Download or read book New Methods for Nitrogen Stable Isotope Measurements of Amino Acids written by Taylor A. B. Broek and published by . This book was released on 2014 with total page 74 pages. Available in PDF, EPUB and Kindle. Book excerpt: Compound specific isotope analysis of individual amino acids (CSI-AA) is a powerful tool for tracing nitrogen (N) source and transformation in biogeochemical cycles. Specifically, the delta15N value of phenylalanine (delta15N Phe) represents an increasingly used proxy for baseline delta15N values, with particular promise for paleoceanographic applications. Further, multiple studies have shown that delta15N values of Phe and glutamic acid (Glu) can be coupled to provide precise estimates of trophic position (TP), while simultaneously decoupling baseline delta15N values from the effects of trophic transfer. However, current derivatization/gas chromatography (GC) methods require expensive and relatively uncommon instrumentation, and have relatively low precision, posing significant issues for many potential applications. Here we present a new approach to CSI-AA based on a high-pressure liquid chromatography (HPLC) purification of underivatized amino acids, followed by offline elemental analysis-isotope ratio mass spectrometry (EA-IRMS). The utility of this approach is demonstrated in two different applications using natural materials: 1) the construction of a high precision paleoceanographic record from the delta15NPhe in proteinaceous coral tissue and 2) the TP estimation of five marine organisms using the coupled delta15N values of Glu and Phe. Both demonstrations were compared to values measured by an established GC based method. In all cases both methods produced equivalent values, however, values generated by the new HPLC/EA-IRMS approach had higher average precision in all cases. These results demonstrate that this approach represents a viable alternative to traditional GC based methods for delta15NAA measurement and may therefore allow significant expansion of CSI-AA applications, requiring only commonly available instrumentation to produce high precision delta15N AA values.
Download or read book Compound specific Stable Isotope Analysis written by Maik A Jochmann and published by Royal Society of Chemistry. This book was released on 2015-11-09 with total page 306 pages. Available in PDF, EPUB and Kindle. Book excerpt: The use of Compound-specific Stable Isotope Analysis (CSIA) is increasing in many areas of science and technology for source allocation, authentication, and characterization of transformation reactions. Until now, there have been no textbooks available for students with an analytical chemical background or basic introductory books emphasising the instrumentation and theory. This book is the first to focus solely on stable isotope analysis of individual compounds in sometimes complex mixtures. It acts as both a lecture companion for students and a consultant for advanced scientists in fields including forensic and environmental science. The book starts with a brief history of the field before going on to explain stable isotopes from scratch. The different ways to express isotope abundances are introduced together with isotope effects and isotopic fractionation. A detailed account of the required technical equipment and general procedures for CSIA is provided. This includes sections on derivatization and the use of microextraction techniques in GC-IRMS. The very important topic of referencing and calibration in CSIA is clearly described. This differs from approaches used in quantitative analysis and is often difficult for the newcomer to comprehend. Examples of successful applications of CSIA in food authenticity, forensics, archaeology, doping control, environmental science, and extraterrestrial materials are included. Applications in isotope data treatment and presentation are also discussed and emphasis is placed on the general conclusions that can be drawn from the uses of CSIA. Further instrumental developments in the field are highlighted and selected experiments are introduced that may act as a basis for a short practical course at graduate level.
Download or read book Stable Isotopes in Ecology and Environmental Science written by Robert Michener and published by John Wiley & Sons. This book was released on 2008-04-15 with total page 592 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book highlights new and emerging uses of stable isotope analysis in a variety of ecological disciplines. While the use of natural abundance isotopes in ecological research is now relatively standard, new techniques and ways of interpreting patterns are developing rapidly. The second edition of this book provides a thorough, up-to-date examination of these methods of research. As part of the Ecological Methods and Concepts series which provides the latest information on experimental techniques in ecology, this book looks at a wide range of techniques that use natural abundance isotopes to: follow whole ecosystem element cycling understand processes of soil organic matter formation follow the movement of water in whole watersheds understand the effects of pollution in both terrestrial and aquatic environments study extreme systems such as hydrothermal vents follow migrating organisms In each case, the book explains the background to the methodology, looks at the underlying principles and assumptions, and outlines the potential limitations and pitfalls. Stable Isotopes in Ecology and Environmental Science is an ideal resource for both ecologists who are new to isotopic analysis, and more experienced isotope ecologists interested in innovative techniques and pioneering new uses.
Download or read book Tracking Animal Migration with Stable Isotopes written by and published by Academic Press. This book was released on 2008-04-09 with total page 157 pages. Available in PDF, EPUB and Kindle. Book excerpt: Tracking Animal Migration with Stable Isotopes provides a consolidated overview of the current knowledge of stable isotopes in terrestrial migration research questions. It offers ecologists and conservation biologists provide a practical handbook for those considering using stable isotopes in their migration research. - Presents information for readers to understand how to apply isotopic methods for tracking - Critical information on areas for future research - Practical guidelines and discussions of sample collection, sample preparation, and data analysis - Enhanced understanding of data and statistical analysis in isotope-based studies of migratory animals
Download or read book Principles of Perinatal Neonatal Metabolism written by Richard M. Cowett and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 792 pages. Available in PDF, EPUB and Kindle. Book excerpt: Over the last quarter century or so, specialization within obstetrics and gynecology, and pediatrics has resulted in the development of the disciplines of maternal-fetal medicine and neonatology, respectively. A primary focus of maternal-fetal medicine has been to understand the mechanism(s) of premature delivery and develop treatment modalities for improving the length of gestation. A primary focus of neonatology has been to under stand the causes of respiratory distress in the neonate. Success has resulted, not only in the lengthening of gestation, but an improved understanding of the causes and treatment of neonatal respiratory disease. With increasing success has come the necessity to under stand the metabolic principles of the parturient, the fetal/placenta unit, and the neonate. These principles are clearly very important from multiple aspects. Increased understand ing of metabolism of the pregnant woman would explain the aberrations occurring in normal and abnormal pregnancy and improve nutritional support for the parturient. A prime example of altered metabolism is the parturient with diabetes. Understanding metabolism ofthe fetal/placenta unit is necessary to increase the probability that the fetus will be born appropriate for size irrespective of the gestational age. The various compo nents of neonatal metabolism are important, not only for understanding the changes in physiology and biochemistry occurring in the developing neonate, but the principles by which nutritional support should be provided.
Download or read book Isotope Dilution Mass Spectrometry written by J. Ignacio Garcia Alonso and published by Royal Society of Chemistry. This book was released on 2013 with total page 473 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is the first textbook to present a comprehensive and instructive view of the theory and applications of this growing technique.
Download or read book Stable Isotopes as Indicators of Ecological Change written by and published by Academic Press. This book was released on 2011-09-21 with total page 436 pages. Available in PDF, EPUB and Kindle. Book excerpt: The 20th century has experienced environmental changes that appear to be unprecedented in their rate and magnitude during the Earth's history. For the first time, Stable Isotopes as Indicators of Ecological Change brings together a wide range of perspectives and data that speak directly to the issues of ecological change using stable isotope tracers. The information presented originates from a range of biological and geochemical sources and from research fields within biological, climatological and physical disciplines covering time-scales from days to centuries. Unlike any other reference, editors discuss where isotope data can detect, record, trace and help to interpret environmental change. - Provides researchers with groundbreaking data on how to predict the terrestrial ecosystems response to the ongoing rapid alterations - Reveals how ecosystems have responded to environmental and biotic fluctuations in the past - Includes examples from research by a wide range of biological and physical scientists who are using isotopic records to both detect and interpret environmental change
Download or read book Nitrogen Isotope Techniques written by and published by Elsevier. This book was released on 2012-12-02 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is the first laboratory manual to bring together basic procedures for measurement of stable and radioactive isotopes of nitrogen, with specific applications to plant, soil, and aquatic biology. This bench-top reference gives practical coverage of mass and emission spectrometry, nitrogen fixation, nitrification, and identification, organic nitrogen, and the radioactive isotope 13N. Methods are described so that researchers can adapt them, without the aid of outside references, to virtually any task they may encounter in investigations of nitrogen transformation processes. - Serves as a practical guide for nitrogen isotope techniques - Features studies of nitrogen transformations in terrestrial and aquatic systems - Includes basic measurement techniques plus specific applications for stable and radioactive nitrogen isotopes - Presents detailed protocols, overviews, and key references - Includes fifty figures and sixteen tables - Hands-on reference for both students and researchers
Download or read book Innovative Methods for Ammonium and Amino Acid Natural Nitrogen Isotope Ratio Determination written by Lin Zhang and published by . This book was released on 2007 with total page 150 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Biogeochemical Approaches to Paleodietary Analysis written by Stanley H. Ambrose and published by Springer Science & Business Media. This book was released on 2006-04-18 with total page 284 pages. Available in PDF, EPUB and Kindle. Book excerpt: The study of human diet brings together reseachers from diverse backgrounds ranging from modern human nutrition and biochemistry to the geochemistry of fossilized bones and teeth. The contributions to this volume grow out of the Fourth Advanced Seminar on Paleodiet and provide a forum for scholars with common interests to discuss the latest advances and interpretations and chart future directions for paleodietry research.
Download or read book Tracers in Metabolic Research written by Robert R. Wolfe and published by . This book was released on 1984 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt: Methods for studying metabolism. Determination of substrate kinetics. Constant isotope infusion technique. Determination of substrate kinetics. Bolus-injection technique. Determination of substrate oxidation. Bicarbonate kinetics and natural enrichment. Priming the pool. Nonsteady state kinetics. Selection of sites for infusing isotope andj drawing samples. Specific application. Glucose metabolism. Specific application. Urea. Specific application. Fat meltabolism. Amino acids. Whole-body protein turnover. Total body water. Clinical application of stable isotopes. Analytical methods. Instrumentation. Mass spectrometry. Selected ion monitoring. Preparation of samples. Chromatography. Determination of specific radioactivity. Collection of CO2. Isotope ratio mass spectrometry techniques. Gas chromatography-mass spectrometry methods. In vivo approaches. Isotopic tracers. Advantages of stable isotopes. Biological effects. Enzymatic effects. Definition of terms. Influence of uptake on calculation of rate of appearance. Influence of pool size and complexity. Net movement of tracer and tracee. Clearance. Stable versus radioisotopes. Single-pool analysis. Bicarbonate recovery. Natural abundance of 13C. Practical consideration of performing recovery studies. Determining NaH13 CO3 infusion rate. Determining VCO2. Theory of priming dose. Priming secondary pools. Steele equation. In vivo assessment of steele equation. Glucose. Effective volume of distribution. Urea. Arterial versus central venous infusion.
Download or read book Earth Life and Isotopes written by Ohkouchi Naohiko and published by Trans Pacific Press. This book was released on 2010-08 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Section 3. Method development: 21. Ultra-sensitive elemental analyzer/isotope ratio mass spectrometer for stable nitrogen and carbon isotope analyses / Ogawa, N.O. ... [et al.] -- 22. An improved method for precise determination of carbon isotopic composition of amino acids / Chikaraishi, Y. and Ohkouchi, N. -- 23. Instrumental optimization of compound-specific nitrogen isotope analysis of amino acids by gas chromatography/combustion/isotope ratio mass spectrometry / Chikaraishi, Y. ... [et al.] -- 24. Enantiomer-specific isotope analysis of D-and L-alanine / Takano, Y., Chikaraishi, Y. and Ohkouchi, N. -- Appendix. Summary of methods for measuring isotopic compositions presented in this book / Ohkouchi, N., Tayasu, I., and Koba, K.
Download or read book Stable Isotopes in Human Nutrition written by S. A. Abrams and published by CABI. This book was released on 2003-04-25 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt: The use of stable isotopes in nutritional studies is now widespread, and the technique is becoming increasingly popular. Practical applications are numerous and include:calcium and iron absorption studiesstudies looking at the impacts of diet, physical activity, aging, and medical therapy and supplementation on nutrient metabolismthe measurement of energy cost of pregnancystudies on the causes of growth faltering in infantsinvestigations into childhood and adult obesity.This book is designed as a laboratory handbook of methods used to perform stable isotope studies in humans. It covers basic principles, dosage information, sample preparation procedures, analytical instrumentation, and necessary mathematical methods and provides the fundamentals to enable researchers to evaluate and establish stable isotope methods in their own laboratories.
Download or read book Nitrogen Isotope Analysis of Ammonium and Glycine written by and published by . This book was released on with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Stable isotope techniques can be used as a tool in nitrogen cycling studies of different ecosystems. The studies are based on measurement of the heavy (15N)- to- light (14N) isotopic ratios of nitrogen in different biospheric pools. Isotope ratio mass spectrometry (IRMS) is the most precise technique to use for analysis of nitrogen isotopic ratios. This thesis deals with the development of methods for compound-specific nitrogen isotope analysis of ammonium and glycine in aqueous solutions and soil extracts using Gas Chromatography - Combustion (GC-C) - IRMS. For ammonium, three different techniques were developed: equilibrium headspace analysis, solid phase microextraction (SPME) and the purge and trap (P & T) technique, which were all based on conversion of ammonium to ammonia with subsequent separation of ammonia for analysis. In the SPME and P & T approaches, custom-made absorbents were used for pre-concentration, followed by thermal desorption into the GC-C-IRMS system. For the equilibrium headspace technique, high precision measurements of the nitrogen isotopic ratio were obtained for concentrations above 420 mg N L-1. With further improvements and the use of suitable equipment, the method has the potential to be used for solutions containing ammonium in the low mg N L-1 range. The SPME technique increased the sensitivity by a factor of » 3 compared to the headspace technique, but was less precise. In addition, the NafionÒ material used for absorption showed a memory effect in the desorption step. With the P & T technique a large variation in the measured isotopic value was observed (using solutions containing 2 mg N L-1) which was due to a non-quantitative thermal desorption. However, with further improvements, the P & T technique has the potential to be used for samples containing below 1.0 µg N, which is a much lower amount than that possible with any method used today. A method for determination of the nitrogen isotopic ratio in free glycine in soil extract
Download or read book Strategies for High precision Nitrogen and Carbon Position specific Isotope Analysis written by Nabil Mohamed Reda Saad and published by . This book was released on 2003 with total page 316 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Plant Physiological Ecology written by R. Pearcey and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 463 pages. Available in PDF, EPUB and Kindle. Book excerpt: Physiological plant ecology is primarily concerned with the function and performance of plants in their environment. Within this broad focus, attempts are made on one hand to understand the underlying physiological, biochemical and molecular attributes of plants with respect to performance under the constraints imposed by the environment. On the other hand physiological ecology is also concerned with a more synthetic view which attempts to under stand the distribution and success of plants measured in terms of the factors that promote long-term survival and reproduction in the environment. These concerns are not mutually exclusive but rather represent a continuum of research approaches. Osmond et al. (1980) have elegantly pointed this out in a space-time scale showing that the concerns of physiological ecology range from biochemical and organelle-scale events with time constants of a second or minutes to succession and evolutionary-scale events involving communities and ecosystems and thousands, if not millions, of years. The focus of physiological ecology is typically at the single leaf or root system level extending up to the whole plant. The time scale is on the order of minutes to a year. The activities of individual physiological ecologists extend in one direction or the other, but few if any are directly concerned with the whole space-time scale. In their work, however, they must be cognizant both of the underlying mechanisms as well as the consequences to ecological and evolutionary processes.
Download or read book Topics in Oceanography written by Enrico Zambianchi and published by BoD – Books on Demand. This book was released on 2013-07-10 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt: Oceanography is the par excellence interdisciplinary science thanks to its peculiar setting within a fluid environment that makes connections extremely efficient. The oceans connections are well mirrored in the chapters of this book that share a quite explicit multidisciplinary and multi-environmental character. The book provides chapters on very different topics under very different settings, some with a focused angle, others with a broader approach, yet all sharing the idea that we need to understand the small pieces in order to put together the big picture for a much larger mechanism, the functioning of the ocean as a whole.
