Download or read book Mixture Analysis and Molecular Fluorescence Properties of Polynuclear Aromatic Hydrocarbons PAH by Laser induced Fluorescence Spectroscopy written by Ki-Min Bark and published by . This book was released on 1989 with total page 270 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Large C 24 Polycyclic Aromatic Hydrocarbons written by John C. Fetzer and published by John Wiley & Sons. This book was released on 2000-08-28 with total page 308 pages. Available in PDF, EPUB and Kindle. Book excerpt: Polycyclische aromatische Kohlenwasserstoffe (PAHs) gehören zu den ersten Chemikalien, die als krebserregend für den Menschen erkannt wurden. Erstmals werden in diesem Buch PAHs mit mehr als sieben Ringen auf modernem Stand systematisch abgehandelt. Spezielle Kapitel beschäftigen sich mit Probenvorbereitung und -handling; auch ein Vergleich verschiedener Analyseverfahren ist enthalten. Besonders nützlich für den Laboralltag ist ein ausführlicher Anhang mit Strukturformeln sowie UV-Absorptions- und Fluoreszenz-Emissionsspektren von fast 50 Verbindungen.
Download or read book Laser induced Fluorescence Measurements of Vapor phase Polycyclic Aromatic Hydrocarbons I Evaluation of One and Two photon Excitation Processes for Mixture Analysis II Flame Temperature Measurements Using the Anomalous Fluorescence of Pyrene written by Diane LeAnna Peterson and published by . This book was released on 1988 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Toxicological Profile for Polycyclic Aromatic Hydrocarbons written by and published by . This book was released on 1995 with total page 500 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Applications of Laser Induced Fluorescence Excitation Emission Matrix Spectroscopy for the Analysis of PAHs written by Sean J. Hart and published by . This book was released on 1998 with total page 786 pages. Available in PDF, EPUB and Kindle. Book excerpt: For HPLC and FIA, the data are analyzed by examining the summed fluorescence plots and qualitatively comparing the EEMs with standard measurements made with the same system. Species are qualitatively identified and quantitated by RAFA using pure component EEMs as standards and the EEMs measured during an analysis as the unknowns. RAFA calculated PAH concentrations in HPLC and FIA were in the near-quantitative regime, typically within a factor of 2 of the known concentration for laboratory-prepared mixtures. Several real world samples were analyzed and the results were generally acceptable: for HPLC all components were identified and all except two were quantitated to within a factor of 2. Analysis of lab mixtures by FIA yielded good agreement with known concentrations. The analysis of complex real world samples with many components provided reasonable qualitative identification of species and estimates of concentration.
Download or read book Polycyclic Aromatic Compounds written by Garrigues and published by CRC Press. This book was released on 1993-03-03 with total page 1264 pages. Available in PDF, EPUB and Kindle. Book excerpt: A compilation of some 150 refereed papers that were presented at PAH- 13 (October 1991), the first meeting in the PAH symposium series to be convened outside the US. The papers concern the chemistry, biological effects, and measurement of polycyclic aromatic hydrocarbons and related compounds. Following two papers by Gernot Grimmer, who received the 1991 PAH Award at the meeting for his lifetime contributions in all three of the aforementioned areas, the remaining papers are arranged within 13 sections: standard reference materials and methods; PAH transformation and degradation; molecular modeling and theory; PAH-analysis, methodology; PAH analysis in aquatic systems and geological samples; PAH analysis in emission sources and in ambient air; PAHs in coal and petroleum; metabolic activity, mutagenicity; DNA-adducts, mechanisms, characterization; DNA-binding, metabolic activation; PAH exposure, biomonitoring; Comparative metabolism of B[a]P; and bioactivation, metabolites. (Note: both CIP and Books in Print incorrectly show the title as Polynuclear....) Annotation copyright by Book News, Inc., Portland, OR
Download or read book Use of a Neural Network for the Analysis of Fluorescence Spectra from Mixtures of Polycyclic Aromatic Hydrocarbons written by and published by . This book was released on 1991 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: The use of a software implemented backpropagation neural network is reported for the qualitative and quantitative analysis of the fluorescence emission spectra from multicomponent mixtures of Polycyclic Aromatic Hydrocarbons (PAHs) in solution. Analysis of two types of data is described. First, a backpropagation network is developed to determine the component concentrations in a ternary mixture of PAHs. The input data provided to the network consists of sampled two dimensional (intensity vs. emission wavelength) fluorescence spectra. A second backpropagation network is investigated for the analysis of three dimensional time resolved fluorescence emission spectra for a binary PAH mixture. Both of the networks are trained to recognize preselected compounds. Each trained network is then used to evaluate unknown emission spectra and to determine the presence and relative concentration of the compounds it has learned to recognize. Results from analysis of two dimensional emission spectra show that the trained network was able to successfully identify the individual components and their concentrations in solutions containing mixtures of anthracene, chrysene and acenapthene. Analysis of three-dimensional time resolved fluorescence emission data showed that individual components could be resolved in mixtures of two spectrally similar compounds (anthracene and chrysene). Although a network could also be trained to recognize anthracene and chrysene in binary mixtures using their two-dimensional emission spectra, use of three dimensional time decay spectra reduced the learning time required to train the network by a factor of three. Fluorescence spectroscopy, CIVAPP: fiber optics.
Download or read book Laser Induced Fluorescence Study of the Heterogeneous Interaction of Polycyclic Aromatic Hydrocarbons with Aqueous Surfaces microform Adsorption and Reaction with Gas phase Ozone written by Baagi Thema Mmereki and published by Library and Archives Canada = Bibliothèque et Archives Canada. This book was released on 2005 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt: We have also measured the kinetics and products of a reaction between gas-phase ozone and anthracene adsorbed at the air-aqueous interface. The reactions at the "uncoated" air-water interface and at an interface consisting of a monolayer of various organic compounds were studied. In all the cases, the reaction follows a Langmuir-Hinshelwood mechanism, in which ozone first adsorbs to the air-aqueous interface, and then reacts with adsorbed anthracene. For typical atmospheric ozone concentrations, the estimated reactive uptake coefficient ranges from 2 x 10-8 to 3 x 10-7 depending on the nature of the air-aqueous interface. Smaller (C4, C6) carboxylic acids at the interface inhibit the reaction (compared to the "clean" water surface); 1-octanol enhances it. Under some circumstances, oxidation by ozone on aqueous surfaces may be more important in the atmosphere than gas phase oxidation by OH radicals. The fate of atmospheric semi-volatile organic compounds (SOCs) such as polycyclic aromatic hydrocarbons (PAHs) depends, in part, on their distribution between the gas phase and particulate phases, and oxidation reactions. In the daytime troposphere, photochemically produced OH radicals dominate these reactions, whereas chlorine atoms may contribute to the oxidation of certain PAHs in coastal areas. In the dark, oxidation by nitrate radicals (NO3) may also be important, whereas ozone can contribute to the oxidation both during the day and at night. We have developed a laser-induced fluorescence (LIF) method to study adsorption and oxidation of PAHs at the air-aqueous interface. This method allows to directly probe the mechanisms and extent of PAH uptake on aqueous surfaces. The kinetics of the adsorption of anthracene and pyrene onto "pure" water and water coated with an organic film were measured. The surface uptake coefficients of both PAHs are estimated to be on the order of 10-5, and increase by a factor of 2--3 for uptake to the 1-octanol coated water surface. However, the surface uptake of pyrene to a hexanoic-acid-coated aqueous surface does not display this enhancement. Resolved fluorescence spectra of pyrene adsorbed onto 1-octanol-coated surfaces indicate that pyrene is in a less polar environment than when adsorbed at the hexanoic-acid-coated surfaces.
Download or read book The Development of a High Spectral resolution Laser excited Molecular Fluorescence System and Its Application to Gas Chromatography and the Determination of Polynuclear Aromatic Hydrocarbons written by Scott J. Hein and published by . This book was released on 1988 with total page 690 pages. Available in PDF, EPUB and Kindle. Book excerpt: A high-spectral resolution laser-excited molecular fluorescence system was developed that utilizes a pulsed supersonic expansion to simplify the fluorescence excitation spectra of large, gas-phase aromatic molecules diluted in an excess of a monatomic gas. A microcomputer was used to control and synchronize the instrumental components, which included a Chromatix CMX-4 tunable dye laser, a novel detector/vacuum cell, and a modified automobile fuel injector that was used as the pulsed supersonic nozzle. The spectra of two closely-related, model polynuclear aromatic hydrocarbons (PNAs), fluorene and 1-methylfluorene, were acquired and exhibited spectral bandwidths (FWHM) of 0.1 nm or less, compared to the bandwidths of 5 to 10 nm that are observed in the static gas phase. These high resolution spectra were acquired despite using only a low-volume rotary mechanical pump to maintain the supersonic expansion. The gas-pulse characteristics of the fuel injector were examined to establish proper operation of the valve. In addition, factors such as the type of diluent gas used, and the axial position that the laser intersects the expansion, were examined in terms of their influence on the observed spectra. Helium was determined to be the best diluent gas for this system since the use of argon resulted in the production of significant PNA-Ar clusters. The laser-excited fluorescence system was then interfaced to a packed-column gas chromatograph, which provides both a means of quantitative sample introduction, and the additional selectivity required for the analysis of very complex mixtures. A theoretical model was developed to describe the interaction between the GC mass flow, which is continuous, and the mass flow through the supersonic nozzle, which is pulsed in nature. Fluorescence excitation chromatograms were acquired by monitoring the eluate fluorescence signal at a transition wavelength characteristic of one of the model compounds. A calibration curve was constructed for 1-methylfluorene, and was used to calculate a detection limit of 6 ng. In addition, the excellent selectivity provided by the system was demonstrated by acquiring fluorescence-excitation chromatograms of mixtures containing the two model compounds, using different excitation wavelengths. Finally, the requirements for performing internal standard quantitation with highly selective detectors such as this are discussed. A versatile, programmed-excitation-wavelength scanning method was then developed that allows multiple PNA analytes to be detected in a single chromatographic elution. Relative response factors calculated for fluorene and 1-methylfluorene from replicate chromatograms, were shown to be reproducible, thereby allowing internal standard quantitation to be performed using this detection system.
Download or read book Calculated Molecular Properties of Polycyclic Aromatic Hydrocarbons written by R. A. Hites and published by Elsevier Publishing Company. This book was released on 1987 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt: Polycyclic aromatic hydrocarbons (PAH) are widespread contaminants of the environment arising from both natural and anthropogenic combustion and pyrolysis of organic matter. PAH comprise the largest class of carcinogens known to man. Despite their importance, there is a dearth of information concerning the properties of PAH and many authentic standards are not available. This volume contains a compilation of calculated molecular properties for 272 polycyclic aromatic hydrocarbons (PAH) and monomethylated PAH, listed in sequence according to their increasing molecular weight. The Chemical Abstracts Registry number is also included for easy reference. The molecular properties were calculated using the semiempirical MNDO method with geometric optimization. These parameters include the heats of formation, the frontier orbital energies, the electronic and nuclear energies, the dipole moment, and the net atomic charges on each atom. The shape parameter and the length/breadth ratio from the optimized geometries is also computed.
Download or read book Analytical Laser Induced Fluorescence and Phosphorescence Spectrometry of Aromatic Hydrocarbon Derivatives Prepared in Vapor Deposited Parent Molecule Matrices written by Charles Finley Pace and published by . This book was released on 1986 with total page 516 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Energy Research Abstracts written by and published by . This book was released on 1982 with total page 1696 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Handbook of Polycyclic Aromatic Hydrocarbons written by Guilherme C. Bandeira and published by Nova Science Publishers. This book was released on 2013 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Polycyclic aromatic hydrocarbons (PAHs) are high molecular weight, aromatic compounds containing two or more benzene rings joined together in different ways. They belong to a group of persistent organic pollutants (POPs); are resistant to degradation; and can remain in the environment for long periods with the potential to cause adverse environmental and health effects. This book discusses the chemistry, occurrence and health issues related to PAHs. Topics include PAHs in foods and herbal medicines; biomonitoring of PAHs by pine needles; thermodynamics and phase behavior of polycyclic aromatic hydrocarbons mixtures; occurrence of polycylic aromatic hydrocarbons in cephalopods; children environmentally exposed to PAHs and at risk of genotoxic effects; analysis of PAHs in environmental solid samples; the chemical and electronic properties of PAHs; and the determination of PAHs in drinking water sources.
Download or read book Analysis of Benzopyrenes and Benzopyrene Metabolites by Fluorescence Spectroscopy Techniques written by Bassam Al-Farhani and published by . This book was released on 2016 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt: Polycyclic aromatic hydrocarbons (PAHs) are some of the most common and toxic pollutants encountered worldwide. Presently, monitoring is restricted to sixteen PAHs, but it is well understood that this list omits many toxic PAHs. Among the "forgotten" PAHs, isomers with molecular weight 302 are of particular concern due to their high toxicological properties. The chromatographic analysis of PAHs with MW 302 is challenged by similar retention times and virtually identical mass fragmentation patterns.
Download or read book Polycyclic Aromatic Hydrocarbons in Work Atmospheres written by Alf Bjorseth and published by CRC Press. This book was released on 2018-05-04 with total page 178 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book deals with the sources, distribution, analytical methods, and monitoring of Polycyclic aromatic hydrocarbons (PAH) in the occupational environment. It is hoped that this book will make a contribution to understanding the formation and determination of PAH in work atmosphere and that it will make a particular contribution to occupational health projects. Much of the information given in this book has been generating in studies carried out in cooperation with the Norwegian aluminium industry.
Download or read book The Influence of PAH Concentration and Distribution on Real Time In Situ Measurements of Petroleum Products in Soils Using Laser Induced Fluorescence written by and published by . This book was released on 1995 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Real-time laser induced fluorescence (LIF) in situ measurements of soil samples provide a reliable and cost-effective screening tool for hydrocarbon site assessments. The site characterization and analysis penetrometer system (SCAPS), is a truck-mounted cone penetrometer probe modified with a sapphire window and connected to a laser by fiber optics. The pulsed nitrogen laser 337-nm excitation source induced fluorescence in polynuclear aromatic hydrocarbons (PAHs), which are present in petroleum products. The fluorescence response of these compounds is measured with a fluorometer. The SCAPS can provide continuous hydrocarbon screening measurements to soil depths greater than 100 feet. Discrete soil samples collected from SCAPS boreholes were extracted and analyzed for total petroleum hydrocarbons (TPH), by gas chromatography with flame ionization detection (GC/FID), and 16 parent and over 100 alkyl substituted PAH compounds by gas chromatography with mass spectrometry detection (GC/MS). This method provides a basis for evaluating the relationship between TFH and PAH concentrations in the soil samples and laser induced fluorescence measurements from the soil borings.
Download or read book Polynuclear Aromatic Hydrocarbons written by Marcus Cooke and published by . This book was released on 1985 with total page 1528 pages. Available in PDF, EPUB and Kindle. Book excerpt: Symposium with over one hundred presentations was highlighted by overviews of the complex nature of PAH and their interaction with the environment and the human population that must live within it. New approaches and techniques for measuring PAH were discussed as were the fate of these compounds in the environment. Papers were presented defining the altered biological responses that were induced by PAH species. In some cases the newly defined, substituted PAH had greater effects than the parent compound. Several reports concentrated on the synthesis of derivative PAH species and the actual formation processes that occur in the combustion of fossil fuels.
