIR-equivalent spectra on spatial scales that are much smaller than the wavelength of IR radiation used 2) this technique responds to subtle shifts in cation concentrations as evidenced by changes in the frequencies of phonons at sub-micron scales 3) this technique can be used to identify regions of crystalline and semi-crystalline materials as demonstrated in our analysis of a cometary dust grain Iris. This work has clear implications for interpretations of astronomical observations and adds a new technique for the non-destructive characterization of terrestrial and extraterrestrial samples.

  13. BACTERIOLOGICAL ANALYSIS WITH SAMPLING AND SAMPLE PRESERVATION SPECIFICS

    EPA Science Inventory

    Current federal regulations (40CFR 503) specify that under certain conditions treated municipal biosolids must be analyzed for fecal coliform or salmonellae. The regulations state that representative samples of biosolids must be collected and analyzed using standard methods. Th...

  14. 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.

  15. Astrobiology Sample Analysis as a Design Driver

    NASA Technical Reports Server (NTRS)

    Cohen, Marc M.

    2001-01-01

    This effort supports the Astrobiology Objective 8 the Search for LIFE ON MARS PAST AND PRESENT -(Astrobiology Program Office, 1998, p.7). The essential trade analysis is between returning very small samples to the Earth while protecting them versus in situ analysis on Mars. Developing these explicit parameters encompasses design, instrumentation, system integration, human factors and surface operations for both alternatives. This allocation of capability approach incorporates a "humans and machines in the loop" model that recognizes that every exploration system involves both humans and automated systems. The question is where in the loop they occur whether on Earth, in the Mars Base, in the rover or creeping over the Mars surface.

  16. Miniaturization in sample treatment for environmental analysis.

    PubMed

    Ramos, L; Ramos, J J; Brinkman, U A Th

    2005-01-01

    The increasing demand for faster, more cost-effective and environmentally friendly analytical methods is a major incentive to improve the classical procedures used for sample treatment in environmental analysis. In most classical procedures, the use of rapid and powerful instrumental techniques for the final separation and detection of the analytes contrasts with the time-consuming and usually manual methods used for sample preparation, which slows down the total analytical process. The efforts made in this field in the past ten years have led to the adaptation of existing methods and the development of new techniques to save time and chemicals, and improve overall performance. One route has been to develop at-line or on-line and, frequently, automated systems. In these approaches, miniaturization has been a key factor in designing integrated analytical systems to provide higher sample throughput and/or unattended operation. Selected examples of novel developments in the field of miniaturized sample preparation for environmental analysis are used to evaluate the merits of the various techniques on the basis of published data on real-life analyses of trace-level organic pollutants. Perspectives and trends are briefly discussed.

  17. Analysis of particulates on tape lift samples

    NASA Astrophysics Data System (ADS)

    Moision, Robert M.; Chaney, John A.; Panetta, Chris J.; Liu, De-Ling

    2014-09-01

    Particle counts on tape lift samples taken from a hardware surface exceeded threshold requirements in six successive tests despite repeated cleaning of the surface. Subsequent analysis of the particle size distributions of the failed tests revealed that the handling and processing of the tape lift samples may have played a role in the test failures. In order to explore plausible causes for the observed size distribution anomalies, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and time-of-flight secondary ion mass spectrometry (ToF-SIMS) were employed to perform chemical analysis on collected particulates. SEM/EDX identified Na and S containing particles on the hardware samples in a size range identified as being responsible for the test failures. ToF-SIMS was employed to further examine the Na and S containing particulates and identified the molecular signature of sodium alkylbenzene sulfonates, a common surfactant used in industrial detergent. The root cause investigation suggests that the tape lift test failures originated from detergent residue left behind on the glass slides used to mount and transport the tape following sampling and not from the hardware surface.

  18. 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).

  19. 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.

  20. Mars Analogue Field Research and Sample Analysis

    NASA Astrophysics Data System (ADS)

    Foing, Bernard H.

    2016-07-01

    We describe results from the data analysis from a series of field research campaigns (ILEWG EuroMoonMars campaigns 2009 to 2016) in the Utah desert and in other extreme environments (Iceland, Eifel, La Reunion) relevant to habitability and astrobiology in Mars environments, and in order to help in the interpretation of Mars missions measurements from orbit (MEX, MRO) or from the surface (MER, MSL). We discuss results relevant to the scientific study of the habitability factors influenced by the properties of dust, organics, water history and the diagnostics and characterisation of microbial life. We also discuss perspectives for the preparation of future lander and sample return missions. We deployed at Mars Desert Research station, Utah, a suite of instruments and techniques including sample collection, context imaging from remote to local and microscale, drilling, spectrometers and life sensors. We analyzed how geological and geochemical evolution affected local parameters (mineralogy, organics content, environment variations) and the habitability and signature of organics and biota. We find high diversity in the composition of soil samples even when collected in close proximity, the low abundances of detectable PAHs and amino acids and the presence of biota of all three domains of life with significant heterogeneity. An extraordinary variety of putative extremophiles was observed. A dominant factor seems to be soil porosity and lower clay-sized particle content. A protocol was developed for sterile sampling, contamination issues, and the diagnostics of biodiversity via PCR and DGGE analysis in soils and rocks samples. We compare campaign results from 2009-2013 campaigns in Utah and other sites to new measurements concerning: the comparison between remote sensing and in-situ measurements; the study of minerals; the detection of organics and signs of life.

  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. Sampling and analysis of phloem sap.

    PubMed

    Dinant, Sylvie; Kehr, Julia

    2013-01-01

    The transport tubes of the phloem are essential for higher plants. They not only provide the route for the distribution of assimilates produced during photosynthesis from source to sink organs but also (re-) distribute mineral nutrients. Additionally, the phloem is essential for sending information between distant plant organs and steering developmental and defense processes. For example, flowering and tuberization time are controlled by phloem-mobile signals and important defense reactions on the whole plant level, like systemic acquired resistance or systemic gene silencing, are spread through the phloem. In addition, recent results demonstrate that also the allocation of mineral nutrients is coordinated by phloem mobile signaling molecules. However, in many studies the important analysis of phloem sap is neglected, probably because the content of sieve tubes is not easy to access. This chapter will describe the current methods for sampling and analysis of phloem sap in order to encourage researchers to include the analysis of this crucial compartment in their relevant studies.

  3. Characterisation of spilled oil samples: Purpose, sampling, analysis and interpretation

    SciTech Connect

    Butt, J.A.; Duckworth, D.F.; Perry, S.G.

    1986-01-01

    An updated version of Marine Pollution by Oil(l974), this book provides recommendations on the forensic analysis of petroleum derived pollutants fojuind in marine environments. It includes the many new methods developed since the first volume was published.

  4. SALI chemical analysis of provided samples

    NASA Technical Reports Server (NTRS)

    Becker, Christopher H.

    1993-01-01

    SRI has completed the chemical analysis of all the samples supplied by NASA. The final batch of four samples consisted of: one inch diameter MgF2 mirror, control 1200-ID-FL3; one inch diameter neat resin, PMR-15, AO171-IV-55, half exposed and half unexposed; one inch diameter chromic acid anodized, EOIM-3 120-47 aluminum disc; and AO-exposed and unexposed samples of fullerene extract material in powdered form, pressed into In foil for analysis. Chemical analyses of the surfaces were performed by the surface analysis by laser ionization (SALI) method. The analyses emphasize surface contamination or general organic composition. SALI uses nonselective photoionization of sputtered or desorbed atoms and molecules above but close (approximately one mm) to the surface, followed by time-of-flight (TOF) mass spectrometry. In these studies, we used laser-induced desorption by 5-ns pulse-width 355-nm light (10-100 mJ/sq cm) and single-photon ionization (SPI) by coherent 118-nm radiation (at approximately 5 x 10(exp 5) W/sq cm). SPI was chosen primarily for its ability to obtain molecular information, whereas multiphoton ionization (not used in the present studies) is intended primarily for elemental and small molecule information. In addition to these four samples, the Au mirror (EOIM-3 200-11, sample four) was depth profiled again. Argon ion sputtering was used together with photoionization with intense 355-nm radiation (35-ps pulsewidths). Depth profiles are similar to those reported earlier, showing reproducibility. No chromium was found in the sample above noise level; its presence could at most be at the trace level. Somewhat more Ni appears to be present in the Au layer in the unexposed side, indicating thermal diffusion without chemical enhancement. The result of the presence of oxygen is apparently to tie-up/draw out the Ni as an oxide at the surface. The exposed region has a brownish tint appearance to the naked eye.

  5. 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.

  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.

    1994-12-31

    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.

  7. 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.

  8. Microextraction sample preparation techniques in biomedical analysis.

    PubMed

    Szultka, Malgorzata; Pomastowski, Pawel; Railean-Plugaru, Viorica; Buszewski, Boguslaw

    2014-11-01

    Biologically active compounds are found in biological samples at relatively low concentration levels. The sample preparation of target compounds from biological, pharmaceutical, environmental, and food matrices is one of the most time-consuming steps in the analytical procedure. The microextraction techniques are dominant. Metabolomic studies also require application of proper analytical technique for the determination of endogenic metabolites present in biological matrix on trace concentration levels. Due to the reproducibility of data, precision, relatively low cost of the appropriate analysis, simplicity of the determination, and the possibility of direct combination of those techniques with other methods (combination types on-line and off-line), they have become the most widespread in routine determinations. Additionally, sample pretreatment procedures have to be more selective, cheap, quick, and environmentally friendly. This review summarizes the current achievements and applications of microextraction techniques. The main aim is to deal with the utilization of different types of sorbents for microextraction and emphasize the use of new synthesized sorbents as well as to bring together studies concerning the systematic approach to method development. This review is dedicated to the description of microextraction techniques and their application in biomedical analysis.

  9. Transuranic waste characterization sampling and analysis plan

    SciTech Connect

    1994-12-31

    Los Alamos National Laboratory (the Laboratory) is located approximately 25 miles northwest of Santa Fe, New Mexico, situated on the Pajarito Plateau. Technical Area 54 (TA-54), one of the Laboratory`s many technical areas, is a radioactive and hazardous waste management and disposal area located within the Laboratory`s boundaries. The purpose of this transuranic waste characterization, sampling, and analysis plan (CSAP) is to provide a methodology for identifying, characterizing, and sampling approximately 25,000 containers of transuranic waste stored at Pads 1, 2, and 4, Dome 48, and the Fiberglass Reinforced Plywood Box Dome at TA-54, Area G, of the Laboratory. Transuranic waste currently stored at Area G was generated primarily from research and development activities, processing and recovery operations, and decontamination and decommissioning projects. This document was created to facilitate compliance with several regulatory requirements and program drivers that are relevant to waste management at the Laboratory, including concerns of the New Mexico Environment Department.

  10. 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

  11. 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.

  12. 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.

  13. 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.

  14. EMP Attachment 1 DOE-SC PNNL Site Sampling and Analysis Plan

    SciTech Connect

    Meier, Kirsten M.

    2011-11-10

    This Sampling and Analysis Plan (SAP) is written for the radiological environmental air surveillance program for the DOE-SC PNNL Site, Richland Washington. It provides the requirements for planning sampling events, and the requirements imposed on the analytical laboratory analyzing the air samples. The actual air sampling process is in procedure EPRP-AIR-029. The rationale for analyte selection, media, and sampling site location has been vetted through the data quality objectives (DQO) process (Barnett et al. 2010). The results from the DQO process have been reviewed and approved by the Washington State Department of Health. The DQO process (Barnett et al. 2010) identified seven specific radionuclides for analysis along with the need for gross alpha and gross beta radiological analyses. The analytes are {sup 241}Am, {sup 243}Am, {sup 244}Cm, {sup 60}Co, {sup 238}Pu, {sup 239}Pu, and {sup 233}U. The report also determined that air samples for particulates are the only sample matrix required for the monitoring program. These samples are collected on 47-mm glass-fiber filters.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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...

  1. 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...

  2. 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…

  3. 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

  4. High priority tank sampling and analysis report

    SciTech Connect

    Brown, T.M.

    1998-03-05

    In July 1993, the Defense Nuclear Facilities Safety Board (DNFSB) transmitted Recommendation 93-5 (Conway 1993) to the US Department of Energy (DOE). Recommendation 93-5 noted that there was insufficient tank waste technical information and the pace to obtain it was too slow to ensure that Hanford Site wastes could be safely stored, that associated operations could be conducted safely, and that future disposal data requirements could be met. In May 1996, the DOE issued Revision 1 of the Recommendation 93-5 Implementation Plan (DOE-RL 1996). The Implementation Plan revision presented a modified approach to achieve the original plan`s objectives. The approach concentrated on actions necessary to ensure that wastes can be safely stored, that operations can be safely conducted, and that timely characterization information for the tank waste Disposal Program could be obtained. The Implementation Plan proposed 28 High Priority tanks, which, if sampled and analyzed, were expected to provide information to answer questions regarding safety and disposal issues. The High Priority tank list was originally developed in Section 9.0 of the Tank Waste Characterization Basis (Brown et al. 1995) by integrating the needs of the various safety and disposal programs. The High Priority tank list represents a set of tanks that were expected to provide the highest information return for characterization resources expended. The High Priority tanks were selected for near-term core sampling and were not expected to be the only tanks that would provide meaningful information. Sampling and analysis of non-High Priority tanks also could be used to provide scientific and technical data to confirm assumptions, calibrate models, and measure safety related phenomenological characteristics of the waste. When the sampling and analysis results of the High Priority and other tanks were reviewed, it was expected that a series of questions should be answered allowing key decisions to be made. The first

  5. 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.

  6. 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

  7. 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.

  8. 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.

  9. 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.

  10. (ISEA) MOLECULAR MARKER ANALYSIS OF DEARS SAMPLES

    EPA Science Inventory

    Source apportionment based on organic molecular markers provides a promising approach for meeting the Detroit Exposure and Aerosol Research Study (DEARS) objective of comparing source contributions between community air monitoring stations and various neighborhoods. Source appor...

  11. MOLECULAR MARKER ANALYSIS OF DEARS SAMPLES

    EPA Science Inventory

    Source apportionment based on organic molecular markers provides a promising approach for meeting the Detroit Exposure and Aerosol Research Study (DEARS) objective of comparing source contributions between community air monitoring stations and various neighborhoods. Source appor...

  12. 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

  13. 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.

  14. Analysis of Returned Comet Nucleus Samples

    NASA Astrophysics Data System (ADS)

    Chang, Sherwood

    1997-12-01

    This volume contains abstracts that have been accepted by the Program Committee for presentation at the Workshop on Analysis of Returned Comet Nucleus Samples, held in Milpitas, California, January 16-18, 1989. Conveners are Sherwood Chang (NASA Ames Research Center) and Larry Nyquist (NASA Johnson Space Center). Program Committee members are Thomas Ahrens (ex-officio; California Institute of Technology), Lou Allamandola (NASA Ames Research Center), David Blake (NASA Ames Research Center), Donald Brownlee (University of Washington, Seattle), Theodore E. Bunch (NASA Ames Research Center), Humberto Campins (Planetary Science Institute), Jeff Cuzzi (NASA Ames Research Center), Eberhard Griin (Max-Plank-Institut fiir Kemphysik), Martha Hanner (Jet Propulsion Laboratory), Alan Harris (Jet Propulsion Laboratory), John Kerrid-e (University of Califomia, Los Angeles), Yves Langevin (University of Paris), Gerhard Schwehm (ESTEC), and Paul Weissman (Jet Propulsion Laboratory). Logistics and administrative support for the workshop were provided by the Lunar and Planetary Institute Projects Office.

  15. Analysis of Returned Comet Nucleus Samples

    NASA Technical Reports Server (NTRS)

    Chang, Sherwood (Compiler)

    1997-01-01

    This volume contains abstracts that have been accepted by the Program Committee for presentation at the Workshop on Analysis of Returned Comet Nucleus Samples, held in Milpitas, California, January 16-18, 1989. Conveners are Sherwood Chang (NASA Ames Research Center) and Larry Nyquist (NASA Johnson Space Center). Program Committee members are Thomas Ahrens (ex-officio; California Institute of Technology), Lou Allamandola (NASA Ames Research Center), David Blake (NASA Ames Research Center), Donald Brownlee (University of Washington, Seattle), Theodore E. Bunch (NASA Ames Research Center), Humberto Campins (Planetary Science Institute), Jeff Cuzzi (NASA Ames Research Center), Eberhard Griin (Max-Plank-Institut fiir Kemphysik), Martha Hanner (Jet Propulsion Laboratory), Alan Harris (Jet Propulsion Laboratory), John Kerrid-e (University of Califomia, Los Angeles), Yves Langevin (University of Paris), Gerhard Schwehm (ESTEC), and Paul Weissman (Jet Propulsion Laboratory). Logistics and administrative support for the workshop were provided by the Lunar and Planetary Institute Projects Office.

  16. 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%.

  17. 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

  18. Business Case Analysis of the Special Operations Air Mobility Vehicle

    DTIC Science & Technology

    2013-12-01

    NAVAL POSTGRADUATE SCHOOL MONTEREY, CALIFORNIA MBA PROFESSIONAL REPORT BUSINESS CASE ANALYSIS OF THE SPECIAL OPERATIONS AIR...2013 3. REPORT TYPE AND DATES COVERED MBA Professional Report 4. TITLE AND SUBTITLE BUSINESS CASE ANALYSIS OF THE SPECIAL OPERATIONS AIR...perform an industry analysis of the WSC training and aircraft sales industry; and (3) determine the expected government training capabilities and costs

  19. 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.

  20. Sample Analysis at Mars Instrument Simulator

    NASA Technical Reports Server (NTRS)

    Benna, Mehdi; Nolan, Tom

    2013-01-01

    The Sample Analysis at Mars Instrument Simulator (SAMSIM) is a numerical model dedicated to plan and validate operations of the Sample Analysis at Mars (SAM) instrument on the surface of Mars. The SAM instrument suite, currently operating on the Mars Science Laboratory (MSL), is an analytical laboratory designed to investigate the chemical and isotopic composition of the atmosphere and volatiles extracted from solid samples. SAMSIM was developed using Matlab and Simulink libraries of MathWorks Inc. to provide MSL mission planners with accurate predictions of the instrument electrical, thermal, mechanical, and fluid responses to scripted commands. This tool is a first example of a multi-purpose, full-scale numerical modeling of a flight instrument with the purpose of supplementing or even eliminating entirely the need for a hardware engineer model during instrument development and operation. SAMSIM simulates the complex interactions that occur between the instrument Command and Data Handling unit (C&DH) and all subsystems during the execution of experiment sequences. A typical SAM experiment takes many hours to complete and involves hundreds of components. During the simulation, the electrical, mechanical, thermal, and gas dynamics states of each hardware component are accurately modeled and propagated within the simulation environment at faster than real time. This allows the simulation, in just a few minutes, of experiment sequences that takes many hours to execute on the real instrument. The SAMSIM model is divided into five distinct but interacting modules: software, mechanical, thermal, gas flow, and electrical modules. The software module simulates the instrument C&DH by executing a customized version of the instrument flight software in a Matlab environment. The inputs and outputs to this synthetic C&DH are mapped to virtual sensors and command lines that mimic in their structure and connectivity the layout of the instrument harnesses. This module executes

  1. Preparation of urine samples for proteomic analysis.

    PubMed

    Pieper, Rembert

    2008-01-01

    Reproducible procedures for the preparation of protein samples isolated from human urine are essential for meaningful proteomic analyses. Key applications are the discovery of novel proteins or their modifications in the human urine as well as protein biomarker discovery for diseases and drug treatments. The methodology presented here features experimental steps aimed at limiting protein losses because of organic solvent precipitation, effective separation of proteins from other compounds in the human urine and molecular weight-based enrichment of proteins in two distinct fractions. Urinary proteins are separated from cellular debris in the urine via centrifugation, concentrated with 5-kDa-cutoff membrane concentration devices and separated via size exclusion chromatography into fractions with a higher and a lower molecular weight than 30 kDa, respectively. A successive optional affinity removal step for highly abundant plasma proteins is described. Finally, buffer exchange steps useful for specific downstream proteomic analysis experiments of urinary proteins are presented, such as 2-dimensional gel electrophoresis, differential protein or peptide labeling and digestion with trypsin for LC-MS/MS analysis.

  2. Organically bound tritium analysis in environmental samples

    SciTech Connect

    Baglan, N.; Cossonnet, C.; Fournier, M.; Momoshima, N.; Ansoborlo, E.

    2015-03-15

    Organically bound tritium (OBT) has become of increased interest within the last decade, with a focus on its behaviour and also its analysis, which are important to assess tritium distribution in the environment. In contrast, there are no certified reference materials and no standard analytical method through the international organization related to OBT. In order to resolve this issue, an OBT international working group was created in May 2012. Over 20 labs from around the world participated and submitted their results for the first intercomparison exercise results on potato (Sep 2013). The samples, specially-prepared potatoes, were provided in March 2013 to each participant. Technical information and results from this first exercise are discussed here for all the labs which have realised the five replicates necessary to allow a reliable statistical treatment. The results are encouraging as the increased number of participating labs did not degrade the observed dispersion of the results for a similar activity level. Therefore, the results do not seem to depend on the analytical procedure used. From this work an optimised procedure can start to be developed to deal with OBT analysis and will guide subsequent planned OBT trials by the international group.

  3. 40 CFR 761.292 - Chemical extraction and analysis of individual samples and composite samples.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... individual samples and composite samples. 761.292 Section 761.292 Protection of Environment ENVIRONMENTAL....61(a)(6) § 761.292 Chemical extraction and analysis of individual samples and composite samples. Use... individual and composite samples of PCB remediation waste. Use Method 8082 from SW-846, or a method...

  4. 40 CFR 761.292 - Chemical extraction and analysis of individual samples and composite samples.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... individual samples and composite samples. 761.292 Section 761.292 Protection of Environment ENVIRONMENTAL....61(a)(6) § 761.292 Chemical extraction and analysis of individual samples and composite samples. Use... individual and composite samples of PCB remediation waste. Use Method 8082 from SW-846, or a method...

  5. 40 CFR 761.292 - Chemical extraction and analysis of individual samples and composite samples.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... individual samples and composite samples. 761.292 Section 761.292 Protection of Environment ENVIRONMENTAL....61(a)(6) § 761.292 Chemical extraction and analysis of individual samples and composite samples. Use... individual and composite samples of PCB remediation waste. Use Method 8082 from SW-846, or a method...

  6. Europlanet Research Infrastructure: Planetary Sample Analysis Facilities

    NASA Astrophysics Data System (ADS)

    Cloquet, C.; Mason, N. J.; Davies, G. R.; Marty, B.

    2008-09-01

    EuroPlanet The Europlanet Research Infrastructure consortium funded under FP7 aims to provide the EU Planetary Science community greater access for to research infrastructure. A series of networking and outreach initiatives will be complimented by joint research activities and the formation of three Trans National Access distributed service laboratories (TNA's) to provide a unique and comprehensive set of analogue field sites, laboratory simulation facilities, and extraterrestrial sample analysis tools. Here we report on the infrastructure that comprises the third TNA: Planetary Sample Analysis Facilities. The modular infrastructure represents a major commitment of analytical instrumentation by three institutes and together forms a state-of-the-art analytical facility of unprecedented breadth. These centres perform research in the fields of geochemistry and cosmochemistry, studying fluids and rocks in order to better understand the keys cof the universe. Europlanet Research Infrastructure Facilities: Ion Probe facilities at CRPG and OU The Cameca 1270 Ion microprobe is a CNRS-INSU national facility. About a third of the useful analytical time of the ion probe (about 3 months each year) is allocated to the national community. French scientists have to submit their projects to a national committee for selection. The selected projects are allocated time in the following 6 months twice a year. About 15 to 20 projects are run each year. There are only two such instruments in Europe, with cosmochemistry only performed at CRPG. Different analyses can be performed on a routine basis, such as U-Pb dating on Zircon, Monazite or Pechblende, Li, B, C, O, Si isotopic ratios determination on different matrix, 26Al, 60Fe extinct radioactivity ages, light and trace elements contents . The NanoSIMS 50L - producing element or isotope maps with a spatial resolution down to ≈50nm. This is one of the cornerstone facilities of UKCAN, with 75% of available instrument time funded and

  7. The beryllium quandary: will the lower exposure limits spur new developments in sampling and analysis?

    SciTech Connect

    Brisson, Michael

    2013-06-03

    At the time this article was written, new rulemakings were under consideration at OSHA and the U.S. Department of Energy (DOE) that would propose changes to occupational exposure limits for beryllium. Given these developments, it’s a good time to review the tools and methods available to IHs for assessing beryllium air and surface contamination in the workplace—what’s new and different, and what’s tried and true. The article discusses limit values and action levels for beryllium, problematic aspects of beryllium air sampling, sample preparation, sample analysis, and data evaluation.

  8. Interlaboratory analysis of high molecular weight organochlorines in ambient air

    NASA Astrophysics Data System (ADS)

    Bidleman, Terry F.

    High volume air samples were collected in Boston, MA, and Columbia, SC using a glass fiber filter — polyurethane foam trap, and the pooled sample extracts from each location were distributed among nine laboratories for organochlorine analysis. Polychlorinated biphenyls (PCB) were reported by all laboratories, with relative standard deviations (RSDs) ranging from 26-39 % for total PCB. The total PCB concentration in Boston was 7.1 ng m -3, compared to 4.4 ng m -3 in Columbia. Other organochlorines identified by three or more laboratories included hexachlorobenzene and the pesticides DDT, DDE, chlordane, dieldrin, endrin, hexachlorocyclohexane, and polychloroterpenes. RSDs for most pesticides ranged from 35-75% and as high as 116% for polychloroterpenes (quantified as toxaphene). In general, pesticide levels were an order of magnitude higher in Columbia than in Boston.

  9. Sampling and analysis of natural gas trace constituents

    SciTech Connect

    Attari, A.; Chao, S.

    1993-09-01

    Major and minor components of natural gas are routinely analyzed by gas chromatography (GC), using a thermal conductivity (TC). The best results obtained by these methods can report no better than 0.01 mole percent of each measured component. Even the extended method of analysis by flame ionization detector (FID) can only improve on the detection limit of hydrocarbons. The gas industry needs better information on all trace constituents of natural gas, whether native or inadvertently added during gas processing that may adversely influence the operation of equipment or the safety of the consumer. The presence of arsenic and mercury in some gas deposits have now been documented in international literature as causing not only human toxicity but also damaging to the field equipment. Yet, no standard methods of sampling and analysis exist to provide this much needed information. In this paper the authors report the results of a three-year program to develop an extensive array of sampling and analysis methods for speciation and measurement of trace constituents of natural gas. A cryogenic sampler operating at near 200 K ({minus}99 F) and at pipeline pressures up to 12.4 {times} 10{sup 6}Pa (1800 psig) has been developed to preconcentrate and recover all trace constituents with boiling points above butanes. Specific analytical methods have been developed for speciating and measurement of many trace components (corresponding to US EPA air toxics) by GC-AED and GC-MS, and for determining various target compounds by other techniques. Moisture, oxygen and sulfur contents are measured on site using dedicated field instruments. Arsenic, mercury and radon are sampled by specific solid sorbents for subsequent laboratory analysis.

  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. Report of Sampling and Analysis Results: Swansea Army Housing Units, Swansea, Massachusetts

    DTIC Science & Technology

    1990-08-01

    recommended to determine if the asbestos is becoming airborne and to define what risks, if3 any , are presented by these findings. These studies were...inspection of the floor coverings and the3 removal and replacement of any that become damaged. Other suspect materials identified but not sampled...a dust sample was collected from this vent and analyzed. The air samples were subjected to analysis by TEM to identify and quantify any asbestos

  12. Using Inverse Probability Bootstrap Sampling to Eliminate Sample Induced Bias in Model Based Analysis of Unequal Probability Samples.

    PubMed

    Nahorniak, Matthew; Larsen, David P; Volk, Carol; Jordan, Chris E

    2015-01-01

    In ecology, as in other research fields, efficient sampling for population estimation often drives sample designs toward unequal probability sampling, such as in stratified sampling. Design based statistical analysis tools are appropriate for seamless integration of sample design into the statistical analysis. However, it is also common and necessary, after a sampling design has been implemented, to use datasets to address questions that, in many cases, were not considered during the sampling design phase. Questions may arise requiring the use of model based statistical tools such as multiple regression, quantile regression, or regression tree analysis. However, such model based tools may require, for ensuring unbiased estimation, data from simple random samples, which can be problematic when analyzing data from unequal probability designs. Despite numerous method specific tools available to properly account for sampling design, too often in the analysis of ecological data, sample design is ignored and consequences are not properly considered. We demonstrate here that violation of this assumption can lead to biased parameter estimates in ecological research. In addition, to the set of tools available for researchers to properly account for sampling design in model based analysis, we introduce inverse probability bootstrapping (IPB). Inverse probability bootstrapping is an easily implemented method for obtaining equal probability re-samples from a probability sample, from which unbiased model based estimates can be made. We demonstrate the potential for bias in model-based analyses that ignore sample inclusion probabilities, and the effectiveness of IPB sampling in eliminating this bias, using both simulated and actual ecological data. For illustration, we considered three model based analysis tools--linear regression, quantile regression, and boosted regression tree analysis. In all models, using both simulated and actual ecological data, we found inferences to be

  13. Using Inverse Probability Bootstrap Sampling to Eliminate Sample Induced Bias in Model Based Analysis of Unequal Probability Samples

    PubMed Central

    Nahorniak, Matthew

    2015-01-01

    In ecology, as in other research fields, efficient sampling for population estimation often drives sample designs toward unequal probability sampling, such as in stratified sampling. Design based statistical analysis tools are appropriate for seamless integration of sample design into the statistical analysis. However, it is also common and necessary, after a sampling design has been implemented, to use datasets to address questions that, in many cases, were not considered during the sampling design phase. Questions may arise requiring the use of model based statistical tools such as multiple regression, quantile regression, or regression tree analysis. However, such model based tools may require, for ensuring unbiased estimation, data from simple random samples, which can be problematic when analyzing data from unequal probability designs. Despite numerous method specific tools available to properly account for sampling design, too often in the analysis of ecological data, sample design is ignored and consequences are not properly considered. We demonstrate here that violation of this assumption can lead to biased parameter estimates in ecological research. In addition, to the set of tools available for researchers to properly account for sampling design in model based analysis, we introduce inverse probability bootstrapping (IPB). Inverse probability bootstrapping is an easily implemented method for obtaining equal probability re-samples from a probability sample, from which unbiased model based estimates can be made. We demonstrate the potential for bias in model-based analyses that ignore sample inclusion probabilities, and the effectiveness of IPB sampling in eliminating this bias, using both simulated and actual ecological data. For illustration, we considered three model based analysis tools—linear regression, quantile regression, and boosted regression tree analysis. In all models, using both simulated and actual ecological data, we found inferences to be

  14. 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.

  15. 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

  16. 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

  17. 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.

  18. 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.

  19. 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

  20. 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.

  1. Spacelab J air filter debris analysis

    NASA Technical Reports Server (NTRS)

    Obenhuber, Donald C.

    1993-01-01

    Filter debris from the Spacelab module SLJ of STS-49 was analyzed for microbial contamination. Debris for cabin and avionics filters was collected by Kennedy Space Center personnel on 1 Oct. 1992, approximately 5 days postflight. The concentration of microorganisms found was similar to previous Spacelab missions averaging 7.4E+4 CFU/mL for avionics filter debris and 4.5E+6 CFU/mL for the cabin filter debris. A similar diversity of bacterial types was found in the two filters. Of the 13 different bacterial types identified from the cabin and avionics samples, 6 were common to both filters. The overall analysis of these samples as compared to those of previous missions shows no significant differences.

  2. 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.

  3. 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 ...

  4. 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

  5. Tank 241-TY-103 rotary core sampling and analysis

    SciTech Connect

    Jo, J.

    1995-10-30

    This Sampling and Analysis Plan (SAP) identifies characterization objectives pertaining to sample collection, laboratory analytical evaluation, and reporting requirements for two rotary-mode core samples from tank 241-TY-103

  6. Sampling and analysis plan for canister liquid and gas sampling at 105 KW fuel storage basin

    SciTech Connect

    Trimble, D.J.

    1996-08-09

    This Sampling and Analysis Plan describes the equipment,procedures and techniques for obtaining gas and liquid samples from sealed K West fuel canisters. The analytical procedures and quality assurance requirements for the subsequent laboratory analysis of the samples are also discussed.

  7. 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.

  8. Techniques for geothermal liquid sampling and analysis

    SciTech Connect

    Kindle, C.H.; Woodruff, E.M.

    1981-07-01

    A methodology has been developed that is particularly suited to liquid-dominated resources and adaptable to a variety of situations. It is intended to be a base methodology upon which variations can be made to meet specific needs or situations. The approach consists of recording flow conditions at the time of sampling, a specific insertable probe sampling system, a sample stabilization procedure, commercially available laboratory instruments, and data quality check procedures.

  9. Air Cargo Transportation Route Choice Analysis

    NASA Technical Reports Server (NTRS)

    Obashi, Hiroshi; Kim, Tae-Seung; Oum, Tae Hoon

    2003-01-01

    Using a unique feature of air cargo transshipment data in the Northeast Asian region, this paper identifies the critical factors that determine the transshipment route choice. Taking advantage of the variations in the transport characteristics in each origin-destination airports pair, the paper uses a discrete choice model to describe the transshipping route choice decision made by an agent (i.e., freight forwarder, consolidator, and large shipper). The analysis incorporates two major factors, monetary cost (such as line-haul cost and landing fee) and time cost (i.e., aircraft turnaround time, including loading and unloading time, custom clearance time, and expected scheduled delay), along with other controls. The estimation method considers the presence of unobserved attributes, and corrects for resulting endogeneity by use of appropriate instrumental variables. Estimation results find that transshipment volumes are more sensitive to time cost, and that the reduction in aircraft turnaround time by 1 hour would be worth the increase in airport charges by more than $1000. Simulation exercises measures the impacts of alternative policy scenarios for a Korean airport, which has recently declared their intention to be a future regional hub in the Northeast Asian region. The results suggest that reducing aircraft turnaround time at the airport be an effective strategy, rather than subsidizing to reduce airport charges.

  10. Prompt Gamma Ray Analysis of Soil Samples

    SciTech Connect

    Naqvi, A.A.; Khiari, F.Z.; Haseeb, S.M.A.; Hussein, Tanvir; Khateeb-ur-Rehman; Isab, A.H.

    2015-07-01

    Neutron moderation effects were measured in bulk soil samples through prompt gamma ray measurements from water and benzene contaminated soil samples using 14 MeV neutron inelastic scattering. The prompt gamma rays were measured using a cylindrical 76 mm x 76 mm (diameter x height) LaBr{sub 3}:Ce detector. Since neutron moderation effects strongly depend upon hydrogen concentration of the sample, for comparison purposes, moderation effects were studied from samples containing different hydrogen concentrations. The soil samples with different hydrogen concentration were prepared by mixing soil with water as well as benzene in different weight proportions. Then, the effects of increasing water and benzene concentrations on the yields of hydrogen, carbon and silicon prompt gamma rays were measured. Moderation effects are more pronounced in soil samples mixed with water as compared to those from soil samples mixed with benzene. This is due to the fact that benzene contaminated soil samples have about 30% less hydrogen concentration by weight than the water contaminated soil samples. Results of the study will be presented. (authors)

  11. Colling Wipe Samples for VX Analysis

    SciTech Connect

    Koester, C; Hoppes, W G

    2010-02-11

    This standard operating procedure (SOP) provides uniform procedures for the collection of wipe samples of VX residues from surfaces. Personnel may use this procedure to collect and handle wipe samples in the field. Various surfaces, including building materials (wood, metal, tile, vinyl, etc.) and equipment, may be sampled based on this procedure. The purpose of such sampling is to determine whether or not the relevant surfaces are contaminated, to determine the extent of their contamination, to evaluate the effectiveness of decontamination procedures, and to determine the amount of contaminant that might present as a contact hazard.

  12. 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.

  13. Incorporating principal component analysis into air quality model evaluation

    NASA Astrophysics Data System (ADS)

    Eder, Brian; Bash, Jesse; Foley, Kristen; Pleim, Jon

    2014-01-01

    The efficacy of standard air quality model evaluation techniques is becoming compromised as the simulation periods continue to lengthen in response to ever increasing computing capacity. Accordingly, the purpose of this paper is to demonstrate a statistical approach called Principal Component Analysis (PCA) with the intent of motivating its use by the evaluation community. One of the main objectives of PCA is to identify, through data reduction, the recurring and independent modes of variations (or signals) within a very large dataset, thereby summarizing the essential information of that dataset so that meaningful and descriptive conclusions can be made. In this demonstration, PCA is applied to a simple evaluation metric - the model bias associated with EPA's Community Multi-scale Air Quality (CMAQ) model when compared to weekly observations of sulfate (SO42-) and ammonium (NH4+) ambient air concentrations measured by the Clean Air Status and Trends Network (CASTNet). The advantages of using this technique are demonstrated as it identifies strong and systematic patterns of CMAQ model bias across a myriad of spatial and temporal scales that are neither constrained to geopolitical boundaries nor monthly/seasonal time periods (a limitation of many current studies). The technique also identifies locations (station-grid cell pairs) that are used as indicators for a more thorough diagnostic evaluation thereby hastening and facilitating understanding of the probable mechanisms responsible for the unique behavior among bias regimes. A sampling of results indicates that biases are still prevalent in both SO42- and NH4+ simulations that can be attributed to either: 1) cloud processes in the meteorological model utilized by CMAQ, which are found to overestimated convective clouds and precipitation, while underestimating larger-scale resolved clouds that are less likely to precipitate, and 2) biases associated with Midwest NH3 emissions which may be partially ameliorated

  14. Analysis of Aircraft Evasion Strategies in Air-to-Air Missille Effectiveness Models

    DTIC Science & Technology

    1975-08-01

    AD-A015 238 ANALYSIS OF AIRCRAFT EVASION STRATEGIES IN AIR-TO-AIR MISSILE EFFECTIVENESS MObri ’ G. Carpenter, et al Grumman Aerospace Corporation ...overall tep t Es CIS*atiet d) Oft ’IsNA 1tTNG AC ?v I TV ? corpor te author) 2S. REPORT SECUNITY CLASSIrICA TION Unclassified ;rummn Aerospace... Corporation b RoU N/A I NEPOA’ I ?LE nalysis of Aircraft Evasion Strategies in Air-to-Air Missile Effectiveness Models 4 DESCRIP T IVE *40TS ’Type of repct

  15. A comparison of portable XRF and ICP-OES analysis for lead on air filter samples from a lead ore concentrator mill and a lead-acid battery recycler.

    PubMed

    Harper, Martin; Pacolay, Bruce; Hintz, Patrick; Andrew, Michael E

    2006-03-01

    Personal and area samples for airborne lead were taken at a lead mine concentrator mill, and at a lead-acid battery recycler. Lead is mined as its sulfidic ore, galena, which is often associated with zinc and silver. The ore typically is concentrated, and partially separated, on site by crushing and differential froth flotation of the ore minerals before being sent to a primary smelter. Besides lead, zinc and iron are also present in the airborne dusts, together with insignificant levels of copper and silver, and, in one area, manganese. The disposal of used lead-acid batteries presents environmental issues, and is also a waste of recoverable materials. Recycling operations allow for the recovery of lead, which can then be sold back to battery manufacturers to form a closed loop. At the recycling facility lead is the chief airborne metal, together with minor antimony and tin, but several other metals are generally present in much smaller quantities, including copper, chromium, manganese and cadmium. Samplers used in these studies included the closed-face 37 mm filter cassette (the current US standard method for lead sampling), the 37 mm GSP or "cone" sampler, the 25 mm Institute of Occupational Medicine (IOM) inhalable sampler, the 25 mm Button sampler, and the open-face 25 mm cassette. Mixed cellulose-ester filters were used in all samplers. The filters were analyzed after sampling for their content of the various metals, particularly lead, that could be analyzed by the specific portable X-ray fluorescence (XRF) analyzer under study, and then were extracted with acid and analyzed by inductively coupled plasma optical emission spectroscopy (ICP-OES). The 25 mm filters were analyzed using a single XRF reading, while three readings on different parts of the filter were taken from the 37 mm filters. For lead at the mine concentrate mill, all five samplers gave good correlations (r2 > 0.96) between the two analytical methods over the entire range of found lead mass

  16. 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.

  17. 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.

  18. Space X First Entry Sample Analysis

    NASA Technical Reports Server (NTRS)

    James, John T.

    2012-01-01

    The toxicological assessment of one sample collected on May 26, 2012 and returned to earth on May 31, 2012 was analyzed for pollutants that had offgassed into the Dragon capsule by the time of first entry operations performed by the ISS crew. The components identified in the first-entry sample and their contributions to the total T-value are shown.

  19. 7 CFR 58.245 - Method of sample analysis.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 3 2013-01-01 2013-01-01 false Method of sample analysis. 58.245 Section 58.245... Procedures § 58.245 Method of sample analysis. Samples shall be tested according to the applicable methods of laboratory analysis contained in either DA Instruction 918-RL as issued by the USDA, Agricultural...

  20. 7 CFR 58.812 - Methods of sample analysis.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 3 2013-01-01 2013-01-01 false Methods of sample analysis. 58.812 Section 58.812... Procedures § 58.812 Methods of sample analysis. Samples shall be tested according to the applicable methods of laboratory analysis contained in either DA Instruction 918-RL, as issued by the USDA,...

  1. 7 CFR 58.812 - Methods of sample analysis.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Methods of sample analysis. 58.812 Section 58.812... Procedures § 58.812 Methods of sample analysis. Samples shall be tested according to the applicable methods of laboratory analysis contained in either DA Instruction 918-RL, as issued by the USDA,...

  2. 7 CFR 58.245 - Method of sample analysis.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Method of sample analysis. 58.245 Section 58.245... Procedures § 58.245 Method of sample analysis. Samples shall be tested according to the applicable methods of laboratory analysis contained in either DA Instruction 918-RL as issued by the USDA, Agricultural...

  3. HIGH VOLUME INJECTION FOR GCMS ANALYSIS OF PARTICULATE ORGANIC SPECIES IN AMBIENT AIR

    EPA Science Inventory

    Detection of organic species in ambient particulate matter typically requires large air sample volumes, frequently achieved by grouping samples into monthly composites. Decreasing the volume of air sample required would allow shorter collection times and more convenient sample c...

  4. Developments in Sampling and Analysis Instrumentation for Stationary Sources

    ERIC Educational Resources Information Center

    Nader, John S.

    1973-01-01

    Instrumentation for the measurement of pollutant emissions is considered including sample-site selection, sample transport, sample treatment, sample analysis, and data reduction, display, and interpretation. Measurement approaches discussed involve sample extraction from within the stack and electro-optical methods. (BL)

  5. 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.

  6. Failure-cause analysis: Air preheaters

    NASA Astrophysics Data System (ADS)

    Maloney, K. L.; Benson, R. C.

    1981-07-01

    The major generic equipment and/or operating problems responsible for utility power plant outages are examined. Data analyzed from 118 generating units with an average size over 500 MW and using 236 air heaters demonstrates problems with air preheater systems and their components that contribute to loss in performance and unavailability of generating units. Nine major problem areas are identified: corrosion, fouling, plugging, soot blowers, water wash system, seals, fires, and drive and bearing systems. The indicated causes and effects are discussed. Recommendations are made to improve the reliability of existing air preheaters, and generic problems requiring future research and application of existing technologies are identified.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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

  12. 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.

  13. Lab Analysis of Dust Wipe Samples

    EPA Pesticide Factsheets

    Dust wipe samples collected on residential properties near the fenceline of KCBX North and South Terminals in Chicago, which store and handle pet coke, were analyzed for polycyclic aromatic hydrocarbons (PAHs) and trace metals and minerals.

  14. LABORATORY GUIDELINES FOR ANALYSIS OF BIOTERRORISM SAMPLES

    EPA Science Inventory

    With advent of deaths associated with Bacillus anthracis spore contaminated mail, a worldwide need was apparent for increased laboratory capacity to safely analyze bioterrorism samples. The U.S. Department of Health and Human Services has furnished guidelines for microbiological...

  15. WRAP Module 1 sampling and analysis plan

    SciTech Connect

    Mayancsik, B.A.

    1995-03-24

    This document provides the methodology to sample, screen, and analyze waste generated, processed, or otherwise the responsibility of the Waste Receiving and Processing Module 1 facility. This includes Low-Level Waste, Transuranic Waste, Mixed Waste, and Dangerous Waste.

  16. POTW Sludge Sampling and Analysis Guidance Document

    EPA Pesticide Factsheets

    In view of the variability of municipal sludge quality,appropriate procedures must be followed to collect and analyze samples that accurately represent each POTW's sludge quality.This manual was developed to provide that guidance to POTW operators, engin

  17. 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.

  18. 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.

  19. [Variance estimation considering multistage sampling design in multistage complex sample analysis].

    PubMed

    Li, Yichong; Zhao, Yinjun; Wang, Limin; Zhang, Mei; Zhou, Maigeng

    2016-03-01

    Multistage sampling is a frequently-used method in random sampling survey in public health. Clustering or independence between observations often exists in the sampling, often called complex sample, generated by multistage sampling. Sampling error may be underestimated and the probability of type I error may be increased if the multistage sample design was not taken into consideration in analysis. As variance (error) estimator in complex sample is often complicated, statistical software usually adopt ultimate cluster variance estimate (UCVE) to approximate the estimation, which simply assume that the sample comes from one-stage sampling. However, with increased sampling fraction of primary sampling unit, contribution from subsequent sampling stages is no more trivial, and the ultimate cluster variance estimate may, therefore, lead to invalid variance estimation. This paper summarize a method of variance estimation considering multistage sampling design. The performances are compared with UCVE and the method considering multistage sampling design by simulating random sampling under different sampling schemes using real world data. Simulation showed that as primary sampling unit (PSU) sampling fraction increased, UCVE tended to generate increasingly biased estimation, whereas accurate estimates were obtained by using the method considering multistage sampling design.

  20. Analysis of air pollution and greenhouse gases

    SciTech Connect

    Benkovitz, C.M.

    1992-03-01

    The current objective of the project Analysis of Air Pollution and Greenhouse Gases'' is to develop a study of emissions and emission sources that could easily be linked to models of economic activity. Initial studies were conducted to evaluate data currently available linking activity rates and emissions estimates. The emissions inventory developed for the National Acid Precipitation Assessment Program (NAPAP) presents one of the most comprehensive data sets, and was chosen for our initial studies, which are described in this report. Over 99% of the SO{sub 2} emissions, 98% of the NO{sub x} emission and 57% of the VOC emissions from area sources are related to fuel combustion. The majority of emission from these sources are generated by the transportation sector. Activity rates for area sources are not archived with the NAPAP inventory; alternative derivations of these data will be part of the future activities of this project. The availability and completeness of the fuel heat content data in the NAPAP inventory were also studied. Approximately 10% of the SO{sub 2} emissions, 13% of the NO{sub x} emissions and 46% of the VOC emissions are generated by sources with unavailable data for fuel heat content. Initial estimates of pollutant emission rate per unit fuel heat content. Initial estimates of pollutant emission rate per unit fuel heat content were generated. Future studies for this project include the derivation of activity rates for area sources, improved explanations for the default fuel parameters defined in the NAPAP inventory and the development of links to data bases of economic activity.

  1. 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

  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. COMPOSITE SAMPLING FOR SOIL VOC ANALYSIS

    EPA Science Inventory

    Data published by numerous researchers over the last decade demonstrate that there is a high degree of spatial variability in the measurement of volatile organic compounds (VOCs) in soil at contaminated waste sites. This phenomenon is confounded by the use of a small sample aliqu...

  5. Trace Element Analysis of Biological Samples.

    ERIC Educational Resources Information Center

    Veillon, Claude

    1986-01-01

    Reviews background of atomic absorption spectrometry techniques. Discusses problems encountered and precautions to be taken in determining trace elements in the parts-per-billion concentration range and below. Concentrates on determining chromium in biological samples by graphite furnace atomic absorption. Considers other elements, matrices, and…

  6. LABORATORY GUIDELINES FOR ANALYSIS OF BIOTERRORISM SAMPLES

    EPA Science Inventory

    After the attack on the World Trade Center on September 11, 2002, and the subsequent deaths associated with Bacillus anthracis spore contaminated mail, a worldwide need was apparent for increased laboratory capacity to safely analyze bioterrorism samples. The U.S. Department o...

  7. Analysis of large soil samples for actinides

    DOEpatents

    Maxwell, III; Sherrod L.

    2009-03-24

    A method of analyzing relatively large soil samples for actinides by employing a separation process that includes cerium fluoride precipitation for removing the soil matrix and precipitates plutonium, americium, and curium with cerium and hydrofluoric acid followed by separating these actinides using chromatography cartridges.

  8. 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.

  9. 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.

  10. 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.

  11. UMTRA water sampling and analysis plan, Tuba City, Arizona. Draft

    SciTech Connect

    Not Available

    1993-09-01

    The purpose of this document is to provide background, guidance, and justification for fiscal year (FY) 1994 water sampling activities for the uranium mil tailings site at Tuba City, Arizona. This sampling and analysis plan will form the basis for groundwater sampling and analysis work orders to be implemented in FY94.

  12. 27 CFR 26.192 - Samples and analysis.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Samples and analysis. 26.192 Section 26.192 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU... Samples and analysis. The chemist of the Treasury of Puerto Rico may take samples of the product to...

  13. 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.

  14. 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.

  15. Ozone data and mission sampling analysis

    NASA Technical Reports Server (NTRS)

    Robbins, J. L.

    1980-01-01

    A methodology was developed to analyze discrete data obtained from the global distribution of ozone. Statistical analysis techniques were applied to describe the distribution of data variance in terms of empirical orthogonal functions and components of spherical harmonic models. The effects of uneven data distribution and missing data were considered. Data fill based on the autocorrelation structure of the data is described. Computer coding of the analysis techniques is included.

  16. 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

  17. 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.

  18. 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

  19. UMTRA water sampling and analysis plan, Green River, Utah

    SciTech Connect

    Papusch, R.

    1993-12-01

    The purpose of this water sampling and analysis plan (WSAP) is to provide a basis for groundwater and surface water sampling at the Green River Uranium Mill Tailing Remedial Action (UMTRA) Project site. This WSAP identifies and justifies the sampling locations, analytical parameters, detection limits, and sampling frequency for the monitoring locations.

  20. 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.

  1. Waste minimization in environmental sampling and analysis

    SciTech Connect

    Brice, D.A.; Nixon, J. . Fernald Environmental Management Project); Lewis, E.T. )

    1992-01-01

    Environmental investigations of the extent and effect of contamination, and projects to remediate such contamination, are designed to mitigate perceived threats to human health and the environment. During the course of these investigations, excavations, borings, and monitoring wells are constructed: monitoring wells are developed and purged prior to sampling; samples are collected; equipment is decontaminated; constituents extracted and analyzed; and personal protective equipment is used to keep workers safe. All of these activities generate waste. A large portion of this waste may be classified as hazardous based on characteristics or constituent components. Waste minimization is defined as reducing the volume and/or toxicity of waste generated by a process. Waste minimization has proven to be an effective means of cost reduction and improving worker health, safety, and environmental awareness in the industrial workplace through pollution prevention. Building waste minimization goals into a project during the planning phase is both cost effective and consistent with total quality management principles. Application of waste minimization principles should be an integral part of the planning and conduct of environmental investigations. Current regulatory guidance on planning environmental investigations focuses on data quality and risk assessment objectives. Waste minimization should also be a scoping priority, along with meeting worker protection requirements, protection of human health and the environment, and achieving data quality objectives. Waste volume or toxicity can be reduced through the use of smaller sample sizes, less toxic extraction solvents, less hazardous decontamination materials, smaller excavations and borings, smaller diameter monitoring wells, dedicated sampling equipment, well-fitting personal protective equipment, judicious use of screening technologies, and analyzing only for parameters of concern.

  2. Waste minimization in environmental sampling and analysis

    SciTech Connect

    Brice, D.A.; Nixon, J.; Lewis, E.T.

    1992-03-01

    Environmental investigations of the extent and effect of contamination, and projects to remediate such contamination, are designed to mitigate perceived threats to human health and the environment. During the course of these investigations, excavations, borings, and monitoring wells are constructed: monitoring wells are developed and purged prior to sampling; samples are collected; equipment is decontaminated; constituents extracted and analyzed; and personal protective equipment is used to keep workers safe. All of these activities generate waste. A large portion of this waste may be classified as hazardous based on characteristics or constituent components. Waste minimization is defined as reducing the volume and/or toxicity of waste generated by a process. Waste minimization has proven to be an effective means of cost reduction and improving worker health, safety, and environmental awareness in the industrial workplace through pollution prevention. Building waste minimization goals into a project during the planning phase is both cost effective and consistent with total quality management principles. Application of waste minimization principles should be an integral part of the planning and conduct of environmental investigations. Current regulatory guidance on planning environmental investigations focuses on data quality and risk assessment objectives. Waste minimization should also be a scoping priority, along with meeting worker protection requirements, protection of human health and the environment, and achieving data quality objectives. Waste volume or toxicity can be reduced through the use of smaller sample sizes, less toxic extraction solvents, less hazardous decontamination materials, smaller excavations and borings, smaller diameter monitoring wells, dedicated sampling equipment, well-fitting personal protective equipment, judicious use of screening technologies, and analyzing only for parameters of concern.

  3. 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.

  4. Protocol Improvements for Low Concentration DNA-Based Bioaerosol Sampling and Analysis

    PubMed Central

    Ng, Chun Kiat; Miller, Dana; Cao, Bin

    2015-01-01

    Introduction As bioaerosol research attracts increasing attention, there is a need for additional efforts that focus on method development to deal with different environmental samples. Bioaerosol environmental samples typically have very low biomass concentrations in the air, which often leaves researchers with limited options in choosing the downstream analysis steps, especially when culture-independent methods are intended. Objectives This study investigates the impacts of three important factors that can influence the performance of culture-independent DNA-based analysis in dealing with bioaerosol environmental samples engaged in this study. The factors are: 1) enhanced high temperature sonication during DNA extraction; 2) effect of sampling duration on DNA recoverability; and 3) an alternative method for concentrating composite samples. In this study, DNA extracted from samples was analysed using the Qubit fluorometer (for direct total DNA measurement) and quantitative polymerase chain reaction (qPCR). Results and Findings The findings suggest that additional lysis from high temperature sonication is crucial: DNA yields from both high and low biomass samples increased up to 600% when the protocol included 30-min sonication at 65°C. Long air sampling duration on a filter media was shown to have a negative impact on DNA recoverability with up to 98% of DNA lost over a 20-h sampling period. Pooling DNA from separate samples during extraction was proven to be feasible with margins of error below 30%. PMID:26619279

  5. '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.

  6. '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.

  7. '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.

  8. '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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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%.

  14. Novel Sample-handling Approach for XRD Analysis with Minimal Sample Preparation

    NASA Technical Reports Server (NTRS)

    Sarrazin, P.; Chipera, S.; Bish, D.; Blake, D.; Feldman, S.; Vaniman, D.; Bryson, C.

    2004-01-01

    Sample preparation and sample handling are among the most critical operations associated with X-ray diffraction (XRD) analysis. These operations require attention in a laboratory environment, but they become a major constraint in the deployment of XRD instruments for robotic planetary exploration. We are developing a novel sample handling system that dramatically relaxes the constraints on sample preparation by allowing characterization of coarse-grained material that would normally be impossible to analyze with conventional powder-XRD techniques.

  15. BMEWS Capture and Analysis of Reflected Energy Clear Air ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    BMEWS Capture and Analysis of Reflected Energy - Clear Air Force Station, Ballistic Missile Early Warning System Site II, One mile west of mile marker 293.5 on Parks Highway, 5 miles southwest of Anderson, Anderson, Denali Borough, AK

  16. Exomars 2018 Rover Pasteur Payload Sample Analysis

    NASA Astrophysics Data System (ADS)

    Debus, Andre; Bacher, M.; Ball, A.; Barcos, O.; Bethge, B.; Gaubert, F.; Haldemann, A.; Kminek, G.; Lindner, R.; Pacros, A.; Rohr, T.; Trautner, R.; Vago, J.

    The ExoMars programme is a joint ESA-NASA program having exobiology as one of the key science objectives. It is divided into 2 missions: the first mission is ESA-led with an ESA orbiter and an ESA Entry, Descent and Landing (EDL) demonstrator, launched in 2016 by NASA, and the second mission is NASA-led, launched in 2018 by NASA including an ESA rover and a NASA rover both deployed by a single NASA EDL system. For ESA, the ExoMars programme will demonstrate key flight and in situ enabling technologies in support of the European ambitions for future exploration missions, as outlined in the Aurora Declaration. The ExoMars 2018 ESA Rover will carry a comprehensive and coherent suite of analytical instruments dedicated to exobiology and geology research: the Pasteur Payload (PPL). This payload includes a selection of complementary instruments, having the following goals: to search for signs of past and present life on Mars and to investigate the water/geochemical environment as a function of depth in the shallow subsurface. The ExoMars Rover will travel several kilometres searching for sites warranting further investigation. The Rover includes a drill and a Sample Preparation and Distribution System which will be used to collect and analyse samples from within outcrops and from the subsurface. The Rover systems and instruments, in particular those located inside the Analytical Laboratory Drawer must meet many stringent requirements to be compatible with exobiologic investigations: the samples must be maintained in a cold and uncontaminated environment, requiring sterile and ultraclean preparation of the instruments, to preserve volatile materials and to avoid false positive results. The value of the coordinated observations suggests that a significant return on investment is to be expected from this complex development. We will present the challenges facing the ExoMars PPL, and the plans for sending a robust exobiology laboratory to Mars in 2018.

  17. Analysis of a Suspected Drug Sample

    ERIC Educational Resources Information Center

    Schurter, Eric J.; Zook-Gerdau, Lois Anne; Szalay, Paul

    2011-01-01

    This general chemistry laboratory uses differences in solubility to separate a mixture of caffeine and aspirin while introducing the instrumental analysis methods of GCMS and FTIR. The drug mixture is separated by partitioning aspirin and caffeine between dichloromethane and aqueous base. TLC and reference standards are used to identify aspirin…

  18. 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.

  19. Neutron activation analysis for antimetabolites. [in food samples

    NASA Technical Reports Server (NTRS)

    1973-01-01

    Determination of metal ion contaminants in food samples is studied. A weighed quantity of each sample was digested in a concentrated mixture of nitric, hydrochloric and perchloric acids to affect complete solution of the food products. The samples were diluted with water and the pH adjusted according to the specific analysis performed. The samples were analyzed by neutron activation analysis, polarography, and atomic absorption spectrophotometry. The solid food samples were also analyzed by neutron activation analysis for increased sensitivity and lower levels of detectability. The results are presented in tabular form.

  20. Modified electrokinetic sample injection method in chromatography and electrophoresis analysis

    DOEpatents

    Davidson, J. Courtney; Balch, Joseph W.

    2001-01-01

    A sample injection method for horizontal configured multiple chromatography or electrophoresis units, each containing a number of separation/analysis channels, that enables efficient introduction of analyte samples. This method for loading when taken in conjunction with horizontal microchannels allows much reduced sample volumes and a means of sample stacking to greatly reduce the concentration of the sample. This reduction in the amount of sample can lead to great cost savings in sample preparation, particularly in massively parallel applications such as DNA sequencing. The essence of this method is in preparation of the input of the separation channel, the physical sample introduction, and subsequent removal of excess material. By this method, sample volumes of 100 nanoliter to 2 microliters have been used successfully, compared to the typical 5 microliters of sample required by the prior separation/analysis method.

  1. 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.

  2. FORMAL UNCERTAINTY ANALYSIS OF A LAGRANGIAN PHOTOCHEMICAL AIR POLLUTION MODEL. (R824792)

    EPA Science Inventory

    This study applied Monte Carlo analysis with Latin
    hypercube sampling to evaluate the effects of uncertainty
    in air parcel trajectory paths, emissions, rate constants,
    deposition affinities, mixing heights, and atmospheric stability
    on predictions from a vertically...

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. Task analysis of Air Force pharmacy practice.

    PubMed

    Bartholomew, A; Sawyer, W T; Coats, L

    1995-01-15

    The frequency with which United States Air Force pharmacists perform specific professional tasks and the pharmacists' views as to the importance of those tasks were studied. A questionnaire was prepared that asked recipients to rate each of 36 tasks selected as representing the spectrum of practice activities. There were four categories of tasks: managerial tasks, dispensing tasks, drug information tasks, and patient care tasks. Recipients rated the tasks with respect to frequency of performance and importance on separate 6-point scales. The questionnaire was mailed in May 1991 to the 225 pharmacists then serving in the Air Force worldwide. Of the 225 questionnaires, 150 usable questionnaires were returned (response rate, 67%). All the tasks in the survey were performed by at least one Air Force pharmacy officer, although the frequency of task performance varied. In particular, the frequency of many patient care tasks was low. All the tasks were perceived to have some importance, but drug information tasks were rated as being significantly more important than tasks in the other categories; patient care tasks were rated lowest in importance. The results varied with the respondents' demographic characteristics. Pharmacy officers with more years of service, more senior positions, higher rank, or an advanced degree in a field other than pharmacy tended to give responses that diverged from those of the population. A 1991 survey showed an awareness among Air Force pharmacists of the need to orient practice around patient care; however, they were not spending substantial time on patient care and tended to view it as less important than more traditional pharmacy tasks.

  8. 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.

  9. Combined analysis of job and task benzene air exposures among workers at four US refinery operations.

    PubMed

    Burns, Amanda; Shin, Jennifer Mi; Unice, Ken M; Gaffney, Shannon H; Kreider, Marisa L; Gelatt, Richard H; Panko, Julie M

    2017-03-01

    Workplace air samples analyzed for benzene at four US refineries from 1976 to 2007 were pooled into a single dataset to characterize similarities and differences between job titles, tasks and refineries, and to provide a robust dataset for exposure reconstruction. Approximately 12,000 non-task (>180 min) personal samples associated with 50 job titles and 4000 task (<180 min) samples characterizing 24 tasks were evaluated. Personal air sample data from four individual refineries were pooled based on a number of factors including (1) the consistent sampling approach used by refinery industrial hygienists over time, (2) the use of similar exposure controls, (3) the comparability of benzene content of process streams and end products, (4) the ability to assign uniform job titles and task codes across all four refineries, and (5) our analysis of variance (ANOVA) of the distribution of benzene air concentrations for select jobs/tasks across all four refineries. The jobs and tasks most frequently sampled included those with highest potential contact with refinery product streams containing benzene, which reflected the targeted sampling approach utilized by the facility industrial hygienists. Task and non-task data were analyzed to identify and account for significant differences within job-area, task-job, and task-area categories. This analysis demonstrated that in general, areas with benzene containing process streams were associated with greater benzene air concentrations compared to areas with process streams containing little to no benzene. For several job titles and tasks analyzed, there was a statistically significant decrease in benzene air concentration after 1990. This study provides a job and task-focused analysis of occupational exposure to benzene during refinery operations, and it should be useful for reconstructing refinery workers' exposures to benzene over the past 30 years.

  10. ENVIRONMENTAL SAMPLING AND ANALYSIS - GETTING IT RIGHT

    SciTech Connect

    CONNELL CW

    2008-01-22

    The Department of Energy's Hanford Site in southeastern Washington State was established in the 1940s as part of the Manhattan Project. Hanford's role was to produce weapons-grade nuclear material for defense, and by 1989, when the Site's mission changed from operations to cleanup, Hanford had produced more than 60 percent of the nation's plutonium. The legacy of Hanford's production years is enormous in terms of nuclear and hazardous waste, especially the 270 billion gallons of contaminated groundwater and the 5 million cubic yards of contaminated soil. Managing the contaminated soil and groundwater are particularly important because the Columbia River, the lifeblood of the northwest and the nation's eighth largest river, bounds the Site. Fluor Hanford's Soil & Groundwater Remediation Project (S&GRP) integrates all of the activities that deal with remediating and monitoring the groundwater across the Site. The S&GRP uses a detailed series of steps to record, track, and verify information. The Sample and Data Management (SDM) Process consists of 10 integrated steps that start with the data quality objectives process that establishes the mechanism for collecting the right information with the right people. The process ends with data quality assessment, which is used to ensure that all quantitative data (e.g., field screening, fixed laboratory) are the right type, and of adequate quality to support the decision-making process. Steps 3 through 10 of the process are production steps and are integrated electronically. The detailed plans, procedures, and systems used day-to-day by the SDM process require a high degree of accuracy and reliability. Tools must be incorporated into the processes that minimize errors. This paper discusses all of the elements of the SDM process in detail.

  11. 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.

  12. 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

  13. 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.

  14. Air-to-air combat analysis - Review of differential-gaming approaches

    NASA Technical Reports Server (NTRS)

    Ardema, M. D.

    1981-01-01

    The problem of evaluating the combat performance of fighter/attack aircraft is discussed, and the mathematical nature of the problem is examined. The following approaches to air combat analysis are reviewed: (1) differential-turning differential game and (2) coplanar differential game. Selected numerical examples of these approaches are presented. The relative advantages and disadvantages of each are analyzed, and it is concluded that air combat analysis is an extremely difficult mathematical problem and that no one method of approach is best for all purposes. The paper concludes with a discussion of how the two approaches might be used in a complementary manner.

  15. Real-time Sample Analysis using Sampling Probe and Miniature Mass Spectrometer

    PubMed Central

    Chen, Chien-Hsun; Lin, Ziqing; Tian, Ran; Shi, Riyi; Cooks, R. Graham; Ouyang, Zheng

    2016-01-01

    A miniature mass spectrometry system with a sampling probe has been developed for real-time analysis of chemicals from sample surfaces. The sampling probe is 1.5m in length and is comprised of one channel for introducing the spray and the other channel for transferring the charged species back to the Mini MS. This system provides a solution to the problem of real-time mass spectrometry analysis of a three-dimensional object in the field and is successful with compounds including those in inks, agrochemicals, explosives, and animal tissues. This system can be implemented in the form of a backpack MS with a sampling probe for forensic analysis or in the form of a compact MS with an intra-surgical probe for tissue analysis. PMID:26237577

  16. 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.

  17. 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.

  18. 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.

  19. 40 CFR 86.1340-90 - Exhaust sample analysis.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... sample analysis perform the following sequence: (1) Warm-up and stabilize the analyzers; clean and/or... sample analysis perform the following sequence: (1) Warm-up and stabilize the analyzers; clean and/or... lines, filters, pumps, etc., to stabilize at operating temperature. (3) Optional: Perform a...

  20. 40 CFR 86.1340-90 - Exhaust sample analysis.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... sample analysis perform the following sequence: (1) Warm-up and stabilize the analyzers; clean and/or... sample analysis perform the following sequence: (1) Warm-up and stabilize the analyzers; clean and/or... lines, filters, pumps, etc., to stabilize at operating temperature. (3) Optional: Perform a...

  1. 40 CFR 600.112-78 - Exhaust sample analysis.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... FUEL ECONOMY AND CARBON-RELATED EXHAUST EMISSIONS OF MOTOR VEHICLES Fuel Economy Regulations for 1978 and Later Model Year Automobiles-Test Procedures § 600.112-78 Exhaust sample analysis. The exhaust... 40 Protection of Environment 29 2010-07-01 2010-07-01 false Exhaust sample analysis....

  2. 40 CFR 600.112-08 - Exhaust sample analysis.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... FUEL ECONOMY AND CARBON-RELATED EXHAUST EMISSIONS OF MOTOR VEHICLES Fuel Economy Regulations for 1978 and Later Model Year Automobiles-Test Procedures § 600.112-08 Exhaust sample analysis. The exhaust... 40 Protection of Environment 29 2010-07-01 2010-07-01 false Exhaust sample analysis....

  3. Selenium sampling and analysis in coal combustion systems

    SciTech Connect

    DeVito, M.S.; Carlson, R.J.

    1995-12-31

    The Clean Air Act Amendments of 1990 (CAAA) identified 189 elements and compounds that are classified by the U.S. EPA as hazardous air pollutants (HAPs). Among these are eleven inorganic trace elements found in coal. A provision of the CAAA required EPA to conduct a study of the health and environmental impacts of HAP emissions from electric utility generating units. EPA has completed a number of draft documents in compliance with this mandate. For trace element emission estimates, they have relied on a number of field tests which were conducted by a variety of organizations including the U.S. Department of Energy (DOE). The DOE program utilized the EPA Method 29 sampling train to measure the emissions of trace elements including Se. EPA Method 29 is validated for municipal waste combustor sampling but not for coal-fired combustion sources.

  4. Spatial analysis of the tuberculosis treatment dropout, Buenos Aires, Argentina.

    PubMed

    Herrero, María Belén; Arrossi, Silvina; Ramos, Silvina; Braga, Jose Ueleres

    2015-01-01

    OBJECTIVE Identify spatial distribution patterns of the proportion of nonadherence to tuberculosis treatment and its associated factors. METHODS We conducted an ecological study based on secondary and primary data from municipalities of the metropolitan area of Buenos Aires, Argentina. An exploratory analysis of the characteristics of the area and the distributions of the cases included in the sample (proportion of nonadherence) was also carried out along with a multifactor analysis by linear regression. The variables related to the characteristics of the population, residences and families were analyzed. RESULTS Areas with higher proportion of the population without social security benefits (p = 0.007) and of households with unsatisfied basic needs had a higher risk of nonadherence (p = 0.032). In addition, the proportion of nonadherence was higher in areas with the highest proportion of households with no public transportation within 300 meters (p = 0.070). CONCLUSIONS We found a risk area for the nonadherence to treatment characterized by a population living in poverty, with precarious jobs and difficult access to public transportation.

  5. Spatial analysis of the tuberculosis treatment dropout, Buenos Aires, Argentina

    PubMed Central

    Herrero, María Belén; Arrossi, Silvina; Ramos, Silvina; Braga, Jose Ueleres

    2015-01-01

    OBJECTIVE Identify spatial distribution patterns of the proportion of nonadherence to tuberculosis treatment and its associated factors. METHODS We conducted an ecological study based on secondary and primary data from municipalities of the metropolitan area of Buenos Aires, Argentina. An exploratory analysis of the characteristics of the area and the distributions of the cases included in the sample (proportion of nonadherence) was also carried out along with a multifactor analysis by linear regression. The variables related to the characteristics of the population, residences and families were analyzed. RESULTS Areas with higher proportion of the population without social security benefits (p = 0.007) and of households with unsatisfied basic needs had a higher risk of nonadherence (p = 0.032). In addition, the proportion of nonadherence was higher in areas with the highest proportion of households with no public transportation within 300 meters (p = 0.070). CONCLUSIONS We found a risk area for the nonadherence to treatment characterized by a population living in poverty, with precarious jobs and difficult access to public transportation. PMID:26270011

  6. Indoor air quality analysis based on Hadoop

    NASA Astrophysics Data System (ADS)

    Tuo, Wang; Yunhua, Sun; Song, Tian; Liang, Yu; Weihong, Cui

    2014-03-01

    The air of the office environment is our research object. The data of temperature, humidity, concentrations of carbon dioxide, carbon monoxide and ammonia are collected peer one to eight seconds by the sensor monitoring system. And all the data are stored in the Hbase database of Hadoop platform. With the help of HBase feature of column-oriented store and versioned (automatically add the time column), the time-series data sets are bulit based on the primary key Row-key and timestamp. The parallel computing programming model MapReduce is used to process millions of data collected by sensors. By analysing the changing trend of parameters' value at different time of the same day and at the same time of various dates, the impact of human factor and other factors on the room microenvironment is achieved according to the liquidity of the office staff. Moreover, the effective way to improve indoor air quality is proposed in the end of this paper.

  7. Chemical trends in background air quality and the ionic composition of precipitation for the period 1980-2004 from samples collected at Valentia Observatory, Co. Kerry, Ireland.

    PubMed

    Bashir, Wasim; McGovern, Frank; O'Brien, Phillip; Ryan, Margaret; Burke, Liam; Paull, Brett

    2008-06-01

    A major Irish study, based upon more than 8000 samples collected over the measurement period of 22 years, for sulfur dioxide (SO2-S), sulfate (SO4-S) and nitrogen dioxide (NO2-N) concentrations (microg m(-3)) within air, and the ionic composition of precipitation samples based on sodium (Na+), potassium (K+), magnesium (Mg2+), calcium (Ca2+), chloride (Cl-), sulfate (SO4-S), non-sea salt sulfate (nssSO4-S), ammonium (NH4-N), and nitrate (NO3-N) weighted mean concentrations (mg l(-1)), has been completed. For the air samples, the sulfur dioxide and sulfate concentrations decreased over the sampling period (1980-2004) by 75% and 45%, respectively, whereas no significant trend was observed for nitrogen dioxide. The highest concentrations for sulfur dioxide, sulfate and nitrogen dioxide were associated with wind originating from the easterly and northeasterly directions i.e. those influenced by Irish and European sources. The lowest concentrations were associated with the westerly directions i.e. for air masses originating in the North Atlantic region. This was further verified with the use of backward (back) trajectory analysis, which allowed tracing the movement of air parcels using the European Centre for Medium range Weather Forecasting (ECMWF) ERA-40 re-analysis data. High non-sea salt sulfate levels were being associated with air masses originating from Europe (easterlies) with lower levels from the Atlantic (westerlies). With the precipitation data, analysis of the non-sea salt sulfate concentrations showed a decrease by 47% since the measurements commenced.

  8. Accelerating analysis for metabolomics, drugs and their metabolites in biological samples using multidimensional gas chromatography.

    PubMed

    Mitrevski, Blagoj S; Kouremenos, Konstantinos A; Marriott, Philip J

    2009-05-01

    Gas chromatography (GC) with mass spectrometry (MS) is one of the great enabling analytical tools available to the chemical and biochemical analyst for the measurement of volatile and semi-volatile compounds. From the analysis result, it is possible to assess progress in chemical reactions, to monitor environmental pollutants in a wide range of soil, water or air samples, to determine if an athlete or horse trainer has contravened doping laws, or if crude oil has migrated through subsurface rock to a reservoir. Each of these scenarios and samples has an associated implementation method for GC-MS. However, few samples and the associated interpretation of data is as complex or important as biochemical sample analysis for trace drugs or metabolites. Improving the analysis in both the GC and MS domains is a continual search for better separation, selectivity and sensitivity. Multidimensional methods are playing important roles in providing quality data to address the needs of analysts.

  9. Analysis of organic compounds in returned comet nucleus samples

    NASA Technical Reports Server (NTRS)

    Cronin, J. R.

    1989-01-01

    Techniques for analysis of organic compounds in returned comet nucleus samples are described. Interstellar, chondritic and transitional organic components are discussed. Appropriate sampling procedures will be essential to the success of these analyses. It will be necessary to return samples that represent all the various regimes found in the nucleus, e.g., a complete core, volatile components (deep interior), and crustal components (surface minerals, rocks, processed organics such as macromolecular carbon and polymers). Furthermore, sampling, storage, return, and distribution of samples must be done under conditions that preclude contamination of the samples by terrestrial matter.

  10. Enhanced AFCI Sampling, Analysis, and Safeguards Technology Review

    SciTech Connect

    John Svoboda

    2009-09-01

    The focus of this study includes the investigation of sampling technologies used in industry and their potential application to nuclear fuel processing. The goal is to identify innovative sampling methods using state of the art techniques that could evolve into the next generation sampling and analysis system for metallic elements. Sampling and analysis of nuclear fuel recycling plant processes is required both to monitor the operations and ensure Safeguards and Security goals are met. In addition, environmental regulations lead to additional samples and analysis to meet licensing requirements. The volume of samples taken by conventional means, can restrain productivity while results samples are analyzed, require process holding tanks that are sized to meet analytical issues rather than process issues (and that create a larger facility footprint), or, in some cases, simply overwhelm analytical laboratory capabilities. These issues only grow when process flowsheets propose new separations systems and new byproduct material for transmutation purposes. Novel means of streamlining both sampling and analysis are being evaluated to increase the efficiency while meeting all requirements for information. This report addresses just a part of the effort to develop and study novel methods by focusing on the sampling and analysis of aqueous samples for metallic elements. It presents an overview of the sampling requirements, including frequency, sensitivity, accuracy, and programmatic drivers, to demonstrate the magnitude of the task. The sampling and analysis system needed for metallic element measurements is then discussed, and novel options being applied to other industrial analytical needs are presented. Inductively coupled mass spectrometry instruments are the most versatile for metallic element analyses and are thus chosen as the focus for the study. Candidate novel means of process sampling, as well as modifications that are necessary to couple such instruments to

  11. Analysis of the research sample collections of Uppsala biobank.

    PubMed

    Engelmark, Malin T; Beskow, Anna H

    2014-10-01

    Uppsala Biobank is the joint and only biobank organization of the two principals, Uppsala University and Uppsala University Hospital. Biobanks are required to have updated registries on sample collection composition and management in order to fulfill legal regulations. We report here the results from the first comprehensive and overall analysis of the 131 research sample collections organized in the biobank. The results show that the median of the number of samples in the collections was 700 and that the number of samples varied from less than 500 to over one million. Blood samples, such as whole blood, serum, and plasma, were included in the vast majority, 84.0%, of the research sample collections. Also, as much as 95.5% of the newly collected samples within healthcare included blood samples, which further supports the concept that blood samples have fundamental importance for medical research. Tissue samples were also commonly used and occurred in 39.7% of the research sample collections, often combined with other types of samples. In total, 96.9% of the 131 sample collections included samples collected for healthcare, showing the importance of healthcare as a research infrastructure. Of the collections that had accessed existing samples from healthcare, as much as 96.3% included tissue samples from the Department of Pathology, which shows the importance of pathology samples as a resource for medical research. Analysis of different research areas shows that the most common of known public health diseases are covered. Collections that had generated the most publications, up to over 300, contained a large number of samples collected systematically and repeatedly over many years. More knowledge about existing biobank materials, together with public registries on sample collections, will support research collaborations, improve transparency, and bring us closer to the goals of biobanks, which is to save and prolong human lives and improve health and quality of life.

  12. Problems in the sampling and analysis of carbon particulate

    NASA Astrophysics Data System (ADS)

    Cadle, Steven H.; Groblicki, Peter J.; Mulawa, Patricia A.

    Several thermal and wet chemical methods of separating organic from elemental carbon in particulate samples were examined. It is concluded that none of them represents an ideal separation procedure and that only a method-dependent operational definition of organic and elemental carbon is possible at this time. The best separation method appears to be a thermal procedure using 350°C air oxidation followed by pyrolysis in He at 950°C. There are also difficulties in sampling since dual filter techniques show that adsorption of organic compounds on various filter media accounted for at least 15 per cent of the total organic carbon collected during ambient sampling in Warren, MI. This adsorption further confuses the results and needs to be studied at other sampling sites.

  13. 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.

  14. Efficiency of Airborne Sample Analysis Platform (ASAP) bioaerosol sampler for pathogen detection

    PubMed Central

    Sharma, Anurag; Clark, Elizabeth; McGlothlin, James D.; Mittal, Suresh K.

    2015-01-01

    The threat of bioterrorism and pandemics has highlighted the urgency for rapid and reliable bioaerosol detection in different environments. Safeguarding against such threats requires continuous sampling of the ambient air for pathogen detection. In this study we investigated the efficacy of the Airborne Sample Analysis Platform (ASAP) 2800 bioaerosol sampler to collect representative samples of air and identify specific viruses suspended as bioaerosols. To test this concept, we aerosolized an innocuous replication-defective bovine adenovirus serotype 3 (BAdV3) in a controlled laboratory environment. The ASAP efficiently trapped the surrogate virus at 5 × 103 plaque-forming units (p.f.u.) [2 × 105 genome copy equivalent] concentrations or more resulting in the successful detection of the virus using quantitative PCR. These results support the further development of ASAP for bioaerosol pathogen detection. PMID:26074900

  15. Theory of sampling: four critical success factors before analysis.

    PubMed

    Wagner, Claas; Esbensen, Kim H

    2015-01-01

    Food and feed materials characterization, risk assessment, and safety evaluations can only be ensured if QC measures are based on valid analytical data, stemming from representative samples. The Theory of Sampling (TOS) is the only comprehensive theoretical framework that fully defines all requirements to ensure sampling correctness and representativity, and to provide the guiding principles for sampling in practice. TOS also defines the concept of material heterogeneity and its impact on the sampling process, including the effects from all potential sampling errors. TOS's primary task is to eliminate bias-generating errors and to minimize sampling variability. Quantitative measures are provided to characterize material heterogeneity, on which an optimal sampling strategy should be based. Four critical success factors preceding analysis to ensure a representative sampling process are presented here.

  16. Construction Site Storm Water Sampling California's New Construction Sampling and Analysis Requirements

    SciTech Connect

    Forrest, C.L.; Mathews, S.

    2002-04-02

    The California State Water Resources Control Board (State Board) originally issued a National Pollutant Discharge System (NPDES) permit for storm water discharges associated with construction activities in 1992. This NPDES permit was issued as a general permit, applicable throughout the state (with certain exceptions). The general construction permit was made site-specific by a discharger-developed Storm Water Pollution Prevention Plan (SWPPP). As with most NPDES construction storm water permits, monitoring requirements were limited to inspections. Sampling and analysis of discharges was not specifically required, but a Regional Water Quality Control Board (Regional Board) could require additional monitoring. In 1999, the State -Board revised and reissued its construction general permit. While the 1999 permit significantly enhanced the erosion and sediment control descriptions and requirements, and expanded the inspection program, sampling and analysis was still not required. Environmental advocacy groups took exception to the absence of sampling requirements and sought relief in court to add sampling and analysis. In 2001, the State Board in response to the court order adopted a resolution requiring sampling and analysis of construction site runoff under two conditions. Turbidity and/or sediment sampling is required when construction site runoff enters water bodies determined to impaired for sediment or turbidity. Sampling for non-visible pollutants is required when construction operations expose materials to storm water. Sampling construction site runoff is relatively new concept for NPDES permits. Only a few permits throughout the country require sampling and analysis for sediment-related pollutants, and California is one of the only permitting entities to require sampling for non-visible pollutants in construction site runoff. The added complexity of sampling runoff requires construction operators and erosion and sediment control professionals to expand their

  17. Preparation, certification and interlaboratory analysis of workplace air filters spiked with high-fired beryllium oxide.

    PubMed

    Oatts, Thomas J; Hicks, Cheryl E; Adams, Amy R; Brisson, Michael J; Youmans-McDonald, Linda D; Hoover, Mark D; Ashley, Kevin

    2012-02-01

    Occupational sampling and analysis for multiple elements is generally approached using various approved methods from authoritative government sources such as the National Institute for Occupational Safety and Health (NIOSH), the Occupational Safety and Health Administration (OSHA) and the Environmental Protection Agency (EPA), as well as consensus standards bodies such as ASTM International. The constituents of a sample can exist as unidentified compounds requiring sample preparation to be chosen appropriately, as in the case of beryllium in the form of beryllium oxide (BeO). An interlaboratory study was performed to collect analytical data from volunteer laboratories to examine the effectiveness of methods currently in use for preparation and analysis of samples containing calcined BeO powder. NIST SRM(®) 1877 high-fired BeO powder (1100 to 1200 °C calcining temperature; count median primary particle diameter 0.12 μm) was used to spike air filter media as a representative form of beryllium particulate matter present in workplace sampling that is known to be resistant to dissolution. The BeO powder standard reference material was gravimetrically prepared in a suspension and deposited onto 37 mm mixed cellulose ester air filters at five different levels between 0.5 μg and 25 μg of Be (as BeO). Sample sets consisting of five BeO-spiked filters (in duplicate) and two blank filters, for a total of twelve unique air filter samples per set, were submitted as blind samples to each of 27 participating laboratories. Participants were instructed to follow their current process for sample preparation and utilize their normal analytical methods for processing samples containing substances of this nature. Laboratories using more than one sample preparation and analysis method were provided with more than one sample set. Results from 34 data sets ultimately received from the 27 volunteer laboratories were subjected to applicable statistical analyses. The observed

  18. STATISTICAL ANALYSIS OF TANK 19F FLOOR SAMPLE RESULTS

    SciTech Connect

    Harris, S.

    2010-09-02

    Representative sampling has been completed for characterization of the residual material on the floor of Tank 19F as per the statistical sampling plan developed by Harris and Shine. Samples from eight locations have been obtained from the tank floor and two of the samples were archived as a contingency. Six samples, referred to in this report as the current scrape samples, have been submitted to and analyzed by SRNL. This report contains the statistical analysis of the floor sample analytical results to determine if further data are needed to reduce uncertainty. Included are comparisons with the prior Mantis samples results to determine if they can be pooled with the current scrape samples to estimate the upper 95% confidence limits (UCL95%) for concentration. Statistical analysis revealed that the Mantis and current scrape sample results are not compatible. Therefore, the Mantis sample results were not used to support the quantification of analytes in the residual material. Significant spatial variability among the current scrape sample results was not found. Constituent concentrations were similar between the North and South hemispheres as well as between the inner and outer regions of the tank floor. The current scrape sample results from all six samples fall within their 3-sigma limits. In view of the results from numerous statistical tests, the data were pooled from all six current scrape samples. As such, an adequate sample size was provided for quantification of the residual material on the floor of Tank 19F. The uncertainty is quantified in this report by an UCL95% on each analyte concentration. The uncertainty in analyte concentration was calculated as a function of the number of samples, the average, and the standard deviation of the analytical results. The UCL95% was based entirely on the six current scrape sample results (each averaged across three analytical determinations).

  19. STATISTICAL ANALYSIS OF TANK 18F FLOOR SAMPLE RESULTS

    SciTech Connect

    Harris, S.

    2010-09-02

    Representative sampling has been completed for characterization of the residual material on the floor of Tank 18F as per the statistical sampling plan developed by Shine [1]. Samples from eight locations have been obtained from the tank floor and two of the samples were archived as a contingency. Six samples, referred to in this report as the current scrape samples, have been submitted to and analyzed by SRNL [2]. This report contains the statistical analysis of the floor sample analytical results to determine if further data are needed to reduce uncertainty. Included are comparisons with the prior Mantis samples results [3] to determine if they can be pooled with the current scrape samples to estimate the upper 95% confidence limits (UCL{sub 95%}) for concentration. Statistical analysis revealed that the Mantis and current scrape sample results are not compatible. Therefore, the Mantis sample results were not used to support the quantification of analytes in the residual material. Significant spatial variability among the current sample results was not found. Constituent concentrations were similar between the North and South hemispheres as well as between the inner and outer regions of the tank floor. The current scrape sample results from all six samples fall within their 3-sigma limits. In view of the results from numerous statistical tests, the data were pooled from all six current scrape samples. As such, an adequate sample size was provided for quantification of the residual material on the floor of Tank 18F. The uncertainty is quantified in this report by an upper 95% confidence limit (UCL{sub 95%}) on each analyte concentration. The uncertainty in analyte concentration was calculated as a function of the number of samples, the average, and the standard deviation of the analytical results. The UCL{sub 95%} was based entirely on the six current scrape sample results (each averaged across three analytical determinations).

  20. Analysis of hydrogen cyanide in air in a case of attempted cyanide poisoning.

    PubMed

    Magnusson, R; Nyholm, S; Åstot, C

    2012-10-10

    A 32-year-old man attempted to poison his ex-girlfriend with hydrogen cyanide by hiding the pesticide Uragan D2 in her car. During the police investigation, chemical analysis of the air inside the car was performed. Hydrogen cyanide was detected through on-site air analysis using a portable Fourier transform infrared (FTIR) spectroscopy gas analyzer and colorimetric gas detection tubes. Furthermore, impinger air-sampling was performed for off-site sample preparation and analysis by gas chromatography-mass spectrometry (GC-MS). All three independent techniques demonstrated the presence of hydrogen cyanide, at concentrations of 14-20 ppm. Owing to the high volatility of hydrogen cyanide, the temperature and the time since exposure have a substantial effect on the likelihood of detecting hydrogen cyanide at a crime scene. The prevailing conditions (closed space, low temperature) must have supported the preservation of HCN in the car thus enabling the identification even though the analysis was performed several days after the hydrogen cyanide source was removed. This paper demonstrates the applicability of combining on-site FTIR measurements and off-site GC-MS analysis of a crime scene in order to ensure fast detection as well as unambiguous identification for forensic purposes of hydrogen cyanide in air.

  1. Comparison of passive diffusion bag samplers and submersible pump sampling methods for monitoring volatile organic compounds in ground water at Area 6, Naval Air Station, Whidbey Island, Washington

    USGS Publications Warehouse

    Huffman, Raegan L.

    2002-01-01

    Ground-water samples were collected in April 1999 at Naval Air Station Whidbey Island, Washington, with passive diffusion samplers and a submersible pump to compare concentrations of volatile organic compounds (VOCs) in water samples collected using the two sampling methods. Single diffusion samplers were installed in wells with 10-foot screened intervals, and multiple diffusion samplers were installed in wells with 20- to 40-foot screened intervals. The diffusion samplers were recovered after 20 days and the wells were then sampled using a submersible pump. VOC concentrations in the 10-foot screened wells in water samples collected with diffusion samplers closely matched concentrations in samples collected with the submersible pump. Analysis of VOC concentrations in samples collected from the 20- to 40-foot screened wells with multiple diffusion samplers indicated vertical concentration variation within the screened interval, whereas the analysis of VOC concentrations in samples collected with the submersible pump indicated mixing during pumping. The results obtained using the two sampling methods indicate that the samples collected with the diffusion samplers were comparable with and can be considerably less expensive than samples collected using a submersible pump.

  2. UMTRA water sampling and analysis plan, Lakeview, Oregon

    SciTech Connect

    Not Available

    1993-09-29

    The purpose of this document is to provide background, guidance, and justification for water sampling activities for the Lakeview, Oregon, Uranium Mill Tailings Remedial Action (UMTRA) processing and disposal sites. This water sampling and analysis plan will form the basis for groundwater sampling and analysis work orders (WSAWO) to be implemented during 1993. Monitoring at the former Lakeview processing site is for characterization purposes and in preparation for the risk assessment, scheduled for the fall of 1993. Compliance monitoring was conducted at the disposal site. Details of the sampling plan are discussed in Section 5.0.

  3. Modular Automated Processing System (MAPS) for analysis of biological samples.

    SciTech Connect

    Gil, Geun-Cheol; Chirica, Gabriela S.; Fruetel, Julia A.; VanderNoot, Victoria A.; Branda, Steven S.; Schoeniger, Joseph S.; Throckmorton, Daniel J.; Brennan, James S.; Renzi, Ronald F.

    2010-10-01

    We have developed a novel modular automated processing system (MAPS) that enables reliable, high-throughput analysis as well as sample-customized processing. This system is comprised of a set of independent modules that carry out individual sample processing functions: cell lysis, protein concentration (based on hydrophobic, ion-exchange and affinity interactions), interferent depletion, buffer exchange, and enzymatic digestion of proteins of interest. Taking advantage of its unique capacity for enclosed processing of intact bioparticulates (viruses, spores) and complex serum samples, we have used MAPS for analysis of BSL1 and BSL2 samples to identify specific protein markers through integration with the portable microChemLab{trademark} and MALDI.

  4. Workshop on Analysis of Returned Comet Nucleus Samples

    NASA Technical Reports Server (NTRS)

    1989-01-01

    This volume contains abstracts that were accepted by the Program Committee for presentation at the workshop on the analysis of returned comet nucleus samples held in Milpitas, California, January 16 to 18, 1989. The abstracts deal with the nature of cometary ices, cryogenic handling and sampling equipment, origin and composition of samples, and spectroscopic, thermal and chemical processing methods of cometary nuclei. Laboratory simulation experimental results on dust samples are reported. Some results obtained from Halley's comet are also included. Microanalytic techniques for examining trace elements of cometary particles, synchrotron x ray fluorescence and instrument neutron activation analysis (INAA), are presented.

  5. Evaluation of tetraglyme for the enrichment and analysis of volatile organic compounds in air.

    PubMed

    Huybrechts, T; Dewulf, J; Van Craeynest, K; Van Langenhove, H

    2001-07-13

    A recently developed method for the sampling and analysis of volatile organic compounds in air has been evaluated. The system is based on the enrichment of analytes in tetraethylene glycol dimethyl ether or tetraglyme, a water-soluble organic liquid. The subsequent analysis consists of dispersion of a sample aliquot in water followed by purge-and-trap and gas chromatographic separation. Physico-chemical data were investigated for 10 volatile organic compounds, providing information on the possibilities and limitations of the tetraglyme method. The target analytes included chlorinated alkanes and alkenes, and monocyclic aromatic hydrocarbons. Air/tetraglyme partition coefficients Kat were determined over an environmental relevant temperature range of 2-25 degrees C to evaluate sorption efficiencies and estimate breakthrough volumes at the sampling stage. At 2 degrees C breakthrough volumes (allowing 5% of breakthrough) ranged from 5.8 (1,1-dichloroethane) to 312 l (1,1,2-trichloroethane) for 20 ml of tetraglyme. With regard to the desorption stage, the effect of tetraglyme on the air/water partition of organic compounds was investigated through the measurement of air/tetraglyme-water partition coefficients Kat-w for 2-31% (v/v) tetraglyme in water. Finally a clean-up procedure for tetraglyme was evaluated. Analysis of a blank tetraglyme-water (17:83, v:v) mixture by gas chromatography-flame ionization detection/mass spectrometry showed minor background signals. None of the target compounds were detected.

  6. Air pollution and venous thrombosis: a meta-analysis

    PubMed Central

    Tang, Liang; Wang, Qing-Yun; Cheng, Zhi-Peng; Hu, Bei; Liu, Jing-Di; Hu, Yu

    2016-01-01

    Exposure to air pollution has been linked to cardiovascular and respiratory disorders. However, the effect of air pollution on venous thrombotic disorders is uncertain. We performed a meta-analysis to assess the association between air pollution and venous thrombosis. PubMed, Embase, EBM Reviews, Healthstar, Global Health, Nursing Database, and Web of Science were searched for citations on air pollutants (carbon monoxide, sulfur dioxide, nitrogen dioxide, ozone, and particulate matters) and venous thrombosis. Using a random-effects model, overall risk estimates were derived for each increment of 10 μg/m3 of pollutant concentration. Of the 485 in-depth reviewed studies, 8 citations, involving approximately 700,000 events, fulfilled the inclusion criteria. All the main air pollutants analyzed were not associated with an increased risk of venous thrombosis (OR = 1.005, 95% CI = 0.998–1.012 for PM2.5; OR = 0.995, 95% CI = 0.984–1.007 for PM10; OR = 1.006, 95% CI = 0.994–1.019 for NO2). Based on exposure period and thrombosis location, additional subgroup analyses provided results comparable with those of the overall analyses. There was no evidence of publication bias. Therefore, this meta analysis does not suggest the possible role of air pollution as risk factor for venous thrombosis in general population. PMID:27600652

  7. Variability and specificity associated with environmental methamphetamine sampling and analysis.

    PubMed

    Van Dyke, Mike V; Serrano, Kate A; Kofford, Shalece; Contreras, John; Martyny, John W

    2011-11-01

    This study was designed to explore the efficacy of the use of wipe sampling to determine methamphetamine contamination associated with the clandestine manufacture of methamphetamine. Three laboratories were utilized to analyze wipe samples to investigate variability in reported methamphetamine concentration among samples spiked with known amounts of methamphetamine. Different sampling media, surfaces, and solvents were also utilized to determine potential differences in measured methamphetamine concentration due to different wipes, wipe solvents, and wipe contaminants. This study examined rate of false positive detection among blank samples and whether interference with common household substances would create a false positive detection of methamphetamine. Variability between the three labs-using liquid chromatography with mass spectrometry or gas chromatography with mass spectrometry for detection of a known concentration of methamphetamine-resulted in percent differences of 3-30%. Results from wipe sample analysis for methamphetamine, using methanol or isopropanol, showed no significant difference in methamphetamine contamination recovery. Dust and paint contamination on methamphetamine wipe samples with known methamphetamine spike amounts did not affect methamphetamine wipe sample recovery. This study confirmed that either methanol or isopropanol is an appropriate solvent for use in methamphetamine wipe sampling. Dust and paint contamination on wipe samples will not interfere with the wipe sample analysis for methamphetamine. False positive detection for methamphetamine was not observed in any of the blank wipe samples submitted for the study. Finally, this study determined that methamphetamine will not be detected in structures that are truly methamphetamine free at current laboratory limits of quantification.

  8. Tank 241AP104 Grab Sampling and Analysis Plan

    SciTech Connect

    TEMPLETON, A.M.

    2000-11-09

    This sampling and analysis plan (SAP) identifies characterization objectives pertaining to sample collection, laboratory analytical evaluation, and reporting requirements for samples obtained from tank 241-AP-104. The purpose of this sampling event is to obtain information about the characteristics of the contents of 241-AP-104 required to provide sample material to the Waste Treatment Contractor. Grab samples will be obtained from riser 001 to provide sufficient material for the chemical analyses and tests required to satisfy these data quality objectives and ICD-23. The 222-S Laboratory will receive samples; composite the samples; perform chemical analyses on composite samples; and provide samples to the Waste Treatment Contractor and the Process Chemistry Laboratory. The Process Chemistry Laboratory at the 222-S Laboratory Complex will perform process tests to evaluate the behavior of the 241-AP-104 waste undergoing the retrieval and treatment scenarios defined in the applicable DQOs. The Waste Treatment Contractor will perform process verification and waste form qualification tests. Requirements for analyses of samples originating in the L & H DQO process tests will be documented in the corresponding test plan (Person 2000) and are not within the scope of this SAP. This report provides the general methodology and procedures to be used in the preparation, retrieval, transport, analysis, and reporting of results from grab samples retrieved from tank 241-AP-104.

  9. 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.

  10. Thermodynamic analysis and optimization of air-cooled heat exchangers

    NASA Astrophysics Data System (ADS)

    Salimpour, Mohammad Reza; Bahrami, Zabihollah

    2011-01-01

    In the present study, a thermodynamic second-law analysis was performed to investigate the effects of different geometry and flow parameters on the air-cooled heat exchanger performance. For this purpose, the entropy generation due to heat transfer and pressure loss of internal and external flows of the air-cooled heat exchanger was calculated; and it was observed that the total entropy generation has a minimum at special tube-side Reynolds number. Also, it was seen that the increasing of the tube-side Reynolds number resulted in the rise of the irreversibility of the air-cooled heat exchanger. The results also showed when air-side Reynolds number decreased, the entropy generation rate of the external flow reduced. Finally, based on the computed results, a new correlation was developed to predict the optimum Reynolds number of the tube-side fluid flow.

  11. A review of risk analysis and helicopter air ambulance accidents.

    PubMed

    Nix, Sam; Buckner, Steven; Cercone, Richard

    2014-01-01

    The Federal Aviation Administration announced a final rule in February 2014 that includes a requirement for helicopter air ambulance operators to institute preflight risk analysis programs. This qualitative study examined risk factors that were described in 22 preliminary, factual, and probable cause helicopter air ambulance accident and incident reports that were initiated by the National Transportation Safety Board between January 1, 2011, and December 31, 2013. Insights into the effectiveness of existing preflight risk analysis strategies were gained by comparing these risk factors with the preflight risk analysis guidance that is published by the Federal Aviation Administration in the Flight Standards Information Management System. When appropriate, a deeper understanding of the human factors that may have contributed to occurrences was gained through methodologies that are described in the Human Factors Analysis and Classification System. The results of this study suggest that there are some vulnerabilities in existing preflight risk analysis guidelines that may affect safety in the helicopter air ambulance industry. The likelihood that human factors contributed to most of the helicopter air ambulance accidents and incidents that occurred during the study period was also evidenced. The results of this study suggest that effective risk analysis programs should provide pilots with both preflight and in-flight resources.

  12. 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.

  13. Requirements for Minimum Sample Size for Sensitivity and Specificity Analysis

    PubMed Central

    Adnan, Tassha Hilda

    2016-01-01

    Sensitivity and specificity analysis is commonly used for screening and diagnostic tests. The main issue researchers face is to determine the sufficient sample sizes that are related with screening and diagnostic studies. Although the formula for sample size calculation is available but concerning majority of the researchers are not mathematicians or statisticians, hence, sample size calculation might not be easy for them. This review paper provides sample size tables with regards to sensitivity and specificity analysis. These tables were derived from formulation of sensitivity and specificity test using Power Analysis and Sample Size (PASS) software based on desired type I error, power and effect size. The approaches on how to use the tables were also discussed. PMID:27891446

  14. Integration of sample analysis method (SAM) for polychlorinated biphenyls

    SciTech Connect

    Monagle, M.; Johnson, R.C.

    1996-05-01

    A completely integrated Sample Analysis Method (SAM) has been tested as part of the Contaminant Analysis Automation program. The SAM system was tested for polychlorinated biphenyl samples using five Standard Laboratory Modules{trademark}: two Soxtec{trademark} modules, a high volume concentrator module, a generic materials handling module, and the gas chromatographic module. With over 300 samples completed within the first phase of the validation, recovery and precision data were comparable to manual methods. Based on experience derived from the first evaluation of the automated system, efforts are underway to improve sample recoveries and integrate a sample cleanup procedure. In addition, initial work in automating the extraction of semivolatile samples using this system will also be discussed.

  15. An analysis of candidates for addition to the Clean Air Act list of hazardous air pollutants.

    PubMed

    Lunder, Sonya; Woodruff, Tracey J; Axelrad, Daniel A

    2004-02-01

    There are 188 air toxics listed as hazardous air pollutants (HAPs) in the Clean Air Act (CAA), based on their potential to adversely impact public health. This paper presents several analyses performed to screen potential candidates for addition to the HAPs list. We analyzed 1086 HAPs and potential HAPs, including chemicals regulated by the state of California or with emissions reported to the Toxics Release Inventory (TRI). HAPs and potential HAPs were ranked by their emissions to air, and by toxicity-weighted (tox-wtd) emissions for cancer and noncancer, using emissions information from the TRI and toxicity information from state and federal agencies. Separate consideration was given for persistent, bioaccumulative toxins (PBTs), reproductive or developmental toxins, and chemicals under evaluation for regulation as toxic air contaminants in California. Forty-four pollutants were identified as candidate HAPs based on three ranking analyses and whether they were a PBT or a reproductive or developmental toxin. Of these, nine qualified in two or three different rankings (ammonia [NH3], copper [Cu], Cu compounds, nitric acid [HNO3], N-methyl-2-pyrrolidone, sulfuric acid [H2SO4], vanadium [V] compounds, zinc [Zn], and Zn compounds). This analysis suggests further evaluation of several pollutants for possible addition to the CAA list of HAPs.

  16. 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

  17. Design of experiments based variation mode and effect analysis of a conceptual air launched SLV

    NASA Astrophysics Data System (ADS)

    Rafique, Amer Farhan; Zeeshan, Qasim; Kamran, Ali

    2014-12-01

    Conceptual design stage is where the knowledge about the variation in system is still quite vague and herein we intend to analyze and compare various probable design concepts for Air Launched SLV by the use of basic variation mode and effect analysis. In this paper we present a methodology for the Variation Mode and Effect Analysis using Latin Hypercube Sampling based Design of Experiments for the conceptual Air launched Satellite Launch Vehicle. Variations are induced in the Control Variables based on knowledge and experience. The methodology is used to quantify the effect of Noise Factors on the performance of a conceptual Air Launched SLV. The insertion altitude of the Air Launched SLV is the Key Performance Indicator. Preliminary results of the performance and analysis for the simulated experiments are presented here. The performance of the proposed procedure has been tested and, thus, validated by the Air Launched SLV design problem. The Design of Experiment based Variation mode and effect analysis approach is intended for initial conceptual design purposes, thus, providing an immediate insight to the performance of the system in general and quantification of the sensitivity of the key performance indicator in particular, subject to the variations in noise factors prior to the detailed design phase.

  18. Soil sample preparation using microwave digestion for uranium analysis

    SciTech Connect

    MOHAGHEGHI,AMIR H.; PRESTON,ROSE; AKBARZADEH,MANSOOR; BAKHTIAR,STEVEN

    2000-04-05

    A new sample preparation procedure has been developed for digestion of soil samples for uranium analysis. The technique employs a microwave oven digestion system to digest the sample and to prepare it for separation chemistry and analysis. The method significantly reduces the volume of acids used, eliminates a large fraction of acid vapor emissions, and speeds up the analysis time. The samples are analyzed by four separate techniques: Gamma Spectrometry, Alpha Spectroscopy using the open digestion method, Kinetic Phosphorescence Analysis (KPA) using open digestion, and KPA by Microwave digestion technique. The results for various analytical methods are compared and used to confirm the validity of the new procedure. The details of the preparation technique along with its benefits are discussed.

  19. ALVEOLAR BREATH SAMPLING AND ANALYSIS IN HUMAN EXPOSURE ASSESSMENT STUDIES

    EPA Science Inventory

    Alveolar breath sampling and analysis can be extremely useful in exposure assessment studies involving volatile organic compounds (VOCs). Over recent years scientists from the EPA's National Exposure Research Laboratory have developed and refined an alveolar breath collection ...

  20. PANDA—A novel instrument for non-destructive sample analysis

    NASA Astrophysics Data System (ADS)

    Turunen, Jani; Peräjärvi, Kari; Pöllänen, Roy; Toivonen, Harri

    2010-01-01

    An instrument known as PANDA (Particles And Non-Destructive Analysis) for non-destructive sample analysis has been designed and built at the Finnish Radiation and Nuclear Safety Authority (STUK). In PANDA the measurement techniques and instruments designed for the basic research are applied to the analysis of environmental samples. PANDA has two vacuum chambers, one for loading samples and the other for measurements. In the measurement chamber there are two individual measurement positions. Currently the first one hosts an HPGe gamma detector and a position-sensitive alpha detector. The second measurement position is intended for precise characterization of found particles. PANDA's data are recorded in event mode and events are timestamped. In the present article the technical design of PANDA is presented in detail. In addition, its performance using depleted uranium particles and an air filter is demonstrated.

  1. Methods for collection and analysis of water samples

    USGS Publications Warehouse

    Rainwater, Frank Hays; Thatcher, Leland Lincoln

    1960-01-01

    This manual contains methods used by the U.S. Geological Survey to collect, preserve, and analyze water samples. Throughout, the emphasis is on obtaining analytical results that accurately describe the chemical composition of the water in situ. Among the topics discussed are selection of sampling sites, frequency of sampling, field equipment, preservatives and fixatives, analytical techniques of water analysis, and instruments. Seventy-seven laboratory and field procedures are given for determining fifty-three water properties.

  2. 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.

  3. Sampling and analysis of hexavalent chromium during exposure to chromic acid mist and welding fumes.

    PubMed

    Blomquist, G; Nilsson, C A; Nygren, O

    1983-12-01

    Sampling and analysis of hexavalent chromium during exposure to chromic acid mist and welding fumes. Scand j work environ & health 9 (1983) 489-495. In view of the serious health effects of hexavalent chromium, the problems involved in its sampling and analysis in workroom air have been the subject of much concern. In this paper, the stability problems arising from the reduction of hexavalent to trivalent chromium during sampling, sample storage, and analysis are discussed. Replacement of sulfuric acid by a sodium acetate buffer (pH 4) as a leaching solution prior to analysis with the diphenylcarbazide (DPC) method is suggested and is demonstrated to be necessary in order to avoid reduction. Field samples were taken from two different industrial processes-manual metal arc welding on stainless steel without shield gas and chromium plating. A comparison was made of the DPC method, acidic dissolution with atomic absorption spectrophotometric (AAS) analysis, and the carbonate method. For chromic acid mist, the DPC method and AAS analysis were shown to give the same results. In the analysis of welding fumes, the modified DPC method gave the same results as the laborious and less sensitive carbonate method.

  4. 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.

  5. 40 CFR 92.129 - Exhaust sample analysis.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... “before” span check for the next mode. (d) For sample analysis perform the following sequence: (1) Warm-up... temperature. (3) Optional: Perform a hang-up check for the HFID sampling system: (i) Zero the analyzer using... exceeds the analyzer zero response by 2 percent or more of the HFID full-scale deflection, hang-up...

  6. 40 CFR 92.129 - Exhaust sample analysis.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... “before” span check for the next mode. (d) For sample analysis perform the following sequence: (1) Warm-up... temperature. (3) Optional: Perform a hang-up check for the HFID sampling system: (i) Zero the analyzer using... exceeds the analyzer zero response by 2 percent or more of the HFID full-scale deflection, hang-up...

  7. Analysis of Iron in Lawn Fertilizer: A Sampling Study

    ERIC Educational Resources Information Center

    Jeannot, Michael A.

    2006-01-01

    An experiment is described which uses a real-world sample of lawn fertilizer in a simple exercise to illustrate problems associated with the sampling step of a chemical analysis. A mixed-particle fertilizer containing discrete particles of iron oxide (magnetite, Fe[subscript 3]O[subscript 4]) mixed with other particles provides an excellent…

  8. 40 CFR 265.92 - Sampling and analysis.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... water supply, as specified in appendix III. (2) Parameters establishing ground-water quality: (i... frequencies: (1) Samples collected to establish ground-water quality must be obtained and analyzed for the... FACILITIES Ground-Water Monitoring § 265.92 Sampling and analysis. (a) The owner or operator must obtain...

  9. 40 CFR 265.92 - Sampling and analysis.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... water supply, as specified in appendix III. (2) Parameters establishing ground-water quality: (i... frequencies: (1) Samples collected to establish ground-water quality must be obtained and analyzed for the... FACILITIES Ground-Water Monitoring § 265.92 Sampling and analysis. (a) The owner or operator must obtain...

  10. 40 CFR 265.92 - Sampling and analysis.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... water supply, as specified in appendix III. (2) Parameters establishing ground-water quality: (i... frequencies: (1) Samples collected to establish ground-water quality must be obtained and analyzed for the... FACILITIES Ground-Water Monitoring § 265.92 Sampling and analysis. (a) The owner or operator must obtain...

  11. 40 CFR 265.92 - Sampling and analysis.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... water supply, as specified in appendix III. (2) Parameters establishing ground-water quality: (i... frequencies: (1) Samples collected to establish ground-water quality must be obtained and analyzed for the... FACILITIES Ground-Water Monitoring § 265.92 Sampling and analysis. (a) The owner or operator must obtain...

  12. Sampling and Analysis Instruction for Borehole Sampling at 118-B-1 Burial Ground

    SciTech Connect

    W. S. Thompson

    2007-04-02

    The Washington Closure Hanford (WCH) Field Remediation Project has removed all of the disposed materials and contaminated soil from the 118-B-1 Burial Ground with the exception of tritium-contaminated soil that is believed to extend from the bottom of the present excavation to groundwater and is believed to contribute to tritium contamination observed at down-gradient monitoring Well 199-B8-6. This sampling and analysis instruction (SAI) provides the requirements for sample collection and laboratory analysis for characterization of the vertical distribution of tritium contamination in the vadose zone soil below the 118-B-1 Burial Ground remedial action excavation.

  13. 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.

  14. 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

  15. Modal analysis of PATHFINDER unmanned air vehicle

    SciTech Connect

    Woehrle, T.G.; Costerus, B.W.; Lee, C.L.

    1994-10-19

    An experimental modal analysis was performed on PATHFINDER, a 450-lb, 100-ft wing span, flying-wing-design aircraft powered by solar/electric motors. The aircraft was softly suspended and then excited using random input from a long-stroke shaker. Modal data was taken from 92 measurement locations on the aircraft using newly designed, lightweight, tri-axial accelerometers. A conventional PC-based data acquisition system provided data handling. Modal parameters were calculated, and animated mode shapes were produced using SMS STARStruct{trademark} Modal Analysis System software. The modal parameters will be used for validation of finite element models, optimum placement of onboard accelerometers during flight testing, and vibration isolation design of sensor platforms.

  16. 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.

  17. An Integrated Tool for System Analysis of Sample Return Vehicles

    NASA Technical Reports Server (NTRS)

    Samareh, Jamshid A.; Maddock, Robert W.; Winski, Richard G.

    2012-01-01

    The next important step in space exploration is the return of sample materials from extraterrestrial locations to Earth for analysis. Most mission concepts that return sample material to Earth share one common element: an Earth entry vehicle. The analysis and design of entry vehicles is multidisciplinary in nature, requiring the application of mass sizing, flight mechanics, aerodynamics, aerothermodynamics, thermal analysis, structural analysis, and impact analysis tools. Integration of a multidisciplinary problem is a challenging task; the execution process and data transfer among disciplines should be automated and consistent. This paper describes an integrated analysis tool for the design and sizing of an Earth entry vehicle. The current tool includes the following disciplines: mass sizing, flight mechanics, aerodynamics, aerothermodynamics, and impact analysis tools. Python and Java languages are used for integration. Results are presented and compared with the results from previous studies.

  18. An Improved, Automated Whole-Air Sampler and VOC Analysis System: Results from SONGNEX 2015

    NASA Astrophysics Data System (ADS)

    Lerner, B. M.; Gilman, J.; Tokarek, T. W.; Peischl, J.; Koss, A.; Yuan, B.; Warneke, C.; Isaacman-VanWertz, G. A.; Sueper, D.; De Gouw, J. A.; Aikin, K. C.

    2015-12-01

    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 challenging due to the requirements of short sample collection times (=10 s) to maximize spatial resolution and sampling frequency and high sensitivity (pptv) to chemically diverse hydrocarbons, halocarbons, oxygen- and nitrogen-containing VOCs. NOAA ESRL CSD has built an improved whole air sampler (iWAS) which collects compressed ambient air samples in electropolished stainless steel canisters, based on the NCAR HAIS Advanced Whole Air Sampler [Atlas and Blake]. Post-flight chemical analysis is performed with a custom-built gas chromatograph-mass spectrometer system that pre-concentrates analyte cryostatically via a Stirling cooler, an electromechanical chiller which precludes the need for liquid nitrogen to reach trapping temperatures. For the 2015 Shale Oil and Natural Gas Nexus Study (SONGNEX), CSD conducted iWAS measurements on 19 flights aboard the NOAA WP-3D aircraft between March 19th and April 27th. Nine oil and natural gas production regions were surveyed during SONGNEX and more than 1500 air samples were collected and analyzed. For the first time, we employed real-time mapping of sample collection combined with live data from fast time-response measurements (e.g. ethane) for more uniform surveying and improved target plume sampling. Automated sample handling allowed for more than 90% of iWAS canisters to be analyzed within 96 hours of collection - for the second half of the campaign improved efficiencies reduced the median sample age at analysis to 36 hours. A new chromatography peak-fitting software package was developed to minimize data reduction time by an order of magnitude without a loss of precision or accuracy. Here we report mixing ratios for aliphatic and aromatic hydrocarbons (C2-C8) along with select

  19. An Analysis of the Air Conditioning, Refrigerating and Heating Occupation.

    ERIC Educational Resources Information Center

    Frass, Melvin R.; Krause, Marvin

    The general purpose of the occupational analysis is to provide workable, basic information dealing with the many and varied duties performed in the air conditioning, refrigerating, and heating occupation. The document opens with a brief introduction followed by a job description. The bulk of the document is presented in table form. Six duties are…

  20. Cognitive Task Analysis of Prioritization in Air Traffic Control.

    ERIC Educational Resources Information Center

    Redding, Richard E.; And Others

    A cognitive task analysis was performed to analyze the key cognitive components of the en route air traffic controllers' jobs. The goals were to ascertain expert mental models and decision-making strategies and to identify important differences in controller knowledge, skills, and mental models as a function of expertise. Four groups of…