Interpreting comprehensive two-dimensional gas chromatography using peak topography maps with application to petroleum forensics

© The Author(s), 2016. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Chemistry Central Journal 10 (2016): 75, doi:10.1186/s13065-016-0211-y.Comprehensive two-dimensional gas chromatography (GC×GC) provides high-resolution separations across hundreds of compounds in a complex mixture, thus unlocking unprecedented information for intricate quantitative interpretation. We exploit this compound diversity across the (GC×GC) topography to provide quantitative compound-cognizant interpretation beyond target compound analysis with petroleum forensics as a practical application. We focus on the (GC×GC) topography of biomarker hydrocarbons, hopanes and steranes, as they are generally recalcitrant to weathering. We introduce peak topography maps (PTM) and topography partitioning techniques that consider a notably broader and more diverse range of target and non-target biomarker compounds compared to traditional approaches that consider approximately 20 biomarker ratios. Specifically, we consider a range of 33–154 target and non-target biomarkers with highest-to-lowest peak ratio within an injection ranging from 4.86 to 19.6 (precise numbers depend on biomarker diversity of individual injections). We also provide a robust quantitative measure for directly determining “match” between samples, without necessitating training data sets. We validate our methods across 34 (GC×GC) injections from a diverse portfolio of petroleum sources, and provide quantitative comparison of performance against established statistical methods such as principal components analysis (PCA). Our data set includes a wide range of samples collected following the 2010 Deepwater Horizon disaster that released approximately 160 million gallons of crude oil from the Macondo well (MW). Samples that were clearly collected following this disaster exhibit statistically significant match (99.23±1.66)% using PTM-based interpretation against other closely related sources. PTM-based interpretation also provides higher differentiation between closely correlated but distinct sources than obtained using PCA-based statistical comparisons. In addition to results based on this experimental field data, we also provide extentive perturbation analysis of the PTM method over numerical simulations that introduce random variability of peak locations over the (GC×GC) biomarker ROI image of the MW pre-spill sample (sample #1 in Additional file 4: Table S1). We compare the robustness of the cross-PTM score against peak location variability in both dimensions and compare the results against PCA analysis over the same set of simulated images. Detailed description of the simulation experiment and discussion of results are provided in Additional file 1: Section S8. We provide a peak-cognizant informational framework for quantitative interpretation of (GC×GC) topography. Proposed topographic analysis enables (GC×GC) forensic interpretation across target petroleum biomarkers, while including the nuances of lesser-known non-target biomarkers clustered around the target peaks. This allows potential discovery of hitherto unknown connections between target and non-target biomarkers.This research was made possible in part by a grant from the Gulf of Mexico Research Initiative (GoMRI-015), and the DEEP-C consortium, and in part by NSF Grants OCE-0969841 and RAPID OCE-1043976 as well as a WHOI interdisciplinary study award

NIOSH manual of analytical methods (NMAM), 5th edition

The National Institute for Occupational Safety and Health (NIOSH) is the U.S. federal agency responsible for conducting research and making recommendations for the prevention of workrelated injury and illness. NIOSH is part of the Centers for Disease Control and Prevention (CDC) in the U.S. Department of Health and Human Services. The NIOSH Manual of Analytical Methods (NMAM) is a compilation of validated sampling and analytical methods that are used globally for occupational exposure assessment in the industrial (occupational) hygiene field and related professions. The methods that are published in NMAM are evaluated and validated in consideration of their fitness-for-purpose for exposure monitoring in work areas. NIOSH methods primarily address workplace air sampling and analysis, but NMAM also includes protocols for biological, surface, dermal, and bulk samples. Within NMAM, but separate from the methods themselves, are assorted chapters providing background and guidance covering a number of subjects. Explanatory chapters on quality assurance, sampling guidance, method development and evaluation, aerosol collection, etc., provide valuable information to users of NIOSH methods. NMAM chapters provide a convenient resource that augments technical information often (but not always) available elsewhere in texts and monographs. Now in its fifth edition, NMAM is continuously updated as new or revised methods are evaluated and their performance verified.This document is a compilation of its guidance chapters and methods, current as of the date shown on the front page. NMAM is published online on the NIOSH web page (www.cdc.gov/niosh/nmam) and is available worldwide free of charge. Users are encouraged to visit the NMAM 5th edition website for the most current methods and guidance chapters.This document is current as of the publication date above [February 2020] and will be periodically updated. For the most current listing of methods and guidance chapters, please visit the NMAM website at www.cdc.gov/niosh/nmam.https://www.cdc.gov/niosh/nmam/pdf/NMAM_5thEd_EBook-508-final.pdf20201077

NIOSH manual of analytical methods (NMAM), 5th edition

This document is current as of the publication date above and will be periodically updated. For the most current listing of methods and guidance chapters, please visit the NMAM website at www.cdc.gov/niosh/nmam.The National Institute for Occupational Safety and Health (NIOSH) is the U.S. federal agency responsible for conducting research and making recommendations for the prevention of work- related injury and illness. NIOSH is part of the Centers for Disease Control and Prevention (CDC) in the U.S. Department of Health and Human Services. The NIOSH Manual of Analytical Methods (NMAM) is a compilation of validated sampling and analytical methods that are used globally for occupational exposure assessment in the industrial (occupational) hygiene field and related professions. The methods that are published in NMAM are evaluated and validated in consideration of their fitness-for-purpose for exposure monitoring in work areas. NIOSH methods primarily address workplace air sampling and analysis, but NMAM also includes protocols for biological, surface, dermal, and bulk samples. Within NMAM, but separate from the methods themselves, are assorted chapters providing background and guidance covering a number of subjects. Explanatory chapters on quality assurance, sampling guidance, method development and evaluation, aerosol collection, etc., provide valuable information to users of NIOSH methods. NMAM chapters provide a convenient resource that augments technical information often (but not always) available elsewhere in texts and monographs. Now in its fifth edition, NMAM is continuously updated as new or revised methods are evaluated and their performance verified.This document is a compilation of its guidance chapters and methods, current as of the date shown on the front page. NMAM is published online on the NIOSH web page (www.cdc.gov/niosh/nmam) and is available worldwide free of charge. Users are encouraged to visit the NMAM 5th edition website for the most current methods and guidance chapters.NMAM_5thEd_EBook-508-final.pdf2020917

Deep Underground Science and Engineering Laboratory - Preliminary Design Report

The DUSEL Project has produced the Preliminary Design of the Deep Underground Science and Engineering Laboratory (DUSEL) at the rehabilitated former Homestake mine in South Dakota. The Facility design calls for, on the surface, two new buildings - one a visitor and education center, the other an experiment assembly hall - and multiple repurposed existing buildings. To support underground research activities, the design includes two laboratory modules and additional spaces at a level 4,850 feet underground for physics, biology, engineering, and Earth science experiments. On the same level, the design includes a Department of Energy-shepherded Large Cavity supporting the Long Baseline Neutrino Experiment. At the 7,400-feet level, the design incorporates one laboratory module and additional spaces for physics and Earth science efforts. With input from some 25 science and engineering collaborations, the Project has designed critical experimental space and infrastructure needs, including space for a suite of multidisciplinary experiments in a laboratory whose projected life span is at least 30 years. From these experiments, a critical suite of experiments is outlined, whose construction will be funded along with the facility. The Facility design permits expansion and evolution, as may be driven by future science requirements, and enables participation by other agencies. The design leverages South Dakota's substantial investment in facility infrastructure, risk retirement, and operation of its Sanford Laboratory at Homestake. The Project is planning education and outreach programs, and has initiated efforts to establish regional partnerships with underserved populations - regional American Indian and rural populations

Stable Isotopes in Tree Rings

This Open Access volume highlights how tree ring stable isotopes have been used to address a range of environmental issues from paleoclimatology to forest management, and anthropogenic impacts on forest growth. It will further evaluate weaknesses and strengths of isotope applications in tree rings. In contrast to older tree ring studies, which predominantly applied a pure statistical approach this book will focus on physiological mechanisms that influence isotopic signals and reflect environmental impacts. Focusing on connections between physiological responses and drivers of isotope variation will also clarify why environmental impacts are not linearly reflected in isotope ratios and tree ring widths. This volume will be of interest to any researcher and educator who uses tree rings (and other organic matter proxies) to reconstruct paleoclimate as well as to understand contemporary functional processes and anthropogenic influences on native ecosystems. The use of stable isotopes in biogeochemical studies has expanded greatly in recent years, making this volume a valuable resource to a growing and vibrant community of researchers