Vortrag Michael Steppert

Date

Sep 28, 2017

Time

10:00 AM - 11:30 AM

Speaker

Michael Steppert

Language

en

Main Topic

Chemie

Other Topics

Physik

Host

Moritz Schmidt

Description

Update on the ESI-Orbitrap mass spectrometer: redesign of the ion source region and its implications for measurements in aquatic systems and first MS/MS-data on molybdenum species in strongly acidic media Dr. Michael Steppert Institut für Radioökologie und Strahlenschutz, Leibniz Universität Hannover The ESI-Orbitrap Elite hybrid mass spectrometer (IRS Hanover) can transfer ions from solutions to the gas phase and analyze their mass-to-charge ratios. Compared to the ESI-ToF-MS applied by our group before, the new device has advantages in terms of sensitivity and mass resolution. However it also has a drawback of generating measurement artifacts, due to the more invasive transfer from atmospheric pressure to the vacuum. These artifacts are forming due to collision-induced dissociation reactions of the ions of interest, as the whole solvent shell of the ions is removed in the transfer region. In order to suppress these artifacts, the source region of the device was redesigned to generate softer sampling conditions. Advantages, drawbacks and their implications on speciation measurements by the ESI-Orbitrap will be discussed. The second part of the talk is dedicated to MS/MS-investigations on molybdenum in strongly acidic media. Being a possible candidate as an inert fuel matrix for new proposed reactor types, understanding the molybdenum chemistry in strongly acidic media is important for the reprocessing steps. We reported the results on the stoichiometry and relative abundances of the molybdenum solution species at the IRE seminar before. However, the structures of these species remained unclear. To shed light on the structural properties of these species we applied MS/MS-techniques. We will propose possible structures that might be a good starting point for quantum chemical calculations on the cationic molybdenum species present in solution.

Last modified: Sep 28, 2017, 9:41:24 AM