Stable-hydrogen isotope heterogeneity in keratinous materials: mass spectrometry and migratory wildlife tissue subsampling strategies

2006 ◽  
Vol 20 (16) ◽  
pp. 2505-2510 ◽  
Author(s):  
Leonard I. Wassenaar ◽  
Keith A. Hobson
Keyword(s):  
Mass Spectrometry ◽  
Hydrogen Isotope ◽  
Stable Hydrogen Isotope ◽  
Keratinous Materials ◽  
Migratory Wildlife

scholarly journals Mass spectrometric measurement of hydrogen isotope fractionation for the reactions of chloromethane with OH and Cl

2018 ◽  
Author(s):  
Frank Keppler ◽  
Enno Bahlmann ◽  
Markus Greule ◽  
Heinz Friedrich Schöler ◽  
Julian Wittmer ◽  
...  
Keyword(s):  
Hydrogen Isotope ◽  
Isotope Fractionation ◽  
Isotope Effects ◽  
Isotope Analysis ◽  
Isotope Ratio Mass Spectrometry ◽  
Detailed Knowledge ◽  
Mass Spectrometric Measurement ◽  
Isotopic Analyses ◽  
Chlorine Radicals ◽  
Stable Hydrogen Isotope

Abstract. Chloromethane (CH3Cl) is an important provider of chlorine to the stratosphere but yet lacks detailed knowledge of its budget. Stable isotope analysis is potentially a powerful tool to constrain CH3Cl flux estimates. The largest degree of isotope fractionation is expected to occur for deuterium in CH3Cl in the hydrogen abstraction reactions with its main sink reactant tropospheric OH and its minor sink reactant Cl atoms. We determined the isotope fractionation by stable hydrogen isotope analysis of the fraction of CH3Cl remaining after reaction with hydroxyl and chlorine radicals in a 3.5 m3 Teflon smog-chamber at 293 ± 1 K. We measured the increasing stable hydrogen isotope values of the unreacted CH3Cl using compound specific thermal conversion isotope ratio mass spectrometry. The isotope fractionations of CH3Cl for the reactions with hydroxyl and chlorine radicals were found to be −242 ± 7 mUr (or ‰) and −280 ± 11 mUr, respectively. For comparison, we performed similar experiments using methane (CH4) as the target compound with OH and obtained a fractionation constant of −205 ± 6 mUr which is in good agreement with values previously reported. The observed large kinetic isotope effects are helpful when employing isotopic analyses of CH3Cl in the atmosphere to improve our knowledge of its atmospheric budget.

scholarly journals Solid state catalytic hydrogen exchange for deuterium in cycloprolylglycine

2019 ◽  
Vol 484 (3) ◽  
pp. 307-311
Author(s):  
A. K. Dadayan ◽  
Yu. A. Borisov ◽  
E. V. Bocharov ◽  
Yu. A. Zolotarev ◽  
I. Yu. Nagaev ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Solid State ◽  
Hydrogen Isotope ◽  
Isotope Exchange ◽  
Density Functional ◽  
Hydrogen Exchange ◽  
Functional Theory ◽  
Catalytic Hydrogen ◽  
Spillover Hydrogen ◽  
High Stereoselectivity

The reaction of spillover hydrogen (SH) with cyclopropylglycine (cPG) in high-temperature solid-state catalytic hydrogen isotope exchange (HTCIE) has been studied experimentally and using density functional theory (DFT). NMR spectroscopy and mass spectrometry have shown a high regioselectivity and stereoselectivity for the reaction of spillover hydrogen with cPG fragments. The Gly fragment has been shown to be the most reactive in HTCIE, for which high stereoselectivity of substitution of hydrogen by deuterium has been demonstrated.

scholarly journals Round-trip across the Sahara: Afrotropical Painted Lady butterflies recolonize the Mediterranean in early spring

2018 ◽  
Vol 14 (6) ◽  
pp. 20180274 ◽  
Author(s):  
Gerard Talavera ◽  
Clément Bataille ◽  
Dubi Benyamini ◽  
Martin Gascoigne-Pees ◽  
Roger Vila
Keyword(s):  
Hydrogen Isotope ◽  
Migratory Birds ◽  
Early Spring ◽  
Round Trip ◽  
Reverse Migration ◽  
Vanessa Cardui ◽  
Tangible Evidence ◽  
Stable Hydrogen Isotope ◽  
Sub Saharan ◽  
Work Supports

The Palearctic–African migratory circuit has been typically associated with birds. Very few insects are known to endure annual trans-Saharan circuits, but the Painted Lady butterfly ( Vanessa cardui ) is an exception. While it was demonstrated that this species massively migrates from Europe to the Afrotropics during the autumn, the existence of a reverse migration from the Afrotropics to Europe in the early spring remains hypothetical. Here, we analysed wing stable hydrogen isotope values (δ 2 H) of V. cardui migrants collected from February to April across the circum-Mediterranean region. We assessed their region of natal origin by comparing their wing isotope signature predicted δ 2 H values (isoscape). The results unambiguously demonstrate a sub-Saharan origin for many individuals, especially those collected in February, representing the first tangible evidence for a reverse northwards trans-Saharan migration in spring. This work supports the view that the Afrotropics (mostly exploited from September to February) is key in the V. cardui Palearctic–African population dynamics. This species relies on both temperate and tropical habitats to complete their multigenerational cycle, an unprecedented adaptation for butterflies and for most migratory insects. Such a migratory circuit has strong parallelisms with those of migratory birds.

scholarly journals Stable Isotope Evidence Links Breeding Geography and Migration Timing in Wood Warblers (Parulidae)

The Auk ◽  
2006 ◽  
Vol 123 (2) ◽  
pp. 431-437 ◽  
Author(s):  
Jeffrey F. Kelly
Keyword(s):  
Hydrogen Isotope ◽  
Life Histories ◽  
Isotope Ratios ◽  
Interspecific Variation ◽  
Autumn Migration ◽  
Breeding Sites ◽  
Migration Timing ◽  
Wood Warblers ◽  
Stable Hydrogen Isotope ◽  
Hydrogen Isotope Ratios

AbstractTracking seasonal movements of songbirds is a key step in understanding the annual cycle of migrants. To better understand autumn migration of wood warblers, I analyzed stable-hydrogen isotope ratios of feathers collected from three species captured during stopover at the Bosque del Apache National Wildlife Refuge, New Mexico. To assess the form and strength of the relationship between timing of migration and breeding origins, I regressed stable-hydrogen isotope ratios of feathers against date of capture. These analyses indicated that Orange-crowned Warblers (Vermivora celata) and Common Yellowthroats (Geothlypis trichas) breeding in the southern portion of these species' ranges precede their northern conspecifics in autumn migration. By contrast, Yellow Warblers (Dendroica petechia) from northern breeding sites arrived before more southerly breeding conspecifics. This pattern is similar to that reported previously in Wilson's Warbler (Wilsonia pusilla). These findings suggest that, among wood warblers, (1) timing of autumn migration is often strongly related to breeding location and (2) interspecific variation in the direction of this relationship is large. The direction and strength of these patterns have implications for our understanding of inter- and intraspecific geographic variation in the life histories of migrants.Evidencia de Isótopos Estables Conecta la Geografía de Nidificación con el Momento de la Migración en Especies de Parulidae

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