We submitted individual aliphatic and polycyclic aromatic hydrocarbons in samples of hydrothermal petroleum from Escanaba Trough to compound specific isotope analysis to trace their origins. The carbon isotope compositions of the alkanes and polycyclic aromatic hydrocarbons (means -27.5 and -24.7%, respectively) reflect a primarily terrestrial organic matter source.
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http://dx.doi.org/10.1016/s0146-6380(97)00042-9 | DOI Listing |
Sci Total Environ
January 2025
National Laboratory for Agriculture and the Environment, Ames, IA 50011, USA.
Identifying the origins of storm fluvial particulate organic carbon (POC) provides information about the hydrological connectivity within the river corridor and the roles of the land-stream interface in the carbon cycle. However, current understanding of storm-induced POC source dynamics is constrained by observations limited in space and time. This study presents a unique approach integrating higher spatial and temporal resolution sampling with a multi-biomarker analysis to better understand POC source dynamics across scales.
View Article and Find Full Text PDFPLoS One
January 2025
Department of Archaeology, Simon Fraser University, Burnaby, B.C., Canada.
Franchthi Cave, in the Greek Peloponnese, is a well-known Paleolithic, Mesolithic and Neolithic site, with several human burials. In many parts of Europe there is clear evidence from archaeological and isotopic studies for a diet change between the Mesolithic and Neolithic periods. This is especially the case in coastal contexts where there is often a shift from predominantly marine food diets in the Mesolithic to terrestrial (presumably domesticated) foods in the Neolithic.
View Article and Find Full Text PDFNat Geosci
January 2025
Department of Earth Sciences 'Ardito Desio', Università degli Studi di Milano, Milan, Italy.
Atmospheric CO is thought to play a fundamental role in Earth's climate regulation. Yet, for much of Earth's geological past, atmospheric CO has been poorly constrained, hindering our understanding of transitions between cool and warm climates. Beginning ~370 million years ago in the Late Devonian and ending ~260 million years ago in the Permian, the Late Palaeozoic Ice Age was the last major glaciation preceding the current Late Cenozoic Ice Age and possibly the most intense glaciation witnessed by complex lifeforms.
View Article and Find Full Text PDFRapid Commun Mass Spectrom
April 2025
Solar System Exploration Division, NASA Goddard Space Center, Greenbelt, Maryland, USA.
Rationale: Extraterrestrial amines and ammonia are critical ingredients for the formation of astrobiologically important compounds such as amino acids and nucleobases. However, conventional methods for analyzing the composition and isotopic ratios of volatile amines suffer from lengthy derivatization and purification procedures, high sample mass consumption, and chromatographic interferences from derivatization reagents and non-target compounds.
Methods: Here we demonstrate a highly efficient method to analyze the composition and compound specific isotopic ratios of C to C amines as well as ammonia based on solid phase micro-extraction (SPME) on-fiber derivatization.
Environ Toxicol Chem
January 2025
Molecular Biosciences PhD Program, Middle Tennessee State University, Murfreesboro, TN, United States.
Riparian spiders are used in ecotoxicology as sentinels of bioavailable contaminants that are transferred from aquatic to terrestrial habitats via emergent aquatic insects. Spiders in the family Tetragnathidae are particularly of interest because a high proportion of their diet consists of emergent aquatic insects and their contaminant loads reflect the amount transferred through the food web to riparian predators. The transfer of contaminants can be determined through food web tracers such as stable isotopes and polyunsaturated fatty acids; however, it is unclear how contaminants and tracers vary over the course of a year.
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