Download or read book Investigations Into the Determination of Polycyclic Aromatic Hydrocarbons PAHs and Polychlorinated Biphenyls PCBs by Capillary Gas Chromatography written by Xing-Fang Li and published by . This book was released on 1989 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Factors involved in the determination of PAHs (16 priority PAHs as an example) and PCBs (10 PCB congeners, representing 10 isomeric groups) by capillary gas chromatography coupled with mass spectrometry (GC/MS, for PAHs) and electron capture detection (GC/ECD , for PCBs) were studied, with emphasis on the effect of solvent. Having various volatilities and different polarities, solvent studied included dichloromethane, acetonitrile, hexan e, cyclohexane, isooctane, octane, nonane, dodecane, benzene, toluene, p-xylene, o-xylene, and mesitylene. Temperatures of the capillary column, the injection port, the GC/MS interface, the flow rates of carrier gas and make-up gas, and the injection volume were optimized by one factor at a time method or simplex optimization method. Under the optimized conditions, both peak height and peak area of 16 PAHs, especially the late-eluting PAHs, were significantly enhanced (1 to 500 times) by using relatively higher boiling point solvents such as p-xylene and nonane, compared with commonly used solvents like benzene and isooctane. With the improved sensitivity, detection limits of between 4.4 pg for naphthalene and 30.8 pg for benzo[g,h,i]perylene were obtained when p-xylene was used as an injection solvent. Effect of solvent on peak shape and peak intensity were found to be greatly dependent on temperature parameters, especially the initial temperature of the capillary column. The relationship between initial temperature and shape of peaks from 16 PAHs and 10 PCBs were studied and compared when toluene, p-xylene, isooctane, and nonane were used as injection solvents. If a too low initial temperature was used, fronting or split of peaks was observed. On the other hand, peak tailing occurred at a too high initial column temperature. The optimum initial temperature, at which both peak fronting and tailing were avoided and symmetrical peaks were obtained, depended on both solvents and the stationary phase of the column used. On a methyl silicone column, the alkane solvents provided wider optimum ranges of initial temperature than aromatic solvents did, for achieving well-shaped symmetrical GC peaks. On a 5% diphenyl: 1% vinyl: 94% dimethyl polysiloxane column, when the aromatic solvents were used, the optimum initial temperature ranges for solutes to form symmetrical peaks were improved to a similar degree as those when the alkanes were used as injection solvents. A mechanism, based on the properties of and possible interactions among the analyte, the injection solvent, and the stationary phase of the capillary column, was proposed to explain these observations. The effect of initial temperature on peak height and peak area of the 16 PAHs and the 10 PCBs was also studied. The optimum initial temperature was found to be dependent on the physical properties of the solvent used and the amount of the solvent injected. Generally, from the boiling point of the solvent to 10 0C above its boiling point was an optimum range of initial temperature at which cthe highest peak height and peak area were obtained.
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 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 written by Elrutb, Mohamed and published by 1993.. This book was released on 1993 with total page 336 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book PAHs written by Peter E. T. Douben and published by John Wiley & Sons. This book was released on 2003-07-25 with total page 404 pages. Available in PDF, EPUB and Kindle. Book excerpt: Polycyclic aromatic hydrocarbons (PAHs), or polyarenes, are one of the largest and most structurally diverse class of organic molecules known. High percentages of polyarenes, representing a wide range of molecular sizes and structural types, are present in coal tars and petroleum residues. The major sources of PAHs are crude oil, coal and oil shale. The fuels produced from these fossil sources constitute the primary source of energy for the industrial nations of the world, and the petrochemicals from these raw materials are the basis of the synthetic fibre and plastics industries. PAHs are however, widespread pollutants and their impact on the environment and human health must be monitored and controlled. This book will review and assess our scientific understanding of the ecological exposure and effects PAHs have in different environments and habitats. It will accomplish this by taking the recipients of the pollution in the environment as starting points and working its way back through pathways to access what is required for our understanding of effects and rationale for control. Although this book will concentrate on ecological exposure of PAHs, the general impacts of PAHs on human populations will be touched upon. It is thought to be the first book to focus on the ecological aspects of PAHs.
Download or read book Determination of Polycyclic Aromatic Hydrocarbons by Gas Chromatography mass Spectrometry and Method Development in Supercritical Fluid Chromatography written by Jari Tuominen and published by . This book was released on 1990 with total page 77 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Polychlorinated Biphenyls PCBs and Polycyclic Aromatic Hydrocarbons PAHs in UK Air and Deposition written by Crispin J. Halsall and published by . This book was released on 1995 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Polychlorinated Biphenyls PCBs and Polycyclic Aromatic Hydrocarbons PAHs in a Rural United Kingdom Lake and Studies on Their Environmental Cycling written by Bondi Gevao and published by . This book was released on 1998 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Publications of the National Institute of Standards and Technology Catalog written by National Institute of Standards and Technology (U.S.) and published by . This book was released on 1992 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Polychlorinated Biphenyls PCBs and Polycyclic Aromatic Hydrocarbons PAHs in UK Air and Deposition written by Crispin J. Halsall and published by . This book was released on 1995 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book PCB in Water written by Water Resources Scientific Information Center and published by . This book was released on 1973 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Determination of Polychlorinated Biphenyls in Open Ocean Waters written by J. C. Duinker and published by . This book was released on 1984 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Core Group's recommendations were adopted at the Fourth Session of GEMSI (Curacao, 25-31 March 1982), and it was further decided that, to increase the cost effectiveness of the proposed six-month activity noted above, a detailed report would be given on the results obtained during the preliminary period with respect to identification of individual PCB components by gas chromatography and gas chromatography-mass spectrometry as well as to the distribution of individual components between solution and particulate matter. This is the subject of this publication. The methods described here are also appropriate for the estimation of several other halogenated hydrocarbons in seawater. Some of these compounds appear in the same fraction as PCB (e.g. penta- and hexa-chlorobenzene); for the estimation of more polar components, additional GC-ECD analyses are required. The extracts needed for this purpose require only relatively small additional steps in the separation procedures.
Download or read book Hydrocarbon Pollution and its Effect on the Environment written by Muharrem Ince and published by BoD – Books on Demand. This book was released on 2019-12-04 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers hydrocarbon pollution, measurement techniques for hydrocarbons, risk assessment, and environmental impact. This comprehensive book takes a broad view of the subject and integrates a wide variety of approaches. This book attempts to address the needs of graduate and postgraduate students and other professionals or readers interested in food, soil, water, and air pollution. The aim of this book is to explain and clarify important studies, and compare and develop the new and groundbreaking measurement techniques. Written by leading experts in their respective areas, the book is highly recommended to professionals interested in environmental and human health because it provides specific and comprehensive examples.
Download or read book Polycyclic aromatic hydrocarbons PAHs and polychlorinated biphenyls PCBs in sediments from the Mersey Estuary U K written by C.H. Vane and published by . This book was released on 2007 with total page 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 Report summaries written by United States. Environmental Protection Agency and published by . This book was released on 1983 with total page 1584 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Development of an On site Gas Chromatography mass Spectrometer for Rapid Detection of Polycyclic Aromatic Hydrocarbons and Polychlorinated Biphenyls at Hazardous Waste Sites written by Brian Michael Abraham and published by . This book was released on 1993 with total page 308 pages. Available in PDF, EPUB and Kindle. Book excerpt:
