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Sample records for volatile collection analysis

  1. Volatile (As and Hg) and non-volatile (Pb and Cd) toxic heavy metals analysis in rhizome of Zingiber officinale collected from different locations of North Western Himalayas by Atomic Absorption Spectroscopy.

    Science.gov (United States)

    Gupta, S; Pandotra, P; Gupta, A P; Dhar, J K; Sharma, G; Ram, G; Husain, M K; Bedi, Y S

    2010-10-01

    Ginger is an important ingredient of spice and herbals. The monitoring of toxic heavy metals in the rhizome of ginger is important for protecting public health against the hazards of metal toxicity. The concentration of volatile and non-volatile metals (As, Hg, Pb and Cd), in the soil and rhizome of Zingiber officinale were analyzed using AAS. Soil analysis profile showed uniformity in the metal contents, in active root zone and subsoil, except mercury, which was present in higher quantity in one, out of the four sectors, of the field. The infield metal content in the soil in increasing order was, cadmium < arsenic < lead < mercury. In ginger rhizome the volatile toxic heavy metals arsenic (As) and mercury (Hg) varied from not detected to 0.13 μg/g and 0.01 to 0.42 μg/g, respectively. The non-volatile metals lead (Pb) and cadmium (Cd) ranged from 0.06 to 0.64 μg/g and 0.002 to 0.03 μg/g, respectively(.) The results illustrated the findings that soil is the major but not the only source of metal accumulation in the plants. In our study, the volatile metal content (As, Hg) was found more in rhizomes collected from Himachal Pradesh while the non-volatile metals were predominant in samples from Uttarakhand.

  2. 75 FR 74044 - Agency Information Collection Activities; Proposed Collection; Comment Request; Gasoline Volatility

    Science.gov (United States)

    2010-11-30

    ... Information Collection Activities; Proposed Collection; Comment Request; Gasoline Volatility AGENCY... entities: Entities potentially affected by this action are those who produce or import gasoline containing...: Gasoline Volatility, Reporting Requirements for Parties Which Produce of Import Gasoline Containing...

  3. Chirospecific analysis of plant volatiles

    Energy Technology Data Exchange (ETDEWEB)

    Tkachev, A V [N.N. Vorozhtsov Novosibirsk Institute of Organic Chemistry, Siberian Branch of the Russian Academy of Sciences, Novosibirsk (Russian Federation)

    2007-10-31

    Characteristic features of the analysis of plant volatiles by enantioselective gas (gas-liquid) chromatography and gas chromatography/mass spectrometry are discussed. The most recent advances in the design of enantioselective stationary phases are surveyed. Examples of the preparation of the most efficient phases based on modified cyclodextrins are given. Current knowledge on the successful analytical resolution of different types of plant volatiles (aliphatic and aromatic compounds and mono-, sesqui- and diterpene derivatives) into optical antipodes is systematically described. Chiral stationary phases used for these purposes, temperature conditions and enantiomer separation factors are summarised. Examples of the enantiomeric resolution of fragrance compounds and components of plant extracts, wines and essential oils are given.

  4. Chirospecific analysis of plant volatiles

    Science.gov (United States)

    Tkachev, A. V.

    2007-10-01

    Characteristic features of the analysis of plant volatiles by enantioselective gas (gas-liquid) chromatography and gas chromatography/mass spectrometry are discussed. The most recent advances in the design of enantioselective stationary phases are surveyed. Examples of the preparation of the most efficient phases based on modified cyclodextrins are given. Current knowledge on the successful analytical resolution of different types of plant volatiles (aliphatic and aromatic compounds and mono-, sesqui- and diterpene derivatives) into optical antipodes is systematically described. Chiral stationary phases used for these purposes, temperature conditions and enantiomer separation factors are summarised. Examples of the enantiomeric resolution of fragrance compounds and components of plant extracts, wines and essential oils are given.

  5. Linux Incident Response Volatile Data Analysis Framework

    Science.gov (United States)

    McFadden, Matthew

    2013-01-01

    Cyber incident response is an emphasized subject area in cybersecurity in information technology with increased need for the protection of data. Due to ongoing threats, cybersecurity imposes many challenges and requires new investigative response techniques. In this study a Linux Incident Response Framework is designed for collecting volatile data…

  6. Linux Incident Response Volatile Data Analysis Framework

    Science.gov (United States)

    McFadden, Matthew

    2013-01-01

    Cyber incident response is an emphasized subject area in cybersecurity in information technology with increased need for the protection of data. Due to ongoing threats, cybersecurity imposes many challenges and requires new investigative response techniques. In this study a Linux Incident Response Framework is designed for collecting volatile data…

  7. Multifractal diffusion entropy analysis on stock volatility in financial markets

    Science.gov (United States)

    Huang, Jingjing; Shang, Pengjian; Zhao, Xiaojun

    2012-11-01

    This paper introduces a generalized diffusion entropy analysis method to analyze long-range correlation then applies this method to stock volatility series. The method uses the techniques of the diffusion process and Rényi entropy to focus on the scaling behaviors of regular volatility and extreme volatility respectively in developed and emerging markets. It successfully distinguishes their differences where regular volatility exhibits long-range persistence while extreme volatility reveals anti-persistence.

  8. Volatility Spillover and Multivariate Volatility Impulse Response Analysis of GFC News Events

    NARCIS (Netherlands)

    D.E. Allen (David); M.J. McAleer (Michael); R.J. Powell (Robert); A.K. Singh (Abhay)

    2016-01-01

    textabstractThis paper applies two measures to assess spillovers across markets: the Diebold Yilmaz (2012) Spillover Index and the Hafner and Herwartz (2006) analysis of multivariate GARCH models using volatility impulse response analysis. We use two sets of data, daily realized volatility estimates

  9. Volatile organic compounds and trace metal level in some beers collected from Romanian market

    Science.gov (United States)

    Voica, Cezara; Kovacs, Melinda; Vadan, Marius

    2013-11-01

    Beer is one of the most popular beverages at worldwide level. Through this study fifteen different types of beer collected from Romanian market were analysed in order to evaluate their mineral, trace element as well the their organic content. Importance of such characterization of beer samples is supported by the fact that their chemical composition can affect both taste and stability of beer, as well the consumer health. Minerals and trace elements analysis were performed on ICP-MS while organic compounds analysis was done through GC-MS. Through ICP-MS analysis, elements as Ca, Na, K and Mg were evidenced at mgṡkg-1 order while elements as Cr, Ba, Co, Ni were detected at lower level. After GC-MS analysis the major volatile compounds that were detected belong to alcohols namely ethanol, propanol, isobutanol, isoamyl alcohol and linalool. Selected fatty acids and esters were evidenced also in the studied beer samples.

  10. Detection of mastitis pathogens by analysis of volatile bacterial metabolites

    NARCIS (Netherlands)

    Hettinga, K.A.; Valenberg, van H.J.F.; Lam, T.J.G.M.; Hooijdonk, van A.C.M.

    2008-01-01

    The ability to detect mastitis pathogens based on their volatile metabolites was studied. Milk samples from cows with clinical mastitis, caused by Staphylococcus aureus, coagulase-negative staphylococci, Streptococcus uberis, Streptococcus dysgalactiae, and Escherichia coli were collected. In

  11. An Intelligent Analysis Model for Multisource Volatile Memory

    Directory of Open Access Journals (Sweden)

    Xiaolu Zhang

    2013-09-01

    Full Text Available For the rapidly development of network and distributed computing environment, it make researchers harder to do analysis examines only from one or few pieces of data source in persistent data-oriented approaches, so as the volatile memory analysis either. Therefore, mass data automatically analysis and action modeling needs to be considered for reporting entire network attack process. To model multiple volatile data sources situation can help understand and describe both thinking process of investigator and possible action step for attacker. This paper presents a Game model for multisource volatile data and applies it to main memory images analysis with the definition of space-time feature for volatile element information. Abstract modeling allows the lessons gleaned in performing intelligent analysis, evidence filing and automating presentation. Finally, a test demo based on the model is also present to illustrate the whole procedure

  12. Application of head-space solid-phase microextraction for the analysis of volatile metabolites emitted by Penicillium species

    DEFF Research Database (Denmark)

    Nilsson, Torben; Larsen, Thomas Ostenfeld; Montanarella, Luca

    1996-01-01

    Head-space solid-phase microextraction (HS-SPME) has been used to collect volatile organic compounds (VOCs) emitted from fungi of the genus Penicillium. Gas chromatography combined with mass spectrometry (GC-MS) was employed for the analysis of the profiles of volatile metabolites characteristic ...

  13. Volatile Organic Compound Analysis in Istanbul

    Science.gov (United States)

    Ćapraz, Ö.; Deniz, A.; Öztürk, A.; Incecik, S.; Toros, H.; Coşkun, M.

    2012-04-01

    Volatile Organic Compound Analysis in Istanbul Ö. Çapraz1, A. Deniz1,3, A. Ozturk2, S. Incecik1, H. Toros1 and, M. Coskun1 (1) Istanbul Technical University, Faculty of Aeronautics and Astronautics, Department of Meteorology, 34469, Maslak, Istanbul, Turkey. (2) Istanbul Technical University, Faculty of Chemical and Metallurgical, Chemical Engineering, 34469, Maslak, Istanbul, Turkey. (3) Marmara Clean Air Center, Ministry of Environment and Urbanization, Nişantaşı, 34365, İstanbul, Turkey. One of the major problems of megacities is air pollution. Therefore, investigations of air quality are increasing and supported by many institutions in recent years. Air pollution in Istanbul contains many components that originate from a wide range of industrial, heating, motor vehicle, and natural emissions sources. VOC, originating mainly from automobile exhaust, secondhand smoke and building materials, are one of these compounds containing some thousands of chemicals. In spite of the risks to human health, relatively little is known about the levels of VOC in Istanbul. In this study, ambient air quality measurements of 32 VOCs including hydrocarbons, halogenated hydrocarbons and carbonyls were conducted in Kağıthane (Golden Horn) region in Istanbul during the winter season of 2011 in order to develop the necessary scientific framework for the subsequent developments. Kağıthane creek valley is the source part of the Golden Horn and one of the most polluted locations in Istanbul due to its topographical form and pollutant sources in the region. In this valley, horizontal and vertical atmospheric motions are very weak. The target compounds most commonly found were benzene, toluene, xylene and ethyl benzene. Concentrations of total hydrocarbons ranged between 1.0 and 10.0 parts per billion, by volume (ppbv). Ambient air levels of halogenated hydrocarbons appeared to exhibit unique spatial variations and no single factor seemed to explain trends for this group of

  14. Multivariate Volatility Impulse Response Analysis of GFC News Events

    NARCIS (Netherlands)

    D.E. Allen (David); M.J. McAleer (Michael); R.J. Powell (Robert); A.K. Singh (Abhay)

    2015-01-01

    textabstractThis paper applies the Hafner and Herwartz (2006) (hereafter HH) approach to the analysis of multivariate GARCH models using volatility impulse response analysis. The data set features ten years of daily returns series for the New York Stock Exchange Index and the FTSE 100 index from the

  15. Multivariate Volatility Impulse Response Analysis of GFC News Events

    NARCIS (Netherlands)

    D.E. Allen (David); M.J. McAleer (Michael); R.J. Powell (Robert)

    2015-01-01

    markdownabstract__Abstract__ This paper applies the Hafner and Herwartz (2006) (hereafter HH) approach to the analysis of multivariate GARCH models using volatility impulse response analysis. The data set features ten years of daily returns series for the New York Stock Exchange Index and the FTSE

  16. Multivariate Volatility Impulse Response Analysis of GFC News Events

    NARCIS (Netherlands)

    D.E. Allen (David); M.J. McAleer (Michael); R.J. Powell (Robert)

    2015-01-01

    markdownabstract__Abstract__ This paper applies the Hafner and Herwartz (2006) (hereafter HH) approach to the analysis of multivariate GARCH models using volatility impulse response analysis. The data set features ten years of daily returns series for the New York Stock Exchange Index and the

  17. Multivariate Volatility Impulse Response Analysis of GFC News Events

    NARCIS (Netherlands)

    D.E. Allen (David); M.J. McAleer (Michael); R.J. Powell (Robert); A.K. Singh (Abhay)

    2015-01-01

    textabstractThis paper applies the Hafner and Herwartz (2006) (hereafter HH) approach to the analysis of multivariate GARCH models using volatility impulse response analysis. The data set features ten years of daily returns series for the New York Stock Exchange Index and the FTSE 100 index from the

  18. DOES ENERGY CONSUMPTION VOLATILITY AFFECT REAL GDP VOLATILITY? AN EMPIRICAL ANALYSIS FOR THE UK

    Directory of Open Access Journals (Sweden)

    Abdul Rashid

    2013-10-01

    Full Text Available This paper empirically examines the relation between energy consumption volatility and unpredictable variations in real gross domestic product (GDP in the UK. Estimating the Markov switching ARCH model we find a significant regime switching in the behavior of both energy consumption and GDP volatility. The results from the Markov regime-switching model show that the variability of energy consumption has a significant role to play in determining the behavior of GDP volatilities. Moreover, the results suggest that the impacts of unpredictable variations in energy consumption on GDP volatility are asymmetric, depending on the intensity of volatility. In particular, we find that while there is no significant contemporaneous relationship between energy consumption volatility and GDP volatility in the first (low-volatility regime, GDP volatility is significantly positively related to the volatility of energy utilization in the second (high-volatility regime.

  19. Volatile compounds formation in alcoholic fermentation from grapes collected at 2 maturation stages: influence of nitrogen compounds and grape variety.

    Science.gov (United States)

    Martínez-Gil, Ana M; Garde-Cerdán, Teresa; Lorenzo, Cándida; Lara, José Félix; Pardo, Francisco; Salinas, M Rosario

    2012-01-01

    The aim of this work was to study the influence of nitrogen compounds on the formation of volatile compounds during the alcoholic fermentation carried out with 4 nonaromatic grape varieties collected at 2 different maturation stages. To do this, Monastrell, Merlot, Syrah, and Petit Verdot grapes were collected 1 wk before harvest and at harvest. Then, the musts were inoculated with the same Saccharomyces cerevisiae yeast strain and were fermented in the same winemaking conditions. Amino acids that showed the highest and the lowest concentration in the must were the same, regardless of the grape variety and maturation stage. Moreover, the consumption of amino acids during the fermentation increased with their concentration in the must. The formation of volatile compounds was not nitrogen composition dependent. However, the concentration of amino acids in the must from grapes collected 1 wk before harvest can be used as a parameter to estimate the concentration of esters in wines from grapes collected at harvest and therefore to have more information to know the grape oenological capacity. Application of principal components analysis (PCA) confirmed the possibility to estimate the concentration of esters in the wines with the concentration of nitrogen compounds in the must.

  20. Volatile Analysis by Pyrolysis of Regolith for Planetary Resource Exploration

    Science.gov (United States)

    Glavin, Daniel P.; Malespin, Charles; ten Kate, Inge L.; Getty, Stephanie A.; Holmes, Vincent E.; Mumm, Erik; Franz, Heather B.; Noreiga, Marvin; Dobson, Nick; Southard, Adrian E.; hide

    2012-01-01

    The extraction and identification of volatile resources that could be utilized by humans including water, oxygen, noble gases, and hydrocarbons on the Moon, Mars, and small planetary bodies will be critical for future long-term human exploration of these objects. Vacuum pyrolysis at elevated temperatures has been shown to be an efficient way to release volatiles trapped inside solid samples. In order to maximize the extraction of volatiles, including oxygen and noble gases from the breakdown of minerals, a pyrolysis temperature of 1400 C or higher is required, which greatly exceeds the maximum temperatures of current state-of-the-art flight pyrolysis instruments. Here we report on the recent optimization and field testing results of a high temperature pyrolysis oven and sample manipulation system coupled to a mass spectrometer instrument called Volatile Analysis by Pyrolysis of Regolith (VAPoR). VAPoR is capable of heating solid samples under vacuum to temperatures above 1300 C and determining the composition of volatiles released as a function of temperature.

  1. Modeling daily realized futures volatility with singular spectrum analysis

    Science.gov (United States)

    Thomakos, Dimitrios D.; Wang, Tao; Wille, Luc T.

    2002-09-01

    Using singular spectrum analysis (SSA), we model the realized volatility and logarithmic standard deviations of two important futures return series. The realized volatility and logarithmic standard deviations are constructed following the methodology of Andersen et al. [J. Am. Stat. Ass. 96 (2001) 42-55] using intra-day transaction data. We find that SSA decomposes the volatility series quite well and effectively captures both the market trend (accounting for about 34-38% of the total variance in the series) and, more importantly, a number of underlying market periodicities. Reliable identification of any periodicities is extremely important for options pricing and risk management and we believe that SSA can be a useful addition to the financial practitioners’ toolbox.

  2. Analysis of volatile compounds from Iberian hams: a review

    Directory of Open Access Journals (Sweden)

    Narváez-Rivas, M.

    2012-10-01

    Full Text Available This article provides information on the study of the volatile compounds in raw and dry-cured Iberian hams. Different volatile compounds are identified and studies carried out by different authors are presented. This article reviews the analytical methods that have been used to determine the different volatiles of these samples. Furthermore, all volatile compounds identified (a total of 411 volatiles have been collected in several tables according to different series of compounds: hydrocarbons, aldehydes, ketones, alcohols, esters and ethers, lactones, terpenes and chloride compounds, nitrogenous compounds, sulfur compounds and carboxylic acids. This review can be useful in subsequent research due to the complexity of the study.

    En este artículo se proporciona información sobre el estudio de los compuestos volátiles del jamón ibérico tanto fresco como curado. Se presentan los diferentes compuestos volátiles identificados por distintos autores. Además, se evalúan los métodos analíticos que han sido utilizados para determinar dichos compuestos volátiles en este tipo de muestras. Todos los compuestos identificados y descritos en esta revisión (un total de 411 compuestos volátiles han sido agrupados en diversas tablas de acuerdo a las diferentes familias a que pertenecen: hidrocarburos, aldehídos, cetonas, alcoholes, ésteres y éteres, lactonas, terpenos, compuestos halogenados, compuestos nitrogenados, compuestos de azufre y ácidos carboxílicos. Debido a la complejidad de este estudio, la presente revisión puede ser muy útil en investigaciones posteriores.

  3. New graphene fiber coating for volatile organic compounds analysis.

    Science.gov (United States)

    Zhang, GuoJuan; Guo, XiaoXi; Wang, ShuLing; Wang, XueLan; Zhou, YanPing; Xu, Hui

    2014-10-15

    In the work, a novel graphene-based solid phase microextraction-gas chromatography/mass spectrometry method was developed for the analysis of trace amount of volatile organic compounds in human exhaled breath vapor. The graphene fiber coating was prepared by a one-step hydrothermal reduction reaction. The fiber with porous and wrinkled structure exhibited excellent extraction efficiency toward eight studied volatile organic compounds (two n-alkanes, five n-aldehydes and one aromatic compound). Meanwhile, remarkable thermal and mechanical stability, long lifespan and low cost were also obtained for the fiber. Under the optimal conditions, the developed method provided low limits of detection (1.0-4.5ngL(-1)), satisfactory reproducibility (3.8-13.8%) and acceptable recoveries (93-122%). The method was applied successfully to the analysis of breath samples of lung cancer patients and healthy individuals. The unique advantage of this approach includes simple setup, non-invasive analysis, cost-efficient and sufficient sensitivity. The proposed method supply us a new possibility to monitor volatile organic compounds in human exhaled breath samples.

  4. Comparison of two headspace sampling techniques for the analysis of off-flavour volatiles from oat based products.

    Science.gov (United States)

    Cognat, Claudine; Shepherd, Tom; Verrall, Susan R; Stewart, Derek

    2012-10-01

    Two different headspace sampling techniques were compared for analysis of aroma volatiles from freshly produced and aged plain oatcakes. Solid phase microextraction (SPME) using a Carboxen-Polydimethylsiloxane (PDMS) fibre and entrainment on Tenax TA within an adsorbent tube were used for collection of volatiles. The effects of variation in the sampling method were also considered using SPME. The data obtained using both techniques were processed by multivariate statistical analysis (PCA). Both techniques showed similar capacities to discriminate between the samples at different ages. Discrimination between fresh and rancid samples could be made on the basis of changes in the relative abundances of 14-15 of the constituents in the volatile profiles. A significant effect on the detection level of volatile compounds was observed when samples were crushed and analysed by SPME-GC-MS, in comparison to undisturbed product. The applicability and cost effectiveness of both methods were considered. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. Does Energy Consumption Volatility Affect Real GDP Volatility? An Empirical Analysis for the UK

    OpenAIRE

    Abdul Rashid; Ozge Kandemir Kocaaslan

    2013-01-01

    This paper empirically examines the relation between energy consumption volatility and unpredictable variations in real gross domestic product (GDP) in the UK. Estimating the Markov switching ARCH model we find a significant regime switching in the behavior of both energy consumption and GDP volatility. The results from the Markov regime-switching model show that the variability of energy consumption has a significant role to play in determining the behavior of GDP volatilities. Moreover, the...

  6. HS-SPME-GC-MS ANALYSIS OF VOLATILE AND SEMI-VOLATILE COMPOUNDS FROM DRIED LEAVES OF Mikania glomerata Sprengel

    Directory of Open Access Journals (Sweden)

    Esmeraldo A. Cappelaro

    2015-03-01

    Full Text Available This paper reports on the identification of volatile and semi-volatile compounds and a comparison of the chromatographic profiles obtained by Headspace Solid-Phase Microextraction/Gas Chromatography with Mass Spectrometry detection (HS-SPME-GC-MS of dried leaves of Mikania glomerata Sprengel (Asteraceae, also known as 'guaco.' Three different types of commercial SPME fibers were tested: polydimethylsiloxane (PDMS, polydimethylsiloxane/divinylbenzene (PDMS/DVB and polyacrylate (PA. Fifty-nine compounds were fully identified by HS-SPME-HRGC-MS, including coumarin, a marker for the quality control of guaco-based phytomedicines; most of the other identified compounds were mono- and sesquiterpenes. PA fibers performed better in the analysis of coumarin, while PDMS-DVB proved to be the best choice for a general and non-selective analysis of volatile and semi-volatile guaco-based compounds. The SPME method is faster and requires a smaller sample than conventional hydrodistillation of essential oils, providing a general overview of the volatile and semi-volatile compounds of M. glomerata.

  7. [Behavioral response of Anopheles albimanus to volatile compounds collected inside houses from the south of Chiapas, Mexico].

    Science.gov (United States)

    Ríos-Delgado, Silvany Mayoly; Rodríguez-Ramírez, Américo David; Cruz-López, Leopoldo; Escobar-Pérez, Luis Alonso; Aburto-Juárez, Ma de Lourdes; Torres-Estrada, José Luis

    2008-01-01

    To determine effects of volatile compounds in homes on the behavioral response of Anopheles albimanus. The study was conducted in January 2006, in the village of Nueva Independencia village, Suchiate, Chiapas. Volatile compounds were collected inside homes and the extracts were tested on unfed females in a Y-olfactometer. Extracts were analyzed in a gas chromatography-mass spectrometry system (GC-MS). Twenty eight extracts were obtained, twelve presented attraction and two repellency responses. GC-MS analyses of the extracts indicated variation in the volatile compound present in the extracts, but could not associated specific compounds with any particular effect. Within homes, volatiles presented attraction and repellency responses to An. albimanus. A definate pattern concerning the presence of a characteristic chemical compound and the observed response was not found.

  8. Aerogel volatiles concentrator and analyzer (AVCA) - Collection and concentration of trace volatile organics in aerogel for spectroscopic detection

    Science.gov (United States)

    Tsapin, A.; Jones, S.; Petkov, M.; Borchardt, D.; Anderson, M.

    2017-03-01

    A study was conducted to determine the efficacy of using silica aerogel to collect and concentrate ambient trace organics for spectroscopic analysis. Silica aerogel was exposed to atmospheres containing trace amounts of polycyclic aromatic and aliphatic hydrocarbons. The organics present were concentrated in the aerogels by factors varying from 10 to more than 1000 over the levels found in the atmospheres, depending on the specific organic present. Since silica aerogel is transparent over a wide range of optical and near infrared wavelengths, UV-induced fluorescence, Raman and infrared spectroscopies were used to detect and identify the organics collected by the aerogel. Measurements were conducted to determine the sensitivity of these spectroscopic methods for determining organics concentrated by aerogels and the effectiveness of this method for identifying systems containing multiple organic species. Polycyclic aromatic hydrocarbons (PAHs) were added to simulated Mars regolith and then vaporized by modest heating in the presence of aerogel. The aerogels adsorbed and concentrated the PAHs, which were detected by induced fluorescence and Raman and FTIR spectroscopies.

  9. Lunar Advanced Volatile Analysis Subsystem: Pressure Transducer Trade Study

    Science.gov (United States)

    Kang, Edward Shinuk

    2017-01-01

    In Situ Resource Utilization (ISRU) is a key factor in paving the way for the future of human space exploration. The ability to harvest resources on foreign astronomical objects to produce consumables and propellant offers potential reduction in mission cost and risk. Through previous missions, the existence of water ice at the poles of the moon has been identified, however the feasibility of water extraction for resources remains unanswered. The Resource Prospector (RP) mission is currently in development to provide ground truth, and will enable us to characterize the distribution of water at one of the lunar poles. Regolith & Environment Science and Oxygen & Lunar Volatile Extraction (RESOLVE) is the primary payload on RP that will be used in conjunction with a rover. RESOLVE contains multiple instruments for systematically identifying the presence of water. The main process involves the use of two systems within RESOLVE: the Oxygen Volatile Extraction Node (OVEN) and Lunar Advanced Volatile Analysis (LAVA). Within the LAVA subsystem, there are multiple calculations that depend on accurate pressure readings. One of the most important instances where pressure transducers (PT) are used is for calculating the number of moles in a gas transfer from the OVEN subsystem. As a critical component of the main process, a mixture of custom and commercial off the shelf (COTS) PTs are currently being tested in the expected operating environment to eventually down select an option for integrated testing in the LAVA engineering test unit (ETU).

  10. Collective Analysis of Qualitative Data

    DEFF Research Database (Denmark)

    2014-01-01

    What. Many students and practitioners do not know how to systematically process qualitative data once it is gathered—at least not as a collective effort. This chapter presents two workshop techniques, affinity diagramming and diagnostic mapping, that support collective analysis of large amounts...... of qualitative data. Affinity diagramming is used to make collective analysis and interpretations of qualitative data to identify core problems that need to be addressed in the design process. Diagnostic mapping supports collective interpretation and description of these problems and how to intervene in them. We...... explain the techniques through a case where they were used to analyze why a new elec- tronic medical record system introduced life-threatening situations for patients. Why. Collective analyses offer all participants a voice, visualize their contributions, combine different actors’ perspectives, and anchor...

  11. 不同采收期栽培宽叶羌活挥发性成分的研究%Comparison Analysis of Contents and Constituents of Volatile Oils Extracted from Cultivated Notopterygium forbesii H.Boiss Collected in Different Months

    Institute of Scientific and Technical Information of China (English)

    李春丽; 周玉碧; 周国英; 徐文华; 杨路存

    2012-01-01

    采用水蒸气蒸馏法提取不同采收时间(5、6、7、8和9月)栽培宽叶羌活药材中的挥发油,测定其含量;通过GC-MS对挥发油成分进行了分析鉴定,并采用面积归一化法计算各组分的相对含量.实验结果表明,不同采收时间,栽培宽叶羌活挥发油含量存在差异,以8月份采收的药材挥发油含量最高;挥发油经GC-MS分析,共鉴定出39个化合物,有31种共有成分;对共有组分进行主成分分析显示,香桧烯、a-蒎烯、莰烯、β-蒎烯、γ-萜品烯、乙酸龙脑酯、α-红没药醇等15种成分可作为挥发油季节变化的特征组分.不同季节采集的羌活生药材,其挥发油含量和成分具有一定的差别,在一定程度上反映了其药用价值的微妙差异,可为羌活药材药理药用价值的进一步开发利用提供一定的参考.%To determine the contents and constituents of volatile oils extracted from cultivated Notopterygium forbesii H. Boiss vegetated in different months. Analyzed their seasonal dynamics and provided experiment foundation for reasonable utilization of Rhizoma et Radix Notopteiygii. Volatile oils were extracted by steam distillation. The chemical constituents were separated and identified by gas chromatography-mass spectrometer (GC-MS). The relative content of each component was determined by area normalization. The difference of volatile oil contents was significant at the 0. 01 level between different samples. The content was highest in the sample collected in August,and lowest in the sample vegetated in May. Thirty nine constituents were identified by GC-MS analysis .and there were thirty one same compounds in the five samples. The principal components analysis of SPSS was applied to the study of characteristic compounds and separated 15 kinds of compounds as characteristic constituents of volatile oil extracted from cultivated N. forbesii H. Boiss. vegetated in different months. The contents and constituents of

  12. Stochastic Volatility Model and Technical Analysis of Stock Price

    Institute of Scientific and Technical Information of China (English)

    Wei LIU; Wei An ZHENG

    2011-01-01

    In the stock market, some popular technical analysis indicators (e.g. Bollinger Bands, RSI,ROC, ...) are widely used by traders. They use the daily (hourly, weekly, ...) stock prices as samples of certain statistics and use the observed relative frequency to show the validity of those well-knownindicators. However, those samples are not independent, so the classical sample survey theory does not apply. In earlier research, we discussed the law of large numbers related to those observations when one assumes Black-Scholes' stock price model. In this paper, we extend the above results to the more popular stochastic volatility model.

  13. [Analysis of human tissue samples for volatile fire accelerants].

    Science.gov (United States)

    Treibs, Rudolf

    2014-01-01

    In police investigations of fires, the cause of a fire and the fire debris analysis regarding traces of fire accelerants are important aspects for forensic scientists. Established analytical procedures were recently applied to the remains of fire victims. When examining lung tissue samples, vapors inhaled from volatile ignitable liquids could be identified and differentiated from products of pyrolysis caused by the fire. In addition to the medico-legal results this evidence allowed to draw conclusions as to whether the fire victim was still alive when the fire started.

  14. Chemical composition and non-volatile components of three wild edible mushrooms collected from northwest Tunisia

    Directory of Open Access Journals (Sweden)

    ibtissem Kacem Jedidi

    2016-04-01

    Full Text Available In Tunisia, many people collect wild edible mushrooms as pickers for their own consumption. The present work aims at contributing to the determination of the chemical composition, non volatile components content (soluble sugars, free amino acids and minerals and trace elements of three popular Tunisian wild edible mushrooms species collected from the northwest of Tunisia (Agaricus campestris, Boletus edulis and Cantharellus cibarius.All investigated mushrooms revealed that these species are rich sources of proteins (123.70 – 374.10 g kg-1 dry weight (DW and carbohydrates (403.3 – 722.40 g kg-1 DW, and low content of fat (28.2 – 39.9 g kg-1 DW; the highest energetic contribution was guaranteed by C. cibarius (1542.71 kJ / 100 g. A. compestris (33.14 mg/g DW showed the highest concentration of essential amino acids. The composition in individual sugars was also determined, mannitol and trehalose being the most abundant sugars. C. cibarius revealed the highest concentrations of carbohydrates (722.4 g kg-1 DW and A. compestris the lowest concentration (403.3 g kg-1 DW. Potassium (K and sodium (Na are the most abundant minerals in analyzed samples (A. compestris showed the highest concentrations of K and Na, 49141.44 and 9263.886 µg/g DW respectively.

  15. Providing a Foundation for Analysis of Volatile Data Stores

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    Timothy Vidas

    2007-09-01

    Full Text Available Current threats against typical computer systems demonstrate a need for forensic analysis of memory-resident data in addition to the conventional static analysis common today.  Certain attacks and types of malware exist solely in memory and leave little or no evidentiary information on nonvolatile stores such as a hard disk drive.  The desire to preserve system state at the time of response may even warrant memory acquisition independent of perceived threats and the ability to analyze the acquired duplicate. Tools capable of duplicating various types of volatile data stores are becoming widely available.  Once the data store has been duplicated, current forensic procedures have no method for extrapolating further useful information from the duplicate.  This paper is focused on providing the groundwork for performing forensic investigations on the data that is typically stored in a volatile data store, such as system RAM.It is intended that, when combined with good acquisition techniques, it will be shown that it is possible to obtain more post incident response information along with less impact to potential evidence when compared to typical incident response procedures. 

  16. Collection and identification of human remains volatiles by non-contact, dynamic airflow sampling and SPME-GC/MS using various sorbent materials.

    Science.gov (United States)

    DeGreeff, Lauryn E; Furton, Kenneth G

    2011-09-01

    Human remains detection canines are used in locating deceased humans in diverse scenarios and environments based on odor produced during the decay process of the human body. It has been established that human remains detection canines are capable of locating human remains specifically, as opposed to living humans or animal remains, thus suggesting a difference in odor between the different sources. This work explores the collection and determination of such odors using a dynamic headspace concentration device. The airflow rate and three sorbent materials-Dukal cotton gauze, Johnson & Johnson cotton-blend gauze, and polyester material-used for odor collection were evaluated using standard compounds. It was determined that higher airflow rates and openly woven material, e.g., Dukal cotton gauze, yielded significantly less total volatile compounds due to compound breakthrough through the sorbent material. Collection from polymer- and cellulose-based materials demonstrated that the molecular backbone of the material is a factor in compound collection as well. Volatiles, including cyclic and straight-chain hydrocarbons, organic acids, sulfides, aldehydes, ketones, and alcohols, were collected from a population of 27 deceased bodies from two collection locations. The common compounds between the subjects were compared and the odor profiles were determined. These odor profiles were compared with those of animal remains and living human subjects collected in the same manner. Principal component analysis showed that the odor profiles of the three sample types were distinct.

  17. Sapphire: a better material for atomization and in situ collection of silver volatile species for atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Musil, Stanislav, E-mail: stanomusil@biomed.cas.cz; Matoušek, Tomáš; Dědina, Jiří

    2015-06-01

    Sapphire is presented as a high temperature and corrosion resistant material of an optical tube of an atomizer for volatile species of Ag generated by the reaction with NaBH{sub 4}. The modular atomizer design was employed which allowed to carry out the measurements in two modes: (i) on-line atomization and (ii) in situ collection (directly in the optical tube) by means of excess of O{sub 2} over H{sub 2} in the carrier gas during the trapping step and vice versa in the volatilization step. In comparison with quartz atomizers, the sapphire tube atomizer provides a significantly increased atomizer lifetime as well as substantially improved repeatability of the Ag in situ collection signals shapes. In situ collection of Ag in the sapphire tube atomizer was highly efficient (> 90%). Limit of detection in the on-line atomization mode and in situ collection mode, respectively, was 1.2 ng ml{sup −1} and 0.15 ng ml{sup −1}. - Highlights: • Sapphire was tested as a new material of an atomizer tube for Ag volatile species. • Two measurement modes were investigated: on-line atomization and in situ collection. • In situ collection of Ag was highly efficient (> 90%) with LOD of 0.15 ng ml{sup −1}. • No devitrification of the sapphire tube observed in the course of several months.

  18. Study on Honey Quality Evaluation and Detection of Adulteration by Analysis of Volatile Compounds

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    Kružík Vojtěch

    2017-06-01

    Full Text Available Fast evaluation of honey quality is a topical and significant problem of the food industry, bee keepers and consumers. In this work, 22 samples of commercially available honey aromas (with methyl and ethyl esters of phenylacetic acid predominated, 13 samples of authentic honey collected directly from bee keepers (characterised by high content of benzaldehyde, 2-phenylethanol, hotrienol and 2-phenylacetaldehyde and 63 honeys purchased from an outdoor market were evaluated based on volatiles profiles determined through solid-phase microextraction coupled with gas chromatography-mass spectrometry (SPME-GC/MS and then suspicious samples were identified. The results were statistically processed and compared with results of a sensory analysis. Six honeys, which differed significantly in volatiles profiles (outliers detected by Factor Analysis, selected volatile substance representation (furan-2-carbaldehyde, 1,4-dimethylpyrazole, benzaldehyde, 2-phenylacetaldehyde and honey aroma intensity and pleasantness were subjected to targeted analyses (i.e. determination of 5-(hydroxymethyl-2-furaldehyde, diastase activity, unauthorized additive presence. Four of these suspicious samples were found to have high content of 5-(hydroxymethyl-2-furaldehyde (more than 40 mg/kg, three honeys had low values for diastase activity (less than 8 and three samples positive for triacetin addition. The fact that all these samples revealed a breach of least one of the selected quality parameters defined by the Codex Alimentarius standard proved the proposed methodology to be a useful tool for fast quality evaluation of honey.

  19. Molecular analysis of volatile metabolites released specifically by staphylococcus aureus and pseudomonas aeruginosa

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    Filipiak Wojciech

    2012-06-01

    Full Text Available Abstract Background The routinely used microbiological diagnosis of ventilator associated pneumonia (VAP is time consuming and often requires invasive methods for collection of human specimens (e.g. bronchoscopy. Therefore, it is of utmost interest to develop a non-invasive method for the early detection of bacterial infection in ventilated patients, preferably allowing the identification of the specific pathogens. The present work is an attempt to identify pathogen-derived volatile biomarkers in breath that can be used for early and non- invasive diagnosis of ventilator associated pneumonia (VAP. For this purpose, in vitro experiments with bacteria most frequently found in VAP patients, i.e. Staphylococcus aureus and Pseudomonas aeruginosa, were performed to investigate the release or consumption of volatile organic compounds (VOCs. Results Headspace samples were collected and preconcentrated on multibed sorption tubes at different time points and subsequently analyzed with gas chromatography mass spectrometry (GC-MS. As many as 32 and 37 volatile metabolites were released by S. aureus and P. aeruginosa, respectively. Distinct differences in the bacteria-specific VOC profiles were found, especially with regard to aldehydes (e.g. acetaldehyde, 3-methylbutanal, which were taken up only by P. aeruginosa but released by S. aureus. Differences in concentration profiles were also found for acids (e.g. isovaleric acid, ketones (e.g. acetoin, 2-nonanone, hydrocarbons (e.g. 2-butene, 1,10-undecadiene, alcohols (e.g. 2-methyl-1-propanol, 2-butanol, esters (e.g. ethyl formate, methyl 2-methylbutyrate, volatile sulfur compounds (VSCs, e.g. dimethylsulfide and volatile nitrogen compounds (VNCs, e.g. 3-methylpyrrole. Importantly, a significant VOC release was found already 1.5 hours after culture start, corresponding to cell numbers of ~8*106 [CFUs/ml]. Conclusions The results obtained provide strong evidence that the detection and perhaps even

  20. Windows Volatile Memory Forensics Based on Correlation Analysis

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    Xiaolu Zhang

    2014-03-01

    Full Text Available In this paper, we present an integrated memory forensic solution for multiple Windows memory images. By calculation, the method can find out the correlation degree among the processes of volatile memory images and the hidden clues behind the events of computers, which is usually difficult to be obtained and easily ignored by analyzing one single memory image and forensic investigators. In order to test the validity, we performed an experiment based on two hosts' memory image which contains criminal incidents. According to the experimental result, we find that the event chains reconstructed by our method are similar to the actual actions in the criminal scene. Investigators can review the digital crime scenario which is contained in the data set by analyzing the experimental results. This paper is aimed at finding the valid actions with illegal attempt and making the memory analysis not to be utterly dependent on the operating system and relevant experts.

  1. Analysis of volatiles in Pinotage wines by stir bar sorptive extraction and chemometric profiling.

    Science.gov (United States)

    Weldegergis, Berhane T; Crouch, Andrew M

    2008-11-12

    A fast, simple, cost-effective, and reliable method based on stir bar sorptive extraction (SBSE) in the headspace mode was used for the analysis of 39 volatile components in Pinotage wines. The method was sensitive, with LODs ranging from 50.0 pg/L to 281 ng/L and LOQs between 180 pg/L and 938 ng/L. Precision was between 6 and 20%. The intermediate precision was within the acceptable range. Moreover, good calibration curves with R(2) > 0.99 for all compounds were achieved. The method was successfully applied for the analysis of 87 young Pinotage wines of vintages 2005 and 2006 collected from various South African regions. To characterize the results based on vintage and origin, the obtained concentrations of the compounds were subjected to chemometric analysis. Exploratory factor analysis (FA), principal component analysis (PCA), and analysis of variance (one-way ANOVA) were consecutively done. The chemometrics approach revealed a reasonable correlation among the volatile components of these wines, as well as with respect to their year of production.

  2. A rapid column technique for trapping and collecting of volatile fungal hydrocarbons and hydrocarbon derivatives.

    Science.gov (United States)

    Booth, Eric; Strobel, Gary; Knighton, Berk; Sears, Joe; Geary, Brad; Avci, Recep

    2011-10-01

    A custom-made stainless steel column was designed to contain various materials that would trap the hydrocarbons and hydrocarbon derivatives during the processes of fungal fermentation ultimately yielding preparative amounts of volatile organic substances (VOCs). Trapping materials tested in the column were Carbotrap materials A and B (Supelco) as well as bentonite-shale from the oil bearing areas of Eastern Montana, the former allowed for the effective and efficient trapping of VOCs from purged cultures of Hypoxylon sp. Trapping efficiencies of various materials were measured by both gravimetric as well as proton transfer reaction mass spectroscopy with the Carbotraps A and B being 99% efficient when tested with known amounts of 1,8-cineole. Trapped fungal VOCs could effectively be removed and recovered via controlled heating of the stainless steel column followed by passage of the gases through a liquid nitrogen trap at a recovery rate of ca 65-70%. This method provides for the recovery of mg quantities of compounds normally present in the gas phase that may be needed for spectroscopy, bioassays and further separation and analysis and may have wide applicability for many other biological systems involving VOCs. Other available Carbotraps could be used for other applications.

  3. Measuring the atmospheric organic aerosol volatility distribution: a theoretical analysis

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    E. Karnezi

    2014-01-01

    Full Text Available Organic compounds represent a significant fraction of submicrometer atmospheric aerosol mass. Even if most of these compounds are semi-volatile in atmospheric concentrations, the ambient organic aerosol volatility is quite uncertain. The most common volatility measurement method relies on the use of a thermodenuder (TD. The aerosol passes through a heated tube where its more volatile components evaporate leaving the less volatile behind in the particulate phase. The typical result of a~thermodenuder measurement is the mass fraction remaining (MFR, which depends among other factors on the organic aerosol (OA vaporization enthalpy and the accommodation coefficient. We use a new method combining forward modeling, introduction of "experimental" error and inverse modeling with error minimization for the interpretation of TD measurements. The OA volatility distribution, its effective vaporization enthalpy, the mass accommodation coefficient and the corresponding uncertainty ranges are calculated. Our results indicate that existing TD-based approaches quite often cannot estimate reliably the OA volatility distribution, leading to large uncertainties, since there are many different combinations of the three properties that can lead to similar thermograms. We propose an improved experimental approach combining TD and isothermal dilution measurements. We evaluate this experimental approach using the same model and show that it is suitable for studies of OA volatility in the lab and the field.

  4. Volatile Metabolites

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    Daryl D. Rowan

    2011-11-01

    Full Text Available Volatile organic compounds (volatiles comprise a chemically diverse class of low molecular weight organic compounds having an appreciable vapor pressure under ambient conditions. Volatiles produced by plants attract pollinators and seed dispersers, and provide defense against pests and pathogens. For insects, volatiles may act as pheromones directing social behavior or as cues for finding hosts or prey. For humans, volatiles are important as flavorants and as possible disease biomarkers. The marine environment is also a major source of halogenated and sulfur-containing volatiles which participate in the global cycling of these elements. While volatile analysis commonly measures a rather restricted set of analytes, the diverse and extreme physical properties of volatiles provide unique analytical challenges. Volatiles constitute only a small proportion of the total number of metabolites produced by living organisms, however, because of their roles as signaling molecules (semiochemicals both within and between organisms, accurately measuring and determining the roles of these compounds is crucial to an integrated understanding of living systems. This review summarizes recent developments in volatile research from a metabolomics perspective with a focus on the role of recent technical innovation in developing new areas of volatile research and expanding the range of ecological interactions which may be mediated by volatile organic metabolites.

  5. Headspace solid-phase microextraction for wine volatile analysis.

    Science.gov (United States)

    Azzi-Achkouty, Samar; Estephan, Nathalie; Ouaini, Naïm; Rutledge, Douglas N

    2017-07-03

    The most commonly used technique to prepare samples for the analysis of wine volatile is the headspace solid-phase microextraction (HS-SPME). This method has gained popularity in last few years, as it is a unique solventless preparation technique. In this paper, a summary of recently published studies using HS-SPME for the analysis of wine aromas, with special emphasis on the method developed, has been compiled. Several papers are discussed in detail, mainly with respect to the SPME conditions used. A brief summary of the reviews related to HS-SPME analysis is given and discussed. Several parameters affecting the HS-SPME, such as the salt concentration and the agitation conditions, are used in the same way as used in several papers. The HS-SPME extraction proved to be sufficiently sensitive to satisfy legislative requirements related to low detection and quantification limits as well as method accuracy and precision requirements. However, in order to achieve the best performance and precision, the protocol needs to be optimized for each case. The effect of different parameters must be well characterized to ensure correct extraction and desorption to ensure the transfer of extracted compounds into the analytical system. The operating parameters, such as time, temperature, and agitation, must then be kept constant for all the samples.

  6. [Analysis of volatile composition of different specification of Panax notoginseng].

    Science.gov (United States)

    Li, Li-Ming; Ren, Bin; Guo, Jie-Wen; Deng, Zhi-Jun; Liu, Ruo-Xuan

    2013-06-01

    To analyse the volatile compositions of different specification of Panax notoginseng. Volatile compositions from different specification of Panax notoginseng were detected by Headspace Solid-Phase Micro-Extraction with GC/MS. Terpenoids were the main compositions in different specification of Panax Notoginseng, and a-guaiene was the fundamental ingredient. The type, content and quantity of the compounds were different in different type of Panax notoginseng. Terpenoids were the main pharmacodynamics of the volatile compositions of Panax notoginseng and worthy of further study.

  7. Electrophysiological and behavioral responses of pea weevil Bruchus pisorum L. (Coleóptera: Bruchidae to volatiles collected from its host Pisum sativum L

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    Ricardo Ceballos

    2015-06-01

    Full Text Available The pea weevil (Bruchus pisorum L. (Coleóptera: Bruchidae is one of the most damaging pests of pea (Pisum sativum L. We investigated the role of pea volatiles on the electrophysiological and behavioral response of B. pisorum using electroantennography (EAG and olfactometry bioassays. Plant volatiles emitted at different phenological stages were collected in situ by headspace on Porapak Q traps and analyzed through gas chromatography coupled to mass spectrometry (GC-MS. Most abundant volatiles identified in all phenological stages were terpenes and green leaf volatiles. All tested volatile extracts elicited significant EAG responses in both male and female B. pisorum, with females exhibiting a greater response (1.35 mV than males (1.02 mV to pea-pod volatiles. Volatiles from each phenological stage stimulated an attractant behavioral response of both males and females B. pisorum in olfactometer bioassay. A larger attraction of B. pisorum females was observed to volatiles from pods over other phenological stages (P < 0.001. These results suggest the relative importance of volatiles cues from plant mediating host location by B. pisorum. This work showed that plant volatiles elicited electrophysiological and behavioral responses and that B. pisorum female can discern between phenological stages of P. sativum based on those chemical cues.

  8. Volatile Compound Profiling by HS-SPME/GC-MS-FID of a Core Olive Cultivar Collection as a Tool for Aroma Improvement of Virgin Olive Oil

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    Lourdes García-Vico

    2017-01-01

    Full Text Available Virgin olive oil (VOO is the only food product requiring official sensory analysis to be classified in commercial categories, in which the evaluation of the aroma plays a very important role. The selection of parents, with the aim of obtaining new cultivars with improved oil aroma, is of paramount importance in olive breeding programs. We have assessed the volatile fraction by headspace-solid-phase microextraction/gas chromatography-mass spectrometry-flame ionization detection (HS-SPME/GC-MS-FID and the deduced aroma properties of VOO from a core set of olive cultivars (Core-36 which possesses most of the genetic diversity found in the World Olive Germplasm Collection (IFAPA Alameda del Obispo located in Cordoba, Spain. The VOO volatile fractions of Core-36 cultivars display a high level of variability. It is mostly made of compounds produced from polyunsaturated fatty acids through the lipoxygenase pathway, which confirms to be a general characteristic of the olive species (Olea europaea L.. The main group of volatile compounds in the oils was six straight-chain carbon compounds derived from linolenic acid, some of them being the main contributors to the aroma of the olive oils according to their odor activity values (OAV. The high level of variability found for the volatile fraction of the oils from Core-36 and, therefore, for the aroma odor notes, suggest that this core set may be a very useful tool for the choice of optimal parents in olive breeding programs in order to raise new cultivars with improved VOO aroma.

  9. Volatile Compound Profiling by HS-SPME/GC-MS-FID of a Core Olive Cultivar Collection as a Tool for Aroma Improvement of Virgin Olive Oil.

    Science.gov (United States)

    García-Vico, Lourdes; Belaj, Angjelina; Sánchez-Ortiz, Araceli; Martínez-Rivas, José M; Pérez, Ana G; Sanz, Carlos

    2017-01-14

    Virgin olive oil (VOO) is the only food product requiring official sensory analysis to be classified in commercial categories, in which the evaluation of the aroma plays a very important role. The selection of parents, with the aim of obtaining new cultivars with improved oil aroma, is of paramount importance in olive breeding programs. We have assessed the volatile fraction by headspace-solid-phase microextraction/gas chromatography-mass spectrometry-flame ionization detection (HS-SPME/GC-MS-FID) and the deduced aroma properties of VOO from a core set of olive cultivars (Core-36) which possesses most of the genetic diversity found in the World Olive Germplasm Collection (IFAPA Alameda del Obispo) located in Cordoba, Spain. The VOO volatile fractions of Core-36 cultivars display a high level of variability. It is mostly made of compounds produced from polyunsaturated fatty acids through the lipoxygenase pathway, which confirms to be a general characteristic of the olive species (Olea europaea L.). The main group of volatile compounds in the oils was six straight-chain carbon compounds derived from linolenic acid, some of them being the main contributors to the aroma of the olive oils according to their odor activity values (OAV). The high level of variability found for the volatile fraction of the oils from Core-36 and, therefore, for the aroma odor notes, suggest that this core set may be a very useful tool for the choice of optimal parents in olive breeding programs in order to raise new cultivars with improved VOO aroma.

  10. Analysis of the Behavior of Volatility in Crude Oil Price

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    Fernando Antonio Lucena Aiube

    2014-02-01

    Full Text Available This article analyzes volatility in the spot price of crude oil. In recent years the price has also increased reaching more than US$ 140/barrel in the last decade. Moreover, the negotiated trading volume in the futures market in recent years higher than the trading volume of the earlier years. How these changes have affected the volatility in the oil prices? Does the presence of huge players, which leads to an increase in the volume under negotiation, increase volatility? Has the persistence been affected? To answer these questions, we first estimated spot prices using the two-factor model of Schwartz and Smith. With this filtering process we can capture the entire information from the future term-structure. We then analyzed the estimated spot-price series to identify the stylized facts and then adjusted conditional volatility models of GARCH family. Our findings show that the volatility in the high prices period is not different from that of low prices. The shocks behaved as transitory and the persistence in the high prices period decreased. This fact has pricing and hedging implications for short-term derivatives.

  11. A Method for Software Requirement Volatility Analysis Using QFD

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    Yunarso Anang

    2016-10-01

    Full Text Available Changes of software requirements are inevitable during the development life cycle. Rather than avoiding the circumstance, it is easier to just accept it and find a way to anticipate those changes. This paper proposes a method to analyze the volatility of requirement by using the Quality Function Deployment (QFD method and the introduced degree of volatility. Customer requirements are deployed to software functions and subsequently to architectural design elements. And then, after determining the potential for changes of the design elements, the degree of volatility of the software requirements is calculated. In this paper the method is described using a flow diagram and illustrated using a simple example, and is evaluated using a case study.

  12. Sensory analysis and volatile compounds of olive oil (cv. Cobrancosa) from different irrigation regimes

    Energy Technology Data Exchange (ETDEWEB)

    Fernandes-Silva, A. A.; Falco, V.; Correia, C. M.; Villalobos, F. J.

    2013-05-01

    The aim of this study was to assess the effect of different irrigation strategies on the sensory quality of virgin olive oil VOO) from the cv. cobrancosa- integrated into a protected denomination of origin of Azeite de Tras-os-Montes in the Northeast of Portugal. Three irrigation treatments were applied: (T2)-full irrigation, which received a seasonal water equivalent of 100% of the estimated crop evapotranspiration (ET{sub c}), (T1)-continuous deficit irrigation (30% ETc) and (T0)- rainfed treatment. Data were collected from two consecutive crop years (2005-2006). Olive oil samples were analyzed for volatiles by GC-MS and the results compared with sensory evaluation data. Total volatile compounds tended to decrease with the amount of water applied. The characteristics pungent and bitter were more pronounced in olive oils from T0 and T1, which had higher polyphenolic concentrations, with a strong positive relationship with this variable and the bitter attribute. The Principal Components Analysis clearly separates the three olive oils from 2005, the driest year, and aggregates into a single group the three samples from 2006, suggesting no effect of irrigation on volatile compounds in years with a rainy spring and a marked effect in years with severe drought, suggesting that the effect of the trees’ water status on these variables occurs throughout the crop season and not just during the oil accumulation phase. In general, olive oil from the cv. Cobrançosa is more bitter than pungent and has a typical nutty sensory attribute shown by a strong positive relationship between benzaldehyde and the sensory notes of almonds and nuts. (Author) 34 refs.

  13. Analysis of breath volatile organic compounds as a screening tool for detection of Tuberculosis in cattle

    Science.gov (United States)

    • Keywords: bovine tuberculosis; Mycobacterium bovis; breath analysis; volatile organic compound; gas chromatography; mass spectrometry; NaNose • Introduction: This presentation describes two studies exploring the use of breath VOCs to identify Mycobacterium bovis infection in cattle. • Methods: ...

  14. ANALYSIS OF MACROECONOMIC DETERMINANTS OF EXCHANGE RATE VOLATILITY IN INDIA

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    Anita Mirchandani

    2013-01-01

    Full Text Available The Foreign Exchange Market in India has undergone substantial changes over last decade. It is imperative by the excessive volatility of Indian Rupee causing its depreciation against major dominating currencies in international market. This research has been carried out in order to investigate various macroeconomic variables leading to acute variations in the exchange rate of a currency. An attempt has been made to review the probable reasons for the depreciation of the Rupee and analyse different macroeconomic determinants that have impact on the volatility of exchange rate and their extent of correlation with the same.

  15. Current Challenges in Volatile Organic Compounds Analysis as Potential Biomarkers of Cancer

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    Kamila Schmidt

    2015-01-01

    Full Text Available An early diagnosis and appropriate treatment are crucial in reducing mortality among people suffering from cancer. There is a lack of characteristic early clinical symptoms in most forms of cancer, which highlights the importance of investigating new methods for its early detection. One of the most promising methods is the analysis of volatile organic compounds (VOCs. VOCs are a diverse group of carbon-based chemicals that are present in exhaled breath and biofluids and may be collected from the headspace of these matrices. Different patterns of VOCs have been correlated with various diseases, cancer among them. Studies have also shown that cancer cells in vitro produce or consume specific VOCs that can serve as potential biomarkers that differentiate them from noncancerous cells. This review identifies the current challenges in the investigation of VOCs as potential cancer biomarkers, by the critical evaluation of available matrices for the in vivo and in vitro approaches in this field and by comparison of the main extraction and detection techniques that have been applied to date in this area of study. It also summarises complementary in vivo, ex vivo, and in vitro studies conducted to date in order to try to identify volatile biomarkers of cancer.

  16. Multifactor analysis of multiscaling in volatility return intervals

    Science.gov (United States)

    Wang, Fengzhong; Yamasaki, Kazuko; Havlin, Shlomo; Stanley, H. Eugene

    2009-01-01

    We study the volatility time series of 1137 most traded stocks in the U.S. stock markets for the two-year period 2001-2002 and analyze their return intervals τ , which are time intervals between volatilities above a given threshold q . We explore the probability density function of τ , Pq(τ) , assuming a stretched exponential function, Pq(τ)˜e-τγ . We find that the exponent γ depends on the threshold in the range between q=1 and 6 standard deviations of the volatility. This finding supports the multiscaling nature of the return interval distribution. To better understand the multiscaling origin, we study how γ depends on four essential factors, capitalization, risk, number of trades, and return. We show that γ depends on the capitalization, risk, and return but almost does not depend on the number of trades. This suggests that γ relates to the portfolio selection but not on the market activity. To further characterize the multiscaling of individual stocks, we fit the moments of τ , μm≡⟨(τ/⟨τ⟩)m⟩1/m , in the range of 10return but not on the number of trades, and its tendency is opposite to that of γ . Moreover, we show that δ decreases with increasing γ approximately by a linear relation. The return intervals demonstrate the temporal structure of volatilities and our findings suggest that their multiscaling features may be helpful for portfolio optimization.

  17. Qualitative analysis of volatile organic compounds on biochar

    Science.gov (United States)

    Qualitative identification of sorbed volatile organic compounds (VOCs) on biochar was conducted by headspace thermal desorption coupled to capillary gas chromatographic-mass spectrometry. VOCs may have a mechanistic role influencing plant and microbial responses to biochar amendments, since VOCs ca...

  18. The GC/MS Analysis of Volatile Components Extracted by Different Methods from Exocarpium Citri Grandis

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    Zhisheng Xie

    2013-01-01

    Full Text Available Volatile components from Exocarpium Citri Grandis (ECG were, respectively, extracted by three methods, that is, steam distillation (SD, headspace solid-phase microextraction (HS-SPME, and solvent extraction (SE. A total of 81 compounds were identified by gas chromatography-mass spectrometry including 77 (SD, 56 (HS-SPME, and 48 (SE compounds, respectively. Despite of the extraction method, terpenes (39.98~57.81% were the main volatile components of ECG, mainly germacrene-D, limonene, 2,6,8,10,14-hexadecapentaene, 2,6,11,15-tetramethyl-, (E,E,E-, and trans-caryophyllene. Comparison was made among the three methods in terms of extraction profile and property. SD relatively gave an entire profile of volatile in ECG by long-time extraction; SE enabled the analysis of low volatility and high molecular weight compounds but lost some volatiles components; HS-SPME generated satisfactory extraction efficiency and gave similar results to those of SD at analytical level when consuming less sample amount, shorter extraction time, and simpler procedure. Although SD and SE were treated as traditionally preparative extractive techniques for volatiles in both small batches and large scale, HS-SPME coupled with GC/MS could be useful and appropriative for the rapid extraction and qualitative analysis of volatile components from medicinal plants at analytical level.

  19. Microdistillation and analysis of volatiles from eight ornamental Salvia taxa.

    Science.gov (United States)

    Tabanca, Nurhayat; Demirci, Betul; Turner, Jimmy L; Pounders, Cecil; Demirci, Fatih; Başer, Kemal Hüsnü Can; Wedge, David E

    2010-09-01

    Volatile compounds from seven Salvia species and one interspecific hybrid growing at the Dallas Arboretum and Botanical Garden, Texas, US. Salvia coccinea, S. farinacea, S. greggii, S. leucantha, S. longispicata x farinacea, S. madrensis, S. roemeriana and S. splendens were investigated for their chemical compositions using a microdistillation technique. Volatiles were analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC/MS). One hundred and twenty seven compounds were identified representing 94.3-99.7% of the oils. The major components in each of the seven species were as follows: S. coccinea (Z)-3-hexenal (31%), viridiflorol (19%); S. farinacea 1-octen-3-ol (30%) and (Z)-3-hexenal (23%); S. greggii 1,8-cineole (22%), borneol (17%), camphene (11%) and alpha-pinene (10%); S. leucantha limonene (35%) and alpha-pinene (17%); S. longispicata x farinacea 1-octen-3-ol (50%) and (Z)-3-hexenal (24%); S. madrensis (Z)-3-hexenal (53%); S. roemeriana limonene (49%) and alpha-pinene (20%); and S. splendens (Z)-3-hexenal (36%), 2,5-dimethoxy-p-cymene (19%) and linalool (11%). The microdistillation method was fast, practical and a useful technique that enabled the isolation of the volatiles in samples when only limited quantities were available.

  20. Malware Memory Analysis of the IVYL Linux Rootkit: Investigating a Publicly Available Linux Rootkit Using the Volatility Memory Analysis Framework

    Science.gov (United States)

    2015-04-01

    Malware memory analysis of the IVYL Linux rootkit Investigating a publicly available Linux rootkit using the Volatility memory analysis...Abstract …….. This report is the second in a series that will examine Linux Volatility-specific memory malware-based analysis techniques...described therein are not applicable to Linux -based analyses including data carving and anti-virus scanning. Thus, with minimal use of scanner-based

  1. Comparative Analysis of Flower Volatiles from Nine Citrus at Three Blooming Stages

    Directory of Open Access Journals (Sweden)

    Muhammad Azam

    2013-11-01

    Full Text Available Volatiles from flowers at three blooming stages of nine citrus cultivars were analyzed by headspace-solid phase microextraction (HS-SPME-GC-MS. Up to 110 volatiles were detected, with 42 tentatively identified from citrus flowers for the first time. Highest amounts of volatiles were present in fully opened flowers of most citrus, except for pomelos. All cultivars were characterized by a high percentage of either oxygenated monoterpenes or monoterpene hydrocarbons, and the presence of a high percentage of nitrogen containing compounds was also observed. Flower volatiles varied qualitatively and quantitatively among citrus types during blooming. Limonene was the most abundant flower volatile only in citrons; α-citral and β-citral ranked 2nd and 3rd only for Bergamot, and unopened flowers of Ponkan had a higher amount of linalool and β-pinene while much lower amount of γ-terpinene and p-cymene than Satsuma. Taking the average of all cultivars, linalool and limonene were the top two volatiles for all blooming stages; β-pinene ranked 3rd in unopened flowers, while indole ranked 3rd for half opened and fully opened flower volatiles. As flowers bloomed, methyl anthranilate increased while 2-hexenal and p-cymene decreased. In some cases, a volatile could be high in both unopened and fully opened flowers but low in half opened ones. Through multivariate analysis, the nine citrus cultivars were clustered into three groups, consistent with the three true citrus types. Furthermore, an influence of blooming stages on clustering was observed, especially with hybrids Satsuma and Huyou. Altogether, it was suggested that flower volatiles can be suitable markers for revealing the genetic relationships between citrus cultivars but the same blooming stage needs to be strictly controlled.

  2. Analysis of volatile components in herbal pair herba schizonepetae-ramulus cinnamomi

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Analysis of volatile components in herbal pair (HP) herba schizonepetae-ramulus cinnamomi (HS-RC),single herb HS and RC was carried out by gas chromatography-mass spectrometry (GC-MS) data and chemometric resolution method (CRM).The two-dimensional data obtained from GC-MS instruments were resolved into a pure chromatogram and a mass spectrum of each chemical compound by CRM.In total,47,61 and 51 chemical components in volatile oil of HS,RC,and HP HS-RC were respectively determined qualitatively and quantitatively,accounting for 90.52%,88.37%,and 88.72% total contents of volatile oil of HS,RC,and HP HS-RC,respectively.The number of the volatile components of HP HS-RC is almost the addition of that of two single herbs,but their relative contents are changed.

  3. Analysis of seven salad rocket (Eruca sativa) accessions: The relationships between sensory attributes and volatile and non-volatile compounds.

    Science.gov (United States)

    Bell, Luke; Methven, Lisa; Signore, Angelo; Oruna-Concha, Maria Jose; Wagstaff, Carol

    2017-03-01

    Sensory and chemical analyses were performed on accessions of rocket (Eruca sativa) to determine phytochemical influences on sensory attributes. A trained panel was used to evaluate leaves, and chemical data were obtained for polyatomic ions, amino acids, sugars and organic acids. These chemical data (and data of glucosinolates, flavonols and headspace volatiles previously reported) were used in Principal Component Analysis (PCA) to determine variables statistically important to sensory traits. Significant differences were observed between samples for polyatomic ion and amino acid concentrations. PCA revealed strong, positive correlations between glucosinolates, isothiocyanates and sulfur compounds with bitterness, mustard, peppery, warming and initial heat mouthfeel traits. The ratio between glucosinolates and sugars inferred reduced perception of bitter aftereffects. We highlight the diversity of E. sativa accessions from a sensory and phytochemical standpoint, and the potential for breeders to create varieties that are nutritionally and sensorially superior to existing ones.

  4. Experimental determination of the partitioning coefficient and volatility of important BVOC oxidation products using the Aerosol Collection Module (ACM) coupled to a PTR-ToF-MS

    Science.gov (United States)

    Gkatzelis, G.; Hohaus, T.; Tillmann, R.; Schmitt, S. H.; Yu, Z.; Schlag, P.; Wegener, R.; Kaminski, M.; Kiendler-Scharr, A.

    2015-12-01

    Atmospheric aerosol can alter the Earth's radiative budget and global climate but can also affect human health. A dominant contributor to the submicrometer particulate matter (PM) is organic aerosol (OA). OA can be either directly emitted through e.g. combustion processes (primary OA) or formed through the oxidation of organic gases (secondary organic aerosol, SOA). A detailed understanding of SOA formation is of importance as it constitutes a major contribution to the total OA. The partitioning between the gas and particle phase as well as the volatility of individual components of SOA is yet poorly understood adding uncertainties and thus complicating climate modelling. In this work, a new experimental methodology was used for compound-specific analysis of organic aerosol. The Aerosol Collection Module (ACM) is a newly developed instrument that deploys an aerodynamic lens to separate the gas and particle phase of an aerosol. The particle phase is directed to a cooled sampling surface. After collection particles are thermally desorbed and transferred to a detector for further analysis. In the present work, the ACM was coupled to a Proton Transfer Reaction-Time of Flight-Mass Spectrometer (PTR-ToF-MS) to detect and quantify organic compounds partitioning between the gas and particle phase. This experimental approach was used in a set of experiments at the atmosphere simulation chamber SAPHIR to investigate SOA formation. Ozone oxidation with subsequent photochemical aging of β-pinene, limonene and real plant emissions from Pinus sylvestris (Scots pine) were studied. Simultaneous measurement of the gas and particle phase using the ACM-PTR-ToF-MS allows to report partitioning coefficients of important BVOC oxidation products. Additionally, volatility trends and changes of the SOA with photochemical aging are investigated and compared for all systems studied.

  5. [Application characteristics and situation analysis of volatile oils in database of Chinese patent medicine].

    Science.gov (United States)

    Wang, Sai-Jun; Wu, Zhen-Feng; Yang, Ming; Wang, Ya-Qi; Hu, Peng-Yi; Jie, Xiao-Lu; Han, Fei; Wang, Fang

    2014-09-01

    Aromatic traditional Chinese medicines have a long history in China, with wide varieties. Volatile oils are active ingredients extracted from aromatic herbal medicines, which usually contain tens or hundreds of ingredients, with many biological activities. Therefore, volatile oils are often used in combined prescriptions and made into various efficient preparations for oral administration or external use. Based on the sources from the database of Newly Edited National Chinese Traditional Patent Medicines (the second edition), the author selected 266 Chinese patent medicines containing volatile oils in this paper, and then established an information sheet covering such items as name, dosage, dosage form, specification and usage, and main functions. Subsequently, on the basis of the multidisciplinary knowledge of pharmaceutics, traditional Chinese pharmacology and basic theory of traditional Chinese medicine, efforts were also made in the statistics of the dosage form and usage, variety of volatile oils and main functions, as well as the status analysis on volatile oils in terms of the dosage form development, prescription development, drug instruction and quality control, in order to lay a foundation for the further exploration of the market development situations of volatile oils and the future development orientation.

  6. Volatility return intervals analysis of the Japanese market

    Science.gov (United States)

    Jung, W.-S.; Wang, F. Z.; Havlin, S.; Kaizoji, T.; Moon, H.-T.; Stanley, H. E.

    2008-03-01

    We investigate scaling and memory effects in return intervals between price volatilities above a certain threshold q for the Japanese stock market using daily and intraday data sets. We find that the distribution of return intervals can be approximated by a scaling function that depends only on the ratio between the return interval τ and its mean . We also find memory effects such that a large (or small) return interval follows a large (or small) interval by investigating the conditional distribution and mean return interval. The results are similar to previous studies of other markets and indicate that similar statistical features appear in different financial markets. We also compare our results between the period before and after the big crash at the end of 1989. We find that scaling and memory effects of the return intervals show similar features although the statistical properties of the returns are different.

  7. Comparative analysis of headspace volatiles of Chinese Rosa rugosa.

    Science.gov (United States)

    Feng, Li-Guo; Chen, Chen; Sheng, Li-Xia; Liu, Ping; Tao, Jun; Su, Jia-Le; Zhao, Lan-Yong

    2010-11-16

    The floral headspace compounds of Chinese Rosa rugosa germplasms that were isolated by an automated headspace sampler with built-in trap, and followed by gas chromatography-mass spectrometry for identification and quantification. Up to 33 volatile compounds were identified from the 23 rose germplasms, including nine alcohols, five esters, three alkanes, 10 terpenes, three aldehydes, two ketones, and one ether. The main floral components identified were 2-phenylethanol, β-citronellol, ethanol, and n-hexane. 'xizi', 'miaofengshan', 'xiangciguo', and 'tangbai' contained the highest amounts of 2-phenylethanol at 84.66 μg·g⁻¹, β-citronellol at 70.98 μg·g⁻¹, ethanol at 83.87 μg·g⁻¹, and n-hexane at 18.23 μg·g⁻¹, respectively. 'Rongchengyesheng', 'tanghong', 'xizi', 'miaofengshan', and 'baizizhi' could be considered good materials for extracting rose oil and breeding new cultivars.

  8. Evaluation of fast volatile analysis for detection of Botrytis cinerea infections in strawberry.

    Science.gov (United States)

    Vandendriessche, Thomas; Keulemans, Johan; Geeraerd, Annemie; Nicolai, Bart M; Hertog, Maarten L A T M

    2012-12-01

    Grey mold (Botrytis cinerea) is one of the major phytopathogens causing serious losses during strawberry postharvest and storage. B. cinerea-host interaction affect emissions of volatile compounds during infection resulting in a characteristic earthy, mushroom odor. Therefore, the objective of this study was to evaluate two analytical techniques based on fast volatile analysis on their performance for monitoring evolution and early detection of B. cinerea infections in strawberry. In a first experiment headspace multi-capillary column-ion mobility spectrometry (HS MCC-IMS) has been successfully used to evaluate development of strawberry aroma during shelflife. In a second experiment the same technique has been used to detect the degree of B. cinerea infection through changes in the volatile profile. Additionally, these samples were analyzed with headspace solid-phase-microextraction fast GC-MS (HS SPME fast GC-MS). Both HS MCC-IMS and HS SPME fast GC-MS could determine the changes in volatile composition as a function of the degree of B. cinerea infection as determined by an enzyme-linked immunosorbent assay (ELISA) and could be used to follow the evolution of infection. According to the ELISA data, some fruit were infected even without any symptoms and volatiles produced by the fungus may be overshadowed by the fruit volatiles. Therefore, both analytical techniques could not be used for early detection of B. cinerea infections. After identification of the volatile compounds and multivariate data analysis, potential biomarkers specific for B. cinerea were highlighted, being 3-methylbutanal, cis-4-decenal, 2-methyl-1-butanol, 2-methyl-1-propanol, 1-octen-3-one and 1-octen-3-ol.

  9. Hydrogen Safety Project chemical analysis support task: Window C'' volatile organic analysis

    Energy Technology Data Exchange (ETDEWEB)

    Gillespie, B.M.; Stromatt, R.W.; Ross, G.A.; Hoope, E.A.

    1992-01-01

    This data package contains the results obtained by Pacific Northwest Laboratory (PNL) staff in the characterization of samples for the 101-SY Hydrogen Safety Project. The samples were submitted for analysis by Westinghouse Hanford Company (WHC) under the Technical Project Plan (TPP) 17667 and the Quality Assurance Plan MCS-027. They came from a core taken during Window C'' after the May 1991 gas release event. The analytical procedures required for analysis were defined in the Test Instructions (TI) prepared by the PNL 101-SY Analytical Chemistry Laboratory (ACL) Project Management Office in accordance with the TPP and the QA Plan. The requested analysis for these samples was volatile organic analysis. The quality control (QC) requirements for each sample are defined in the Test Instructions for each sample. The QC requirements outlined in the procedures and requested in the WHC statement of work were followed.

  10. Hydrogen Safety Project chemical analysis support task: Window ``C`` volatile organic analysis

    Energy Technology Data Exchange (ETDEWEB)

    Gillespie, B.M.; Stromatt, R.W.; Ross, G.A.; Hoope, E.A.

    1992-01-01

    This data package contains the results obtained by Pacific Northwest Laboratory (PNL) staff in the characterization of samples for the 101-SY Hydrogen Safety Project. The samples were submitted for analysis by Westinghouse Hanford Company (WHC) under the Technical Project Plan (TPP) 17667 and the Quality Assurance Plan MCS-027. They came from a core taken during Window ``C`` after the May 1991 gas release event. The analytical procedures required for analysis were defined in the Test Instructions (TI) prepared by the PNL 101-SY Analytical Chemistry Laboratory (ACL) Project Management Office in accordance with the TPP and the QA Plan. The requested analysis for these samples was volatile organic analysis. The quality control (QC) requirements for each sample are defined in the Test Instructions for each sample. The QC requirements outlined in the procedures and requested in the WHC statement of work were followed.

  11. Analysis of Volatile Compounds from Solanumbetaceum Cav. Fruits from Panama by Head-Space Micro Extraction

    Directory of Open Access Journals (Sweden)

    Armando A. Durant

    2013-01-01

    Full Text Available The characterization of the volatile compounds of two varieties of Solanum betaceum Cav. by means of headspace solid-phase microextraction (HS-SPME coupled with gas chromatography-mass spectrometry ( GC-MS i s presented. The HS-SPME method for extraction of the volatiles compounds was optimized by using a 2 3 central composite design. Maximum extraction of volatile compounds was achieved by using a divinylbenzene-carboxen-polydimethylsiloxane (DVB/CAR/PDMS fiber, extraction temperature 76° C, incubation time 44 min, and extraction time of 46 min. The main types of compounds detected in both varieties are terpenoids, followed by aromatics, esters, and aldehydes. Golden-yellow cultivars contained higher levels of esters and terpenes, while the reddish-purple variety contained a significant amount of aromatic compounds. The data structure of the chemical information obtained as well as the relationship between variables was evaluated by means of principal component analysis and cluster analysis.

  12. Real-Time and Delayed Analysis of Tree and Shrub Cores as Indicators of Subsurface Volatile Organic Compound Contamination, Durham Meadows Superfund Site, Durham, Connecticut, August 29, 2006

    Science.gov (United States)

    Vroblesky, Don A.; Willey, Richard E.; Clifford, Scott; Murphy, James J.

    2008-01-01

    This study examined volatile organic compound concentrations in cores from trees and shrubs for use as indicators of vadose-zone contamination or potential vapor intrusion by volatile organic compounds into buildings at the Durham Meadows Superfund Site, Durham, Connecticut. The study used both (1) real-time tree- and shrub-core analysis, which involved field heating the core samples for 5 to 10 minutes prior to field analysis, and (2) delayed analysis, which involved allowing the gases in the cores to equilibrate with the headspace gas in the sample vials unheated for 1 to 2 days prior to analysis. General correspondence was found between the two approaches, indicating that preheating and field analysis of vegetation cores is a viable approach to real-time monitoring of subsurface volatile organic compounds. In most cases, volatile organic compounds in cores from trees and shrubs at the Merriam Manufacturing Company property showed a general correspondence to the distribution of volatile organic compounds detected in a soil-gas survey, despite the fact that most of the soil-gas survey data in close proximity to the relevant trees were collected about 3 years prior to the tree-core collection. Most of the trees cored at the Durham Meadows Superfund Site, outside of the Merriam Manufacturing Company property, contained no volatile organic compounds and were in areas where indoor air sampling and soil-gas sampling showed little or no volatile organic compound concentrations. An exception was tree DM11, which contained barely detectable concentrations of trichloroethene near a house where previous investigations found low concentrations of trichloroethene (0.13 to 1.2 parts per billion by volume) in indoor air and 7.7 micrograms per liter of trichloroethene in the ground water. The barely detectable concentration of trichloroethene in tree DM11 and the lack of volatile organic compound detection in nearby tree DM10 (adjacent to the well having 7.7 micrograms of

  13. Nanogram-scale preparation and NMR analysis for mass-limited small volatile compounds.

    Directory of Open Access Journals (Sweden)

    Satoshi Nojima

    Full Text Available Semiochemicals are often produced in infinitesimally small quantities, so their isolation requires large amounts of starting material, not only requiring significant effort in sample preparation, but also resulting in a complex mixture of compounds from which the bioactive compound needs to be purified and identified. Often, compounds cannot be unambiguously identified by their mass spectra alone, and NMR analysis is required for absolute chemical identification, further exacerbating the situation because NMR is relatively insensitive and requires large amounts of pure analyte, generally more than several micrograms. We developed an integrated approach for purification and NMR analysis of <1 µg of material. Collections from high performance preparative gas-chromatography are directly eluted with minimal NMR solvent into capillary NMR tubes. With this technique, (1H-NMR spectra were obtained on 50 ng of geranyl acetate, which served as a model compound, and reasonable H-H COSY NMR spectra were obtained from 250 ng of geranyl acetate. This simple off-line integration of preparative GC and NMR will facilitate the purification and chemical identification of novel volatile compounds, such as insect pheromones and other semiochemicals, which occur in minute (sub-nanogram, and often limited, quantities.

  14. Comparison of Three Methods for Extraction of Volatile Lipid Oxidation Products from Food Matrices for GC–MS Analysis

    DEFF Research Database (Denmark)

    Thomsen, Birgitte Raagaard; Yesiltas, Betül; Sørensen, Ann-Dorit Moltke

    2016-01-01

    The aim of this study was to compare three different collection methods; purge and trap, solid phase micro extraction and automated dynamic headspace/thermal desorption, all followed by GC–MS analysis used for the measurements of concentrations of volatile oxidation products in three different food...... matrices, namely oil, emulsion and milk. The linearity ranges of calibration curves obtained by the three different methods were compared for oil samples. Overall, the results showed that the three collection methods were comparable, although there were large differences in the linearity range...... of the calibration curves depending on the collection method. However, some challenges were observed for solid phase micro extraction and automated dynamic headspace/thermal desorption, namely, competition problems and overestimation of concentration by calibration curves, respectively. Based on the results, we...

  15. Microextraction and Gas Chromatography/Mass Spectrometry for improved analysis of geosmin and other fungal "off" volatiles in grape juice.

    Science.gov (United States)

    Morales-Valle, H; Silva, L C; Paterson, R R M; Oliveira, J M; Venâncio, A; Lima, N

    2010-10-01

    Geosmin is a volatile fungal metabolite with an earthy aroma produced in grape products from rotten grapes. The accumulation of geosmin in grapes is caused by the interaction of Botrytis cinerea and Penicillium expansum. Solid Phase Microextraction (SPME) has great utility for collecting volatile compounds in wine. However, contamination with earthy odours may have occurred previously in the must and novel methods are required for this commodity. In the present report, several parameters of the SPME were evaluated to optimize geosmin extraction. The method permitted quantification of geosmin and other fungal volatiles by Gas Chromatography-Mass Spectrometer (GC-MS) at very low concentrations. Limits of detection and quantification (L(D) and L(Q)) for geosmin were 4.7 ng L(-1) and 15.6 ng L(-1) respectively. The RSD was 4.1% and the recovery rates ranged from 115% to 134%. Uniquely, haloanisoles were analyzed by using only one internal standard (2,3,6-trichloroanisole) thus avoiding the synthesis of deuterated anisole analogues that are used as internal standard in other methods. The method was used for the analysis of grape juice samples inoculated with B. cinerea and P. expansum. Geosmin and methylisoborneol were the compounds that appeared to contribute most to earthy odours, although other fungal compounds which are claimed to cause earthy or mouldy off-odours were detected (e.g. 1-octen-3-ol and fenchol).

  16. Comparative Analysis of Headspace Volatiles of Chinese Rosa rugosa

    Directory of Open Access Journals (Sweden)

    Lan-Yong Zhao

    2010-11-01

    Full Text Available The floral headspace compounds of Chinese Rosa rugosa germplasms that were isolated by an automated headspace sampler with built-in trap, and followed by gas chromatography-mass spectrometry for identification and quantification. Up to 33 volatile compounds were identified from the 23 rose germplasms, including nine alcohols, five esters, three alkanes, 10 terpenes, three aldehydes, two ketones, and one ether. The main floral components identified were 2-phenylethanol, β-citronellol, ethanol, and n-hexane. ‘xizi’, ‘miaofengshan’, ‘xiangciguo’, and ‘tangbai’ contained the highest amounts of 2-phenylethanol  at 84.66 μg·g-1, β-citronellol at 70.98 μg·g-1, ethanol at 83.87 μg·g-1, and n-hexane at 18.23 μg·g-1, respectively. ‘Rongchengyesheng’, ‘tanghong’, ‘xizi’, ‘miaofengshan’, and ‘baizizhi’ could be considered good materials for extracting rose oil and breeding new cultivars.

  17. Analysis of volatile organic compounds released during food decaying processes.

    Science.gov (United States)

    Phan, Nhu-Thuc; Kim, Ki-Hyun; Jeon, Eui-Chan; Kim, Uk-Hun; Sohn, Jong Ryeul; Pandey, Sudhir Kumar

    2012-03-01

    A number of volatile organic compounds (VOCs) including acetone, methyl ethyl ketone, toluene, ethylbenzene, m,p-xylene, styrene, and o- xylene released during food decaying processes were measured from three types of decaying food samples (Kimchi (KC), fresh fish (FF), and salted fish (SF)). To begin with, all the food samples were contained in a 100-mL throwaway syringe. These samples were then analyzed sequentially for up to a 14-day period. The patterns of VOC release contrasted sharply between two types of fish (FF and SF) and KC samples. A comparison of data in terms of total VOC showed that the mean values for the two fish types were in the similar magnitude with 280 ± 579 (FF) and 504 ± 1,089 ppmC (SF), while that for KC was much lower with 16.4 ± 7.6 ppmC. There were strong variations in VOC emission patterns during the food decaying processes between fishes and KC that are characterized most sensitively by such component as styrene. The overall results of this study indicate that concentration levels of the VOCs differed significantly between the food types and with the extent of decaying levels through time.

  18. L-VRAP—A lunar volatile resources analysis package for lunar exploration

    Science.gov (United States)

    Wright, I. P.; Sheridan, S.; Morse, A. D.; Barber, S. J.; Merrifield, J. A.; Waugh, L. J.; Howe, C. J.; Gibson, E. K.; Pillinger, C. T.

    2012-12-01

    The Lunar Volatile Resources Analysis Package (L-VRAP) has been conceived to deliver some of the objectives of the proposed Lunar Lander mission currently being studied by the European Space Agency. The purpose of the mission is to demonstrate and develop capability; the impetus is very much driven by a desire to lay the foundations for future human exploration of the Moon. Thus, L-VRAP has design goals that consider lunar volatiles from the perspective of both their innate scientific interest and also their potential for in situ utilisation as a resource. The device is a dual mass spectrometer system and is capable of meeting the requirements of the mission with respect to detection, quantification and characterisation of volatiles. Through the use of appropriate sampling techniques, volatiles from either the regolith or atmosphere (exosphere) can be analysed. Furthermore, since L-VRAP has the capacity to determine isotopic compositions, it should be possible for the instrument to determine the sources of the volatiles that are found on the Moon (be they lunar per se, extra-lunar, or contaminants imparted by the mission itself).

  19. Comparative Analysis of the Volatile Fraction of Fruit Juice from Different Citrus Species

    Science.gov (United States)

    Alamar, M. Carmen; Gutiérrez, Abelardo; Granell, Antonio

    2011-01-01

    The volatile composition of fruit from four Citrus varieties (Powell Navel orange, Clemenules mandarine, and Fortune mandarine and Chandler pummelo) covering four different species has been studied. Over one hundred compounds were profiled after HS-SPME-GC-MS analysis, including 27 esters, 23 aldehydes, 21 alcohols, 13 monoterpene hydrocarbons, 10 ketones, 5 sesquiterpene hydrocarbons, 4 monoterpene cyclic ethers, 4 furans, and 2 aromatic hydrocarbons, which were all confirmed with standards. The differences in the volatile profile among juices of these varieties were essentially quantitative and only a few compounds were found exclusively in a single variety, mainly in Chandler. The volatile profile however was able to differentiate all four varieties and revealed complex interactions between them including the participation in the same biosynthetic pathway. Some compounds (6 esters, 2 ketones, 1 furan and 2 aromatic hydrocarbons) had never been reported earlier in Citrus juices. This volatile profiling platform for Citrus juice by HS-SPME-GC-MS and the interrelationship detected among the volatiles can be used as a roadmap for future breeding or biotechnological applications. PMID:21818287

  20. Comparative analysis of the volatile fraction of fruit juice from different Citrus species.

    Directory of Open Access Journals (Sweden)

    M Carmen González-Mas

    Full Text Available The volatile composition of fruit from four Citrus varieties (Powell Navel orange, Clemenules mandarine, and Fortune mandarine and Chandler pummelo covering four different species has been studied. Over one hundred compounds were profiled after HS-SPME-GC-MS analysis, including 27 esters, 23 aldehydes, 21 alcohols, 13 monoterpene hydrocarbons, 10 ketones, 5 sesquiterpene hydrocarbons, 4 monoterpene cyclic ethers, 4 furans, and 2 aromatic hydrocarbons, which were all confirmed with standards. The differences in the volatile profile among juices of these varieties were essentially quantitative and only a few compounds were found exclusively in a single variety, mainly in Chandler. The volatile profile however was able to differentiate all four varieties and revealed complex interactions between them including the participation in the same biosynthetic pathway. Some compounds (6 esters, 2 ketones, 1 furan and 2 aromatic hydrocarbons had never been reported earlier in Citrus juices. This volatile profiling platform for Citrus juice by HS-SPME-GC-MS and the interrelationship detected among the volatiles can be used as a roadmap for future breeding or biotechnological applications.

  1. Analysis of volatile components, fatty acids, and phytosterols of Abies koreana growing in Poland.

    Science.gov (United States)

    Wajs-Bonikowska, Anna; Olejnika, Karol; Bonikowski, Radosław; Banaszczakb, Piotr

    2013-09-01

    Extracts and essential oils from seeds as well as essential oils from cone scales and needles with twigs of the Abies koreana population were studied. An analysis of Korean fir essential oils allowed us to determine 147 volatile compounds. The identified compounds constituted 97-99% of the seed, cone and needle oils. The main volatile in the seed and needle oils was limonene (56.6% and 23.4%, respectively), while the predominant volatile in cone oils was alpha-pinene (51.2%). Korean fir seeds provided a rich source of both essential oil (3.8-8.5%) and extract, which was isolated with a 24.5% yield and contained numerous groups of fatty acids and phytosterols (414 microg/100g extract). The most prominent fatty acids were unsaturated, among which linoleic (41.2%) and oleic (31.2%) fatty acid were the main ones while the dominant sterols were isomers of ergostadienol and beta-sitosterol. A. koreana seeds, cones and needles are a source of many volatile bioactive compounds while the seed extract, with a pleasant scent, contained not only volatiles, but also fractions rich in fatty acids and phytosterols. These facts make A. koreana essential oils and especially the seed extract potential components of cosmetics.

  2. Detection of diseased plants by analysis of volatile organic compound emission

    NARCIS (Netherlands)

    Jansen, R.M.C.; Wildt, J.; Kappers, I.F.; Bouwmeester, H.J.; Hofstee, J.W.; Henten, van E.

    2011-01-01

    This review focuses on the detection of diseased plants by analysis of volatile organic compound (VOC) emissions. It includes an overview of studies that report on the impact of infectious and noninfectious diseases on these emissions and discusses the specificity of disease-induced emissions. The

  3. Detection of diseased plants by analysis of volatile organic compound emission

    NARCIS (Netherlands)

    Jansen, R.M.C.; Wildt, J.; Kappers, I.F.; Bouwmeester, H.J.; Hofstee, J.W.; Henten, van E.

    2011-01-01

    This review focuses on the detection of diseased plants by analysis of volatile organic compound (VOC) emissions. It includes an overview of studies that report on the impact of infectious and noninfectious diseases on these emissions and discusses the specificity of disease-induced emissions. The r

  4. Analysis of volatiles of malt whisky by solid-phase microextraction and stir bar sorptive extraction.

    Science.gov (United States)

    Demyttenaere, Jan C R; Martínez, Jorge I Sánchez; Verhé, Roland; Sandra, Pat; De Kimpe, Norbert

    2003-01-24

    Blended Scotch whisky was analysed by solid-phase microextraction (SPME) and stir bar sorptive extraction (SBSE) to study the composition of the volatiles. For SPME analysis, three different fibres were compared, poly(dimethylsiloxane) (PDMS) (100 microm). poly(acrylate) (PA) (85 microm) and divinylbenzene-Carboxen on poly(dimethylsiloxane) (DVB-CAR-(PDMS) (50/30 microm). It was found that the PDMS and DVB-CAR-PDMS fibres showed a higher enrichment capacity than PA as well as a better reproducibility. The influence of sampling time, temperature and salt addition on the enrichment of volatiles as well as the difference between liquid and headspace SPME were studied. An optimum SPME method was developed. Finally a more recent sample preparation technique, namely SBSE was evaluated to extract whisky volatiles.

  5. Fingerprinting Breast Cancer vs. Normal Mammary Cells by Mass Spectrometric Analysis of Volatiles

    Science.gov (United States)

    He, Jingjing; Sinues, Pablo Martinez-Lozano; Hollmén, Maija; Li, Xue; Detmar, Michael; Zenobi, Renato

    2014-06-01

    There is increasing interest in the development of noninvasive diagnostic methods for early cancer detection, to improve the survival rate and quality of life of cancer patients. Identification of volatile metabolic compounds may provide an approach for noninvasive early diagnosis of malignant diseases. Here we analyzed the volatile metabolic signature of human breast cancer cell lines versus normal human mammary cells. Volatile compounds in the headspace of conditioned culture medium were directly fingerprinted by secondary electrospray ionization-mass spectrometry. The mass spectra were subsequently treated statistically to identify discriminating features between normal vs. cancerous cell types. We were able to classify different samples by using feature selection followed by principal component analysis (PCA). Additionally, high-resolution mass spectrometry allowed us to propose their chemical structures for some of the most discriminating molecules. We conclude that cancerous cells can release a characteristic odor whose constituents may be used as disease markers.

  6. Quantitative analysis of some volatile components in Mimusops elengi L.

    Directory of Open Access Journals (Sweden)

    Chantana Aromdee

    2009-08-01

    Full Text Available Dried pikul flower (Mimusops elengi L., Sapotaceae is used in many recipes of Thai traditional medicine i.e. cardiotonic and stomachic. In this study, fresh and dried pikul flowers were investigated. The odour of pikul flower, even when it was dried, is very strong and characteristic. The constituents of volatile oils in fresh and dried pikul flowers extracted by ether were analysed by gas chromatography-mass spectrometry. 2-Phenylethanol, 4-hydroxybenzenemethanol and cinnamyl alcohol were mainly found in fresh flower, 10.49, 8.69 and 6.17%, respectively. Whereas those mainly found in dried flowers were long chain carboxylic acid ester and (Z-9-octadecenoic acid, 5.37 and 4.71% of ether extract, respectively.An analytical method simultaneously determining benzyl alcohol, 2-phenylethanol and methyl paraben was developed by using the GC-FID method. The percent recoveries were 91.66, 104.59 and 105.28%, respectively. The intraday variations(% RSD were 7.22, 6.67 and 1.86%; and the interday variation were 3.12, 2.52 and 3.55%, respectively. Detection limits were 0.005, 0.014 and 0.001 ppm, and quantitation limits were 0.015, 0.048 and 0.003 ppm, respectively. Benzyl alcohol, 2-phenylethanol and methyl paraben content of dried flowers (9 samples from various drug stores in Thailand and one sample from China were 6.40-13.46, 17.57-196.57 and 27.35-355.53 ppm, respectively.

  7. Differential acetyl cholinesterase inhibition by volatile oils from two specimens of Marlierea racemosa (Myrtaceae) collected from different areas of the Atlantic Rain Forest.

    Science.gov (United States)

    Souza, Amanda; Silva, Michelle C; Cardoso-Lopes, Elaine M; Cordeiro, Inês; Sobral, Marcos E G; Young, Maria Cláudia M; Moreno, Paulo R H

    2009-08-01

    The volatile oil composition and anti-acetyl cholinesterase activity were analyzed in two specimens of Marlierea racemosa growing in different areas of the Atlantic Rain Forest (Cananéia and Caraguatatuba, SP, Brazil). Component identifications were performed by GC/MS and their acetyl cholinesterase inhibitory activity was measured through colorimetric analysis. The major constituent in both specimens was spathulenol (25.1% in Cananéia and 31.9% in Caraguatatuba). However, the first one also presented monoterpenes (41.2%), while in the Carguatatuba plants, this class was not detected. The oils from the plants collected in Cananéia were able to inhibit the acetyl cholinesterase activity by up to 75%, but for oils from the other locality the maximal inhibition achieved was 35%. These results suggested that the monoterpenes are more effective in the inhibition of acetyl cholinesterase activity than sesquiterpenes as these compounds are present in higher amounts in the M. racemosa plants collected in Cananéia.

  8. Recognition of beer brand based on multivariate analysis of volatile fingerprint.

    Science.gov (United States)

    Cajka, Tomas; Riddellova, Katerina; Tomaniova, Monika; Hajslova, Jana

    2010-06-18

    Automated head-space solid-phase microextraction (HS-SPME)-based sampling procedure, coupled to gas chromatography-time-of-flight mass spectrometry (GC-TOFMS), was developed and employed for obtaining of fingerprints (GC profiles) of beer volatiles. In total, 265 speciality beer samples were collected over a 1-year period with the aim to distinguish, based on analytical (profiling) data, (i) the beers labelled as Rochefort 8; (ii) a group consisting of Rochefort 6, 8, 10 beers; and (iii) Trappist beers. For the chemometric evaluation of the data, partial least squares discriminant analysis (PLS-DA), linear discriminant analysis (LDA), and artificial neural networks with multilayer perceptrons (ANN-MLP) were tested. The best prediction ability was obtained for the model that distinguished a group of Rochefort 6, 8, 10 beers from the rest of beers. In this case, all chemometric tools employed provided 100% correct classification. Slightly worse prediction abilities were achieved for the models "Trappist vs. non-Trappist beers" with the values of 93.9% (PLS-DA), 91.9% (LDA) and 97.0% (ANN-MLP) and "Rochefort 8 vs. the rest" with the values of 87.9% (PLS-DA) and 84.8% (LDA) and 93.9% (ANN-MLP). In addition to chromatographic profiling, also the potential of direct coupling of SPME (extraction/pre-concentration device) with high-resolution TOFMS employing a direct analysis in real time (DART) ion source has been demonstrated as a challenging profiling approach. Copyright (c) 2010 Elsevier B.V. All rights reserved.

  9. Analysis of volatile components in Curcuma rhizome by microemulsion electrokinetic chromatography.

    Science.gov (United States)

    Yang, Feng-Qing; Yang, Jing; Zhang, Xue-Mei; Xu, Pan; Xia, Zhi-Ning

    2013-02-01

    Volatile chemicals are a group of very important compounds in natural products. Curcuma rhizome, which contains many bioactive volatile compounds, is a traditional Chinese medicine that has long been used for the treatment of several diseases. In the present study, a microemulsion electrokinetic chromatography (MEEKC) method was developed for the analysis of four volatile components in Curcuma rhizome, including germacrone, furanodiene, curcumenol and curdione. Experimental parameters, including the pH, type and concentrations of background electrolyte, and microemulsion compositions (type and concentrations of surfactant, co-surfactant and oil phase) were intensively investigated. Finally, the primary compounds in the methanol extract of Curcuma rhizome were separated within 30 min using a running buffer composed of 2.31% w/v (80 mmol/L) sodium dodecyl sulfate (SDS), 0.91% w/v (80 mmol/L) 1-octane, 6.95% w/v (937.5 mmol/L) 1-butanol and 1.88% w/v (312.5 mmol/L) propanol in a 5-mM borate buffer (pH 8.1). The contents of the four investigated compounds were determined in the rhizome from C. phaeocaulis. The results showed that the developed MEEKC method provided an alternative tool for the analysis of volatile components, especially those of heat-sensitive compounds from natural products.

  10. Analysis of selected volatile organic compounds at background level in South Africa.

    Science.gov (United States)

    Ntsasa, Napo; Tshilongo, James; Lekoto, Goitsemang

    2017-04-01

    Volatile organic compounds (VOC) are measured globally at urban air pollution monitoring and background level at specific locations such as the Cape Point station. The urban pollution monitoring is legislated at government level; however, the background levels are scientific outputs of the World Meteorological Organisation Global Atmospheric Watch program (WMO/GAW). The Cape Point is a key station in the Southern Hemisphere which monitors greenhouse gases and halocarbons, with reported for over the past decade. The Cape Point station does not have the measurement capability VOC's currently. A joint research between the Cape Point station and the National Metrology Institute of South Africa (NMISA) objective is to perform qualitative and quantitative analysis of volatile organic compounds listed in the GAW program. NMISA is responsible for development, maintain and disseminate primary reference gas mixtures which are directly traceable to the International System of Units (SI) The results of some volatile organic compounds which where sampled in high pressure gas cylinders will be presented. The analysis of samples was performed on the gas chromatography with flame ionisation detector and mass selective detector (GC-FID/MSD) with a dedicate cryogenic pre-concentrator system. Keywords: volatile organic compounds, gas chromatography, pre-concentrator

  11. A case study: shelf-life of smoked herring fillets by volatile compounds analysis.

    Directory of Open Access Journals (Sweden)

    Cristian Bernardi

    2014-02-01

    Full Text Available Two different products of vacuum packed cold smoked herrings were analyzed at time intervals in order to evaluate the efficiency of the processing and product stability. Microbiological total counts, lactic acid bacteria, total coliforms, pH, water activity, water content, salt content (WPS were determined. Differences in hygienic conditions and salt content were found. Principal components analysis (PCA of volatile compounds determined by GC-MS analysis allowed the differentiation of the processing.

  12. Grains colonised by moulds: fungal identification and headspace analysis of produced volatile metabolites

    Directory of Open Access Journals (Sweden)

    Maria Paola Tampieri

    2010-01-01

    Full Text Available The aim of this work was to verify if the headspace analysis of fungal volatile compounds produced by some species of Fusarium can be used as a marker of mould presence on maize. Eight samples of maize (four yellow maize from North Italy and four white maize from Hungary, naturally contaminated by Fusarium and positive for the presence of fumonisins, were analyzed to detect moisture content, Aw, volatile metabolites and an enumeration of viable moulds was performed by means of a colony count technique. Headspace samples were analysed using a gas-chromatograph equipped with a capillary column TR-WAX to detect volatile metabolites of moulds. Furthermore macro and microscopic examination of the colonies was performed in order to distinguish, according to their morphology, the genera of the prevalent present moulds. Prevalent mould of eight samples was Fusarium, but other fungi, like Aspergillus, Penicillum and Mucoraceae, were observed. The metabolites produced by F.graminearum and F. moniliforme were Isobutyl-acetate, 3-Methyl-1-butanol and, only at 8 days, 3-Octanone. The incubation time can affect off flavour production in consequence of the presence of other moulds. Further studies on maize samples under different conditions are needed in order to establish the presence of moulds using the count technique and through the identification of volatile compounds.

  13. Design and Analysis of SAW Based MEMS Gas Sensor for the Detection of Volatile Organic Gases

    Directory of Open Access Journals (Sweden)

    Staline Johnson

    2014-03-01

    Full Text Available This paper portrays the design and analysis of SAW based MEMS gas sensor for the detection of volatile organic gases. The gas sensor consists of interdigitated transducers modeled on a piezoelectric substrate and covered by a thin film of polyisobutylene (PIB which acts as the sensing layer. The piezoelectric substrate material used is YZ cut Lithium Niobate (LiNbO3 and electrodes used are made of Aluminium (Al. Mass loading effect on the sensing layer is used for the detection of volatile organic gases. The design and simultions were carried out by using comsol multiphysics software based on Finite Element Method (FEM for analytical simulations. The resonant frequency of the SAW device was determined and simulations are carried out by exposing the sensor to 100 ppm of various volatile organic gases and corresponding shift in resonant frequency for various gases are determined. The reduction in the resonant frequency is used for the detection of volatile organic gases such as chloromethane, dichloromethane, trichloromethane, tetrachloroethene, carbon tetrachloride and trichloroethylene.

  14. Analysis of volatiles induced by oviposition of elm leaf beetle Xanthogaleruca luteola on Ulmus minor.

    Science.gov (United States)

    Wegener, R; Schulz, S; Meiners, T; Hadwich, K; Hilker, M

    2001-03-01

    Egg deposition of the elm leaf beetle Xanthogaleruca luteola causes the emission of volatiles from its food plant, Ulmus minor. These volatiles are exploited by the egg parasitoid, Oomyzus gallerucae, to locate its host. In contrast to other tritrophic systems, the release of volatiles is not induced by feeding but by egg deposition. Previous investigations showed that the release is systemic and can be triggered by jasmonic acid. Comparison of headspace analysis revealed similarities in the blend of volatiles emitted following egg deposition and feeding. The mixture consists of more than 40 compounds; most of the substances are terpenoids. Leaves next to those carrying eggs emit fewer compounds. When treated with jasmonic acid, leaves emit a blend that consists almost exclusively of terpenoids. Dichloromethane extracts of leaves treated with jasmonic acid were also investigated. After separation of extracts of jasmonate induced elm leaves on silica, we obtained a fraction of terpenoid hydrocarbons that was attractive to the parasitoids. This indicates that jasmonic acid stimulates the production of terpenoid hydrocarbons that convey information of egg deposition to the parasitoid.

  15. Analytical performance of three commonly used extraction methods for the gas chromatography-mass spectrometry analysis of wine volatile compounds.

    Science.gov (United States)

    Andujar-Ortiz, I; Moreno-Arribas, M V; Martín-Alvarez, P J; Pozo-Bayón, M A

    2009-10-23

    The analytical performance of three extraction procedures based on cold liquid-liquid extraction using dicloromethane (LLE), solid phase extraction (SPE) using a styrene-divinylbenzene copolymer and headspace solid phase microextraction (SPME) using a carboxen-polydimethylsiloxane coated fibre has been evaluated based on the analysis of 30 representative wine volatile compounds. From the comparison of the three procedures, LLE and SPE showed very good linearity covering a wide range of concentrations of wine volatile compounds, low detection limits, high recovery for most of the volatile compounds under study and higher sensitivity compared to the headspace-SPME procedure. The latter showed in general, poor recovery for polar volatile compounds. Despite some drawbacks associated with the LLE and SPE procedures such as the more tedious sampling treatment and the use of organic solvents, the analytical performance of both procedures showed that they are more adequate for the analysis of wine volatiles.

  16. Revisiting The Financial Volatility – Derivative Products Relationship On Euronext. Liffe Using A Frequency Domain Analysis

    OpenAIRE

    Albulescu, Claudiu Tiberiu; Daniel GOYEAU; Tiwari, Aviral Kumar

    2013-01-01

    International audience; The present paper analyse the relationship between the volume of transactions with futures equity index products and the return volatility of their underlying assets. The study addresses the case of five stock markets, members of the Euronext.liffe: London, Paris, Amsterdam, Brussels and Lisbon. We employ a frequency domain analysis, using monthly data for the period 2001.09 – 2010.06, which allows us to identify the direction of the causality between the derivatives v...

  17. Regolith and Environment Science and Oxygen and Lunar Volatile Extraction (RESOLVE): Lunar Advanced Volatile Analysis (LAVA) Integration and Testing - Evaluation of Lee Valve

    Science.gov (United States)

    Bower, Hannah; Cryderman, Kate; Captain, Janine

    2016-01-01

    The Resource Prospector (RP) mission with the Regolith and Environment Science and Oxygen and Lunar Volatile Extraction (RESOLVE) payload will prospect for water within the lunar regolith and provide a proof of concept for In-Situ Resource Utilization (ISRU) techniques, which could be used on future lunar and Martian missions. One system within the RESOLVE payload is the Lunar Advanced Volatiles Analysis (LAVA) subsystem, which consists of a Fluid Sub System (FSS) that transports volatiles to the Gas Chromatograph-Mass Spectrometer (GC-MS) instrument. In order for the FSS to transport precise and accurate amounts of volatiles to the GC-MS instrumentation, high performance valves are used within the system. The focus of this investigation is to evaluate the redesigned Lee valve. Further work is needed to continue to evaluate the Lee valve. Initial data shows that the valve could meet our requirements however further work is required to raise the TRL to an acceptable level to be included in the flight design of the system. At this time the risk is too high to change our baseline design to include these non-latching Lee solenoid valves.

  18. Gas-Chromatographic Analysis of Major Volatile Compounds Found in Traditional Fruit Brandies from Transylvania, Romania

    Directory of Open Access Journals (Sweden)

    Teodora Emilia RUSU COLDEA

    2011-11-01

    Full Text Available In the current study, the major volatile compounds from three categories of traditional fruit brandies (plum, apple and pear were characterized by gas-chromatography (GC-FID. There were collected 26 samples from different locations of Transylvania (Romania, all made by traditional technologies involving fermentation in barrels and distillation in copper stills. The major volatile compounds, besides ethanol, identified and quantified were: acetaldehyde, ethyl acetate, methanol, 1-propanol, 2-butanol, iso-butylic alcohol, alcool amyl active, iso-amylic alcohol, 1-butanol and furfural. For each type of brandy, positive but no significant correlations between methanol and furfural concentrations in plum and apple brandy were noticed. To evaluate the differences in composition regarding the geographical origin of plum brandies and to analyze the composition of plum, apple and pear brandies it has been compared the mean values (MVP, MVA and MVPe obtained for each volatile. For plum brandies it has been observed differences among the mean values of each volatile, in samples originating from counties Cluj, Bistriţa-Năsăud and Maramureş. For methanol, acetaldehyde and 1-propanol the MVP Cluj values were significantly higher than MVP Bistriţa-Năsăud. For iso-butylic alcohol, amyl active alcohol, iso-amylic alcohol the MVP Cluj values were significantly higher than for Bistriţa-Năsăud and Maramureş, while for ethyl acetate and furfural the MVP Bistriţa-Năsăud were significantly higher than MVP Cluj and MVP Maramureş. When compared the mean values of volatiles in plum vs apple vs pear brandies, for ethyl acetate, methanol, 2-butanol, 1-propanol and 1-butanol, the MVPe values were significantly higher than MVA, for furfural, amyl active and iso-amylic alcohols, while for acetaldehyde the MVPe values were significantly higher than MVP. Methanol represented the major volatile component, characteristic to fruit brandies, released by enzymatic

  19. Validation of thermodesorption method for analysis of semi-volatile organic compounds adsorbed on wafer surface.

    Science.gov (United States)

    Hayeck, Nathalie; Gligorovski, Sasho; Poulet, Irène; Wortham, Henri

    2014-05-01

    To prevent the degradation of the device characteristics it is important to detect the organic contaminants adsorbed on the wafers. In this respect, a reliable qualitative and quantitative analytical method for analysis of semi-volatile organic compounds which can adsorb on wafer surfaces is of paramount importance. Here, we present a new analytical method based on Wafer Outgassing System (WOS) coupled to Automated Thermal Desorber-Gas chromatography-Mass spectrometry (ATD-GC-MS) to identify and quantify volatile and semi-volatile organic compounds from 6", 8" and 12" wafers. WOS technique allows the desorption of organic compounds from one side of the wafers. This method was tested on three important airborne contaminants in cleanroom i.e. tris-(2-chloroethyl) phosphate (TCEP), tris-(2-chloroisopropyl) phosphate (TCPP) and diethyl phthalate (DEP). In addition, we validated this method for the analysis and quantification of DEP, TCEP and TCPP and we estimated the backside organic contamination which may contribute to the front side of the contaminated wafers. We are demonstrating that WOS/ATD-GC-MS is a suitable and highly efficient technique for desorption and quantitative analysis of organophosphorous compounds and phthalate ester which could be found on the wafer surface.

  20. Tequila volatile characterization and ethyl ester determination by solid phase microextraction gas chromatography/mass spectrometry analysis.

    Science.gov (United States)

    Vallejo-Cordoba, Belinda; González-Córdova, Aarón Fernando; del Carmen Estrada-Montoya, María

    2004-09-08

    Solid phase microextraction (SPME) and gas chromatography were used for tequila volatile characterization and ethyl ester quantitation. Several factors determined the differences in tequila volatile profiles obtained by the SPME technique, namely, sampling mode, fiber coating, and fiber exposure time. Each of these factors determined the most suitable conditions for the analysis of volatile profiles in tequila. Volatile extraction consisted of placing 40 mL of tequila in a sealed vial kept at 40 degrees C. A poly(dimethylsiloxane) fiber was immersed in the liquid for 60 min and desorbed for 5 min into the gas chromatograph. The identified volatiles by mass spectrometry were mainly alcohols, esters, and ketones. The calibration curves for ethyl hexanoate, octanoate, and decanoate followed linear relationships with highly significant (p tequila samples. Quantitative differences in ethyl esters were found for the four most commonly known tequila types: silver, gold, aged, and extra-aged.

  1. A meta-analysis approach for assessing the diversity and specificity of belowground root and microbial volatiles

    Directory of Open Access Journals (Sweden)

    Denis eSchenkel

    2015-09-01

    Full Text Available Volatile organic compounds are secondary metabolites emitted by all organisms, especially by plants and microbes. Their role as aboveground signals has been established for decades. Recent evidence suggests that they might have a non-negligible role belowground and might be involved in root-root and root-microbial/pest interactions. Our aim here was to make a comprehensive review of belowground volatile diversity using a meta-analysis approach. At first we synthesized current literature knowledge on plant root volatiles and classified them in terms of chemical diversity. In a second step, relying on the mVOC database of microbial volatiles, we classified volatiles based on their emitters (bacteria versus fungi and their specific ecological niche (i.e. rhizosphere, soil. Our results highlight similarities and differences among root and microbial volatiles and also suggest that some might be niche specific. We further explored the possibility that volatiles might be involved in intra- and inter-specific root-root communication and discuss the ecological implications of such scenario. Overall this work synthesizes current knowledge on the belowground volatilome and the potential signaling role of its constituents. It also highlights that the total diversity of belowground volatiles might be numerous orders of magnitude larger that the few hundreds of compounds described to date.

  2. Volatile Analysis by Pyrolysis of Regolith (Vapor) on the Moon using Mass Spectrometry

    Science.gov (United States)

    Glavin, D. P.; Kate, I. L. ten; Brinckerhoff, W.; Cardiff, E.; Dworkin, J. P.; Feng, S.; Getty, S.; Gorevan, S.; Harpold, D.; Jones, A. L.; King, T.; Mahaffy, P. R.; Martin, D.; Moore, M.; Roberts, D.; Robman, P.; Simmons, C.; Stephenson, T.; Swindle, T.

    2008-01-01

    The identification of lunar resources such as water is a fundamental component of the the NASA Vision for Space Exploration. The Lunar Prospector mission detected high concentrations of hydrogen at the lunar poles that may indicate the presence of water or other volatiles in the lunar regolith [1]. One explanation for the presence of enhanced hydrogen in permanently shadowed crater regions is long term trapping of water-ice delivered by comets, asteroids, and other meteoritic material that have bombarded the Moon over the last 4 billion years [2]. It is also possible that the hydrogen signal at the lunar poles is due to hydrogen implanted by the solar wind which is delayed from diffusing out of the regolith by the cold temperatures [3]. Previous measurements of the lunar atmosphere by the LACE experiment on Apollo 17, suggested the presence of cold trapped vola'tiles that were expelled by solar heating [4]. In situ composition and isotopic analyses of the lunar regolith will be required to establish the abundance, origin, and distribution of water-ice and other volatiles at the lunar poles. Volatile Analysis by Pyrolysis of Regolith (VAPoR) on the Moon using mass spectrometry is one technique that should be considered. The VAPoR pyrolysis-mass spectrometer (pyr-MS) instrument concept study was selected for funding in 2007 by the NASA Lunar Sortie Science Opportunities (LSSO) Program. VAPoR is a miniature version of the Sample Analysis at Mars (SAM) instrument suite currently being developed at NASA Goddard for the 2009 Mars Science Laboratory mission (Fig. 1).

  3. Volatile compounds analysis and antioxidant, antimicrobial and cytotoxic activities of Mindium laevigatum

    Directory of Open Access Journals (Sweden)

    Abdolrasoul Haghir Ebrahimabadi

    2016-12-01

    Full Text Available Objective(s: Mindium laevigatum is an endemic plant of Iran and Turkey and is widely used as blood purifier, antiasthma and antidyspnea in traditional medicine. Chemical composition of volatile materials of the plant and its antioxidant, antimicrobial and cytotoxic activities were reported in this study. Materials and Methods: Simultaneous distillation-extraction (SDE and GC-Mass-FID analysis were used for the plant volatile materials chemical composition identification and quantification. Several antioxidant tests including DPPH radical scavenging, hydrogen peroxide scavenging, reducing power determination, β-carotene-linoleic acid and total phenolic content tests were used for antioxidant activity evaluation. Antimicrobial and anticancer activities were also estimated using microbial strains, cancer cell lines and brine shrimp larva. Results: GC-Mass-FID analysis of volatile samples showed a total of 74 compounds of which palmitic acid (7.4-33.7%, linoleic acid (6.6-18.6%, heneicosane (1.3-9.6% and myristic acid (1.4-6.0% were detected as main volatile components. Moderate to good results were recorded for the plant in              β-carotene-linoleic acid test. Total phenolic content of the extracts as gallic acid equivalents were estimated in the range of 15.7 to 79.6 μg/mg. Some microbial strains showed moderate sensitivities to plant extracts. Brine shrimp lethality test and cytotoxic cancer cell line assays showed mild cytotoxic activities for the plant. Conclusion: Moderate to good antioxidant activities in β-carotene-linoleic acid test and presence of considerable amounts of unsaturated hydrocarbons may explain the plant traditional use in asthma and dyspnea. These findings also candidate it as a good choice for investigating its possible modern medical applications.

  4. Volatile compounds analysis and antioxidant, antimicrobial and cytotoxic activities of Mindium laevigatum

    Science.gov (United States)

    Ebrahimabadi, Abdolrasoul Haghir; Movahedpour, Mohammad Mahdi; Batooli, Hossain; Ebrahimabadi, Ebrahim Haghir; Mazoochi, Asma; Qamsari, Maryam Mobarak

    2016-01-01

    Objective(s): Mindium laevigatum is an endemic plant of Iran and Turkey and is widely used as blood purifier, antiasthma and antidyspnea in traditional medicine. Chemical composition of volatile materials of the plant and its antioxidant, antimicrobial and cytotoxic activities were reported in this study. Materials and Methods: Simultaneous distillation-extraction (SDE) and GC-Mass-FID analysis were used for the plant volatile materials chemical composition identification and quantification. Several antioxidant tests including DPPH radical scavenging, hydrogen peroxide scavenging, reducing power determination, β-carotene-linoleic acid and total phenolic content tests were used for antioxidant activity evaluation. Antimicrobial and anticancer activities were also estimated using microbial strains, cancer cell lines and brine shrimp larva. Result: s: GC-Mass-FID analysis of volatile samples showed a total of 74 compounds of which palmitic acid (7.4-33.7%), linoleic acid (6.6-18.6%), heneicosane (1.3-9.6%) and myristic acid (1.4-6.0%) were detected as main volatile components. Moderate to good results were recorded for the plant in β-carotene-linoleic acid test. Total phenolic content of the extracts as gallic acid equivalents were estimated in the range of 15.7 to 79.6 μg/mg. Some microbial strains showed moderate sensitivities to plant extracts. Brine shrimp lethality test and cytotoxic cancer cell line assays showed mild cytotoxic activities for the plant. Conclusion: Moderate to good antioxidant activities in β-carotene-linoleic acid test and presence of considerable amounts of unsaturated hydrocarbons may explain the plant traditional use in asthma and dyspnea. These findings also candidate it as a good choice for investigating its possible modern medical applications. PMID:28096967

  5. Analysis of volatile organic compounds in compost samples: A potential tool to determine appropriate composting time.

    Science.gov (United States)

    Zhu, Fengxiang; Pan, Zaifa; Hong, Chunlai; Wang, Weiping; Chen, Xiaoyang; Xue, Zhiyong; Yao, Yanlai

    2016-12-01

    Changes in volatile organic compound contents in compost samples during pig manure composting were studied using a headspace, solid-phase micro-extraction method (HS-SPME) followed by gas chromatography with mass spectrometric detection (GC/MS). Parameters affecting the SPME procedure were optimized as follows: the coating was carbon molecular sieve/polydimethylsiloxane (CAR/PDMS) fiber, the temperature was 60°C and the time was 30min. Under these conditions, 87 compounds were identified from 17 composting samples. Most of the volatile components could only be detected before day 22. However, benzenes, alkanes and alkenes increased and eventually stabilized after day 22. Phenol and acid substances, which are important factors for compost quality, were almost undetectable on day 39 in natural compost (NC) samples and on day 13 in maggot-treated compost (MC) samples. Our results indicate that the approach can be effectively used to determine the composting times by analysis of volatile substances in compost samples. An appropriate composting time not only ensures the quality of compost and reduces the loss of composting material but also reduces the generation of hazardous substances. The appropriate composting times for MC and NC were approximately 22days and 40days, respectively, during the summer in Zhejiang.

  6. Choice and use of standards for dynamic headspace trapping and application to the analysis of the volatiles of baked potato.

    Science.gov (United States)

    Ames, J M; Duckham, S C; Bakker, J

    2001-01-01

    When attempting to quantify the volatile components of a food isolated by dynamic headspace trapping onto an adsorbent, the analyst has to select the most appropriate compounds to use as standards and at which stage of the analysis to add them. Factors to be borne in mind include the volatility of the standard, the response of the GC detector, and whether to add the standard to the sample or to the adsorbent trap. This chapter considers the issues and describes the application of one chosen method to the quantitation of the volatile components of baked potato.

  7. Comparison of purge and trap GC/MS and purgeable organic chloride analysis for monitoring volatile chlorinated hydrocarbons

    Science.gov (United States)

    Barber, Larry B.; Thurman, E. Michael; Takahashi, Yoshi; Noriega, Mary C.

    1992-01-01

    A combined field and laboratory study was conducted to compare purge and trap gas chromatography/mass spectrometry (PT-GC/MS) and purgeable organic chloride (POCl) analysis for measuring volatile chlorinated hydrocarbons (VCH) in ground water. Distilled-water spike and recovery experiments using 10 VCH indicate that at concentrations greater than 1 ??g/l recovery is more than 80 percent for both methods with relative standard deviations of about 10 percent. Ground-water samples were collected from a site on Cape Cod, Massachusetts, where a shallow unconfined aquifer has been contaminated by VCH, and were analyzed by both methods. Results for PT-GC/MS and POCl analysis of the ground-water samples were not significantly different (alpha = 0.05, paired t-test analysis) and indicated little bias between the two methods. Similar conclusions about concentrations and distributions of VCH in the ground-water contamination plume were drawn from the two data sets. However, only PT-GC/MS analysis identified the individual compounds present and determined their concentrations, which was necessary for toxicological and biogeochemical evaluation of the contaminated ground water. POCl analysis was a complimentary method for use with PT-GC/MS analysis for identifying samples with VCH concentrations below the detection limit or with high VCH concentrations that require dilution. Use of POCl as a complimentary monitoring method for PT-GC/MS can result in more efficient use of analytical resources.

  8. Truck Roll Stability Data Collection and Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Stevens, SS

    2001-07-02

    The principal objective of this project was to collect and analyze vehicle and highway data that are relevant to the problem of truck rollover crashes, and in particular to the subset of rollover crashes that are caused by the driver error of entering a curve at a speed too great to allow safe completion of the turn. The data are of two sorts--vehicle dynamic performance data, and highway geometry data as revealed by vehicle behavior in normal driving. Vehicle dynamic performance data are relevant because the roll stability of a tractor trailer depends both on inherent physical characteristics of the vehicle and on the weight and distribution of the particular cargo that is being carried. Highway geometric data are relevant because the set of crashes of primary interest to this study are caused by lateral acceleration demand in a curve that exceeds the instantaneous roll stability of the vehicle. An analysis of data quality requires an evaluation of the equipment used to collect the data because the reliability and accuracy of both the equipment and the data could profoundly affect the safety of the driver and other highway users. Therefore, a concomitant objective was an evaluation of the performance of the set of data-collection equipment on the truck and trailer. The objective concerning evaluation of the equipment was accomplished, but the results were not entirely positive. Significant engineering apparently remains to be done before a reliable system can be fielded. Problems were identified with the trailer to tractor fiber optic connector used for this test. In an over-the-road environment, the communication between the trailer instrumentation and the tractor must be dependable. In addition, the computer in the truck must be able to withstand the rigors of the road. The major objective--data collection and analysis--was also accomplished. Using data collected by instruments on the truck, a ''bad-curve'' database can be generated. Using

  9. Analysis of Volatile Components of Adenosma indianum (Lour. Merr. by Steam Distillation and Headspace Solid-Phase Microextraction

    Directory of Open Access Journals (Sweden)

    Zhi Zeng

    2013-01-01

    Full Text Available The essential oil of Adenosma indianum (Lour. Merr. plays an important role in its antibacterial and antiphlogistic activities. In this work, the volatile components were extracted by steam distillation (SD and headspace solid-phase microextraction (HS-SPME and analysed by gas chromatography-mass spectrometry (GC-MS. A total of 49 volatile components were identified by GC-MS, and the major volatile components were α-limonene (20.59–35.07%, fenchone (15.79–31.81%, α-caryophyllene (6.98–10.32%, β-caryophyllene (6.98–10.19%, and piperitenone oxide (1.96–11.63%. The comparison of the volatile components from A. indianum (Lour. Merr. grown in two regions of China was reported. Also, the comparison of the volatile components by SD and HS-SPME was discussed. The results showed that the major volatile components of A. indianum (Lour. Merr. from two regions of China were similar but varied with different extraction methods. These results were indicative of the suitability of HS-SPME method for simple, rapid, and solvent-free analysis of the volatile components of the medicinal plants.

  10. Muscodor albus MOW12 an Endophyte of Piper nigrum L. (Piperaceae) Collected from North East India Produces Volatile Antimicrobials.

    Science.gov (United States)

    Banerjee, Debdulal; Pandey, Akhil; Jana, Maloy; Strobel, Gary

    2014-03-01

    Muscodor albus MOW12, an endophytic fungus isolated from Piper nigrum in Mawlong, Meghalaya, India, resembles some cultural and hyphal characteristics of previous isolates of Muscodor sp. In addition, it possesses about 99 % similarity in its ITS rDNA with other M. albus isolates and thus is nicely centered within the genetic tree to other Muscodor spp. This xylariaceae fungus effectively inhibits and kills certain plant pathogenic fungi by virtue of a mixture of volatile compounds that it produces. The majority of these compounds were identified by gas chromatography/mass spectrometry as small molecular weight esters, alcohols, and acids. The main ester components of this isolate of M. albus in its volatile mixture are acetic acid, ethyl ester; propanoic acid, 2-methyl-, methyl ester and acetic acid, 2-methylpropyl ester. This appears to be the first report of any M. albus strain from India.

  11. Detection of Pseudomonas aeruginosa in sputum headspace through volatile organic compound analysis

    Directory of Open Access Journals (Sweden)

    Goeminne Pieter C

    2012-10-01

    Full Text Available Abstract Introduction Chronic pulmonary infection is the hallmark of Cystic Fibrosis lung disease. Searching for faster and easier screening may lead to faster diagnosis and treatment of Pseudomonas aeruginosa (P. aeruginosa. Our aim was to analyze and build a model to predict the presence of P. aeruginosa in sputa. Methods Sputa from 28 bronchiectatic patients were used for bacterial culturing and analysis of volatile compounds by gas chromatography–mass spectrometry. Data analysis and model building were done by Partial Least Squares Regression Discriminant analysis (PLS-DA. Two analysis were performed: one comparing P. aeruginosa positive with negative cultures at study visit (PA model and one comparing chronic colonization according to the Leeds criteria with P. aeruginosa negative patients (PACC model. Results The PA model prediction of P. aeruginosa presence was rather poor, with a high number of false positives and false negatives. On the other hand, the PACC model was stable and explained chronic P. aeruginosa presence for 95% with 4 PLS-DA factors, with a sensitivity of 100%, a positive predictive value of 86% and a negative predictive value of 100%. Conclusion Our study shows the potential for building a prediction model for the presence of chronic P. aeruginosa based on volatiles from sputum.

  12. Volatile oil analysis of spruce galls caused by Sacchiphantes viridis Ratz.

    Directory of Open Access Journals (Sweden)

    Alicja Miszta

    2014-01-01

    Full Text Available The results of the analysis of volatile oil obtained from galls caused by Sacchiphantes viridis are presented in this paper. It was found that galls contain more oil than normal shoots. The composition of the oil obtained from galls differs significantly from that of normal shoots. The differences observed in the amount of camphene. β-pinene, myrcene, 3-carene, unidentinfied compounds 14 and 17, camphor, fenchyl alcohol, borneol and citronellol seem to be connected with the deterioration of central resin canals in the stem cortex during the development of galls and with the formation of new and very numerous canals in the bases of the differentiated gall leaves.

  13. Optimizing headspace sampling temperature and time for analysis of volatile oxidation products in fish oil

    DEFF Research Database (Denmark)

    Rørbæk, Karen; Jensen, Benny

    1997-01-01

    Headspace-gas chromatography (HS-GC), based on adsorption to Tenax GR(R), thermal desorption and GC, has been used for analysis of volatiles in fish oil. To optimize sam sampling conditions, the effect of heating the fish oil at various temperatures and times was evaluated from anisidine values (......) and HS-CC. AV indicated sample degradations at 90 degrees C but only small alterations between 60 and 75 degrees C. HS-GC showed increasing response with temperature and rime. Purging at 75 degrees C for 45 min was selected as the preferred sampling condition for oxidized fish oil....

  14. Chemical Analysis of Whale Breath Volatiles: A Case Study for Non-Invasive Field Health Diagnostics of Marine Mammals

    Directory of Open Access Journals (Sweden)

    Raquel Cumeras

    2014-09-01

    Full Text Available We explored the feasibility of collecting exhaled breath from a moribund gray whale (Eschrichtius robustus for potential non-invasive health monitoring of marine mammals. Biogenic volatile organic compound (VOC profiling is a relatively new field of research, in which the chemical composition of breath is used to non-invasively assess the health and physiological processes on-going within an animal or human. In this study, two telescopic sampling poles were designed and tested with the primary aim of collecting whale breath exhalations (WBEs. Once the WBEs were successfully collected, they were immediately transferred onto a stable matrix sorbent through a custom manifold system. A total of two large volume WBEs were successfully captured and pre-concentrated onto two Tenax®-TA traps (one exhalation per trap. The samples were then returned to the laboratory where they were analyzed using solid phase micro extraction (SPME and gas chromatography/mass spectrometry (GC/MS. A total of 70 chemicals were identified (58 positively identified in the whale breath samples. These chemicals were also matched against a database of VOCs found in humans, and 44% of chemicals found in the whale breath are also released by healthy humans. The exhaled gray whale breath showed a rich diversity of chemicals, indicating the analysis of whale breath exhalations is a promising new field of research.

  15. Determination of Volatile Organic Compounds in the Atmosphere Using Two Complementary Analysis Techniques.

    Science.gov (United States)

    Alonso, L; Durana, N; Navazo, M; García, J A; Ilardia, J L

    1999-08-01

    During a preliminary field campaign of volatile organic compound (VOC) measurements carried out in an urban area, two complementary analysis techniques were applied to establish the technical and scientific bases for a strategy to monitor and control VOCs and photochemical oxidants in the Autonomous Community of the Basque Country. Integrated sampling was conducted using Tenax sorbent tubes and laboratory analysis by gas chromatography, and grab sampling and in situ analysis also were conducted using a portable gas chromatograph. With the first technique, monocyclic aromatic hydrocarbons appeared as the compounds with the higher mean concentrations. The second technique allowed the systematic analysis of eight chlorinated and aromatic hydrocarbons. Results of comparing both techniques, as well as the additional information obtained with the second technique, are included.

  16. The analysis of volatility of gold coin price fluctuations in Iran using ARCH & VAR models

    Directory of Open Access Journals (Sweden)

    Younos Vakilolroaya

    2014-03-01

    Full Text Available The aim of this study is to investigate the changes in gold price and modeling of its return volatility and conditional variance model. The study gathers daily prices of gold coins as the dependent variable and the price of gold in world market, the price of oil in OPEC, exchange rate USD to IRR and index of Tehran Stock Exchange from March 2007 to July 2013 and using ARCH family models and VAR methods, the study analysis the data. The study first examines whether the data are stationary or not and then it reviews the household stability, Arch and Garch models. The proposed study investigates the causality among variables, selects different factors, which could be blamed of uncertainty in the coin return. The results indicate that the effect of sudden changes of standard deviation and after a 14-day period disappears and gold price goes back to its initial position. In addition, in this study we observe the so-called leverage effect in Iran’s Gold coin market, which means the good news leads to more volatility in futures market than bad news in an equal size. Finally, the result of analysis of variance implies that in the short-term, a large percentage change in uncertainty of the coin return is due to changes in the same factors and volatility of stock returns in the medium term, global gold output, oil price and exchange rate fluctuation to some extent will show the impact. In the long run, the effects of parameters are more evident.

  17. Quantitative analysis of mouse urine volatiles: in search of MHC-dependent differences.

    Directory of Open Access Journals (Sweden)

    Frank Röck

    Full Text Available Genes of the major histocompatibility complex (MHC, which play a critical role in immune recognition, influence mating preference and other social behaviors in mice. Training experiments using urine scent from mice differing only in the MHC complex, from MHC class I mutants or from knock-out mice lacking functional MHC class I molecules (beta2m-deficient, suggest that these behavioral effects are mediated by differences in MHC-dependent volatile components. In search for the physical basis of these behavioral studies, we have conducted a comparison of urinary volatiles in three sub-strains of C57BL/6 mice, a beta2m-deficient mutant lacking functional MHC class I expression and two unrelated inbred strains, using the technique of sorptive extraction with polydimethylsiloxan and subsequent analysis by gas chromatography/mass spectrometry. We show (i that qualitative differences occur between different inbred strains but not in mice with the C57BL/6 background, (ii that the individual variability in abundance in the same mouse strain is strongly component-dependent, (iii that C57BL/6 sub-strains obtained from different provenance show a higher fraction of quantitative differences than a sub-strain and its beta2m-mutant obtained from the same source and (iv that comparison of the spectra of beta2m mice and the corresponding wild type reveals no qualitative differences in close to 200 major and minor components and only minimal differences in a few substances from an ensemble of 69 selected for quantitative analysis. Our data suggest that odor is shaped by ontogenetic, environmental and genetic factors, and the gestalt of this scent may identify a mouse on the individual and population level; but, within the limits of the ensemble of components analysed, the results do not support the notion that functional MHC class I molecules influence the urinary volatile composition.

  18. Dynamic transcriptome analysis and volatile profiling of Gossypium hirsutum in response to the cotton bollworm Helicoverpa armigera.

    Science.gov (United States)

    Huang, Xin-Zheng; Chen, Jie-Yin; Xiao, Hai-Jun; Xiao, Yu-Tao; Wu, Juan; Wu, Jun-Xiang; Zhou, Jing-Jiang; Zhang, Yong-Jun; Guo, Yu-Yuan

    2015-07-07

    In response to insect herbivory, plants emit elevated levels of volatile organic compounds for direct and indirect resistance. However, little is known about the molecular and genomic basis of defense response that insect herbivory trigger in cotton plants and how defense mechanisms are orchestrated in the context of other biological processes. Here we monitored the transcriptome changes and volatile characteristics of cotton plants in response to cotton bollworm (CBW; Helicoverpa armigera) larvae infestation. Analysis of samples revealed that 1,969 transcripts were differentially expressed (log2|Ratio| ≥ 2; q ≤ 0.05) after CBW infestation. Cluster analysis identified several distinct temporal patterns of transcriptome changes. Among CBW-induced genes, those associated with indirect defense and jasmonic acid pathway were clearly over-represented, indicating that these genes play important roles in CBW-induced defenses. The gas chromatography-mass spectrometry (GC-MS) analyses revealed that CBW infestation could induce cotton plants to release volatile compounds comprised lipoxygenase-derived green leaf volatiles and a number of terpenoid volatiles. Responding to CBW larvae infestation, cotton plants undergo drastic reprogramming of the transcriptome and the volatile profile. The present results increase our knowledge about insect herbivory-induced metabolic and biochemical processes in plants, which may help improve future studies on genes governing processes.

  19. Analysis of black pepper volatiles by solid phase microextraction-gas chromatography: A comparison of terpenes profiles with hydrodistillation.

    Science.gov (United States)

    Jeleń, Henryk H; Gracka, Anna

    2015-10-30

    Solid phase microextraction (SPME) is widely used in food flavor compounds analysis in majority for profiling volatile compounds. Based on such profiles conclusions are often drawn concerning the percentage composition of volatile compounds in particular food, spices or raw materials. This paper focuses on the usefulness of SPME for the profiling of volatile compounds from spices using black pepper as an example. SPME profiles obtained in different analytical conditions were compared to the profile of pepper volatiles obtained using hydrodistillation in Clevenger apparatus. The profiles of both monoterpenes and sesquiterpenes of black pepper were highly dependent on sample weight (0.1 and 1g samples were tested), and extraction time (durations from 2 to 120min were tested), regardless of the SPME fiber used (PDMS and CAR/PDMS coatings were used). The characteristic phenomenon for extraction from dry ground pepper was the decrease of monoterpenes % share in volatiles with increasing extraction times, whereas at the same time the % contents of sesquiterpenes increased. Addition of water to ground pepper substantially changed extraction kinetics and mutual proportions of mono to sesquiterpenes compared to dry samples by minimizing changes in mono- to sesquiterpenes ratio in different extraction times. Obtained results indicate that SPME can be a fast extraction method for volatiles of black pepper. Short extraction times (2-10min) in conjunction with the fast GC analysis (2.1min) proposed here may offer fast alternative to hydrodistillation allowing black pepper terpenes characterization.

  20. Stochastic Volatility and Option Pricing in Heath-Jarrow-Morton Term Structure Analysis

    DEFF Research Database (Denmark)

    Christensen, Bent Jesper; Konaris, George; Nicolato, Elisa

    We consider a generalized Heath-Jarrow-Morton bond market model which allows both for jumps and stochastic volatility. Specifications with affine and quadratic volatility are studied and explicit option pricing formulas (in the Heston (1993) sense) are derived and implemented.......We consider a generalized Heath-Jarrow-Morton bond market model which allows both for jumps and stochastic volatility. Specifications with affine and quadratic volatility are studied and explicit option pricing formulas (in the Heston (1993) sense) are derived and implemented....

  1. Characterisation of volatile profile and sensory analysis of fresh-cut "Radicchio di Chioggia" stored in air or modified atmosphere.

    Science.gov (United States)

    Cozzolino, Rosaria; Martignetti, Antonella; Pellicano, Mario Paolo; Stocchero, Matteo; Cefola, Maria; Pace, Bernardo; De Giulio, Beatrice

    2016-02-01

    The volatile profile of two hybrids of "Radicchio di Chioggia", Corelli and Botticelli, stored in air or passive modified atmosphere (MAP) during 12 days of cold storage, was monitored by solid phase micro-extraction (SPME) GC-MS. Botticelli samples were also subjected to sensory analysis. Totally, 61 volatile organic compounds (VOCs) were identified in the headspace of radicchio samples. Principal component analysis (PCA) showed that fresh product possessed a metabolic content similar to that of the MAP samples after 5 and 8 days of storage. Projection to latent structures by partial least squares (PLS) regression analysis showed the volatiles content of the samples varied depending only on the packaging conditions. Specifically, 12 metabolites describing the time evolution and explaining the effects of the different storage conditions were highlighted. Finally, a PCA analysis revealed that VOCs profile significantly correlated with sensory attributes.

  2. SPME analysis of volatile compounds from unfermented olives subjected to thermal treatment.

    Science.gov (United States)

    Navarro, T; De Lorenzo, C; Pérez, R A

    2004-07-01

    The effect of different types of thermal treatment, designed to increase the product's shelf-life, on the volatile composition of "Campo Real" unfermented table olives, has been studied by headspace solid-phase microextraction (HS-SPME) and GC-MS analysis. Different SPME fibres were evaluated to determine their selectivity for a mixture of the main components of the different spices used in "Campo Real" olive dressing. Of the different fibres investigated, the polydimethylsiloxane/divinylbenzene (PDMS/DVB) fibre was selected for analysis of the olive brines, which contained nine main aroma components. The types of thermal treatment were sterilisation (121 degrees C, 15 min) and four pasteurisation conditions (60 degrees C or 80 degrees C each for 5 or 9 min). Pasteurisation did not lead to significant changes in the amounts of these nine volatile compounds; the 2-butanol signal was reduced by treatment at 80 degrees C. On the other hand, sterilisation of the brine resulted in an decrease in the signals from these compounds and the appearance of a new, high signal for benzaldehyde; the origin of this has not yet been determined. Results suggest that the selected pasteurisation conditions do not significantly modify the typical, and valued, aroma characteristics of "Campo Real".

  3. Politicized Collective Identity: A Social Psychological Analysis.

    Science.gov (United States)

    Simon, Bernd; Klandermans, Bert

    2001-01-01

    Develops a social psychological model of politicized collective identity that revolves around three conceptual themes (collective identity, the struggle for power, and the wider societal context of that power struggle). Discusses how collective identity has been politicized, showing that politicized collective identity has important consequences…

  4. Collection and analysis of active particles

    Energy Technology Data Exchange (ETDEWEB)

    DeLong, C.W.

    1950-01-27

    When it became apparent that particles were emanating from the stacks of the separations plants, it become important that the source, size, activity and composition of the particles be determined in order to evaluate the hazard to persons working in and neer the stack areas. The present report will give the results of radiochemical analysis of particles collected by electrostatic precipitation from ``B`` plant canyon ventilation air, not from the off-gas ventilation line. Of importance is the fact the particles analyzed consist not only of particles from the ventilation air but also, unavoidably, of rust from the iron manifold used to conduct the gases to the precipitator. This makes a determination of the activity versus weight ratio impossible, but should not invalidate the radiochemical data.

  5. Regolith and Environment Science and Oxygen and Lunar Volatile Extraction (RESOLVE): Lunar Advanced Volatile Analysis (LAVA) Capillary Fluid Dynamic Restriction Effects on Gas Chromatography

    Science.gov (United States)

    Gonzalez, Marianne; Quinn, Jacqueline; Captain, Janine; Santiago-Bond, Josephine; Starr, Stanley

    2015-01-01

    The Resource Prospector (RP) mission with the Regolith and Environment Science and Oxygen Lunar Volatile Extraction (RESOLVE) payload aims to show the presence of water in lunar regolith, and establish a proving ground for NASAs mission to Mars. One of the analysis is performed by the Lunar Advanced Volatiles Analysis (LAVA) subsystem, which consists of a fluid network that facilitates the transport of volatile samples to a gas chromatograph and mass spectrometer (GC-MS) instrument. The understanding of fluid dynamics directed from the GC to the MS is important due to the influence of flow rates and pressures that affect the accuracy of and prevent the damage to the overall GC-MS instrument. The micro-scale capillary fluid network within the GC alone has various lengths and inner-diameters; therefore, determination of pressure differentials and flow rates are difficult to model computationally, with additional complexity from the vacuum conditions in space and lack of a lunar atmosphere. A series of tests were performed on an experimental set-up of the system where the inner diameters of the GC transfer line connecting to the MS were varied. The effect on chromatography readings were also studied by applying these lines onto a GC instrument. It was found that a smaller inner diameter transfer line resulted in a lower flow rate, as well as a lower pressure differential across the thermal conductivity detector (TCD) unit of the GC and a negligible pressure drop across the mock-up capillary column. The chromatography was affected with longer retention times and broader peak integrations. It was concluded that a 0.050 mm inner diameter line still proved most suitable for the systems flow rate preferences. In addition, it was evident that this small transfer line portrayed some expense to GC signal characteristics and the wait time for steady-state operation.

  6. Research on Volatile Organic Compounds in the Mexico City Metropolitan Area (MCMA) in two campaigns collected in the Winter-2011 and Spring-2012

    Science.gov (United States)

    Magaña, M.; González-Vargas, S.; Blanco, S.; Watanabe, T.; Maeda, T.; Cardenas, B.

    2013-05-01

    Because of the importance of information on the concentration and speciation of Volatile Organic Compounds (VOC) in the atmosphere for the development of regulatory programs or emission control, is necessary to determine the type and the concentrations of reactive and toxic VOC in atmospheric air. The aim of this study is to determine the speciation and quantification of VOC in the atmospheric air of the Mexico City Metropolitan Area (MCMA), from samples obtained in November-December 2011 (cold-dry) and March-April (warm-dry). This study presents the results of characterization of VOC in ambient air in the MCMA conducted during 2011-2012. Sampling of VOC was done in two sampling campaigns: from November 17th to December 11th, 2011, and March 1st to April 6th, 2012 through collection of ambient air each six days in six liters stainless steel SUMMA canisters of 24 hours integrated samples, in three sites (Merced: commercial area with vehicular sources, Pedregal: residential area with vehicular sources and San Agustin: industrial sources with heavy traffic), in the MCMA. The analysis of samples was carried out with two chromatographic systems: 1) method equivalent to the EPA's Method TO-14, and 2) GC/MSD coupled to a preconcentrator ENTECH, for the analysis of the compounds listed in EPA method TO15. It was investigated the concentration of 111 volatile organic compounds, (ozone precursors and toxic compounds). It was found that concentrations of 23 species, constitute 80% of the total VOC concentration tested: ethane, propane, isobutane, n-butane, n-pentane, n-hexane, isopentane, methylcyclopentane, ethylene, propylene, acetylene, benzene, toluene, ethylbenzene, m/p-xylene, o-xylene, 1,2,4-trimethylbenzene, ethyl and isopropyl alcohols, acetone, 2-butanone, MTBE and ethyl acetate. Both in 2011 and 2012, the highest concentrations measured in the three sites were for compounds associated with the combustion of LPG gas: propane, n-butane. The highest concentrations of

  7. [Volatile Oil Analysis of Piper hongkongense form Different Hatbitats by GC-MS].

    Science.gov (United States)

    Cai, Yi; Xie, Feng-feng; Yan, Ping-hua; Gan, Ri-cheng; Zhu, Hua

    2015-02-01

    To analyze the volatile oil in Piper hongkongense from five different habitats. The volatile oil was analyzed by GC-MS. The volatile components oil of each sample varied significantly. Caryophyllene, α-caryophyllene and nerolidol 2 were common constituents of five samples. The volatile oil and chemical constituent contents of fresh sample were higher than that of the old sample. The volatile oil and chemical constituent contents of Piper hongkongense from different habitats have sig- nificant differences, which are affected by habitats, harvest season, storage time and so on.

  8. Secretory cavities and volatiles of Myrrhinium atropurpureum Schott var. atropurpureum (Myrtaceae): an endemic species collected in the restingas of Rio de Janeiro, Brazil.

    Science.gov (United States)

    Victório, Cristiane Pimentel; Moreira, Claudio B; Souza, Marcelo da Costa; Sato, Alice; Arruda, Rosani do Carmo de Oliveira

    2011-07-01

    In this study, we investigated the leaf anatomy and the composition of volatiles in Myrrhinium atropurpureum var. atropurpureum endemic to Rio de Janeiro restingas. Particularly, leaf secretory structures were described using light microscopy, and histochemical tests were performed from fresh leaves to localize the secondary metabolites. To observe secretory cavities, fixed leaf samples were free-hand sectioned. To evaluate lipophilic compounds and terpenoids the following reagents were employed: Sudans III and IV, Red oil O and Nile blue. Leaf volatiles were characterized by gas chromatography after hydrodistillation (HD) or simultaneous distillation-extraction (SDE). Leaf analysis showed several cavities in mesophyll that are the main sites of lipophilic and terpenoid production. Monoterpenes, which represented more than 80% of the major volatiles, were characterized mainly by alpha- and beta-pinene and 1,8-cineole. In order to provide tools for M. atropurpureum identification, the following distinguishing characteristics were revealed by the following data: 1) adaxial face clear and densely punctuated by the presence of round or ellipsoidal secretory cavities randomly distributed in the mesophyll; 2) the presence of cells overlying the upper neck cells of secretory cavities; 3) the presence of numerous paracytic stomata distributed on the abaxial leaf surface, but absent in vein regions and leaf margin; and 4) non-glandular trichomes on both leaf surfaces. Our study of the compounds produced by the secretory cavities of M. atropurpureum led us to conclude that volatile terpenoid class are the main secretory compounds and that they consist of a high concentration of monoterpenes, which may indicate the phytotherapeutic importance of this plant.

  9. Speculation and volatility spillover in the crude oil and agricultural commodity markets: A Bayesian analysis

    Energy Technology Data Exchange (ETDEWEB)

    Du Xiaodong, E-mail: xdu23@wisc.ed [Department of Agricultural and Applied Economics, University of Wisconsin-Madison, WI (United States); Yu, Cindy L., E-mail: cindyyu@iastate.ed [Department of Statistics, Iowa State University, IA (United States); Hayes, Dermot J., E-mail: dhayes@iastate.ed [Department of Economics and Department of Finance, Iowa State University, IA (United States)

    2011-05-15

    This paper assesses factors that potentially influence the volatility of crude oil prices and the possible linkage between this volatility and agricultural commodity markets. Stochastic volatility models are applied to weekly crude oil, corn, and wheat futures prices from November 1998 to January 2009. Model parameters are estimated using Bayesian Markov Chain Monte Carlo methods. Speculation, scalping, and petroleum inventories are found to be important in explaining the volatility of crude oil prices. Several properties of crude oil price dynamics are established, including mean-reversion, an asymmetry between returns and volatility, volatility clustering, and infrequent compound jumps. We find evidence of volatility spillover among crude oil, corn, and wheat markets after the fall of 2006. This can be largely explained by tightened interdependence between crude oil and these commodity markets induced by ethanol production.

  10. Personal Exposure to Mixtures of Volatile Organic Compounds: Modeling and Further Analysis of the RIOPA Data

    Science.gov (United States)

    Batterman, Stuart; Su, Feng-Chiao; Li, Shi; Mukherjee, Bhramar; Jia, Chunrong

    2015-01-01

    known to affect VOC exposures, many personal, environmental, and socioeconomic determinants remain to be identified, and the significance and applicability of the determinants reported in the literature are uncertain. To help answer these unresolved questions and overcome limitations of previous analyses, this project used several novel and powerful statistical modeling and analysis techniques and two large data sets. The overall objectives of this project were (1) to identify and characterize exposure distributions (including extreme values), (2) evaluate mixtures (including dependencies), and (3) identify determinants of VOC exposure. METHODS VOC data were drawn from two large data sets: the Relationships of Indoor, Outdoor, and Personal Air (RIOPA) study (1999–2001) and the National Health and Nutrition Examination Survey (NHANES; 1999–2000). The RIOPA study used a convenience sample to collect outdoor, indoor, and personal exposure measurements in three cities (Elizabeth, NJ; Houston, TX; Los Angeles, CA). In each city, approximately 100 households with adults and children who did not smoke were sampled twice for 18 VOCs. In addition, information about 500 variables associated with exposure was collected. The NHANES used a nationally representative sample and included personal VOC measurements for 851 participants. NHANES sampled 10 VOCs in common with RIOPA. Both studies used similar sampling methods and study periods. Specific Aim 1 To estimate and model extreme value exposures, extreme value distribution models were fitted to the top 10% and 5% of VOC exposures. Health risks were estimated for individual VOCs and for three VOC mixtures. Simulated extreme value data sets, generated for each VOC and for fitted extreme value and lognormal distributions, were compared with measured concentrations (RIOPA observations) to evaluate each model’s goodness of fit. Mixture distributions were fitted with the conventional finite mixture of normal distributions and the

  11. In situ extraction and analysis of volatiles and simple molecules in interplanetary dust particles, contaminants, and silica aerogel

    Science.gov (United States)

    Hartmetz, C. P.; Gibson, E. K., Jr.; Blanford, G. E.

    1990-01-01

    Results are presented for the analyses of eight interplanetary dust particles (IDPs) for the volatile elements H, C, N, O, and S and their molecular species, as well as of the volatiles associated with contaminants (i.e., the compounds used during the collection and curation of IDPs), which were carried out using a laser microprobe interfaced with a quadrupole mass spectrometer. It was found that the volatile species from contaminants were always present in the spectra of IDPs. Despite the contamination problems, several indigenous molecular species could be identified, including OH, CO2 or C2H4, C and CS2, CO2 along with CO (possibly indicating the presence of carbonate), H2S, SO, COS, SO2, and CS2. In some cases, the sulfur components can be attributed to aerosols; however, in one of the IDPs, the presence of H2S, SO, COS, and SO2 indicates the possible presence of elemental sulfur.

  12. Analysis of the Reinsurance Market Situation under Conditions of Volatility of the World Economy

    Directory of Open Access Journals (Sweden)

    Bozhenko Andriy S.

    2013-12-01

    Full Text Available The article conducts analysis of the modern state and prospects of further development of the reinsurance market through identification of prerequisites of establishment and systematisation of main stages of formation of this market situation. It studies main parameters of formation of the studies economic category: volume of the global market of reinsurance, factors of interaction of demand and supply; interconnection of participants of this market under conditions of volatility of the world economy. Results of the study, stated in this article, give a possibility to affirm that analysis and process of formation of the reinsurance market situation is a complex and multi-sided topic for conducting further studies. Using the obtained data, one can forecast future behaviour of the market participants when unfavourable situations occur and find the most optimal ways of their solution.

  13. Headspace GC-MS Analysis of Halogenated Volatile Organic Compounds in Aqueous Samples: An Experiment for General Chemistry Laboratory

    Science.gov (United States)

    Keller, John W.; Fabbri, Cindy E.

    2012-01-01

    Analysis of halogenated volatile organic compounds (HVOCs) by GC-MS demonstrates the use of instrumentation in the environmental analysis of pollutant molecules and enhances student understanding of stable isotopes in nature. In this experiment, students separated and identified several HVOCs that have been implicated as industrial groundwater…

  14. Pitfalls in the analysis of volatile breath biomarkers: suggested solutions and SIFT-MS quantification of single metabolites.

    Science.gov (United States)

    Smith, David; Spanel, Patrik

    2015-04-01

    The experimental challenges presented by the analysis of trace volatile organic compounds (VOCs) in exhaled breath with the objective of identifying reliable biomarkers are brought into focus. It is stressed that positive identification and accurate quantification of the VOCs are imperative if they are to be considered as discreet biomarkers. Breath sampling procedures are discussed and it is suggested that for accurate quantification on-line real time sampling and analysis is desirable. Whilst recognizing such real time analysis is not always possible and sample collection is often required, objective recognition of the pitfalls involved in this is essential. It is also emphasized that mouth-exhaled breath is always contaminated to some degree by orally generated compounds and so, when possible, analysis of nose-exhaled breath should be performed. Some difficulties in breath analysis are mitigated by the choice of analytical instrumentation used, but no single instrument can provide solutions to all the analytical challenges. Analysis and interpretation of breath analysis data, however acquired, needs to be treated circumspectly. In particular, the excessive use of statistics to treat imperfect mass spectrometry/mobility spectra should be avoided, since it can result in unjustifiable conclusions. It is should be understood that recognition of combinations of VOCs in breath that, for example, apparently describe particular cancer states, will not be taken seriously until they are replicated in other laboratories and clinics. Finally, the inhibiting notion that single biomarkers of infection and disease will not be identified and utilized clinically should be dispelled by the exemplary and widely used single biomarkers NO and H2 and now, as indicated by recent selected ion flow tube mass spectroscopy (SIFT-MS) results, triatomic hydrogen cyanide and perhaps pentane and acetic acid. Hopefully, these discoveries will provide encouragement to research workers to be

  15. Comparison of Three Methods for Extraction of Volatile Lipid Oxidation Products from Food Matrices for GC-MS Analysis

    DEFF Research Database (Denmark)

    Jacobsen, Charlotte; Yesiltas, B.; Berner, Lis

    GC based methods are often used for determination of volatile oxidation products such as pentanal and hexanal. Different extraction methods for extracting volatiles before GC analysis can be used, e.g static headspace, dynamic headspace and solid phase microextraction (SPME). Traditionally, dynamic...... headspace extraction has been performed manually. Recently, automated dynamic headspace methods have become available. This presentation will summarize the principles of the different extraction methods. Moreover, results from fish oil, oil-in-water emulsion and milk obtained with SPME, manual dynamic...... headspace or automated dynamic headspace (TDU/DHS) extraction followed by GC-MS analysis will be compared. In all cases, concentrations of volatiles were quantified by calibration curves by addition of selected standards to oil, emulsion or milk. The results show that the linearity of calibration curves...

  16. Analysis of volatile components in herbal pair Semen Persicae-Flos Carthami by GC-MS and chemometric resolution.

    Science.gov (United States)

    Fu, Jiangang; Li, Xiaoru; Lu, Hongmei; Liang, Yizeng

    2012-11-01

    Analysis of volatile components in herbal pair (HP) Semen Persicae-Flos Carthami (SP-FC) was performed by GC-MS coupled with chemometric resolution method (CRM). Furthermore, temperature-programmed retention indices were used together with mass spectra for identification of the volatile components. With the help of CRM, the two-dimensional data obtained from GC-MS instruments were resolved into a pure chromatogram and a mass spectrum of each chemical compound. By use of these methods upon two-dimensional data, 26, 49, and 59 volatile chemical components in essential oils of single herb Semen Persicae, Flos Carthami, and HP SP-FC were determined qualitatively and quantitatively, accounting for 78.42, 81.08, and 82.48% total contents of essential oil of single herb Semen Persicae, Flos Carthami, and HP SP-FC, respectively. It is shown that the accuracy of qualitative and quantitative analysis can be enhanced greatly by means of CRM. It is further demonstrated that the numbers of volatile chemical components of HP SP-FC are almost the addition of those of two single herbs, but the main volatile chemical components of the former are completely different from those of single herb Semen Persicae or Flos Carthami because of chemical reactions and physical changes occurring in the process of decocting two single herbs. This means that chemical components especially pharmacologically active compounds in the recipe might be different from those of single herbs.

  17. Forecasting volatility of SSEC in Chinese stock market using multifractal analysis

    Science.gov (United States)

    Wei, Yu; Wang, Peng

    2008-03-01

    In this paper, taking about 7 years’ high-frequency data of the Shanghai Stock Exchange Composite Index (SSEC) as an example, we propose a daily volatility measure based on the multifractal spectrum of the high-frequency price variability within a trading day. An ARFIMA model is used to depict the dynamics of this multifractal volatility (MFV) measures. The one-day ahead volatility forecasting performances of the MFV model and some other existing volatility models, such as the realized volatility model, stochastic volatility model and GARCH, are evaluated by the superior prediction ability (SPA) test. The empirical results show that under several loss functions, the MFV model obtains the best forecasting accuracy.

  18. Study of major volatiles in wines and discriminant analysis applied to classification according to region.

    Science.gov (United States)

    Huerta-Díaz-Regañon, M D; Salinas Fernández, M R; Masoud, T

    1997-12-01

    The major volatiles of eighty eight wines (white, rosè and red) from Madrid were studied. The samples came from the three districts forming the "Vinos de Madrid" DO (Denominación de Origen) region: Arganda, Navalcarnero and San Martín, and were analyzed by gas chromatography. The resulting data were treated by Stepwise Discriminant Analysis (SDA) in order to ascertain the efficacity of these compounds in classifying the wines according to their geographical origin. The results confirm that the above components were of little use in classifying the red and white wines and, although a correct classification percentage of 90.91% was obtained for the rosés when all the variables were used, this too was considered unsatisfactory.

  19. Headspace Solid-Phase Microextraction Analysis of Volatile Components in Phalaenopsis Nobby’s Pacific Sunset

    Directory of Open Access Journals (Sweden)

    Chih-Hsin Yeh

    2014-09-01

    Full Text Available Phalaenopsis is the most important economic crop in the Orchidaceae family. There are currently numerous beautiful and colorful Phalaenopsis flowers, but only a few species of Phalaenopsis have an aroma. This study reports the analysis volatile components present in P. Nobby’s Pacific Sunset by solid-phase microextraction (SPME coupled with gas chromatography (GC and gas chromatography/mass spectrometry (GC-MS. The results show that the optimal extraction conditions were obtained by using a DVB/CAR/PDMS fiber. A total of 31 compounds were identified, with the major compounds being geraniol, linalool and α-farnesene. P. Nobby’s Pacific Sunset had the highest odor concentration from 09:00 to 13:00 on the eighth day of storage. It was also found that in P. Nobby’s Pacific Sunset orchids the dorsal sepals and petals had the highest odor concentrations, whereas the column had the lowest.

  20. Methanol ice VUV photoprocessing: GC-MS analysis of volatile organic compounds

    Science.gov (United States)

    Abou Mrad, Ninette; Duvernay, Fabrice; Chiavassa, Thierry; Danger, Grégoire

    2016-05-01

    Next to water, methanol is one of the most abundant molecules in astrophysical ices. A new experimental approach is presented here for the direct monitoring via gas chromatography coupled to mass spectrometry (GC-MS) of a sublimating photoprocessed pure methanol ice. Unprecedentedly, in a same analysis, compelling evidences for the formation of 33 volatile organic compounds are provided. The latter are C1-C6 products including alcohols, aldehydes, ketones, esters, ethers and carboxylic acids. Few C3 and all C4 detected compounds have been identified for the first time. Tentative detections of few C5 and C6 compounds are also presented. GC-MS allows for the first time the direct quantification of C2-C4 photoproducts and shows that their abundances decrease with the increase of their carbon chain length. These qualitative and quantitative measurements provide important complementary results to previous experiments, and present interesting similarities with observations of sources rich in methanol.

  1. Survey analysis of volatile organics released from plastics under thermal stress

    Energy Technology Data Exchange (ETDEWEB)

    Kalman, D.A.

    1986-05-01

    Irritating or toxic vapors can be produced from plastic process materials by a variety of operations, such as injection molding, hot wire cutting, bandsawing and milling. These components typically are not reported in the combustion toxicology literature for the materials used, but rather represent the volatilization of plasticizers, unreacted monomer, mold-release agents or other additives, or lubricants. A method for the characterization of the complex mixtures that can result from thermal stressing of plastic and of relating quantitatively to process temperatures and amounts of plastic used is presented. The method utilizes both Thermo-Gravimetric analysis (TGA) and dynamic headspace GC/MS with on-column cryogenic focusing. Application to actual occupational situations is illustrated with three examples.

  2. GC-MS analysis of off-odor volatiles from irradiated pork

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The main compounds of off-odor volatiles from irradiated refrigerated vacuum-packaged pork were analyzed by gas chromatograph/mass spectrometer (GC-MS). The analytical results showed that the main compounds of off-odor volatiles were dimethyl disulfide, dimethyl sulfide, dimethyl trisulfide, S-methyl thioacetate, and methanethiol. It was proved that the off-odor volatile came from irradiated S-containing amino acid and thiamin.

  3. Stochastic Volatility and Option Pricing in Heath-Jarrow-Morton Term Structure Analysis

    DEFF Research Database (Denmark)

    Skovmand, David

    We consider a generalized Heath-Jarrow-Morton bond market model which allows both for jumps and stochastic volatility. Specifications with affine and quadratic volatility are studied and explicit option pricing formulas (in the Heston (1993) sense) are derived and implemented.......We consider a generalized Heath-Jarrow-Morton bond market model which allows both for jumps and stochastic volatility. Specifications with affine and quadratic volatility are studied and explicit option pricing formulas (in the Heston (1993) sense) are derived and implemented....

  4. Microwave Extraction of Volatiles for Mars Science and ISRU

    Science.gov (United States)

    Ethridge, Edwin C.; Kaulker, William F.

    2012-01-01

    The greatest advantage of microwave heating for volatiles extraction is that excavation can be greatly reduced. Surface support operations would be simple consisting of rovers with drilling capability for insertion of microwaves down bore holes to heat at desired depths. The rovers would also provide support to scientific instruments for volatiles analysis and for volatiles collection and storage. The process has the potential for a much lower mass and a less complex system than other in-situ processes. Microwave energy penetrates the surface heating within with subsequent sublimation of water or decomposition of volatile containing minerals. On Mars the volatiles should migrate to the surface to be captured with a cold trap. The water extraction and transport process coupled with atmospheric CO2 collection could readily lead to a propellant production process, H2O + CO2 yields CH4 + O2.

  5. Politicized collective identity. A social psychological analysis.

    Science.gov (United States)

    Simon, B; Klandermans, B

    2001-04-01

    This article develops a social psychological model of politicized collective identity that revolves around 3 conceptual triads. The 1st triad consists of collective identity, the struggle between groups for power, and the wider societal context. It is proposed that people evince politicized collective identity to the extent that they engage as self-conscious group members in a power struggle on behalf of their group knowing that it is the more inclusive societal context in which this struggle has to be fought out. Next, 3 antecedent stages leading to politicized collective identity are distinguished: awareness of shared grievances, adversarial attributions, and involvement of society at large. This sequence culminates in the final triad because the intergroup power struggle is eventually triangulated by involving society at large or representatives thereof. Consequences of politicized collective identity are discussed.

  6. Identification of volatile compounds in codfish ( Gadus) by a combination of two extraction Methods coupled with GC-MS analysis

    Science.gov (United States)

    Chang, Yufei; Hou, Hu; Li, Bafang

    2016-06-01

    Codfish is a kind of abyssal fish species with a great value in food industry. However, the flavor of codfish, especially the unpleasant odor, has caused serious problems in its processing. To accurately identify the volatile compounds in codfish, a combination of solid phase micro-extraction (SPME) method and simultaneous distillation extraction (SDE) method was used to extract the volatiles. Gas chromatography-mass spectrometry (GC-MS) along with Kovats indices (KI) and authentic standard compounds were used to identify the volatiles. The results showed that a total of 86 volatile compounds were identified in codfish, of them 24 were extracted by SDE, 69 compounds by SPME, and 10 compounds by both SDE and SPME. Seventy volatile compounds were found to have specific odors, of them 7 typical compounds contributed significantly to the flavor of codfish. Alcohols ( i.e., (E)-2-penten-1-ol and 2-octanol), esters ( i.e., ethyl butyrate and methyl geranate), aldehydes ( i.e., 2-dodecenal and pentadecanal) contributed the most to fresh flavor while nitrogen compounds, sulphur compounds, furans, as well as some ketones ( i.e., 2-hydroxy-3-pentanone) brought unpleasant odor, such as fishy and earthy odor. It was indicated that the combination of multiple extraction methods and GC-MS analysis can enhance the accuracy of identification, and provide a reference for the further study on flavor of aquatic products.

  7. Direct analysis of volatile fatty acids in marine sediment porewater by two-dimensional ion chromatography-mass spectrometry

    DEFF Research Database (Denmark)

    Glombitza, Clemens; Pedersen, Jeanette; Røy, Hans

    2014-01-01

    Volatile fatty acids (VFAs) are key intermediates in the microbial food web. However, the analysis of low concentrations of VFAs in marine porewater is hampered by interference from high concentrations of inorganic ions. Published methods often use sample pretreatment, including distillation or d...

  8. Malware Memory Analysis of the Jynx2 Linux Rootkit (Part 1): Investigating a Publicly Available Linux Rootkit Using the Volatility Memory Analysis Framework

    Science.gov (United States)

    2014-10-01

    Malware memory analysis of the Jynx2 Linux rootkit (Part 1) Investigating a publicly available Linux rootkit using the Volatility memory...nationale, 2014 DRDC-RDDC-2014-R176 i Abstract …….. This report is the second in a series that will examine Linux Volatility-specific memory...reports, some of the techniques described therein are not applicable to Linux -based analyses including data carving and anti-virus scanning. Thus

  9. Characterization of Volatile Components from Hüller Bitterer Hop Variety Using In-Tube Extraction GC-MS Analysis

    Directory of Open Access Journals (Sweden)

    Liana Claudia Salanță

    2015-05-01

    Full Text Available The composition of hop oil contributes to the aroma of beer and the essential oil profile of hop samples contains valuable information for brewers. The aim of this study was to characterize the Hüller Bitterer hop variety, during the development of hop cones, by analysis the composition of volatile oil using in-tube extraction gas chromatography–mass spectrometry (ITEX-GC–MS. The obtained results show that the ITEX-GC/MS method is suitable for the determination of volatile compounds from hop samples. A number of 60 compounds were separated and 50 of them were identified. The most important volatile compounds found in Hüller Bitterer hop variety belonging to the monoterpenes and sesquiterpenes classes are represented by: β-myrcene, β-caryophyllene and α-humulene. 

  10. Analysis of volatile components in a Chinese fish sauce,Fuzhou Yulu, by gas chromatography-mass spectrometry

    Institute of Scientific and Technical Information of China (English)

    Yuan-fan YANG; Shen-ru CHEN; Hui NI; Xing-qian YE

    2008-01-01

    Volatile components of Fuzhou Yulu, a Chinese fish sauce, were analyzed by gas chromatography-mass spectrometry (GC-MS), and two pretreatment methods, i.e., purge and trap (P&T) GC-MS and ethyl acetate extraction followed by GC-MS, were compared. P&T-GC-MS method determined 12 components, including sulfur-containing constituents (such as dimethyl disulfide), nitrogen-containing constituents (such as pyrazine derivatives), aldehydes and ketones. Ethyl ace tate extraction fol-lowed by GC-MS method detected 10 components, which were mainly volatile organic acids (such as benzenepropanoic acid) and esters. Neither of the two methods detected alcohols or trimethylamine. This study offers an important reference to determine volatile flavor components of traditional fish sauce through modem analysis methods.

  11. Brewing and volatiles analysis of three tea beers indicate a potential interaction between tea components and lager yeast.

    Science.gov (United States)

    Rong, Lei; Peng, Li-Juan; Ho, Chi-Tang; Yan, Shou-He; Meurens, Marc; Zhang, Zheng-Zhu; Li, Da-Xiang; Wan, Xiao-Chun; Bao, Guan-Hu; Gao, Xue-Ling; Ling, Tie-Jun

    2016-04-15

    Green tea, oolong tea and black tea were separately introduced to brew three kinds of tea beers. A model was designed to investigate the tea beer flavour character. Comparison of the volatiles between the sample of tea beer plus water mixture (TBW) and the sample of combination of tea infusion and normal beer (CTB) was accomplished by triangular sensory test and HS-SPME GC-MS analysis. The PCA of GC-MS data not only showed a significant difference between volatile features of each TBW and CTB group, but also suggested some key compounds to distinguish TBW from CTB. The results of GC-MS showed that the relative concentrations of many typical tea volatiles were significantly changed after the brewing process. More interestingly, the behaviour of yeast fermentation was influenced by tea components. A potential interaction between tea components and lager yeast could be suggested.

  12. Assessing the Collective Wealth of Australian Research Libraries: Measuring Overlap Using "Worldcat Collection Analysis"

    Science.gov (United States)

    Genoni, Paul; Wright, Jannette

    2010-01-01

    This paper reports the results of recent research examining the holdings of Australian research library collections recorded in the WorldCat database using OCLC WorldCat Collection Analysis software. The objectives of the research are: 1. To better understand the distribution of printed monographs amongst Australian research collections in order…

  13. Determination of volatile organic compounds pollution sources in malaysian drinking water using multivariate analysis.

    Science.gov (United States)

    Soh, Shiau-Chian; Abdullah, Md Pauzi

    2007-01-01

    A field investigation was conducted at all water treatment plants throughout 11 states and Federal Territory in Peninsular Malaysia. The sampling points in this study include treatment plant operation, service reservoir outlet and auxiliary outlet point at the water pipelines. Analysis was performed by solid phase micro-extraction technique with a 100 microm polydimethylsiloxane fibre using gas chromatography with mass spectrometry detection to analyse 54 volatile organic compounds (VOCs) of different chemical families in drinking water. The concentration of VOCs ranged from undetectable to 230.2 microg/l. Among all of the VOCs species, chloroform has the highest concentration and was detected in all drinking water samples. Average concentrations of total trihalomethanes (THMs) were almost similar among all states which were in the range of 28.4--33.0 microg/l. Apart from THMs, other abundant compounds detected were cis and trans-1,2-dichloroethylene, trichloroethylene, 1,2-dibromoethane, benzene, toluene, ethylbenzene, chlorobenzene, 1,4-dichlorobenzene and 1,2-dichloro - benzene. Principal component analysis (PCA) with the aid of varimax rotation, and parallel factor analysis (PARAFAC) method were used to statistically verify the correlation between VOCs and the source of pollution. The multivariate analysis pointed out that the maintenance of auxiliary pipelines in the distribution systems is vital as it can become significant point source pollution to Malaysian drinking water.

  14. Detection of Sepsis in Preterm Infants by Fecal Volatile Organic Compounds Analysis: A Proof of Principle Study.

    Science.gov (United States)

    Berkhout, Daniel J C; Niemarkt, Hendrik J; Buijck, Martin; van Weissenbruch, Mirjam M; Brinkman, Paul; Benninga, Marc A; van Kaam, Anton H; Kramer, Boris W; Andriessen, Peter; de Boer, Nanne K H; de Meij, Tim G J

    2017-09-01

    Several studies associated altered gut microbiota composition in preterm infants with late-onset sepsis (LOS), up to days before clinical onset of sepsis. Microbiota analysis as early diagnostic biomarker is, however, in clinical practice currently not feasible because of logistic aspects and high costs. Therefore, we hypothesized that analysis of fecal volatile organic compounds (VOCs) may serve as noninvasive biomarker to predict LOS at a preclinical stage, because VOC reflect the composition and activity of intestinal microbial communities. In a prospective multicenter study, fecal samples were collected daily from infants with a gestational age of <30 weeks. VOC signatures of fecal samples from infants with LOS, collected up to 5 days before diagnosis, were analyzed by means of an electronic nose technology (Cyranose 320) and compared to matched controls. Fecal VOC profiles of infants with LOS (n = 36) could be discriminated from controls (n = 40) at 3 days (area under the curve [±95% confidence interval], P value, sensitivity, specificity; 70.2 [52.2-88.3], 0.033, 57.1%, 61.5%), 2 days (77.7 [62.7-92.7], 0.050, 75.0%, 70.8%), and 1 day (70.4 [49.6-91.3], 0.037, 64.3%, 64.3%) before the onset of LOS. Fecal VOC profiles of preterm infants with LOS could be discriminated from matched controls, up to 3 days before clinical onset of the disease, underlining the hypothesis that intestinal microbiota may play an etiological role in LOS. Notably, VOC profiling is clinically feasible and the potential of this technique in the early detection of LOS needs to be confirmed in future studies.

  15. Volatility Discovery

    DEFF Research Database (Denmark)

    Dias, Gustavo Fruet; Scherrer, Cristina; Papailias, Fotis

    The price discovery literature investigates how homogenous securities traded on different markets incorporate information into prices. We take this literature one step further and investigate how these markets contribute to stochastic volatility (volatility discovery). We formally show...... that the realized measures from homogenous securities share a fractional stochastic trend, which is a combination of the price and volatility discovery measures. Furthermore, we show that volatility discovery is associated with the way that market participants process information arrival (market sensitivity...

  16. Gas chromatography-olfactometry analysis of the volatile compounds of two commercial Irish beef meats

    NARCIS (Netherlands)

    Machiels, D.; Ruth, van S.M.; Posthumus, M.A.; Istasse, L.

    2003-01-01

    The volatile flavour compounds of two commercial Irish beef meats (labelled as conventional and organic) were evaluated by gas chromatography-olfactometry and were identified by gas chromatography-mass spectrometry. The volatile compounds were isolated in a model mouth system. Gas

  17. The restoration of the gold standard after the US Civil War : A volatility analysis

    NARCIS (Netherlands)

    Meulemann, Max; Uebele, Martin; Wilfling, Bernd

    2014-01-01

    This paper presents a new view on the gold price of greenbacks during and after the American Civil War by analyzing exchange-rate volatility rather than exchange-rate levels. Our empirical investigation detects regimes of high and low volatility alternating in a way that is consistent with a theoret

  18. Gas chromatography-olfactometry analysis of the volatile compounds of two commercial Irish beef meats

    NARCIS (Netherlands)

    Machiels, D.; Ruth, van S.M.; Posthumus, M.A.; Istasse, L.

    2003-01-01

    The volatile flavour compounds of two commercial Irish beef meats (labelled as conventional and organic) were evaluated by gas chromatography-olfactometry and were identified by gas chromatography-mass spectrometry. The volatile compounds were isolated in a model mouth system. Gas chromatography-olf

  19. Volatile Organic Compound (VOC) Analysis For Disease Detection: Proof Of Principle For Field Studies Detecting Paratuberculosis And Brucellosis

    Science.gov (United States)

    Knobloch, Henri; Köhler, Heike; Nicola, Commander; Reinhold, Petra; Turner, Claire; Chambers, Mark

    2009-05-01

    A proof of concept investigation was performed to demonstrate that two independent infectious diseases of cattle result in different patterns of volatile organic compounds (VOC) in the headspace of serum samples detectable using an electronic nose (e-nose). A total of 117 sera from cattle naturally infected with Mycobacterium avium subsp. paratuberculosis (paraTB, n = 43) or Brucella sp. (n = 26) and sera from corresponding control animals (n = 48) were randomly and analysed blind to infection status using a ST214 e-nose (Scensive Ltd, Leeds, UK). Samples were collected under non-standardised conditions on different farms from the UK (brucellosis) and Germany (paraTB). The e-nose could differentiate the sera from brucellosis infected, paraTB infected and healthy animals at the population level, but the technology used was not suitable for determination of the disease status of individual animals. Nevertheless, the data indicate that there are differences in the sensor responses depending on the disease status, and therefore, it shows the potential of VOC analysis from serum headspace samples for disease detection.

  20. Solvent-based dissolution method to sample gas-phase volatile organic compounds for compound-specific isotope analysis.

    Science.gov (United States)

    Bouchard, Daniel; Hunkeler, Daniel

    2014-01-17

    An investigation was carried out to develop a simple and efficient method to collect vapour samples for compound specific isotope analysis (CSIA) by bubbling vapours through an organic solvent (methanol or ethanol). The compounds tested were benzene and trichloroethylene (TCE). The dissolution efficiency was tested for different air volume injections, using flow rates ranging from 25ml/min to 150ml/min and injection periods varying between 10 and 40min. Based on the results, complete mass recovery for benzene and TCE in both solvents was observed for the flow rates of 25 and 50ml/min. However, small mass loss was observed at increased flow rate. At 150ml/min, recovery was on average 80±17% for benzene and 84±10% for TCE, respectively in methanol and ethanol. The δ(13)C data measured for benzene and TCE dissolved in both solvents were reproducible and were stable independently of the volume of air injected (up to 6L) or the flow rate used. The stability of δ(13)C values hence underlines no isotopic fractionation due to compound-solvent interaction or mass loss. The development of a novel and simple field sampling technique undertaken in this study will facilitate the application of CSIA to diverse gas-phase volatile organic compound studies, such as atmospheric emissions, soil gas or vapour intrusion.

  1. Analysis of volatile nanoparticles emitted from diesel engine using TOF-SIMS and metal-assisted SIMS (MetA-SIMS)

    Science.gov (United States)

    Inoue, Masae; Murase, Atsushi; Yamamoto, Masami; Kubo, Shuichi

    2006-07-01

    Time-of-flight secondary ion mass spectrometry (TOF-SIMS) and metal-assisted SIMS (MetA-SIMS), which is TOF-SIMS analysis of metal-deposited sample surfaces, were applied to analyze small quantities of volatile nanoparticles emitted from a light-duty diesel engine under idling and deceleration conditions. We investigated nucleation materials, i.e., >C35 hydrocarbons, oxidation products, etc., which have lower volatility than the main components of volatile nanoparticles and control the formation of volatile nanoparticles. Oxygenated hydrocarbons were detected by TOF-SIMS in volatile nanoparticles under idling condition. Their relative intensities increased as particle diameter decreased. This resulted in the oxygenated hydrocarbons acting as nucleation materials for volatile nanoparticles under idling condition. High-molecular-weight hydrocarbons of greater than C35 were detected in volatile nanoparticles under deceleration condition by MetA-SIMS. It was concluded that the detected hydrocarbons originated in lubricants and acted as nucleation materials for volatile nanoparticles under deceleration condition. TOF-SIMS makes it possible to detect traces of low-volatility molecules due to its high-vacuum environment. MetA-SIMS is the only method of directly detecting high-molecular-weight hydrocarbons in small quantities of nanoparticles. TOF-SIMS and MetA-SIMS were proved to be useful tools for analyzing of the properties of volatile nanoparticles.

  2. Gas purge microsyringe extraction for quantitative direct gas chromatographic-mass spectrometric analysis of volatile and semivolatile chemicals.

    Science.gov (United States)

    Yang, Cui; Piao, Xiangfan; Qiu, Jinxue; Wang, Xiaoping; Ren, Chunyan; Li, Donghao

    2011-03-25

    Sample pretreatment before chromatographic analysis is the most time consuming and error prone part of analytical procedures, yet it is a key factor in the final success of the analysis. A quantitative and fast liquid phase microextraction technique termed as gas purge microsyringe extraction (GP-MSE) has been developed for simultaneous direct gas chromatography-mass spectrometry (GC-MS) analysis of volatile and semivolatile chemicals without cleanup process. Use of a gas flowing system, temperature control and a conventional microsyringe greatly increased the surface area of the liquid phase micro solvent, and led to quantitative recoveries of both volatile and semivolatile chemicals within short extraction time of only 2 min. Recoveries of polycyclic aromatic hydrocarbons (PAHs), organochlorine pesticides (OCPs) and alkylphenols (APs) determined were 85-107%, and reproducibility was between 2.8% and 8.5%. In particular, the technique shows high sensitivity for semivolatile chemicals which is difficult to achieve in other sample pretreatment techniques such as headspace-liquid phase microextraction. The variables affecting extraction efficiency such as gas flow rate, extraction time, extracting solvent type, temperature of sample and extracting solvent were investigated. Finally, the technique was evaluated to determine PAHs, APs and OCPs from plant and soil samples. The experimental results demonstrated that the technique is economic, sensitive to both volatile and semivolatile chemicals, is fast, simple to operate, and allows quantitative extraction. On-site monitoring of volatile and semivolatile chemicals is now possible using this technique due to the simplification and speed of sample treatment.

  3. Feature extraction techniques using multivariate analysis for identification of lung cancer volatile organic compounds

    Science.gov (United States)

    Thriumani, Reena; Zakaria, Ammar; Hashim, Yumi Zuhanis Has-Yun; Helmy, Khaled Mohamed; Omar, Mohammad Iqbal; Jeffree, Amanina; Adom, Abdul Hamid; Shakaff, Ali Yeon Md; Kamarudin, Latifah Munirah

    2017-03-01

    In this experiment, three different cell cultures (A549, WI38VA13 and MCF7) and blank medium (without cells) as a control were used. The electronic nose (E-Nose) was used to sniff the headspace of cultured cells and the data were recorded. After data pre-processing, two different features were extracted by taking into consideration of both steady state and the transient information. The extracted data are then being processed by multivariate analysis, Linear Discriminant Analysis (LDA) to provide visualization of the clustering vector information in multi-sensor space. The Probabilistic Neural Network (PNN) classifier was used to test the performance of the E-Nose on determining the volatile organic compounds (VOCs) of lung cancer cell line. The LDA data projection was able to differentiate between the lung cancer cell samples and other samples (breast cancer, normal cell and blank medium) effectively. The features extracted from the steady state response reached 100% of classification rate while the transient response with the aid of LDA dimension reduction methods produced 100% classification performance using PNN classifier with a spread value of 0.1. The results also show that E-Nose application is a promising technique to be applied to real patients in further work and the aid of Multivariate Analysis; it is able to be the alternative to the current lung cancer diagnostic methods.

  4. 烟草中挥发性、半挥发性酸性成分的分析%Study on the analysis of the volatile and semi-volatile acidic components in tobacco

    Institute of Scientific and Technical Information of China (English)

    贾春晓; 曲志刚; 毛多斌; 王志韬; 张文叶

    2003-01-01

    A new method was developed for the analysis of the volatile and semi-volatile acidic components in tobacco by gas chromatography-mass spectrometry selected ion monitoring (GC-MS, SIM)method. The acidic components in tobacco samples were extracted by methylene chloride using simultaneous distillation and extraction equipment, and they were analyzed by HP-INNOWAX column (30m × 250μm × 0.25μm ). Thirteen acidic components were quantitatively determined by internal standard curve method. The experiment results showed that the added standard recoveries of the acidic components were in the range from 80.6% to 98.8%, the relative standard deviations(RSD)were less than 2.0% and the correlation coeflqcients were more than 0.99. The method is simple, rapid and accurate for the determination of the volatile and semi-volatile acidic components in tobacco.

  5. Color and volatile analysis of peanuts roasted using oven and microwave technologies.

    Science.gov (United States)

    Smith, Alicia L; Barringer, Sheryl A

    2014-10-01

    Roasted peanut color and volatiles were evaluated for different time and temperature combinations of roasting. Raw peanuts were oven roasted at 135 to 204 °C, microwave roasted for 1 to 3 min, or combination roasted by microwave and oven roasting for various times and temperatures. Volatiles were measured using selected ion flow tube mass spectrometry. L* values were used to categorize peanuts as under-roasted, ideally roasted, and over-roasted. The total roasting time in order to achieve ideal color was not shortened by most of the combination treatments compared to their oven roasted equivalents. Oven before microwave roasting compared to the reverse was found to significantly increase the L* value. Peanuts with the same color had different volatile levels. Hexanal concentrations decreased then increased with roasting. Pyrazine levels increased as roasting time increased, although oven at 177 °C treatments had the highest and microwave treatments had the lowest levels. Volatile levels generally increased as roasting time or temperature increased. Oven 177 °C for 15 min generally had the highest level of volatiles among the roasting treatments tested. Soft independent modeling of class analogies based on volatile levels showed that raw peanuts were the most different, commercial samples were the most similar to each other, and oven, microwave, and combination roasting were all similar in volatile profile. Peanuts can be roasted to equivalent colors and have similar volatile levels by different roasting methods. Oven and microwave roasting technologies produced the same roasted peanut color and had similar volatile trends as roasting time increased. Combination roasting also produced ideal color and similar volatile levels indicating that microwave technology could be further explored as a peanut roasting technique. © 2014 Institute of Food Technologists®

  6. Analysis of luwak coffee volatile by using solid phase microextraction and gas chromatography (Analisa senyawa volatil kopi luwak dengan menggunakan mikroekstrasi fase padat dan kromatolgi gas.

    Directory of Open Access Journals (Sweden)

    Ariza Budi Tunjung Sari

    2012-08-01

    Full Text Available The approach to authenticate Luwak coffee is made through analysis of volatile compounds of luwak coffee. Luwak coffee bean from type of arabica obtained from Andungsari Plantation in Bondowoso district, East Java Province Indonesia, was wet processed and sundried prior to roasting step. As many as 120 g green bean was roasted at 170-220°C for 8-12 minutes until reached light brown colour (Agtron scale 65 and was ground prior to extraction. Volatile compounds of roasted Luwak arabica coffee bean were extracted by using solid phase microextraction (SPME at 60°C for 30 minutes. The extracted analyte was subsequently transferred into GC-FID system by splitless injection at 260°C with five minutes sampling time, continued with separation through 50% phenyl 50% dimethylpolysiloxane capillary column and oven temperature programmed from 60°C to 180°C with rate of 5°C/min. Resulted chromatogram shows major peaks mainly in Rt 8.360-9.981, and Rt 9.705-14.778, and minor peaks identified before Rt 10 and after Rt 24. Varied sample quantity ranged within 0.5-2.5 g produced chromatograms which were not significantly different (p=0.08. This research also observed the use of γ-picoline (4-methylpyridine as internal standard. It was showed that γ-picoline appeared at Rt 8.6~ without overlaying other peaks originated from sample. Concentration of γ-picoline at 0.05 μL/g, resulted separable peaks. These findings showed that the use of solid phase microextraction and GC-FID is capable to be apply for identification and quantification of Luwak coffee

  7. Training course 'Fisheries data collection and analysis'

    NARCIS (Netherlands)

    Heijden, van der P.G.M.

    2007-01-01

    Course description of the course “Fisheries data collection and analysis”, held from October 1st till October 19th 2007 and organised by the Programme for Capacity development & Institutional Change of Wageningen International in cooperation with Wageningen University – Aquaculture and Fisheries

  8. Characterization of Botanical and Geographical Origin of Corsican “Spring” Honeys by Melissopalynological and Volatile Analysis

    Directory of Open Access Journals (Sweden)

    Yin Yang

    2014-01-01

    Full Text Available Pollen spectrum, physicochemical parameters and volatile fraction of Corsican “spring” honeys were investigated with the aim of developing a multidisciplinary method for the qualification of honeys in which nectar resources are under-represented in the pollen spectrum. Forty-one Corsican “spring” honeys were certified by melissopalynological analysis using directory and biogeographical origin of 50 representative taxa. Two groups of honeys were distinguished according to the botanical origin of samples: “clementine” honeys characterized by the association of cultivated species from oriental plain and other “spring” honeys dominated by wild herbaceous taxa from the ruderal and/or maquis area. The main compounds of the “spring” honey volatile fraction were phenylacetaldehyde, benzaldehyde and methyl-benzene. The volatile composition of “clementine” honeys was also characterized by three lilac aldehyde isomers. Statistical analysis of melissopalynological, physicochemical and volatile data showed that the presence of Citrus pollen in “clementine” honeys was positively correlated with the amount of linalool derivatives and methyl anthranilate. Otherwise, the other “spring” honeys were characterized by complex nectariferous species associations and the content of phenylacetaldehyde and methyl syringate.

  9. 78 FR 38096 - Fatality Analysis Reporting System Information Collection

    Science.gov (United States)

    2013-06-25

    ... Number NHTSA-2012-0168] Fatality Analysis Reporting System Information Collection AGENCY: National... comments on the following proposed collections of information: (1) Title: Fatal Analysis Reporting System... damage associated with motor vehicle accidents. The Fatality Analysis Reporting System (FARS) is a major...

  10. Analysis of Pyrazine and Volatile Compounds in Cocoa Beans Using Solid Phase Microextraction

    Directory of Open Access Journals (Sweden)

    Misnawi Jati

    2011-05-01

    Full Text Available Analisis pirazin dan senyawa volatil pada biji kakao dilakukan dengan perangkat mikroekstraksi fase padat (solid phase micro extraction, SPME, untuk mengembangkan metode ekstraksi tanpa pelarut yang efisien. Perangkat SPME dilengkapi fiber stableflex dengan polimer DVB/Carboxen/PDMS yang menjerap senyawa volatil di area headspace. Biji kakao terfermentasi disangrai dan diambil lemaknya untuk ditempatkan dalam botol bertutup septa. Sampel dipanaskan pada suhu 70OC dan serat SPME ditusukkan menembus septa untuk mengekstrak senyawa volatil dari lemak kakao selama 30 menit. Senyawa volatil lemak kakao akan dijerap oleh serat SPME dan dilepaskan kembali untuk analisis kromatografi gas. Penelitian menunjukkan pirazin dan senyawa volatil yang diekstrak oleh serat SPME dapat terdeteksi dengan baik oleh kromatografi gas. Area puncak yang dihasilkan SPME meliputi 2,83–5,35% dari area puncak yang dihasilkan syringe, kendati demikian kemampuan ekstraksi SPME dapat disetarakan dengan syringe. Lima jenis pirazin yang sering terdapat di biji kakao telah diidentifikasi, meliputi metil pirazin (2MP; 2,3 dan 2,5-dimetilpirazin (DMP; dan 2,3,5 trimetilpirazin (TrMP dan tetrametil pirazin (TMP. Senyawa lainnya juga terdeteksi meliputi alkohol, asam karboksilat, aldehida, keton, ester, pirazin, amin dan senyawa volatil lainnya, dan diketahui erat kaitannya dengan aroma khas cokelat. Keberhasilan SPME dalam ekstraksi pirazin dan senyawa volatilsemi volatil yang berperan penting dalam pembentukan aroma cokelat menandakan SPME dapat digunakan lebih lanjut untuk analisis citarasa.

  11. Analysis of the build-up of semi and non volatile organic compounds on urban roads.

    Science.gov (United States)

    Mahbub, Parvez; Ayoko, Godwin A; Goonetilleke, Ashantha; Egodawatta, Prasanna

    2011-04-01

    Vehicular traffic in urban areas may adversely affect urban water quality through the build-up of traffic generated semi and non volatile organic compounds (SVOCs and NVOCs) on road surfaces. The characterisation of the build-up processes is the key to developing mitigation measures for the removal of such pollutants from urban stormwater. An in-depth analysis of the build-up of SVOCs and NVOCs was undertaken in the Gold Coast region in Australia. Principal Component Analysis (PCA) and Multicriteria Decision tools such as PROMETHEE and GAIA were employed to understand the SVOC and NVOC build-up under combined traffic scenarios of low, moderate, and high traffic in different land uses. It was found that congestion in the commercial areas and use of lubricants and motor oils in the industrial areas were the main sources of SVOCs and NVOCs on urban roads, respectively. The contribution from residential areas to the build-up of such pollutants was hardly noticeable. It was also revealed through this investigation that the target SVOCs and NVOCs were mainly attached to particulate fractions of 75-300 μm whilst the redistribution of coarse fractions due to vehicle activity mainly occurred in the >300 μm size range. Lastly, under combined traffic scenario, moderate traffic with average daily traffic ranging from 2300 to 5900 and average congestion of 0.47 were found to dominate SVOC and NVOC build-up on roads.

  12. Collective effects analysis for the Berkeley femtosource

    Energy Technology Data Exchange (ETDEWEB)

    Corlett, J.; De Santis, S.; Wolski, A.; Zholents, A.

    2003-05-01

    We present an overview of the collective effects in a proposed ultrafast x-ray facility, based on a recirculating linac. The facility requires a small vertical ewmittance of 0.4 mm-mrad and is designed to operate with a ''flat bunch'' with a large aspect ratio of emittances. Emittance control from the electron source at the RF photocathode to the photon production chain of undulators, and understanding and the mitigation of collective effects is critical to a successful machine operation. Key aspects of accelerator physics involved in beam break-up, coherent synchrotron radiation, resistive wall impedance and other effects have been addressed and reported here.

  13. Direct Analysis of Volatile Organic Compounds in Foods by Headspace Extraction Atmospheric Pressure Chemical Ionisation Mass Spectrometry.

    Science.gov (United States)

    Perez-Hurtado, P; Palmer, E; Owen, T; Aldcroft, C; Allen, M H; Jones, J; Creaser, C S; Lindley, M R; Turner, M A; Reynolds, J C

    2017-08-30

    The rapid screening of volatile organic compounds (VOCs) by direct analysis has potential applications in the areas of food and flavour science. Currently the technique of choice for VOC analysis is gas chromatography-mass spectrometry (GC/MS). However, the long chromatographic run times and elaborate sample preparation associated with this technique have led a movement towards direct analysis techniques, such as selected ion flow tube mass spectrometry (SIFT-MS), proton transfer reaction mass spectrometry (PTR-MS) and electronic noses. The work presented here describes the design and construction of a Venturi jet-pump based modification for a compact mass spectrometer which enables the direct introduction of volatiles for qualitative and quantitative analysis. Volatile organic compounds were extracted from the headspace of heated vials into the atmospheric pressure chemical ionization source of a quadrupole mass spectrometer using a Venturi pump. Samples were analysed directly with no prior sample preparation. Principal component analysis was used to differentiate between different classes of samples RESULTS: The interface is shown to be able to routinely detect problem analytes such as fatty acids and biogenic amines without the requirement of a derivatisation step, and is shown to be able to discriminate between four different varieties of cheese with good intra and inter-day reproducibility using an unsupervised principal component analysis model. Quantitative analysis is demonstrated using indole standards with limits of detection and quantification of 0.395 μg/mL and 1.316 μg/mL, respectively. The described methodology can routinely detect highly reactive analytes such as volatile fatty acids and diamines without the need for a derivatisation step or lengthy chromatographic separations. The capability of the system was demonstrated by discriminating between different varieties of cheese and monitoring the spoilage of meats. This article is protected by

  14. Analysis of volatile compounds in exhaled breath condensate in patients with severe pulmonary arterial hypertension.

    Directory of Open Access Journals (Sweden)

    J K Mansoor

    Full Text Available BACKGROUND: An important challenge to pulmonary arterial hypertension (PAH diagnosis and treatment is early detection of occult pulmonary vascular pathology. Symptoms are frequently confused with other disease entities that lead to inappropriate interventions and allow for progression to advanced states of disease. There is a significant need to develop new markers for early disease detection and management of PAH. METHODOLGY AND FINDINGS: Exhaled breath condensate (EBC samples were compared from 30 age-matched normal healthy individuals and 27 New York Heart Association functional class III and IV idiopathic pulmonary arterial hypertenion (IPAH patients, a subgroup of PAH. Volatile organic compounds (VOC in EBC samples were analyzed using gas chromatography/mass spectrometry (GC/MS. Individual peaks in GC profiles were identified in both groups and correlated with pulmonary hemodynamic and clinical endpoints in the IPAH group. Additionally, GC/MS data were analyzed using autoregression followed by partial least squares regression (AR/PLSR analysis to discriminate between the IPAH and control groups. After correcting for medicaitons, there were 62 unique compounds in the control group, 32 unique compounds in the IPAH group, and 14 in-common compounds between groups. Peak-by-peak analysis of GC profiles of IPAH group EBC samples identified 6 compounds significantly correlated with pulmonary hemodynamic variables important in IPAH diagnosis. AR/PLSR analysis of GC/MS data resulted in a distinct and identifiable metabolic signature for IPAH patients. CONCLUSIONS: These findings indicate the utility of EBC VOC analysis to discriminate between severe IPAH and a healthy population; additionally, we identified potential novel biomarkers that correlated with IPAH pulmonary hemodynamic variables that may be important in screening for less severe forms IPAH.

  15. Headspace solvent microextraction-gas chromatography-mass spectrometry for the analysis of volatile compounds from Foeniculum vulgare Mill.

    Science.gov (United States)

    Fang, Lianghua; Qi, Meiling; Li, Ting; Shao, Qinglong; Fu, Ruonong

    2006-06-07

    A novel and rapid headspace solvent microextraction followed by gas chromatography-mass spectrometry (HSME-GC-MS) for the analysis of the volatile compounds of Foeniculum vulgare Mill is described. HSME parameters including extracting solvent, extraction temperature and time, headspace volume and particle size were optimized. As a result, benzyl alcohol was finally used for the extraction at 70 degrees C for 20 min with headspace volume of 12.1 ml and particle size of 120 mesh. Under the determined conditions, the powered samples of Foeniculum vulgare Mill were directly applied for the analysis. A comparison of HSME-GC-MS, solid phase microextraction (SPME)-GC-MS and steam distillation (SD)-GC-MS methods was made and showed that the HSME-GC-MS method was simple, inexpensive and effective and can be used for the analysis of volatile compounds in traditional Chinese medicines (TCMs).

  16. Numerical modeling and experimental analysis of volatile contaminant removal from vertical flow filters

    NARCIS (Netherlands)

    De Biase, C.

    2012-01-01

    Vertical flow filters (unplanted) and vertical flow constructed wetlands (planted), simple and inexpensive technologies to treat effectively volatile organic compounds (VOCs) contaminated water, consist of containers filled with granular material which is intermittently fed with contaminated water.

  17. MANAGING EXCHANGE RATE VOLATILITY : A COMPARATIVE COUNTERFACTUAL ANALYSIS OF SINGAPORE 1994 TO 2003

    OpenAIRE

    Peter Wilson; Henry Ng Shang Ren

    2006-01-01

    The objective of this paper is see how well Singapore’s exchange rate regime has coped with exchange rate volatility before and after the Asian financial crisis by comparing the performance of Singapore’s actual regime in minimising the volatility of the nominal effective exchange rate (NEER) and the bilateral rate against the US$ against some counterfactual regimes and the corresponding performance of eight other East Asian countries. In contrast to previous counterfactual exercises, such as...

  18. Volatility and covariation of financial assets: a high-frequency analysis

    OpenAIRE

    Cartea, Alvaro; Karyampas, Dimitrios

    2009-01-01

    Using high frequency data for the price dynamics of equities we measure the impact that market microstructure noise has on estimates of the: (i) volatility of returns; and (ii) variance-covariance matrix of n assets. We propose a Kalman-filter-based methodology that allows us to deconstruct price series into the true efficient price and the microstructure noise. This approach allows us to employ volatility estimators that achieve very low Root Mean Squared Errors (RMSEs) compared to other est...

  19. Quantitative Analysis of Volatile Impurities in Diallyldimethylammonium Chloride Monomer Solution by Gas Chromatography Coupled with Liquid-Liquid Extraction

    Directory of Open Access Journals (Sweden)

    Cheng Liu

    2017-01-01

    Full Text Available The quantitative analysis method for volatile impurities in diallyldimethylammonium chloride (DADMAC monomer solution was established in this paper. The volatile impurities were quantitatively analyzed with trichloromethane as extraction solvent and n-hexane as internal standard by using gas chromatography (GC coupled with solvent extraction, and the chromatographic conditions, quantitative methods, and extraction conditions were systematically investigated in detail. The results showed that excellent linear relationships of 5 volatile impurities (dimethylamine, allyldimethylamine, allyl chloride, allyl alcohol, and allyl aldehyde were obtained in the range of 1–100 mg·L−1. The method also showed good specificity, recovery (95.0%–107.5%, and relative standard deviation (RSD, 1.40%–7.67%. This method could accurately detect the whole volatile impurities in DADMAC monomer solution quantitatively in one time with a low detection limit. Furthermore, this method is conducive to the preparation of highly pure DADMAC monomer and the development of national and international standards of the DADMAC monomer product quality, and the results could provide a strong foundation for the regulation and mechanism research of impurities on monomer reactivity in polymerization.

  20. Analysis of volatile compounds of Malaysian Tualang (Koompassia excelsa) honey using gas chromatography mass spectrometry.

    Science.gov (United States)

    Nurul Syazana, M S; Gan, S H; Halim, A S; Shah, Nurul Syazana Mohamad; Gan, Siew Hua; Sukari, Halim Ahmad

    2013-01-01

    The constituents of honey's volatile compounds depend on the nectar source and differ depending on the place of origin. To date, the volatile constituents of Tualang honey have never been investigated. The objective of this study was to analyze the volatile compounds in local Malaysian Tualang honey. A continuous extraction of Tualang honey using five organic solvents was carried out starting from non-polar to polar solvents and the extracted samples were analysed using gas chromatography-mass spectrometry (GC-MS). Overall, 35 volatile compounds were detected. Hydrocarbons constitute 58.5% of the composition of Tualang honey. Other classes of chemical compounds detected included acids, aldehydes, alcohols, ketones, terpenes, furans and a miscellaneous group. Methanol yielded the highest number of extracted compounds such as acids and 5-(Hydroxymethyl) furfural (HMF). This is the first study to describe the volatile compounds in Tualang honey. The use of a simple one tube, stepwise, non-thermal liquid-liquid extraction of honey is a advantageous as it prevents sample loss. Further research to test the clinical benefits of these volatile compounds is recommended.

  1. ANALYSIS OF THE RETURNS AND VOLATILITY OF THE ENVIRONMENTAL STOCK LEADERS

    Directory of Open Access Journals (Sweden)

    Viorica Chirila

    2013-09-01

    Full Text Available The last years have been faced with a blasting development of the Socially Responsible Investments (SRI worldwide even though the economic environment has been shaken by a global economic and financial crisis. The aim of this paper is to analyze the return and risk characteristics of the sustainably managed companies that pay particular attention to the environment responsibility in comparison with those that pay more attention to the corporate governance and respectively to the social responsibility. These characteristics are useful both to the individual and institutional investors as well as to the portfolio managers. For the comparative analysis we started from the study of descriptive characteristics of return and risk of indices portfolios of the environmental social and governance stock leaders and we focused on their univariate econometric modelling by means of the heteroskedastic models. The studies undertaken until now are centered on the performance obtained by the portfolios of sustainable indices and on the modelling of the volatility of sustainable indices. We would like to investigate the characteristics of return and risk of the assets of the sustainably managed companies that could attract active investors towards the sustainably managed companies that pay particular attention to the environment responsibility in comparison with those paying increased attention to the corporate governance and respectively to the social responsibility.

  2. Wet scrubber analysis of volatile organic compound removal in the rendering industry.

    Science.gov (United States)

    Kastner, James R; Das, K C

    2002-04-01

    The promulgation of odor control rules, increasing public concerns, and U.S. Environmental Protection Agency (EPA) air regulations in nonattainment zones necessitates the remediation of a wide range of volatile organic compounds (VOCs) generated by the rendering industry. Currently, wet scrubbers with oxidizing chemicals are used to treat VOCs; however, little information is available on scrubber efficiency for many of the VOCs generated within the rendering process. Portable gas chromatography/mass spectrometry (GC/MS) units were used to rapidly identify key VOCs on-site in process streams at two poultry byproduct rendering plants. On-site analysis was found to be important, given the significant reduction in peak areas if samples were held for 24 hr before analysis. Major compounds consistently identified in the emissions from the plant included dimethyl disulfide, methanethiol, octane, hexanal, 2-methylbutanal, and 3-methylbutanal. The two branched aldehydes, 2-methylbutanal and 3-methylbutanal, were by far the most consistent, appearing in every sample and typically the largest fraction of the VOC mixture. A chlorinated hydrocarbon, methanesulfonyl chloride, was identified in the outlet of a high-intensity wet scrubber, and several VOCs and chlorinated compounds were identified in the scrubbing solution, but not on a consistent basis. Total VOC concentrations in noncondensable gas streams ranged from 4 to 91 ppmv. At the two plants, the odor-causing compound methanethiol ranged from 25 to 33% and 9.6% of the total VOCs (v/v). In one plant, wet scrubber analysis using chlorine dioxide (ClO2) as the oxidizing agent indicated that close to 100% of the methanethiol was removed from the gas phase, but removal efficiencies ranged from 20 to 80% for the aldehydes and hydrocarbons and from 23 to 64% for total VOCs. In the second plant, conversion efficiencies were much lower in a packed-bed wet scrubber, with a measurable removal of only dimethyl sulfide (20-100%).

  3. Analysis of honeybush tea (Cyclopia spp.) volatiles by comprehensive two-dimensional gas chromatography using a single-stage thermal modulator.

    Science.gov (United States)

    Ntlhokwe, Gaalebalwe; Tredoux, Andreas G J; Górecki, Tadeusz; Edwards, Matthew; Vestner, Jochen; Muller, Magdalena; Erasmus, Lené; Joubert, Elizabeth; Christel Cronje, J; de Villiers, André

    2017-07-01

    The applicability of comprehensive two-dimensional gas chromatography (GC×GC) using a single-stage thermal modulator was explored for the analysis of honeybush tea (Cyclopia spp.) volatile compounds. Headspace solid phase micro-extraction (HS-SPME) was used in combination with GC×GC separation on a non-polar × polar column set with flame ionisation (FID) detection for the analysis of fermented Cyclopia maculata, Cyclopia subternata and Cyclopia genistoides tea infusions of a single harvest season. Method optimisation entailed evaluation of the effects of several experimental parameters on the performance of the modulator, the choice of columns in both dimensions, as well as the HS-SPME extraction fibre. Eighty-four volatile compounds were identified by co-injection of reference standards. Principal component analysis (PCA) showed clear differentiation between the species based on their volatile profiles. Due to the highly reproducible separations obtained using the single-stage thermal modulator, multivariate data analysis was simplified. The results demonstrate both the complexity of honeybush volatile profiles and the potential of GC×GC separation in combination with suitable data analysis techniques for the investigation of the relationship between sensory properties and volatile composition of these products. The developed method therefore offers a fast and inexpensive methodology for the profiling of honeybush tea volatiles. Graphical abstract Surface plot obtained for the GC×GC-FID analysis of honeybush tea volatiles.

  4. Unstable simple volatiles and gas chromatography-tandem mass spectrometry analysis of essential oil from the roots bark of Oplopanax horridus extracted by supercritical fluid extraction.

    Science.gov (United States)

    Shao, Li; Bao, Mei-Hua; Ouyang, Dong-Sheng; Wang, Chong-Zhi; Yuan, Chun-Su; Zhou, Hong-Hao; Huang, Wei-Hua

    2014-11-27

    Volatile oil from the root bark of Oplopanax horridus is regarded to be responsible for the clinical uses of the title plant as a respiratory stimulant and expectorant. Therefore, a supercritical fluid extraction method was first employed to extract the volatile oil from the roots bark of O. horridus, which was subsequently analyzed by GC/MS. Forty-eight volatile compounds were identified by GC/MS analysis, including (S,E)-nerolidol (52.5%), τ-cadinol (21.6%) and S-falcarinol (3.6%). Accordingly, the volatile oil (100 g) was subjected to chromatographic separation and purification. As a result, the three compounds, (E)-nerolidol (2 g), τ-cadinol (62 mg) and S-falcarinol (21 mg), were isolated and purified from the volatile oil, the structures of which were unambiguously elucidated by detailed spectroscopic analysis including 1D- and 2D-NMR techniques.

  5. Unstable Simple Volatiles and Gas Chromatography-Tandem Mass Spectrometry Analysis of Essential Oil from the Roots Bark of Oplopanax Horridus Extracted by Supercritical Fluid Extraction

    Directory of Open Access Journals (Sweden)

    Li Shao

    2014-11-01

    Full Text Available Volatile oil from the root bark of Oplopanax horridus is regarded to be responsible for the clinical uses of the title plant as a respiratory stimulant and expectorant. Therefore, a supercritical fluid extraction method was first employed to extract the volatile oil from the roots bark of O. horridus, which was subsequently analyzed by GC/MS. Forty-eight volatile compounds were identified by GC/MS analysis, including (S,E-nerolidol (52.5%, τ-cadinol (21.6% and S-falcarinol (3.6%. Accordingly, the volatile oil (100 g was subjected to chromatographic separation and purification. As a result, the three compounds, (E-nerolidol (2 g, τ-cadinol (62 mg and S-falcarinol (21 mg, were isolated and purified from the volatile oil, the structures of which were unambiguously elucidated by detailed spectroscopic analysis including 1D- and 2D-NMR techniques.

  6. Virtual volatility

    Science.gov (United States)

    Silva, A. Christian; Prange, Richard E.

    2007-03-01

    We introduce the concept of virtual volatility. This simple but new measure shows how to quantify the uncertainty in the forecast of the drift component of a random walk. The virtual volatility also is a useful tool in understanding the stochastic process for a given portfolio. In particular, and as an example, we were able to identify mean reversion effect in our portfolio. Finally, we briefly discuss the potential practical effect of the virtual volatility on an investor asset allocation strategy.

  7. Virtual volatility

    OpenAIRE

    A. Christian Silva; Prange, Richard E.

    2006-01-01

    We introduce the concept of virtual volatility. This simple but new measure shows how to quantify the uncertainty in the forecast of the drift component of a random walk. The virtual volatility also is a useful tool in understanding the stochastic process for a given portfolio. In particular, and as an example, we were able to identify mean reversion effect in our portfolio. Finally, we briefly discuss the potential practical effect of the virtual volatility on an investor asset allocation st...

  8. Plant volatiles.

    Science.gov (United States)

    Baldwin, Ian T

    2010-05-11

    Plant volatiles are the metabolites that plants release into the air. The quantities released are not trivial. Almost one-fifth of the atmospheric CO2 fixed by land plants is released back into the air each day as volatiles. Plants are champion synthetic chemists; they take advantage of their anabolic prowess to produce volatiles, which they use to protect themselves against biotic and abiotic stresses and to provide information - and potentially disinformation - to mutualists and competitors alike. As transferors of information, volatiles have provided plants with solutions to the challenges associated with being rooted in the ground and immobile.

  9. Analysis of volatile and oxidation sensitive compounds using a cold inlet system and electron impact mass spectrometry.

    Science.gov (United States)

    Sproß, Jens

    2014-09-05

    This video presents a protocol for the mass spectrometrical analysis of volatile and oxidation sensitive compounds using electron impact ionization. The analysis of volatile and oxidation sensitive compounds by mass spectrometry is not easily achieved, as all state-of-the-art mass spectrometric methods require at least one sample preparation step, e.g., dissolution and dilution of the analyte (electrospray ionization), co-crystallization of the analyte with a matrix compound (matrix-assisted laser desorption/ionization), or transfer of the prepared samples into the ionization source of the mass spectrometer, to be conducted under atmospheric conditions. Here, the use of a sample inlet system is described which enables the analysis of volatile metal organyls, silanes, and phosphanes using a sector field mass spectrometer equipped with an electron impact ionization source. All sample preparation steps and the sample introduction into the ion source of the mass spectrometer take place either under air-free conditions or under vacuum, enabling the analysis of compounds highly susceptible to oxidation. The presented technique is especially of interest for inorganic chemists, working with metal organyls, silanes, or phosphanes, which have to be handled using inert conditions, such as the Schlenk technique. The principle of operation is presented in this video.

  10. Latent Integrated Stochastic Volatility, Realized Volatility, and Implied Volatility: A State Space Approach

    DEFF Research Database (Denmark)

    Bach, Christian; Christensen, Bent Jesper

    We include simultaneously both realized volatility measures based on high-frequency asset returns and implied volatilities backed out of individual traded at the money option prices in a state space approach to the analysis of true underlying volatility. We model integrated volatility as a latent...... fi…rst order Markov process and show that our model is closely related to the CEV and Barndorff-Nielsen & Shephard (2001) models for local volatility. We show that if measurement noise in the observable volatility proxies is not accounted for, then the estimated autoregressive parameter in the latent...... process is downward biased. Implied volatility performs better than any of the alternative realized measures when forecasting future integrated volatility. The results are largely similar across the stock market (S&P 500), bond market (30-year U.S. T-bond), and foreign currency exchange market ($/£ )....

  11. Bioavailability assessment of toxic metals using the technique "acid-volatile sulfide (AVS)-simultaneously extracted metals (SEM)" in marine sediments collected in Todos os Santos Bay, Brazil.

    Science.gov (United States)

    Silva, Jucelino B; Nascimento, Rodrigo A; de Oliva, Sergio T; de Oliveira, Olívia M C; Ferreira, Sergio L C

    2015-10-01

    This paper reports the bioavailability of the metals (cadmium, copper, zinc, lead, and nickel) in sediment samples collected in seven stations from the São Paulo Estuary, Todos os Santos Bay, Brazil. The bioavailability was determined by employing the technique "acid-volatile sulfide (AVS) and simultaneously extracted metal (SEM)". The elements cadmium, copper, lead, and zinc were determined using differential pulse anodic stripping voltammetry (DPASV), while nickel was quantified utilizing electrothermal atomic absorption spectrometry (ET AAS). The accuracy of these methods was confirmed using a certified reference material of estuarine sediment (NIST 1646). The sulfide was quantified using potentiometry with selective electrode and the organic matter determination employing an indirect volumetric method using potassium dichromate and iron(II) sulfate solutions. The bioavailability of the metals was estimated by relationship between the concentration of AVS and the sum of the concentrations of the simultaneously extracted metals (ΣSEM), considering a significant toxicity when (ΣSEM)/(AVS) is higher than 1. The bioavailability values in the seven stations studied varied from 0.93 to 1.31 (June, 2014) and from 0.34 to 0.58 (September, 2014). These results demonstrated a critical condition of toxicity (bioavailability >1) in six of the seven sediment samples collected during the rainy season (June, 2014). In the other period (September, 2014), the bioavailability was always lower than 1 for all sediment samples collected in the seven stations. The individual values of the concentrations of the five metals were compared with the parameters PEL (probable effects level) and TEL (threshold effects level), which are commonly employed for characterization of ecological risk in environmental systems. This comparison revealed that all metals have concentrations lower than the PEL and only zinc and lead in some stations have contents higher than the TEL. The

  12. An overview of plant volatile metabolomics, sample treatment, and reporting considerations with emphasis on mechanical damage and biological control of weeds

    Science.gov (United States)

    Introduction – The technology for the collection and analysis of plant emitted volatiles for understanding chemical cues of plant-plant, plant-insect, or plant-microbe interactions has increased over the years. Consequently, the in situ collection, analysis, and identification of volatiles are consi...

  13. Gene expression analysis of volatile-rich male flowers of dioecious Pandanus fascicularis using expressed sequence tags.

    Science.gov (United States)

    Vinod, M S; Sankararamasubramanian, H M; Priyanka, R; Ganesan, G; Parida, Ajay

    2010-07-15

    Pandanus fascicularis is dioecious with the female plant producing a non-scented fruit while the male produces a flower rich in volatiles. The essential oil extracted from the flowers is economically exploited as a natural flavouring agent as well as for its therapeutic properties. Molecular dissection of this distinct flower for identifying the genes responsible for its aroma by way of expressed sequence tags (ESTs) has not been initiated in spite of its economic viability. A male flower-specific cDNA library was constructed and 977 ESTs were generated. CAP3 analysis performed on the dataset revealed 83 contigs (549 ESTs) and 428 singlets, thereby yielding a total of 511 unigenes. Functional annotation using the BLAST2GO software resulted in 1952 Gene ontology (GO) functional classification terms for 621 sequences. Unknown proteins were further analysed with InterProScan to determine their functional motifs. RNA gel blot analysis of 26 functionally distinct transcripts potentially involved in flowering and volatile generation, using vegetative and reproductive tissues of both the sexes, revealed differential expression profiles. In addition to an overview of genes expressed, candidate genes with expression that are modulated predominantly in the male inflorescence were also identified. This is the first report on generation of ESTs to determine the subset of genes that can be used as potential candidates for future attempts aimed towards its genetic and genome analysis including metabolic engineering of floral volatiles in this economically important plant.

  14. Analysis on Volatile Constituents in Leaves and Fruits of Ficus carica by GC-MS

    Institute of Scientific and Technical Information of China (English)

    LI Jun; TIAN Yu-zeng; SUN Bao-ya; YANG Dan; CHEN Ji-ping; MEN Qi-ming

    2012-01-01

    Objective To identify and analyze the volatile constituents in the leaves and fruits ofFicus carica.Methods Gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) were used.Results The major components detected in volatile oil of the leaves were psoralen (10.12%),β-damascenone (10.17%),benzyl alcohol (4.56%),behenic acid (4.79%),and bergapten (1.99%),etc.The major components detected in volatile oil of the fruits were furfural (10.55%),5-methyl-2-furaldehyde (10.1%),and benzeneacetaldehyde (6.59%),etc.Conclusion A total of 121 volatile constituents are identified in the leaves and 108 in the fruits ofF.carica,among which 103 constituents are identified for the first time in the leaves and 100 in the fruits.Eighteen volatile constituents are identified in both leaves and fruits.

  15. Transmission of prices and price volatility in Australian electricity spot markets: a multivariate GARCH analysis

    Energy Technology Data Exchange (ETDEWEB)

    Worthington, A.; Kay-Spratley, A.; Higgs, H. [Queensland University of Technology, Brisbane (Australia). School of Economics and Finance

    2005-03-01

    This paper examines the transmission of spot electricity prices and price volatility among the five regional electricity markets in the Australian National Electricity Market: namely, New South Wales, Queensland, South Australia, the Snowy Mountains Hydroelectric Scheme and Victoria. A multivariate generalised autoregressive conditional heteroskedasticity model is used to identify the source and magnitude of price and price volatility spillovers. The results indicate the presence of positive own mean spillovers in only a small number of markets and no mean spillovers between any of the markets. This appears to be directly related to the physical transfer limitations of the present system of regional interconnection. Nevertheless, the large number of significant own-volatility and cross-volatility spillovers in all five markets indicates the presence of strong autoregressive conditional heteroskedasticity and generalised autoregressive conditional heteroskedasticity effects. This indicates that shocks in some markets will affect price volatility in others. Finally, and contrary to evidence from studies in North American electricity markets, the results also indicate that Australian electricity spot prices are stationary. (author)

  16. Transmission of prices and price volatility in Australian electricity spot markets. A multivariate GARCH analysis

    Energy Technology Data Exchange (ETDEWEB)

    Worthington, Andrew; Kay-Spratley, Adam; Higgs, Helen [School of Economics and Finance, Queensland University of Technology, G.P.O. Box 2434, Brisbane, Qld 4001 (Australia)

    2005-03-15

    This paper examines the transmission of spot electricity prices and price volatility among the five regional electricity markets in the Australian National Electricity Market: namely, New South Wales, Queensland, South Australia, the Snowy Mountains Hydroelectric Scheme and Victoria. A multivariate generalised autoregressive conditional heteroskedasticity model is used to identify the source and magnitude of price and price volatility spillovers. The results indicate the presence of positive own mean spillovers in only a small number of markets and no mean spillovers between any of the markets. This appears to be directly related to the physical transfer limitations of the present system of regional interconnection. Nevertheless, the large number of significant own-volatility and cross-volatility spillovers in all five markets indicates the presence of strong autoregressive conditional heteroskedasticity and generalised autoregressive conditional heteroskedasticity effects. This indicates that shocks in some markets will affect price volatility in others. Finally, and contrary to evidence from studies in North American electricity markets, the results also indicate that Australian electricity spot prices are stationary.

  17. Differentiating coeliac disease from irritable bowel syndrome by urinary volatile organic compound analysis--a pilot study.

    Directory of Open Access Journals (Sweden)

    Ramesh P Arasaradnam

    Full Text Available Coeliac disease (CD, a T-cell-mediated gluten sensitive enteropathy, affects ∼ 1% of the UK population and can present with wide ranging clinical features, often being mistaken for Irritable Bowel Syndrome (IBS. Heightened clinical awareness and serological screening identifies those with potential coeliac disease; the diagnosis is confirmed with duodenal biopsies, and symptom improvement with a gluten-free diet. Limitations to diagnosis are false negative serology and reluctance to undergo biopsy. The gut microbiome is altered in several gastrointestinal disorders, causing altered gut fermentation patterns recognisable by volatile organic compounds (VOC analysis in urine, breath and faeces. We aimed to determine if CD alters the urinary VOC pattern, distinguishing it from IBS. 47 patients were recruited, 27 with established CD, on gluten free diets, and 20 with diarrhoea-predominant IBS (D-IBS. Collected urine was stored frozen in 10 ml aliquots. For assay, the specimens were heated to 40 ± 0.1°C and the headspace analysed by Field Asymmetric Ion Mobility Spectrometry (FAIMS. Machine learning algorithms were used for statistical evaluation. Samples were also analysed using Gas chromatography and mass spectroscopy (GC-MS. Sparse logistic regression showed that FAIMS distinguishes VOCs in CD vs D-IBS with ROC curve AUC of 0.91 (0.83-0.99, sensitivity and specificity of 85% respectively. GCMS showed a unique peak at 4'67 found only in CD, not D-IBS, which correlated with the compound 1,3,5,7 cyclooctatetraene. This study suggests that FAIMS offers a novel, non-invasive approach to identify those with possible CD, and distinguishes from D-IBS. It offers the potential for monitoring compliance with a gluten-free diet at home. The presence of cyclooctatetraene in CD specimens will need further validation.

  18. Unstable volatility

    DEFF Research Database (Denmark)

    Casas, Isabel; Gijbels, Irène

    2012-01-01

    The objective of this paper is to introduce the break-preserving local linear (BPLL) estimator for the estimation of unstable volatility functions for independent and asymptotically independent processes. Breaks in the structure of the conditional mean and/or the volatility functions are common i...

  19. Unstable volatility

    DEFF Research Database (Denmark)

    Casas, Isabel; Gijbels, Irène

    2012-01-01

    The objective of this paper is to introduce the break-preserving local linear (BPLL) estimator for the estimation of unstable volatility functions for independent and asymptotically independent processes. Breaks in the structure of the conditional mean and/or the volatility functions are common i...

  20. Idiosyncratic Volatility Puzzle

    DEFF Research Database (Denmark)

    Aslanidis, Nektarios; Christiansen, Charlotte; Lambertides, Neophytos;

    from a large pool of macroeconomic and Önancial variables. Cleaning for macro-Önance e§ects reverses the puzzling negative relation between returns and idiosyncratic volatility documented previously. Portfolio analysis shows that the e§ects from macro-Önance factors are economically strong......In this paper, we scrutinize the cross-sectional relation between idiosyncratic volatility and stock returns. As a novelty, the idiosyncratic volatility is obtained by conditioning upon macro-Önance factors as well as upon traditional asset pricing factors. The macro-Önance factors are constructed...

  1. Chemical Profile of the Volatile Oil from the Leaves of Erythroxylum deciduum A. St.-Hil. (Erythroxylaceae, Collected in Goiânia, Goiás

    Directory of Open Access Journals (Sweden)

    Giuliana Muniz Vila Verde

    2016-06-01

    Full Text Available The Erythroxylum (Erythroxylaceae genus has about 130 species, which can be found in forest environments and cerrado. Studies with Erythroxylum species led to the isolation of secondary metabolites such as flavonóides, alkaloids, tannins, terpenes and phenylpropanoids that exhibit anti-oxidant activity, anti-carcinogenic, anti-inflammatory activity among others to be operated with pharmaceutical purposes. In order to contribute to the chemical elucidation of Erythroxylum genus, this research aimed to evaluate the composition of the essential oil from the leaves of E. deciduum A. St.-Hil. The botanical material was collected in the peri-urban area of the city of Goiânia, Goiás, Brazil, it was identified and had a voucher specimen deposited in the Herbarium of the State University of Goiás. The essential oil extraction was performed by hydrodistillation adapted by Clevenger. The essential oil chemical composition was determined by gas chromatography-mass spectrometry (GC/ MS. The species studied showed as major components: himachalol (3.49%, sandaracopimarinal (4.87%, ethyl 8cedren-13-ol (5.65% and ternina (6.37% whose description on the literature, points to the antimicrobial and allelopathic activity. Thus, These volatile components may be viable in obtaining bioproducts or as prototypes in the synthesis of compounds of pharmacotherapeutic, food and agricultural interest.

  2. Neglected chaos in international stock markets: Bayesian analysis of the joint return-volatility dynamical system

    Science.gov (United States)

    Tsionas, Mike G.; Michaelides, Panayotis G.

    2017-09-01

    We use a novel Bayesian inference procedure for the Lyapunov exponent in the dynamical system of returns and their unobserved volatility. In the dynamical system, computation of largest Lyapunov exponent by traditional methods is impossible as the stochastic nature has to be taken explicitly into account due to unobserved volatility. We apply the new techniques to daily stock return data for a group of six countries, namely USA, UK, Switzerland, Netherlands, Germany and France, from 2003 to 2014, by means of Sequential Monte Carlo for Bayesian inference. The evidence points to the direction that there is indeed noisy chaos both before and after the recent financial crisis. However, when a much simpler model is examined where the interaction between returns and volatility is not taken into consideration jointly, the hypothesis of chaotic dynamics does not receive much support by the data (;neglected chaos;).

  3. Personal exposure to mixtures of volatile organic compounds: modeling and further analysis of the RIOPA data.

    Science.gov (United States)

    Batterman, Stuart; Su, Feng-Chiao; Li, Shi; Mukherjee, Bhramar; Jia, Chunrong

    2014-06-01

    affect VOC exposures, many personal, environmental, and socioeconomic determinants remain to be identified, and the significance and applicability of the determinants reported in the literature are uncertain. To help answer these unresolved questions and overcome limitations of previous analyses, this project used several novel and powerful statistical modeling and analysis techniques and two large data sets. The overall objectives of this project were (1) to identify and characterize exposure distributions (including extreme values), (2) evaluate mixtures (including dependencies), and (3) identify determinants of VOC exposure. METHODS VOC data were drawn from two large data sets: the Relationships of Indoor, Outdoor, and Personal Air (RIOPA) study (1999-2001) and the National Health and Nutrition Examination Survey (NHANES; 1999-2000). The RIOPA study used a convenience sample to collect outdoor, indoor, and personal exposure measurements in three cities (Elizabeth, NJ; Houston, TX; Los Angeles, CA). In each city, approximately 100 households with adults and children who did not smoke were sampled twice for 18 VOCs. In addition, information about 500 variables associated with exposure was collected. The NHANES used a nationally representative sample and included personal VOC measurements for 851 participants. NHANES sampled 10 VOCs in common with RIOPA. Both studies used similar sampling methods and study periods. Specific Aim 1. To estimate and model extreme value exposures, extreme value distribution models were fitted to the top 10% and 5% of VOC exposures. Health risks were estimated for individual VOCs and for three VOC mixtures. Simulated extreme value data sets, generated for each VOC and for fitted extreme value and lognormal distributions, were compared with measured concentrations (RIOPA observations) to evaluate each model's goodness of fit. Mixture distributions were fitted with the conventional finite mixture of normal distributions and the semi

  4. Characterizing the Smell of Marijuana by Odor Impact of Volatile Compounds: An Application of Simultaneous Chemical and Sensory Analysis.

    Directory of Open Access Journals (Sweden)

    Somchai Rice

    Full Text Available Recent U.S. legislation permitting recreational use of marijuana in certain states brings the use of marijuana odor as probable cause for search and seizure to the forefront of forensic science, once again. This study showed the use of solid-phase microextraction with multidimensional gas chromatography--mass spectrometry and simultaneous human olfaction to characterize the total aroma of marijuana. The application of odor activity analysis offers an explanation as to why high volatile chemical concentration does not equate to most potent odor impact of a certain compound. This suggests that more attention should be focused on highly odorous compounds typically present in low concentrations, such as nonanal, decanol, o-cymene, benzaldehyde, which have more potent odor impact than previously reported marijuana headspace volatiles.

  5. GC-MS Analysis on Volatile Oil from Branches of Picrasma quassioides

    Institute of Scientific and Technical Information of China (English)

    HUANG Lin-fang; WANG Zeng-hui; CHEN Shi-lin

    2013-01-01

    Objective To analyze the volatile oil from the branches of Picrasma quassioides.Methods Volatile oil was extracted from the branches of P quassioides by steam distillation.GC-MS method was used to analyze the components.Results A total of 49 compounds were isolated,and 46 compounds were successfully identified,which represented over 98% of the total oil composition.The major components of the volatile oil in the branches of P.quassioides included caryophyllene (12.83%),12-oxabicyclo[9.1.0]dodeca-3,7-diene,1,5,5,8-tetramethyl-[1R-(1R*,3E,7E,11-R*)] (12.29%),1-hexanol (9.96%),naphthalene,1,2,3,5,6,7,8,8a-octahydro-1,8a-dimethyl-7-(1-methyletheyl)-[1S-(1a,7a,8aa)] (7.32%),aromadendrene oxide-(2) (6.69%),and α-caryophyllene (3.88%).Conclusion The major components in volatile oil are terpenoids,hydroxy compounds,and other acyclic alkane compounds.

  6. GC-MS Analysis on Volatile Oil from Branches of Picrasma quassioides

    Institute of Scientific and Technical Information of China (English)

    HUANG; Lin-fang; WANG; Zeng-hui; CHEN; Shi-lin

    2013-01-01

    Objective To analyze the volatile oil from the branches of Picrasma quassioides. Methods Volatile oil was extracted from the branches of P. quassioides by steam distillation. GC-MS method was used to analyze the components. Results A total of 49 compounds were isolated, and 46 compounds were successfully identified, which represented over 98% of the total oil composition. The major components of the volatile oil in the branches of P. quassioides included caryophyllene (12.83%), 12-oxabicyclo[9.1.0]dodeca-3,7-diene,1,5,5,8-tetramethyl-[1R-(1R*,3E,7E,11-R*)] (12.29%), 1-hexanol (9.96%), naphthalene, 1,2,3,5,6,7,8,8a-octahydro-1,8a-dimethyl-7-(1-methyletheyl)-[1S-(1a,7a,8aa)] (7.32%), aromadendrene oxide-(2) (6.69%), and α-caryophyllene (3.88%). Conclusion The major components in volatile oil are terpenoids, hydroxy compounds, and other acyclic alkane compounds.

  7. Symmetry analysis of Black-Scholes equation for small values of volatility and rate of return

    Directory of Open Access Journals (Sweden)

    M. Nadjafikhah

    2014-07-01

    of volatility and rate of return parameters. A novel method for obtaining the approximate symmetry of a singularly perturbed partial differential equation (PDE is introduced. Further, we compute the optimal system in the singular case. Finally, by combining two methods, a new approach that calculates the approximate generators for admitted Lie groups of asset price is provided.

  8. Analysis of organic volatile flavor compounds in fermented stinky tofu using SPME with different fiber coatings.

    Science.gov (United States)

    Liu, Yuping; Miao, Zhiwei; Guan, Wei; Sun, Baoguo

    2012-03-26

    The organic volatile flavor compounds in fermented stinky tofu (FST) were studied using SPME-GC/MS. A total of 39 volatile compounds were identified, including nine esters, seven alcohols, five alkenes, four sulfides, three heterocycles, three carboxylic acids, three ketones, two aldehydes, one phenol, one amine and one ether. These compounds were determined by MS, and conformed by comparison of the retention times of the separated constituents with those of authentic samples and by comparison of retention indexes (RIs) of separated constituents with the RIs reported in the literature. The predominant volatile compound in FST was indole, followed by dimethyl trisulfide, phenol, dimethyl disulfide and dimethyl tetrasulfide. In order to find a better extraction time, the extraction times was optimized for each type of SPME fiber; the results show that the best extraction time for Carboxen/PDMS is 60 min, for PDMS/DVB 30 min, for DVB/CAR/PDMS 60 min and for PDMS 75 min. Of the four fibers used in this work, Carboxen/PDMS is found to be the most suitable to extract the organic volatile flavor compounds in fermented stinky tofu.

  9. Analysis of Organic Volatile Flavor Compounds in Fermented Stinky Tofu Using SPME with Different Fiber Coatings

    Directory of Open Access Journals (Sweden)

    Wei Guan

    2012-03-01

    Full Text Available The organic volatile flavor compounds in fermented stinky tofu (FST were studied using SPME-GC/MS. A total of 39 volatile compounds were identified, including nine esters, seven alcohols, five alkenes, four sulfides, three heterocycles, three carboxylic acids, three ketones, two aldehydes, one phenol, one amine and one ether. These compounds were determined by MS, and conformed by comparison of the retention times of the separated constituents with those of authentic samples and by comparison of retention indexes (RIs of separated constituents with the RIs reported in the literature. The predominant volatile compound in FST was indole, followed by dimethyl trisulfide, phenol, dimethyl disulfide and dimethyl tetrasulfide. In order to find a better extraction time, the extraction times was optimized for each type of SPME fiber; the results show that the best extraction time for Carboxen/PDMS is 60 min, for PDMS/DVB 30 min, for DVB/CAR/PDMS 60 min and for PDMS 75 min. Of the four fibers used in this work, Carboxen/PDMS is found to be the most suitable to extract the organic volatile flavor compounds in fermented stinky tofu.

  10. On stochastic integration for volatility modulated Brownian-driven Volterra processes via white noise analysis

    DEFF Research Database (Denmark)

    E. Barndorff-Nielsen, Ole; Benth, Fred Espen; Szozda, Benedykt

    This paper generalizes the integration theory for volatility modulated Brownian-driven Volterra processes onto the space G* of Potthoff-Timpel distributions. Sufficient conditions for integrability of generalized processes are given, regularity results and properties of the integral are discussed...

  11. On stochastic integration for volatility modulated Brownian-driven Volterra processes via white noise analysis

    DEFF Research Database (Denmark)

    Barndorff-Nielsen, Ole E.; Benth, Fred Espen; Szozda, Benedykt

    This paper generalizes the integration theory for volatility modulated Brownian-driven Volterra processes onto the space G∗ of Potthoff--Timpel distributions. Sufficient conditions for integrability of generalized processes are given, regularity results and properties of the integral are discussed...

  12. Analysis of volatile organic compound from Elaeis guineensis inflorescences planted on different soil types in Malaysia

    Science.gov (United States)

    Muhamad Fahmi, M. H.; Ahmad Bukhary, A. K.; Norma, H.; Idris, A. B.

    2016-11-01

    The main attractant compound for Eleidobius kamerunicus to male spikelet Elaeis guineensis (oil palm) were determined by analyzing volatile organic compound extracted from E. guineenses inflorescences planted on different soil types namely peat soil, clay soil and sandy soil. Anthesizing male oil palm inflorescences were randomly choosen from palm aged between 4-5 years old age. Extraction of the volatiles from the oil palm inflorescences were performed by Accelerated Solvent Extraction method (ASE). The extracted volatile compound were determined by using gas chromatography-mass spectrometry. Out of ten identified compound, estragole was found to be a major compound in sandy soil (37.49%), clay soil (30.71%) and peat soil (27.79%). Other compound such as 9,12-octadecadieonic acid and n-hexadecanoic acid were found as major compound in peat soil (27.18%) and (7.45%); sandy soil (14.15 %) and (9.31%); and clay soil (30.23%) and (4.99%). This study shows that estragole was the predominant volatile compound detected in oil palm inflorescences with highly concentrated in palm planted in sandy soil type.

  13. An overview of plant volatile metabolomics, sample treatment and reporting considerations with emphasis on mechanical damage and biological control of weeds.

    Science.gov (United States)

    Beck, John J; Smith, Lincoln; Baig, Nausheena

    2014-01-01

    The technology for the collection and analysis of plant-emitted volatiles for understanding chemical cues of plant-plant, plant-insect or plant-microbe interactions has increased over the years. Consequently, the in situ collection, analysis and identification of volatiles are considered integral to elucidation of complex plant communications. Due to the complexity and range of emissions the conditions for consistent emission of volatiles are difficult to standardise. To discuss: evaluation of emitted volatile metabolites as a means of screening potential target- and non-target weeds/plants for insect biological control agents; plant volatile metabolomics to analyse resultant data; importance of considering volatiles from damaged plants; and use of a database for reporting experimental conditions and results. Recent literature relating to plant volatiles and plant volatile metabolomics are summarised to provide a basic understanding of how metabolomics can be applied to the study of plant volatiles. An overview of plant secondary metabolites, plant volatile metabolomics, analysis of plant volatile metabolomics data and the subsequent input into a database, the roles of plant volatiles, volatile emission as a function of treatment, and the application of plant volatile metabolomics to biological control of invasive weeds. It is recommended that in addition to a non-damaged treatment, plants be damaged prior to collecting volatiles to provide the greatest diversity of odours. For the model system provided, optimal volatile emission occurred when the leaf was punctured with a needle. Results stored in a database should include basic environmental conditions or treatments. Copyright © 2013 John Wiley & Sons, Ltd.

  14. The effects of exchange rate volatility on international trade fl ows: evidence from panel data analysis and fuzzy approach

    Directory of Open Access Journals (Sweden)

    Robert M. Kunst

    2012-06-01

    Full Text Available The aim of this paper is to analyze the effects of exchange rate volatility on international trade flows by using two different approaches, the panel data analysis and fuzzy logic, and to compare the results. To a panel with the crosssection dimension of 91 pairs of EU15 countries and with time ranging from 1964 to 2003, an extended gravity model of trade is applied in order to determine theeffects of exchange rate volatility on bilateral trade flows of EU15 countries. The estimated impact is clearly negative, which indicates that exchange rate volatility has a negative influence on bilateral trade flows. Then, this traditional panel approach is contrasted with an alternative investigation based on fuzzy logic. The key elements of the fuzzy approach are to set fuzzy decision rules and to assignmembership functions to the fuzzy sets intuitively based on experience. Both approaches yield very similar results and fuzzy approach is recommended to be used as a complement to statistical methods.

  15. Volatile profile analysis and quality prediction of Longjing tea (Camellia sinensis) by HS-SPME/GC-MS

    Institute of Scientific and Technical Information of China (English)

    Jie LIN; Yi DAI; Ya-nan GUO; Hai-rong XU; Xiao-chang WANG

    2012-01-01

    This study aimed to analyze the volatile chemical profile of Longjing tea,and further develop a prediction model for aroma quality of Longjing tea based on potent odorants.A total of 21 Longjing samples were analyzed by headspace solid phase microextraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS).Pearson's linear correlation analysis and partial least square (PLS) regression were applied to investigate the relationship between sensory aroma scores and the volatile compounds.Results showed that 60 volatile compounds could be commonly detected in this famous green tea.Terpenes and esters were two major groups characterized,representing 33.89% and 15.53% of the total peak area respectively.Ten compounds were determined to contribute significantly to the perceived aroma quality of Longjing tea,especially linalool (0.701),nonanal (0.738),(Z)-3-hexenyl hexanoate (-0.785),and β-ionone (-0.763).On the basis of these 10 compounds,a model (correlation coefficient of 89.4% and cross-validated correlation coefficient of 80.4%) was constructed to predict the aroma quality of Longjing tea.Summarily,this study has provided a novel option for quality prediction of green tea based on HS-SPME/GC-MS technique.

  16. Unstable Simple Volatiles and Gas Chromatography-Tandem Mass Spectrometry Analysis of Essential Oil from the Roots Bark of Oplopanax Horridus Extracted by Supercritical Fluid Extraction

    OpenAIRE

    Li Shao; Mei-Hua Bao; Dong-Sheng Ouyang; Chong-Zhi Wang; Chun-Su Yuan; Hong-Hao Zhou; Wei-Hua Huang

    2014-01-01

    Volatile oil from the root bark of Oplopanax horridus is regarded to be responsible for the clinical uses of the title plant as a respiratory stimulant and expectorant. Therefore, a supercritical fluid extraction method was first employed to extract the volatile oil from the roots bark of O. horridus, which was subsequently analyzed by GC/MS. Forty-eight volatile compounds were identified by GC/MS analysis, including (S,E)-nerolidol (52.5%), τ-cadinol (21.6%) and S-falcarinol (3.6%). Accordi...

  17. A system and methodology for measuring volatile organic compounds produced by hydroponic lettuce in a controlled environment

    Science.gov (United States)

    Charron, C. S.; Cantliffe, D. J.; Wheeler, R. M.; Manukian, A.; Heath, R. R.

    1996-01-01

    A system and methodology were developed for the nondestructive qualitative and quantitative analysis of volatile emissions from hydroponically grown 'Waldmann's Green' leaf lettuce (Lactuca sativa L.). Photosynthetic photon flux (PPF), photoperiod, and temperature were automatically controlled and monitored in a growth chamber modified for the collection of plant volatiles. The lipoxygenase pathway products (Z)-3-hexenal, (Z)-3-hexenol, and (Z)-3-hexenyl acetate were emitted by lettuce plants after the transition from the light period to the dark period. The volatile collection system developed in this study enabled measurements of volatiles emitted by intact plants, from planting to harvest, under controlled environmental conditions.

  18. PIXE analysis of atmospheric aerosols collected over Hungary and Japan

    Science.gov (United States)

    Katoh, T.; Amemiya, S.; Tsurita, Y.; Masuda, T.; Koltay, E.; Borbély-Kiss, I.

    1993-04-01

    The PIXE analysis of atmospheric samples collected over Hungary and Japan has been made to investigate characteristic features of the samples of Hungary and Japan, and to compare them. Samples were collected at Budapest, Debrecen, Szerencs, Pálháza in Hungary, and at Tokyo, Noma coast Aichi, Obara-mura Aichi (rural district), Mt. Rokko, in Japan. The PIXE analysis of the samples was made using a 2 MeV proton beam from a Van de Graaff accelerator at Nagoya University. Differences, specially in the concentration of lead, between samples collected in Hungary and Japan were observed.

  19. Chasing volatility

    DEFF Research Database (Denmark)

    Caporin, Massimiliano; Rossi, Eduardo; Santucci de Magistris, Paolo

    The realized volatility of financial returns is characterized by persistence and occurrence of unpreditable large increments. To capture those features, we introduce the Multiplicative Error Model with jumps (MEM-J). When a jump component is included in the multiplicative specification, the condi...... models, the introduction of the jump component provides a sensible improvement in the fit, as well as for in-sample and out-of-sample volatility tail forecasts....

  20. Volatility Risk

    OpenAIRE

    Zhiguang Wang

    2009-01-01

    Classical capital asset pricing theory tells us that riskaverse investors would require higher returns to compensate for higher risk on an investment. One type of risk is price (return) risk, which reflects uncertainty in the price level and is measured by the volatility (standard deviation) of asset returns. Volatility itself is also known to be random and hence is perceived as another type of risk. Investors can bear price risk in exchange for a higher return. But are investors willing to p...

  1. Fast analysis of volatile organic compounds and disinfection by-products in drinking water using solid-phase microextraction-gas chromatography/time-of-flight mass spectrometry.

    Science.gov (United States)

    Niri, Vadoud H; Bragg, Leslie; Pawliszyn, Janusz

    2008-08-08

    A fast method was developed for the extraction and analysis of volatile organic compounds, including disinfection by-products (DBPs), with headspace solid-phase microextraction (HS-SPME) and gas chromatography/mass spectrometry (GC/MS) techniques. A GC/time-of-flight (TOF)-MS instrument, which had fast acquisition rates and powerful deconvolution software, was used. Under optimum conditions total runtime was 45s. Volatile organic compounds (VOCs), including purgeable A and B compounds (listed in US Environmental Protection Agency method 624), were identified in standard water samples. Extraction times were 1min for more volatile compounds and 2min for less volatile compounds. The method was applied to the analysis of water samples treated under different disinfection processes and the results were compared with those from a liquid-liquid extraction method.

  2. Evaluation of volatile metabolites as markers in Lycopersicon esculentum L. cultivars discrimination by multivariate analysis of headspace solid phase microextraction and mass spectrometry data.

    Science.gov (United States)

    Figueira, José; Câmara, Hugo; Pereira, Jorge; Câmara, José S

    2014-02-15

    To gain insights on the effects of cultivar on the volatile metabolomic expression of different tomato (Lycopersicon esculentum L.) cultivars--Plum, Campari, Grape, Cherry and Regional, cultivated under similar edafoclimatic conditions, and to identify the most discriminate volatile marker metabolites related to the cultivar, the chromatographic profiles resulting from headspace solid phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-qMS) analysis, combined with multivariate analysis were investigated. The data set composed by the 77 volatile metabolites identified in the target tomato cultivars, 5 of which (2,2,6-trimethylcyclohexanone, 2-methyl-6-methyleneoctan-2-ol, 4-octadecyl-morpholine, (Z)-methyl-3-hexenoate and 3-octanone) are reported for the first time in tomato volatile metabolomic composition, was evaluated by chemometrics. Firstly, principal component analysis was carried out in order to visualise data trends and clusters, and then, linear discriminant analysis in order to detect the set of volatile metabolites able to differentiate groups according to tomato cultivars. The results obtained revealed a perfect discrimination between the different Lycopersicon esculentum L. cultivars considered. The assignment success rate was 100% in classification and 80% in prediction ability by using "leave-one-out" cross-validation procedure. The volatile profile was able to differentiate all five cultivars and revealed complex interactions between them including the participation in the same biosynthetic pathway. The volatile metabolomic platform for tomato samples obtained by HS-SPME/GC-qMS here described, and the interrelationship detected among the volatile metabolites can be used as a roadmap for biotechnological applications, namely to improve tomato aroma and their acceptance in the final consumer, and for traceability studies. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. Does political instability lead to higher and more volatile inflation?: A panel data analysis

    Directory of Open Access Journals (Sweden)

    Aisen Ari

    2007-01-01

    Full Text Available Economists generally accept the proposition that high and volatile inflation rates generate inefficiencies that reduce society’s welfare. Furthermore studies have shown that inflation is harmful to economic growth. However determining the causes of the worldwide diversity of inflationary experiences is an important challenge not yet satisfactorily confronted by the profession. Based on a broad dataset covering over 100 countries for the period 1975-1997 and using dynamic and static panel data econometric techniques, this paper shows that a higher degree of political instability is associated with both higher inflation levels and volatility. Not only does this paper advance the political economy literature establishing a relationship between inflation moments and political instability, but it also has important policy implications regarding the optimal design of inflation stabilization programs and of the institutions favorable to price stability.

  4. [Emission characteristics and hazard assessment analysis of volatile organic compounds from chemical synthesis pharmaceutical industry].

    Science.gov (United States)

    Li, Yan; Wang, Zhe-Ming; Song, Shuang; Xu, Zhi-Rong; Xu, Ming-Zhu; Xu, Wei-Li

    2014-10-01

    In this study, volatile organic compounds (VOCs) released from chemical synthesis pharmaceutical industry in Taizhou, Zhejiang province were analyzed quantitatively and qualitatively. The total volatile organic compounds (TVOCs) was in the range of 14.9-308.6 mg · m(-3). Evaluation models of ozone formation potentials (OFP) and health risk assessment were adopted to preliminarily assess the environmental impact and health risk of VOCs. The results showed that the values of OFP of VOCs were in the range of 3.1-315.1 mg · m(-3), based on the maximum incremental reactivity, the main principal contribution was toluene, tetrahydrofuran (THF), acetic ether etc. The non-carcinogenic risk and the carcinogen risk fell in the ranges of 9.48 x 10(-7)-4.98 x 10(-4) a(-1) and 3.17 x 10(-5)- 6.33 x 10(-3). The principal contribution of VOCs was benzene, formaldehyde and methylene chloride.

  5. Analysis of Volatile Components in Strawberry Cultivars Xingdu 1 and Xingdu 2 and Their Parents

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yun-tao; WANG Gui-xia; DONG Jing; ZHONG Chuan-fei; KONG Jin; LI Tian-zhong; HAN Zhen-hai

    2009-01-01

    To study differences and genetic trends of volatiles in Xingdu 1 and Xingdu 2,the strawberry cultivars,with their parents,the volatile components were analyzed by head space-solid phase microextraetion and gas chromatography-mass spectrometry.The results indicated that a total of 50 compounds were identified in Xingdu 1 cultivar,including hexanoic acid methyl ester and hexanoie acid ethyl ester,butanoic acid methyl ester,and butanoic acid ethyl ester,octanoic acid methyl ester and octanoic acid ethyl ester,isomyl hexanoate.And there were 71 compounds in Xingdu 2,which were similar to that of Xingdu 1.About 55 volatiles were identified in Allstar(female parent),including acetone,acetic acid 1-methylethyl ester,1-octanol,hexanoic acid ethyl ester and butanoic acid methyl ester.And 43 volatiles were identified in Toyonoka(male parent),including hexanoie acid ethyl ester,nerolidol,1-octanol,hexanoic acid methyl ester,acetic acid octyl ester,isomyl hexanoate and octanoic acid methyl ester.Consequently,hexanoic acid methyl ester and hexanoic acid ethyl ester,butanoic acid methyl ester,and butanoic acid ethyl ester and isomyl hexanoate in twins might be affected both sides of their parents.In the family,male parent(Toyonoka)had the highest concentrations of fragrance alcohols,such as nerolidol,linalool and 1-octanol,but which couldn't be transmitted to the descendants.Acetone,acetic acid 1-methylethyl ester of the twins originally came from matrilinear inheritance,as the contents of the two compounds were very high in Allstar but little in Toyonoka.Genetic trends of butanoic acid methyl ester,butanoic acid ethyl ester,hexanoic acid ethyl ester,hexanoic acid methyl ester and isomyl hexanoate were affected by both sides of parents.

  6. Analysis of chemical constituents of the volatile oil from leaves of Solanum bicolor.

    Science.gov (United States)

    Colmenares, Alida Pérez; Rojas, Luis B; Arias, Eilen; Arzola, Juan Carmona; Usubillaga, Alfredo

    2010-04-01

    The volatile components from the leaves of Solanum bicolor Roemer & Schultes, was obtained by hydrodistillation and was analizad by GC/MS. A total of 20 compounds, representing 96.3 % of the oil, were identified. The dominant compounds were trans-caryophyllene (23.2%), trans-2-pentadecene (22.6%), germacrene D (12.2%), biciclogermecrene (8.0%) and caryophyllene oxide (4.7%).

  7. An improved method for the analysis of volatile polyfluorinated alkyl substances in environmental air samples

    Energy Technology Data Exchange (ETDEWEB)

    Jahnke, Annika; Ahrens, Lutz [Institute for Coastal Research, GKSS Research Centre, Department of Environmental Chemistry, Geesthacht (Germany); University of Lueneburg, Institute for Ecology and Environmental Chemistry, Faculty of Environmental Sciences, Lueneburg (Germany); Ebinghaus, Ralf; Temme, Christian [Institute for Coastal Research, GKSS Research Centre, Department of Environmental Chemistry, Geesthacht (Germany); Berger, Urs [Norwegian Institute for Air Research (NILU), Polar Environmental Centre, Tromsoe (Norway); Stockholm University, Department of Applied Environmental Science (ITM), Stockholm (Sweden); Barber, Jonathan L. [Lancaster University, Department of Environmental Science, Faculty of Science and Technology, Lancaster (United Kingdom)

    2007-02-15

    This article describes the optimisation and validation of an analytical method for the determination of volatile polyfluorinated alkyl substances (PFAS) in environmental air samples. Airborne fluorinated telomer alcohols (FTOHs) as well as fluorinated sulfonamides and sulfonamidoethanols (FOSAs/FOSEs) were enriched on glass-fibre filters (GFFs), polyurethane foams (PUFs) and XAD-2 resin by means of high-volume air samplers. Sensitive and selective determination was performed using gas chromatography/chemical ionisation-mass spectrometry (GC/CI-MS). Five mass-labelled internal standard (IS) compounds were applied to ensure the accuracy of the analytical results. No major blank problems were encountered. Recovery experiments were performed, showing losses of the most volatile compounds during extraction and extract concentration as well as strong signal enhancement for FOSEs due to matrix effects. Breakthrough experiments revealed losses of the most volatile FTOHs during sampling, while FOSAs/FOSEs were quantitatively retained. Both analyte losses and matrix effects could be remediated by application of adequate mass-labelled IS. Method quantification limits (MQLs) of the optimised method ranged from 0.2 to 2.5 pg/m{sup 3} for individual target compounds. As part of the method validation, an interlaboratory comparison of instrumental quantification methods was conducted. The applicability of the method was demonstrated by means of environmental air samples from an urban and a rural location in Northern Germany. (orig.)

  8. Headspace Solid-Phase Microextraction Analysis of Volatile Components in Narcissus tazetta var. chinensis Roem

    Directory of Open Access Journals (Sweden)

    Hai-Shan Chi

    2013-11-01

    Full Text Available The volatile components in single-flowered and double-flowered Chinese narcissus were identified by headspace-solid phase microextraction (HS-SPME coupled with GC and GC/MS. Changes in aroma during the vase-life (days 0, 1, 2, 3, 4, 5 and 6 of two samples were also studied. A total of 35 compounds were identified, of which all were present in single-flowered and 26 in double-flowered samples. The main aroma components were (E-β-ocimene, and benzyl acetate. Single-flowered narcissus have a higher percentage of benzyl acetate, while double-flowered narcissus have a higher percentage of 1,8-cineole. In vase-life, the total volatile component content peaked on day 2 for single-flowered and day 3 for the double-flowered narcissus. For both single-flowered and double-flowered narcissus flowers, the total content of volatile components had decreased significantly by day 4.

  9. ANALYSIS AND FORECASTING THE VOLATILITY OF EURO – DOLLAR EXCHANGE RATE

    Directory of Open Access Journals (Sweden)

    Václava Pánková

    2010-12-01

    Full Text Available The study on volatility and asymmetry of the exchange rate is applied to the Euro/USD relation. Starting in U.S.A., the financial and economic crisis influenced European Union with a certain delay. On the other hand, this years´ problems in Eurozone are paralleled by rising American economy. That is why we can expect both currencies to develop in different ways. In general, the depreciation deviation of exchange rate can lead to a higher volatility than the appreciation deviation, what implicates asymmetric effects. The uncertainty of exchange rate has a tendency to be inconstant in the time-varying cases, so it has a feature of conditional heteroscedasticity. That is why the models from the ARCH family are employed to study whether the asymmetry is present in the data in question; source: ECB. The Engle – Ng tests for asymmetry in volatility are used to determine whether an asymmetric model is required as adequate. A forecast will be given including an ex post comparison as well as an ex ante prognosis. Financial support from the GA CR project 402/09/0273 and the Research Plan MSM 6138439909 is appreciated.

  10. Comparison of four extraction methods for analysis of volatile hop-derived aroma compounds in beer.

    Science.gov (United States)

    Richter, Tobias M; Eyres, Graham T; Silcock, Patrick; Bremer, Phil J

    2017-09-09

    The volatile organic compound profile in beer is derived from hops, malt, yeast, and interactions between the ingredients, making it very diverse and complex. Due to the range and diversity of the volatile organic compounds present, the choice of the extraction method is extremely important for optimal sensitivity and selectivity. This study compared four extraction methods for hop-derived compounds in beer late hopped with Nelson Sauvin. Extraction capacity and variation were compared for headspace solid phase micro extraction, stir bar sorptive extraction, headspace sorptive extraction, and solvent assisted flavour evaporation. Generally, stir bar sorptive extraction was better suited for acids, headspace sorptive extraction for esters and aldehydes, while headspace solid phase micro extraction was less sensitive overall, extracting 40% fewer compounds. Solvent assisted flavour evaporation with dichloromethane was not suitable for the extraction of hop-derived volatile organic compounds in beer, as the profile was strongly skewed towards alcohols and acids. Overall, headspace sorptive extraction found to be best suited, closely followed by stir bar sorptive extraction. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  11. Analysis of the volatile aroma constituents of parental and hybrid clones of pepino (Solanum muricatum).

    Science.gov (United States)

    Rodríguez-Burruezo, Adrián; Kollmannsberger, Hubert; Prohens, Jaime; Nitz, Siegfried; Nuez, Fernando

    2004-09-08

    The volatile constituents of 10 clones (4 parents with different flavors and 6 hybrids from selected crossings among these parents) of pepino fruit (Solanum muricatum) were isolated by simultaneous distillation-extraction and analyzed by gas chromatography-mass spectrometry (GC-MS). Odor-contributing volatiles (OCVs) were detected by GC-olfactometry-MS analyses and included 24 esters (acetates, 3-methylbutanoates, and 3-methylbut-2-enoates), 7 aldehydes (especially hexenals and nonenals), 6 ketones, 9 alcohols, 3 lactones, 2 terpenes, beta-damascenone, and mesifurane. Among these compounds, 17, of which 5 had not been reported previously in pepino, were found to contribute significantly to pepino aroma. OCVs can be assigned to three groups according to their odor quality: fruity fresh (acetates and prenol), green vegetable (C6 and C9 aldehydes), and exotic (lactones, mesifuran, and beta-damascenone). Quantitative and qualitative differences between clones for these compounds are clearly related to differences in their overall flavor impression. The positive value found for the hybrid-midparent regression coefficient for volatile composition indicates that an important fraction of the variation observed is inheritable, which has important implications in breeding for improving aroma. Significant and positive correlations were found between OCVs having common precursors or related pathways.

  12. Lie Symmetry Analysis of the Black-Scholes-Merton Model for European Options with Stochastic Volatility

    Directory of Open Access Journals (Sweden)

    Andronikos Paliathanasis

    2016-05-01

    Full Text Available We perform a classification of the Lie point symmetries for the Black-Scholes-Merton Model for European options with stochastic volatility, σ, in which the last is defined by a stochastic differential equation with an Orstein-Uhlenbeck term. In this model, the value of the option is given by a linear (1 + 2 evolution partial differential equation in which the price of the option depends upon two independent variables, the value of the underlying asset, S, and a new variable, y. We find that for arbitrary functional form of the volatility, σ ( y , the (1 + 2 evolution equation always admits two Lie point symmetries in addition to the automatic linear symmetry and the infinite number of solution symmetries. However, when σ ( y = σ 0 and as the price of the option depends upon the second Brownian motion in which the volatility is defined, the (1 + 2 evolution is not reduced to the Black-Scholes-Merton Equation, the model admits five Lie point symmetries in addition to the linear symmetry and the infinite number of solution symmetries. We apply the zeroth-order invariants of the Lie symmetries and we reduce the (1 + 2 evolution equation to a linear second-order ordinary differential equation. Finally, we study two models of special interest, the Heston model and the Stein-Stein model.

  13. Analysis of volatile organic compounds in pleural effusions by headspace solid-phase microextraction coupled with cryotrap gas chromatography and mass spectrometry.

    Science.gov (United States)

    Huang, Zhongping; Zhang, Jie; Zhang, Peipei; Wang, Hong; Pan, Zaifa; Wang, Lili

    2016-07-01

    Headspace solid-phase microextraction coupled with cryotrap gas chromatography and mass spectrometry was applied to the analysis of volatile organic compounds in pleural effusions. The highly volatile organic compounds were separated successfully with high sensitivity by the employment of a cryotrap device, with the construction of a cold column head by freezing a segment of metal capillary with liquid nitrogen. A total of 76 volatile organic compounds were identified in 50 pleural effusion samples (20 malignant effusions and 30 benign effusions). Among them, 34 more volatile organic compounds were detected with the retention time less than 8 min, by comparing with the normal headspace solid-phase microextraction coupled with gas chromatography and mass spectrometry method. Furthermore, 24 volatile organic compounds with high occurrence frequency in pleural effusion samples, 18 of which with the retention time less than 8 min, were selected for the comparative analysis. The results of average peak area comparison and box-plot analysis showed that except for cyclohexanone, 2-ethyl-1-hexanol, and tetramethylbenzene, which have been reported as potential cancer biomarkers, cyclohexanol, dichloromethane, ethyl acetate, n-heptane, ethylbenzene, and xylene also had differential expression between malignant and benign effusions. Therefore, the proposed approach was valuable for the comprehensive characterization of volatile organic compounds in pleural effusions.

  14. GC/MS analysis of volatiles obtained by headspace solid-phase microextraction and simultaneous-distillation extraction from Rabdosia serra (MAXIM.) HARA leaf and stem.

    Science.gov (United States)

    Lin, Lianzhu; Zhuang, Mingzhu; Lei, Fenfen; Yang, Bao; Zhao, Mouming

    2013-01-15

    Volatiles in Rabdosia serra were investigated by headspace solid phase microextraction (HS-SPME) and simultaneous-distillation extraction (SDE). The HS-SPME technique was previously evaluated to optimise sampling conditions. A total of 56 and 48 compounds including alcohols, aldehydes, hydrocarbons, ketones, carboxylic acid, ester, and aromatics were identified in leaf and stem by optimised HS-SPME method (CAR/PDMS fibre; incubation time, 10 min; extraction temperature, 50°C; extraction time, 40 min), respectively. 1-Octen-3-ol and (2E)-hexenal had significant contribution to R. serra aroma. Cluster analysis indicated that leaf and stem exhibited different volatile diversity. Air drying was favourable for the retention of the volatiles, while freeze- and sun-drying led to the loss of volatiles. SDE method preferred to the analysis of compounds with low volatility including fatty acids and esters. HS-SPME was a useful technique for the analysis of readily volatile components for the characteristics of R. serra aroma.

  15. Direct analysis of volatile fatty acids in marine sediment porewater by two-dimensional ion chromatography-mass spectrometry

    DEFF Research Database (Denmark)

    Glombitza, Clemens; Pedersen, Jeanette; Røy, Hans

    2014-01-01

    Volatile fatty acids (VFAs) are key intermediates in the microbial food web. However, the analysis of low concentrations of VFAs in marine porewater is hampered by interference from high concentrations of inorganic ions. Published methods often use sample pretreatment, including distillation...... or derivatization, to overcome this problem. This is not only labor intensive but also increases the risk of contamination. We have developed an analytical procedure that enables the direct quantification of several VFAs (formate, acetate, propionate, butyrate, valerate, pyruvate, and lactate) in marine porewater...

  16. Collection and Integration of Local Knowledge and Experience through a Collective Spatial Analysis

    Directory of Open Access Journals (Sweden)

    Juan Daniel Castillo-Rosas

    2017-01-01

    Full Text Available This article discusses the convenience of adopting an approach of Collective Spatial Analysis in the P/PGIS processes, with the aim of improving the collection and integration of knowledge and local expertise in decision-making, mainly in the fields of planning and adopting territorial policies. Based on empirical evidence, as a result of the review of scientific articles from the Web of Science database, in which it is displayed how the knowledge and experience of people involved in decision-making supported by P/PGIS are collected and used, a prototype of a WEB-GSDSS application has been developed. This prototype allows a group of people to participate anonymously, in an asynchronous and distributed way, in a decision-making process to locate goods, services, or events through the convergence of their views. Via this application, two case studies for planning services in districts of Ecuador and Italy were carried out. Early results suggest that in P/PGIS local and external actors contribute their knowledge and experience to generate information that afterwards is integrated and analysed in the decision-making process. On the other hand, in a Collective Spatial Analysis, these actors analyse and generate information in conjunction with their knowledge and experience during the process of decision-making. We conclude that, although the Collective Spatial Analysis approach presented is in a subjective and initial stage, it does drive improvements in the collection and integration of knowledge and local experience, foremost among them is an interdisciplinary geo-consensus.

  17. Analysis of the hygroscopic and volatile properties of ammonium sulphate seeded and unseeded SOA particles

    Directory of Open Access Journals (Sweden)

    N. K. Meyer

    2009-01-01

    Full Text Available The volatile and hygroscopic properties of ammonium sulphate seeded and unseeded secondary organic aerosol (SOA derived from the photo-oxidation of atmospherically relevant concentrations of α-pinene were studied. The seed particles were electrospray generated ammonium sulphate ((NH42SO4 having diameters of approximately 33 nm with a quasi-mono-disperse size distribution (geometric standard deviation σg=1.3. The volatile and hygroscopic properties of both seeded and unseeded SOA were simultaneously measured with a VH-TDMA (volatility – hygroscopicity tandem differential mobility analyzer. VH-TDMA measurements of unseeded SOA show a decrease in the hygroscopic growth (HGF factor for increased volatilisation temperatures such that the more volatile compounds appear to be more hygroscopic. This is opposite to the expected preferential evaporation of more volatile but less hygroscopic material, but could also be due to enhanced oligomerisation occurring at the higher temperature in the thermodenuder. In addition, HGF measurements of seeded SOA were measured as a function of time at two relative humidities, below (RH 75% and above (RH 85% the deliquescence relative humidity (DRH of the pure ammonium sulphate seeds. As these measurements were conducted during the onset phase of photo-oxidation, during particle growth, they enabled us to find the dependence of the HGF as a function of the volume fraction of the SOA coating. HGF's measured at RH of 85% showed a continuous decrease as the SOA coating thickness increased. The measured growth factors show good agreements with ZSR predictions indicating that, at these RH values, there are only minor solute-solute interactions. At 75% RH, as the SOA fraction increased, a rapid increase in the HGF was observed indicating that an increasing fraction of the (NH42SO4 is subject to a phase transition, going into solution, with an

  18. Multi-volatile method for aroma analysis using sequential dynamic headspace sampling with an application to brewed coffee.

    Science.gov (United States)

    Ochiai, Nobuo; Tsunokawa, Jun; Sasamoto, Kikuo; Hoffmann, Andreas

    2014-12-05

    A novel multi-volatile method (MVM) using sequential dynamic headspace (DHS) sampling for analysis of aroma compounds in aqueous sample was developed. The MVM consists of three different DHS method parameters sets including choice of the replaceable adsorbent trap. The first DHS sampling at 25 °C using a carbon-based adsorbent trap targets very volatile solutes with high vapor pressure (>20 kPa). The second DHS sampling at 25 °C using the same type of carbon-based adsorbent trap targets volatile solutes with moderate vapor pressure (1-20 kPa). The third DHS sampling using a Tenax TA trap at 80 °C targets solutes with low vapor pressure (aroma compounds for each DHS sampling and the combined MVM procedure were evaluated as a function of vapor pressure in the range of 0.000088-120 kPa. The MVM provided very good recoveries in the range of 91-111%. The method showed good linearity (r2>0.9910) and high sensitivity (limit of detection: 1.0-7.5 ng mL(-1)) even with MS scan mode. The feasibility and benefit of the method was demonstrated with analysis of a wide variety of aroma compounds in brewed coffee. Ten potent aroma compounds from top-note to base-note (acetaldehyde, 2,3-butanedione, 4-ethyl guaiacol, furaneol, guaiacol, 3-methyl butanal, 2,3-pentanedione, 2,3,5-trimethyl pyrazine, vanillin, and 4-vinyl guaiacol) could be identified together with an additional 72 aroma compounds. Thirty compounds including 9 potent aroma compounds were quantified in the range of 74-4300 ng mL(-1) (RSD<10%, n=5).

  19. Perchlorate and Volatiles of the Brine of Lake Vida (Antarctica): Implication for the in Situ Analysis of Mars Sediments

    Science.gov (United States)

    Kenig, Fabien; Chou, Luoth; McKay, Christopher P.; Jackson, W. Andrew; Doran, Peter T.; Murray, Alison E.; Fritsen, Christian H.

    2016-01-01

    The cold (-13.4 C), cryoencapsulated, anoxic, interstitial brine of the 27 m-thick ice of Lake Vida (Victoria Valley, Antarctica) contains 49 microgram L-1 of perchlorate and 11 microgram L-1 of chlorate. Lake Vida brine (LVBr) may provide an analog for potential oxychlorine-rich subsurface brine on Mars. LVBr volatiles were analyzed by solid-phase microextraction (SPME) gas chromatography-mass spectrometry (GC-MS) with two different SPME fibers. With the exception of volatile organic sulfur compounds, most other volatiles observed were artifacts produced in the GC injector when the thermal decomposition products of oxychlorines reacted with reduced carbon derived from LVBr and the SPME fiber phases. Analysis of MilliQ water with perchlorate (40 microgram L-1) showed low level of organic artifacts, reflecting carbon limitation. In order to observe sample-derived organic compounds, both in analog samples and on Mars, the molar abundance of reduced carbon in a sample must exceed those of O2 and Cl2 produced during decomposition of oxychlorines. This suggests that the abundance of compounds observed by the Sample Analysis at Mars (SAM) instruments in Sheepbed samples (CB-3, CB5, and CB6) may be controlled by an increase in the reduced-carbon/oxychlorine ratio of these samples. To increase chances of in situ detection of Martian organics during pyrolysis-GC-MS, we propose that the derivatization agents stored on SAM may be used as an external source of reduced carbon, increasing artificially the reduced-carbon to perchlorate ratio during pyrolysis, allowing the expression of more abundant and perhaps more diverse Martian organic matter.

  20. Perchlorate and volatiles of the brine of Lake Vida (Antarctica): Implication for the in situ analysis of Mars sediments

    Science.gov (United States)

    Kenig, Fabien; Chou, Luoth; McKay, Christopher P.; Jackson, W. Andrew; Doran, Peter T.; Murray, Alison E.; Fritsen, Christian H.

    2016-07-01

    The cold (-13.4°C), cryoencapsulated, anoxic, interstitial brine of the >27 m thick ice of Lake Vida (Victoria Valley, Antarctica) contains 49 µg · L-1 of perchlorate and 11 µg · L-1 of chlorate. Lake Vida brine (LVBr) may provide an analog for potential oxychlorine-rich subsurface brine on Mars. LVBr volatiles were analyzed by solid-phase microextraction (SPME) gas chromatography-mass spectrometry (GC-MS) with two different SPME fibers. With the exception of volatile organic sulfur compounds, most other volatiles observed were artifacts produced in the GC injector when the thermal decomposition products of oxychlorines reacted with reduced carbon derived from LVBr and the SPME fiber phases. Analysis of MilliQ water with perchlorate (40 µg · L-1) showed low level of organic artifacts, reflecting carbon limitation. In order to observe sample-derived organic compounds, both in analog samples and on Mars, the molar abundance of reduced carbon in a sample must exceed those of O2 and Cl2 produced during decomposition of oxychlorines. This suggests that the abundance of compounds observed by the Sample Analysis at Mars (SAM) instruments in Sheepbed samples (CB-3, CB5, and CB6) may be controlled by an increase in the reduced-carbon/oxychlorine ratio of these samples. To increase chances of in situ detection of Martian organics during pyrolysis-GC-MS, we propose that the derivatization agents stored on SAM may be used as an external source of reduced carbon, increasing artificially the reduced-carbon to perchlorate ratio during pyrolysis, allowing the expression of more abundant and perhaps more diverse Martian organic matter.

  1. Elicitors of tansy volatiles from cotton leafworm larval oral secretion.

    Science.gov (United States)

    Mack, Lienhard; Gros, Petra; Burkhardt, Jens; Seifert, Karlheinz

    2013-12-01

    The feeding of Spodoptera littoralis and Autographa gamma caterpillars on tansy leaves led to a complete different release of volatile monoterpenes, sesquiterpenes, and hexenyl alkanoates. Volatiles were collected from S. littoralis and A. gamma larvae damaged, mechanically wounded, and excised tansy leaves by closed loop stripping analysis. The qualitative and quantitative determination of the volatiles were done by GC-MS- and GC-measurements. The oligosaccharides sucrose, raffinose, stachyose, and verbascose have been detected in oral secretion of the caterpillars of the cotton leafworm S. littoralis. When applied to damaged leaves of tansy plants, these oligosaccharides induce the tansy leaves to emit a similar volatile blend as the feeding of S. littoralis larvae.

  2. Sensory analysis and volatile compounds of olive oil (cv. Cobrançosa from different irrigation regimes

    Directory of Open Access Journals (Sweden)

    Fernandes-Silva, A. A.

    2013-03-01

    Full Text Available The aim of this study was to assess the effect of different irrigation strategies on the sensory quality of virgin olive oil (VOO from the cv. “cobrançosa” integrated into a protected denomination of origin of “Azeite de Trás-os-Montes” in the Northeast of Portugal. Three irrigation treatments were applied: (T2-full irrigation, which received a seasonal water equivalent of 100% of the estimated crop evapotranspiration (ETc, (T1-continuous deficit irrigation (30% ETc and (T0- rainfed treatment. Data were collected from two consecutive crop years (2005-2006. Olive oil samples were analyzed for volatiles by GC-MS and the results compared with sensory evaluation data. Total volatile compounds tended to decrease with the amount of water applied. The characteristics pungent and bitter were more pronounced in olive oils from T0 and T1, which had higher polyphenolic concentrations, with a strong positive relationship with this variable and the bitter attribute. The Principal Components Analysis clearly separates the three olive oils from 2005, the driest year, and aggregates into a single group the three samples from 2006, suggesting no effect of irrigation on volatile compounds in years with a rainy spring and a marked effect in years with severe drought, suggesting that the effect of the trees’ water status on these variables occurs throughout the crop season and not just during the oil accumulation phase. In general, olive oil from the cv. Cobrançosa is more bitter than pungent and has a typical nutty sensory attribute shown by a strong positive relationship between benzaldehyde and the sensory notes of almonds and nuts.

    Este estudio tiene como objetivo evaluar el efecto de distintas estrategias de riego en la composición relativa de los compuestos volátiles y en la calidad sensorial. El experimento se realizó en el Noreste de Portugal, dentro de la denominación de origen protegida “Azeites de Tr

  3. Using Formal Concept Analysis to Create Pathways through Museum Collections

    DEFF Research Database (Denmark)

    Wray, Tim; Eklund, Peter

    2014-01-01

    This paper presents A Place for Art - an iPad app that allows users to explore an art collection via semantically linked pathways that are generated using Formal Concept Analysis. The app embraces the information seeking approach of exploration and is based on the idea that showing context...... and relationships among objects in a museum collection augments an interpretive experience. The fundamental interaction metaphor inherent in A Place for Art relies on Formal Concept Analysis so the interface has embedded within it the semantic clustering features of machine learning in artificial intelligence....

  4. A novel inlet system for on-line chemical analysis of semi-volatile submicron particulate matter

    Directory of Open Access Journals (Sweden)

    P. Eichler

    2014-09-01

    Full Text Available We herein present the concept of a novel modular inlet system that allows using gas-phase analyzers for on-line chemical characterization of semi-volatile submicron particles. The "chemical analysis of aerosol on-line" (CHARON inlet consists of a gas-phase denuder for stripping off gas-phase analytes, an aerodynamic lens for particle enrichment in the sampling flow and a thermo-desorption unit for particle volatilization prior to chemical analysis. We coupled the CHARON inlet to a proton-transfer-reaction time-of-flight mass spectrometer (PTR-ToF-MS which quantitatively detects most organic analytes and ammonia. The combined set-up measures submicron organic and ammonium nitrate/sulfate particles online. Two proof-of-principle studies were carried out for demonstrating the analytical power of the new set-up in analyzing primarily emitted and secondarily generated particles. Oxygenated organics and their partitioning between the gas and the particulate phase were observed from the reaction of limonene with ozone. Abundant quasi-molecular ions of organic particulate constituents were observed when submicron particles were sampled from diluted mainstream cigarette smoke.

  5. Sample Integrity Evaluation and EPA Method 325b Interlaboratory Comparison for Select Volatile Organic Compounds Collected Diffusively on Carbopack X Sorbent Tubes

    Science.gov (United States)

    Sample integrity evaluations and inter-laboratory comparisons were conducted in application of U.S. Environmental Protection Agency (EPA) Methods 325A/B for monitoring benzene and additional selected volatile organic compounds (VOCs) usingpassive-diffusive Carbopack X tube sample...

  6. Analysis of Volatile Components of Plum%梅果挥发性成分分析

    Institute of Scientific and Technical Information of China (English)

    贾卫民; 王之建; 吴晓红; 苗彩芬; 魏玉琪; 李琼

    2011-01-01

    The volatile components of plum were identified by method of HS-SFME -GC-MS. There were 66 volatile compounds, including 8 alcohols,4 lactones,12 aldehydes,23 esters,2 ketones,8 acids,7 terpenes and terpene alcohols and 2 aromatic compounds. The reason was analyzed why plum sends forth the aromas of peach,milk and apricot in the early,middle and late stages of aroma production.%采用顶空固相微萃取-气质联用法分析了梅果的挥发性成分,共鉴定出66种挥发性成分,其中醇类8种、内酯类4种、醛类12种、酯类23种、酮类2种、酸类8种、萜烯及萜烯醇类7种以及其他芳香族类化合物2种.分析了梅果发香前、中和后期分别具有桃香、果香奶香和杏香的原因.

  7. Comparative Analysis of the Volatile Components in the Fresh Roots and Rhizomes of Curcuma wenyujin by Static Headspace Gas Chromatography Mass Spectrometry

    Institute of Scientific and Technical Information of China (English)

    FANG Fang; CHENG Zhi-Hong; GUO Yin-Long; CAI Yan-Ben

    2006-01-01

    Static headspace GC-MS method coupled with H/D exchange was firstly developed to determine and identify the volatile components in the fresh root and rhizome of Curcuma wenyujin. The TIC chromatograms of 3 batches of fresh roots harvested at different time showed significant difference in the volatile components: the constitution was the same but the content of them was different. More than 60 volatile components in fresh roots (Root of C.wenyujin) and rhizomes (Rhizome of C. wenyujin) of C. wenyujin were detected, of which 51 and 48 volatile components were identified respectively. The fresh roots and rhizomes of C. wenyujin were found to have the similar volatile components. The contents of these components were calibrated by the response of β-elemene. In addition,the principal active component, β-elemene, was further confirmed and relatively quantified by its standard.γ-terpinene showed obvious allylic hydrogen/deuterium exchange using deuterium oxide which gave a new method to identify some compounds containing allylic hydrogen. At the same time, the active hydrogen compounds were also further confirmed. The results show that HS-GC-MS method is a fast, simple and efficient way for the analysis of volatile components from medical plants.

  8. DETERMINATION OF SATURATION VAPOR PRESSURE OF LOW VOLATILE SUBSTANCES THROUGH THE STUDY OF EVAPORATION RATE BY THERMOGRAVIMETRIC ANALYSIS

    Directory of Open Access Journals (Sweden)

    R. V. Ralys

    2015-11-01

    Full Text Available Subject of Study.Research of vapor pressure of low volatile substances is a complicated problem due to both direct experimental implementation complexity and, most significantly, the issues faced correctness of the analysis and processing of experimental data. That is why it is usually required engaging the reference substances (with vapor pressures well studied. The latter drastically reduces the effectiveness of the experimental methods used and narrows their applicability. The paper deals with an approach to the evaporation process description (sublimation of low volatile substances based on molecular kinetic description in view of diffusive and convection processes. The proposed approach relies on experimental thermogravimetricfindingsina wide range of temperatures, flow rates ofthe purge gas and time. Method. A new approach is based on the calculation of the vapor pressure and uses the data about the speed of evaporation by thermogravimetric analysis depending on the temperature, the flow rate of the purge gas, and the evaporation time. The basis for calculation is the diffusion-kinetic description of the process of evaporation (mass loss of the substance from the exposed surface. The method is applicable to determine the thermodynamic characteristics for both the evaporation (the equilibrium liquid - vapor and sublimation (the equilibrium solid - vapor. We proposed the appropriate method of the experiment and analysis of its data in order to find the saturated vapor pressure of individual substances of low volatility. Main Results. The method has been tested on substances with insufficiently reliable and complete study of the thermodynamic characteristics but, despite this, are often used (because of the other data limitations as reference ones. The vaporization process (liquid-vapor has been studied for di-n-butyl phthalate C16H22O4 at 323,15–443,15 К, and sublimation for benzoic acid C7H6O2at 303,15–183,15 К. Both processes have

  9. Local Citation Analysis of Graduate Biology Theses: Collection Development Implications

    Science.gov (United States)

    Miller, Laura Newton

    2011-01-01

    This paper will focus on the citation analysis of graduate masters theses from Carleton University's Biology Department with implications for library collection management decisions. Twenty-five masters theses were studied to determine citation types and percentages, ranking of journals by frequency of citation and by number of authors citing, and…

  10. Using Formal Concept Analysis to Create Pathways through Museum Collections

    DEFF Research Database (Denmark)

    Wray, Tim; Eklund, Peter

    2014-01-01

    and relationships among objects in a museum collection augments an interpretive experience. The fundamental interaction metaphor inherent in A Place for Art relies on Formal Concept Analysis so the interface has embedded within it the semantic clustering features of machine learning in artificial intelligence....

  11. RICE PRICE VOLATILITY IN EAST JAVA

    Directory of Open Access Journals (Sweden)

    Wati R.Y.E.

    2017-09-01

    Full Text Available The purpose of the research is analyzing the volatility and volatility spillover of monthly price of paddy at the level of farmers and consumers in 2010-2016. ARCH/GARCH used to analyze volatility and GARCH BEKK-model is used to analyze the volatility spillover. The results of the analysis show that price volatility at the farmer level is very high (extremely high volatility, price volatility at the consumer level is low (low volatility, and volatility spillover does not occur between the farmers and the consumers market. The need to guarantee an effective floor price as well as information disclosure related to the market commodity prices so that the pattern of prices transmission among interrelated markets can be symmetrical.

  12. Peak alignment and robust principal component analysis of gas chromatograms of fatty acid methyl esters and volatiles

    DEFF Research Database (Denmark)

    Frosch, Stina; Jørgensen, Bo

    2007-01-01

    Gas chromatograms of fatty acid methyl esters and of volatile lipid oxidation products from fish lipid extracts are analyzed by multivariate data analysis [principal component analysis (PCA)]. Peak alignment is necessary in order to include all sampled points of the chromatograms in the data set....... The ability of robust algorithms to deal with outlier problems, including both sample-wise and element-wise outliers, and the advantages and drawbacks of two robust PCA methods, robust PCA (ROBPCA) and robust singular value decomposition when analysing these GC data were investigated. The results show...... that the usage of ROPCA is advantageous, compared with traditional PCA, when analysing the entire profile of chromatographic data in cases of sub-optimally aligned data. It also demonstrates how choosing the most robust PCA (sample or element-wise) depends on the type of outliers present in the data set....

  13. Analysis of volatile organic compounds liberated and metabolised by human umbilical vein endothelial cells (HUVEC) in vitro.

    Science.gov (United States)

    Mochalski, Paweł; Theurl, Markus; Sponring, Andreas; Unterkofler, Karl; Kirchmair, Rudolf; Amann, Anton

    2015-01-01

    Gas chromatography with mass spectrometric detection combined with head-space needle trap extraction as the pre-concentration technique was applied to identify and quantify volatile organic compounds released or metabolised by human umbilical vein endothelial cells. Amongst the consumed species there were eight aldehydes (2-methyl 2-propenal, 2-methyl propanal, 2-methyl butanal, 3-methyl butanal, n-hexanal, benzaldehyde, n-octanal and n-nonanal) and n-butyl acetate. Further eight compounds (ethyl acetate, ethyl propanoate, ethyl butyrate, 3-heptanone, 2-octanone, 2-nonanone, 2-methyl-5-(methylthio)-furan and toluene) were found to be emitted by the cells under study. Possible metabolic pathways leading to the uptake and release of these compounds by HUVEC are proposed and discussed. The uptake of aldehydes by endothelial cells questions the reliability of species from this chemical class as breath or blood markers of disease processes in human organism. The analysis of volatiles released or emitted by cell lines is shown to have a potential for the identification and assessment of enzymes activities and expression.

  14. Collective Thomson scattering data analysis for Wendelstein 7-X

    DEFF Research Database (Denmark)

    Abramovic, I.; Pavone, A.; Svensson, J.

    2017-01-01

    Collective Thomson scattering (CTS) diagnostic is being installed on the Wendelstein 7-X stellarator to measure the bulk ion temperature in the upcoming experimental campaign. In order to prepare for the data analysis, a forward model of the diagnostic (eCTS) has been developed and integrated...... into the Bayesian data analysis framework Minerva. Synthetic spectra have been calculated with the forward model and inverted using Minerva in order to demonstrate the feasibility to measure the ion temperature in the presence of nuisance parameters that also influence CTS spectra. In this paper we report...... on the results of this anlysis and discuss the main sources of uncertainty in the CTS data analysis....

  15. Recovery of volatile fatty acids via membrane contactor using flat membranes: experimental and theoretical analysis.

    Science.gov (United States)

    Tugtas, Adile Evren

    2014-07-01

    Volatile fatty acid (VFA) separation from synthetic VFA solutions and leachate was investigated via the use of a membrane contactor. NaOH was used as a stripping solution to provide constant concentration gradient of VFAs in both sides of a membrane. Mass flux (12.23 g/m(2)h) and selectivity (1.599) observed for acetic acid were significantly higher than those reported in the literature and were observed at feed pH of 3.0, flow rate of 31.5 ± 0.9 mL/min, and stripping solution concentration of 1.0 N. This study revealed that the flow rate, stripping solution strength, and feed pH affect the mass transfer of VFAs through the PTFE membrane. Acetic and propionic acid separation performances observed in the present study provided a cost effective and environmental alternative due to elimination of the use of extractants.

  16. Characterization and semiquantitative analysis of volatiles in seedless watermelon varieties using solid-phase microextraction.

    Science.gov (United States)

    Beaulieu, John C; Lea, Jeanne M

    2006-10-04

    Seedless triploid watermelons have increased in popularity since the early 1990s, and the demand for seedless fruit is on the rise. Sweetness and sugars are crucial breeding focuses for fruit quality. Volatiles also play an important role; yet, we found no literature for seedless varieties and no reports using solid-phase microextraction (SPME) in watermelon. The objective of this experiment was to identify volatile and semivolatile compounds in five seedless watermelon varieties using carboxen divinylbenzene polydimethylsiloxane solid-phase microextraction (SPME) with gas chromatography-mass spectrometry (GC-MS). Fully ripe watermelon was squeezed through miracloth to produce rapid juice extracts for immediate headspace SPME GC-MS. Aldehydes, alcohols, ketones, and one furan (2-pentyl furan, a lipid oxidation product) were recovered. On the basis of total ion count peak area, the most abundant compounds in five varieties were 3-nonen-1-ol/(E,Z)-2,6-nonadienal (16.5-28.2%), (E)-2-nonenal (10.6-22.5%), and (Z)-6-nonenal (2.0-11.3%). Hexanal was most abundant (37.7%) in one variety (Petite Perfection) [corrected] The most abundant ketone was 6-methyl-5-hepten-2-one (2.7-7.7%). Some sensory attributes reported for these compounds are melon, citrus, cucumber, orange, rose, floral, guava, violet, vegetable, green, grassy, herbaceous, pungent, fatty, sweet, and waxy. Identifying and relating these compounds to sensory attributes will allow for future monitoring of the critical flavor compounds in seedless watermelon after processing and throughout fresh-cut storage.

  17. Analysis of Volatile Markers for Virgin Olive Oil Aroma Defects by SPME-GC/FID: Possible Sources of Incorrect Data.

    Science.gov (United States)

    Oliver-Pozo, Celia; Aparicio-Ruiz, Ramón; Romero, Inmaculada; García-González, Diego L

    2015-12-09

    The need to explain virgin olive oil (VOO) aroma descriptors by means of volatiles has raised interest in applying analytical techniques for trapping and quantitating volatiles. Static headspace sampling with solid phase microextraction (SPME) as trapping material is one of the most applied solutions for analyzing volatiles. The use of an internal standard and the determination of the response factors of the main volatiles seem to guarantee the correct determination of volatile concentrations in VOOs by SPME-GC/FID. This paper, however, shows that the competition phenomena between volatiles in their adsorption to the SPME fiber, inherent in static headspace sampling, may affect the quantitation. These phenomena are more noticeable in the particular case of highly odorant matrices, such as rancid and vinegary VOOs with high intensity of defect. The competition phenomena can modify the measurement sensitivity, which can be observed in volatile quantitation as well as in the recording of internal standard areas in different matrices. This paper analyzes the bias of the peak areas and concentrations of those volatiles that are markers for each sensory defect of VOOs (rancid, vinegary, musty, and fusty) when the intensity and complexity of aroma are increased. Of the 17 volatile markers studied in this work, 10 presented some anomalies in the quantitation in highly odorant matrices due the competition phenomena. However, quantitation was not affected in the concentration ranges at which each volatile marker is typically found in the defective oils they were characteristic of, validating their use as markers.

  18. Multilateral analysis of increasing collective dose and new ALARA programme.

    Science.gov (United States)

    Oumi, Tadashi; Morii, Yasuki; Imai, Toshirou

    2011-07-01

    JAPC (The Japan Atomic Power Company) is the only electric power company that operates different types of nuclear reactors in Japan; it operates two BWRs (boiling water reactors), one pressurised water reactor and one gas cooled reactor. JAPC has been conducting various activities aimed at reducing radiation dose received by workers for over 45 y. Recently, the collective dose resulting from periodic maintenance has increased at each plant because of the replacement of large equipment and the unexpected extension of the outage period. In particular, the collective dose at Tokai-2 is one of the highest among Japanese BWR plants((1)), owing to the replacement and strengthening of equipment to meet earthquake-proof requirements. In this study, the authors performed a multilateral analysis of unacceptably a large collective dose and devised a new ALARA programme that includes a 3D dose prediction map and the development of machines to assist workers.

  19. Volatility-constrained multifractal detrended cross-correlation analysis: Cross-correlation among Mainland China, US, and Hong Kong stock markets

    Science.gov (United States)

    Cao, Guangxi; Zhang, Minjia; Li, Qingchen

    2017-04-01

    This study focuses on multifractal detrended cross-correlation analysis of the different volatility intervals of Mainland China, US, and Hong Kong stock markets. A volatility-constrained multifractal detrended cross-correlation analysis (VC-MF-DCCA) method is proposed to study the volatility conductivity of Mainland China, US, and Hong Kong stock markets. Empirical results indicate that fluctuation may be related to important activities in real markets. The Hang Seng Index (HSI) stock market is more influential than the Shanghai Composite Index (SCI) stock market. Furthermore, the SCI stock market is more influential than the Dow Jones Industrial Average stock market. The conductivity between the HSI and SCI stock markets is the strongest. HSI was the most influential market in the large fluctuation interval of 1991 to 2014. The autoregressive fractionally integrated moving average method is used to verify the validity of VC-MF-DCCA. Results show that VC-MF-DCCA is effective.

  20. Automated data collection and analysis system for MOSFET radiation detectors.

    Science.gov (United States)

    Gladstone, D J; Chin, L M

    1991-01-01

    Metal oxide semiconductor field effect transistors (MOSFET) have been used as radiation dosimeters. Because of their small detector size, minimal power requirements, and signal integration characteristics, they offer unique possibilities as real-time dose monitors in radiotherapy. An automated data collection and analysis system for use with MOSFET radiation dosimeters has been designed and built. The objective was to design a system which can acquire and process the MOSFET signals in real time, in any radiation field encountered in radiotherapy. In particular, major problems have been solved arising from the intrinsic drifts of the MOSFET signal during low dose rate measurements. These signal drifts are significant when the MOSFET detector is used in applications such as on-line monitoring of radiation dose delivery in brachytherapy or radioimmunotherapy. The data collection and analysis system includes a portable IBM-compatible personal computer fitted with digital-to-analog and analog-to-digital converter boards. A single-chip programmable current supply is used to power the MOSFET dosimeters. Intrinsic and extrinsic drifts in signal due to ion diffusion and electron tunneling are corrected by deconvolution of the collected data in real time or after data collection. The data acquisition system and signal-processing methodologies are described.

  1. Collection and analysis of offshore workforce audiometry data

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-05-01

    This report summarises the results of a study analysing audiometry data to determine if noise induced related hearing loss is happening in offshore operations. The background to the study is traced, and details are given of the initial contacts with medical and operational companies holding audiometry data, the confidentiality of the data sources, the questionnaire for the holders of personnel audiometry data, and initial data checking. A descriptive analysis of the study population is presented, and the analysis of audiometry data, hearing threshold levels, and the classification of the data using the Health and Safety Executive (HSE) categorisation scheme are discussed. The questionnaire for the data holders, the audiometry data collection proforma, and guidance for completion of data collection proformas are included in appendices.

  2. Dynamic headspace analysis of the release of volatile organic compounds from ethanolic systems by direct APCI-MS.

    Science.gov (United States)

    Tsachaki, Maroussa; Linforth, Robert S T; Taylor, Andrew J

    2005-10-19

    Static equilibrium headspace was diluted with a stream of nitrogen to study the stability of the volatile headspace concentration. The headspace dilution profile of 18 volatile compounds above aqueous and ethanolic solutions was measured in real time using atmospheric pressure chemical ionization-mass spectrometry. Under dynamic conditions the volatiles headspace concentration above water solutions decreased readily upon dilution. The presence of ethanol helped to maintain the volatile headspace concentration when the ethanol solution concentration was above 50 mL/L. This effect was such that under dynamic conditions the absolute volatile concentration above an ethanolic solution was higher than that above an aqueous solution, contrary to results observed in equilibrium studies. The ratio of the headspace concentration of volatiles above ethanolic 120 mL/L and water solutions was correlated to their air/water partition coefficient.

  3. Comparative Analysis of Volatile Composition in Chinese Truffles via GC × GC/HR-TOF/MS and Electronic Nose

    Directory of Open Access Journals (Sweden)

    Ning Zhang

    2016-04-01

    Full Text Available To compare the volatile compounds of Chinese black truffle and white truffle from Yunnan province, this study presents the application of a direct solvent extraction/solvent-assisted flavor evaporation (DSE-SAFE coupled with a comprehensive two-dimensional gas chromatography (GC × GC high resolution time-of-flight mass spectrometry (HR-TOF/MS and an electronic nose. Both of the analytical methods could distinguish the aroma profile of the two samples. In terms of the overall profile of truffle samples in this research, more kinds of acids were detected via the method of DSE-SAFE. Besides, compounds identified in black truffle (BT, but not in white truffle (WT, or vice versa, and those detected in both samples at different levels were considered to play an important role in differentiating the two samples. According to the analysis of electronic nose, the two samples could be separated, as well.

  4. Tripartite analysis across business cycles in Turkey: A multi-timescale inquiry of efficiency, volatility and integration

    Directory of Open Access Journals (Sweden)

    Shaista Arshad

    2014-12-01

    Full Text Available In the current era of globalization, deregulation and liberalization of markets have led to financial integration amongst developing and developed countries. The sudden massive inflow of capital into developing country's stock markets begs the question of whether or not the markets are sufficiently efficient to handle the increasing integration of markets. Furthermore, the relationship between the integration and efficiency of stock markets tends to be of greater importance during economic downturns. Taking Turkey as a case study owing to its economic growth and importance in two successful blocs, i.e. the EU and the OIC, we attempt to analyse the linkages between stock market efficiency and integration during the different phases of the economy. The findings of our study provide an interesting insight into the relative improvement in volatility, efficiency and integration across business cycles, in a multi time scale analysis.

  5. Comparative Analysis of the Volatile Components of Agrimonia eupatoria from Leaves and Roots by Gas Chromatography-Mass Spectrometry and Multivariate Curve Resolution

    Directory of Open Access Journals (Sweden)

    Xiao-Liang Feng

    2013-01-01

    Full Text Available Gas chromatography-mass spectrometry and multivariate curve resolution were applied to the differential analysis of the volatile components in Agrimonia eupatoria specimens from different plant parts. After extracted with water distillation method, the volatile components in Agrimonia eupatoria from leaves and roots were detected by GC-MS. Then the qualitative and quantitative analysis of the volatile components in the main root of Agrimonia eupatoria was completed with the help of subwindow factor analysis resolving two-dimensional original data into mass spectra and chromatograms. 68 of 87 separated constituents in the total ion chromatogram of the volatile components were identified and quantified, accounting for about 87.03% of the total content. Then, the common peaks in leaf were extracted with orthogonal projection resolution method. Among the components determined, there were 52 components coexisting in the studied samples although the relative content of each component showed difference to some extent. The results showed a fair consistency in their GC-MS fingerprint. It was the first time to apply orthogonal projection method to compare different plant parts of Agrimonia eupatoria, and it reduced the burden of qualitative analysis as well as the subjectivity. The obtained results proved the combined approach powerful for the analysis of complex Agrimonia eupatoria samples. The developed method can be used to further study and quality control of Agrimonia eupatoria.

  6. [Analysis of the chemical constituents of volatile oil from the Folium Rhododendri Daurici by supercritical CO2 extraction].

    Science.gov (United States)

    Jiao, Shu-qing; Liu, Feng-hua

    2009-02-01

    To compare the chemical constituents of volatile oils from Folium Rhododendri Daurici between supercritical CO2 extraction (SCE-CO2) and steam distillation (SD). The chemical constituents of volatile oils obtained by two methods were analyzed by GC-MS. 52 compounds in the volatile oil extracted by SCE-CO2 and 48 compounds in the volatile oil extracted by SD were separated and identified separately. There were 45 same components. The chemical constituents obtained by SCE-CO2 and SD are approached.

  7. [Analysis of volatile constituents in leaves of three cypress species by gas chromatography/mass spectrometry].

    Science.gov (United States)

    Hao, Dejun; Zhang, Yonghui; Dai, Huaguo; Wang, Yan

    2006-03-01

    Volatile oils in leaves of three cypress species were extracted by hydrodistillation method and analyzed by gas chromatography/mass spectrometry. Sixty-four constituents were separated and identified. The majority of the components were found to be monoterpenes and sesquiterpenes. There were 33, 37, 37 compounds in the oils of leaves of Sabina chinensis (L.) Ant, Cupressus lusitanica 'zhongshan' Mill and Sabina chinensis (L.) Ant. Cv. Kaizuca, respectively. Fourteen compounds were common to them, which were thujene, alpha-pinene, camphene, sabinene, beta-myrcene, alpha-terpinene, gamma-terpinene, alpha-terpinolene, bornyl acetate, beta-elemene, alpha-amorphene, germacrene D, delta-cadinene and elemol. In addition, each species had particular compounds. The main components were found to be: sabinene (20.99%), limonene (19.78%) and bornyl acetate (11.68%) for Sabina chinensis (L.) Ant; alpha-pinene (10.39%), sabinene (11.19%) and delta-3-carene (8.88%) for Cupressus lusitanica 'zhongshan' Mill; limonene (24.56%), beta-myrcene (8.04%) for Sabina chinensis (L.) Ant. Cv. Kaizuca.

  8. River water quality analysis via headspace detection of volatile organic compounds

    Science.gov (United States)

    Tang, Johnny Jock Lee; Nishi, Phyllis Jacqueline; Chong, Gabriel Eng Wee; Wong, Martin Gideon; Chua, Hong Siang; Persaud, Krishna; Ng, Sing Muk

    2017-03-01

    Human civilization has intensified the interaction between the community and the environment. This increases the threat on the environm ent for being over exploited and contaminated with m anmade products and synthetic chemicals. Of all, clean water is one of the resources that can be easily contaminated since it is a universal solvent and of high mobility. This work reports the development and optimization of a water quality monitoring system based on metal oxide sensors. The system is intended to a ssist the detection of volatile organic compounds (VOCs) present in water sources online and onsite. The sampling mechanism was based on contactless mode, where headspace partial pressure of the VOCs formed above the water body in a close chamber was drawn for detection at the sensor platform. Pure toluene was used as standard to represent the broad spectrum of VOCs, and the sensor dynamic range was achieved from 1-1000 ppb. Several sensing parameters such as sampling time, headspace volume, and sensor recovery were s tudied and optimized. Besides direct detection of VOC contaminants in the water, the work has also been extended to detect VOCs produced by microbial communities and to c orrelate the size of the communities with the reading of V OCs recorded. This can serve to give b etter indication of water quality, not only on the conce ntration of VOCs c ontamination from chemicals, but also the content of microbes, which some can have severe effect on human health.

  9. Integrated gas chromatography for ultrafast analysis of volatile organic compounds in air.

    Science.gov (United States)

    Zhang, Yanggang; Wu, Dapeng; Yan, Xiaohui; Ding, Kun; Guan, Yafeng

    2016-07-01

    An integrated instrumentation of a cryogenic microtrap-thermal desorption-low thermal mass (LTM) fast gas chromatographic (GC) system had been designed and evaluated for the ultrafast enrichment and separation of trace amounts of highly volatile organic compounds (VOCs) in air. The LTM fast GC column was wrapped uniformly on outer surface of a thin metal heating cylinder of 65mm O.D. and 0.5mm in thickness. Both of microtrap and LTM column could be rapidly cooled by liquid CO2 down to -35°C, and heated by resistive heating. A 10m×100µm i.d. micro-bore capillary column was used in the LTM GC column module to provide a high separation speed. Key operational parameters, including adsorbent mass, trapping temperature, thermal desorption temperature and injection time were optimized. Under the optimized condition, the 39 species of TO-14 VOCs were well resolved and quantified in less than 3min. The detection limits were in the range of 8 ppt-0.22 ppb at sampling volume of 50mL and trapping temperature of -10°C. The average peak width was 0.9s, and the peak capacity of ~150 (at unit resolution) was obtained. The applicability of the setup was evaluated by analyzing three real environmental samples, where some typical VOCs at sub ppb level were detected.

  10. Volatile profiles of members of the USDA Geneva Malus Core Collection: utility in evaluation of a hypothesized biosynthetic pathway for esters derived from 2-methylbutanoate and 2-methylbutan-1-ol.

    Science.gov (United States)

    Sugimoto, Nobuko; Forsline, Philip; Beaudry, Randolph

    2015-02-25

    The volatile ester and alcohol profiles of ripening apple fruit from 184 germplasm lines in the USDA Malus Germplasm Repository at the New York Agricultural Experiment Station in Geneva, NY, USA, were evaluated. Cluster analysis suggested biochemical relationships exist between several ester classes. A strong linkage was revealed between 2-methylbutanoate, propanoate, and butanoate esters, suggesting the influence of the recently proposed "citramalic acid pathway" in apple fruit. Those lines with a high content of esters formed from 2-methylbutan-1-ol and 2-methylbutanoate (2MB) relative to straight-chain (SC) esters (high 2MB/SC ratio) exhibited a marked increase in isoleucine and citramalic acid during ripening, but those lines with a low content did not. Thus, the data were consistent with the existence of the hypothesized citramalic acid pathway and suggest that the Geneva Malus Germplasm Repository, appropriately used, could be helpful in expanding our understanding of mechanisms for fruit volatile synthesis and other aspects of secondary metabolism.

  11. Data collection from energy certificates. Experiences and analysis. Synthesis report

    Energy Technology Data Exchange (ETDEWEB)

    Loga, Tobias; Diefenbach, Nikolaus (eds.); Popiolek, Malgorzata; Panek, Aleksander [Narodowa Agencja Poszanowania Energii S.A. (NAPE), Warsaw (Poland); Cohen, Robert [Energy for Sustainable Development Ltd (ESD), Overmoor (GB)] (and others)

    2008-03-15

    Apart from the described bottom-up approach DATAMINE also aims at drawing general conclu-sions concerning monitoring with the help of energy certificates. Of course 12 projects simultane-ously being carried out in 12 EU countries bring up the question if there is a way for a common analysis of the collected data or at least for a common understanding of the data from different projects. Against that background a harmonised data structure with 255 data fields was defined. The ''philosophy'' of this approach was as follows: Each project partner could use his own data structure and carry out his analysis in an individual way according to the objectives and conditions of his individual model project. But at the end he had to translate his data base in the harmonised data structure and to deliver it to the project coordinator IWU who collect all data in a common evaluation data base. This will make possible a cross-country comparison of the collected data - taking into consideration that because of the different types of energy certificates neither all data fields of the data structure can be filled in by the model projects nor will a comparison of all model projects be possible. So the harmonised data structure can be seen as a simplified ''common lan-guage'' that facilitates an understanding of data bases from different projects. A detailed descrip-tion of the data structure among with other general results from the first DATAMINE workpackages which were carried out before the model projects is given in the DATAMINE synthesis report ''Con-cepts for Data Collection and Analysis'' from December 2006 which is also available on the project website. (orig.)

  12. A powerful methodological approach combining headspace solid phase microextraction, mass spectrometry and multivariate analysis for profiling the volatile metabolomic pattern of beer starting raw materials.

    Science.gov (United States)

    Gonçalves, João L; Figueira, José A; Rodrigues, Fátima P; Ornelas, Laura P; Branco, Ricardo N; Silva, Catarina L; Câmara, José S

    2014-10-01

    The volatile metabolomic patterns from different raw materials commonly used in beer production, namely barley, corn and hop-derived products - such as hop pellets, hop essential oil from Saaz variety and tetra-hydro isomerized hop extract (tetra hop), were established using a suitable analytical procedure based on dynamic headspace solid-phase microextraction (HS-SPME) followed by thermal desorption gas chromatography-quadrupole mass spectrometry detection (GC-qMS). Some SPME extraction parameters were optimized. The best results, in terms of maximum signal recorded and number of isolated metabolites, were obtained with a 50/30 μm DVB/CAR/PDMS coating fiber at 40 °C for 30 min. A set of 152 volatile metabolites comprising ketones (27), sesquiterpenes (26), monoterpenes (19), aliphatic esters (19), higher alcohols (15), aldehydes (11), furan compounds (11), aliphatic fatty acids (9), aliphatic hydrocarbons (8), sulphur compounds (5) and nitrogen compounds (2) were positively identified. Each raw material showed a specific volatile metabolomic profile. Monoterpenes in hop essential oil and corn, sesquiterpenes in hop pellets, ketones in tetra hop and aldehydes and sulphur compounds in barley were the predominant chemical families in the targeted beer raw materials. β-Myrcene was the most dominant volatile metabolite in hop essential oil, hop pellets and corn samples while, in barley, the predominant volatile metabolites were dimethyl sulphide and 3-methylbutanal and, in tetra hop, 6-methyl-2-pentanone and 4-methyl-2-pentanone. Principal component analysis (PCA) showed natural sample grouping among beer raw materials.

  13. Comparison of quarter-hourly on-line dynamic headspace analysis to purge-and-trap analysis of varying volatile organic compounds in drinking water sources.

    Science.gov (United States)

    Schnable, J G; Dussert, B; Suffet, I H; Hertz, C D

    1990-07-27

    On-line dynamic headspace analysis was refined for the quarter-hourly monitoring of select volatile organic compounds (VOCs) in ground and surface waters, for extended periods of time. Hourly comparisons were made to on-line purge-and-trap analysis, and to purge-and-trap analysis after sample preservation and storage. Variations in VOC concentrations of 6047% biweekly, 222% daily, 97% hourly, and 35% quarter-hourly were observable, with the 15-min cycle of the dynamic headspace analysis. The headspace analyzer had superior retention time stability, required less maintenance, and had 1/4 the analysis time as a typical purge-and-trap-gas chromatograph system used for hourly comparisons.

  14. The Apollo lunar samples collection analysis and results

    CERN Document Server

    Young, Anthony

    2017-01-01

    This book focuses on the specific mission planning for lunar sample collection, the equipment used, and the analysis and findings concerning the samples at the Lunar Receiving Laboratory in Texas. Anthony Young documents the collection of Apollo samples for the first time for readers of all backgrounds, and includes interviews with many of those involved in planning and analyzing the samples. NASA contracted with the U.S. Geologic Survey to perform classroom and field training of the Apollo astronauts. NASA’s Geology Group within the Manned Spacecraft Center in Houston, Texas, helped to establish the goals of sample collection, as well as the design of sample collection tools, bags, and storage containers. In this book, detailed descriptions are given on the design of the lunar sampling tools, the Modular Experiment Transporter used on Apollo 14, and the specific areas of the Lunar Rover vehicle used for the Apollo 15, 16, and 17 missions, which carried the sampling tools, bags, and other related equipment ...

  15. Volatile selenium flux from the great Salt Lake, Utah

    Science.gov (United States)

    Diaz, X.; Johnson, W.P.; Oliver, W.A.; Naftz, D.L.

    2009-01-01

    The removal mechanisms that govern Se concentrations in the Great Salt Lake are unknown despite this terminal lake being an avian habitat of hemispheric importance. However, the volatilization flux of Se from the Great Salt Lake has not been previously measured due to challenges of analysis in this hypersaline environment This paper presents results from recent field studies examining the spatial distribution of dissolved volatile Se (areally and with depth) in the south arm (main body) of the Great Salt Lake. The analyses involved collection of dissolved volatile Se in a cryofocusing trap system via sparging with helium. The cryotrapped volatile Se was digested with nitric acid and analyzed by inductively coupled plasma mass spectrometry (ICP-MS). Results show concentrations of dissolved volatile Se that increase with depth in the shallow brine, suggesting that phytoplankton in the open waters and bioherms in shallow sites (transport models corrected to simulate the highly saline environment of the south arm of the Great Salt Lake. The estimated annual flux of volatile Se was 1455 kg/year within a range from 560 to 3780 kg Se/year for the 95% confidence interval and from 970 to 2180 kg Se/year within the 68% confidence interval. ?? 2009 American Chemical Society.

  16. Fluctuation behaviors of financial return volatility duration

    Science.gov (United States)

    Niu, Hongli; Wang, Jun; Lu, Yunfan

    2016-04-01

    It is of significantly crucial to understand the return volatility of financial markets because it helps to quantify the investment risk, optimize the portfolio, and provide a key input of option pricing models. The characteristics of isolated high volatility events above certain threshold in price fluctuations and the distributions of return intervals between these events arouse great interest in financial research. In the present work, we introduce a new concept of daily return volatility duration, which is defined as the shortest passage time when the future volatility intensity is above or below the current volatility intensity (without predefining a threshold). The statistical properties of the daily return volatility durations for seven representative stock indices from the world financial markets are investigated. Some useful and interesting empirical results of these volatility duration series about the probability distributions, memory effects and multifractal properties are obtained. These results also show that the proposed stock volatility series analysis is a meaningful and beneficial trial.

  17. An improved, automated whole air sampler and gas chromatography mass spectrometry analysis system for volatile organic compounds in the atmosphere

    Science.gov (United States)

    Lerner, Brian M.; Gilman, Jessica B.; Aikin, Kenneth C.; Atlas, Elliot L.; Goldan, Paul D.; Graus, Martin; Hendershot, Roger; Isaacman-VanWertz, Gabriel A.; Koss, Abigail; Kuster, William C.; Lueb, Richard A.; McLaughlin, Richard J.; Peischl, Jeff; Sueper, Donna; Ryerson, Thomas B.; Tokarek, Travis W.; Warneke, Carsten; Yuan, Bin; de Gouw, Joost A.

    2017-01-01

    Volatile organic compounds were quantified during two aircraft-based field campaigns using highly automated, whole air samplers with expedited post-flight analysis via a new custom-built, field-deployable gas chromatography-mass spectrometry instrument. During flight, air samples were pressurized with a stainless steel bellows compressor into electropolished stainless steel canisters. The air samples were analyzed using a novel gas chromatograph system designed specifically for field use which eliminates the need for liquid nitrogen. Instead, a Stirling cooler is used for cryogenic sample pre-concentration at temperatures as low as -165 °C. The analysis system was fully automated on a 20 min cycle to allow for unattended processing of an entire flight of 72 sample canisters within 30 h, thereby reducing typical sample residence times in the canisters to less than 3 days. The new analytical system is capable of quantifying a wide suite of C2 to C10 organic compounds at part-per-trillion sensitivity. This paper describes the sampling and analysis systems, along with the data analysis procedures which include a new peak-fitting software package for rapid chromatographic data reduction. Instrument sensitivities, uncertainties and system artifacts are presented for 35 trace gas species in canister samples. Comparisons of reported mixing ratios from each field campaign with measurements from other instruments are also presented.

  18. An Analysis of the Climate Data Initiative's Data Collection

    Science.gov (United States)

    Ramachandran, R.; Bugbee, K.

    2015-12-01

    The Climate Data Initiative (CDI) is a broad multi-agency effort of the U.S. government that seeks to leverage the extensive existing federal climate-relevant data to stimulate innovation and private-sector entrepreneurship to support national climate-change preparedness. The CDI project is a systematic effort to manually curate and share openly available climate data from various federal agencies. To date, the CDI has curated seven themes, or topics, relevant to climate change resiliency. These themes include Coastal Flooding, Food Resilience, Water, Ecosystem Vulnerability, Human Health, Energy Infrastructure, and Transportation. Each theme was curated by subject matter experts who selected datasets relevant to the topic at hand. An analysis of the entire Climate Data Initiative data collection and the data curated for each theme offers insights into which datasets are considered most relevant in addressing climate resiliency. Other aspects of the data collection will be examined including which datasets were the most visited or popular and which datasets were the most sought after for curation by the theme teams. Results from the analysis of the CDI collection will be presented in this talk.

  19. Comparison of PCE and TCE disappearance in heated volatile organic analysis vials and flame-sealed ampules.

    Science.gov (United States)

    Costanza, Jed; Pennell, Kurt D

    2008-02-01

    The rates of hydrolysis reported for tetrachloroethylene (PCE) and trichloroethylene (TCE) at elevated temperatures range over two orders-of-magnitude, where some of the variability may be due to the presence of a gas phase. Recent studies suggest that volatile organic analysis (VOA) vials provide a low-cost and readily available zero headspace system for measuring aqueous-phase hydrolysis rates. This work involved measuring rates of PCE and TCE disappearance and the corresponding appearance of dechlorination products in water-filled VOA vials and flame-sealed ampules incubated at 21 and 55 degrees C for up to 95.5 days. While PCE and TCE concentrations readily decreased in the VOA vials to yield first-order half lives of 11.2 days for PCE and 21.1 days for TCE at 55 degrees C, concentrations of anticipated dechlorination products, including chloride, remained constant or were not detected. The rate of PCE disappearance was 34 times faster in VOA vials at 55 degrees C compared to values obtained with flame-sealed ampules containing PCE-contaminated water. In addition, the concentration of TCE increased slightly in flame-sealed ampules incubated at 55 degrees C, while a decrease in TCE levels was observed in the VOA vials. The observed losses of PCE and TCE in the VOA vials were attributed to diffusion and sorption in the septa, rather than to dechlorination. These findings demonstrate that VOA vials are not suitable for measuring rates of volatile organic compound hydrolysis at elevated temperatures.

  20. Untargeted metabolomic analysis using liquid chromatography quadrupole time-of-flight mass spectrometry for non-volatile profiling of wines

    Energy Technology Data Exchange (ETDEWEB)

    Arbulu, M. [Department of Analytical Chemistry, Faculty of Pharmacy, University of the Basque Country, 01006 Vitoria-Gasteiz (Spain); Sampedro, M.C. [Central Service of Analysis, SGIker, University of the Basque Country, 01006 Vitoria-Gasteiz (Spain); Gómez-Caballero, A.; Goicolea, M.A. [Department of Analytical Chemistry, Faculty of Pharmacy, University of the Basque Country, 01006 Vitoria-Gasteiz (Spain); Barrio, R.J., E-mail: r.barrio@ehu.es [Department of Analytical Chemistry, Faculty of Pharmacy, University of the Basque Country, 01006 Vitoria-Gasteiz (Spain)

    2015-02-09

    Highlights: • An untargeted metabolomic method for the non-volatile profile of the Graciano wine was developed. • 411 different metabolites in Graciano Vitis vinifera red wine were identified. • 15 compounds could serve to differentiate Graciano and Tempranillo wines. • An enological database (WinMet) with 2080 compounds was constructed. - Abstract: The current study presents a method for comprehensive untargeted metabolomic fingerprinting of the non-volatile profile of the Graciano Vitis vinifera wine variety, using liquid chromatography/electrospray ionization time of flight mass spectrometry (LC–ESI-QTOF). Pre-treatment of samples, chromatographic columns, mobile phases, elution gradients and ionization sources, were evaluated for the extraction of the maximum number of metabolites in red wine. Putative compounds were extracted from the raw data using the extraction algorithm, molecular feature extractor (MFE). For the metabolite identification the WinMet database was designed based on electronic databases and literature research and includes only the putative metabolites reported to be present in oenological matrices. The results from WinMet were compared with those in the METLIN database to evaluate how much the databases overlap for performing identifications. The reproducibility of the analysis was assessed using manual processing following replicate injections of Vitis vinifera cv. Graciano wine spiked with external standards. In the present work, 411 different metabolites in Graciano Vitis vinifera red wine were identified, including primary wine metabolites such as sugars (4%), amino acids (23%), biogenic amines (4%), fatty acids (2%), and organic acids (32%) and secondary metabolites such as phenols (27%) and esters (8%). Significant differences between varieties Tempranillo and Graciano were related to the presence of fifteen specific compounds.

  1. Development and Application of a Fast Chromatography Technique for Analysis of Biogenic Volatile Organic Compounds in Plant Emissions

    Science.gov (United States)

    Jones, C. E.; Kato, S.; Nakashima, Y.; Yamazakii, S.; Kajii, Y. J.

    2011-12-01

    Biogenic volatile organic compounds (BVOCs) emitted from vegetation constitute the largest fraction (>90 %) of total global non-methane VOC supplied to the atmosphere, yet the chemical complexity of these emissions means that achieving comprehensive measurements of BVOCs, and in particular the less volatile terpenes, is not straightforward. As such, there is still significant uncertainty associated with the contribution of BVOCs to the tropospheric oxidation budget, and to atmospheric secondary organic aerosol (SOA) formation. The rate of BVOC emission from vegetation is regulated by environmental conditions such as light intensity and temperature, and thus can be highly variable, necessitating high time-resolution BVOC measurements. In addition, the numerous monoterpene and sesquiterpene isomers, which are indistinguishable by some analytical techniques, have greatly varying lifetimes with respect to atmospheric oxidants, and as such quantification of each individual isomer is fundamental to achieving a comprehensive characterisation of the impact of BVOCs upon the atmospheric oxidation capacity. However, established measurement techniques for these trace gases typically offer a trade-off between sample frequency and the level of speciation; detailed information regarding chemical composition may be obtained, but with reduced time resolution, or vice versa. We have developed a Fast-GC-FID technique for quantification of a range of monoterpene, sesquiterpene and oxygenated C10 BVOC isomers, which retains the separation capability of conventional gas chromatography, yet offers considerably improved sample frequency. Development of this system is ongoing, but currently a 20 m x 0.18 mm i.d resistively heated metal column is employed to achieve chromatographic separation of thirteen C10-C15 BVOCs, within a total cycle time of ~15 minutes. We present the instrument specifications and analytical capability, together with the first application of this Fast-GC technique

  2. Characterization of wood plastic composites made from landfill-derived plastic and sawdust: Volatile compounds and olfactometric analysis

    Energy Technology Data Exchange (ETDEWEB)

    Félix, Juliana S., E-mail: jfelix@unizar.es [Department of Analytical Chemistry, I3A, EINA, University of Zaragoza (UNIZAR), Zaragoza 50018 (Spain); Domeño, Celia, E-mail: cdomeno@unizar.es [Department of Analytical Chemistry, I3A, EINA, University of Zaragoza (UNIZAR), Zaragoza 50018 (Spain); Nerín, Cristina, E-mail: cnerin@unizar.es [Department of Analytical Chemistry, I3A, EINA, University of Zaragoza (UNIZAR), Zaragoza 50018 (Spain)

    2013-03-15

    Graphical abstract: This work details the characterization of VOCs of WPC, produced from residual materials which would have landfills as current destination, and evaluates their odor profile. Highlights: ► More than 140 volatile compounds were identified in raw materials and WPC products. ► Markers were related to the thermal degradation, sawdust or coupling agents. ► WPC prototype showed a characteristic odor profile of burnt, sweet and wax-like. ► Aldehydes, carboxylic acids, ketones and phenols were odor descriptors of WPC. - Abstract: Application of wood plastic composites (WPCs) obtained from recycled materials initially intended for landfill is usually limited by their composition, mainly focused on release of volatile organic compounds (VOCs) which could affect quality or human safety. The study of the VOCs released by a material is a requirement for new composite materials. Characterization and quantification of VOCs of several WPC produced with low density polyethylene (LDPE) and polyethylene/ethylene vinyl acetate (PE/EVA) films and sawdust were carried out, in each stage of production, by solid phase microextraction in headspace mode (HS-SPME) and gas chromatography–mass spectrometry (GC–MS). An odor profile was also obtained by HS-SPME and GC–MS coupled with olfactometry analysis. More than 140 compounds were observed in the raw materials and WPC samples. Some quantified compounds were considered WPC markers such as furfural, 2-methoxyphenol, N-methylphthalimide and 2,4-di-tert-butylphenol. Hexanoic acid, acetic acid, 2-methoxyphenol, acetylfuran, diacetyl, and aldehydes were the most important odorants. None of the VOCs were found to affect human safety for use of the WPC.

  3. A rapid method for the chromatographic analysis of volatile organic compounds in exhaled breath of tobacco cigarette and electronic cigarette smokers.

    Science.gov (United States)

    Marco, Esther; Grimalt, Joan O

    2015-09-04

    A method for the rapid analysis of volatile organic compounds (VOCs) in smoke from tobacco and electronic cigarettes and in exhaled breath of users of these smoking systems has been developed. Both disposable and rechargeable e-cigarettes were considered. Smoke or breath were collected in Bio-VOCs. VOCs were then desorbed in Tenax cartridges which were subsequently analyzed by thermal desorption coupled to gas chromatography-mass spectrometry. The method provides consistent results when comparing the VOC compositions from cigarette smoke and the equivalent exhaled breath of the smokers. The differences in composition of these two sample types are useful to ascertain which compounds are retained in the respiratory system after tobacco cigarette or e-cigarette smoking. Strong differences were observed in the VOC composition of tobacco cigarette smoke and exhaled breath when comparing with those of e-cigarette smoking. The former involved transfers of a much larger burden of organic compounds into smokers, including benzene, toluene, naphthalene and other pollutants of general concern. e-Cigarettes led to strong absorptions of propylene glycol and glycerin in the users of these systems. Tobacco cigarettes were also those showing highest concentration differences between nicotine concentrations in smoke and exhaled breath. The results from disposable e-cigarettes were very similar to those from rechargeable e-cigarettes. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. System of extraction of volatiles from soil using microwave processes

    Science.gov (United States)

    Ethridge, Edwin C. (Inventor); Kaukler, William F. (Inventor)

    2013-01-01

    A device for the extraction and collection of volatiles from soil or planetary regolith. The device utilizes core drilled holes to gain access to underlying volatiles below the surface. Microwave energy beamed into the holes penetrates through the soil or regolith to heat it, and thereby produces vapor by sublimation. The device confines and transports volatiles to a cold trap for collection.

  5. Pricing Volatility Referenced Assets

    Directory of Open Access Journals (Sweden)

    Alan De Genaro Dario

    2006-12-01

    Full Text Available Volatility swaps are contingent claims on future realized volatility. Variance swaps are similar instruments on future realized variance, the square of future realized volatility. Unlike a plain vanilla option, whose volatility exposure is contaminated by its asset price dependence, volatility and variance swaps provide a pure exposure to volatility alone. This article discusses the risk-neutral valuation of volatility and variance swaps based on the framework outlined in the Heston (1993 stochastic volatility model. Additionally, the Heston (1993 model is calibrated for foreign currency options traded at BMF and its parameters are used to price swaps on volatility and variance of the BRL / USD exchange rate.

  6. The analysis of volatile organic compounds in exhaled breath and biomarkers in exhaled breath condensate in children - clinical tools or scientific toys?

    Science.gov (United States)

    van Mastrigt, E; de Jongste, J C; Pijnenburg, M W

    2015-07-01

    Current monitoring strategies for respiratory diseases are mainly based on clinical features, lung function and imaging. As airway inflammation is the hallmark of many respiratory diseases in childhood, noninvasive methods to assess the presence and severity of airway inflammation might be helpful in both diagnosing and monitoring paediatric respiratory diseases. At present, the measurement of fractional exhaled nitric oxide is the only noninvasive method available to assess eosinophilic airway inflammation in clinical practice. We aimed to evaluate whether the analysis of volatile organic compounds (VOCs) in exhaled breath (EB) and biomarkers in exhaled breath condensate (EBC) is helpful in diagnosing and monitoring respiratory diseases in children. An extensive literature search was conducted in Medline, Embase and PubMed on the analysis and applications of VOCs in EB and EBC in children. We retrieved 1165 papers, of which nine contained original data on VOCs in EB and 84 on biomarkers in EBC. These were included in this review. We give an overview of the clinical applications in childhood and summarize the methodological issues. Several VOCs in EB and biomarkers in EBC have the potential to distinguish patients from healthy controls and to monitor treatment responses. Lack of standardization of collection methods and analysis techniques hampers the introduction in clinical practice. The measurement of metabolomic profiles may have important advantages over detecting single markers. There is a lack of longitudinal studies and external validation to reveal whether EB and EBC analysis have added value in the diagnostic process and follow-up of children with respiratory diseases. In conclusion, the use of VOCs in EB and biomarkers in EBC as markers of inflammatory airway diseases in children is still a research tool and not validated for clinical use.

  7. Enantioselective GC-MS analysis of volatile components from rosemary (Rosmarinus officinalis L.) essential oils and hydrosols.

    Science.gov (United States)

    Tomi, Kenichi; Kitao, Makiko; Konishi, Norihiro; Murakami, Hiroshi; Matsumura, Yasuki; Hayashi, Takahiro

    2016-05-01

    Essential oils and hydrosols were extracted from rosemary harvested in different seasons, and the chemical compositions of volatile components in the two fractions were analyzed by gas chromatography-mass spectrometry (GC-MS). Enantiomers of some volatile components were also analyzed by enantioselective GC-MS. Classification of aroma components based on chemical groups revealed that essential oils contained high levels of monoterpene hydrocarbons but hydrosols did not. Furthermore, the enantiomeric ratios within some volatile components were different from each other; for example, only the (S)-form was observed for limonene and the (R)-form was dominant for verbenone. These indicate the importance of determining the enantiomer composition of volatile components for investigating the physiological and psychological effects on humans. Overall, enantiomeric ratios were determined by volatile components, with no difference between essential oils and hydrosols or between seasons.

  8. Electronic nose and GC-MS analysis of volatile compounds in Tuber magnatum Pico: evaluation of different storage conditions.

    Science.gov (United States)

    Pennazza, G; Fanali, C; Santonico, M; Dugo, L; Cucchiarini, L; Dachà, M; D'Amico, A; Costa, R; Dugo, P; Mondello, L

    2013-01-15

    The characteristic aromatic composition of white truffles (Tuber magnatum Pico) determines its culinary and commercial value. However modifications of truffle organoleptic proprieties occur during preservation. A study of headspace of white truffles by using Electronic nose (E-nose), gas chromatography-mass spectrometry (GC-MS) and sensory analyses was performed. Truffles were stored at different conditions for 7 days: +4 and +8°C wrapped in blotting paper or covered by rice or none of the above. Headspace E-nose measurements and sensory analyses were performed each day. Statistical multivariate analysis of the data showed the capability of E-nose to predict sensorial analysis scores and to monitor aroma profile changes during storage. Truffle's volatile molecules were also extracted by headspace solid phase microextraction technique and separated and identified by GC-MS. Partial Components Analysis of data was performed. E-nose and GC-MS results were in agreement and showed that truffle storage in paper at +8°C seemed to be the best storage condition.

  9. Analysis of volatiles in porcine liver pâtés with added sage and rosemary essential oils by using SPME-GC-MS.

    Science.gov (United States)

    Estévez, Mario; Ventanas, Sonia; Ramírez, Rosario; Cava, Ramón

    2004-08-11

    The effect of the addition of two natural antioxidant extracts (sage and rosemary essential oils) and one synthetic (BHT) on the generation of volatile compounds in liver pâtés from Iberian and white pigs was analyzed using SPME-GC-MS. Lipid-derived volatiles such as aldehydes [hexanal, octanal, nonanal, hept-(Z)-4-enal, oct-(E)-2-enal, non-(Z)-2-enal, dec-(E)-2-enal, deca-(E,Z)-2,4-dienal] and alcohols (pentan-1-ol, hexan-1-ol, oct-1-en-3-ol) were the most abundant compounds in the headspace of porcine liver pâtés. Pâtés from different pig breeds presented different volatiles profiles due to their different oxidation susceptibilities as a probable result of their fatty acid profiles and vitamin E content. Regardless of the origin of the pâtés, the addition of BHT successfully reduced the amount of volatiles derived from PUFA oxidation. Added essential oils showed a different effect on the generation of volatiles whether they were added in pâtés from Iberian or white pigs because they inhibited lipid oxidation in the former and enhanced oxidative instability in the latter. SPME successfully allowed the isolation and analysis of 41 volatile terpenes from pâtés with added sage and rosemary essential oils including alpha-pinene, beta-myrcene, 1-limonene, (E)-caryophyllene, linalool, camphor, and 1,8-cineole, which might contribute to the aroma characteristics of liver pâtés.

  10. Comprehensive two-dimensional gas chromatography-mass spectrometry analysis of volatile constituents in Thai vetiver root oils obtained by using different extraction methods.

    Science.gov (United States)

    Pripdeevech, Patcharee; Wongpornchai, Sugunya; Marriott, Philip J

    2010-01-01

    Vetiver root oil is known as one of the finest fixatives used in perfumery. This highly complex oil contains more than 200 components, which are mainly sesquiterpene hydrocarbons and their oxygenated derivatives. Since conventional GC-MS has limitation in terms of separation efficiency, the comprehensive two-dimensional GC-MS (GC x GC-MS) was proposed in this study as an alternative technique for the analysis of vetiver oil constituents. To evaluate efficiency of the hyphenated GC x GC-MS technique in terms of separation power and sensitivity prior to identification and quantitation of the volatile constituents in a variety of vetiver root oil samples. METHODOLOGY. Dried roots of Vetiveria zizanioides were subjected to extraction using various conditions of four different methods; simultaneous steam distillation, supercritical fluid, microwave-assisted, and Soxhlet extraction. Volatile components in all vetiver root oil samples were separated and identified by GC-MS and GC x GC-MS. The relative contents of volatile constituents in each vetiver oil sample were calculated using the peak volume normalization method. Different techniques of extraction had diverse effects on yield, physical and chemical properties of the vetiver root oils obtained. Overall, 64 volatile constituents were identified by GC-MS. Among the 245 well-resolved individual components obtained by GC x GC-MS, the additional identification of 43 more volatiles was achieved. In comparison with GC-MS, GC x GC-MS showed greater ability to differentiate the quality of essential oils obtained from diverse extraction conditions in terms of their volatile compositions and contents.

  11. Transmission Electron Microscopy Analysis of Tarball Formation and Volatility from Biomass-burning Aerosol Particles during the 2013 BBOP Campaign

    Science.gov (United States)

    Buseck, P. R.; Adachi, K.; Chand, D.; Kleinman, L. I.; Sedlacek, A. J., III

    2014-12-01

    Tar balls, a subset of organic aerosol that is characterized by spherical shape and amorphous composition, are presumed to be brown-carbon (BrC) particles that contribute to light absorption in the atmosphere. Because of their distinctive shapes, compositions, and lack of crystallinity, tar balls are uniquely identifiable using transmission electron microscopy (TEM). Using samples collected during BBOP, we performed a detailed investigation of their compositions, formation processes, and occurrence. They primarily originated from wildfires and are most abundant in relatively aged plumes (>several hours from emission). Their features are similar to those from Mexico measured during the 2006 MILAGRO campaign, but their number fractions are more abundant in the Idaho, Oregon, and Washington samples of BBOP. In order to determine the TB robustness with respect to heating, an experiment was carried out on a TEM grid containing a mixture of organic particles, nanosphere soot, and TBs during which the sample temperature was ramped from ~30 to 650 ºC. The TEM results collected at 30 and 600 ºC, the latter representing the filament temperature used by the AMS, indicate that material of lower volatility is lost by 600 ºC. Although there was some loss of material during the 15-minute temperature ramp, TBs were still present at the higher temperature. These preliminary findings suggest that the efficiency of AMS detection of TBs may be significantly less than unity and potentially translate to an underreporting of the aerosol mass for wildfire plumes. If tar balls have low AMS detection efficiencies, an underestimate in organic aerosol mass will result.

  12. Integrated Data Collection Analysis (IDCA) Program — Ammonium Nitrate

    Energy Technology Data Exchange (ETDEWEB)

    Sandstrom, Mary M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Brown, Geoffrey W. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Preston, Daniel N. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Pollard, Colin J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Warner, Kirstin F. [Naval Surface Warfare Center (NSWC), Indian Head, MD (United States). Indian Head Division; Sorensen, Daniel N. [Naval Surface Warfare Center (NSWC), Indian Head, MD (United States). Indian Head Division; Remmers, Daniel L. [Naval Surface Warfare Center (NSWC), Indian Head, MD (United States). Indian Head Division; Phillips, Jason J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Shelley, Timothy J. [Bureau of Alcohol, Tobacco and Firearms, Redstone Arsenal, AL (United States); Reyes, Jose A. [Applied Research Associates, Tyndall AFB, FL (United States); Hsu, Peter C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Reynolds, John G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2013-05-17

    The Integrated Data Collection Analysis (IDCA) program is conducting a proficiency study for Small- Scale Safety and Thermal (SSST) testing of homemade explosives (HMEs). Described here are the results for impact, friction, electrostatic discharge, and differential scanning calorimetry analysis of ammonium nitrate (AN). AN was tested, in most cases, as both received from manufacturer and dried/sieved. The participants found the AN to be: 1) insensitive in Type 12A impact testing (although with a wide range of values), 2) completely insensitive in BAM friction testing, 3) less sensitive than the RDX standard in ABL friction testing, 4) less sensitive than RDX in ABL ESD testing, and 5) less sensitive than RDX and PETN in DSC thermal analyses.

  13. Novel Set-Up for Low-Disturbance Sampling of Volatile and Non-volatile Compounds from Plant Roots.

    Science.gov (United States)

    Eilers, Elisabeth J; Pauls, Gerhard; Rillig, Matthias C; Hansson, Bill S; Hilker, Monika; Reinecke, Andreas

    2015-03-01

    Most studies on rhizosphere chemicals are carried out in substrate-free set-ups or in artificial substrates using sampling methods that require an air flow and may thus cause disturbance to the rhizosphere. Our study aimed to develop a simplified and inexpensive system that allows analysis of rhizosphere chemicals at experimentally less disturbed conditions. We designed a mesocosm in which volatile rhizosphere chemicals were sampled passively (by diffusion) without air- and water flow on polydimethylsiloxane-(PDMS) tubes. Dandelion (Taraxacum sect. ruderalia) was used as model plant; roots were left undamaged. Fifteen volatiles were retrieved from the sorptive material by thermal desorption for analysis by gas chromatography/mass spectrometry (GC/MS). Furthermore, three sugars were collected from the rhizosphere substrate by aqueous extraction and derivatized prior to GC/MS analysis. In order to study how the quantity of detected rhizosphere compounds depends on the type of soil or substrate, we determined the matrix-dependent recovery of synthetic rhizosphere chemicals. Furthermore, we compared sorption of volatiles on PDMS tubes with and without direct contact to the substrate. The results show that the newly designed mesocosm is suitable for low-invasive extraction of volatile and non-volatile compounds from rhizospheres. We further highlight how strongly the type of substrate and contact of PDMS tubes to the substrate affect the detectability of compounds from rhizospheres.

  14. Experimental design applied to the analysis of volatile compounds in apple juice by headspace solid-phase microextraction.

    Science.gov (United States)

    Llorente, Daniel Díaz; Abrodo, Pilar Arias; de la Fuente, Enrique Dapena; Alvarez, Jaime González; Alvarez, Maria Dolores Gutiérrez; Gomis, Domingo Blanco

    2011-06-01

    A simple and fast method based on solid-phase microextraction (SPME) followed by fast gas chromatography (Fast GC) has been developed for the analysis of volatile compounds in Asturian apple juices employed in the cider production. Three different fiber coatings have been checked (PDMS, PDMS-DVB and CAR-PDMS) and PDMS-DVB has been presented to be the most suitable one. Experimental design has been employed in the optimization of extraction factors and robustness assessment. The use of Fast GC allowed the separation of 14 compounds (esters, aldehydes and alcohols) in approximately 4 min, clearly reducing the analysis time when compared to conventional GC. Good linearity, recoveries and repeatability of the solid-phase microextraction were obtained with r(2) values, recoveries and relative standard deviations ranging from 0.9822 to 0.9998, 83.2 to 109.8% and 0.5 to 11.7%, respectively, using standard solution. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. A new matrix assisted ionization method for the analysis of volatile and nonvolatile compounds by atmospheric probe mass spectrometry.

    Science.gov (United States)

    Chakrabarty, Shubhashis; Pagnotti, Vincent S; Inutan, Ellen D; Trimpin, Sarah; McEwen, Charles N

    2013-07-01

    Matrix assisted ionization of nonvolatile compounds is shown not to be limited to vacuum conditions and does not require a laser. Simply placing a solution of analyte dissolved with a suitable matrix such as 3-nitrobenzonitrile (3-NBN) or 2,5-dihydroxyacetophenone on a melting point tube and gently heating the dried sample near the ion entrance aperture of a mass spectrometer using a flow of gas produces abundant ions of peptides, small proteins, drugs, and polar lipids. Fundamental studies point to matrix-mediated ionization occurring prior to the entrance aperture of the mass spectrometer. The method is analytically useful, producing peptide mass fingerprints of bovine serum albumin tryptic digest consuming sub-picomoles of sample. Application of 100 fmol of angiotensin I in 3-NBN matrix produces the doubly and triply protonated molecular ions as the most abundant peaks in the mass spectrum. No carryover is observed for samples containing up to 100 pmol of this peptide. A commercial atmospheric samples analysis probe provides a simple method for sample introduction to an atmospheric pressure ion source for analysis of volatile and nonvolatile compounds without using the corona discharge but using sample preparation similar to matrix-assisted laser desorption/ionization.

  16. Development of a portable instrument for the continuous analysis of volatile organic compounds (VOCs) and its application to environmental monitoring.

    Science.gov (United States)

    Yamada, Etsu; Matsushita, Kazumasa; Nakamura, Mitsuaki; Fuse, Yasuro; Miki, Sadao; Fujimoto, Kiyoomi; Morita, Hiroyoshi; Shimada, Osamu

    2006-01-01

    A small, time efficient and sensitive instrument for the continuous analysis of very volatile organic compounds (VOCs) with a boiling point lower than 100 degrees C in addition to the analysis of VOCs with a boiling point in the range of 100-150 degrees C was developed and applied to the measurement of VOCs in the course of university research and environmental monitoring. VOCs, such as n-hexane, acetone, ethyl acetate, alcohols, benzene, toluene and xylene, were continuously measured once every 30 min. The detection limits of hexane, ethyl acetate, benzene and toluene at a preconcentration time of 10 min were 0.41 microg/m(3) (0.12 ppb), 0.67 microg/m(3) (0.19 ppb), 0.22 microg/m(3) (0.07 ppb) and 0.22 microg/m(3) (0.06 ppb), respectively. The relative standard deviations of VOCs were less than 5%. The sensitivities of the present method VOCs were higher than those of the conventional method. The temporal changes in VOC concentrations in several laboratories and at a plant for the disposal of organic liquid wastes were measured, and the behavior of VOCs was analyzed. All the VOC concentrations, except that of ethyl acetate, determined using the portable instrument were slightly lower than those determined using a passive sampler. The portable instrument developed in the course of this study can be used for the risk assessment and management of chemicals.

  17. Integrated Data Collection Analysis (IDCA) Program - KClO3/Dodecane Mixture

    Energy Technology Data Exchange (ETDEWEB)

    Sandstrom, Mary M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Brown, Geoffrey W. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Preston, Daniel N. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Pollard, Colin J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Warner, Kirstin F. [Naval Surface Warfare Center (NSWC), Indian Head, MD (United States). Indian Head Division; Sorenson, Daniel N. [Naval Surface Warfare Center (NSWC), Indian Head, MD (United States). Indian Head Division; Remmers, Daniel L. [Naval Surface Warfare Center (NSWC), Indian Head, MD (United States). Indian Head Division; Shelley, Timothy J. [Air Force Research Lab. (AFRL), Tyndall AFB, FL (United States); Whinnery, LeRoy L. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Hsu, Peter C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Reynolds, John G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2011-05-23

    The Integrated Data Collection Analysis (IDCA) program is conducting a proficiency study for Small-Scale Safety and Thermal (SSST) testing of homemade explosives (HMEs). Described here are the results for impact, friction, electrostatic discharge, and differential scanning calorimetry analysis of a mixture of KClO3 and dodecane—KClO3/dodecane mixture. This material was selected because of the challenge of performing SSST testing of a mixture of solid and liquid materials. The mixture was found to: 1) be more sensitive to impact than RDX, and PETN, 2) less sensitive to friction than PETN, and 3) less sensitive to spark than RDX. The thermal analysis showed little or no exothermic features suggesting that the dodecane volatilized at low temperatures. A prominent endothermic feature was observed assigned to melting of KClO3. This effort, funded by the Department of Homeland Security (DHS), ultimately will put the issues of safe handling of these materials in perspective with standard military explosives. The study is adding SSST testing results for a broad suite of different HMEs to the literature. Ultimately the study has the potential to suggest new guidelines and methods and possibly establish the SSST testing accuracies needed to develop safe handling practices for HMEs. Each participating testing laboratory uses identical test materials and preparation methods wherever possible. Note, however, the test procedures differ among the laboratories. The results are compared among the laboratories and then compared to historical data from various sources. The testing performers involved for the KClO3/dodecane mixture are Lawrence Livermore National Laboratory (LLNL), Los Alamos National Laboratory (LANL), and Indian Head Division, Naval Surface Warfare Center, (NSWC IHD). These tests are conducted as a proficiency study in order to establish some consistency in test protocols, procedures, and experiments and to understand

  18. Appendix C. Collection of Samples for Chemical Agent Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Koester, C; Thompson, C; Doerr, T; Scripsick, R

    2005-09-23

    This chapter describes procedures for the collection and analysis of samples of various matrices for the purpose of determining the presence of chemical agents in a civilian setting. This appendix is intended to provide the reader with sufficient information to make informed decisions about the sampling and analysis process and to suggest analytical strategies that might be implemented by the scientists performing sampling and analysis. This appendix is not intended to be used as a standard operating procedure to provide detailed instructions as to how trained scientists should handle samples. Chemical agents can be classified by their physical and chemical properties. Table 1 lists the chemical agents considered by this report. In selecting sampling and analysis methods, we have considered procedures proposed by the Organization for Prohibition of Chemical Weapons (OPCW), the U. S. Environmental Protection Agency (EPA), and peer-reviewed scientific literature. EPA analytical methods are good resources describing issues of quality assurance with respect to chain-of-custody, sample handling, and quality control requirements.

  19. Analysis of Volatile Fluids in Basalt: A Possible Source of Martian Methane

    Science.gov (United States)

    McMahon, S.; Parnell, J.; Blamey, N. J. F.

    2012-03-01

    Terrestrial basalts commonly yield methane when crushed into a sensitive mass spectrometer. Basalts are abundant on Mars, hence may be a source of martian methane, and should be targeted for analysis accordingly.

  20. Microwave distillation followed by headspace single drop microextraction coupled to gas chromatography-mass spectrometry (GC-MS) for fast analysis of volatile components of Echinophora platyloba DC.

    Science.gov (United States)

    Gholivand, Mohammad Bagher; Abolghasemi, Mir Mahdi; Piryaei, Marzieh; Maassoumi, Sayed Mohammad; Papzan, Abdolhamid

    2013-05-01

    To avoid the traditional and time consuming hydrodistillation, the analyses of volatile components in aerial parts of Echinophora platyloba DC was carried out by a simple microwave distillation followed by headspace single drop microextraction (MD-HS-SDME) coupled to gas chromatography-mass spectrometry (GC-MS). The headspace volatile compounds were collected after irradiation using a single drop of n-heptadecan. The extraction conditions were optimised using the relative peak areas as index. The chemical composition of the MD-HS-SDME extracts was confirmed according to their retention indexes and mass spectra. Fifty-three components were extracted and identified by using the MD-HS-SDME method. E-β-ocimene (53.81%), R-D-decalactone (12.75%), α-pinene (6.43%), n-heptanol (6.27%), β-phellanderne (2.70%) and linalool (1.89%) were the major constituents. Copyright © 2012 Elsevier Ltd. All rights reserved.

  1. Sovereign CDS Contagion in the European Union: A Multivariate GARCH-in-Variables Analysis of Volatility Spill-Overs

    OpenAIRE

    Oliveira, Maria Alberta; Santos, Carlos

    2014-01-01

    GARCH-with-variables model is used to assess volatility contagion in the Eurozone Debt Crisis. Credit Default Swaps on sovereign debt with 3 years maturity are used as a reference financial instrument, covering the sample period from 2008-2013. Daily data on Credit Default Swaps is used. We conclude that there is strong statistical evidence of volatility contagion in CDS spreads from the Eurozone periphery to its core. However, the direction of contagion is contingent on the periphery and cor...

  2. Time-varying volatility in Canadian and U.S. stock index and index futures markets: A multivariate analysis

    OpenAIRE

    Marie D. Racine; Lucy F. Ackert

    1998-01-01

    We use a multivariate generalized autoregressive heteroskedasticity model (M-GARCH) to examine three stock indexes and their associated futures prices: the New York Stock Exchange Composite, Standard and Poor's 500, and Toronto 35. The North American context is significant because markets in Canada and the United States share similar structures and regulatory environments. Our model allows examination of dependence in volatility as it captures time variation in volatility and cross-market inf...

  3. Solid phase microextraction-comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry for the analysis of honey volatiles.

    Science.gov (United States)

    Cajka, Tomás; Hajslová, Jana; Cochran, Jack; Holadová, Katerina; Klimánková, Eva

    2007-03-01

    Head-space solid phase microextration (SPME), followed by comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry (GCxGC-TOFMS), has been implemented for the analysis of honey volatiles, with emphasis on the optimal selection of SPME fibre and the first- and second-dimension GC capillaries. From seven SPME fibres investigated, a divinylbenzene/Carboxen/polydimethylsiloxane (DVB/CAR/PDMS) 50/30 microm fibre provided the best sorption capacity and the broadest range of volatiles extracted from the headspace of a mixed honey sample. A combination of DB-5ms x SUPELCOWAX 10 columns enabled the best resolution of sample components compared to the other two tested column configurations. Employing this powerful analytical strategy led to the identification of 164 volatile compounds present in a honey mixture during a 19-min GC run. Combination of this simple and inexpensive SPME-based sampling/concentration technique with the advanced separation/identification approach represented by GCxGC-TOFMS allows a rapid and comprehensive examination of the honey volatiles profile. In this way, the laboratory sample throughput can be increased significantly and, at the same time, the risk of erroneous identification, which cannot be avoided in one-dimensional GC separation, is minimised.

  4. Diagnostics of oral lichen planus based on analysis of volatile organic compounds in saliva

    Science.gov (United States)

    Kistenev, Yury; Borisov, Alexey; Shapovalov, Alexander; Baydik, Olga; Titarenko, Maria

    2017-03-01

    The ability of diagnostics of oral lichen planus (OLP) based on spectral analysis of saliva using the THz spectroscopy is presented. The study included 8 patients with clinically proven OLP. The comparison group consisted of 8 healthy volunteers. Absorption spectra of the saliva was measured using time-domain spectrometer T-spec (EXPLA) in the range 0.2-3THz and have been considered as the feature vectors of the state. The spatial distribution of the objects under study in the feature space was analyzed using principle component analysis. The groups under study were shown to separate in full. Thus, the saliva analysis by the THz spectroscopy technique can be potentially used as a method of noninvasive diagnostics of the OLP.

  5. Modeling and analysis of collective management of water resources

    Science.gov (United States)

    Tilmant, A.; van der Zaag, P.; Fortemps, P.

    2007-01-01

    Integrated Water Resources Management (IWRM) recommends, among other things, that the management of water resources systems be carried out at the lowest appropriate level in order to increase the transparency, acceptability and efficiency of the decision-making process. Empowering water users and stakeholders transforms the decision-making process by enlarging the number of point of views that must be considered as well as the set of rules through which decisions are taken. This paper investigates the impact of different group decision-making approaches on the operating policies of a water resource. To achieve this, the water resource allocation problem is formulated as an optimization problem which seeks to maximize the aggregated satisfaction of various water users corresponding to different approaches to collective choice, namely the utilitarian and the egalitarian ones. The optimal operating policies are then used in simulation and compared. The concepts are illustrated with a multipurpose reservoir in Chile. The analysis of simulation results reveals that if this reservoir were to be managed by its water users, both approaches to collective choice would yield significantly different operating policies. The paper concludes that the transfer of management to water users must be carefully implemented if a reasonable trade-off between equity and efficiency is to be achieved.

  6. Quantitative analysis of bloggers' collective behavior powered by emotions

    Science.gov (United States)

    Mitrović, Marija; Paltoglou, Georgios; Tadić, Bosiljka

    2011-02-01

    Large-scale data resulting from users' online interactions provide the ultimate source of information to study emergent social phenomena on the Web. From individual actions of users to observable collective behaviors, different mechanisms involving emotions expressed in the posted text play a role. Here we combine approaches of statistical physics with machine-learning methods of text analysis to study the emergence of emotional behavior among Web users. Mapping the high-resolution data from digg.com onto bipartite networks of users and their comments onto posted stories, we identify user communities centered around certain popular posts and determine emotional contents of the related comments by the emotion classifier developed for this type of text. Applied over different time periods, this framework reveals strong correlations between the excess of negative emotions and the evolution of communities. We observe avalanches of emotional comments exhibiting significant self-organized critical behavior and temporal correlations. To explore the robustness of these critical states, we design a network-automaton model on realistic network connections and several control parameters, which can be inferred from the dataset. Dissemination of emotions by a small fraction of very active users appears to critically tune the collective states.

  7. Modeling and analysis of collective management of water resources

    Directory of Open Access Journals (Sweden)

    A. Tilmant

    2006-09-01

    Full Text Available Integrated Water Resources Management (IWRM recommends, among other things, that the management of water resources systems be carried out at the lowest appropriate level in order to increase the transparency, acceptability and efficiency of the decision-making process. Empowering water users and stakeholders transforms the decision-making process by enlarging the number of point of views that must be considered as well as the set of rules through which decisions are taken. This paper investigates the impact of different group decision-making approaches on the operating policies of a water resource. To achieve this, the water resource allocation problem is formulated as an optimization problem which seeks to maximize the aggregated satisfaction of various water users corresponding to different approaches to collective choice, namely the utilitarian and the egalitarian ones. The optimal operating policies are then used in simulation and compared. The concepts are illustrated with a multipurpose reservoir in Chile. The analysis of simulation results reveals that if this reservoir were to be managed by its water users, both approaches to collective choice would yield significantly different operating policies. The paper concludes that the transfer of management to water users must be carefully implemented if a reasonable trade-off between equity and efficiency is to be achieved.

  8. A systematic review of breath analysis and detection of volatile organic compounds in COPD

    DEFF Research Database (Denmark)

    Christiansen, Anders; Davidsen, Jesper Rømhild; Titlestad, Ingrid;

    2016-01-01

    Chronic obstructive pulmonary disease (COPD) is, according to the WHO, the fifth leading cause of death worldwide, and is expected to increase to rank third in 2030. Few robust biomarkers for COPD exist, and several attempts have been made to find suitable molecular marker candidates. One rising...... research area is breath analysis, with several published attempts to find exhaled compounds as diagnostic markers. The field is broad and no review of published COPD breath analysis studies exists yet. We have conducted a systematic review examining the state of art and identified 12 suitable papers, which...

  9. Analysis of build-up of heavy metals and volatile organics on urban roads in gold coast, Australia.

    Science.gov (United States)

    Mahbub, Parvez; Goonetilleke, Ashantha; Ayoko, Godwin A; Egodawatta, Prasanna; Yigitcanlar, Tan

    2011-01-01

    Urban water quality can be significantly impaired by the build-up of pollutants such as heavy metals and volatile organics on urban road surfaces due to vehicular traffic. Any control strategy for the mitigation of traffic related build-up of heavy metals and volatile organic pollutants should be based on the knowledge of their build-up processes. In the study discussed in this paper, the outcomes of a detailed experimental investigation into build-up processes of heavy metals and volatile organics are presented. It was found that traffic parameters such as average daily traffic, volume over capacity ratio and surface texture depth had similar strong correlations with the build-up of heavy metals and volatile organics. Multicriteria decision analyses revealed that that the 1-74 microm particulate fraction of total suspended solids (TSS) could be regarded as a surrogate indicator for particulate heavy metals in build-up and this same fraction of total organic carbon could be regarded as a surrogate indicator for particulate volatile organics build-up. In terms of pollutants affinity, TSS was found to be the predominant parameter for particulate heavy metals build-up and total dissolved solids was found to be the predominant parameter for the potential dissolved particulate fraction in heavy metals buildup. It was also found that land use did not play a significant role in the build-up of traffic generated heavy metals and volatile organics.

  10. Impact of Thermal Decomposition on Thermal Desorption Instruments: Advantage of Thermogram Analysis for Quantifying Volatility Distributions of Organic Species.

    Science.gov (United States)

    Stark, Harald; Yatavelli, Reddy L N; Thompson, Samantha L; Kang, Hyungu; Krechmer, Jordan E; Kimmel, Joel R; Palm, Brett B; Hu, Weiwei; Hayes, Patrick L; Day, Douglas A; Campuzano-Jost, Pedro; Canagaratna, Manjula R; Jayne, John T; Worsnop, Douglas R; Jimenez, Jose L

    2017-08-01

    We present results from a high-resolution chemical ionization time-of-flight mass spectrometer (HRToF-CIMS), operated with two different thermal desorption inlets, designed to characterize the gas and aerosol composition. Data from two field campaigns at forested sites are shown. Particle volatility distributions are estimated using three different methods: thermograms, elemental formulas, and measured partitioning. Thermogram-based results are consistent with those from an aerosol mass spectrometer (AMS) with a thermal denuder, implying that thermal desorption is reproducible across very different experimental setups. Estimated volatilities from the detected elemental formulas are much higher than from thermograms since many of the detected species are thermal decomposition products rather than actual SOA molecules. We show that up to 65% of citric acid decomposes substantially in the FIGAERO-CIMS, with ∼20% of its mass detected as gas-phase CO2, CO, and H2O. Once thermal decomposition effects on the detected formulas are taken into account, formula-derived volatilities can be reconciled with the thermogram method. The volatility distribution estimated from partitioning measurements is very narrow, likely due to signal-to-noise limits in the measurements. Our findings indicate that many commonly used thermal desorption methods might lead to inaccurate results when estimating volatilities from observed ion formulas found in SOA. The volatility distributions from the thermogram method are likely the closest to the real distributions.

  11. Volatile N-nitrosamines in Environment Tobacco Smoke: Sampling,Analysis, Smission Factors, and Indoor Air Exposures

    Energy Technology Data Exchange (ETDEWEB)

    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.

  12. Utilization of micellar electrokinetic chromatography-tandem mass spectrometry employed volatile micellar phase in the analysis of cathinone designer drugs.

    Science.gov (United States)

    Švidrnoch, Martin; Lněníčková, Ludmila; Válka, Ivo; Ondra, Peter; Maier, Vítězslav

    2014-08-22

    A micellar electrokinetic chromatography method with tandem mass spectrometry has been developed for the selective separation, identification and determination of twelve new designer drugs from the group of synthetic cathinones. Ammonium salt of perfluorooctanoic acid at various concentrations as a volatile background electrolyte (BGE) to create micellar phase was studied for separation of selected synthetic cathinones with direct tandem mass spectrometry without significant loss of detection sensitivity. The optimized BGE contained 100 mM perfluorooctanoic acid with 200 mM ammonium hydroxide providing acceptable resolution of studied drugs in the MEKC step. In order to minimize interferences with matrix components and to preconcentrate target analytes, solid phase extraction was introduced as a clean-up step. The method was linear in the concentration range of 10-5000 ng mL(-1) and the limits of detection were in the range of 10-78 ng mL(-1). The method was demonstrated to be specific, sensitive, and reliable for the systematic toxicological analysis of these derivatives in urine samples.

  13. Screening of the key volatile organic compounds of Tuber melanosporum fermentation by aroma sensory evaluation combination with principle component analysis.

    Science.gov (United States)

    Liu, Rui-Sang; Jin, Guang-Huai; Xiao, Deng-Rong; Li, Hong-Mei; Bai, Feng-Wu; Tang, Ya-Jie

    2015-12-11

    Aroma results from the interplay of volatile organic compounds (VOCs) and the attributes of microbial-producing aromas are significantly affected by fermentation conditions. Among the VOCs, only a few of them contribute to aroma. Thus, screening and identification of the key VOCs is critical for microbial-producing aroma. The traditional method is based on gas chromatography-olfactometry (GC-O), which is time-consuming and laborious. Considering the Tuber melanosporum fermentation system as an example, a new method to screen and identify the key VOCs by combining the aroma evaluation method with principle component analysis (PCA) was developed in this work. First, an aroma sensory evaluation method was developed to screen 34 potential favorite aroma samples from 504 fermentation samples. Second, PCA was employed to screen nine common key VOCs from these 34 samples. Third, seven key VOCs were identified by the traditional method. Finally, all of the seven key VOCs identified by the traditional method were also identified, along with four others, by the new strategy. These results indicate the reliability of the new method and demonstrate it to be a viable alternative to the traditional method.

  14. Analysis of volatile organic compounds emitted from aircraft carpets:comparison using headspace and dynamic chamber tests 

    Institute of Scientific and Technical Information of China (English)

    WANG Chao; YANG Xu-Dong; GAO Peng

    2014-01-01

    Volatile organic compounds (VOCs) emitted from three types of carpets used in aircrafts were compared by using headspace and dynamic chamber tests. The headspace samples contained many compounds that were not detected in the dynamic chamber test;in addition, the dominant VOCs found by these two methods were different. The findings indicate that for highly sorptive materials such as carpets, headspace analysis may give inaccurate indication of actual VOC emissions, and it is necessary to conduct dynamic chamber tests over a certain period of time in order to identify the true emission characteristics. From the dynamic chamber tests, 2-ethyl-1-hexanol was the main VOC emitted from all three carpets. The study also examined the emission characteristics of aircraft carpets. In all experiments, total VOC (TVOC) concentration peaked within a few hours after the start of the experiment and was followed by rapid decay. The emission parameters of TVOC emitted by all three carpets were calculated and the simulated data matched the measured data well.

  15. Abundances of Volatile - Bearing Species from Evolved Gas Analysis of Samples from the Rocknest Aeolian Bedform in Gale Crater

    Science.gov (United States)

    Archer, P. D., Jr.; Franc, H. B.; Sutter, B.; McAdam, A.; Ming, D. W.; Morris, R. V.; Mahaffy, P. R.

    2013-01-01

    The Sample Analysis at Mars (SAM) instrument suite on board the Mars Science Laboratory (MSL) recently ran four samples from an aeolian bedform named Rocknest. SAM detected the evolution of H2O, CO2, O2, and SO2, indicative of the presence of multiple volatile bearing species (Fig 1). The Rocknest bedform is a windblown deposit selected as representative of both the windblown material in Gale crater as well as the globally-distributed martian dust. Four samples of Rocknest material were analyzed by SAM, all from the fifth scoop taken at this location. The material delivered to SAM passed through a 150 m sieve and is assumed to have been well mixed during the sample acquisition/preparation/handoff process. SAM heated the Rocknest samples to approx.835 C at a ramp rate of 35 C/min with a He carrier gas flow rate of apprx.1.5 standard cubic centimeters per minute and at an oven pressure of 30 mbar [1]. Evolved gases were detected by a quadrupole mass spectrometer (QMS). This abstract presents the molar abundances of H2O, CO2, O2, and SO2 as well as their concentration in rocknest samples using an estimated sample mass.

  16. Simulation Analysis of Sludge Disposal and Volatile Fatty Acids Production from Gravity Pressure Reactor via Wet Air Oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Park, Gwon Woo [Biomass and Waste Energy Laboratory, KIER, Daejeon (Korea, Republic of); Seo, Tae Wan; Lee, Hong-Cheol; Hwang, In-Ju [Environmental and Plant Engineering Research Institute, KICT, Goyang (Korea, Republic of)

    2016-04-15

    Efficacious wastewater treatment is essential for increasing sewage sludge volume and implementing strict environmental regulations. The operation cost of sludge treatment amounts up to 50% of the total costs for wastewater treatment plants, therefore, an economical sludge destruction method is crucially needed. Amid several destruction methods, wet air oxidation (WAO) can efficiently treat wastewater containing organic pollutants. It can be used not only for sludge destruction but also for useful by-product production. Volatile fatty acids (VFAs), one of many byproducts, is considered to be an important precursor of biofuel and chemical materials. Its high reaction condition has instituted the study of gravity pressure reactor (GPR) for an economical process of WAO to reduce operation cost. Simulation of subcritical condition was conducted using Aspen Plus with predictive Soave-Redlich-Kwong (PSRK) equation of state. Conjointly, simulation analysis for GPR depth, oxidizer type, sludge flow rate and oxidizer injection position was carried out. At GPR depth of 1000m and flow rate of 2 ton/h, the conversion and yield of VFAs were 92.02% and 0.17g/g, respectively.

  17. Solid phase micro-extraction GC-MS analysis of natural volatile components in melon and rice.

    Science.gov (United States)

    Verhoeven, Harrie A; Jonker, Harry; De Vos, Ric C H; Hall, Robert D

    2012-01-01

    The natural fragrance compounds produced by plants play key roles in the long-term fitness and survival of these plants as well as being of direct/indirect benefit to man. Almost all plant fragrances, either pleasant or unpleasant, comprise many different compounds, from different chemical classes and can indeed be highly complex in composition involving several hundred types of volatile molecule. Analyzing these mixtures and identifying their main (bio)active components is of importance in both fundamental and applied science. Gas Chromatography-Mass Spectrometry (GC-MS) plays a central role here. GC-MS has regularly been used for fragrance analysis and different extraction/adsorption and detection protocols have been designed specifically for plant materials. In this chapter, two methods are presented for two highly contrasting plant organs-a melon fruit and rice grains. Metabolomics analyses of these important food crops are already helping us understand better which components are most important in determining the flavour of these important food crops and how we might go about producing new "designer" crops which are even tastier than the existing ones.

  18. Characterization of wood plastic composites made from landfill-derived plastic and sawdust: volatile compounds and olfactometric analysis.

    Science.gov (United States)

    Félix, Juliana S; Domeño, Celia; Nerín, Cristina

    2013-03-01

    Application of wood plastic composites (WPCs) obtained from recycled materials initially intended for landfill is usually limited by their composition, mainly focused on release of volatile organic compounds (VOCs) which could affect quality or human safety. The study of the VOCs released by a material is a requirement for new composite materials. Characterization and quantification of VOCs of several WPC produced with low density polyethylene (LDPE) and polyethylene/ethylene vinyl acetate (PE/EVA) films and sawdust were carried out, in each stage of production, by solid phase microextraction in headspace mode (HS-SPME) and gas chromatography-mass spectrometry (GC-MS). An odor profile was also obtained by HS-SPME and GC-MS coupled with olfactometry analysis. More than 140 compounds were observed in the raw materials and WPC samples. Some quantified compounds were considered WPC markers such as furfural, 2-methoxyphenol, N-methylphthalimide and 2,4-di-tert-butylphenol. Hexanoic acid, acetic acid, 2-methoxyphenol, acetylfuran, diacetyl, and aldehydes were the most important odorants. None of the VOCs were found to affect human safety for use of the WPC.

  19. Collection, Analysis, and Monitoring of Social Media Content

    DEFF Research Database (Denmark)

    Lashari, Intzar Ali

    developed measure to quantify from the data based on sentiment analysis and network relation. The proposed methods have been implemented as software tools to provide features for the collection, monitoring, and processing of social media content. In this thesis, our focus was on You-Tube and twitter......Social network sites are currently booming with their popularity and usage of the users all around the globe. There are so many on-line networking sites which currently allowing all users to create their respective profile and creating a connection with their own involvement and preparing their own...... preferred network so that they can participate in their exciting information. The data they exchange that could be based on opinion, observation, or comment on already posted material or they might upload their photo, videos and etc. The exciting perspective of the users on the social network...

  20. Quantitative Analysis of Bloggers Collective Behavior Powered by Emotions

    CERN Document Server

    Mitrović, Marija; Tadić, Bosiljka

    2010-01-01

    Large-scale data resulting from users online interactions provide the ultimate source of information to study emergent social phenomena on the Web. From individual actions of users to observable collective behaviors, different mechanisms involving emotions expressed in the posted text play a role. Here we combine approaches of statistical physics with machine-learning methods of text analysis to study emergence of the emotional behavior among Web users. Mapping the high-resolution data from digg.com onto bipartite network of users and their comments onto posted stories, we identify user communities centered around certain popular posts and determine emotional contents of the related comments by the emotion-classifier developed for this type of texts. Applied over different time periods, this framework reveals strong correlations between the excess of negative emotions and the evolution of communities. We observe avalanches of emotional comments exhibiting significant self-organized critical behavior and tempo...

  1. Respuesta de Anopheles albimanus a compuestos volátiles de casas del sur de Chiapas, México Behavioral response of Anopheles albimanus to volatile compounds collected inside houses from the south of Chiapas, Mexico

    Directory of Open Access Journals (Sweden)

    Silvany Mayoly Ríos-Delgado

    2008-10-01

    Full Text Available OBJETIVO: Determinar el efecto de los compuestos volátiles en las casas sobre la respuesta conductual del vector del paludismo Anopheles albimanus. MATERIAL Y MÉTODOS: El estudio se realizó en enero de 2006 en el ejido Nueva Independencia, municipio de Suchiate, Chiapas. Se colectaron compuestos volátiles dentro de casas y los extractos se probaron sobre hembras sin alimentar en un olfatómetro en "Y". Los extractos se analizaron mediante cromatografía de gases-espectrometría de masas (CG-EM. RESULTADOS: Se obtuvieron 28 extractos, 12 presentaron respuesta de atracción y dos de repelencia. Los análisis por CG-EM indicaron variación en la presencia de compuestos volátiles y no se vincularon con compuestos específicos indicativos de algún efecto. CONCLUSIONES: Los volátiles en casas presentaron efecto de atracción y repelencia para An. albimanus. No se reconoció un patrón definido en cuanto a la presencia de compuestos químicos característicos y la respuesta obtenida.OBJECTIVE: To determine effects of volatile compounds in homes on the behavioral response of Anopheles albimanus. MATERIAL AND METHODS: The study was conducted in January 2006, in the village of Nueva Independencia village, Suchiate, Chiapas. Volatile compounds were collected inside homes and the extracts were tested on unfed females in a Y-olfactometer. Extracts were analyzed in a gas chromatography-mass spectrometry system (GC-MS. RESULTS: Twenty eight extracts were obtained, twelve presented attraction and two repellency responses. GC-MS analyses of the extracts indicated variation in the volatile compound present in the extracts, but could not associated specific compounds with any particular effect. CONCLUSIONS: Within homes, volatiles presented attraction and repellency responses to An. albimanus. A definate pattern concerning the presence of a characteristic chemical compound and the observed response was not found.

  2. Distribution characteristics of volatile methylsiloxanes in Tokyo Bay watershed in Japan: Analysis of surface waters by purge and trap method.

    Science.gov (United States)

    Horii, Yuichi; Minomo, Kotaro; Ohtsuka, Nobutoshi; Motegi, Mamoru; Nojiri, Kiyoshi; Kannan, Kurunthachalam

    2017-05-15

    Surface waters including river water and effluent from sewage treatment plants (STPs) were collected from Tokyo Bay watershed, Japan, and analyzed for seven cyclic and linear volatile methylsiloxanes (VMSs), i.e., D3, D4, D5, D6, L3, L4, and L5 by an optimized purge and trap extraction method. The total concentrations of seven VMSs (ΣVMS) in river water ranged from <4.9 to 1700ng/L (mean: 220ng/L). The individual mean concentrations of cyclic VMSs in surface waters were; 10ng/L for D3, 13ng/L for D4, 180ng/L for D5, and 18ng/L for D6. The concentrations of ΣVMS determined in STP effluents varied widely from 99 to 2500ng/L and the individual mean concentrations were 21ng/L for D3, 27ng/L for D4, 540ng/L for D5, and 45ng/L for D6. D5, which is widely used in personal-care products, was found to be the most abundant compound in both river water and STP effluent. Linear VMSs were detected at much lower frequency and concentrations than those of cyclic VMSs. The measured concentrations of D4 were below the no-observed effect concentration (NOEC). The annual emission of ΣVMS through STPs into Tokyo Bay watershed was estimated at 2300kg. Our results indicate widespread distribution of VMSs in Tokyo Bay watershed and the influence of domestic wastewater discharges as a source of VMSs in the aquatic environment.

  3. The 1930 Irpinia earthquake: collection and analysis of historical waveforms

    Science.gov (United States)

    Ferrari, G.; Megna, A.; Nardi, A.; Palombo, B.; Perniola, B.; Pino, N.

    2002-12-01

    The 1930 Irpinia earthquake is one of the most destructive events recorded by instruments in Italy. Several large events occurred in the same area before (1456, 1694, 1702, 1732, 1910) and after (1962, 1980, 1983) 1930. It has been hypothesized that significant differences characterized the source geometry. Early work carried out by several authors on macroseismic studies and a single-station waveform analysis, suggests a quasi-strike slip mechanism on an approximately EW-oriented fault plain. Conversely, all the major events in the area display normal fault mechanisms on Apennine-oriented (NW-SE) fault planes. In the present work we have collected about 45 waveforms for the 1930 earthquake, recorded in various European observatories, aiming to find precious hints on source geometry and kinematics. The seismograms have been rasterized, digitized and processed within the framework of the SISMOS project. The study of this earthquake is part of a wider ongoing research program on the 20th century Irpinia earthquakes (1910, 1030, 1962 and 1980) within the collaboration between the TROMOS and SISMOS projects of the National Institute of Geophysics and Volcanology. The search and recovery of the historical recordings is a unique opportunity to shed light upon scientific aspects related to this kind of investigation. Preliminary results about the 1930 earthquake waveform analysis are presented here.

  4. Integrated Data Collection Analysis (IDCA) Program - SSST Testing Methods

    Energy Technology Data Exchange (ETDEWEB)

    Sandstrom, Mary M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Brown, Geoffrey W. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Preston, Daniel N. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Pollard, Colin J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Warner, Kirstin F. [Naval Surface Warfare Center (NSWC), Indian Head, MD (United States). Indian Head Division; Remmers, Daniel L. [Naval Surface Warfare Center (NSWC), Indian Head, MD (United States). Indian Head Division; Sorensen, Daniel N. [Naval Surface Warfare Center (NSWC), Indian Head, MD (United States). Indian Head Division; Whinnery, LeRoy L. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Phillips, Jason J. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Shelley, Timothy J. [Bureau of Alcohol, Tobacco and Firearms (ATF), Huntsville, AL (United States); Reyes, Jose A. [Applied Research Associates, Tyndall AFB, FL (United States); Hsu, Peter C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Reynolds, John G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2013-03-25

    The Integrated Data Collection Analysis (IDCA) program is conducting a proficiency study for Small- Scale Safety and Thermal (SSST) testing of homemade explosives (HMEs). Described here are the methods used for impact, friction, electrostatic discharge, and differential scanning calorimetry analysis during the IDCA program. These methods changed throughout the Proficiency Test and the reasons for these changes are documented in this report. The most significant modifications in standard testing methods are: 1) including one specified sandpaper in impact testing among all the participants, 2) diversifying liquid test methods for selected participants, and 3) including sealed sample holders for thermal testing by at least one participant. This effort, funded by the Department of Homeland Security (DHS), is putting the issues of safe handling of these materials in perspective with standard military explosives. The study is adding SSST testing results for a broad suite of different HMEs to the literature. Ultimately the study will suggest new guidelines and methods and possibly establish the SSST testing accuracies needed to develop safe handling practices for HMEs. Each participating testing laboratory uses identical test materials and preparation methods wherever possible. The testing performers involved are Lawrence Livermore National Laboratory (LLNL), Los Alamos National Laboratory (LANL), Indian Head Division, Naval Surface Warfare Center, (NSWC IHD), Sandia National Laboratories (SNL), and Air Force Research Laboratory (AFRL/RXQL). These tests are conducted as a proficiency study in order to establish some consistency in test protocols, procedures, and experiments and to compare results when these testing variables cannot be made consistent.

  5. Continuous analysis of dissolved gaseous mercury and mercury volatilization in the upper St. Lawrence River: exploring temporal relationships and UV attenuation.

    Science.gov (United States)

    O'Driscoll, N J; Poissant, L; Canário, L; Ridal, J; Lean, D R S

    2007-08-01

    The formation and volatilization of dissolved gaseous mercury (DGM) is an important mechanism by which freshwaters may naturally reduce their mercury burden. Continuous analysis of surface water for diurnal trends in DGM concentration (ranging from 0 to 60.4 pg L(-1); n=613), mercury volatilization (ranging from 0.2 to 1.1 ng m(-2) h(-1); n=584), and a suite of physical and chemical measurements were performed during a 68 h period in the St. Lawrence River near Cornwall (Ontario, Canada) to examine the temporal relationships governing mercury volatilization. No lag-time was observed between net radiation and OGM concentrations (highest cross-correlation of 0.817), thus supporting previous research indicating faster photoreduction kinetics in rivers as compared to lakes. A significant lag-time (55-145 min; maximum correlation = 0.625) was observed between DGM formation and mercury volatilization, which is similar to surface water Eddy diffusion times of 42-132 min previously measured in the St. Lawrence River. A depth-integrated DGM model was developed using the diffuse integrated vertical attenuation coefficients for UVA and UVB (K(dI UVA) = 1.45 m(-1) K(dI UVB)= 3.20 m(-1)) Low attenuation of solar radiation was attributed to low concentrations of dissolved organic carbon (mean = 2.58 mg L(-1) and particulate organic carbon (mean = 0.58 mg L(-1) in the St. Lawrence River. The depth-integrated DGM model developed found that the top 0.3 m of the water column accounted for only 26% of the total depth-integrated DGM. A comparison with volatilization data indicated that a large portion (76% or 10.5 ng m(-2) of the maximum depth-integrated DGM (13.8 ng m(-2))is volatilized over a 24 h period. Therefore, at least 50% of all DGM volatilized was produced at depths below 0.3 m. These results highlight the importance of solar attenuation in regulating DGM formation with depth. The results also demonstrate both the fast formation of DGM in rivers and the importance of

  6. MetricForensics: A Multi-Level Approach for Mining Volatile Graphs

    Energy Technology Data Exchange (ETDEWEB)

    Henderson, Keith [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Eliassi-Rad, Tina [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Faloutsos, Christos [Carnegie Mellon Univ., Pittsburgh, PA (United States); Akoglu, Leman [Carnegie Mellon Univ., Pittsburgh, PA (United States); Li, Lei [Carnegie Mellon Univ., Pittsburgh, PA (United States); Maruhashi, Koji [Fujitsu Laboratories Ltd., Kanagawa (Japan); Prakash, B. Aditya [Carnegie Mellon Univ., Pittsburgh, PA (United States); Tong, H [Carnegie Mellon Univ., Pittsburgh, PA (United States)

    2010-02-08

    Advances in data collection and storage capacity have made it increasingly possible to collect highly volatile graph data for analysis. Existing graph analysis techniques are not appropriate for such data, especially in cases where streaming or near-real-time results are required. An example that has drawn significant research interest is the cyber-security domain, where internet communication traces are collected and real-time discovery of events, behaviors, patterns and anomalies is desired. We propose MetricForensics, a scalable framework for analysis of volatile graphs. MetricForensics combines a multi-level “drill down" approach, a collection of user-selected graph metrics and a collection of analysis techniques. At each successive level, more sophisticated metrics are computed and the graph is viewed at a finer temporal resolution. In this way, MetricForensics scales to highly volatile graphs by only allocating resources for computationally expensive analysis when an interesting event is discovered at a coarser resolution first. We test MetricForensics on three real-world graphs: an enterprise IP trace, a trace of legitimate and malicious network traffic from a research institution, and the MIT Reality Mining proximity sensor data. Our largest graph has »3M vertices and »32M edges, spanning 4:5 days. The results demonstrate the scalability and capability of MetricForensics in analyzing volatile graphs; and highlight four novel phenomena in such graphs: elbows, broken correlations, prolonged spikes, and strange stars.

  7. In Situ Analysis of the Volatiles in the Lunar Regolith with the Gas Analytical Package Experiment: Calibration of a GCMS Protoype

    Science.gov (United States)

    Coscia, David; Szopa, Cyril; Gerasimov, Mikhail; Wurz, Peter; Hofer, Lukas; cabane, Michel; Coll, Patrice; Buch, Arnaud; Fausch, Rico; Sap gir, S. A.; Aseev, Sergei; Zaitsev, Maxim; GAC Team

    2016-10-01

    Volatiles were recently shown to be present at the Lunar pole. They probably come from meteorites and micrometeorites which continuously deliver their material at the surface of the satellite. Thus, their characterisation would enable to better constrain the nature of the species brought by the meteorites to the solar system bodies, evaluate their evolution under Moon surface conditions. Within a few years, it could be done in situ with the Gas Analytical Package experiment onboard the Russian Luna Ressource mission, in part devoted to analyse regolith samples. With this aim, our team proposes an instrumentation to characterize in situ the content of volatiles in the lunar soil and rocks. This instrumentation would provide important reference data about the samples collected. It is based on pyrolysis coupled with gas chromatography and mass spectrometry, and could have the capability to: extract volatile materials (either condensed or present in the minerals) from the solid samples, separate the volatile and analyze their structure for identification and quantification, and analyze isotopic ratios in a certain extent. This instrumentation is based on an inheritance of the GAP instrument that was present onboard the late Phobos-Grunt probe. The instrumentation would be composed of : i. a pyrolyzer capable to heat the samples up to about 1000°C, and developed by IKI (Rus), which is also in charge to the whole instrument (PI M. Gerasimov); ii. a gas chromatograph devoted to separate and detect the volatile species released from the samples, developed by LATMOS and LISA (Fr.) ; iii. a time of flight mass spectrometer for the structural identification of the molecules, developed by the University of Bern (Sw.). This instrumentation should allow the identification of inorganic volatile molecules and small organic molecules (up to about benzene). This communication aims at presenting this instrumentation that should be onboard the Luna Ressource probe to the lunar South

  8. 肉苁蓉花序挥发物的GC-MS成分分析%Analysis of Volatile Compounds of Inflorescence by GC-MS from Cistanche deserticola

    Institute of Scientific and Technical Information of China (English)

    乔海莉; 陆鹏飞; 徐荣; 陈君; 王霞; 马维思; 刘同宁

    2012-01-01

    Objective:To study the volatile compounds from inflorescence of Cistanche deserticola and provide basis for its utilization and seed breeding. Methods:The volatile compounds were collected by dynamic headspace adsorption and analyzed by gas chroma-tography-mass spectrometry (GC-MS). Results: Forty volatile components were identified in inflorescence of Cistanche deserticola from squaring period to full-bloom period. The main components in buds of Cistanche deserticola were hydrocarbons and green leaf volatiles in squaring period. Some components were characteristic in buds and disappeared or decreased in flowers. The relative contents of some components gradually increased with the buds blooming. And some components only emerged in flowers of Cistanche deserticola. The higher content of esters and aromatics were found in flowers, which were significantly increased in comparison with the volatile compounds from buds. Conclusion: The volatile compounds from inflorescence of Cistanche deserticola were complex, consisting of various compositions and significantly different with buds blooming.%目的:研究肉苁蓉花序挥发物的种类和相对含量,为其综合利用和种子繁育提供依据.方法:利用动态顶空套袋吸附法和气相色谱-质谱联用分析方法,研究近自然状态下肉苁蓉花期花序挥发物成分.结果:现蕾期到盛花期共从肉苁蓉花序中鉴定出40种挥发性化合物.现蕾期主要为烃类与绿叶挥发物,随着肉苁蓉花序上花朵开放,部分挥发物相对含量消失或减少,部分化合物相对含量增加,并出现一些新化合物.初花期和盛花期肉苁蓉花序主要挥发性成分为芳香性酯类与苯环类化合物,其相对含量较现蕾期显著增加.结论:肉苁蓉花序的挥发性成分种类多,且随开花进程出现种类和相对含量的变化,构成了肉苁蓉不同花期的香韵.

  9. Quantitative analysis of volatile organic compounds using ion mobility spectra and cascade correlation neural networks

    Science.gov (United States)

    Harrington, Peter DEB.; Zheng, Peng

    1995-01-01

    Ion Mobility Spectrometry (IMS) is a powerful technique for trace organic analysis in the gas phase. Quantitative measurements are difficult, because IMS has a limited linear range. Factors that may affect the instrument response are pressure, temperature, and humidity. Nonlinear calibration methods, such as neural networks, may be ideally suited for IMS. Neural networks have the capability of modeling complex systems. Many neural networks suffer from long training times and overfitting. Cascade correlation neural networks train at very fast rates. They also build their own topology, that is a number of layers and number of units in each layer. By controlling the decay parameter in training neural networks, reproducible and general models may be obtained.

  10. 76 FR 37371 - Agency Information Collection: Comment Request for National Gap Analysis Program Evaluation

    Science.gov (United States)

    2011-06-27

    ... (ICR) for a new collection of information: National Gap Analysis Program Evaluation. This notice....S. Geological Survey Agency Information Collection: Comment Request for National Gap Analysis Program Evaluation AGENCY: United States Geological Survey (USGS), Interior. ACTION: Notice of a...

  11. An Empirical Analysis Of Stock Returns And Volatility: The Case Of Stock Markets From Central And Eastern Europe

    Directory of Open Access Journals (Sweden)

    Okičić Jasmina

    2015-04-01

    Full Text Available The main goal of this paper is to investigate the behaviour of stock returns in the case of stock markets from Central and Eastern Europe (CEE, focusing on the relationship between returns and conditional volatility. Since there is relatively little empirical research on the volatility of stock returns in underdeveloped stock markets, with even fewer studies on markets in the transitional economies of the CEE region, this paper is designed to shed some light on the econometric modelling of the conditional mean and volatility of stock returns from this region. The results presented in this paper provide confirmatory evidence that ARIMA and GARCH processes provide parsimonious approximations of mean and volatility dynamics in the case of the selected stock markets. There is overwhelming evidence corroborating the existence of a leverage effect, meaning that negative shocks increase volatility more than positive shocks do. Since financial decisions are generally based upon the trade-off between risk and return, the results presented in this paper will provide valuable information in decision making for those who are planning to invest in stock markets from the CEE region.

  12. An empirical analysis of freight rate and vessel price volatility transmission in global dry bulk shipping market

    Directory of Open Access Journals (Sweden)

    Lei Dai

    2015-10-01

    Full Text Available Global dry bulk shipping market is an important element of global economy and trade. Since newbuilding and secondhand vessels are often traded as assets and the freight rate is the key determinant of vessel price, it is important for shipping market participants to understand the market dynamics and price transmission mechanism over time to make suitable strategic decisions. To address this issue, a multi-variate GARCH model was applied in this paper to explore the volatility spillover effects across the vessel markets (including newbuilding and secondhand vessel markets and freight market. Specifically, the BEKK parameterization of the multi-variate GARCH model (BEKK GARCH was proposed to capture the volatility transmission effect from the freight market, newbuilding and secondhand vessel markets in the global dry bulk shipping industry. Empirical results reveal that significant volatility transmission effects exist in each market sector, i.e. capesize, panamax, handymax and handysize. Besides, the market volatility transmission mechanism varies among different vessel types. Moreover, some bilateral effects are found in the dry bulk shipping market, showing that lagged variances could affect the current variance in a counterpart market, regardless of the volatility transmission. A simple ratio is proposed to guide investors optimizing their portfolio allocations. The findings in this paper could provide unique insights for investors to understand the market and hedge their portfolios well.

  13. Development of a parallel sampling and analysis method for the elucidation of gas/particle partitioning of oxygenated semi-volatile organics: a limonene ozonolysis study

    Directory of Open Access Journals (Sweden)

    S. Rossignol

    2012-06-01

    Full Text Available The gas/particle partitioning behaviour of the semi-volatile fraction of secondary organic matter and the associated multiphase chemistry are key features to accurately evaluate climate and health impacts of secondary organic aerosol (SOA. However, today, the partitioning of oxygenated secondary species is rarely assessed in experimental SOA studies and SOA modelling is still largely based on estimated partitioning data. This paper describes a new analytical approach, solvent-free and easy to use, to explore the chemical composition of the secondary organic matter at a molecular scale in both gas and particulate phases. The method is based on thermal desorption (TD of gas and particulate samples, coupled with gas chromatography (GC and mass spectrometry (MS, with derivatisation on sampling supports. Gaseous compounds were trapped on Tenax TA adsorbent tubes pre-coated with pentafluorobenzylhydroxylamine (PFBHA or N-Methyl-N-(t-butyldimethylsilyltrifluoroacetamide (MTBSTFA. Particulate samples were collected onto quartz or Teflon-quartz filters and subsequently subjected to derivatisation with PFBHA or MTBSTFA before TD-GC/MS analysis. Method development and validation are presented for an atmospherically relevant range of organic acids and carbonyl and hydroxyl compounds. Application of the method to a limonene ozonolysis experiment conducted in the EUPHORE simulation chamber under simulated atmospheric conditions of low concentrations of limonene precursor and relative humidity, provides an overview of the method capabilities. Twenty-five compounds were positively or tentatively identified, nine being in both gaseous and particulate phases; and twelve, among them tricarboxylic acids, hydroxyl dicarboxylic acids and oxodicarboxylic acids, being detected for the first time.

  14. Comparison of extraction techniques and mass spectrometric ionization modes in the analysis of wine volatile carbonyls

    Energy Technology Data Exchange (ETDEWEB)

    Zapata, Julian; Mateo-Vivaracho, Laura; Cacho, Juan [Laboratory for Flavor Analysis and Enology, Institute of Engineering of Aragon, I3A, Department of Analytical Chemistry, Faculty of Sciences, University of Zaragoza, 50009 Zaragoza (Spain); Ferreira, Vicente, E-mail: vferre@unizar.es [Laboratory for Flavor Analysis and Enology, Institute of Engineering of Aragon, I3A, Department of Analytical Chemistry, Faculty of Sciences, University of Zaragoza, 50009 Zaragoza (Spain)

    2010-02-15

    This work presents a comparative study of the analytical characteristics of two methods for the analysis of carbonyl compounds in wine, both based on the derivatization with O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine hydrochloride (PFBHA). In the first method derivatives are formed in the solid phase extraction (SPE) cartridge in which the analytes have been previously isolated, while in the second method derivatives are formed in a solid phase microextraction (SPME) fibre saturated with vapors of the reagent and exposed to the sample headspace. In both cases detection has been carried out by electron impact (EI) or negative chemical ionization (NCI) mass spectrometry. The possibility of determining haloanisols simultaneously has been also considered. The method based on SPE presents, in general, better analytical properties than the SPME one. Although linearity was satisfactory for both methods (R{sup 2} > 0.99), repeatability of the SPE method (RSD < 10%) was better than that obtained with SPME (9% < RSD < 20%). Detection limits obtained with EI are better for the SPE method except for trihaloanisols, while with NCI detection limits for both strategies are comparable, although the SPME strategy presents worse results for ketones and methional. Detection limits are always lower with NCI, being the improvement most notable for SPME. Recovery experiments show that in the case of SPE, uncertainties are lower than 12% in all cases, while with the SPME method the imprecision plus the existence of matrix effects make the global uncertainty to be higher than 15%.

  15. Analysis of Volatile Metabolites Released by Staphylococcus Aureus using Gas Chromatography-Mass Spectrometry and Determination of its Antifungal Activity

    Directory of Open Access Journals (Sweden)

    Hayfaa Hussein Jaddoa

    2016-08-01

    Full Text Available Bacterial volatile organic compounds (VOCs have been considered as sensitive and specific biomarkers for bacterial detection in human specimens and culture media. The possibility of using VOCs markers as one of the largest groups of bacterial metabolites would open a new frontier for developing more efficient techniques in the diagnosis of bacterial infections. The aims of this research were analysis of the bioactive chemical products and evaluation of antibacterial and antifungal activity. Bioactives (chemical compounds often referred to as secondary metabolites were analyzed using gas chromatography-mass spectroscopy (GC-MS techniques, then the in vitro antibacterial and antifungal activity of the methanolic extract was evaluated. Thirty five bioactive compounds were identified in the methanolic extract of Staphylococcus aureus. GC-MS analysis of Staphylococcus aureus revealed the existence of the: Hexanoic acid , 2-methyl, 12,15-Octadecadiynoic acid , methyl ester, 1-Aminononadecane ,N-trifluoroacetyl-, N-[3-[N-Aziridyl]propylidene]hexylamine, N-(2,5-Dicyano-3,4-dihydro-2H-pyrrol-2-yl-acetamide, 3-Cyclohex-3-enyl-propionic acid, 1-Methyl-4-[nitromethyl]-4-piperidinol, 3-Azonia-5-hexyn-1-ol , N,N-dimethyl-O-acetyl-,bromide, 1-Hexadecanol -2-methyl-, 1-Propyl-3,6-diazahomoadamantan, 9-Borabicyclo[3.3.1]nonane , 9-mercapto-, Benzyl methyl ketone, L-Aspartic acid ,N-glycyl-, Aminoacetamide , N-methyl-N-[4-(1-pyrrolidinyl-2-butynyl]-, Tertbutyloxyformamide , N-methyl-N-[4-(1-pyrrolidinyl-2-butyn, 5,7-Dodecadiyn-1,12-diol, Deoxyspergualin, D-Streptamine , O-6-deoxy-α-D-glucopyranosyl-(1-4, dl-Citrulline, N-[3-Diethylaminopropyl]-4-oxo-1,2,3,4,5,6,7,8-octahydroqui, N-Propionyl-D-glucoseamine, Cystine, 3,4-Dihydrocoumarin ,6-fluoro-4,4-dimethyl-, 4-(2,5-Dihydro-3-methoxyphenylbutylamine, 3-methoxy-2-(1-methylethyl-5-(2-methylpropylpyrazine, Uric acid, Thiocyanic acid 4-methoxy-2,6-dimethyl-3-pyridyl ester, 12-Dimethylamino-10-oxododecanoic acid

  16. A Bayesian subgroup analysis using collections of ANOVA models.

    Science.gov (United States)

    Liu, Jinzhong; Sivaganesan, Siva; Laud, Purushottam W; Müller, Peter

    2017-03-20

    We develop a Bayesian approach to subgroup analysis using ANOVA models with multiple covariates, extending an earlier work. We assume a two-arm clinical trial with normally distributed response variable. We also assume that the covariates for subgroup finding are categorical and are a priori specified, and parsimonious easy-to-interpret subgroups are preferable. We represent the subgroups of interest by a collection of models and use a model selection approach to finding subgroups with heterogeneous effects. We develop suitable priors for the model space and use an objective Bayesian approach that yields multiplicity adjusted posterior probabilities for the models. We use a structured algorithm based on the posterior probabilities of the models to determine which subgroup effects to report. Frequentist operating characteristics of the approach are evaluated using simulation. While our approach is applicable in more general cases, we mainly focus on the 2 × 2 case of two covariates each at two levels for ease of presentation. The approach is illustrated using a real data example.

  17. Validation of SPME-GCMS method for the analysis of virgin olive oil volatiles responsible for sensory defects.

    Science.gov (United States)

    Romero, I; García-González, D L; Aparicio-Ruiz, R; Morales, M T

    2015-03-01

    Volatile compounds are responsible for the aroma of virgin olive oil and also for its quality. The high number and different nature of volatile compounds drive to the need of a reliable analytical method that allows their proper quantification to explain the standard method of panel test. Although there are some analytical solutions available, they have not been validated and the regulatory bodies are reluctant to adopt them since they can be subjected to unknown errors. In this regards, the European Union has encouraged the validation of these analytical tools through the research program Horizon2020, which involves gaining knowledge from the analytical properties of the chemical methods for sensory assessment. This work is focused on the analytical validation of the methodology used to determine the actual concentration of volatiles in virgin olive oils when applying SPME-GCMS. The validation process includes the calibration curves for 29 volatile compounds responsible for the most common sensory perceptions in virgin olive oils, the determination of their working ranges with linear response, the detection and quantification limits, the sensitivity, the accuracy estimated as trueness and precision and the selectivity. Sixty-seven percent of the compounds presented a relative standard deviation in repeatability lower than 10%, and this percentage rises to 95% in lampante virgin olive oils. The accuracy was established in 97% of the studied volatile compounds. Finally, an empirical example of the ability of the method to discriminate virgin olive oils of different categories (extra virgin, virgin, ordinary and lampante) by the quantification of their volatiles is provided.

  18. Aroma Volatile Compound Analysis of SPME Headspace and Extract Samples from Crabapple (Malus sp.) Fruit Using GC-MS

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Volatile compounds from the ripened crabapple fruit of six varieties (Red Splendor, Strawberry Parfait, Pink Spire, Radiant, Sparkler, and Flame) were analyzed by the use of the SPME/GC/MS method. The changes in the volatiles between the ripened and upon full maturity fruit states were studied in Red Splendor and Strawberry Parfait. An effort was made to summarize an effective method for searching and identifying new idioplasms containing a particular fruit aroma within Malus. A total of 37 compounds were identified from the sample. The main aroma volatiles of the six varieties of fruit were comprised of 2-hexenal, 3-hexenal, hexanal, 2,4-hexadienal, benzaldehyde, diethyl phthalate. The main volatile compound of the crabapple fruit was 2-hexenal, but the relative content percentages were different (45.37, 21.98, 33.56, 32.21, 38.60, and 45.88%). The aroma components accumulated differently as the fruits ripened. The relative content of aldehydes and esters decreased as alcohols increased after the Red Splendor and Strawberry Parfait fruit ripened. For Red Splendor, the main volatile was still 2-hexenal, but the relative content decreased to 42.89%, and the relative content of alcohols increased by 13.86% as aldehydes and esters declined by 12.16 and 7.18%, respectively. For Strawberry Parfait, the main volatile was changed to cyclohexanol, and the relative content increased to 46.43%, while the relative content of alcohols increased by 49.03% as aldehydes and esters declined by 23.74 and 9.34%, respectively.

  19. Assessment of regional influence from a petrochemical complex by modeling and fingerprint analysis of volatile organic compounds (VOCs)

    Science.gov (United States)

    Su, Yuan-Chang; Chen, Sheng-Po; Tong, Yu-Huei; Fan, Chen-Lun; Chen, Wei-Hao; Wang, Jia-Lin; Chang, Julius S.

    2016-09-01

    This study aimed to demonstrate a strategy to investigate the influence of volatile organic compounds (VOCs) on its neighboring districts from a gigantic petrochemical complex. Monitoring of the VOCs in the region was achieved by a nine-station network, dubbed photochemical assessment measurement stations (PAMS), which produced speciated mixing ratios of 54 non-methane hydrocarbons (NMHCs) to represent VOCs with an hourly resolution within a 20 km radius. One-year (2013/10/1-2014/9/30) worth of PAMS data from the network were used in forms of total NMHCs (called PAMS-TNMHC) and speciated mixing ratios. Three dimensional modeling coupled with PAMS measurements successfully elucidated how the study domain was affected by the petrochemical complex and distant sources under three typical seasonal wind patterns: northeast monsoonal, southwest monsoonal, and local-circulation. More exquisite analysis of influence on the neighboring districts was permitted with the use of speciated mixing ratios of VOCs provided by the PAMS network. The ratios of ethylene/acetylene (E/A) > 3 and propylene/acetylene (P/A) > 1.5 were used as indicators to reveal the PAMS sites affected by the petrochemical emissions. Consequently, the hourly speciated data from the nine PAMS sites enabled a finer assessment of the districts affected by the complex to calculate the percent time of influence (dubbed TI%) for all the sites (districts). It was found that the region was more affected by the complex under both the northeast monsoonal and the local-circulation wind types with some of the PAMS sites greater than 5% for the TI%. By contrast, influence on the region was found minimal under the southwest monsoonal flow with the TI% small than 1.5% across all sites. This study successfully devised a method of assessment with the use of speciated measurements of selected VOCs and modeling to assess the influence of a prominent source on the neighboring districts by filtering out irrelevant sources under

  20. Characterization of thermal desorption with the Deans-switch technique in gas chromatographic analysis of volatile organic compounds.

    Science.gov (United States)

    Ou-Yang, Chang-Feng; Huang, Ying-Xue; Huang, Ting-Jyun; Chen, Yong-Shen; Wang, Chieh-Heng; Wang, Jia-Lin

    2016-09-02

    This study presents a novel application based on the Deans-switch cutting technique to characterize the thermal-desorption (TD) properties for gas chromatographic (GC) analysis of ambient volatile organic compounds (VOCs). Flash-heating of the sorbent bed at high temperatures to desorb trapped VOCs to GC may easily produce severe asymmetric or tailing GC peaks affecting resolution and sensitivity if care is not taken to optimize the TD conditions. The TD peak without GC separation was first examined for the quality of the TD peak by analyzing a standard gas mixture from C2 to C12 at ppb level. The Deans switch was later applied in two different stages. First, it was used to cut the trailing tail of the TD peak, which, although significantly improved the GC peak symmetry, led to more loss of the higher boiling compounds than the low boiling ones, thus suggesting compound discrimination. Subsequently, the Deans switch was used to dissect the TD peak into six 30s slices in series, and an uneven distribution in composition between the slices were found. A progressive decrease in low boiling compounds and increase in higher boiling ones across the slices indicated severe inhomogeneity in the TD profile. This finding provided a clear evidence to answer the discrimination problem found with the tail cutting approach to improve peak symmetry. Through the use of the innovated slicing method based on the Deans-switch cutting technique, optimization of TD injection for highly resolved, symmetric and non-discriminated GC peaks can now be more quantitatively assessed and guided.

  1. 75 FR 40839 - Agency Information Collection Activities; Proposed Collection; Comment Request; Hazard Analysis...

    Science.gov (United States)

    2010-07-14

    ... procedures to fruit and vegetable juice processing. HACCP is a preventative system of hazard control that can be used by all food processors to ensure the safety of their products to consumers. A HACCP system of... and recordkeeping are essential parts of any HACCP system. The information collection requirements...

  2. 78 FR 69689 - Agency Information Collection Activities; Proposed Collection; Comment Request; Hazard Analysis...

    Science.gov (United States)

    2013-11-20

    ... principles to the processing of fruit and vegetable juices. HACCP is a preventive system of hazard control... regulations for the efficient enforcement of that act. The rationale in establishing an HACCP system of... development and recordkeeping are essential parts of any HACCP system. The information collection...

  3. Separation and analysis of trace volatile formaldehyde in aquatic products by a MoO₃/polypyrrole intercalative sampling adsorbent with thermal desorption gas chromatography and mass spectrometry.

    Science.gov (United States)

    Ma, Yunjian; Zhao, Cheng; Zhan, Yisen; Li, Jianbin; Zhang, Zhuomin; Li, Gongke

    2015-05-01

    An in situ embedded synthesis strategy was developed for the preparation of a MoO3 /polypyrrole intercalative sampling adsorbent for the separation and analysis of trace volatile formaldehyde in aquatic products. Structural and morphological characteristics of the MoO3 /polypyrrole intercalative adsorbent were investigated by a series of characterization methods. The MoO3 /polypyrrole sampling adsorbent possessed a higher sampling capacity and selectivity for polar formaldehyde than commonly used commercial adsorbent Tenax TA. Finally, the MoO3 /polypyrrole adsorbent was packed in the thermal desorption tube that was directly coupled to gas chromatography with mass spectrometry for the analysis of trace volatile formaldehyde in aquatic products. Trace volatile formaldehyde from real aquatic products could be selectively sampled and quantified to be 0.43-6.6 mg/kg. The detection limit was achieved as 0.004 μg/L by this method. Good recoveries for spiked aquatic products were achieved in range of 75.0-108% with relative standard deviations of 1.2-9.0%. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Differentiation of the volatile profile of microbiologically contaminated canned tomatoes by dynamic headspace extraction followed by gas chromatography-mass spectrometry analysis.

    Science.gov (United States)

    Bianchi, F; Careri, M; Mangia, A; Mattarozzi, M; Musci, M; Concina, I; Falasconi, M; Gobbi, E; Pardo, M; Sberveglieri, G

    2009-01-15

    The aromatic profile of microbiologically contaminated canned tomatoes was analyzed by the dynamic headspace extraction technique coupled with gas chromatography-mass spectrometry. Canned tomatoes contaminated with Escherichia coli, Saccharomyces cerevisiae and Aspergillus carbonarius were analyzed after 2 and 7 days. About 100 volatiles were detected, among which alcohols, aldehydes and ketones were the most abundant compounds. Gas chromatographic peak areas were used for statistical purposes. First, principal component analysis was carried out in order to visualize data trends and clusters. Then, linear discriminant analysis was performed in order to detect the set of volatile compounds ables to differentiate groups of analyzed samples. Five volatile compounds, i.e. ethanol, beta-myrcene, o-methyl styrene, 6-methyl-5-hepten-2-ol and 1-octanol, were found to be able to better discriminate between uncontaminated and contaminated samples. Prediction ability of the calculated model was estimated to be 100% by the "leave-one-out" cross-validation. An electronic nose device was then used to analyze the same contaminated and not contaminated canned tomato samples. Preliminary results were compared with those obtained by dynamic headspace gas chromatography-mass spectrometry, showing a good agreement.

  5. Direct thermal desorption in the analysis of cheese volatiles by gas chromatography and gas chromatography-mass spectrometry: comparison with simultaneous distillation-extraction and dynamic headspace.

    Science.gov (United States)

    Valero, E; Sanz, J; Martínez-Castro, I

    2001-06-01

    Direct thermal desorption (DTD) has been used as a technique for extracting volatile components of cheese as a preliminary step to their gas chromatographic (GC) analysis. In this study, it is applied to different cheese varieties: Camembert, blue, Chaumes, and La Serena. Volatiles are also extracted using other techniques such as simultaneous distillation-extraction and dynamic headspace. Separation and identification of the cheese components are carried out by GC-mass spectrometry. Approximately 100 compounds are detected in the examined cheeses. The described results show that DTD is fast, simple, and easy to automate; requires only a small amount of sample (approximately 50 mg); and affords quantitative information about the main groups of compounds present in cheeses.

  6. Volatile and non-volatile/semi-volatile compounds and in vitro bioactive properties of Chilean Ulmo (Eucryphia cordifolia Cav.) honey.

    Science.gov (United States)

    Acevedo, Francisca; Torres, Paulina; Oomah, B Dave; de Alencar, Severino Matias; Massarioli, Adna Prado; Martín-Venegas, Raquel; Albarral-Ávila, Vicenta; Burgos-Díaz, César; Ferrer, Ruth; Rubilar, Mónica

    2017-04-01

    Ulmo honey originating from Eucryphia cordifolia tree, known locally in the Araucania region as the Ulmo tree is a natural product with valuable nutritional and medicinal qualities. It has been used in the Mapuche culture to treat infections. This study aimed to identify the volatile and non-volatile/semi-volatile compounds of Ulmo honey and elucidate its in vitro biological properties by evaluating its antioxidant, antibacterial, antiproliferative and hemolytic properties and cytotoxicity in Caco-2 cells. Headspace volatiles of Ulmo honey were isolated by solid-phase microextraction (SPME); non-volatiles/semi-volatiles were obtained by removing all saccharides with acidified water and the compounds were identified by GC/MS analysis. Ulmo honey volatiles consisted of 50 compounds predominated by 20 flavor components. Two of the volatile compounds, lyrame and anethol have never been reported before as honey compounds. The non-volatile/semi-volatile components of Ulmo honey comprised 27 compounds including 13 benzene derivatives accounting 75% of the total peak area. Ulmo honey exhibited weak antioxidant activity but strong antibacterial activity particularly against gram-negative bacteria and methicillin-resistant Staphylococcus aureus (MRSA), the main strain involved in wounds and skin infections. At concentrations >0.5%, Ulmo honey reduced Caco-2 cell viability, released lactate dehydrogenase (LDH) and increased reactive oxygen species (ROS) production in a dose dependent manner in the presence of foetal bovine serum (FBS). The wide array of volatile and non-volatile/semi-volatile constituents of Ulmo honey rich in benzene derivatives may partly account for its strong antibacterial and antiproliferative properties important for its therapeutic use. Our results indicate that Ulmo honey can potentially inhibit cancer growth at least partly by modulating oxidative stress. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Age Analysis of Public Library Collections. Final Report.

    Science.gov (United States)

    Wallace, Danny P.; And Others

    The use of information regarding the ages of library items is a standard component of many approaches to weeding library collections, and has a long history in the literature of collection management. Current and past approaches to using aging information to make weeding decisions make use of very arbitrary decision criteria. This study examined…

  8. Brief Analysis on Institution of Rural Collective Construction Land Transfer

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    From the viewpoint of strengthening the government management and control of rural collective construction land transfer,this paper gives relevant definitions and puts forward institution and policy of construction land for township enterprises and rural housing land. It is expected to provide institutional guarantee for standardizing the market order of rural collective construction land use right transfer.

  9. Analysis of volatile compounds of Iberian dry-cured loins with different intramuscular fat contents using SPME-DED.

    Science.gov (United States)

    Ventanas, Sonia; Estevez, Mario; Andrés, Ana I; Ruiz, Jorge

    2008-05-01

    In order to study the effect of both, ripening time and IMF content on the volatile profile of Iberian dry-cured loin, volatile compounds from the headspace of 10 Iberian dry-cured loins with different intramuscular fat contents (IMF), low (average IMF content of 2.3%) and high (average IMF content of 6.7%), at days 40 and 55 of the ripening process were analysed using SPME coupled to a direct extraction device (DED) and subsequent gas chromatography/mass spectrometry (GC/MS). Chromatographic areas of the main chemical families detected (hydrocarbons, aldehydes, alcohols, ketones and acids) increased with ripening time. A higher total chromatographic area was detected in the headspace of high IMF loins compared to low IMF ones. Several volatile compounds derived from lipid oxidative reactions, such as hexanol, octanal, (E,E)-2,4-heptadienal or (E)-2-decenal, and others from the degradation of certain amino acids, such as dimethylsulfide, 3-methylbutanal or phenylacetaldehyde, showed higher chromatographic areas in the headspace of high IMF loins than in low IMF ones. Thus, IMF content could influence both the generation of volatile compounds and the transfer of such compounds from the product matrix to the headspace.

  10. Functional analysis of a tomato salicylic acid methyl transferase and its role in synthesis of the flavor volatile methyl salicylate

    Science.gov (United States)

    Methyl salicylate (MeSA) is a volatile plant secondary metabolite that is an important contributor to taste and scent of many fruits and flowers. It is synthesized from salicylic acid (SA), a phytohormone that contributes to plant pathogen defense. MeSA is synthesized by members of a family of O-met...

  11. Combined transcript and metabolite analysis reveals genes involved in spider mite induced volatile formation in cucumber plants

    NARCIS (Netherlands)

    Mercke, P.; Kappers, I.F.; Verstappen, F.W.A.; Vorst, O.F.J.; Dicke, M.; Bouwmeester, H.J.

    2004-01-01

    Many plants have an indirect defense against herbivores by emitting volatiles that attract carnivorous enemies of the herbivores. In cucumber (Cucumis sativus) the production of carnivore attractants can be induced by herbivory or jasmonic acid spraying. From the leaves of cucumber plants with and

  12. Analysis of volatile organic compounds in water by dynamic stripping, thermal desorption, cryofocusing, and capillary gas chromatography (journal version)

    Energy Technology Data Exchange (ETDEWEB)

    Vandegrift, S.A.

    1988-01-01

    A dynamic headspace procedure developed for the determination of volatile organic compounds (VOCs) in water is described. The VOCs are purged from a water sample with an inert gas, transferring them to a tube packed with Tenax adsorbent. The adsorbent tube, or trap, is thermally desorbed, the analytes cryofocused, and subsequently transferred to a capillary column gas chromatograph.

  13. Characterization of Four Popular Sweet Cherry Cultivars Grown in Greece by Volatile Compound and Physicochemical Data Analysis and Sensory Evaluation

    Directory of Open Access Journals (Sweden)

    Maria V. Vavoura

    2015-01-01

    Full Text Available Volatile compounds, physicochemical and sensory attributes of four sweet cherry cultivars (Canada giant, Ferrovia, Lapins and Skeena grown in Northern Greece were determined. Eighteen volatile compounds were identified and semi-quantified in cherries using solid phase micro extraction in combination with gas chromatography/mass spectrometry (SPME-GC/MS. Carbonyl compounds were the most abundant in sweet cherry aroma, followed by alcohols, esters and hydrocarbons/terpenes. Cherry cultivars in order of increasing amounts of volatiles were: Lapins < Canada giant < Ferrovia < Skeena. Physicochemical parameters determined included: titratable acidity (TA, pH, total soluble solids (TSS, maturity index (MI and total phenolic content (TPC. TA ranged between 0.21 and 0.28 g malic acid/100 g fresh weight (FW. The pH ranged between 3.81 and 3.96. TSS ranged between 13.00 and 16.00 °Brix. MI ranged between 51.8 and 75.0. TPC ranged between 95.14 and 170.35 mg gallic acid equivalents (GAE/100 g FW. Sensory evaluation showed that cherry colour, in order of increasing intensity, was: Canada giant < Ferrovia < Lapins < Skeena. Respective order for cherry firmness was: Canada giant < Lapins ≤ Ferrovia < Skeena and for flavour: Lapins < Canada giant < Skeena ≤ Ferrovia. Correlation of volatiles to physicochemical and sensory attributes showed varying trends.

  14. Chemical mass balance of 300 °C non-volatile particles at the tropospheric research site Melpitz, Germany

    Science.gov (United States)

    Poulain, L.; Birmili, W.; Canonaco, F.; Crippa, M.; Wu, Z. J.; Nordmann, S.; Spindler, G.; Prévôt, A. S. H.; Wiedensohler, A.; Herrmann, H.

    2014-09-01

    In the fine-particle mode (aerodynamic diameter MAAP), and an aerosol mass spectrometer (AMS). The data were collected during two atmospheric field experiments in May-June 2008 as well as February-March 2009. As a basic result, we detected average non-volatile particle-volume fractions of 11 ± 3% (2008) and 17 ± 8% (2009). In both periods, BC was in close linear correlation with the non-volatile fraction, but not sufficient to quantitatively explain the non-volatile particle mass concentration. Based on the assumption that BC is not altered by the heating process, the non-volatile particle mass fraction could be explained by the sum of black carbon (47% in summer, 59% in winter) and a non-volatile organic contribution estimated as part of the low-volatility oxygenated organic aerosol (LV-OOA) (53% in summer, 41% in winter); the latter was identified from AMS data by factor analysis. Our results suggest that LV-OOA was more volatile in summer (May-June 2008) than in winter (February-March 2009) which was linked to a difference in oxidation levels (lower in summer). Although carbonaceous compounds dominated the sub-μm non-volatile particle mass fraction most of the time, a cross-sensitivity to partially volatile aerosol particles of maritime origin could be seen. These marine particles could be distinguished, however from the carbonaceous particles by a characteristic particle volume-size distribution. The paper discusses the uncertainty of the volatility measurements and outlines the possible merits of volatility analysis as part of continuous atmospheric aerosol measurements.

  15. Volatiles produced by Staphylococcus xylosus and Staphylococcus carnosus during growth in sausage minces

    DEFF Research Database (Denmark)

    Stahnke, Marie Louise Heller

    1999-01-01

    Aseptic model minces were inoculated with commercial samples of either Staphylococcus xylosus or Staphylococcus carnosus. Volatiles produced by the cultures were collected during growth by diffusive sampling onto adsorbent traps, identified by thermal desorption-gas chromatography-mass spectrometry...... and quantified by thermal desorption-gas chromatography-flame ionisation. The data were analysed by principal component analysis. The study showed that both starter cultures produced a large number of volatiles in concentrations of sensory importance. Almost all of the major volatiles resulted from amino acid...... degradation, suggesting that the effect of Staphylococcus starter cultures on flavour quality is much related to their ability of catabolizing amino acids. With the exception of diacetyl, acetoin and 2-methyl-1-butanol, both cultures formed the same volatiles. Diacetyl and acetoin were not produced...

  16. Analysis of Savannah Survey Sediment Collections of 30 Sep 04

    Energy Technology Data Exchange (ETDEWEB)

    Wimer, N; Hutcheon, I; Esser, B; Ramon, E

    2004-12-03

    This report summarizes laboratory radiochemical analyses of sediment samples collected by the Defense Threat Reduction Agency during the DoD Savannah Survey operations of Sep 04. The analytic goal was to determine if Wassaw Sound sediment collections of 30 Sep 04 display evidence for local anthropogenic uranium, as distinct from the recognized regional background stemming from the Savannah River Site (SRS). Radiochemical methods were selected to maximize detection sensitivity for such anthropogenic uranium. Within the suite of twelve collections, there would be evidence for a localized source if individual collections were to differ from the population as a whole. If in fact non-natural uranium were observed, definitive determination of whether the source was SRS effluent or a localized release would likely involve additional field sampling. These collections were logged by the LLNL Forensics Science Center, photographed, and laboratory chain-of-custody was begun. The inventory received at LLNL is reported in Table 1. The separate collections were not assigned any relative priority among them. LLNL has separately reviewed detailed records of the item in question, and determined what materials are involved and what radiochemical assays are of value. Attempting quantitative estimates of source-item material release, transport, and collection levels would be quite uncertain. Rather, present assays examine for departure from natural background isotopic compositions. To summarize the findings, analyses for all collections displayed natural uranium isotopic composition--considering the {sup 238}U/{sup 235}U and {sup 236}U/{sup 235}U ratios--within measurement uncertainties, which were quite low. No one collection or set of collections stood apart from the others in its uranium isotopes. These {sup 238}U/{sup 235}U data uncertainty levels also determined with 99.5% confidence (a three-standard-deviation determination) that no more than 0.46% of the total uranium present

  17. Analysis of roasted and unroasted Pistacia terebinthus volatiles using direct thermal desorption-GCxGC-TOF/MS.

    Science.gov (United States)

    Gogus, F; Ozel, M Z; Kocak, D; Hamilton, J F; Lewis, A C

    2011-12-01

    The objective of this study was to determine the effects of roasting time on volatile components of Pistacia terebinthus L., a fruit growing wild in Turkey. The whole fruit samples were pan roasted for 0, 5, 10, 15, 20 and 25min at 200°C. Volatile compounds were isolated and identified using the direct thermal desorption (DTD) method coupled with comprehensive gas chromatography - time of flight mass spectrometry (GCxGC-TOF/MS). The major components of the fresh hull of P. terebinthus were α-pinene (10.37%), limonene (8.93%), β-pinene (5.53%), 2-carene (4.47%) and γ-muurolene (4.29%). Eighty-three constituents were characterised from the volatiles of fresh whole P. terebinthus fruits obtained by direct thermal desorption with α-pinene (9.62%), limonene (5.54%), γ-cadinane (5.48%), β-pinene (5.46%), β-caryophyllene (5.24%) being the major constituents. The type and the number of constituents characterised were observed to change with differing roasting times. Limonene (5.56%), α-pinene (4.84%), 5-methylfurfural (4.78%), 5-hydroxymethylfurfural (5-HMF, 3.89%), dimethylmetoxyfuranone (3.67%) and 3-methyl-2(5H)furanone (3.12%) were identified as the major components among the 104 compounds characterised in the volatiles of P. terebinthus, roasted for 25min. In addition, volatiles of fully roasted P. terebinthus fruits contained furans and furanones (15.42%), pyridines (4.45%) and benzene derivatives (3.81%) as the major groups.

  18. Integrated Data Collection Analysis (IDCA) program--KClO4/Dodecane Mixture

    Energy Technology Data Exchange (ETDEWEB)

    Sandstrom, Mary M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Brown, Geoffrey W. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Preston, Daniel N. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Pollard, Colin J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Warner, Kirstin F. [Naval Surface Warfare Center (NSWC), Indian Head, MD (United States). Indian Head Division; Sorensen, Daniel N. [Naval Surface Warfare Center (NSWC), Indian Head, MD (United States). Indian Head Division; Remmers, Daniel L. [Naval Surface Warfare Center (NSWC), Indian Head, MD (United States). Indian Head Division; Shelley, Timothy J. [Air Force Research Lab. (AFRL), Tyndall AFB, FL (United States); Reyes, Jose A. [Applied Research Associates, Tyndall AFB, FL (United States); Hsu, Peter C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Reynolds, John G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2012-05-11

    The Integrated Data Collection Analysis (IDCA) program is conducting a proficiency study for Small- Scale Safety and Thermal (SSST) testing of homemade explosives (HMEs). Described here are the results for impact, friction, electrostatic discharge, and differential scanning calorimetry analysis of a mixture of KClO4 and dodecane—KClO4/dodecane mixture. This material was selected because of the challenge of performing SSST testing of a mixture of solid and liquid materials. The mixture was found to: 1) be less sensitive to impact than RDX, and PETN, 2) less sensitive to friction than RDX and PETN, and 3) less sensitive to spark than RDX and PETN. The thermal analysis showed little or no exothermic features suggesting that the dodecane volatilized at low temperatures. A prominent endothermic feature was observed and assigned to a phase transition of KClO4. This effort, funded by the Department of Homeland Security (DHS), ultimately will put the issues of safe handling of these materials in perspective with standard military explosives. The study is adding SSST testing results for a broad suite of different HMEs to the literature. Ultimately the study has the potential to suggest new guidelines and methods and possibly establish the SSST testing accuracies needed to develop safe handling practices for HMEs. Each participating testing laboratory uses identical test materials and preparation methods wherever possible. Note, however, the test procedures differ among the laboratories. The results are compared among the laboratories and then compared to historical data from various sources. The testing performers involved for the KClO4/dodecane mixture are Lawrence Livermore National Laboratory (LLNL), Los Alamos National Laboratory (LANL), Indian Head Division, Naval Surface Warfare Center, (NSWC IHD), and Air Force Research Laboratory (AFRL/RXQL). These tests are conducted as a proficiency study in order to establish some

  19. Confined direct analysis in real time ion source and its applications in analysis of volatile organic compounds of Citrus limon (lemon) and Allium cepa (onion).

    Science.gov (United States)

    Li, Yue

    2012-05-30

    The DART (direct analysis in real time) ion source is a novel atmospheric pressure ionization technique that enables efficient ionization of gases, liquids and solids with high throughput. A major limit to its wider application in the analysis of gases is its poor detection sensitivity caused by open-air sampling. In this study, a confined interface between the DART ion source outlet and mass spectrometer sampling orifice was developed, where the plasma generated by the atmospheric pressure glow discharge collides and ionizes gas-phase molecules in a Tee-shaped flow tube instead of in open air. It leads to significant increase of collision reaction probability between high energy metastable molecules and analytes. The experimental results show that the ionization efficiency was increased at least by two orders of magnitude. This technique was then applied in the real time analysis of volatile organic compounds (VOCs) of Citrus Limon (lemon) and wounded Allium Cepa (onion). The confined DART ion source was proved to be a powerful tool for the studies of plant metabolomics.

  20. Comparative Characterization of Aroma Volatiles and Related Gene Expression Analysis at Vegetative and Mature Stages in Basmati and Non-Basmati Rice (Oryza sativa L.) Cultivars.

    Science.gov (United States)

    Hinge, Vidya; Patil, Hemant; Nadaf, Altafhusain

    2016-02-01

    Aroma volatiles in Basmati-370, Ambemohar-157 (non-basmati scented), and IR-64 (non-scented) rice cultivars were qualitatively and quantitatively analyzed at vegetative and maturity stages to study their differential accumulation using headspace solid-phase microextraction, followed by gas chromatography mass spectrometry (HS-SPME-GCMS) with selected ion monitoring (SIM) approach. In addition, expression analysis of major aroma volatile 2-acetyl-1-pyrroline (2AP)-related genes, betaine aldehyde dehydrogenase 2 (badh2) and Δ(1)-pyrolline-5-carboxylic acid synthetase (P5CS), were studied by real-time PCR. Maximum number of volatiles recorded at vegetative (72-58) than at mature stage (54-39). Twenty new compounds (12 in scented and 8 in both) were reported in rice. N-containing aromatic compounds were major distinguishing class separating scented from non-scented. Among quantified 26 volatiles, 14 odor-active compounds distinguished vegetative and mature stage. Limit of detection (LOD) and limit of quantification (LOQ) for 2AP was 0.001 mg/kg of 2AP and 0.01 g of rice, respectively. 2AP accumulation in mature grains was found three times more than in leaves of scented rice. Positive correlation of 2AP with 2-pentylfuran, 6-methyl-5-hepten-2-one, and (E)-2-nonenal suggests their major role as aroma contributors. The badh2 expression was inversely and P5CS expression was positively correlated with 2AP accumulation in scented over non-scented cultivar.

  1. Volatile signals during pregnancy.

    Science.gov (United States)

    Vaglio, Stefano

    2010-01-01

    Scents play a key role in mediating reproductive interactions in many vertebrates including mammals. Nowadays, several studies indicate that humans seem to use remarkably olfactory communication and are even able to produce and perceive pheromones. Furthermore, over the past several years, it became increasingly clear that pheromone-like chemical signals probably play a role in offspring identification and mother recognition. Recently developed technical procedures (solid-phase microextraction and dynamic headspace extraction) now allow investigators to characterize volatile compounds with high reliability. We analyzed the volatile compounds in sweat patch samples collected from the para-axillary and nipple-areola regions of women during pregnancy and after childbirth. We hypothesized that, at the time of birth and during the first weeks of life, the distinctive olfactory pattern of the para-axillary area is probably useful to newborn babies for recognizing and distinguishing their own mother, whereas the characteristic pattern of the nipple-areola region is probably useful as a guide to nourishment.

  2. The Volatile Composition of Portuguese Propolis Towards its Origin Discrimination

    Directory of Open Access Journals (Sweden)

    Soraia I. Falcão

    2016-03-01

    Full Text Available The volatiles from thirty six propolis samples collected from six different geographical locations in Portugal (mainland, Azores archipelago and Madeira Island were evaluated. Populus x canadensis Moenchen leaf-buds and Cistus ladanifer L. branches essential oils were comparatively analysed. The essential oils were isolated by hydrodistillation and analysed by Gas Chromatography (GC and Gas Chromatography-Mass Spectrometry (GC-MS. Cluster analysis based on propolis samples volatiles chemical composition defined three main clusters, not related to sample site collection. Cluster I grouped 28 samples with high relative amounts of oxygen-containing sesquiterpenes (20-77%, while cluster II grouped 7 samples rich in oxygen-containing monoterpenes (9-65% and the only sample from cluster III was monoterpene hydrocarbons rich (26%. Although Populus x canadensis and Cistus ladanifer were associated as resin sources of Portuguese propolis, other Populus species as well as plants like Juniperus genus may contribute to the resin in specific geographical locations.

  3. Analysis of the Multi-Phase Copying Garbage Collection Algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Podhorszki, Norbert [ORNL

    2009-01-01

    The multi-phase copying garbage collection was designed to avoid the need for large amount of reserved memory usually required for the copying types of garbage collection algorithms. The collection is performed in multiple phases using the available free memory. This paper proves that the number of phases depends on the size of the reserved memory and the ratio of the garbage and accessible objects. The performance of the implemented algorithm is tested in a fine-grained parallel Prolog system. We find that reserving only 10% of memory for garbage collection is sufficient for good performance in practice. Additionally, an improvement of the generic algorithm specifically for the tested parallel Prolog system is described.

  4. Phytoplankton Monitoring Network - Phytoplankton Analysis with Associated Collection Information

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A qualitative collection of data that includes salinity, temperature, phytoplankton counts and abundance ratios obtained from surface tows in the estuarine and...

  5. Environmental-benefit analysis of two urban waste collection systems.

    Science.gov (United States)

    Aranda Usón, Alfonso; Ferreira, Germán; Zambrana Vásquez, David; Zabalza Bribián, Ignacio; Llera Sastresa, Eva

    2013-10-01

    Sustainable transportation infrastructure and travel policies aim to optimise the use of transportation systems to achieve economic and related social and environmental goals. To this end, a novel methodology based on life cycle assessment (LCA) has been developed in this study, with the aim of quantifying, in terms of CO2 emissions equivalent, the impact associated with different alternatives of waste collection systems in different urban typologies. This new approach is focussed on saving energy and raw materials and reducing the environmental impact associated with the waste collection system in urban areas, as well as allowing the design and planning of the best available technologies and most environment-friendly management. The methodology considers a large variety of variables from the point of view of sustainable urban transport such as the location and size of the urban area, the amount of solid waste generated, the level of social awareness on waste separation procedures, the distance between houses and waste collection points and the distance from the latter to the possible recovery plants and/or landfills, taking into account the material and energy recovery ratio within an integrated waste management system. As a case study, two different waste collection systems have been evaluated with this methodology in the ecocity Valdespartera located in Zaragoza, Spain, consisting of approximately 10,000 homes: (i) a system based on traditional truck transportation and manual collection, and (ii) a stationary vacuum waste collection system. Results show that, when operating at loads close to 100%, the stationary collection system has the best environmental performance in comparison with the conventional system. In contrast, when operating at load factors around 13% the environmental benefits in terms of net CO2-eq. emissions for the stationary collection system are around 60% lower in comparison with the conventional one. Copyright © 2013 Elsevier B.V. All

  6. Volatile Organic Compounds (VOCs)

    Science.gov (United States)

    ... Contact Us Share Volatile Organic Compounds' Impact on Indoor Air Quality On this page: Introduction Sources Health Effects Levels in Homes Steps to Reduce Exposure Standards or Guidelines Additional Resources Introduction Volatile organic compounds ( ...

  7. Volatile Organic Compounds Identified in Post-Flight Air Analysis of the Multipurpose Logistics Module from International Space Station

    Science.gov (United States)

    Peterson, B.; Wheeler, R.

    Bioregenerative systems involve storing and processing waste along with atmospheric management. The MPLM, Multipurpose Logistics Module, is a reusable logistics carrier and primary delivery system used to resupply the International Space Station (ISS) and return Station cargo that requires a pressurized environment. The cylindrical module is approximately 6.4 meters long, 4.6 meters in diameter, and weighs almost 4,082kg. The module provides storage and additional workspace for up to two astronauts when docked to the ISS. It can carry up to 9,072 kg of supplies, science experiments, spare parts and other logistical components for ISS. There is concern for a potentially hazardous condition caused by contamination of the atmosphere in the MPLM upon return from orbit. This would be largely due to unforeseen spills or container leakage. This has led to the need for special care in handling the returned module prior to processing the module for its next flight. Prior to opening the MPLM, atmospheric samples are analyzed for trace volatile organic compounds, VOC's. It is noted that our analyses also reflect the atmosphere in the ISS on that day of closure. With the re turn of STS-108, 12th ISS Flight (UF1), the analysis showed 24 PPM of methane. This corresponds to the high levels on space station during a time period when the air filtration system was shut off. Chemical characterization of atmospheres on the ISS and MPLM provide useful information for concerns with plant growth experiments on ISS. Work with closed plant growth chambers show potential for VOC's to accumulate to toxic levels for plants. The ethylene levels for 4 MPLM analyses over the course on one year were measured at, 0.070, 0.017, 0.012 and 0.007 PPM. Phytochemical such as ethylene are detected with natural plant physiological events such as flowering and as a result of plant damage or from decaying food. A build up of VOC's may contribute to phytotoxic effects for the plant growth experiments or

  8. Belief biases and volatility of assets

    Science.gov (United States)

    Lei-Sun, Wen-Zou, Hui

    2014-10-01

    Based on an overlapping generation model, this paper introduces the noise traders with belief biases and rational traders. With an equilibrium analysis, this paper examines the volatility of risky asset. The results show that the belief biases, the probability of economy state, and the domain capability are all the factors that have effects on the volatility of the market.

  9. Analyzing volatile compounds in dairy products

    Science.gov (United States)

    Volatile compounds give the first indication of the flavor in a dairy product. Volatiles are isolated from the sample matrix and then analyzed by chromatography, sensory methods, or an electronic nose. Isolation may be performed by solvent extraction or headspace analysis, and gas chromatography i...

  10. Herbivore-induced blueberry volatiles and intra-plant signaling.

    Science.gov (United States)

    Rodriguez-Saona, Cesar R

    2011-12-18

    Herbivore-induced plant volatiles (HIPVs) are commonly emitted from plants after herbivore attack. These HIPVs are mainly regulated by the defensive plant hormone jasmonic acid (JA) and its volatile derivative methyl jasmonate (MeJA). Over the past 3 decades researchers have documented that HIPVs can repel or attract herbivores, attract the natural enemies of herbivores, and in some cases they can induce or prime plant defenses prior to herbivore attack. In a recent paper, I reported that feeding by gypsy moth caterpillars, exogenous MeJA application, and mechanical damage induce the emissions of volatiles from blueberry plants, albeit differently. In addition, blueberry branches respond to HIPVs emitted from neighboring branches of the same plant by increasing the levels of JA and resistance to herbivores (i.e., direct plant defenses), and by priming volatile emissions (i.e., indirect plant defenses). Similar findings have been reported recently for sagebrush, poplar, and lima beans. Here, I describe a push-pull method for collecting blueberry volatiles induced by herbivore (gypsy moth) feeding, exogenous MeJA application, and mechanical damage. The volatile collection unit consists of a 4 L volatile collection chamber, a 2-piece guillotine, an air delivery system that purifies incoming air, and a vacuum system connected to a trap filled with Super-Q adsorbent to collect volatiles. Volatiles collected in Super-Q traps are eluted with dichloromethane and then separated and quantified using Gas Chromatography (GC). This volatile collection method was used in my study to investigate the volatile response of undamaged branches to exposure to volatiles from herbivore-damaged branches within blueberry plants. These methods are described here. Briefly, undamaged blueberry branches are exposed to HIPVs from neighboring branches within the same plant. Using the same techniques described above, volatiles emitted from branches after exposure to HIPVs are collected and

  11. GC-MS analysis of essential oils from Salvia officinalis L.: comparison of extraction methods of the volatile components.

    Science.gov (United States)

    Baj, Tomasz; Ludwiczuk, Agnieszka; Sieniawska, Elwira; Skalicka-Woźniak, Krystyna; Widelski, Jarosław; Zieba, Krzysztof; Głowniak, Kazimierz

    2013-01-01

    In this paper, comparison of the volatile components composition in the samples obtained by hydrodistillation and solid-phase microextraction of Salvia officinalis was described. Different sample preparation techniques showed considerable differences in volatiles composition, especially with respect to sesqui- and diterpenoids. The comparison of the sage essential oil obtained by hydrodistillation in the Deryng and Clevenger type apparatus, according to the pharmacopoeial methods (FP VI and VII), showed the presence of the same terpenoids in both essential oils, however, the relative percentage composition of the components were different. These differences are caused by the different extraction times used in both methods. Since each essential oil to be admitted to medicinal use should meet requirements regarding the composition of major chemical components, the minimum time for the hydrodistillation of the essential oils from sage should be 1 h.

  12. Comment on ‘multifractal diffusion entropy analysis on stock volatility in financial markets’ [Physica A 391 (2012) 5739-5745

    Science.gov (United States)

    Morozov, A. Yu.

    2013-05-01

    In their recent article ‘multifractal diffusion entropy analysis on stock volatility in financial markets’ Huang, Shang and Zhao (2012) [6] suggested a generalization of the diffusion entropy analysis method with the main goal of being able to reveal scaling exponents for multifractal times series. The main idea seems to be replacing the Shannon entropy by the Rényi entropy, which is a one-parametric family of entropies. The authors claim that based on their method they are able to separate long range and short correlations of financial market multifractal time series. In this comment I show that the suggested new method does not bring much valuable information in obtaining the correct scaling for a multifractal/mono-fractal process beyond the original diffusion entropy analysis method. I also argue that the mathematical properties of the multifractal diffusion entropy analysis should be carefully explored to avoid possible numerical artefacts when implementing the method in analysis of real sequences of data.

  13. Analysis of volatile organic compounds (VOCs) in A/M Area Crouch Branch (Cretaceous) Aquifer characterization samples: 1993

    Energy Technology Data Exchange (ETDEWEB)

    Looney, B.B.; Haselow, J.S.; Keenan, M.A.; Van Pelt, R.; Eddy-Dilek, C.A.; Rossabi, J.; Simmons, J.L.

    1993-12-06

    Samples were collected during the A/M Area Crouch Branch (Cretaceous) Aquifer Characterization (Phase I) Program. The samples were analyzed for chlorinated VOCs by the Savannah River Technology Center (SRTC) and MicroSeeps Ltd. All samples were sealed in the field immediately upon retrieval of the core and subsampling. A total of 113 samples locations were selected for analysis. The Environmental Sciences Section (ESS) of SRTC analyzed all locations in duplicate (226 samples). MicroSeeps Ltd was selected as the quality assurance (QA) check laboratory. MicroSeeps Ltd analyzed 40 locations with 4 duplicates (44 samples). The samples were collected from seven boreholes in A/M Area in the interval from 200 feet deep to the total depth of the boring (360 feet deep nominal); samples were collected every 10 feet within this interval. The sampling zone corresponds approximately to the Crouch Branch Aquifer in A/M Area. The overall A/M Area Crouch Branch Aquifer characterization objectives, a brief description of A/M Area geology and hydrology, and the sample locations, field notes, driller lithologic logs, and required procedural documentation are presented in WSRC (1993).

  14. Joint analysis and estimation of stock prices and trading volume in Barndorff-Nielsen and Shephard stochastic volatility models

    OpenAIRE

    Friedrich Hubalek; Petra Posedel

    2008-01-01

    We introduce a variant of the Barndorff-Nielsen and Shephard stochastic volatility model where the non Gaussian Ornstein-Uhlenbeck process describes some measure of trading intensity like trading volume or number of trades instead of unobservable instantaneous variance. We develop an explicit estimator based on martingale estimating functions in a bivariate model that is not a diffusion, but admits jumps. It is assumed that both the quantities are observed on a discrete grid of fixed width, a...

  15. Analysis of the high-temperature particulate collection problem

    Energy Technology Data Exchange (ETDEWEB)

    Razgaitis, R.

    1977-10-01

    Particulate agglomeration and separation at high temperatures and pressures are examined, with particular emphasis on the unique features of the direct-cycle application of fluidized-bed combustion. The basic long-range mechanisms of aerosol separation are examined, and the effects of high temperature and high pressure on usable collection techniques are assessed. Primary emphasis is placed on those avenues that are not currently attracting widespread research. The high-temperature, particulate-collection problem is surveyed, together with the peculiar requirements associated with operation of turbines with particulate-bearing gas streams. 238 references.

  16. Ultrasonic Nebulization Extraction Coupled with Gas Chromatography-Mass Spectrometry for Analysis of Volatile Components in Traditional Chinese Patent Medicine

    Institute of Scientific and Technical Information of China (English)

    LIANG Yue; WANG Lu; WANG Zi-ming; YU Cui; ZHANG Han-qi; SHI Yu-hua

    2011-01-01

    The ultrasonic nebulization extraction(UNE) was developed and applied to the extraction of volatile components from traditional Chinese patent medicine Xiaoyao Pills. Several parameters of ultrasonic nebulization extraction including the sample particle size, solvent volume, extraction time and ultrasonic power were studied and selected. As a result, 2.4 g of sample with particle size of 80 mesh was extracted with 15 mL of n-hexane for 20 min at an ultrasonic power of 35 W. The volatile components were analyzed by gas chromatography-mass spectrometry (GC-MS) under the optimal conditions and 57 compounds were identified. The precision, repeatability and stability of the proposed method were also studied. Compared with ultrasonic-assisted extraction(UAE) and hydrodistillation(HD) extraction, the proposed method is more efficient, faster and easier to be operated at room temperature with smaller sample and energy consumption. It is suggested that the ultrasonic nebulization extraction can be used as a novel alternative method for the extraction of volatile components from traditional Chinese patent medicine.

  17. Memory Analysis of the KBeast Linux Rootkit: Investigating Publicly Available Linux Rootkit Using the Volatility Memory Analysis Framework

    Science.gov (United States)

    2015-06-01

    on his computer system or network. Use of these tools and the analysis of virulent software always carry some inherent risk that must be securely...study of operating system internals and software reverse engineering techniques. Instead, this work should be considered as a guide to using the...employed throughout this text for the purpose of simplification . DRDC-RDDC-2015-R064 xi Availability of Linux memory images and profiles

  18. Security in NATO collective mission training - Problem analysis and solutions

    NARCIS (Netherlands)

    Möller, B.; Croom-Johnson, S.; Hartog, T.; Huiskamp, W.; Verkoelen, C.; Jones, G.; Bennett, M.

    2012-01-01

    We never fight alone, so we should train together! With missions being joint and combined, we also need to train that way. Given limited budgets and available resources, distributed simulation is rapidly becoming a necessity for collective mission training. However, due to the characteristics of mis

  19. Human glandular salivas : Their separate collection and analysis

    NARCIS (Netherlands)

    Veerman, ECI; vandenKeybus, PAM; Vissink, A; Amerongen, AVN

    1996-01-01

    Human saliva is secreted by the three pairs of major salivary glands (parotid, submandibular, and sublingual), and numerous minor ones, e.g. labial, buccal and (glosso)palatine glands. Using individually adapted collection devices, sublingual, submandibular, parotid and palatine secretions of five i

  20. Analysis of the hygroscopic and volatile properties of ammonium sulphate seeded and un-seeded SOA particles

    Directory of Open Access Journals (Sweden)

    N. K. Meyer

    2008-05-01

    Full Text Available The volatile and hygroscopic properties of ammonium sulphate seeded and un-seeded secondary organic aerosol (SOA derived from the photo-oxidation of atmospherically relevant concentrations of α-pinene were studied. The seed particles were electrospray generated ammonium sulphate ((NH42SO4 having diameters of approximately 33 nm with a quasi-mono-disperse size distribution (geometric standard deviation σg=1.3. The volatile and hygroscopic properties of both seeded and unseeded SOA were simultaneously measured with a VH-TDMA (volatility – hygroscopicity tandem differential mobility analyzer. VH-TDMA measurements of unseeded SOA show a decrease in the hygroscopic growth (HGF factor for increased volatilisation temperatures such that the more volatile compounds appear to be more hygroscopic. This is opposite to the expected preferential evaporation of more volatile but less hygroscopic material, but could also be due to enhanced oligomerisation occurring at the higher temperature in the thermodenuder. In addition, HGF measurements of seeded SOA were measured as a function of time at two relative humidities, below (RH 75% and above (RH 85% the deliquescence relative humidity (DRH of the pure ammonium sulphate seeds. As these measurements were conducted during the onset phase of photo-oxidation, during particle growth, they enabled us to find the dependence of the HGF as a function of the volume fraction of the SOA coating. HGF's measured at RH of 85% showed a continuous decrease as the SOA coating thickness increased. The measured growth factors show good agreements with ZSR predictions indicating that, at these RH values, there are only minor solute-solute interactions. At 75% RH, as the SOA fraction increased, a rapid increase in the HGF was observed indicating that an increasing fraction of the (NH42SO4 is subject to a phase transition, going into solution

  1. Analysis of Carbamate Pesticides: Validation of Semi-Volatile Analysis by HPLC-MS/MS by EPA Method MS666

    Energy Technology Data Exchange (ETDEWEB)

    Owens, J; Koester, C

    2008-05-14

    The Environmental Protection Agency's (EPA) Region 5 Chicago Regional Laboratory (CRL) developed a method for analysis of aldicarb, bromadiolone, carbofuran, oxamyl, and methomyl in water by high performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS), titled Method EPA MS666. This draft standard operating procedure (SOP) was distributed to multiple EPA laboratories and to Lawrence Livermore National Laboratory, which was tasked to serve as a reference laboratory for EPA's Environmental Reference Laboratory Network (ERLN) and to develop and validate analytical procedures. The primary objective of this study was to validate and verify the analytical procedures described in MS666 for analysis of carbamate pesticides in aqueous samples. The gathered data from this validation study will be used to: (1) demonstrate analytical method performance; (2) generate quality control acceptance criteria; and (3) revise the SOP to provide a validated method that would be available for use during a homeland security event. The data contained in this report will be compiled, by EPA CRL, with data generated by other EPA Regional laboratories so that performance metrics of Method EPA MS666 can be determined.

  2. Selection of adsorption traps for in situ gas chromatographic analysis of polar regolith volatiles on board of the Luna-Resource lander

    Science.gov (United States)

    Aseev, Sergey; Gerasimov, Mikhail; Zaitsev, Maxim

    Investigation of volatile species in the polar regions of the Moon is an important task for better understanding of its evolution and for further exploration, in particular, to provide resources for future permanent stations. Gas chromatographic complex of Space Research Institute of the Russian Academy of Science is focused on measurements of volatile compounds composition, supposedly existing in the polar regions of the Moon in the area of Luna-Resource probe landing (2017). Also, this devise can be used on the Mars in the area of ExoMars landing mission (2018). One of the features of this gas analytical system is the use of adsorption traps, which can retain volatile compounds continuously coming into the gas chromatograph as a result of pyrolysis of the regolith sample and shortly release them for injection into chromatographic system for analysis. To improve sensitivity and analytical properties of the gas chromatograph, it’s necessary to provide concentrated injection of all the volatile components, which were released during pyrolysis of the regolith sample. It takes ~15 minutes to complete this pyrolysis operation. Such permanent gases as noble gases and N2, Ar, CO on the left hand have low dynamic viscosity, which cause their short retention time in adsorption traps, but on the right hand - these gases are released from the soil sample close to the end of the heating cycle. Summarizing these principles, we can say that 5 minutes of trapping for specified gases is efficient enough for their accumulation with consequent heating of adsorption trap up to 150°C to produce concentrated injection of all these compounds to the analytical columns of gas chromatography system. In the most of space missions (Viking, Phoenix, MSL, Rosetta), which use gas chromatography as the main method for in situ chemical analysis of volatiles, chromatography columns are usually mounted in parallel scheme. It is well known that water has a negative influence on analytical

  3. Biological specimen collection and processing for molecular analysis.

    Science.gov (United States)

    Sanchez, Susan; Sellers, Holly

    2015-01-01

    This chapter provides a standardized best practice approach to sample collection and handling for the purpose of nucleic acid (NA) extraction and PCR. These methods are described through text and clearly illustrated figures. Furthermore, for those cases in which transportation of samples cannot be accomplished due to the inability to maintain the cold chain or limitations on the import of live disease agents in diagnostic samples, the chapter describes the use of FTA cards for collection transport and NA preparation of samples for PCR. This chapter also makes emphasis in the best safety practices for handling of samples/tissues to avoid unnecessary disease exposures to laboratory personnel. Finally, NA extraction best practices and methods will be briefly outlined.

  4. Volatility of an Indian stock market A random matrix approach

    CERN Document Server

    Kulkarni, V

    2005-01-01

    We examine volatility of an Indian stock market in terms of aspects like participation, synchronization of stocks and quantification of volatility using the random matrix approach. Volatility pattern of the market is found using the BSE index for the three-year period 2000-2002. Random matrix analysis is carried out using daily returns of 70 stocks for several time windows of 85 days in 2001 to (i) do a brief comparative analysis with statistics of eigenvalues and eigenvectors of the matrix C of correlations between price fluctuations, in time regimes of different volatilities. While a bulk of eigenvalues falls within RMT bounds in all the time periods, we see that the largest (deviating) eigenvalue correlates well with the volatility of the index, the corresponding eigenvector clearly shows a shift in the distribution of its components from volatile to less volatile periods and verifies the qualitative association between participation and volatility (ii) observe that the Inverse participation ratio for the ...

  5. Analysis of Cosmic Spherule Candidates from the Kwajalein Micrometeorite Collection

    Science.gov (United States)

    Wozniakiewicz, P. J.; Price, M. C.; Bradley, J. P.; Ishii, H. A.; Russell, S. S.; Zolensky, M. E.; Brownlee, D. E.

    2015-01-01

    The Kwajalein micrometeorite collection utilised high volume air samplers fitted with 5 micrometer laser-etched polycarbonate membrane filters to capture particles directly from the atmosphere. The filters were changed weekly over several months throughout 2011/12, providing the opportunity to investigate the contemporary flux of micrometeorites. We recently reported the results of our initial survey of cosmic spherule-like particles on several of these filters. We identified three main groups of particle based on bulk compositions: 1. Silicate spherules rich in Mg, Ca and Fe, 2. Silicate spherules rich in Al, Ca, K and/or Na and 3. Fe-rich spherules. Abundances appeared to change over time suggesting links with celestial activity (e.g. meteor showers), however, spherules similar to groups 2 and 3 can be produced by terrestrial and anthropogenic activity (e.g. volcanic microspherules exhibit similar compositions to group 2 spherules and metallic spherules similar to those of group 3 can be formed during fuel combustion). We are now studying the internal structures and chemistries of these spherules and comparing against cosmic spherules identified in other collections to confrim their origins and further contrain the contemporary micrometeorite flux. Particles are being picked, embedded in resin and polished through to reveal their interiors. Here we will describe our ongoing analyses of these particles via SEM. We will also introduce our new collection using this method that is currently being performed in the Antarctic.

  6. An Indirect Defence Trait Mediated through Egg-Induced Maize Volatiles from Neighbouring Plants.

    Directory of Open Access Journals (Sweden)

    Daniel M Mutyambai

    Full Text Available Attack of plants by herbivorous arthropods may result in considerable changes to the plant's chemical phenotype with respect to emission of herbivore-induced plant volatiles (HIPVs. These HIPVs have been shown to act as repellents to the attacking insects as well as attractants for the insects antagonistic to these herbivores. Plants can also respond to HIPV signals from other plants that warn them of impending attack. Recent investigations have shown that certain maize varieties are able to emit volatiles following stemborer egg deposition. These volatiles attract the herbivore's parasitoids and directly deter further oviposition. However, it was not known whether these oviposition-induced maize (Zea mays, L. volatiles can mediate chemical phenotypic changes in neighbouring unattacked maize plants. Therefore, this study sought to investigate the effect of oviposition-induced maize volatiles on intact neighbouring maize plants in 'Nyamula', a landrace known to respond to oviposition, and a standard commercial hybrid, HB515, that did not. Headspace volatile samples were collected from maize plants exposed to Chilo partellus (Swinhoe (Lepidoptera: Crambidae egg deposition and unoviposited neighbouring plants as well as from control plants kept away from the volatile emitting ones. Behavioural bioassays were carried out in a four-arm olfactometer using egg (Trichogramma bournieri Pintureau & Babault (Hymenoptera: Trichogrammatidae and larval (Cotesia sesamiae Cameron (Hymenoptera: Braconidae parasitoids. Coupled Gas Chromatography-Mass Spectrometry (GC-MS was used for volatile analysis. For the 'Nyamula' landrace, GC-MS analysis revealed HIPV production not only in the oviposited plants but also in neighbouring plants not exposed to insect eggs. Higher amounts of EAG-active biogenic volatiles such as (E-4,8-dimethyl-1,3,7-nonatriene were emitted from these plants compared to control plants. Subsequent behavioural assays with female T. bournieri and

  7. Geothermal Academy: Focus Center for Data Collection, Analysis, and Dissemination

    Energy Technology Data Exchange (ETDEWEB)

    Nakagawa, Masami, Ph.D.; Fujiono, Hendro, Ph.D.; McCartney, John S., Ph.D.; Reed, Adam, J.D., Esq.

    2011-10-31

    Geothermal Academy: A Pathway for Confirmation of Ground-Source Heat Pumps in the United States. In 2008, Oak Ridge National Laboratory issued a report on geothermal heats pumps (GHPs) focused on the market status, barriers to adoption, and actions to overcome these barriers (Hughes 2008). Of the barriers raised in this report, of the most pressing is the lack of performance and energy usage data for GHPs. Further, an associated barrier is a lack of a fair comparison of the energy usage of conventional heating and cooling systems for the same building. Because of these barriers, we are not able to say how much energy is used by well-designed GHP systems on a long-term basis, nor are we able to say how better their energy usage is compared to conventional systems. The need for a fair comparison with conventional systems is particularly relevant as modern versions of conventional air conditioners, gas furnaces, and boilers have also incorporated energy saving technologies. As a first step to address this barrier, the Geothermal Academy has developed a framework for data collection. This framework has already been applied to several geothermal installations in Colorado (Nakagawa etal. 2010). The framework classifies data into different categories based on the relevance of the dat to understanding the energy consumption of a GHP system. The categories are: direct energy consumption data, heat exchange performance data, and GHP design parameter data. The main recommendation of this project is to include a minimal data collection system on each heat pump installed in the U.S., capable of measuring the electrical energy consumed, the entering/exiting fluid temperatures, and circulation rates. This is a viable and cost effective solution which will provide performance data, as data collection systems are only a fraction of the cost of a GHP unit and modern GHP units already incorporate sensors to monitor energy usage and the entering and exiting fluid temperatures

  8. On the non-causal link between volatility and growth

    DEFF Research Database (Denmark)

    Posch, Olaf; Wälde, Klaus

    di er both in their volatility and growth. Using a continuous-time DSGE model with plausible parametric restrictions, we obtain closedform measures of macro volatility based on cyclical components and output growth rates. Given our results, empirical volatility-growth analysis should include controls...

  9. Implied volatility transmissions between Thai and selected advanced stock markets

    OpenAIRE

    Thakolsri, Supachok; Sethapramote, Yuthana; Jiranyakul, Komain

    2015-01-01

    This paper investigates the impacts of changes in the U. S. implied volatility on the changes in implied volatilities of the Euro and Thai stock markets. For that purpose, volatilities implicit in stock index option prices from the U. S., Euro and Thai stock markets are analyzed using the standard Granger causality test, impulse response analysis, and variance decompositions. The results found in this study suggest that the U. S. stock market is the leading source of volatility transmissions ...

  10. Analysis on Volatile Constituent in Pandan Leaves%香兰叶挥发性成分分析

    Institute of Scientific and Technical Information of China (English)

    任竹君; 王道平; 罗亚男; 陶晨

    2011-01-01

    [目的]检测香兰叶中挥发性成分.[方法]采用气相色谱-质谱联用仪(GC/MS)对香兰叶的挥发性成分进行了分析.[结果]鉴定出18种化学成分,其中含量最高的为亚油酸甲酯,其次为叶绿醇,还含有草蒿脑、棕榈酸、角鲨烯、甲基丁香酚,邻苯二甲酸、α-紫罗兰酮和吉马烯D等成分;另含有几种烷烃及少量的醛、酮类化合物.[结论]该方法准确、简便,适用于香兰叶中挥发性成分的检测.%[ Objective] The aim was to detect the volatile constituent in Pandan leaves. [ Method] The volatile constituent in Pandan leaves were analyzed using gas chromatography-mass spectrum. [Result] 18 kinds of chemical composition were identified, the content of linoleic acid methyl ester was highest, followed by phytol, and it also contained estragole, palmitic acid, squalene, methyl eugenol, phthalic acid, α-irisone and Gemmaen D. , in addition, it contained a small amount of several alkanes and aldehydes, ketones. [ Conclusion] The method is accurate, simple and convenient, is suitable to the detection of volatile constituent in Pandan leaves.

  11. Analysis of diffusion and adsorption of volatile organic compounds in zeolites by a single pellet moment technique

    Energy Technology Data Exchange (ETDEWEB)

    Akosman, Cevdet; Kalender, Mehmet [Department of Chemical Engineering, Firat University, Elazig (Turkey)

    2009-02-15

    The diffusion and adsorption of two common volatile organic compounds, i. e., methanol and benzene, in different zeolite pellets were studied experimentally by using the single pellet moment technique. The experiments were conducted in a one-sided single pellet adsorption cell at different temperatures in the range between 303 and 343 K. The results showed that both volatile organic tracers were adsorbed reversibly onto all zeolite samples. The overall adsorption equilibrium constants of both volatile organic compounds decreased with increasing temperature. The adsorption of the tracers onto the zeolite samples were found to increase in the order of NaY> clinoptilolite >4A. In the range between 303 and 343 K, the adsorption constants of benzene range from 10.51 to 5.52 for zeolite 4A, from 11.90 to 6.37 for clinoptilolite and from 20.32 to 9.82 for NaY. The adsorption constants of methanol range from 19.05 to 8.26 for zeolite 4A, from 38.40 to 9.12 for clinoptilolite and from 74.21 to 14.70 for NaY at temperatures between 303 and 333 K. The effective diffusivities for benzene varied from 2.20.10{sup -6} to 13.01.10{sup -6} m{sup 2}/s, whereas for methanol, they varied from 9.80.10{sup -6} to 15.60.10{sup -6} m{sup 2}/s at the temperatures studied. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

  12. 浒苔挥发性风味成分分析%Analysis of Volatile Flavor Compounds from Enteromorpha intestinalis

    Institute of Scientific and Technical Information of China (English)

    宋绍华; 裘迪红

    2012-01-01

    采用顶空固相微萃取-气质联用法对新鲜肠浒苔的挥发性风味成分进行测定,并加以感官评定分析比较风味物质组成。结果表明:浒苔的主要特征性风味物质是顺-3-十七烯,该物质在新鲜肠浒苔中含量高达59.54%,其次是棕榈醛、(E,E)-2,4-庚二烯醛、β-紫罗兰酮、壬醛、反式-2-己烯醛、2,4-戊二烯醛以及反,反-2,4-癸二烯醛等。%Headspace solid phase microextraction (HS-SPME) coupled with gas chromatography-mass spectrometer (GC-MS) was used to determine the volatile flavor compounds of the green macroalga Enteromorpha intestinalis. A comparative sensory evaluation of the main flavor substances was also done. The results showed that the main characteristic volatile flavor compound ofEnteromorpha intestinalis were (Z)-3-heptadecene, with a content as high as 59.43% in fresh samples. The other volatile flavors were hexadecanal, (E,E)-2,4-heptadienal, beta-ionone, nonanal, (E)-2-hexenal, 2,4 - pentadienal, (E,E)-2,4-decadienal, and so on.

  13. Dynamic headspace analysis of volatile metabolites from the reductive dehalogenation of trichloro- and tetrachloroethanes by hepatic microsomes.

    Science.gov (United States)

    Thompson, J A; Ho, B; Mastovich, S L

    1985-03-01

    A dynamic headspace technique was developed to facilitate the identification and quantitation of low levels of volatile metabolites produced in vitro by subcellular preparations. The method is complementary to commonly used static headspace and solvent-extraction techniques, and involves purging the compounds from microsomal suspensions with an inert gas, trapping them on a short column of adsorbant resin, and transferring the metabolites to a gas chromatograph. An apparatus was designed to facilitate the incubations and isolations of volatile compounds. Recoveries of several chlorinated hydrocarbons with boiling points in the range 12 to 186 degrees C were 85% or higher, and the recovery of vinyl chloride (boiling point -13 degrees C) was 25%. The quantitative precision of the method was determined and calibration curves were established for each metabolite, demonstrating that no discrimination occurred over a wide range of concentrations. This technique was employed to investigate the reductive metabolism of 1,1,1-trichloroethane, 1,1,2-trichloroethane, and 1,1,2,2-tetrachloroethane by rat liver microsomes. The metabolites from these substrates were 1,1-dichloroethane, vinyl chloride, and 1,2-dichloroethylene, respectively. These conversions were NADPH-dependent, occurred only under anaerobic conditions, and indicate that chloroethanes with relatively low electron affinities can be reduced slowly by microsomal cytochrome P-450. The rates of formation of vinyl chloride, 1,1-dichloroethane, and 1,2-dichloroethylene with 1.0 mM substrate were 12.5 +/- 2.0, 122 +/- 14, and 147 +/- 12 pmol/min/mg of protein, respectively. The results show that there are distinct advantages of the purge/trap method over the static headspace method for studying volatile metabolites when high sensitivity is required.

  14. 2-Nonenal-Ovulatory Specific Volatiles in Human Saliva throughout Menstrual Cycle by Gas Chromatography and Mass Spectrometry Analysis

    Directory of Open Access Journals (Sweden)

    S. Alagendran

    2010-01-01

    Full Text Available Problem statement: The present investigation carry out a pilot study of a novel method to identify the salivary volatiles in different phases of menstrual cycle for the assessment of ovulation detection using gas chromatography and mass spectrophotometer. Approach: The profiles from follicular phase (6-12 days; ovulatory phase (13-14 days and luteal phase (15-26 days of menstrual cycle samples were compared to establish any qualitative and quantitative differences that might have potential value in human olfactory communication. Dichloromethane was used as the solvent for extraction of the compounds. Results: Fifteen compounds were identified. They include organic compounds like, acid, aldehyde, amine and alcohol. The most important constituent was 2-nonenal, which usually comprised 75% or more of the total volatiles observed in ovulatory phase. The concentration of many constituents varied widely. This appeared to be periodically in three cycles for five of the constituents, with a period of a few weeks and with pronounced maxima at the peak of ovulatory period of which only two were common to all the chromatograms. The chemical profile of ovulatory phase saliva was distinguished by the presence of two specific compounds, viz. 2- Nonenal, Acetic acid and Acetaldehyde that were not found in the other reproductive phases of saliva sample in women. Apparently these compounds are 2-nonenal, dodecanol, acetic acid and acetaldehyde. One or more of these compounds may have pheromonal activity in human body odor. Conclusion: Differentiation of the volatile patterns among reproductive phases in women may help to find the diagnostic marker for ovulation detection.

  15. JAWS data collection, analysis highlights, and microburst statistics

    Science.gov (United States)

    Mccarthy, J.; Roberts, R.; Schreiber, W.

    1983-01-01

    Organization, equipment, and the current status of the Joint Airport Weather Studies project initiated in relation to the microburst phenomenon are summarized. Some data collection techniques and preliminary statistics on microburst events recorded by Doppler radar are discussed as well. Radar studies show that microbursts occur much more often than expected, with majority of the events being potentially dangerous to landing or departing aircraft. Seventy events were registered, with the differential velocities ranging from 10 to 48 m/s; headwind/tailwind velocity differentials over 20 m/s are considered seriously hazardous. It is noted that a correlation is yet to be established between the velocity differential and incoherent radar reflectivity.

  16. Analysis of volatile flavour compounds and acrylamide in roasted Malaysian tropical almond (Terminalia catappa) nuts using supercritical fluid extraction.

    Science.gov (United States)

    Lasekan, Ola; Abbas, Kassim

    2010-01-01

    Considering the importance of tropical almond nuts as a snack item, a study was conducted to identify the flavour volatiles and acrylamide generated during the roasting of the nuts. The supercritical fluid extracted flavour components revealed 74 aroma active compounds made up of 27 hydrocarbons, 12 aldehydes, 11 ketones, 7 acids, 4 esters, 3 alcohols, 5 furan derivatives a pyrazine, and 2 unknown compounds. While low levels of acrylamide (8-86 microg/kg) were obtained in the roasted nuts, significant (P0.05) concentration of acrylamide was generated with mild roasting and shorter roasting period.

  17. Development of solid-phase microextraction followed by gas chromatography-mass spectrometry for rapid analysis of volatile organic chemicals in mainstream cigarette smoke.

    Science.gov (United States)

    Ye, Qing

    2008-12-12

    In this work, a novel, simple and efficient method based on solid-phase microextraction (SPME) followed by gas chromatography-mass spectrometry (GC-MS) was developed to the analysis of volatile organic chemicals (VOCs) in mainstream cigarette smoke (MCS). Using a simple home-made smoking machine device, extraction and concentration of VOCs in MCS were performed by SPME fiber, and the VOCs adsorbed on fiber were desorbed, and analyzed by GC-MS. The extraction fiber types and the desorption conditions were studied, and the method precision was also investigated. After the investigation, the optimal fiber was divinylbenzene/carboxen/polydemethylsiloxane (DVB/CAR/PDMS), and the optimal desorption condition was 250 degrees C for 3 min. The method precision was from 2% to 11%. Finally, the proposed method was tested by its application of the analysis of VOCs in MCS from 10 brands of cigarettes and one reference cigarette. A total of 70 volatile compounds were identified by the proposed method. The experimental results showed that the proposed method was a simple, rapid, reliable, and solvent-free technique for the determination of VOCs in MCS.

  18. Analysis and quantitation of volatile organic compounds emitted from plastics used in museum construction by evolved gas analysis-gas chromatography-mass spectrometry.

    Science.gov (United States)

    Samide, Michael J; Smith, Gregory D

    2015-12-24

    Construction materials used in museums for the display, storage, and transportation of artwork must be assessed for their tendency to emit harmful pollution that could potentially damage cultural treasures. Traditionally, a subjective metals corrosion test known as the Oddy test has been widely utilized in museums for this purpose. To augment the Oddy test, an instrumental sampling approach based on evolved gas analysis (EGA) coupled to gas chromatography (GC) with mass spectral (MS) detection has been implemented for the first time to qualitatively identify off-gassed pollutants under specific conditions. This approach is compared to other instrumental methods reported in the literature. This novel application of the EGA sampling technique yields several benefits over traditional testing, including rapidity, high sensitivity, and broad detectability of volatile organic compounds (VOCs). Furthermore, unlike other reported instrumental approaches, the EGA method was used to determine quantitatively the amount of VOCs emitted by acetate resins and polyurethane foams under specific conditions using both an external calibration method as well as surrogate response factors. EGA was successfully employed to rapidly characterize emissions from 12 types of common plastics. This analysis is advocated as a rapid pre-screening method to rule out poorly performing materials prior to investing time and energy in Oddy testing. The approach is also useful for rapid, routine testing of construction materials previously vetted by traditional testing, but which may experience detrimental formulation changes over time. As an example, a case study on batch re-orders of rigid expanded poly(vinyl chloride) board stock is presented. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Reduced Heart Rate Volatility

    Science.gov (United States)

    Grogan, Eric L.; Morris, John A.; Norris, Patrick R.; France, Daniel J.; Ozdas, Asli; Stiles, Renée A.; Harris, Paul A.; Dawant, Benoit M.; Speroff, Theodore

    2004-01-01

    Objective: To determine if using dense data capture to measure heart rate volatility (standard deviation) measured in 5-minute intervals predicts death. Background: Fundamental approaches to assessing vital signs in the critically ill have changed little since the early 1900s. Our prior work in this area has demonstrated the utility of densely sampled data and, in particular, heart rate volatility over the entire patient stay, for predicting death and prolonged ventilation. Methods: Approximately 120 million heart rate data points were prospectively collected and archived from 1316 trauma ICU patients over 30 months. Data were sampled every 1 to 4 seconds, stored in a relational database, linked to outcome data, and de-identified. HR standard deviation was continuously computed over 5-minute intervals (CVRD, cardiac volatility–related dysfunction). Logistic regression models incorporating age and injury severity score were developed on a test set of patients (N = 923), and prospectively analyzed in a distinct validation set (N = 393) for the first 24 hours of ICU data. Results: Distribution of CVRD varied by survival in the test set. Prospective evaluation of the model in the validation set gave an area in the receiver operating curve of 0.81 with a sensitivity and specificity of 70.1 and 80.0, respectively. CVRD predict death as early as 24 hours in the validation set. Conclusions: CVRD identifies a subgroup of patients with a high probability of dying. Death is predicted within first 24 hours of stay. We hypothesize CVRD is a surrogate for autonomic nervous system dysfunction. PMID:15319726

  20. Evaluation of volatiles from two subtropical strawberry cultivars using GC-olfactometry, GC-MS odor activity values, and sensory analysis.

    Science.gov (United States)

    Du, Xiaofen; Plotto, Anne; Baldwin, Elizabeth; Rouseff, Russell

    2011-12-14

    Most strawberry flavor studies have examined berries grown in temperate regions with long summer days. Few studies have examined berries harvested in winter months from subtropical regions with shorter photoperiods. Fruits harvested in February and March from two strawberry cultivars, 'Strawberry Festival' and 'Florida Radiance', were examined. Thirty odor active compounds were detected using time-intensity GC-O. Twenty-nine were identified. The major odor active volatiles in both cultivars were 2,5-dimethyl-4-methoxy-3(2H)-furanone (DMMF), 2,5-dimethyl-4-hydroxy-3(2H)-furanone (DMHF), methyl butanoate, γ-decalactone, unknown (grassy, LRI 1362, wax), (E)-2-hexenal, linalool, (E,Z)-2,6-nonadienal, geraniol, butanoic acid, methyl 2-methylbutanoate, and ethyl hexanoate. Over 90 volatiles were identified and 54 quantified using GC-MS including 33 esters, 6 alcohols, 5 acids, 3 aldehydes, 3 lactones, 2 ketones, and 2 furanones. Odor activity values (OAVs) were determined for 46 volatiles, of which 22 had OAV > 1. The highest OAVs for 'Strawberry Festival' were ethyl butanoate (461), DMHF (424), methyl butanoate (358), and linalool (102). A 14-member trained panel evaluated quartered fruit using quantitative descriptive analysis to quantify seven sensory attributes. Sensory "strawberry flavor" scores were positively correlated with sensory "sweetness" (R(2) = 0.83) as well as GC-MS methyl 3-methylbutanoate (R(2) = 0.90) and ethyl butanoate (R(2) = 0.96). These cultivars lacked methyl anthranilate and possessed an aroma pattern different from summer-grown strawberries.

  1. 基于GARCH族模型的我国股市波动性分析%Analysis on the Volatility of Chinese Stock Market Based on GARCH Model

    Institute of Scientific and Technical Information of China (English)

    汤祥凤

    2016-01-01

    Taking Shanghai composite index and Shenzhen component index as the study obj ects,using GARCH class models of Shanghai and Shenzhen,the empirical analysis research has been carried on about volatility of asymmetry and volatility spillover effect,the empirical result shows that:(1)There is a sig-nificant role effect of the ARCH in the two cities,Shenzhen being at more risk on premium than in Shang-hai;(2 )There is a significant leverage effect showing a stronger fluctuation from bad news than good news in Shanghai and Shenzhen markets;(3)Both cities have one-way volatility spillover effect,and the fluctuations from Shanghai stock market can cause the fluctuations of Shenzhen.%以上证指数和深圳成指为研究对象,运用 GARCH 类模型对沪深两市的波动性、非对称性以及波动溢出效应进行了实证分析研究。实证表明:(1)两市存在显著的 ARCH 效应,且深市的风险溢价要高于沪市;(2)两市的杠杆效应较为显著,表明沪深市场上坏消息比好消息更能引起股市的剧烈波动;(3)两市存在单向的波动溢出效应,且沪市的波动会导致深市的波动。

  2. GC-MS Analysis of Volatile Components of Marsdenia tenacissima%GC-MS分析测定乌骨藤挥发性成分

    Institute of Scientific and Technical Information of China (English)

    李浡; 王晓杰; 李双石; 曹奇光; 谢国莉

    2012-01-01

    Objective: To study volatile components of Marsdenia tenocissima. Method; Soxhlet extraction method with petroleum ether and ethyl ether were accompanied with gas chromatography mass spectrometry (GC-MS) to analyze the volatile components respectively. Result; 24 compounds identified by GC-MS with petroleum ether accounted for 55. 43% of all volatile components; fatty acids were 75. 10% and alkanes were 11.91% ; 24 compounds identified with ethyl ether accounted for 60.43% ; fatty acids were 38.98% and alkanes were 39. 27% . Conclusion; The study provides useful data for further analysis of components of Marsdenia tenocissima.%目的:研究乌骨藤挥发性成分.方法:采用石油醚和乙醚作为溶剂,用索氏提取法提取挥发性成分,气相色谱-质谱联用技术(GC-MS)鉴定其化学成分.结果:采用石油醚作为溶剂鉴定出24种化合物,占挥发成分的55.43%,其中脂肪酸占75.10%,烷烃类占11.91%;乙醚作为溶剂提取鉴定出24种化合物,占60.43%,脂肪酸占38.98%,烷烃类占39.27%.结论:测定了乌骨藤挥发性成分,为进一步研究乌骨藤成分提供了理论依据.

  3. Realized volatility and absolute return volatility: a comparison indicating market risk.

    Science.gov (United States)

    Zheng, Zeyu; Qiao, Zhi; Takaishi, Tetsuya; Stanley, H Eugene; Li, Baowen

    2014-01-01

    Measuring volatility in financial markets is a primary challenge in the theory and practice of risk management and is essential when developing investment strategies. Although the vast literature on the topic describes many different models, two nonparametric measurements have emerged and received wide use over the past decade: realized volatility and absolute return volatility. The former is strongly favored in the financial sector and the latter by econophysicists. We examine the memory and clustering features of these two methods and find that both enable strong predictions. We compare the two in detail and find that although realized volatility has a better short-term effect that allows predictions of near-future market behavior, absolute return volatility is easier to calculate and, as a risk indicator, has approximately the same sensitivity as realized volatility. Our detailed empirical analysis yields valuable guidelines for both researchers and market participants because it provides a significantly clearer comparison of the strengths and weaknesses of the two methods.

  4. Storytelling: Discourse Analysis for Understanding Collective Perceptions of Medical Education

    Science.gov (United States)

    Vovides, Yianna; Inman, Sarah

    2013-01-01

    Using discourse analysis, the goal of this exploratory project was to determine what practitioners of medical education in Sub-Saharan Africa considered key achievements, within the scope of their Medical Education Partnership Initiative (MEPI) activities, after their initial two-year implementation efforts. To do so, a series of 58 video stories…

  5. Governmentally amplified output volatility

    Science.gov (United States)

    Funashima, Yoshito

    2016-11-01

    Predominant government behavior is decomposed by frequency into several periodic components: updating cycles of infrastructure, Kuznets cycles, fiscal policy over business cycles, and election cycles. Little is known, however, about the theoretical impact of such cyclical behavior in public finance on output fluctuations. Based on a standard neoclassical growth model, this study intends to examine the frequency at which public investment cycles are relevant to output fluctuations. We find an inverted U-shaped relationship between output volatility and length of cycle in public investment. This implies that periodic behavior in public investment at a certain frequency range can cause aggravated output resonance. Moreover, we present an empirical analysis to test the theoretical implication, using the U.S. data in the period from 1968 to 2015. The empirical results suggest that such resonance phenomena change from low to high frequency.

  6. Emerging Equity Market Volatility

    OpenAIRE

    Geert Bekaert; Harvey, Campbell R.

    1995-01-01

    Returns in emerging capital markets are very different from returns in developed markets. While most previous research has focused on average returns, we analyze the volatility of the returns in emerging equity markets. We characterize the time-series of volatility in emerging markets and explore the distributional foundations of the variance process. Of particular interest is evidence of asymmetries in volatility and the evolution of the variance process after periods of capital market refor...

  7. Volatility in Equilibrium

    DEFF Research Database (Denmark)

    Bollerslev, Tim; Sizova, Natalia; Tauchen, George

    Stock market volatility clusters in time, carries a risk premium, is fractionally inte- grated, and exhibits asymmetric leverage effects relative to returns. This paper develops a first internally consistent equilibrium based explanation for these longstanding empirical facts. The model is cast......, and the dynamic cross-correlations of the volatility measures with the returns calculated from actual high-frequency intra-day data on the S&P 500 aggregate market and VIX volatility indexes....

  8. 10491 Abstracts Collection -- Representation, Analysis and Visualization of Moving Objects

    OpenAIRE

    Sack, Jörg-Rüdiger; Speckmann, Bettina; Van Loon, Emiel; Weibel, Robert

    2011-01-01

    From December 5 to December 10, 2010, the Dagstuhl Seminar 10491 ``Representation, Analysis and Visualization of Moving Objects'' was held in Schloss Dagstuhl~--~Leibniz Center for Informatics. The major goal of this seminar has been to bring together the diverse and fast growing, research community that is involved in developing better computational techniques for spatio-temporal object representation, data mining, and visualization massive amounts of moving object data. ...

  9. Nuclear power and the public: analysis of collected survey research

    Energy Technology Data Exchange (ETDEWEB)

    Melber, B.D.; Nealey, S.M.; Hammersla, J.; Rankin, W.L.

    1977-11-01

    This executive summary highlights the major findings of a comprehensive synthesis and analysis of over 100 existing surveys dealing with public attitudes toward nuclear power issues. Questions of immediate policy relevance to the nuclear debate are posed and answered on the basis of these major findings. For each issue area, those sections of the report in which more-detailed discussion and presentation of relevant data may be found are indicated.

  10. Volatile organic metabolites identify patients with breast cancer, cyclomastopathy, and mammary gland fibroma.

    Science.gov (United States)

    Wang, Changsong; Sun, Bo; Guo, Lei; Wang, Xiaoyang; Ke, Chaofu; Liu, Shanshan; Zhao, Wei; Luo, Suqi; Guo, Zhigang; Zhang, Yang; Xu, Guowang; Li, Enyou

    2014-06-20

    The association between cancer and volatile organic metabolites in exhaled breaths has attracted increasing attention from researchers. The present study reports on a systematic study of gas profiles of metabolites in human exhaled breath by pattern recognition methods. Exhaled breath was collected from 85 patients with histologically confirmed breast disease (including 39 individuals with infiltrating ductal carcinoma, 25 individuals with cyclomastopathy and from 21 individuals with mammary gland fibroma) and 45 healthy volunteers. Principal component analysis and partial least squares discriminant analysis were used to process the final data. The volatile organic metabolites exhibited significant differences between breast cancer and normal controls, breast cancer and cyclomastopathy, and breast cancer and mammary gland fibroma; 21, 6, and 8 characteristic metabolites played decisive roles in sample classification, respectively (P fibroma patients, and patients with cyclomastopathy (P < 0.05). The identified three volatile organic metabolites associated with breast cancer may serve as novel diagnostic biomarkers.

  11. Bond Portfolio Analysis with Parallel Collections in Scala

    Directory of Open Access Journals (Sweden)

    Mark Logan

    2012-07-01

    Full Text Available In this paper, we report the results of new experiments that test the performance of Scala parallel collections to find the fair value of riskless bond portfolios using commodity multicore platforms. We developed four algorithms, each of two kinds in Scala and ran them for one to 1024 portfolios, each with a variable number of bonds with daily to yearly cash flows and 1 year to 30 year. We ran each algorithm 11 times at each workload size on three different multicore platforms. We systematically observed the differences and tested them for statistical significance. All the parallel algorithms exhibited super-linear speedup and super-efficiency consistent with maximum performance expectations for scientific computing workloads. The first-order effort or “naïve” parallel algorithms were easiest to write since they followed directly from the serial algorithms. We found we could improve upon the naïve approach with second-order efforts, namely, fine-grain parallel algorithms, which showed the overall best, statistically significant performance, followed by coarse-grain algorithms. To our knowledge these results have not been presented elsewhere.

  12. Chemical composition of volatile oils from leaves of Nectandra megapotamica Spreng. (Lauraceae)

    Energy Technology Data Exchange (ETDEWEB)

    Romoff, Paulete; Ferreira, Marcelo J.P., E-mail: romoff@mackenzie.b [Universidade Presbiteriana Mackenzie, Sao Paulo, SP (Brazil). Centro de Ciencias e Humanidades; Padilla, Ricardo; Toyama, Daniela O.; Favero, Oriana A. [Universidade Presbiteriana Mackenzie, Sao Paulo, SP (Brazil). Centro de Ciencias Biologicas e da Saude; Lago, Joao Henrique G. [Universidade Federal de Sao Paulo (UNIFESP), Diadema, SP (Brazil). Dept. de Ciencias Exatas e da Terra

    2010-07-01

    The volatile oils from Nectandra megapotamica Spreng. leaves, collected in February and August of 2007 and at 7:00 and 12:00 h (samples A - D), were extracted by hydrodistillation and the chemical composition was analyzed by GC-FID and GC/MS. A total of nineteen compounds were identified with predominance of oxygenated sesquiterpenes, among them, a-bisabolol, was the main constituent (62.3-69.4 %). After chromatographic separation procedures, this compound was purified from crude oil and its structure was confirmed by analysis of NMR data. This paper describes for the first time the composition of the leaves volatile oil from N. megapotamica. (author)

  13. VAPoR - Volatile Analysis by Pyrolysis of Regolith - an Instrument for In Situ Detection of Water, Noble Gases, and Organics on the Moon

    Science.gov (United States)

    ten Kate, I. L.; Cardiff, E. H.; Feng, S. H.; Holmes, V.; Malespin, C.; Stern, J. G.; Swindle, T. D.; Glavin, D. P.

    2010-01-01

    We present the Volatile Analysis by Pyrolysis of Regolith (VAPoR) instrument design and demonstrate the validity of an in situ pyrolysis mass spectrometer for evolved gas analyses of lunar and planetary regolith samples. In situ evolved gas analyses of the lunar regolith have not yet been carried out and no atmospheric or evolved gas measurements have been made at the lunar poles. VAPoR is designed to do both kinds of measurements, is currently under development at NASA's Goddard Space Flight Center, and will be able to heat powdered regolith samples or rock drill fines up to 1400 C in vacuo. To validate the instrument concept, evolved gas species released from different planetary analogs were determined as a function of temperature using a laboratory breadboard. Evolved gas measurements of an Apollo 16 regolith sample and a fragment of the carbonaceous meteorite Murchison were made by VAPoR and our results compared with existing data. The results imply that in situ evolved gas measurements of the lunar regolith at the polar regions by VAPoR will be a very powerful tool for identifying water and other volatile signatures of lunar or exogenous origin as potential resources for future human exploration.

  14. Identification, synthesis, and characterization of novel sulfur-containing volatile compounds from the in-depth analysis of Lisbon lemon peels (Citrus limon L. Burm. f. cv. Lisbon).

    Science.gov (United States)

    Cannon, Robert J; Kazimierski, Arkadiusz; Curto, Nicole L; Li, Jing; Trinnaman, Laurence; Jańczuk, Adam J; Agyemang, David; Da Costa, Neil C; Chen, Michael Z

    2015-02-25

    Lemons (Citrus limon) are a desirable citrus fruit grown and used globally in a wide range of applications. The main constituents of this sour-tasting fruit have been well quantitated and characterized. However, additional research is still necessary to better understand the trace volatile compounds that may contribute to the overall aroma of the fruit. In this study, Lisbon lemons (C. limon L. Burm. f. cv. Lisbon) were purchased from a grove in California, USA, and extracted by liquid-liquid extraction. Fractionation and multidimensional gas chromatography-mass spectrometry were utilized to separate, focus, and enhance unidentified compounds. In addition, these methods were employed to more accurately assign flavor dilution factors by aroma extract dilution analysis. Numerous compounds were identified for the first time in lemons, including a series of branched aliphatic aldehydes and several novel sulfur-containing structures. Rarely reported in citrus peels, sulfur compounds are known to contribute significantly to the aroma profile of the fruit and were found to be aroma-active in this particular study on lemons. This paper discusses the identification, synthesis, and organoleptic properties of these novel volatile sulfur compounds.

  15. Critical role of a pre-purge setup in the thermal desorption analysis of volatile organic compounds by gas chromatography with mass spectrometry.

    Science.gov (United States)

    Kim, Yong-Hyun; Kim, Ki-Hyun

    2015-07-01

    In general, volatile organic compounds in ambient air are quantified by following a well-defined standard calibration procedure using a gas-/liquid-phase standard. If the liquid standard is analyzed by a thermal desorption, the solvent effect is unavoidable through the alteration of breakthrough properties or retention times. To learn more about the variables of the thermal desorption-based analysis, the effect of pre-purge conditions was evaluated for 18 volatile organic compounds with different types of sorbent tube materials by fixing standard volume (1 μL) and flow rate (100 mL/min). The gas phase calibration was also carried out as reference for the non-solvent effect. A single tube filled with Tenax TA exhibited the least solvent effect with the short pre-purge (1 min), while being subject to the breakthrough at or above 10 min pre-purge. For a three-bed sorbent tube with Carboxen 1000, at least 10 min of pre-purge was needed for the compounds with a retention time close to methanol (e.g., propanal). Another three-bed tube with Carbopack X reduced the solvent effect efficiently for a short pre-purge (2 min) without the breakthrough. As such, the solvent effect can be adjusted by the proper control of the sorbent tube application.

  16. Integrated Data Collection Analysis (IDCA) Program — Quarterly Review Meeting

    Energy Technology Data Exchange (ETDEWEB)

    Sandstrom, Mary M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Brown, Geoffrey W. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Warner, Kirstin F. [Naval Surface Warfare Center (IHD-NSWC), Indian Head, MD (United States). Indian Head Division; Sorensen, Daniel N. [Naval Surface Warfare Center (IHD-NSWC), Indian Head, MD (United States). Indian Head Division; Remmers, Daniel L. [Naval Surface Warfare Center (IHD-NSWC), Indian Head, MD (United States). Indian Head Division; Shelley, Timothy J. [Air Force Research Lab. (AFRL/RXQF), Tyndall AFB, FL (United States); Reyes, Jose A. [Applied Research Associates, Inc., Tyndall AFB, FL (United States); Phillips, Jason J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Hsu, Peter C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Reynolds, John G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2011-12-05

    On November 9 and 10, 2011 the IDCA had the annual quarterly meeting. The meeting started the afternoon of the first day with a tour of the NSWC IHD explosives safety testing and analysis facilities. The meeting on the second day addressed the formal sponsor review and further technical issues for the IDCA. Examination of the IHD equipment during the tour, lead to a long discussion on liquid test methods. The discussion resulted in revision of liquid test methods in the impact test and selection of a new liquid test standard. In addition, modifications to friction, spark and thermal test methods were discussed.

  17. Development of an affordable data collection, reporting, and analysis system.

    Science.gov (United States)

    Howard, William R

    2003-02-01

    Available professionally designed systems for recording, storing, retrieving, and analyzing patient data (such as treatments delivered, laboratory and pulmonary function test results, ventilator settings, and patient assessments) are prohibitively expensive to many hospitals and clinics. At Tufts-New England Medical Center we designed and implemented a computerized patient data management system that uses relatively inexpensive "personal digital assistants" and inexpensive, commonly-available software. Compared to the pen-and-paper flow sheet system we previously used, our computerized system saves time and money, is accurate and user-friendly, and allows data retrieval and analysis that can improve clinical practice and efficiency. We believe our experience could benefit other institutions.

  18. CFD analysis of heat collection in a glazed gallery

    Energy Technology Data Exchange (ETDEWEB)

    Suarez, Maria Jose; Gutierrez, Antonio Jose; Pistono, Jorge; Blanco, Eduardo [Universidad de Oviedo, EDZE (Energia), Campus de Viesques, 33271 Gijon, Asturias (Spain)

    2011-01-15

    A glazed gallery in most old buildings is a space located on the first floor (and/or higher floors), facing south and almost fully glazed. As a result of the large glazed area and the orientation of the gallery, its temperature is warmer than the exterior and, in cold weather, it is used both as a space to insulate the adjacent rooms and as a leisure area, among other applications. In the framework of the ARFRISOL project (Bioclimatic Architecture and Solar Cooling), a demonstration container has been constructed in northern Spain (Asturias) which includes, among other bioclimatic elements, a glazed gallery. This gallery is considered as an element of Bioclimatic Architecture that enables solar radiation to be collected and the energy obtained to be used to support the building's air conditioning system. It consists of a south-facing glazed exterior wall, an intermediate space or passage and a partially glazed interior wall. Dampers located in the floor and ceiling of the intermediate space and connected to the air ducts enable the air circulating inside the gallery to be heated or cooled, depending on the season of the year, before it is further conditioned and conveyed to the rooms. This paper focuses on the three-dimensional numerical simulation of the airflow inside the gallery. The aim is to obtain a model to evaluate the thermal energy obtained in this architectural feature, integrating the effect of certain variables, such as the incident solar irradiation, the outdoor temperature and the air flow rate circulating in the gallery. (author)

  19. Optimization of volatile fatty acids and hydrogen production from Saccharina japonica: acidogenesis and molecular analysis of the resulting microbial communities.

    Science.gov (United States)

    Jung, Kwonsu; Kim, Woong; Park, Gwon Woo; Seo, Charles; Chang, Ho Nam; Kim, Yeu-Chun

    2015-04-01

    Response surface methodology (RSM) was used to optimize the production of volatile fatty acids (VFAs) and hydrogen from mixed anaerobic cultures of Saccharina japonica with respect to two independent variables: methanogenic inhibitor concentration and temperature. The effects of four methanogenic inhibitors on acidogenic processes were tested, and qualitative microbial analyses were carried out. Escherichia, Acinetobacter, and Clostridium were the most predominant genera in samples treated with chloroform (CHCl3), iodoform (CHI3), 2-bromoethanesulfonate (BES), or β-cyclodextrin (β-CD), respectively. RSM showed that the production of VFAs reached a peak of 12.5 g/L at 38.6 °C in the presence of 7.4 g/L β-CD; these were the conditions under which hydrogen production was also nearly maximal. The quantitative polymerase chain reaction (qPCR) showed that shifts in the bacterial community population correlated with the concentrations of β-CD indicating that this compound effectively inhibited methanogens.

  20. Multi-trait analysis of post-harvest storage in rocket salad (Diplotaxis tenuifolia) links sensorial, volatile and nutritional data.

    Science.gov (United States)

    Spadafora, Natasha D; Amaro, Ana L; Pereira, Maria J; Müller, Carsten T; Pintado, Manuela; Rogers, Hilary J

    2016-11-15

    Rocket salad (Diplotaxis tenuifolia; wild rocket) is an important component of ready to eat salads providing a distinct peppery flavour and containing nutritionally relevant compounds. Quality deteriorates during post-harvest, in relation to time and storage temperature amongst other factors. Volatile organic compounds (VOCs) are easily measurable from rocket leaves and may provide useful quality indicators for e.g. changes in isothiocyanates derived from nutritionally important glucosinolates. VOC profiles discriminated storage temperatures (0, 5 and 10°C) and times (over 14days). More specifically, concentrations of aldehydes and isothiocyanates decreased with time paralleling a fall in vitamin C and a reduction in sensorial quality at the two higher temperatures. Sulphur containing compounds rise at later time-points and at higher temperatures coincident with an increase in microbial titre, mirroring a further drop in sensorial quality thus indicating their contribution to off-odours.

  1. Time-resolved analysis of primary volatile emissions and secondary aerosol formation potential from a small-scale pellet boiler

    Science.gov (United States)

    Czech, Hendryk; Pieber, Simone M.; Tiitta, Petri; Sippula, Olli; Kortelainen, Miika; Lamberg, Heikki; Grigonyte, Julija; Streibel, Thorsten; Prévôt, André S. H.; Jokiniemi, Jorma; Zimmermann, Ralf

    2017-06-01

    Small-scale pellet boilers and stoves became popular as a wood combustion appliance for domestic heating in Europe, North America and Asia due to economic and environmental aspects. Therefore, an increasing contribution of pellet boilers to air pollution is expected despite their general high combustion efficiency. As emissions of primary organic aerosol (POA) and permanent gases of pellet boilers are well investigated, the scope of this study was to investigate the volatile organic emissions and the formation potential of secondary aerosols for this type of appliance. Fresh and aged emissions were analysed by a soot-particle aerosol time-of-flight mass spectrometry (SP-AMS) and the molecular composition of the volatile precursors with single-photon ionisation time-of-flight mass spectrometry (SPI-TOFMS) at different pellet boiler operation conditions. Organic emissions in the gas phase were dominated by unsaturated hydrocarbons while wood-specific VOCs, e.g. phenolic species or substituted furans, were only detected during the starting phase. Furthermore, organic emissions in the gas phase were found to correlate with fuel grade and combustion technology in terms of secondary air supply. Secondary organic aerosols of optimised pellet boiler conditions (OPT, state-of-the-art combustion appliance) and reduced secondary air supply (RSA, used as a proxy for pellet boilers of older type) were studied by simulating atmospheric ageing in a Potential Aerosol Mass (PAM) flow reactor. Different increases in OA mass (55% for OPT, 102% for RSA), associated with higher average carbon oxidation state and O:C, could be observed in a PAM chamber experiment. Finally, it was found that derived SOA yields and emission factors were distinctly lower than reported for log wood stoves.

  2. Visualization and Analysis of Frames in Collections of Messages: Content Analysis and the Measurement of Meaning

    CERN Document Server

    Vlieger, Esther

    2011-01-01

    A step-to-step introduction is provided on how to generate a semantic map from a collection of messages (full texts, paragraphs or statements) using freely available software and/or SPSS for the relevant statistics and the visualization. The techniques are discussed in the various theoretical contexts of (i) linguistics (e.g., Latent Semantic Analysis), (ii) sociocybernetics and social systems theory (e.g., the communication of meaning), and (iii) communication studies (e.g., framing and agenda-setting). We distinguish between the communication of information in the network space (social network analysis) and the communication of meaning in the vector space. The vector space can be considered a generated as an architecture by the network of relations in the network space; words are then not only related, but also positioned. These positions are expected rather than observed and therefore one can communicate meaning. Knowledge can be generated when these meanings can recursively be communicated and therefore a...

  3. Developing a Value of Information (VoI) Enabled System from Collection to Analysis

    Science.gov (United States)

    2016-11-01

    Analysis by Mark R Mittrick, John T Richardson, Alex Vertlieb, and Timothy P Hanratty Approved for public release...US Army Research Laboratory Developing a Value of Information (VoI)- Enabled System from Collection to Analysis by Mark R Mittrick, John...Developing a Value of Information (VoI)-Enabled System from Collection to Analysis 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT

  4. Understanding evolution of product composition and volatility distribution through in-situ GC × GC analysis: a case study of longifolene ozonolysis

    Directory of Open Access Journals (Sweden)

    N. M. Donahue

    2011-06-01

    Full Text Available A method for predicting volatility and polarity based on chromatographic information was developed and applied to the smog chamber ozonolysis of the sesquiterpene longifolene. The products were collected and analyzed using a GC × GC Thermal Desorption Aerosol Gas Chromatograph/Mass Spectrometer (2D-TAG and a quadrupole Aerodyne Aerosol Mass Spectrometer (AMS. All the secondary organic aerosol (SOA was produced within the first half hour of the experiment. However, the oxidation level of the organic aerosol, as inferred from the fraction of ion m/z 44, suggested continued evolution of the SOA over the subsequent hours. Measurements of speciated organic compounds using 2D-TAG confirm that the composition of the particles changed over the course of the experiment. Nearly 200 oxidation products (thought to be mostly ketones and acids were observed with 2D-TAG, but most could not be identified definitively due to a lack of standards and the absence of likely sesquiterpene oxidation products in available mass spectral databases. To categorize the observed products, the vapor pressure and oxygen-to-carbon ratio (O/C of observed compounds were estimated based on their two-dimensional chromatographic retention times relative to those of known standards, establishing a retention time correlation (RTC method for using 2D-TAG to better constrain important modelling parameters. The product distribution continuously evolved in volatility and oxygenation during 5 h of oxidation. Using peak area as the best available proxy for mass, we conclude that the product mixture includes many non-negligible products; the most abundant 3 compounds accounted for only half of the total observed peak area and 80 % of peak area was spread across 15 compounds. The data provide evidence for three conclusions: (1 2D-TAG provides valuable volatility and oxygenation information even in the absence of definitive species identification, (2 complex particle-phase chemistry causes

  5. Understanding evolution of product composition and volatility distribution through in situ GC × GC analysis: a case study of longifolene ozonolysis

    Directory of Open Access Journals (Sweden)

    N. M. Donahue

    2011-01-01

    Full Text Available A method for predicting volatility and polarity based on chromatographic information was developed and applied to the smog chamber ozonolysis of the sesquiterpene longifolene. The products were collected and analyzed using a GC × GC Thermal Desorption Aerosol Gas Chromatograph/Mass Spectrometer (2D-TAG and a quadrupole Aerodyne Aerosol Mass Spectrometer (AMS. All the secondary organic aerosol (SOA was produced within the first half hour of the experiment. However, the oxidation level of the organic aerosol, as inferred from the fraction of ion m/z 44, suggested continued evolution of the SOA over the subsequent hours. Measurements of speciated organic compounds using 2D-TAG confirm that the composition of the particles changed over the course of the experiment. Nearly 200 oxidation products (thought to be mostly ketones and acids were observed with 2D-TAG, but most could not be identified definitively due to a lack of standards and the absence of likely sesquiterpene oxidation products in available mass spectral databases. To categorize the observed products, the vapor pressure and oxygen-to-carbon ratio (O/C of observed compounds were estimated based on their multi-dimensional chromatographic retention times relative to those of known standards, establishing a retention time correlation (RTC method for using 2D-TAG to better constrain important modelling parameters. The product distribution continuously evolved in volatility and oxygenation during 5 h of oxidation. Using peak area as the best available proxy for mass, we conclude that the product mixture includes many non-negligible products; the most abundant 3 compounds accounted for only half of the total observed peak area and 80% of peak area was spread across 15 compounds. The data provide evidence for three conclusions: (1 2D-TAG can provide valuable volatility and oxygenation information even in the absence of definitive species identification, (2 complex particle-phase chemistry

  6. Flower volatiles, crop varieties and bee responses.

    Directory of Open Access Journals (Sweden)

    Björn K Klatt

    Full Text Available Pollination contributes to an estimated one third of global food production, through both the improvement of the yield and the quality of crops. Volatile compounds emitted by crop flowers mediate plant-pollinator interactions, but differences between crop varieties are still little explored. We investigated whether the visitation of crop flowers is determined by variety-specific flower volatiles using strawberry varieties (Fragaria x ananassa Duchesne and how this affects the pollination services of the wild bee Osmia bicornis L. Flower volatile compounds of three strawberry varieties were measured via headspace collection. Gas chromatography showed that the three strawberry varieties produced the same volatile compounds but with quantitative differences of the total amount of volatiles and between distinct compounds. Electroantennographic recordings showed that inexperienced females of Osmia bicornis had higher antennal responses to all volatile compounds than to controls of air and paraffin oil, however responses differed between compounds. The variety Sonata was found to emit a total higher level of volatiles and also higher levels of most of the compounds that evoked antennal responses compared with the other varieties Honeoye and Darselect. Sonata also received more flower visits from Osmia bicornis females under field conditions, compared with Honeoye. Our results suggest that differences in the emission of flower volatile compounds among strawberry varieties mediate their attractiveness to females of Osmia bicornis. Since quality and quantity of marketable fruits depend on optimal pollination, a better understanding of the role of flower volatiles in crop production is required and should be considered more closely in crop-variety breeding.

  7. ANALYSIS ON CYCLONE COLLECTION EFFICIENCIES AT HIGH TEMPERATURES

    Institute of Scientific and Technical Information of China (English)

    Jianyi Chen; Mingxian Shi

    2003-01-01

    In order to predict the influence of operating temperature on cyclone performance, an experimental investigation on particle separation was conducted in a 300 mm diameter, tangential volute-inlet and reverse flow cyclone separator with air heated up to 973 K. The test powder silica has a mean mass diameter of 10 microns and the measured as a function of the inlet velocity and operating temperature. It is shown that at the same inlet velocity both the overall efficiency and fractional efficiency decrease with an increase of temperature. An analysis of our own data and published results has shown that the fractional efficiency of a cyclone is a definite function of such dimensionless numbers as Stokes number, Reynolds number, Froude number and dimensionless cyclone inlet area and dimensionless outlet diameter. A nondimensional experimental correlation of the cyclone performance, including the influence of the temperature, was obtained on the basis of our own previous work. The prediction of the influence of temperature on separation efficiencies is in fairly good agreement with experimental results.

  8. Simultaneous analysis of 22 volatile organic compounds in cigarette smoke using gas sampling bags for high-throughput solid-phase microextraction.

    Science.gov (United States)

    Sampson, Maureen M; Chambers, David M; Pazo, Daniel Y; Moliere, Fallon; Blount, Benjamin C; Watson, Clifford H

    2014-07-15

    Quantifying volatile organic compounds (VOCs) in cigarette smoke is necessary to establish smoke-related exposure estimates and evaluate emerging products and potential reduced-exposure products. In response to this need, we developed an automated, multi-VOC quantification method for machine-generated, mainstream cigarette smoke using solid-phase microextraction gas chromatography-mass spectrometry (SPME-GC-MS). This method was developed to simultaneously quantify a broad range of smoke VOCs (i.e., carbonyls and volatiles, which historically have been measured by separate assays) for large exposure assessment studies. Our approach collects and maintains vapor-phase smoke in a gas sampling bag, where it is homogenized with isotopically labeled analogue internal standards and sampled using gas-phase SPME. High throughput is achieved by SPME automation using a CTC Analytics platform and custom bag tray. This method has successfully quantified 22 structurally diverse VOCs (e.g., benzene and associated monoaromatics, aldehydes and ketones, furans, acrylonitrile, 1,3-butadiene, vinyl chloride, and nitromethane) in the microgram range in mainstream smoke from 1R5F and 3R4F research cigarettes smoked under ISO (Cambridge Filter or FTC) and Intense (Health Canada or Canadian Intense) conditions. Our results are comparable to previous studies with few exceptions. Method accuracy was evaluated with third-party reference samples (≤15% error). Short-term diffusion losses from the gas sampling bag were minimal, with a 10% decrease in absolute response after 24 h. For most analytes, research cigarette inter- and intrarun precisions were ≤20% relative standard deviation (RSD). This method provides an accurate and robust means to quantify VOCs in cigarette smoke spanning a range of yields that is sufficient to characterize smoke exposure estimates.

  9. A gap analysis methodology for collecting crop genepools: a case study with phaseolus beans.

    Directory of Open Access Journals (Sweden)

    Julián Ramírez-Villegas

    Full Text Available BACKGROUND: The wild relatives of crops represent a major source of valuable traits for crop improvement. These resources are threatened by habitat destruction, land use changes, and other factors, requiring their urgent collection and long-term availability for research and breeding from ex situ collections. We propose a method to identify gaps in ex situ collections (i.e. gap analysis of crop wild relatives as a means to guide efficient and effective collecting activities. METHODOLOGY/PRINCIPAL FINDINGS: The methodology prioritizes among taxa based on a combination of sampling, geographic, and environmental gaps. We apply the gap analysis methodology to wild taxa of the Phaseolus genepool. Of 85 taxa, 48 (56.5% are assigned high priority for collecting due to lack of, or under-representation, in genebanks, 17 taxa are given medium priority for collecting, 15 low priority, and 5 species are assessed as adequately represented in ex situ collections. Gap "hotspots", representing priority target areas for collecting, are concentrated in central Mexico, although the narrow endemic nature of a suite of priority species adds a number of specific additional regions to spatial collecting priorities. CONCLUSIONS/SIGNIFICANCE: Results of the gap analysis method mostly align very well with expert opinion of gaps in ex situ collections, with only a few exceptions. A more detailed prioritization of taxa and geographic areas for collection can be achieved by including in the analysis predictive threat factors, such as climate change or habitat destruction, or by adding additional prioritization filters, such as the degree of relatedness to cultivated species (i.e. ease of use in crop breeding. Furthermore, results for multiple crop genepools may be overlaid, which would allow a global analysis of gaps in ex situ collections of the world's plant genetic resources.

  10. 迷迭香挥发油提取工艺优化及其化学成分分析%Optimization of Extraction Technology of Volatile Oil from Rosemary and Analysis on the Chemical Constituents of Volatile Oil

    Institute of Scientific and Technical Information of China (English)

    黄宏妙; 郭占京; 卢汝梅; 蒙亮

    2012-01-01

    Volatile oil was extracted from rosemary (Rosmarinus officinalis L.) by water steam distillation method. The extraction technology was optimized by orthogonal test. And the chemical constituents of volatile oil in fresh and dry rosemary were compared by GC-MS. According to orthogonal design, the optimum technology for extracting volatile oil from rosemary was, the herb was cut into pieces with length of 1 cm, then soaked for 3 h when the dosage of water was fifteen fold of material mass, and extracted for 4 h, under such conditions the extraction rate of volatile oil was 1.870%. And the chemical constituents of volatile oil in fresh and dry rosemary were similar. The quality was not affected by drying in the shade.%采用水蒸气蒸馏法提取迷迭香(Rosmarinus officindis L.)挥发油,运用正交设计优化提取工艺.结果表明,迷迭香挥发油最佳提取工艺条件为迷迭香剪成1 cm长的小段、料水质量比1∶15、浸泡时间3h、提取时间4h,此条件下挥发油的得率为1.870%.运用GC-MS技术分析并比较了迷迭香鲜样和干样挥发油的化学成分,结果表明二者化学成分基本相同,药材阴干后挥发油品质没有受到明显影响.

  11. Understanding Financial Market Volatility

    NARCIS (Netherlands)

    A. Opschoor (Anne)

    2014-01-01

    markdownabstract__Abstract__ Volatility has been one of the most active and successful areas of research in time series econometrics and economic forecasting in recent decades. Loosely speaking, volatility is defined as the average magnitude of fluctuations observed in some phenomenon over time. Wi

  12. Improving Garch Volatility Forecasts

    NARCIS (Netherlands)

    Klaassen, F.J.G.M.

    1998-01-01

    Many researchers use GARCH models to generate volatility forecasts. We show, however, that such forecasts are too variable. To correct for this, we extend the GARCH model by distinguishing two regimes with different volatility levels. GARCH effects are allowed within each regime, so that our model

  13. Understanding Financial Market Volatility

    NARCIS (Netherlands)

    A. Opschoor (Anne)

    2014-01-01

    markdownabstract__Abstract__ Volatility has been one of the most active and successful areas of research in time series econometrics and economic forecasting in recent decades. Loosely speaking, volatility is defined as the average magnitude of fluctuations observed in some phenomenon over

  14. Volatile metabolites from actinomycetes

    DEFF Research Database (Denmark)

    Scholler, C.E.G.; Gurtler, H.; Pedersen, R.

    2002-01-01

    Twenty-six Streptomyces spp. were screened for their volatile production capacity on yeast starch agar. The volatile organic compounds (VOCs) were concentrated on a porous polymer throughout an 8-day growth period. VOCs were analyzed by gas chromatography with flame ionization detection and ident...

  15. Modelling of volatility in monetary transmission mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Dobešová, Anna; Klepáč, Václav; Kolman, Pavel [Department of Statistics and Operation Analysis, Faculty of Business and Economics, Mendel University in Brno, Zemědělská 1, 61300, Brno (Czech Republic); Bednářová, Petra [Institute of Technology and Business, Okružní 517/10, 370 01, České Budějovice (Czech Republic)

    2015-03-10

    The aim of this paper is to compare different approaches to modeling of volatility in monetary transmission mechanism. For this purpose we built time-varying parameter VAR (TVP-VAR) model with stochastic volatility and VAR-DCC-GARCH model with conditional variance. The data from three European countries are included in the analysis: the Czech Republic, Germany and Slovakia. Results show that VAR-DCC-GARCH system captures higher volatility of observed variables but main trends and detected breaks are generally identical in both approaches.

  16. Dynamic headspace analyses of residual volatiles in pharmaceuticals.

    Science.gov (United States)

    Wampler, T P; Bowe, W A; Levy, E J

    1985-02-01

    Pharmaceutical preparations may be assayed for volatile organic compounds by purging them with a stream of inert carrier gas and collecting the organics onto a suitable sorbent material, from which they may be backflushed to a gas chromatograph. Compared to solvent extraction, the process offers advantages of increased sensitivity, ease of automation, and elimination of the solvent peak. Examples are given of three major sources of volatiles in pharmaceuticals, with the development of a method for quantitating the volatiles using an internal standard.

  17. Comparison of natural and roasted Turkish tombul hazelnut (Corylus avellana L.) volatiles and flavor by DHA/GC/MS and descriptive sensory analysis.

    Science.gov (United States)

    Alasalvar, Cesarettin; Shahidi, Fereidoon; Cadwallader, Keith R

    2003-08-13

    Natural (raw) and roasted hazelnuts were compared for their differences in volatile components and sensory responses. A total of 79 compounds were detected in both hazelnuts, of which 39 (27 positive, 5 tentative, and 7 unknown) were detected in natural hazelnut and 71 (40 positive, 14 tentative, and 17 unknown) were detected in roasted hazelnut. These included ketones, aldehydes, pyrazines, alcohols, aromatic hydrocarbons, furans, pyrroles, terpenes, and acids. Pyrazines, pyrroles, terpenes, and acids were detected in roasted hazelnut only. Concentrations of several compounds increased as a result of roasting and these may play significant roles in the flavor of roasted hazelnut. Pyrazines together with ketones, aldehydes, furans, and pyrroles may contribute to the characteristic roasted aroma of hazelnut. Descriptive sensory analysis (DSA) showed that some flavor attributes such as "aftertaste", "burnt", "coffee/chocolate-like", "roasty", and "sweet" were rated significantly higher in roasted hazelnut compared to its natural counterpart. Natural and roasted hazelnuts can be distinguished using these attributes.

  18. Determination of geosmin, 2-methylisoborneol, and a musty-earthy odor in wheat grain by SPME-GC-MS, profiling volatiles, and sensory analysis.

    Science.gov (United States)

    Jeleń, Henryk H; Majcher, Małgorzata; Zawirska-Wojtasiak, Renata; Wiewiórowska, Małgorzata; Wasowicz, Erwin

    2003-11-19

    Geosmin and 2-methylisoborneol-compounds responsible for the musty-earthy off-odor of wheat grain, were isolated by SPME and analyzed by GC-MS. Carboxen/PDMS/DVB fiber coating was selected because of its highest extraction efficiency. Concentrations of geosmin and 2-methylisoborneol as low as 0.001 microg/kg were detected in SIM mode using ion trap mass spectrometer. Apart from GC-MS determination of geosmin and 2-methylisoborneol, various methods for evaluating the musty-earthy off-odor caused by these compounds in wheat grain are presented. Sensory profile analysis differentiated wheat grain into sound and off-flavored, but the method was tedious. Similar groupings, however, were obtained using more rapid methods such as comparison of volatile profiles using SPME-fast GC with PCA projection of data and metal oxide (MOS) based electronic nose.

  19. Qualitative and quantitative analysis of a group of volatile organic compounds in biological samples by HS-GC/FID: application in practical cases.

    Science.gov (United States)

    Monteiro, C; Franco, J M; Proença, P; Castañera, A; Claro, A; Vieira, D N; Corte-Real, F

    2014-10-01

    A simple and sensitive procedure, using n-propanol as internal standard (IS), was developed and validated for the qualitative and quantitative analysis of a group of 11 volatile organic substances with different physicochemical properties (1-butanol, 2-propanol, acetaldehyde, ethyl acetate, acetone, acetonitrile, chloroform, diethyl ether, methanol, toluene and p-xylene) in whole blood, urine and vitreous humor. Samples were prepared by dilution with an aqueous solution of internal standard followed by Headspace Gas Chromatography with a Flame-ionization Detector (HS GC-FID) analysis. Chromatographic separation was performed using two capillary columns with different polarities (DB-ALC2: 30m×0.320mm×1.2μm and DB-ALC1: 30m×0.320mm×1.8μm), thus providing a change in the retention and elution order of volatiles. This dual column confirmation increases the specificity, since the risk of another substance co-eluting at the same time in both columns is very small. The method was linear from 5 to 1000mg/L for toluene and p-xylene, 50-1000mg/L for chloroform, and 50-2000mg/L for the remaining substances, with correlation coefficients of over 0.99 for all compounds. The limits of detection (LOD) ranged 1 to 10mg/L, while the limits of quantification (LOQ) ranged from 2 to 31mg/L. The intra-day precision (CV<6.4%), intermediate precision (CV<7.0%) and accuracy (relative error ±10%) of the method were in conformity with the criteria normally accepted in bioanalytical method validation. The method developed has been applied to forensic cases, with the advantages that it uses a small sample volume and does not require any extraction procedure as it makes use of a headspace injection technique.

  20. 皱叶薄荷精油的化学分类特征%Analysis on Chemotype of Volatile Oil of Mentha crispata Schrad. ex Willd

    Institute of Scientific and Technical Information of China (English)

    郭晓恒; 刘涛; 宋登敏; 雨田; 严铸云

    2014-01-01

    This study was aimed to analyze the volatile oil of Mentha crispata Schrad. ex Willd. in order to provide evidence for its chemotype and guidance for its production application. The chemical analysis was detected by headspace GC-MS. The results showed that 64 chemical compounds were detected. It was concluded that the volatile oil of M. crispata Schrad. ex Willd. mainly contained eucalyptol (35.58%), limonene (16.92%) and pinene (15.33%). It was concluded that the analysis on composition characteristics and main compounds of M. crispata Schrad. ex Willd. can provide evidences in its production application and chemotype.%目的:对皱叶薄荷精油进行成分分析,为种源鉴定提供化学分类依据并为生产应用提供指导。方法:采用顶空气相法对皱叶薄荷全草进行化学分析。结果:共得到64个化学成分,且皱叶薄荷主要由桉油素(Eucalyptol ,35.58%)、柠檬烯(Limonene ,16.92%)及蒎烯(Pinene ,15.33%)组成。结论:通过分析皱叶薄荷精油的组成特征及主要成分,可为其生产应用及种源鉴定提供化学分类佐证。

  1. Soil Samplers: New Techniques for Subsurface Sampling for Volatile Organic Compounds

    Energy Technology Data Exchange (ETDEWEB)

    Susan Sorini; John Schabron; Joseph Rovani; Mark Sanderson

    2009-03-31

    Soil sampling techniques for volatile organic analysis must be designed to minimize loss of volatile organic compounds (VOCs) from the soil that is being sampled. Preventing VOC loss from soil cores that are collected from the subsurface and brought to the surface for subsampling is often difficult. Subsurface bulk sample retrieval systems are designed to obtain intact cylindrical cores of soil ranging anywhere from one to four inches in diameter, and one to several feet in length. The current technique that is used to subsample these soil cores for VOC analysis is to expose a horizontal section of the soil core to the atmosphere; screen the exposed soil using a photoionization detector (PID) or other appropriate device to locate contamination in the soil core; and use a hand-operated coring tool to collect samples from the exposed soil for analysis. Because the soil core can be exposed to the atmosphere for a considerable length of time during screening and sample collection, the current sub-sampling technique provides opportunity for VOCs to be lost from the soil. This report describes three alternative techniques from the current technique for screening and collecting soil samples from subsurface soil cores for VOC analysis and field testing that has been done to evaluate the techniques. Based on the results of the field testing, ASTM D4547, Standard Guide for Sampling Waste and Soils for Volatile Organic Compounds, was revised to include information about the new techniques.

  2. The analysis of collective mindsets: introducing a new method of institutional analysis in comparative research

    Directory of Open Access Journals (Sweden)

    Markus Pohlmann

    2014-12-01

    Full Text Available This article presents a specific qualitative method - the Collective Mindset Analysis (CMA - that is applicable within the frame of institutional analysis to map the cognitive and normative institutions at work. The purpose of this paper is to introduce and discuss the method and its methodology as well. The paper will elaborate on how the method is applied to international research and will provide concrete examples drawn from a bigger research project on economic elites in eleven countries. It will demonstrate the steps of interpretation of interview material from this project with the help of CMA, using concrete text sequences. The sequences have been extracted from interviews with Brazilian top managers that were conducted in the context of an international research project. The paper will show, how an institutional approach, that is relying on the sociology of knowledge, can be supported by a method, that helps to reconstruct the cognitive and normative rules in a given culture and to analyze, how these rules are translated in action orientations to solve culturally significant problems. Thus, the method can be a remedy for the shortcomings of institutional analysis in mapping and comparing the knowledge stocks in different cultures and a new tool in international comparative research.

  3. 10 CFR 707.12 - Specimen collection, handling and laboratory analysis for drug testing.

    Science.gov (United States)

    2010-01-01

    ... drug testing. 707.12 Section 707.12 Energy DEPARTMENT OF ENERGY WORKPLACE SUBSTANCE ABUSE PROGRAMS AT DOE SITES Procedures § 707.12 Specimen collection, handling and laboratory analysis for drug testing... collection to final disposition of specimens, and testing laboratories shall use appropriate cutoff levels in...

  4. 78 FR 31568 - Proposed Collection; 60-day Comment Request: Autism Spectrum Disorder Research Portfolio Analysis

    Science.gov (United States)

    2013-05-24

    ... Collection; 60-day Comment Request: Autism Spectrum Disorder Research Portfolio Analysis SUMMARY: In... be submitted to the Office of Management and Budget (OMB) for review and approval. Written comments... Information: To obtain a copy of the data collection plans and instruments, submit comments in writing,...

  5. Clustered Stomates in "Begonia": An Exercise in Data Collection & Statistical Analysis of Biological Space

    Science.gov (United States)

    Lau, Joann M.; Korn, Robert W.

    2007-01-01

    In this article, the authors present a laboratory exercise in data collection and statistical analysis in biological space using clustered stomates on leaves of "Begonia" plants. The exercise can be done in middle school classes by students making their own slides and seeing imprints of cells, or at the high school level through collecting data of…

  6. Human skin volatiles: a review.

    Science.gov (United States)

    Dormont, Laurent; Bessière, Jean-Marie; Cohuet, Anna

    2013-05-01

    Odors emitted by human skin are of great interest to biologists in many fields; applications range from forensic studies to diagnostic tools, the design of perfumes and deodorants, and the ecology of blood-sucking insect vectors of human disease. Numerous studies have investigated the chemical composition of skin odors, and various sampling methods have been used for this purpose. The literature shows that the chemical profile of skin volatiles varies greatly among studies, and the use of different sampling procedures is probably responsible for some of these variations. To our knowledge, this is the first review focused on human skin volatile compounds. We detail the different sampling techniques, each with its own set of advantages and disadvantages, which have been used for the collection of skin odors from different parts of the human body. We present the main skin volatile compounds found in these studies, with particular emphasis on the most frequently studied body regions, axillae, hands, and feet. We propose future directions for promising experimental studies on odors from human skin, particularly in relation to the chemical ecology of blood-sucking insects.

  7. Analysis of beer volatiles by polymeric imidazolium-solid phase microextraction coatings: Synthesis and characterization of polymeric imidazolium ionic liquids.

    Science.gov (United States)

    González-Álvarez, Jaime; Blanco-Gomis, Domingo; Arias-Abrodo, Pilar; Pello-Palma, Jairo; Ríos-Lombardía, Nicolás; Busto, Eduardo; Gotor-Fernández, Vicente; Gutiérrez-Álvarez, María Dolores

    2013-08-30

    Two polymeric ionic liquids, 3-(but-3″-en-1″-yl)-1-[2'-hydroxycyclohexyl]-1H-imidazol-3-ium bis(trifluoromethanesulfonyl)imide (IL-1) and 1-(2'-hydroxycyclohexyl)-3-(4″-vinylbenzyl)-1H-imidazol-3-ium bis(trifluoromethylsulfonyl)imide (IL-2), have been synthesized by a free radical polymerization reaction and used as coatings for solid-phase microextraction (SPME). These new fibers exhibit good film stability, high thermal stability (270-290°C) and long lifetimes, and are used for the extraction of volatile compounds in lemon beer using gas chromatography separation and flame ionization detection. The scanning electron micrographs of the fiber surface revealed a polymeric ionic liquid (PIL) film, which is distributed homogeneously on the fiber. The developed PIL fiber showed good linearity between 50 and 2000μg/L with regression coefficients in the range of 0.996-0.999. The relative standard deviations (RSD) obtained in the peak area were found to vary between 1% and 12%, which assured that adequate repeatability was achieved. The spiked recoveries for three beer samples ranged from 78.4% to 123.6%. Experimental design has been employed in the optimization of extraction factors and robustness assessment. The polymeric IL-1 butenyl fiber showed a greater efficiency compared to the PDMS-DVB (65μm) and CAR-PDMS (75μm) for the extraction of all of the analytes studied.

  8. Nanoparticle-Incorporated PDMS Film as an Improved Performance SPME Fiber for Analysis of Volatile Components of Eucalyptus Leaf

    Directory of Open Access Journals (Sweden)

    Parviz Aberoomand Azar

    2013-01-01

    Full Text Available A new fabrication strategy was proposed to prepare polydimethylsiloxane (PDMS- coated solid-phase microextraction (SPME on inexpensive and unbreakable Cu fiber. PDMS was covalently bonded to the Cu substrate using self-assembled monolayer (SAM of (3-mercaptopropyltrimethoxysilane (3MPTS as binder. To increase the performance of the fiber, the incorporation effect of some nanomaterials including silica nanoparticles (NPs, carbon nanotubes (CNTs, and carboxylated carbon nanotubes (CNT-COOH to PDMS coating was compared. The surface morphology of the prepared fibers was characterized by scanning electron microscopy (SEM, and their applicability was evaluated through the extraction of some volatile organic compounds (VOCs of Eucalyptus leaf in headspace mode, and parameters affecting the extraction efficiency including extraction temperature and extraction time were optimized. Extracted compounds were analyzed by GC-MS instrument. The results obtained indicated that prepared fibers have some advantages relative to previously prepared SPME fibers, such as higher thermal stability and improved performance of the fiber. Also, results showed that SPME is a fast, simple, quick, and sensitive technique for sampling and sample introduction of Eucalyptus VOCs.

  9. Volatile organic compounds (VOCs) in urban air: How chemistry affects the interpretation of positive matrix factorization (PMF) analysis

    Science.gov (United States)

    Yuan, Bin; Shao, Min; de Gouw, Joost; Parrish, David D.; Lu, Sihua; Wang, Ming; Zeng, Limin; Zhang, Qian; Song, Yu; Zhang, Jianbo; Hu, Min

    2012-12-01

    Volatile organic compounds (VOCs) were measured online at an urban site in Beijing in August-September 2010. Diurnal variations of various VOC species indicate that VOCs concentrations were influenced by photochemical removal with OH radicals for reactive species and secondary formation for oxygenated VOCs (OVOCs). A photochemical age-based parameterization method was applied to characterize VOCs chemistry. A large part of the variability in concentrations of both hydrocarbons and OVOCs was explained by this method. The determined emission ratios of hydrocarbons to acetylene agreed within a factor of two between 2005 and 2010 measurements. However, large differences were found for emission ratios of some alkanes and C8 aromatics between Beijing and northeastern United States secondary formation from anthropogenic VOCs generally contributed higher percentages to concentrations of reactive aldehydes than those of inert ketones and alcohols. Anthropogenic primary emissions accounted for the majority of ketones and alcohols concentrations. Positive matrix factorization (PMF) was also used to identify emission sources from this VOCs data set. The four resolved factors were three anthropogenic factors and a biogenic factor. However, the anthropogenic factors are attributed here to a common source at different stages of photochemical processing rather than three independent sources. Anthropogenic and biogenic sources of VOCs concentrations were not separated completely in PMF. This study indicates that photochemistry of VOCs in the atmosphere complicates the information about separated sources that can be extracted from PMF and the influence of photochemical processing must be carefully considered in the interpretation of source apportionment studies based upon PMF.

  10. Needle-type extraction device for the purge and trap analysis of 23 volatile organic compounds in tap water.

    Science.gov (United States)

    Ueta, Ikuo; Razak, Nurhafizza Abd; Mizuguchi, Ayako; Kawakubo, Susumu; Saito, Yoshihiro; Jinno, Kiyokatsu

    2013-11-22

    We developed a rapid determination technique for trace volatile organic compounds (VOCs) in tap water by introducing a novel needle-type extraction device coupled to a purge-and-trap method. To extract a wide range of VOCs, a new extraction needle containing particles of divinylbenzene and activated carbon was developed in this study. During the active sampling of the headspace gas in a glass vial by the extraction needle, pure N2 gas was used for purging the aqueous sample. After the optimization of several experimental parameters, such as the addition of the salt and conditions of dry purging and desorption, the extraction performance of the device and method was evaluated for 23 VOCs that are typically found in tap water samples. The quantification limits of the method were 0.6 μg/L for 1,1-dichloroethylene and less than 0.5 μg/L for other VOCs, with good repeatability being confirmed for all the target compounds. Taking advantage of the excellent recovery of VOCs, the determination of VOCs in real tap water samples was carried out successfully. Because the developed method does not require sample heating and/or cryogenic focusing, simple and rapid analyses can be performed along with satisfactory sensitivity for typical tap water samples.

  11. NVL-C: Static Analysis Techniques for Efficient, Correct Programming of Non-Volatile Main Memory Systems

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seyong [ORNL; Vetter, Jeffrey S [ORNL

    2016-01-01

    Computer architecture experts expect that non-volatile memory (NVM) hierarchies will play a more significant role in future systems including mobile, enterprise, and HPC architectures. With this expectation in mind, we present NVL-C: a novel programming system that facilitates the efficient and correct programming of NVM main memory systems. The NVL-C programming abstraction extends C with a small set of intuitive language features that target NVM main memory, and can be combined directly with traditional C memory model features for DRAM. We have designed these new features to enable compiler analyses and run-time checks that can improve performance and guard against a number of subtle programming errors, which, when left uncorrected, can corrupt NVM-stored data. Moreover, to enable recovery of data across application or system failures, these NVL-C features include a flexible directive for specifying NVM transactions. So that our implementation might be extended to other compiler front ends and languages, the majority of our compiler analyses are implemented in an extended version of LLVM's intermediate representation (LLVM IR). We evaluate NVL-C on a number of applications to show its flexibility, performance, and correctness.

  12. In vivo analysis of palm wine (Elaeis guineensis) volatile organic compounds (VOCs) by proton transfer reaction-mass spectrometry

    Science.gov (United States)

    Lasekan, Ola; Otto, Sabine

    2009-04-01

    The in vivo volatile organic compounds (VOCs) release patterns in palm wine was carried out using the PTR-MS. In order to analyze the complex mixtures of VOCs in palm wine, the fragmentation patterns of 14 known aroma compounds of palm wine were also investigated. Results revealed masses m/z (43, 47, 61, 65, 75, 89 and 93) as the predominant ones measured in-breathe exhaled from the nose, during consumption of palm wine. Further studies of aroma's fragmentation patterns, showed that the m/z 43 is characteristic of fragment of various compounds, while m/z 47 is ethanol, m/z 61(acetic acid), m/z 65 (protonated ethanol cluster ions), m/z 75 (methyl acetate), m/z 89 (acetoin) and m/z 93 (2-phenylethanol) respectively. The dynamic release parameters (Imax and tmax) of the 7 masses revealed significant (P = 0.05) differences, between maximum intensity (Imax) and no significant (P = 0.05) differences between tmax among VOCs respectively.

  13. Grain-size analysis of sediment cores collected in 2009 offshore from Palos Verdes, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of the data release includes grain-size analysis of sediment cores collected in 2009 offshore of Palos Verdes, California. It is one of seven files...

  14. 77 FR 45717 - Proposed Information Collection (Food Service and Nutritional Care Analysis) Activity; Comment...

    Science.gov (United States)

    2012-08-01

    ... to determine patients' satisfaction with the quality of food and nutrition services. DATES: Written... level of patient satisfaction and quality of service resulting from advanced food preparation and... Information Collection (Food Service and Nutritional Care Analysis) Activity; Comment Request AGENCY:...

  15. Method for Determining Language Objectives and Criteria. Volume II. Methodological Tools: Computer Analysis, Data Collection Instruments.

    Science.gov (United States)

    1979-05-25

    This volume presents (1) Methods for computer and hand analysis of numerical language performance data (includes examples) (2) samples of interview, observation, and survey instruments used in collecting language data. (Author)

  16. GC/MS Analysis of Volatile Components of Echinacea Species%不同紫锥花种属中挥发性组分的气相色谱/质谱分析

    Institute of Scientific and Technical Information of China (English)

    姚兴东; 聂园梅; Nirmalendu Datta-Gupta

    2004-01-01

    The volatile constituents of three Echinacea species are investigated with GC/MS analysis of their ethanol extracts. The results show different Echinacea species have different constituents; the volatile parts may also have contribution to the medicinal effect of herb.%通过气相色谱/质谱联用技术分析了三种常见紫锥花种属E. Angustifolia, E. Pallida和 E. Purpurea中挥发性组分.从结果分析,这些挥发性组分对于其药效也有部分贡献.

  17. Fast analysis of volatile components of Achillea tenuifolia Lam with microwave distillation followed by headspace single-drop microextraction coupled to gas chromatography-mass spectrometry (GC-MS).

    Science.gov (United States)

    Piryaei, Marzieh; Nazemiyeh, Hossein

    2016-01-01

    This article investigates the effect of microwaves on the amount of volatile compounds Achillea tenuifolia Lam with two methods, headspace single-drop microextraction and microwave-assisted headspace single-drop microextraction (MA-SDME), for the analysis of essential oil. Solvent selection, solvent volume, microwave power, irradiation time and sample mass were optimised by the simplex method.

  18. Modeling and Forecasting the Volatility of Eastern European Emerging Markets

    Directory of Open Access Journals (Sweden)

    Sang Hoon Kang

    2009-06-01

    Full Text Available This study has attempted to seek a volatility forecasting model that can reflect sufficiently the long memory characteristic in the volatility of four Eastern European emerging stock markets, naThis study has attempted to seek a volatility forecasting model that can reflect sufficiently the long memory characteristic in the volatility of four Eastern European emerging stock markets, namely, Hungary, Poland, Russia, and Slovakia. From the results of our empirical analysis, we found that the FIGARCH model is better equipped to capture the long memory property in the volatility of these markets than the GARCH and IGARCH models. More importantly, the FIGARCH model is found to provide superior performance in one-day-ahead volatility forecasts. Thus, this study recommends researchers, portfolio managers, and traders to use the long memory FIGARCH model in analyzing and forecasting the volatility dynamics of Eastern European emerging markets.

  19. Multivariate analysis of the volatile components in tobacco based on infrared-assisted extraction coupled to headspace solid-phase microextraction and gas chromatography-mass spectrometry.

    Science.gov (United States)

    Yang, Yanqin; Pan, Yuanjiang; Zhou, Guojun; Chu, Guohai; Jiang, Jian; Yuan, Kailong; Xia, Qian; Cheng, Changhe

    2016-11-01

    A novel infrared-assisted extraction coupled to headspace solid-phase microextraction followed by gas chromatography with mass spectrometry method has been developed for the rapid determination of the volatile components in tobacco. The optimal extraction conditions for maximizing the extraction efficiency were as follows: 65 μm polydimethylsiloxane-divinylbenzene fiber, extraction time of 20 min, infrared power of 175 W, and distance between the infrared lamp and the headspace vial of 2 cm. Under the optimum conditions, 50 components were found to exist in all ten tobacco samples from different geographical origins. Compared with conventional water-bath heating and nonheating extraction methods, the extraction efficiency of infrared-assisted extraction was greatly improved. Furthermore, multivariate analysis including principal component analysis, hierarchical cluster analysis, and similarity analysis were performed to evaluate the chemical information of these samples and divided them into three classifications, including rich, moderate, and fresh flavors. The above-mentioned classification results were consistent with the sensory evaluation, which was pivotal and meaningful for tobacco discrimination. As a simple, fast, cost-effective, and highly efficient method, the infrared-assisted extraction coupled to headspace solid-phase microextraction technique is powerful and promising for distinguishing the geographical origins of the tobacco samples coupled to suitable chemometrics.

  20. Analyzing blends of herbivore-induced volatile organic compounds with factor analysis: revisiting "cotton plant, Gossypium hirsutum L., defense in response to nitrogen fertilization".

    Science.gov (United States)

    Chen, Yigen

    2013-04-01

    Many herbivorous, predaceous, and parasitic insects use constitutive and herbivore-induced volatile organic compounds (VOCs) to locate their respective host plant, prey, and hosts. Multivariate statistical tools (e.g., factor analysis) are recognized increasingly as an appropriate approach for analyzing intercorrelated data such as presence/absence or quantities of VOCs. One challenge of implementing factor analysis is determining how many new variables (factors) to retain in the final analysis. I demonstrate a method proposed by Johnson and Wichern to mitigate this problem by using VOC data published in Chen et al. The advantage of using loading (or weight) transformation in interpretation of new variables was also illustrated in the example. Factor analysis found similar nitrogen fertilization effects on VOC production as those in Chen et al. Similarities were 1) nitrogen fertilization interacted with herbivore damage status on VOC production: at low nitrogen (42 ppm) level, beet armyworm, Spodoptera exigua (Hübner) (Lepidoptera: Noctuidae), damage elicited increases in VOC production, whereas at high nitrogen (196 ppm) VOC production was suppressed; 2) nitrogen fertilization did not affect limonene, alpha-pinene, and beta-pinene production. The seven individual VOCs significantly affected by nitrogen fertilization in Chen et al. were (Z)-3-hexenal, (E)-2-hexenal, (E)-beta-farnesene, (E)-4,8-dimethyl-1,3,7-nonatriene (DMNT), alpha-bergamotene, gamma-bisabolene, and bisabolol, of which only three ((E)-beta-farnesene, gamma-bisabolene, and bisabolol) weighed heavily on factor 1 in the current study.

  1. Integrated Data Collection Analysis (IDCA) Program - Statistical Analysis of RDX Standard Data Sets

    Energy Technology Data Exchange (ETDEWEB)

    Sandstrom, Mary M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Brown, Geoffrey W. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Preston, Daniel N. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Pollard, Colin J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Warner, Kirstin F. [Naval Surface Warfare Center (NSWC), Indian Head, MD (United States). Indian Head Division; Sorensen, Daniel N. [Naval Surface Warfare Center (NSWC), Indian Head, MD (United States). Indian Head Division; Remmers, Daniel L. [Naval Surface Warfare Center (NSWC), Indian Head, MD (United States). Indian Head Division; Phillips, Jason J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Shelley, Timothy J. [Air Force Research Lab. (AFRL), Tyndall AFB, FL (United States); Reyes, Jose A. [Applied Research Associates, Tyndall AFB, FL (United States); Hsu, Peter C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Reynolds, John G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-10-30

    The Integrated Data Collection Analysis (IDCA) program is conducting a Proficiency Test for Small- Scale Safety and Thermal (SSST) testing of homemade explosives (HMEs). Described here are statistical analyses of the results for impact, friction, electrostatic discharge, and differential scanning calorimetry analysis of the RDX Type II Class 5 standard. The material was tested as a well-characterized standard several times during the proficiency study to assess differences among participants and the range of results that may arise for well-behaved explosive materials. The analyses show that there are detectable differences among the results from IDCA participants. While these differences are statistically significant, most of them can be disregarded for comparison purposes to assess potential variability when laboratories attempt to measure identical samples using methods assumed to be nominally the same. The results presented in this report include the average sensitivity results for the IDCA participants and the ranges of values obtained. The ranges represent variation about the mean values of the tests of between 26% and 42%. The magnitude of this variation is attributed to differences in operator, method, and environment as well as the use of different instruments that are also of varying age. The results appear to be a good representation of the broader safety testing community based on the range of methods, instruments, and environments included in the IDCA Proficiency Test.

  2. Analysis of Volatile Compounds in Galangal%中药材良姜挥发性组分分析

    Institute of Scientific and Technical Information of China (English)

    赵亭亭; 李霞; 李磊; 张昭良

    2012-01-01

    通过顶空固相微萃取结合气-质联用技术,分析检测中药良姜的挥发性组分,研究萃取时间、萃取温度对良姜挥发性物质数量的影响.结果表明,当萃取时间为35 min,萃取温度为60℃时共检出53种化学组分,其中52种物质可鉴别.其主要组分是萜烯类化合物(w =40.238%)、桉树脑(w=23.066%)、α-松油醇(w=8.522%)、β-蒎烯(w=3.618%)和莰烯(w=3.001%)等.%Headspace solid phase micro-extraction coupling with gas chromatography-mass spectrometry ( HS-SPME/GC-MS) was used to analyze volatile compounds of galangal. Effect of extraction time and temperature on the amount of identified compounds was discussed under the optimal SPME conditions :35 min extraction time,60 ℃ extraction temperature. 53 kinds of compounds were separated by the gas chromatography and 52 kinds of these can be determined under certain conditions above with the results as follows; the main component was terpenes (40. 238% ) , and other compounds of high content were eucalyptol ( 23. 066% ) , p-menth-1 -en-8-ol (8.522% ) ,β-pinene (3.618% ) .camphene (3.001% ) ,and so on.

  3. Improvement of a headspace solid phase microextraction-gas chromatography/mass spectrometry method for the analysis of wheat bread volatile compounds.

    Science.gov (United States)

    Raffo, Antonio; Carcea, Marina; Castagna, Claudia; Magrì, Andrea

    2015-08-07

    An improved method based on headspace solid phase microextraction combined with gas chromatography-mass spectrometry (HS-SPME/GC-MS) was proposed for the semi-quantitative determination of wheat bread volatile compounds isolated from both whole slice and crust samples. A DVB/CAR/PDMS fibre was used to extract volatiles from the headspace of a bread powdered sample dispersed in a sodium chloride (20%) aqueous solution and kept for 60min at 50°C under controlled stirring. Thirty-nine out of all the extracted volatiles were fully identified, whereas for 95 other volatiles a tentative identification was proposed, to give a complete as possible profile of wheat bread volatile compounds. The use of an array of ten structurally and physicochemically similar internal standards allowed to markedly improve method precision with respect to previous HS-SPME/GC-MS methods for bread volatiles. Good linearity of the method was verified for a selection of volatiles from several chemical groups by calibration with matrix-matched extraction solutions. This simple, rapid, precise and sensitive method could represent a valuable tool to obtain semi-quantitative information when investigating the influence of technological factors on volatiles formation in wheat bread and other bakery products.

  4. Characterisation of calamansi (Citrus microcarpa). Part II: volatiles, physicochemical properties and non-volatiles in the juice.

    Science.gov (United States)

    Cheong, Mun Wai; Zhu, Danping; Sng, Jingting; Liu, Shao Quan; Zhou, Weibiao; Curran, Philip; Yu, Bin

    2012-09-15

    Calamansi juices from three countries (Malaysia, the Philippines and Vietnam) were characterised through measuring volatiles, physicochemical properties and non-volatiles (sugars, organic acids and phenolic acids). The volatile components of manually squeezed calamansi juices were extracted using dichloromethane and headspace solid-phase microextraction, and then analysed using gas chromatography-mass spectrometry/flame ionisation detector, respectively. A total of 60 volatile compounds were identified. The results indicated that the Vietnam calamansi juice contained the highest amount of volatiles. Two principal components obtained from principal component analysis (PCA) represented 89.65% of the cumulative total variations of the volatiles. Among the non-volatile components, these three calamansi juices could be, to some extent, differentiated according to fructose and glucose concentrations. Hence, this study of calamansi juices could lead to a better understanding of calamansi fruits.

  5. On guidance and volatility

    NARCIS (Netherlands)

    Billings, M.B.; Jennings, R.; Lev, B.

    2013-01-01

    Survey evidence suggests that managers voluntarily disclose information, particularly earnings guidance, with an aim toward dampening share price volatility. Yet, consultants and influential institutions advise against providing guidance — citing fears of litigation and market penalties associated w

  6. Dynamic Volatility Arbitrage

    DEFF Research Database (Denmark)

    Dorn, Jochen

    profit on well-developed markets. Dynamic participation features on cross asset portfolios are at rst sight a remedy to that dilemma. Based on volatility thresholds and portfolio re-balancing, the fund engineers try to create a "volatility guaranteed" investment opportunity by surfing on the unusual high...... concepts, next to nothing is known about position reverting strategies and how, and -even more important- in which context they are applied in practice. In the recent market downturn only one sector generated signicant profits for the leading investment banks: Volatility trading activities, namely on Forex......, interest rates and commodities. If an investor positions himself on the (volatility) market within a long/short trading framework, he typically bets on a traditional mispricing arbitrage. However as this corresponds to a call spread with equal exercise prices, this strategy alone would not generate enough...

  7. It’s all about volatility of volatility

    DEFF Research Database (Denmark)

    Grassi, Stefano; Santucci de Magistris, Paolo

    2015-01-01

    for the realized volatility series. It emerges that during the recent financial crisis the relative weight of the daily component dominates over the monthly term. The estimates of the two factor stochastic volatility model suggest that the change in the dynamic structure of the realized volatility during...... the financial crisis is due to the increase in the volatility of the persistent volatility term. A set of Monte Carlo simulations highlights the robustness of the methodology adopted in tracking the dynamics of the parameters....

  8. GC-MS Combined with Retention Index Analysis for Volatile Ingredients in Curcumae Rhizoma by Static Headspace%静态顶空进样GC-MS结合保留指数分析莪术挥发性成分

    Institute of Scientific and Technical Information of China (English)

    巩丽丽

    2011-01-01

    Objective To analyze the volatile ingredients in Curcumae Rhizoma. Methods With the application of static headspace, volatile ingredients in Curcumae Rhizoma were analyzed and identified by GC-MS combined with retention index. Results 61 components in Curcumae Rhizoma were detected by GC-MS and 41 main volatile ingredients were identified combined with retention index. Conclusions Static headspace is a simple, efficient method to collect volatile compounds in Curcumae Rhizoma. The results obtained by GC-MS combined with retention index were proved to be more accurate.%目的 分析莪术中的挥发性成分.方法 采用静态顶空进样技术采集莪术的挥发性成分,GC-MS结合保留指数对其联合定性.结果 采用GC-MS分析,检出61个组分;结合保留指数定性,鉴定出41个主要挥发性成分.结论 静态顶空进样分析莪术挥发性成分,操作更简单、快速并节省药材;GC-MS结合保留指数联合定性使分析结果更准确.

  9. Non-volatile memories

    CERN Document Server

    Lacaze, Pierre-Camille

    2014-01-01

    Written for scientists, researchers, and engineers, Non-volatile Memories describes the recent research and implementations in relation to the design of a new generation of non-volatile electronic memories. The objective is to replace existing memories (DRAM, SRAM, EEPROM, Flash, etc.) with a universal memory model likely to reach better performances than the current types of memory: extremely high commutation speeds, high implantation densities and retention time of information of about ten years.

  10. Visualization of electrolyte volatile phenomenon in DIR-MCFC

    Science.gov (United States)

    Sugiura, Kimihiko; Yodo, Tadakatsu; Yamauchi, Makoto; Tanimoto, Kazumi

    Volatilization of molten salt is one of the factors that control the performance of molten carbonate fuel cells (MCFC). Volatilization of molten salt promotes cross-leakage and the corrosion of metallic components. Moreover, piping blockage is caused by the solidification of volatile matter. Because reforming catalysts filling the anode channel are polluted by molten salt volatile matter in direct internal reforming molten carbonate fuel cells (DIR-MCFC), the volatilization of molten salt is an especially serious subject. However, neither the behaviour nor the volatilization volume of molten salt volatile matter has heretofore been elucidated on. Because molten salt volatile matter that has strong alkalinity cannot be supplied directly to an analyzer, its volatilization volume is small, and analytical accuracy is poor. Therefore, an attempt has been made to elucidate about the electrolyte volatile phenomenon in an MCFC by using a non-contact image measurement technique. A 16 cm 2 MCFC single cell frame has an observation window and an irradiation window. The image of the volatile phenomenon is shown by irradiating a YAG laser light sheet 2 mm thick from an irradiation window into the anode channel, and taking measurements from an observation window with a high spatial resolution video camera (12 bit). As a result, though the volatile matter is not observed in an anode channel at OCV, the volatile matter flows in a belt-like manner from the inlet side near the electrode toward the outlet at a current density of 150 mA cm -2. In addition, volatile matter is difficult to observe with the conventional thickness of an anode electrode. Because the composition of these volatile matters is 15Li 2CO 3/85K 2CO 3 (the result of conversion into molten salt) by ion chromatography analysis, it is not an electrolyte (62Li 2CO 3/38K 2CO 3) but rather the volatile matter of potassium, such as KOH. Therefore, it is understood that the volatile matter K 2CO 3 is generated as KOH

  11. Using in situ GC-MS for analysis of C2-C7 volatile organic acids in ambient air of a boreal forest site

    Science.gov (United States)

    Hellén, Heidi; Schallhart, Simon; Praplan, Arnaud P.; Petäjä, Tuukka; Hakola, Hannele

    2017-01-01

    An in situ method for studying gas-phase C2-C7 monocarboxylic volatile organic acids (VOAs) in ambient air was developed and evaluated. Samples were collected directly into the cold trap of the thermal desorption unit (TD) and analysed in situ using a gas chromatograph (GC) coupled to a mass spectrometer (MS). A polyethylene glycol column was used for separating the acids. The method was validated in the laboratory and tested on the ambient air of a boreal forest in June 2015. Recoveries of VOAs from fluorinated ethylene propylene (FEP) and heated stainless steel inlets ranged from 83 to 123 %. Different VOAs were fully desorbed from the cold trap and well separated in the chromatograms. Detection limits varied between 1 and 130 pptv and total uncertainty of the method at mean ambient mixing ratios was between 16 and 76 %. All straight chain VOAs except heptanoic acid in the ambient air measurements were found with mixing ratios above the detection limits. The highest mixing ratios were found for acetic acid and the highest relative variations for hexanoic acid. In addition, mixing ratios of acetic and propanoic acids measured by the novel GC-MS method were compared with proton-mass-transfer time-of-flight mass spectrometer (PTR-TOFMS) data. Both instruments showed similar variations, but differences in the mixing ratio levels were significant.

  12. Spatial-data sharing: Applying social-network analysis to study individual and collective behaviour

    NARCIS (Netherlands)

    Omran, E.S.E.; Etten, van J.

    2007-01-01

    Spatial-Data Sharing (SDS) is a crucial aspect of spatial-data infrastructures. This paper introduces Social-Network Analysis to research on SDS. By mapping out relationships among social actors using Social-Network Analysis, the collective properties of SDS in organizations can be investigated. Pre

  13. Ultimate detectability of volatile organic compounds: how much further can we reduce their ambient air sample volumes for analysis?

    Science.gov (United States)

    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.

  14. HISTORICAL AND IMPLIED VOLATILITY: AN INVESTIGATION INTO NSE NIFTY FUTURES AND OPTIONS

    Directory of Open Access Journals (Sweden)

    N R Parasuraman

    2011-10-01

    Full Text Available The broad objective of the paper is to have an understanding of the movement of volatility over a fair period in respect of the market portfolio. Also, it enables an understanding on how divergent the implied volatility has been from this estimate. It uses Volatility Cone, Volatility Smile and Volatility Surface as the parameters. The study takes different rolling periods percentiles of volatility. Hoadley Options Calculator is used for calculation and analysis purpose. The study empirically proves that there is a clear reversion to the mean as indicated by the volatility cone. The study of volatility smiles in respect of NIFTY options throws up different patterns. The Garch (1.1 model reveals that historical volatility for the period from 2004 to 2004 and for the year 2009 were estimated. Interestingly, but not totally surprisingly, the average implied volatility of calls and puts on Nifty during the period January to March 2010 showed differences.

  15. Analysis of volatiles in meat from Iberian pigs and lean pigs after refrigeration and cooking by using SPME-GC-MS.

    Science.gov (United States)

    Estévez, Mario; Morcuende, David; Ventanas, Sonia; Cava, Ramón

    2003-05-21

    The volatile compounds generated in meat from Iberian and lean pigs after four different treatments (raw, refrigerated, cooked, and refrigerated cooked meat) were analyzed. The different treatments showed different volatile profiles. Methyl alcohols and ketones (such as 2-ethyl-hexan-1-ol, 2-methyl-butan-1-ol, 3-methyl-butan-1-ol, and 3-hydroxy-butan-2-one) were the most representative in refrigerated meat because of the degradation of carbohydrates and proteins together with the Strecker degradation pathway. Lipid-derived volatiles were the most abundant in cooked meat and refrigerated cooked meat. Meat from different pig breeds presented different volatile profiles, probably due to different enzymatic and oxidative deterioration susceptibility. Otherwise, the fat content and its compositional characteristics also played an important role in the generation of volatiles. As compared to samples from lean pigs, muscles from Iberian pigs showed a higher content of heme iron that may have promoted the generation of higher content of total lipid-derived volatiles during the refrigeration of cooked meat. Despite that, the formation of volatiles with low thresholds and related to intense rancidity perception likely to be derived from polyunsaturated fatty acids was higher in lean pork than in meat from Iberian pigs. This might be expected to lead to a more intense development of a warmed over flavor during refrigeration of cooked samples from lean pigs.

  16. Variation of volatile compounds among wheat varieties and landraces.

    Science.gov (United States)

    Starr, G; Petersen, M A; Jespersen, B M; Hansen, Å S

    2015-05-01

    Analysis of volatile compounds was performed on 81 wheat varieties and landraces, grown under controlled greenhouse conditions, in order to investigate the possibility of differentiating wheat varieties according to their volatile compound profiles. Volatile compounds from wheat samples were extracted by dynamic headspace extraction and analysed by gas chromatography-mass spectrometry. Seventy-two volatile compounds were identified in the wheat samples. Multivariate analysis of the data showed a large diversity in volatile profiles between samples. Differences occurred between samples from Austria compared to British, French and Danish varieties. Landraces were distinguishable from modern varieties and they were characterised by higher averaged peak areas for esters, alcohols, and some furans. Modern varieties were characterised by higher averaged peak areas for terpenes, pyrazines and straight-chained aldehydes. Differences in volatile profiles are demonstrated between wheat samples for the first time, based on variety. These results are significant to plant breeders and commercial users of wheat.

  17. Volatilization mechanism of certain elements in a method of semiquantitative spectrographic analysis; Mecanismo de volatilizacion de ciertos elementos en un metodo de analisis espectrografico semicuantitativo

    Energy Technology Data Exchange (ETDEWEB)

    Diaz-Guerra, J. P.

    1972-07-01

    The efficiency of the compounds GeO{sub 2}, Li{sub 2}B{sub 4}O{sub 7}, Li{sub 2}CO{sub 3}, SiO{sub 2} and SrCO{sub 3} as spectrochemical buffers, in the development of a semiquantitative spectrographic method of analysis, that can be applied to the determination of 47 elements in different matrices, has been tested. It has been shown that trough the use of Li{sub 2}B{sub 4}O{sub 7} or Geo{sub 2} adequate accuracy is obtained, attaining with the latter the detection of much lower concentrations, specially for the elements Mo. Ti, V and W. In order to account for the different behaviour of these elements their volatilization mechanism has been studied. MoB{sub 2}, TiB{sub 2}, VB{sub 2}.{delta}WB and {epsilon}-WB were found, by x-ray diffraction analysis, to be reaction products in the case of mixtures with Li{sub 2}B{sub 4}O{sub 7}. (Author)

  18. High-Throughput and Low-Cost Analysis of Trace Volatile Phthalates in Seafood by Online Coupling of Monolithic Capillary Adsorbent with GC-MS.

    Science.gov (United States)

    Insuan, Wimonrut; Khawmodjod, Phatchara; Whitlow, Harry J; Soonthondecha, Peerapong; Malem, Fairda; Chienthavorn, Orapin

    2016-04-27

    A simple, sensitive, and high-throughput method was developed for the determination of six volatile phthalate esters-dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), benzylbutyl phthalate (BBP), di(2-ethylhexyl) phthalate (DEHP), and di-n-octyl phthalate (DnOP)-in seafood samples by using monolith adsorbent in a capillary coupled to a gas chromatography-mass spectrometry (GC-MS) system. The freeze-dried samples were subjected to an ultrasonication with hexane, followed by vortex mixing. The liquid extract was quantitatively determined by a direct application to an online silica monolith capillary adsorbent coupled with a gas chromatograph with mass spectrometric detection. Method validation in seafood matrix gave recoveries of 72.8-85.4% and a detection limit of 6.8-10.0 ng g(-1) for bivalve samples. Reusability of the monolith capillary for trapping coextracted matrix was up to six times, allowing high-throughput analysis at the parts per billion level. When compared with the Food and Environment Research Agency (FERA) method, no significant difference in the result was observed, confirming the method was valid and applicable for the routine analysis of phthalates in seafood samples for food and environmental laboratories.

  19. Oil and stock market volatility: A multivariate stochastic volatility perspective

    Energy Technology Data Exchange (ETDEWEB)

    Vo, Minh, E-mail: minh.vo@metrostate.edu

    2011-09-15

    This paper models the volatility of stock and oil futures markets using the multivariate stochastic volatility structure in an attempt to extract information intertwined in both markets for risk prediction. It offers four major findings. First, the stock and oil futures prices are inter-related. Their correlation follows a time-varying dynamic process and tends to increase when the markets are more volatile. Second, conditioned on the past information, the volatility in each market is very persistent, i.e., it varies in a predictable manner. Third, there is inter-market dependence in volatility. Innovations that hit either market can affect the volatility in the other market. In other words, conditioned on the persistence and the past volatility in their respective markets, the past volatility of the stock (oil futures) market also has predictive power over the future volatility of the oil futures (stock) market. Finally, the model produces more accurate Value-at-Risk estimates than other benchmarks commonly used in the financial industry. - Research Highlights: > This paper models the volatility of stock and oil futures markets using the multivariate stochastic volatility model. > The correlation between the two markets follows a time-varying dynamic process which tends to increase when the markets are more volatile. > The volatility in each market is very persistent. > Innovations that hit either market can affect the volatility in the other market. > The model produces more accurate Value-at-Risk estimates than other benchmarks commonly used in the financial industry.

  20. GCM Analysis of the collective properties of lead isotopes with exact projection on particle numbers

    CERN Document Server

    Heenen, P H; Bender, M; Bonche, P; Flocard, Hubert

    2001-01-01

    We present a microscopic analysis of the collective behaviour of the lead isotopes in the vicinity of Pb208. In this study, we rely on a coherent approach based on the Generator Coordinate Method including exact projection on N and Z numbers within a collective space generated by means of the constrained Hartree-Fock BCS method. With the same Hamiltonian used in HF+BCS calculations, we have performed a comprehensive study including monopole, quadrupole and octupole excitations as well as pairing vibrations. We find that, for the considered nuclei, the collective modes which modify the most the conclusions drawn from the mean-field theory are the octupole and pairing vibrations.

  1. Evaluation of volatile organic compound (VOC) blank data and application of study reporting levels to groundwater data collected for the California GAMA Priority Basin Project, May 2004 through September 2010

    Science.gov (United States)

    Fram, Miranda S.; Olsen, Lisa D.; Belitz, Kenneth

    2012-01-01

    Volatile organic compounds (VOCs) were analyzed in quality-control samples collected for the California Groundwater Ambient Monitoring and Assessment (GAMA) Program Priority Basin Project. From May 2004 through September 2010, a total of 2,026 groundwater samples, 211 field blanks, and 109 source-solution blanks were collected and analyzed for concentrations of 85 VOCs. Results from analyses of these field and source-solution blanks and of 2,411 laboratory instrument blanks during the same time period were used to assess the quality of data for the 2,026 groundwater samples. Eighteen VOCs were detected in field blanks or source-solution blanks: acetone, benzene, bromodichloromethane, 2-butanone, carbon disulfide, chloroform, 1,1-dichloroethene, dichloromethane, ethylbenzene, tetrachloroethene, styrene, tetrahydrofuran, toluene, trichloroethene, trichlorofluoromethane, 1,2,4-trimethylbenzene, m- and p-xylenes, and o-xylene. The objective of the evaluation of the VOC-blank data was to determine if study reporting levels (SRLs) were needed for any of the VOCs detected in blanks to ensure the quality of the data from groundwater samples. An SRL is equivalent to a raised reporting level that is used in place of the reporting level used by the analyzing laboratory [long‑term method detection level (LT-MDL) or laboratory reporting level (LRL)] to reduce the probability of reporting false-positive detections. Evaluation of VOC-blank data was done in three stages: (1) identification of a set of representative quality‑control field blanks (QCFBs) to be used for calculation of SRLs and identification of VOCs amenable to the SRL approach, (2) evaluation of potential sources of contamination to blanks and groundwater samples by VOCs detected in field blanks, and (3) selection of appropriate SRLs from among four potential SRLs for VOCs detected in field blanks and application of those SRLs to the groundwater data. An important conclusion from this study is that to ensure the

  2. Comparison of thermal behavior of natural and hot-washed sisal fibers based on their main components: Cellulose, xylan and lignin. TG-FTIR analysis of volatile products

    Energy Technology Data Exchange (ETDEWEB)

    Benítez-Guerrero, Mónica, E-mail: monica_benitez_guerrero@yahoo.es [Departamento de Ingeniería Civil, Materiales y Fabricación, Universidad de Málaga, Escuela de Ingenierías, C/ Dr. Ortiz Ramos s/n, Campus Teatinos, 29071 Málaga (Spain); López-Beceiro, Jorge [Departamento de Ingeniería Industrial II, Escola Politécnica Superior, Universidade da Coruña, Avda. Mendizábal, 15403 Ferrol (Spain); Sánchez-Jiménez, Pedro E. [Instituto de Ciencia de Materiales de Sevilla, CSIC-Universidad de Sevilla, C/ Américo Vespucio 49, 41092 Sevilla (Spain); Pascual-Cosp, José [Departamento de Ingeniería Civil, Materiales y Fabricación, Universidad de Málaga, Escuela de Ingenierías, C/ Dr. Ortiz Ramos s/n, Campus Teatinos, 29071 Málaga (Spain)

    2014-04-01

    Highlights: • Thermal decomposition of sisal fibers has been discussed. • Decompositions of lignocellulosic components and sisal are compared by TXRD and TG-FTIR. • Hot washing reduces the temperature range in which sisal decomposition occurs. • Sisal cellulose decomposition goes by an alternative route to levoglucosan generation. - Abstract: This paper presents in a comprehensive way the thermal behavior of natural and hot-washed sisal fibers, based on the fundamental components of lignocellulosic materials: cellulose, xylan and lignin. The research highlights the influence exerted on the thermal stability of sisal fibers by other constituents such as non-cellulosic polysaccharides (NCP) and mineral matter. Thermal changes were investigated by thermal X-ray diffraction (TXRD), analyzing the crystallinity index (%Ic) of cellulosic samples, and by simultaneous thermogravimetric and differential thermal analysis coupled with Fourier-transformed infrared spectrometry (TG/DTA-FTIR), which allowed to examine the evolution of the main volatile compounds evolved during the degradation under inert and oxidizing atmospheres. The work demonstrates the potential of this technique to elucidate different steps during the thermal decomposition of sisal, providing extensible results to other lignocellulosic fibers, through the analysis of the evolution of CO{sub 2}, CO, H{sub 2}O, CH{sub 4}, acetic acid, formic acid, methanol, formaldehyde and 2-butanone, and comparing it with the volatile products from pyrolysis of the biomass components. The hydroxyacetaldehyde detected during pyrolysis of sisal is indicative of an alternative route to that of levoglucosan, generated during cellulose pyrolysis. Hot-washing at 75 °C mostly extracts non-cellulosic components of low decomposition temperature, and reduces the range of temperature in which sisal decomposition occurs, causing a retard in the pyrolysis stage and increasing Tb{sub NCP} and Tb{sub CEL}, temperatures at the

  3. Volatile flavor compounds in yogurt: a review.

    Science.gov (United States)

    Cheng, Hefa

    2010-11-01

    Considerable knowledge has been accumulated on the volatile compounds contributing to the aroma and flavor of yogurt. This review outlines the production of the major flavor compounds in yogurt fermentation and the analysis techniques, both instrumental and sensory, for quantifying the volatile compounds in yogurt. The volatile compounds that have been identified in plain yogurt are summarized, with the few key aroma compounds described in detail. Most flavor compounds in yogurt are produced from lipolysis of milkfat and microbiological transformations of lactose and citrate. More than 100 volatiles, including carbonyl compounds, alcohols, acids, esters, hydrocarbons, aromatic compounds, sulfur-containing compounds, and heterocyclic compounds, are found in yogurt at low to trace concentrations. Besides lactic acid, acetaldehyde, diacetyl, acetoin, acetone, and 2-butanone contribute most to the typical aroma and flavor of yogurt. Extended storage of yogurt causes off-flavor development, which is mainly attributed to the production of undesired aldehydes and fatty acids during lipid oxidation. Further work on studying the volatile flavor compounds-matrix interactions, flavor release mechanisms, and the synergistic effect of flavor compounds, and on correlating the sensory properties of yogurt with the compositions of volatile flavor compounds are needed to fully elucidate yogurt aroma and flavor.

  4. Market volatility modeling for short time window

    Science.gov (United States)

    de Mattos Neto, Paulo S. G.; Silva, David A.; Ferreira, Tiago A. E.; Cavalcanti, George D. C.

    2011-10-01

    The gain or loss of an investment can be defined by the movement of the market. This movement can be estimated by the difference between the magnitudes of two stock prices in distinct periods and this difference can be used to calculate the volatility of the markets. The volatility characterizes the sensitivity of a market change in the world economy. Traditionally, the probability density function (pdf) of the movement of the markets is analyzed by using power laws. The contributions of this work is two-fold: (i) an analysis of the volatility dynamic of the world market indexes is performed by using a two-year window time data. In this case, the experiments show that the pdf of the volatility is better fitted by exponential function than power laws, in all range of pdf; (ii) after that, we investigate a relationship between the volatility of the markets and the coefficient of the exponential function based on the Maxwell-Boltzmann ideal gas theory. The results show an inverse relationship between the volatility and the coefficient of the exponential function. This information can be used, for example, to predict the future behavior of the markets or to cluster the markets in order to analyze economic patterns.

  5. Wind energy Computerized Maintenance Management System (CMMS) : data collection recommendations for reliability analysis.

    Energy Technology Data Exchange (ETDEWEB)

    Peters, Valerie A.; Ogilvie, Alistair; Veers, Paul S.

    2009-09-01

    This report addresses the general data requirements for reliability analysis of fielded wind turbines and other wind plant equipment. The report provides a list of the data needed to support reliability and availability analysis, and gives specific recommendations for a Computerized Maintenance Management System (CMMS) to support automated analysis. This data collection recommendations report was written by Sandia National Laboratories to address the general data requirements for reliability analysis of fielded wind turbines. This report is intended to help the reader develop a basic understanding of what data are needed from a Computerized Maintenance Management System (CMMS) and other data systems, for reliability analysis. The report provides: (1) a list of the data needed to support reliability and availability analysis; and (2) specific recommendations for a CMMS to support automated analysis. Though written for reliability analysis of wind turbines, much of the information is applicable to a wider variety of equipment and a wider variety of analysis and reporting needs.

  6. Full cost accounting in the analysis of separated waste collection efficiency: A methodological proposal.

    Science.gov (United States)

    D'Onza, Giuseppe; Greco, Giulio; Allegrini, Marco

    2016-02-01

    Recycling implies additional costs for separated municipal solid waste (MSW) collection. The aim of the present study is to propose and implement a management tool - the full cost accounting (FCA) method - to calculate the full collection costs of different types of waste. Our analysis aims for a better understanding of the difficulties of putting FCA into practice in the MSW sector. We propose a FCA methodology that uses standard cost and actual quantities to calculate the collection costs of separate and undifferentiated waste. Our methodology allows cost efficiency analysis and benchmarking, overcoming problems related to firm-specific accounting choices, earnings management policies and purchase policies. Our methodology allows benchmarking and variance analysis that can be used to identify the causes of off-standards performance and guide managers to deploy resources more efficiently. Our methodology can be implemented by companies lacking a sophisticated management accounting system.

  7. Variação anual do rendimento e composição química dos componentes voláteis da Siparuna guianensis Aublet Annual variation of yield and chemical composition of volatile components of Siparuna guianensis Aublet

    Directory of Open Access Journals (Sweden)

    Carla Maria Abido Valentini

    2010-01-01

    Full Text Available This work describes the volatile composition obtained by hidrodistillation of fresh leaves of Siparuna guianensis Aublet collected from Cuiabá (MT, Brazil. The composition of DCM extract of hydrolate was determined by GC-MS analysis and the results showed that the specie present a range of components according to their phenology and period of the leaves were collects. The highest volatile components yield was obtained during the reproductive period and the principal compound was the siparunone.

  8. Measurement of breakthrough volumes of volatile chemical warfare agents on a poly(2,6-diphenylphenylene oxide)-based adsorbent and application to thermal desorption-gas chromatography/mass spectrometric analysis.

    Science.gov (United States)

    Kanamori-Kataoka, Mieko; Seto, Yasuo

    2015-09-04

    recovered, whereas VX and Russian VX were recovered in the same concentration range. The results indicate that CWA vapors, with the exception of VX and Russian VX, can be measured by an on-site collection procedure using the Tenax(®) TA resin tubes, followed by a subsequent TD-GC/MS analysis.

  9. Gas chromatography mass spectrometry computer analysis of volatile halogenated hydrocarbons in man and his environment--A multimedia environmental study.

    Science.gov (United States)

    Barkley, J; Bunch, J; Bursey, J T; Castillo, N; Cooper, S D; Davis, J M; Erickson, M D; Harris, B S; Kirkpatrick, M; Michael, L C; Parks, S P; Pellizzari, E D; Ray, M; Smith, D; Tomer, K B; Wagner, R; Zweidinger, R A

    1980-04-01

    As part of a study to make a comparative analysis of selected halogenated compounds in man and the environmental media, a quantitative gas chromatography mass spectrometric analysis of the levels of the halogenated compounds found in the breath, blood and urine of an exposed population (Old Love Canal area, Niagara, New York) and their immediate environment (air and water) was undertaken. In addition, levels of halogenated hydrocarbons in air samples taken in the general Buffalo, Niagara Falls area were determined.

  10. Dynamic Factor Models for the Volatility Surface

    DEFF Research Database (Denmark)

    van der Wel, Michel; Ozturk, Sait R.; Dijk, Dick van

    The implied volatility surface is the collection of volatilities implied by option contracts for different strike prices and time-to-maturity. We study factor models to capture the dynamics of this three-dimensional implied volatility surface. Three model types are considered to examine desirable...... features for representing the surface and its dynamics: a general dynamic factor model, restricted factor models designed to capture the key features of the surface along the moneyness and maturity dimensions, and in-between spline-based methods. Key findings are that: (i) the restricted and spline......-based models are both rejected against the general dynamic factor model, (ii) the factors driving the surface are highly persistent, (iii) for the restricted models option Delta is preferred over the more often used strike relative to spot price as measure for moneyness....

  11. Complexity and Multifractal of Volatility Duration for Agent-Based Financial Dynamics and Real Markets

    Science.gov (United States)

    Yang, Ge; Wang, Jun

    2016-11-01

    A random agent-based financial model is developed and investigated by the finite-range multitype contact dynamic system, in an attempt to reproduce and study the dynamics of financial markets. And an analysis method of detecting duration and intensity relationship in volatility series is introduced, called the volatility duration analysis. Then the auto-correlation analysis suggests that there exists evident volatility clustering feature in absolute volatility durations for the simulation data and the real data. Besides, the Lempel-Ziv complexity analysis is applied to study the complexity of the returns, the corresponding absolute returns and the volatility duration returns, which can reflect the fluctuation behaviors, the volatility behaviors and the volatility duration behaviors. At last, the multifractal phenomena of volatility durations of returns are comparatively studied for Shanghai Composite Index and the proposed model by multifractal detrended fluctuation analysis.

  12. Incorporating the value of changes in price volatility into cost-benefit analysis-an application to oil prices in the transport sector

    DEFF Research Database (Denmark)

    Jensen, Thomas Christian; Møller, Flemming

    2010-01-01

    in the policy assessment taking into account the most significant correlations between prices of alternative fuels and between fuel prices and consumption in general. In the present paper, a method of valuing changes in price volatility based on portfolio theory is applied to some very simple transport......This paper contains a tentative suggestion of how to take into account the value of changes in price volatility in real world cost-benefit analyses. Price volatility is an important aspect of security of supply which first of all concerns physical availability, but assuming that consumers are risk...... averse, security of supply can also be viewed as a matter of avoiding oscillations in consumption originating from volatile prices of for instance oil. When the government makes transport-related choices on behalf of the consumers, the effect on oscillations in general consumption should be included...

  13. Development and validation of automatic HS-SPME with a gas chromatography-ion trap/mass spectrometry method for analysis of volatiles in wines.

    Science.gov (United States)

    Paula Barros, Elisabete; Moreira, Nathalie; Elias Pereira, Giuliano; Leite, Selma Gomes Ferreira; Moraes Rezende, Claudia; Guedes de Pinho, Paula

    2012-11-15

    An automated headspace solid-phase microextraction (HS-SPME) combined with gas chromatography-ion trap/mass spectrometry (GC-IT/MS) was developed in order to quantify a large number of volatile compounds in wines such as alcohols, ester, norisoprenoids and terpenes. The procedures were optimized for SPME fiber selection, pre-incubation temperature and time, extraction temperature and time, and salt addition. A central composite experimental design was used in the optimization of the extraction conditions. The volatile compounds showed optimal extraction using a DVB/CAR/PDMS fiber, incubation of 5 ml of wine with 2g NaCl at 45 °C during 5 min, and subsequent extraction of 30 min at the same temperature. The method allowed the identification of 64 volatile compounds. Afterwards, the method was validated successfully for the most significant compounds and was applied to study the volatile composition of different white wines.

  14. Changes in dark chocolate volatiles during storage.

    Science.gov (United States)

    Nightingale, Lia M; Cadwallader, Keith R; Engeseth, Nicki J

    2012-05-09

    Chocolate storage is critical to the quality of the final product. Inadequate storage, especially with temperature fluctuations, may lead to a change in crystal structure, which may eventually cause fat bloom. Bloom is the main cause of quality loss in the chocolate industry. The impact of various storage conditions on the flavor quality of dark chocolate was determined. Dark chocolate was stored in different conditions leading to either fat or sugar bloom and analyzed at 0, 4, and 8 weeks of storage. Changes in chocolate flavor were determined by volatile analysis and descriptive sensory evaluation. Results were analyzed by analysis of variance (ANOVA), cluster analysis, principal component analysis (PCA), and linear partial least-squares regression analysis (PLS). Volatile concentration and loss were significantly affected by storage conditions. Chocolates stored at high temperature were the most visually and texturally compromised, but volatile concentrations were affected the least, whereas samples stored at ambient, frozen, and high relative humidity conditions had significant volatile loss during storage. It was determined that high-temperature storage caused a change in crystal state due to the polymorphic shift to form VI, leading to an increase in sample hardness. Decreased solid fat content (SFC) during high-temperature storage increased instrumentally determined volatile retention, although no difference was detected in chocolate flavor during sensory analysis, possibly due to instrumental and sensory sampling techniques. When all instrumental and sensory data had been taken into account, the storage condition that had the least impact on texture, surface roughness, grain size, lipid polymorphism, fat bloom formation, volatile concentrations, and sensory attributes was storage at constant temperature and 75% relative humidity.

  15. Protocol for Data Collection and Analysis Applied to Automated Facial Expression Analysis Technology and Temporal Analysis for Sensory Evaluation.

    Science.gov (United States)

    Crist, Courtney A; Duncan, Susan E; Gallagher, Daniel L

    2016-08-26

    We demonstrate a method for capturing emotional response to beverages and liquefied foods in a sensory evaluation laboratory using automated facial expression analysis (AFEA) software. Additionally, we demonstrate a method for extracting relevant emotional data output and plotting the emotional response of a population over a specified time frame. By time pairing each participant's treatment response to a control stimulus (baseline), the overall emotional response over time and across multiple participants can be quantified. AFEA is a prospective analytical tool for assessing unbiased response to food and beverages. At present, most research has mainly focused on beverages. Methodologies and analyses have not yet been standardized for the application of AFEA to beverages and foods; however, a consistent standard methodology is needed. Optimizing video capture procedures and resulting video quality aids in a successful collection of emotional response to foods. Furthermore, the methodology of data analysis is novel for extracting the pertinent data relevant to the emotional response. The combinations of video capture optimization and data analysis will aid in standardizing the protocol for automated facial expression analysis and interpretation of emotional response data.

  16. GC-MS Analysis of Coriander Volatile Oils from Yuxi County in Yunnan Province%云南玉溪芜荽挥发油成分的GG-MS分析

    Institute of Scientific and Technical Information of China (English)

    张京娜; 陈霞; 杨冬; 张颖君; 杨崇仁

    2009-01-01

    目的 分析云南玉溪产芜荽的挥发油成分,比较不同产地芜荽挥发油组成,讨论其差异.方法 采用水蒸气蒸馏法从云南玉溪产芜荽中提取挥发油,通过气相色谱-质谱联用系统对挥发性成分进行分析.结果 检出41个色谱峰,用峰面积归一化法得出色谱峰的相时含量;与数据库时照,鉴定了其中的35个化合物.结论 云南玉溪产芜荽的挥发油成分与文献报道其它产地的有显著差异.%Objective To discuss the chemical differences of Coriander volatile oils from different producing areas. Methods Coriander volatile oils from Yuxi county of Yunnan was obtained by steam distillation extraction method. Results There are 41 peaks from the volatile oils were showed by GC-MS analysis. The relative content of each peak was detected by the normalization method of peak area. Among them, 35 peaks were identified by compared with MS database. Conclusion The volatile oils components of Yuxi Coriander had significant differences with that of other producing areas.

  17. Analysis of volatile constituents in beeswax using HS-GC/MS%顶空-气质联用测定黑龙江地产蜂蜡中挥发性成分

    Institute of Scientific and Technical Information of China (English)

    李光; 张宁; 雷勇; 孙慧峰

    2011-01-01

    目的:研究蜂蜡挥发性成分.方法:采用顶空-气质联用手段进行测定,利用ChemStation、AMDIS、NIST05库相结合的方法对分离得到的化合物进行结构鉴定,应用相对峰面积法计算相对百分含量.结果:分离得到色谱峰34种,确定了其中29种化合物,其中大部分成分在蜂蜡中首次报道.结论:应用顶空气一质联用技术能够全面、便捷测定蜂蜡中挥发性成分.%Objective: To study the volatile constituents from beeswax sample. Methods: The volatile constituents of beeswax which were analyzed by Head Space-Gas Chromatography-Mass Spectra. The constituents were identified by their mass spectra using ChemStation, AMDIS and NIST05. The relative percentage of volatile constituents was calculated from the GC peak areas. Results: Thirty-four kinds of chemical constituents in beeswax were separated, of which twenty-nine compounds were characterized. Conclusion: HS-GC/MS was simple and less sample-demanding and can be used for the fast analysis of the volatile constituents of beeswax.

  18. Understanding Interest Rate Volatility

    DEFF Research Database (Denmark)

    Volker, Desi

    This thesis is the result of my Ph.D. studies at the Department of Finance of the Copenhagen Business School. It consists of three essays covering topics related to the term structure of interest rates, monetary policy and interest rate volatility. The rst essay, \\Monetary Policy Uncertainty...... and Interest Rates", examines the role of monetary policy uncertainty on the term structure of interest rates. The second essay, \\A Regime-Switching A ne Term Structure Model with Stochastic Volatility" (co-authored with Sebastian Fux), investigates the ability of the class of regime switching models...... with and without stochastic volatility to capture the main stylized features of U.S. interest rates. The third essay, \\Variance Risk Premia in the Interest Rate Swap Market", investigates the time-series and cross-sectional properties of the compensation demanded for holding interest rate variance risk. The essays...

  19. Volatiles in protoplanetary disks

    CERN Document Server

    Pontoppidan, Klaus M; Bergin, Edwin A; Brittain, Sean; Marty, Bernard; Mousis, Olvier; Oberg, Karin L

    2014-01-01

    Volatiles are compounds with low sublimation temperatures, and they make up most of the condensible mass in typical planet-forming environments. They consist of relatively small, often hydrogenated, molecules based on the abundant elements carbon, nitrogen and oxygen. Volatiles are central to the process of planet formation, forming the backbone of a rich chemistry that sets the initial conditions for the formation of planetary atmospheres, and act as a solid mass reservoir catalyzing the formation of planets and planetesimals. This growth has been driven by rapid advances in observations and models of protoplanetary disks, and by a deepening understanding of the cosmochemistry of the solar system. Indeed, it is only in the past few years that representative samples of molecules have been discovered in great abundance throughout protoplanetary disks - enough to begin building a complete budget for the most abundant elements after hydrogen and helium. The spatial distributions of key volatiles are being mapped...

  20. Stochastic volatility selected readings

    CERN Document Server

    Shephard, Neil

    2005-01-01

    Neil Shephard has brought together a set of classic and central papers that have contributed to our understanding of financial volatility. They cover stocks, bonds and currencies and range from 1973 up to 2001. Shephard, a leading researcher in the field, provides a substantial introduction in which he discusses all major issues involved. General Introduction N. Shephard. Part I: Model Building. 1. A Subordinated Stochastic Process Model with Finite Variance for Speculative Prices, (P. K. Clark). 2. Financial Returns Modelled by the Product of Two Stochastic Processes: A Study of Daily Sugar Prices, 1961-7, S. J. Taylor. 3. The Behavior of Random Variables with Nonstationary Variance and the Distribution of Security Prices, B. Rosenberg. 4. The Pricing of Options on Assets with Stochastic Volatilities, J. Hull and A. White. 5. The Dynamics of Exchange Rate Volatility: A Multivariate Latent Factor ARCH Model, F. X. Diebold and M. Nerlove. 6. Multivariate Stochastic Variance Models. 7. Stochastic Autoregressive...