Download or read book Characterization and Implementation of Analytical Methods for Dioxin Analysis written by Conner Stultz and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Polychlorinated dibenzo-p-dioxins and dibenzofurans, commonly called dioxins, have been compounds of concern for decades. Dioxins, along with polychlorinated biphenyls (PCBs) and polychlorinated naphthalenes (PCNs), are considered persistent organic pollutants or POPs. Dioxins, PCBs, and PCNs are halogenated aromatic compounds, and all three compounds pose similar toxicological concerns to animals. As the name POPs suggests, these compounds are known to be chemically stable in the environment and bioaccumulate in animals. There are numerous studies on the health effects of dioxins, PCBs, and PCNs in a variety of organisms. However, the low concentrations of these compounds found in the environment and their bio-accumulative effects raise concerns over chronic, rather than acute, health issues. The analysis of dioxins, PCBs, and PCNs is challenging due to their low concentration detection requirements, hundreds of possible congeners, and complicated sample matrix. Due to these challenges, the analysis of these compounds is generally performed by gas chromatography coupled to mass spectrometry (GC-MS). There are extensive studies published on the analysis of PCBs and dioxins on a variety of GC separation columns as well as studies on detection limits of the instrumentation used. However, there has been little focus on defining instrument performance, column selectivity, and identifying coelutions on various column phases, which is the goal of the following studies. Traditionally, dioxin analysis has been performed by gas chromatography coupled to a high-resolution mass spectrometer (GC-HRMS). GC-HRMS has historically provided the selectivity and sensitivity necessary to analyze dioxins; however, they are limited by the number of compounds they can monitor for at a time and are larger than newer benchtop models. Additionally, HRMS instruments are being phased out, due to issues with the metals used in the construction of the magnets. Benchtop mass spectrometers such as triple quadrupoles (MS/MS), quadrupole time of flight (Q-TOF), and TOF instruments are potentially capable of the same selectivity and sensitivity as the GC-HRMS system. These instruments offer advantages in the number of compounds that can be monitored for at a time and ease of use over the GC-HRMS. However, even with the advantages provided by these newer instruments, the GC-HRMS is still singled out as the instrument of choice in regulatory methods. A comparison was made between the GC-HRMS and five benchtop instruments with a method detection limit study to show that these newer instruments are capable of the same selectivity and sensitivity as the GC-HRMS system and can be used for regulatory dioxin analysis. Instrument sensitivity is an important factor in dioxin, PCB, and PCN analysis as these compounds are found at trace levels in the environment and animals. However, selectivity for these compounds is just as important a consideration as sensitivity. Dioxins have a possible 5020 unique congeners. That number includes the 210 chlorinated dioxins, 17 of which are considered toxic, 210 brominated dioxins, and 4600 mixed chlorinated/brominated compounds. PCBs have 209 chlorinated congeners, and PCNs have a possible 75 chlorinated congeners. Selecting the correct stationary phase is essential to characterize the toxicity of a sample accurately, as many of the congeners coelute. Nine popular GC columns were characterized for their ability to separate dioxins, PCBs, and PCNs using a retention index system. The retention index values for two columns were plotted against each other to obtain a selectivity graph. These graphs can be used to identify which columns provide the most significant selectivity difference for the compounds of interest. The retention indices generated also serve as a secondary means of analyte identification. These graphs were then used to identify a unique confirmation column pair for use with UESPA method 1613. The Rxi-17SilMS and Rtx-Dioxin2 columns showed unique selectivity for dioxins that can be used to fulfill the requirements of the USEPA-1613 method. Finally, this column combination is used with comprehensive 2-dimensional chromatography to develop a single analytical method to separate the toxic dioxin congeners from other dioxins and interfering compounds. The following research presented in chapters 2-6 has all been submitted for peer-reviewed publication. Chapter 2 has been published in the Journal of Mass Spectrometry. Chapter 3 has been published in the Journal of Chromatography A. Chapters 4, 5, and 6 are currently under peer review for publication in the Journal of Chromatography A. I directly contributed to all the research presented in this dissertation and am listed as the first author on all publications.

Download or read book Dioxins Analytical method for industrial wastes written by and published by . This book was released on 1980 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Harmonizing Methods for the Determination of Dioxins in Food written by and published by Nordic Council of Ministers. This book was released on 2007 with total page 70 pages. Available in PDF, EPUB and Kindle. Book excerpt: Methods for sampling and sample treatment as well as the analytical methodology for determination of dioxin and dioxin-like PCBs in food have been discussed and evaluated at 2 workshops with participation from all Nordic countries. It was found that in general the EU regulation and guidelines for sampling and sample treatment appears to fit their purpose although there is a need for better procedures for the sampling of lots containing fishes of different size or weight. Information on the equipment and analytical methods used by the Nordic dioxin laboratories to measure dioxin and dioxin-like PCB in foodstuffs were compiled through a questionnaire. Together the replies are giving an overview of the analytical capacity in the Nordic countries and they demonstrate that the analytical methodology used by the Nordic dioxin laboratories is in good agreement with the EU guidelines and other international standards and recommendations.

Download or read book Dioxin Perspectives written by Erich W. Bretthauer and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 785 pages. Available in PDF, EPUB and Kindle. Book excerpt: Erich W. Bretthauer, Chairman of the Exposure and Hazard Assessment Working Group U. s. Environmental Protection Agency Washington, D. C. The efforts of the Exposure and Hazard Assessment Working Group were focused on the exchange of information on a variety of topics including research projects, regulations/statutes, analytical laboratories, and methods of exposure/risk assessment involving CDDs and CDFs. It was evident to the leaders of the Working Group that several of the knowledge voids had to be addressed on a fundamental level before expanded efforts could be made. Several questions needed to be answered: • Who has done research on this topic, and what do the data indicate? • Who is performing research now, and what are their capabilities? • How are other nations addressing this problem, and do they have legislative mandates in place? • Is there a general consensus on the topic? The members of the Working Group believed that these questions could be answered by surveying the major participants in the field of interest. Three principal survey efforts were performed by the Working Group, which collected information on research, regulations/statutes, and analytical laboratories from each of the participating nations. In addition to answering these fundamental questions, these efforts also fulfilled the major objectives of the entire Pilot Study. The collection, analysis, and distribution of information on research projects, regulations/statutes, and analytical laboratories were very useful efforts in helping to fill some of the basic knowledge voids.

Download or read book Decades of Dioxin written by Warren B. Crummett and published by Xlibris Corporation. This book was released on 2002 with total page 345 pages. Available in PDF, EPUB and Kindle. Book excerpt: By 1971 analytical scientists at Dow had good reason to believe that questions about "dioxin" (2,3,7,8-dibenzo-p-dioxin) had been appropriately addressed. This molecule had been identified as an unwanted trace contaminant in 2,4,5-trichlorophenol and its derivatives; synthesized and analytical standards prepared; characterized by all the known measurement techniques; and controlled in Dow products by newly developed analytical methods of confirmed integrity at levels 10 times lower than deemed necessary by Dow toxicologists. Thus we had not only fulfilled all the requirements of government agencies, we had gone the extra mile. No other product contaminant had been treated so rigorously. There was no doubt that Dow products were safe when used as directed. Once again we had proven that molecules could be successfully managed. Although there was already some noise decrying this conclusion, we were totally unprepared to weather the brouhaha which developed. "Dioxin" appeared to be a molecule that created fear and caused people to do strange (unscientific) things. Was it more than just a molecule? We now turned our attention to measuring the amount of "dioxin" in the environment. We were well prepared to develop methodology to do this. We had state-of-the-art equipment and some of the best chromatographers and mass spectroscopists in the world. We were confident we could find and measure "dioxin" (if present) in any matrix of interest at appropriate detection levels. Then we could determine how the dioxin got there and discover ways to completely control and manage the presence and movement of this molecule in the environment. This was our perception! This perception was reinforced by the merger of Dow analytical laboratories. For the first time powerful measurement tools would be under the same management as the separation systems. This created many opportunities for spectroscopists, chromatographers and instrument development folks to do extraordinary things together. The resulting laboratory, consisting of almost 200 technical people, was managed by a technical director and a technical manager. I was named technical manager, a position without a job description. We were not, however, positioned to communicate effectively with the world outside Dow. Those of us working in trace analysis had neither published much nor attended many scientific meetings outside the company. We had not honed either our writing or speaking skills. So our papers were rejected and we were seldom heard speaking. This took some years to correct as we didn't immediately recognize that we needed to have credibility with our peers in academia, government and other industry. In spite of this naivety on my part, I soon found myself serving on committees, task forces and study groups both within Dow and with government agencies in the United States and Canada. Immediately it became apparent to me that the integrity of analytical data at trace levels was a major problem. Different laboratories used different principles in the interpretation of signals. Consensus on data interpretation needed to be reached. But of even greater importance was the need to communicate with journalists. Each encounter with peers and others interested in "dioxin" became a great adventure filled with fun. Often these meetings were humorous, always challenging, sometimes testy scientists from industry always were portrayed as biased and even incompetent. So, "dioxin" appeared to cause people to do strange things. By means of anecdotal stories and essays this book attempts to convey the principal scientific and philosophical lessons learned, as well as reveal the astonishing behavior of those contributing to the frustration, agony and elation experienced by this industrial analytical chemist. Among the surprising lessons learned are: 1. Fear can create big business. 2. In a "crisis" situation, even

Download or read book Comprehensive Two dimensional Chromatographic Techniques for Ultra trace Quantitative Analysis of Chlorinated Dioxins in South Africa written by Betty-Jayne de Vos and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) are toxic environmental pollutants formed as by-products of industrial and thermal processes. They are chlorinated compounds that have similar structures and chemical properties that were included in the original United Nations Environment Programme’s ‘dirty dozen’ and now form part of the Stockholm Convention (SC) on Persistent Organic Pollutants (POPs). As a signatory to the Stockholm Convention, South Africa has the obligation to undertake appropriate research, monitoring, and cooperation pertaining to POPs, and more particularly, PCDD/Fs. Currently there is no established PCDD/F laboratory in South Africa capable of these demanding measurements and alternative approaches must be considered that are more affordable, more robust and more user friendly for a developing economy. PCDD/Fs are highly toxic, causing a myriad of negative human health effects such as chloracne, carcinogenicity, hepatotoxicity, teratogenicity, endocrine disruption and alterations in neural development. The toxicity of PCDD/Fs is mediated through the aryl hydrocarbon receptor (AhR). PCDD/Fs bind to the AhR and elicit an AhR-mediated biochemical and toxic response. The in-depth information available on the mechanism of toxicity also allows for PCDD/Fs to be analysed using the AhR receptor mediated response in genetically modified cell lines. This led to the development of a bio-analytical screening technique using in vitro H4IIE-luc reporter gene bio-assay for AhR active compounds for the initial screening of PCDD/Fs in soil and sediment. The intension in this study was to develop an integrated approach to the analysis of PCDD/Fs in the South African environment, considering the associated cost as well as the available instrumentation, expertise and relevance within a developing economy. Historically, the quantitative confirmatory analysis of these compounds has been achieved by targeted analysis using gas chromatography coupled with high-resolution magnetic sector mass spectrometry instruments (GC-HRMS), the accepted benchmark technology used for determining the level of trace organic environmental contaminants such as PCDD/Fs. However, these methods are time consuming and expensive. Advances in technology have led to comprehensive two-dimensional gas chromatography - time-of-flight mass spectrometry (GC×GC-TOFMS) methodology that can be used for the analysis of PCDD/Fs in samples with different matrices. This approach is well suited for application in developing economies where access to GC-HRMS and highly skilled personnel is limited. This thesis describes the bio-analytical technique and the method development and analysis of the seventeen toxic PCDD/F congeners using GC×GC-TOFMS methodology. The technique provides the selectivity (added peak capacity of GC×GC) and the sensitivity (focusing effect of the modulator) needed to meet the requirements as mandated for analysis in US EPA Method 1613B. Extracted samples analysed on a GC-HRMS instrument, were re-analyzed using the low-resolution GC×GC-TOFMS instrument and the results confirmed using a high resolution TOF mass spectrometer (HRT). The quantitative results obtained compare well with those obtained using GC-HRMS. Because GC×GC-TOFMS is not a target compound analytical technique (as is GC-HRMS), it is possible to obtain information on numerous other classes of organic pollutants present in the samples in one analytical run, although this information can be sample clean-up dependant. Preliminary validation of the GC×GC-TOFMS method is investigated using a certified reference material and real South African soil samples. The South African soil samples studied showed extremely high levels of PAHs, aliphatic hydrocarbons and sulphur. The organic content and matrix interference of South African soil samples (and the NIST standard reference material sediment; SRM 1944) provided significant challenges for the validation study. This study has shown that GC×GC-TOFMS provides a quick, convenient screen for numerous pollutant classes which may be present in environmental samples. Retrospective data mining of archived data (extraction dependant) is possible and has provided key information on other chlorinated and brominated contaminants present in South African waste, soil and sediment samples. NMISA now has a viable GC×GC-TOFMS dioxin analytical method for low level (ultra-trace) quantitative screening of chlorinated compounds that can be offered to South African analytical laboratories for routine dioxin analysis. The work is relevant scientifically and is a definitive contribution to the growing compilation of GC×GC methodology, providing efficient methods for this demanding environmental application.

Download or read book National Dioxin Study written by U. S. Environmental Protection Agency and published by BiblioGov. This book was released on 2013-07 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt: The U.S. Environmental Protection Agency (EPA) was introduced on December 2, 1970 by President Richard Nixon. The agency is charged with protecting human health and the environment, by writing and enforcing regulations based on laws passed by Congress. The EPA's struggle to protect health and the environment is seen through each of its official publications. These publications outline new policies, detail problems with enforcing laws, document the need for new legislation, and describe new tactics to use to solve these issues. This collection of publications ranges from historic documents to reports released in the new millennium, and features works like: Bicycle for a Better Environment, Health Effects of Increasing Sulfur Oxides Emissions Draft, and Women and Environmental Health.

Download or read book Framework for Application of the Toxicity Equivalence Methodology for Polychlorinated Dioxins Furans and Biphenyls in Ecological Risk Assessment written by and published by . This book was released on 2008 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book EPA Publications Bibliography written by United States. Environmental Protection Agency and published by . This book was released on 2000-07 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book National Dioxin Study written by and published by . This book was released on 1986 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Techniques for Measurement and Removal of Dioxins and Furans written by Vaishali Shahare and published by CRC Press. This book was released on 2017-11-30 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a well organised treatise on identification and measurement of dioxins and furan in the environment. It focuses on their source, fate, behaviour, analytical techniques for measurement, and removal/control methods. Although there are numerous publications that address this subject, rarely are prevention and control concepts considered together in a single volume. This book provides a tool for today's environmental researchers by focusing on an integrated approach to managing environmental pollution problems due to dioxins and furans. The overall objective of this book is not simply to provide a general reference, but to serve as a resource for developing approaches to managing environmental pollution problems due to dioxins and furans.

Download or read book Handbook of Food Science Technology and Engineering 4 Volume Set written by Y. H. Hui and published by CRC Press. This book was released on 2005-12-19 with total page 3632 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advances in food science, technology, and engineering are occurring at such a rapid rate that obtaining current, detailed information is challenging at best. While almost everyone engaged in these disciplines has accumulated a vast variety of data over time, an organized, comprehensive resource containing this data would be invaluable to have. The

Download or read book Federal Register written by and published by . This book was released on 1983-04 with total page 1572 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Harmonizing Methods for the Determination of Dioxins in Food written by Arne Büchert and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Methods for sampling and sample treatment as well as the analytical methodology for determination of dioxin and dioxin-like PCBs in food have been discussed and evaluated at 2 workshops with participation from all Nordic countries. It was found that in general the EU regulation and guidelines for sampling and sample treatment appears to fit their purpose although there is a need for better procedures for the sampling of lots containing fishes of different size or weight. Information on the equipment and analytical methods used by the Nordic dioxin laboratories to measure dioxin and dioxin-like PCB in foodstuffs were compiled through a questionnaire. Together the replies are giving an overview of the analytical capacity in the Nordic countries and they demonstrate that the analytical methodology used by the Nordic dioxin laboratories is in good agreement with the EU guidelines and other international standards and recommendations

Download or read book A Risk Management Strategy for PCB Contaminated Sediments written by National Research Council and published by National Academies Press. This book was released on 2001-06-07 with total page 451 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a risk-based framework for developing and implementing strategies to manage PCB-contaminated sediments at sites around the country. The framework has seven stages, beginning with problem definition, continuing through assessment of risks and management options, and ending with an evaluation of the success of the management strategy. At the center of the framework is continuous and active involvement of all affected parties-particularly communities-in the development, implementation, and evaluation of the management strategy. A Risk-Management Strategy for PCB-Contaminated Sediments emphasizes the need to consider all risks at a contaminated site, not just human health and ecological effects, but also the social, cultural, and economic impacts. Given the controversy that has arisen at many PCB-contaminated sites, this book provides a consistent, yet flexible, approach for dealing with the many issues associated with assessing and managing the risks at Superfund and other contaminated sites.

Download or read book Selected Water Resources Abstracts written by and published by . This book was released on 1987 with total page 656 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Department of Housing and Urban Development independent Agencies Appropriations for 1985 written by United States. Congress. House. Committee on Appropriations. Subcommittee on HUD-Independent Agencies and published by . This book was released on 1984 with total page 1878 pages. Available in PDF, EPUB and Kindle. Book excerpt: