Download or read book Analysis of Polycyclic Aromatic Hydrocarbons in Water by Sep pak Cartridges Coupled with High Performance Liquid Chromatography written by Roger D. Sinram and published by . This book was released on 1980 with total page 102 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Masters Theses in the Pure and Applied Sciences written by Wade Shafer and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 335 pages. Available in PDF, EPUB and Kindle. Book excerpt: Masters Theses in the Pure and Applied Sciences was first conceived, published, and disseminated by the Center for Information and Numerical Data Analysis and Synthesis (CINDAS) * at Purdue University in 1957, starting its coverage of theses with the academic year 1955. Beginning with Volume 13, the printing and dissemination phases of the activity were transferred to University Microfilms/Xerox of Ann Arbor, Michigan, with the thought that such an arrangement would be more beneficial to the academic and general scientific and technical community. After five years of this joint undertaking we had concluded that it was in the interest of all con cerned if the printing and distribution of the volume were handled by an international publishing house to assure improved service and broader dissemination. Hence, starting with Volume 18, Masters Theses in the Pure and Applied Sciences has been disseminated on a worldwide basis by Plenum Publishing Cor poration of New York, and in the same year the coverage was broadened to include Canadian universities. All back issues can also be ordered from Plenum. We have reported in Volume 26 (thesis year 1981) a total of 11 ,048 theses titles from 24 Canadian and 21 8 United States universities. We are sure that this broader base for these titles reported will greatly enhance the value of this important annual reference work. While Volume 26 reports theses submitted in 1981, on occasion, certain univer sities do report theses submitted in previous years but not reported at the time.
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 Investigations Into the Extraction and the Determination of Polycyclic Aromatic Hydrocarbons PAHs from Water by Solid phase Extraction and Capillary Gas Chromatography Mass Spectrometry written by Mohamed Elrutb and published by . This book was released on 1993 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Factors affecting the detennination of PAHs by capillary GC/MS were studied. The effect of the initial column temperature and the injection solvent on the peak areas and heights of sixteen PAHs, considered as priority pollutants, USillg crosslinked methyl silicone (DB!) and 5% diphenyl, 94% dimethyl, 1% vinyl polysiloxane (DBS) columns was examined. The possibility of using high boiling point alcohols especially butanol, pentanol, cyclopentanol, and hexanol as injection solvents was investigated. Studies were carried out to optimize the initial column temperature for each of the alcohols. It was found that the optimum initial column temperature is dependent on the solvent employed. The peak areas and heights of the PAHs are enhanced when the initial column temperature is 10-20 c above the boiling point of the solvent using DB5 column, and the same or 10 C above the boiling point of the solvent using DB1 column. Comparing the peak signals of the PAHs using the alcohols, p-xylene, n-octane, and nonane as injection solvents, hexanol gave the greatest peak areas and heights of the PAHs particularly the late-eluted peaks. The detection limits were at low pg levels, ranging from 6.0 pg for fluorene t9 83.6 pg for benzo(a)pyrene. The effect of the initial column temperature on the peak shape and the separation efficiency of the PARs was also studied using DB1 and DB5 columns. Fronting or splitting of the peaks was obseIVed at very low initial column temperature. When high initial column temperature was used, tailing of the peaks appeared. Great difference between DB! and.DB5 columns in the range of the initial column temperature in which symmetrical.peaks of PAHs can be obtained is observed. Wider ranges were shown using DB5 column. Resolution of the closely-eluted PAHs was also affected by the initial column temperature depending on the stationary phase employed. In the case of DB5, only the earlyeluted PAHs were affected; whereas, with DB1, all PAHs were affected. An analytical procedure utilizing solid phase extraction with bonded phase silica (C8) cartridges combined with GC/MS was developed to analyze PAHs in water as an alternative method to those based on the extraction with organic solvent. This simple procedure involved passing a 50 ml of spiked water sample through C8 bonded phase silica cartridges at 10 ml/min, dried by passing a gentle flow of nitrogen at 20 ml/min for 30 sec, and eluting the trapped PAHs with 500 Jll of p-xylene at 0.3 ml/min. The recoveries of PAHs were greater than 80%, with less than 10% relative standard deviations of nine determinations. No major contaminants were present that could interfere with the recognition of PAHs. It was also found that these bonded phase silica cartridges can be re-used for the extraction of PAHs from water.
Download or read book Method Development and Monitoring of Polynuclear Aromatic Hydrocarbons in Selected U S Waters written by Jitendra Saxena and published by . This book was released on 1977 with total page 100 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 Analysis of Polycyclic Aromatic Hydrocarbons in Tobacco Related Samples Via High Performance Liquid Chromatography and Laser Excited Time Resolved Shpol Skii Spectroscopy written by Ahmed Comas and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Human exposure to polycyclic aromatic hydrocarbons (PAHs) due to cigarette smoke is well known. It is also known that PAHs are not inherent components of tobacco. Their presence in cigarette smoke results from the curing process of tobacco leaves used for the fabrication of cigarettes and the incomplete combustion of tobacco during the smoking process. The two chromatographic versions of EPA method 610 are popular approaches for the analysis of PAHs in a wide variety of samples. This method, which is based either on High-Performance Liquid-Chromatography (HPLC) or Gas-Chromatography (GC) has shown the presence of Benzo[a]pyrene (B[a]P) in tobacco samples and cigarette smoke. B[a]P is the most toxic PAH in the U.S Environmental Protection Agency (EPA) priority pollutant list.
Download or read book Journal of Chromatography written by and published by . This book was released on 1995 with total page 986 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Novel Improvements on the Analytical Chemistry of Polycyclic Aromatic Hydrocarbons and Their Metabolites written by Wang Huiyong and published by . This book was released on 2010 with total page 232 pages. Available in PDF, EPUB and Kindle. Book excerpt: Polycyclic aromatic hydrocarbons (PAH) are important environmental pollutants originating from a wide variety of natural and anthropogenic sources. Because many of them are highly suspect as etiological agents in human cancer, chemical analysis of PAH is of great environmental and toxicological importance. Current methodology for PAH follows the classical pattern of sample preparation and chromatographic analysis. Sample preparation pre-concentrates PAH, simplifies matrix composition, and facilitates analytical resolution in the chromatographic column. Among the several approaches that exist to pre-concentrate PAH from water samples, the Environmental Protection Agency (EPA) recommends the use of solid-phase extraction (SPE). High-performance liquid chromatography (HPLC) and gas chromatography-mass spectrometry (GC-MS) are the basis for standard PAH identification and determination. Ultraviolet (UV) absorption and room temperature fluorescence detection are both widely used in HPLC, but the specificity of these detectors is modest. Since PAH identification is solely based on retention times, unambiguous PAH identification requires complete chromatographic resolution of sample components. When HPLC is applied to "unfamiliar" samples, the EPA recommends that a supporting analytical technique such as GC-MS be applied to verify compound identification and to check peak-purity HPLC fractions. Independent of the volume of extracted water, the approximate time required to separate and determine the sixteen "priority pollutants" (EPA-PAH) via HPLC is approximately 60min. If additional GC-MS analysis is required for unambiguous PAH determination, the total analysis time will reach 2-3 hours per sample. If the concentrations of target species are found to lie outside the detector's response range, the sample must be diluted and the process repeated. These are important considerations when routine analysis of numerous samples is contemplated. Parent PAH are relatively inert and need metabolic activation to express their carcinogenicity. By virtue of the rich heterogeneous distribution of metabolic products they produce, PAH provide a full spectrum of the complexity associated with understanding the initial phase of carcinogenesis. PAH metabolites include a variety of products such as expoxides, hydroxyl aromatics, quinines, dihydrodiols, dioepoxides, tetrols and water soluble conjugates. During the past decades tremendous efforts have been made to develop bio-analytical techniques that possess the selectivity and sensitivity for the problem at hand. Depending on the complexity of the sample and the relative concentrations of the targeted metabolites, a combination of sample preparation techniques is often necessary to reach the limits of detection of the instrumental method of analysis. The numerous preparation steps open ample opportunity to metabolite loss and collection of inaccurate data. Separation of metabolites has been accomplished via HPLC, capillary electrophoresis (CE) and GC-MS. Unfortunately, the existence of chemically related metabolic products with virtually identical fragmentation patterns often challenges the specificity of these techniques. This dissertation presents significant improvements in various fronts. Its first original component--which we have named solid-phase nano-extraction (SPNE)--deals with the use of gold nanoparticles (Au NPs) as extracting material for PAH. The advantages of SPNE are demonstrated for the analysis of PAH in water samples via both HPLC and Laser-Excited Time-Resolved Shpol'skii Spectroscopy (LETRSS). The same concept is then extended to the analysis of monohydroxy-PAH in urine samples via SPE- HPLC and In-Capillary SPNE-CE. The second original component of this dissertation describes the application of Shpol'skii Spectroscopy to the analysis of polar PAH metabolites. The outstanding selectivity and sensitivity for the direct analysis of PAH at trace concentration levels has made Shpol'skii spectroscopy a leading technique in environmental analysis. Unfortunately, the requirement of a specific guest-host combination--typically a non-polar PAH dissolved in an n-alkane-- has hindered its widespread application to the field of analytical chemistry. This dissertation takes the first steps in removing this limitation demonstrating its feasibility for the analysis of polar benzopyrene metabolites in alcohol matrixes.
Download or read book Handbook of Analytical and Spectral Data for Polycyclic Aromatic Hydrocarbons Benzo a pyrene and its metabolites written by and published by . This book was released on 1993 with total page 322 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Identification and Quantitation of Complex Polycyclic Aromatic Hydrocarbon Mixtures in Environmental Samples Using Comprehensive Two dimensional Gas Chromatography with Time of flight Mass Spectrometry written by Carlos Andres Manzano and published by . This book was released on 2012 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt: Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous contaminants and are mostly products of the incomplete combustion of organic material. PAHs are often found in environmental samples as a complex mixture of isomers. In addition, the same sources that produce complex PAH mixtures also produce other poorly characterized mixtures of organic compounds, commonly referred to as an unresolved complex mixture (UCM), that act as matrix interferences in the chromatographic analysis of samples. Conventional one-dimensional chromatographic techniques, such as gas chromatography coupled to mass spectrometry (GC/MS), are not sufficient for the analysis and quantitation of complex PAH mixtures present in environmental samples due to the high degree of overlap in compound vapor pressures, boiling points, and mass spectral fragmentation patterns. Therefore, the separation and quantitation of complex mixtures of individual PAH compounds in environmental samples requires high chromatographic resolution. Comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GCxGC/ToF-MS) was used for this study. GCxGC/ToF-MS uses two different gas chromatographic columns, with different separation mechanisms, for the analysis of complex environmental samples. In theory, the peak capacity in GCxGC/ToF-MS is equivalent to the product of the individual peak capacities of each column used. However, in practice, this is rarely obtained because of the existing correlation between the two GC columns used. This dissertation is a compilation of three studies related to analytical method development for the identification and quantitation of complex PAH mixtures (including parent-PAHs, alkyl-PAHs, oxy-PAHs, nitro-PAHs, thio-PAHs, chloro-PAHs, bromo-PAHs and PAHs with molecular weight higher than 300 Da) that may be present in environmental samples using novel column combinations in GCxGC/ToF-MS. The use of a liquid crystal column (LC-50) in the first dimension, followed by a nano-stationary phase column (NSP-35) in the second dimension, was evaluated for the separation of a standard PAH mixture containing 97 different PAHs. Two standard reference materials purchased from NIST (NIST SRM1650b - Diesel Particulate Matter and NIST SRM1975 - Diesel Extract) were used, after extraction and cleanup, for method validation and comparison between the commonly used non-polar x polar column combination and the LC-50 x NSP-35 column combination with high orthogonality. As part of the method validation, an aliquot of NIST SRM1975 (Diesel extract), without sample cleanup was also analyzed for PAHs, showing that the LC-50 x NSP-35 column combination was accurate (with an average absolute percent difference of approximately 30%) for the identification and quantitation of complex PAH mixtures in environmental samples, with reduced sample preparation prior to analysis. In addition, the LC-50 x NSP-35 column combination was used for the analysis of PAHs sorbed to polystyrene pellets deployed in an urban bay area as passive water samplers because one-dimensional GC/MS was ineffective due to the presence of a strong unresolved complex mixture (UCM) and matrix interferences.
Download or read book Polycyclic Aromatic Hydrocarbons written by and published by National Academies Press. This book was released on 1983-01-01 with total page 482 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Selected Water Resources Abstracts written by and published by . This book was released on 1991 with total page 808 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Polycyclic Aromatic Hydrocarbons in Water Sys written by David J. Futoma and published by Springer. This book was released on 1981-11-05 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt: Opisane so spektroskopske in kromatografske analize PAH v vodi, njihova topnost, vzorčevanje in predhodno koncentriranje.
Download or read book Determination of Polycyclic Aromatic Hydrocarbons in Water Samples by Using High Performance Liquid Chromatography written by Ruchaya Boonyatumanond and published by . This book was released on 1999 with total page 258 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Handbook of Polycyclic Aromatic Hydrocarbons written by Alf Bjørseth and published by . This book was released on 1983 with total page 440 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Determination of Organic Compounds in Natural and Treated Waters written by T R Crompton and published by CRC Press. This book was released on 1999-10-14 with total page 929 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive reference which draws together and systematises the information available on the occurrence and determination of organic substances in all types of non-saline and saline natural and treated waters. It provides a comprehensive description of organic compounds in all natural and treated water types. The book includes a series of table
