We produced continuous records of sea surface salinity and isotopic composition from 1998 to 2004 at Ishigaki Island, southwest Japan, and found clear seasonal variations in salinity and oxygen isotopic composition and increasing trends of them after 1999. These increasing trends could be principally due to the decreasing difference between local precipitation (P) and evaporation (E), as a result of the reduction of horizontal vapour transport from adjacent oceans. When samples collected in heavy rainfall events were excluded, the average Deltadelta(18)O/Delta salinity slope was obtained as 0.31, 0.35 in summer and 0.28 in winter. Estimated E/P ratios based on the isotopic box model are in good agreement with the ratios of independently estimated E to observed P.
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http://dx.doi.org/10.1080/10256010903083847 | DOI Listing |
Mar Pollut Bull
January 2025
State Key Laboratory of Marine Geology, Tongji University, Shanghai 200092, China.
Investigations of the spatial-temporal variations of nutrients within mangrove coastal zones are essential for assessing the environmental status of an aquatic ecosystems. However, major processes controlling nitrate cycle along the submarine groundwater discharge (SGD) pathway from the mangrove areas to adjacent tidal creek remain underexplored. A time series measurement over a 25 h tidal cycle was conducted in Qinglan Bay tidal creek (Hainan Island, China).
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.
Nat Commun
January 2025
Atomic and Mass Spectrometry-A&MS research unit, Department of Chemistry, Ghent University, Ghent, Belgium.
The Chicxulub asteroid impact event at the Cretaceous-Paleogene (K-Pg) boundary ~66 Myr ago is widely considered responsible for the mass extinction event leading to the demise of the non-avian dinosaurs. Short-term cooling due to massive release of climate-active agents is hypothesized to have been crucial, with S-bearing gases originating from the target rock vaporization considered an important driving force. Yet, the magnitude of the S release remains poorly constrained.
View Article and Find Full Text PDFSci Total Environ
January 2025
China National Environmental Monitoring Centre, Beijing 100012, China.
The riverine dissolved organic matter (DOM) pool constitutes the largest and most dynamic organic carbon reservoir within inland aquatic systems. Human activities significantly alter the distribution of organic matter (OM) in rivers, thereby affecting the availability of DOM. However, the impact of total suspended solids (TSS) on DOM under anthropogenic influence remains insufficiently elucidated.
View Article and Find Full Text PDFFood Chem
December 2024
Atomic and Mass Spectrometry - A&MS Research Unit, Department of Chemistry, Ghent University, 9000 Ghent, Belgium. Electronic address:
The disruption of Cu homeostasis is associated with the pathogenesis of many diseases and can result in alterations in Cu isotope fractionation. Changes in the Cu isotope ratio (Cu/Cu) of body fluids and tissues have been observed in liver disorders, cancers, and other diseases, displaying diagnostic/prognostic potential. However, it is not entirely clear whether certain physiological or lifestyle factors may also influence the bodily Cu isotopic composition, potentially obfuscating the signature of the pathology.
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