Dissolved organic matter in the deep TALDICE ice core: A nano-UPLC-nano-ESI-HRMS method

Science of the Total Environment
By: , and 

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Abstract

Trace organic compounds in deep ice cores supply important paleoclimatic information. Untargeted analyses of dissolved organic matter provide an overview of molecular species in ice samples however, sample volumes usually required for these analyses are generally not available from deep ice cores. Here, we developed an analytical method using a nano-UPLC-nano-ESI-HRMS to detect major molecular species in ice cores. Samples (4 µL) from the TALos Dome Ice CorE (TALDICE), allowed investigating molecular species across a range of depths including during glacial and interglacial periods. We detected 317 chemical species that were tentatively assigned to fatty acids, hydroxy fatty acids and their degradation products (oxo-fatty acids and dicarboxylic acids), as well as oxidation byproducts of isoprene and monoterpenes. These compounds indicate that the main sources of the organic fraction are microbes as well as primary and secondary aerosols. Interglacial samples encompass a wide range of species including compounds from the oxidation of isoprene and monoterpenes as well as unsaturated fatty acids, while the glacial samples contained less diverse species. This difference may be due to decreased temperatures during the glacial period inhibiting terrestrial vegetation growth and increasing the sea ice extent, thereby weakening the emission sources.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Dissolved organic matter in the deep TALDICE ice core: A nano-UPLC-nano-ESI-HRMS method
Series title Science of the Total Environment
DOI 10.1016/j.scitotenv.2019.134432
Volume 700
Year Published 2019
Language English
Publisher Elsevier
Contributing office(s) Geosciences and Environmental Change Science Center
Description 134432