We have studied the highly selective homogeneous iridium-catalyzed hydrogen isotope exchange (HIE) with deuterium or tritium gas as an isotope source in water and buffers. With an improved water-soluble Kerr-type catalyst, we have achieved the first insight into applying HIE reactions in aqueous media with varying pH. Density functional theory (DFT) calculations gave consistent insights in the calculated energies of transition states and coordination complexes, further explaining the observed reactivity and guidance on the scope and limitations for HIE reactions in water. Finally, we successfully adapted these findings to tritium chemistry.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1002/anie.202301512 | DOI Listing |
Sci Total Environ
January 2025
University of Tokyo, Japan.
Over the last 20 years, we have dramatically improved hydrometeorological data including isotopes, but are we making the most of this data? Stable isotopes of oxygen and hydrogen in the water molecule (stable water isotopes - SWI) are well known tracers of the global hydrological cycle producing critical climate science. Despite this, stable water isotopes are not explicitly included in influential climate reports (e.g.
View Article and Find Full Text PDFJ Proteome Res
January 2025
Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States.
Proteo-SAFARI is a shiny application for fragment assignment by relative isotopes, an R-based software application designed for identification of protein fragment ions directly in the / domain. This program provides an open-source, user-friendly application for identification of fragment ions from a candidate protein sequence with support for custom covalent modifications and various visualizations of identified fragments. Additionally, Proteo-SAFARI includes a nonnegative least-squares fitting approach to determine the contributions of various hydrogen shifted fragment ions ( + 1, + 1, - 1, - 2) observed in UVPD mass spectra which exhibit overlapping isotopic distributions.
View Article and Find Full Text PDFAppl Spectrosc
January 2025
Department of Earth Sciences, Geological Institute, , ETH Zurich, Zurich, Switzerland.
Cavity ring-down spectroscopy (CRDS) is rapidly becoming an invaluable tool to measure hydrogen (δ²H) and oxygen (δO) isotopic compositions in water, yet the long-term accuracy and precision of this technique remain relatively underreported. Here, we critically evaluate one-year performance of CRDS δ²H and δO measurements at ETH Zurich, focusing on high throughput (~200 samples per week) while maintaining required precision and accuracy for diverse scientific investigations. We detail a comprehensive methodological and calibration strategy to optimize CRDS reliability for continuous, high-throughput analysis using Picarro's "Express" mode, an area not extensively explored previously.
View Article and Find Full Text PDFFood Chem
December 2024
Food Quality and Design, Wageningen University & Research, P.O. Box 17, 6700, AA, Wageningen, The Netherlands; School of Agriculture and Food Science, University College Dublin, Dublin 4, Ireland. Electronic address:
This study aims to assess the effects of oven heating on the isotopic ratios of eight formulated wheat-processed products with different gluten-to-starch ratios. Two heating treatments were applied: limited heating in an oven with exposure to 100 °C for a specific time (cooking time-dependent) and extended heating in an oven with exposure to 100 °C, 180 °C and 260 °C for 6 min. Results showed limited heating exposure did not alter the δH and δO in the wheat-processed products.
View Article and Find Full Text PDFSci Data
December 2024
Centre for Climate Change Research, Indian Institute of Tropical Meteorology, Ministry of Earth Sciences, Pune, India.
High-frequency precipitation (solid/liquid) isotope datasets are useful for identification of moisture sources and various dynamical and thermodynamical processes controlling precipitation formation. Here, we report three-year (2019-2021) daily rain isotope (both oxygen, δO hereafter, and hydrogen, δH, hereafter) datasets from three unique locations in India during the Indian Summer Monsoon (ISM). The locations are- (1) Port Blair- an island situated in the Bay of Bengal (BoB); (2) Mahabaleshwar, located at the crest of the Western Ghats Mountain; and (3) Tezpur, in northeast India, situated close to a dense forest.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!