Trace element analysis by Mass Spectrometry

An overview of the mass spectrometry and chromatographic systems we use and the trace element analyses we perform is given in the figure below. The instruments are either in our lab at ETHZ or accessible at the Eawag Mass Spec Facility (website for this facility is planned).

Enlarged view: MS-Lab Overview

1. Thermal desorption-GC-ICP-MS (at ETHZ), for the sensitive quantification of volatile TE species in air and water samples (pg m-3 or pg L-1 levels).

2. ICP-MS & ICP-MS/MS (at ETHZ & Eawag Mass Spec Facility), for the fast and sensitive quantification of major and trace elements. The two ICP-MS/MS are mostly used for elements subjected to a variety of spectral interferences (e.g, Se, S, P).

3. LC-ICP-MS/MS (at ETHZ & Eawag Mass Spec Facility), for a sensitive quantification of known TE species in water samples and extracts of solid samples (ng L-1 or µg kg-1 levels). This includes the quantification of (oxy)anions (e.g., AsO3-, AsO42-, SeO32-, SeO42- , I-, IO3-), small organic molecules (e.g., methylated As species, Se metabolites) as well as TE bound to organic matter and nanoparticles or colloids. One LC system is equipped with an UV detector to detect organic matter simultaneously to TE.

4. LC-Orbitrap-MS (at ETHZ), for the identification of organic TE species that cannot be identified and quantified using LC-ICP-MS/MS analyses, e.g., due to the absence of standards. Examples are organic Se or S metabolites or TEs that are bound to natural organic matter. The LC system also includes a Charged Aerosol Detector (CAD) that runs in parallel to the Orbitrap-MS and allows an unspecific detection, but more robust semi-quantification of organic molecules complementing the Orbitrap characterization of molecules.