نتایج جستجو برای: gc irms

تعداد نتایج: 36392  

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2009
Richard N Zare Douglas S Kuramoto Christa Haase Sze M Tan Eric R Crosson Nabil M R Saad

A continuous-flow cavity ring-down spectroscopy (CRDS) system integrating a chromatographic separation technique, a catalytic combustor, and an isotopic (13)C/(12)C optical analyzer is described for the isotopic analysis of a mixture of organic compounds. A demonstration of its potential is made for the geochemically important class of short-chain hydrocarbons. The system proved to be linear ov...

Journal: :Soft Computing 2022

In industrial applications and automation, the robotic manipulators exhibit a significant role. Several complex systems performed number of works named spray painting, welding, assembly, pick place action, etc. The end-effector’s position joint angles play vital role since any task is activated inside pre-defined manipulator’s work space. Also, problem trajectory planning very challenging in fi...

2000
Oliver Kracht Gerd Gleixner

Elemental analyses (H, N, C, O, S), bulk isotope analyses (C, N) and C content of pyrolysis products from Sphagnum moss, underlying peat from a bog and the bog water (Hohlohsee, Black Forest, Germany) were performed to identify humi®cation processes in the early diagenesis of peat formation and to determine the origin of dissolved organic matter (DOM) in the bog lake. Atomic ratios of bulk elem...

2008
J. Mohn M. J. Zeeman

Continuous analysis of the 13C/12C ratio of atmospheric CO2 (δC-CO2) is a powerful tool to quantify CO2 flux strengths of the two major ecosystem processes assimilation and respiration. Traditional laboratory techniques such as isotope ratio mass spectrometry (IRMS) in combination with flask sampling are subject to technical limitations that do not allow to fully characterize variations of atmo...

Journal: :Journal of chromatography. A 2015
J A González-Pérez N T Jiménez-Morillo J M de la Rosa G Almendros F J González-Vila

Polyethylene is probably the most used plastic material in daily life and its accurate analysis is of importance. In this communication the chemical structure of polyethylenes is studied in detail using conventional analytical pyrolysis (Py-GC/MS), bulk stable isotopic analysis (IRMS) and pyrolysis compound specific stable isotopic analysis (Py-CSIA) to measure stable isotope proportions (δ(13)...

2017
Linda van Roij Appy Sluijs Jelmer J. Laks Gert‐Jan Reichart

RATIONALE Analyses of stable carbon isotope ratios (δ13 C values) of organic and inorganic matter remains have been instrumental for much of our understanding of present and past environmental and biological processes. Until recently, the analytical window of such analyses has been limited to samples containing at least several μg of carbon. METHODS Here we present a setup combining laser abl...

Journal: :Ecology 2009
Thomas Larsen D Lee Taylor Mary Beth Leigh Diane M O'Brien

Amino acids play an important role in ecology as essential nutrients for animals and as currencies in symbiotic associations. Here we present a new approach to tracing the origins of amino acids by identifying unique patterns of carbon isotope signatures generated by amino acid synthesis in plants, fungi, and bacteria ("13C fingerprints"). We measured amino acid delta 13C from 10 C3 plants, 13 ...

Journal: :Rapid communications in mass spectrometry : RCM 2012
Sandra Reinnicke Dieter Juchelka Sibylle Steinbeiss Armin Meyer Andreas Hilkert Martin Elsner

RATIONALE Compound-specific isotope analysis (CSIA) relies on continuous flow combustion of organic substances to CO(2) and N(2) in a miniature reactor to measure (13)C/(12)C and (15)N/(14) N stable isotope ratios. Accurate analysis is well established for many volatile hydrocarbons. In contrast, compounds which contain hetero and halogen atoms are less volatile and may be more recalcitrant to ...

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