PP032-0005
Elemental composition and number concentration of individual nano- and micro- dust particles measured by single particle-ICPMS in East Antarctic ice during the last climatic cycle

Friday, 11 December 2020
Poster
Madeleine Claire Lomax-Vogt1, John Olesik2, Aja Ellis3, Cole Bradley4, Luke Monroe5, Garret Bland6, Ryan C Sullivan7 and Paolo Gabrielli3, (1)The Ohio State University, Department of Chemistry and Biochemistry, Columbus, OH, United States, (2)The Ohio State University, School of Earth Sciences, Columbus, OH, United States, (3)The Ohio State University, Byrd Polar and Climate Research Center, Columbus, OH, United States, (4)The Ohio State University, School of Earth Sciences, Columbus, United States, (5)Carnagie Mellon University, Department of Chemistry, Pittsburgh, United States, (6)Carnagie Mellon University, Civil and Environmental Engineering, Pittsburgh, United States, (7)Carnegie Mellon University, Center for Atmospheric Particle Studies, Pittsburgh, PA, United States
Abstract:
The number concentration and elemental chemical composition of individual atmospheric nano-and micro- dust particles affect climactic processes, directly by reflecting, scattering, or absorbing solar radiation; and indirectly by acting as ice and cloud condensation nuclei. Previously, the number concentration and size distribution of aeolian dust particles entrapped in glacial ice has been typically determined by Coulter counter, but only for particles larger than about 0.5 µm. In addition, only the bulk elemental composition of glacier particles was determined by dissolving the particles and measuring the average signal of each element by inductively coupled plasma mass spectrometry. Single particle inductively coupled plasma mass spectrometry (spICP-MS) has been used to measure the number concentration and size of suspended engineered particles, such as Ag nanoparticles (1,2). We used spICP-MS to measure the elemental composition and mass of the single nano- and micro- dust particles entrapped in horizontal ice sections from Taylor Glacier (East Antarctica) spanning part of the last climatic cycle (9-44 kyr BP). Two different instruments were used: spICP-Quadrupole MS which measures one isotope at a time and spICP-Time of Flight MS which acquires a complete elemental mass spectrum for every particle. Our goal is to determine if and how the number concentration and elemental composition of individual particles has changed over time. Preliminary results of the first sections indicate that the ice contained a larger amount of nanoparticles during the dustier Glacial period than the Holocene. Individual nanoparticles contained 1 to 15 different detectable elements (including Si, Al, Ti, Fe) in amounts from less than 1 fg to several hundreds of fg. Fifty different elements were detected among the Antarctic particles. Ultimately, these measurements will allow the atmospheric concentration and mineralogy of aeolian dust to be more comprehensively estimated. This in turn will allow climate model accuracy to be improved by incorporating particle chemical and physical properties into simulations.

  1. Degueldre, Colloids Surf. A Physicochem. Eng. Asp., 217, 137-142 (2003)
  2. M. Montaño, Anal. Bioanal. Chem., 408, 5053-5074 (2016)
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