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Ultra-high resolution mass spectrometer - Orbitrap-MS

English title Ultra-high resolution mass spectrometer - Orbitrap-MS
Applicant El Haddad Imad
Number 198140
Funding scheme R'EQUIP
Research institution Paul Scherrer Institut
Institution of higher education Paul Scherrer Institute - PSI
Main discipline Climatology. Atmospherical Chemistry, Aeronomy
Start/End 01.12.2020 - 30.11.2021
Approved amount 178'500.00
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All Disciplines (2)

Climatology. Atmospherical Chemistry, Aeronomy
Physical Chemistry

Keywords (5)

atmospheric chemistry; climate change; mass spectrometry; public health; molecular analysis

Lay Summary (French)

Les aérosols ont des impacts climatique et sanitaire importants. La capacité de la communauté scientifique à étudier les processus d'émission et de formation des aérosols, leurs propriétés et leurs impacts est régie par les capacités de mesure existantes. En raison du caractère dynamique des aérosols, leurs propriétés doivent être mesurées en ligne. La grande majorité de l'instrumentation en ligne actuelle est basée sur la spectrométrie de masse. Ces instruments sont équipés d'analyseurs de masse à temps de vol, qui ont une résolution en masse limité prévenant l'identification des composés à haut poids moléculaire. L'année dernière, nous avons développé une nouvelle technique en ligne basée sur un spectromètre de masse Orbitrap à ultra haute résolution.
Lay summary
Dans ce projet, nous avons demandé le financement pour un spectromètre de masse Orbitrap. La haut résolution de l'instrument transformera fondamentalement les informations chimiques récupérables par rapport au spectromètre de masse actuellement utilisé, permettant l’identification de composés sans ambiguïté. Le nouvel équipement contribuera à un grand nombre d'initiatives de recherche innovantes couvrant les principaux domaines de la chimie atmosphériques. Celles-ci comprennent (1) l’identification des sources d’aérosols dans l’air ambiant, (2) l'élucidation de la composition des aérosols oxygénés et de leurs précurseurs, (3) la détermination des composants clés pour la santé et le climat, (4) des études cinétiques et mécanistiques, et (5) le soutien infrastructurel à grande échelle.
Direct link to Lay Summary Last update: 05.12.2020

Responsible applicant and co-applicants


Group / person Country
Types of collaboration
CNRS France (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
- Research Infrastructure
- Exchange of personnel

Associated projects

Number Title Start Funding scheme
188662 The interplay between reactive oxygen species and the multiphase chemistry of nitrogen, halogen and secondary organic species in aerosol particles 01.03.2020 Project funding
188624 MOLecular composition of ORGanics in Atmospheric Aging Experiments (MOLORG) 01.03.2020 Project funding
189883 Which aerosol components and processes control the toxicity of ambient particulate pollution? Targeted studies of aerosol oxidative potential 01.04.2020 China 2016


Aerosols are considered the single largest uncertainty in assessing the human contribution to climate change and global warming. Exposure to aerosol pollution is one of the top five health risks worldwide, alongside with diabetes, smoking, high blood pressure and being overweight. These aerosols are sub-micrometer particles suspended in the air, either directly emitted from primary sources, e.g. biomass burning, or formed in the atmosphere through the oxidation of gaseous precursors, e.g. natural emissions from vegetation. The ability of the scientific community to investigate aerosol emission and formation processes, their properties, and their societal impacts is governed by existing measurement capabilities. Due to the large dynamic character of aerosol particle over a large range of time scales, aerosol properties need to be measured online. The vast majority of current state-of-the-art online instrumentation are based on mass spectrometry. While these instruments are equipped with time-of-flight mass analyzers (TOF, resolution between 4’000 and 14’000), taking advantage of their robustness in the field, their low detection limits and their rapid response, the TOF limited mass resolving power prevents the discrimination between isobaric compounds, especially at higher molecular weights and when sampling the immensely complex aerosol matrix. In addition, a general shortcoming of mass spectrometry is the lack of information on molecular structure and functional groups, which can-not be trivially inferred from the ion elemental composition. Last year, we have initiated a collaboration with IRCELYON (France) to explore the much higher resolution of the Orbitrap-MS (resolution: >70’000; available at IRCELYON) for online analysis of particle and gas phase. We have successfully reengineered the Orbitrap-MS nozzle to allow its interface with the inlets that are currently coupled with the TOF, conducted first proof-of-principle experiments and have just published the results in a manuscript led by a PhD student from PSI. Based on this success, we request herein the funding to purchase an Orbitrap-MS. The higher resolution of the Orbitrap-MS will fundamentally alter the retrievable chemical information compared to the currently used TOF-MS, enabling unambiguous compound identifications. This will be essential for (1) identifying high molecular weight compounds, (2) resolving the contribution of species containing multiple heteroatoms (organosulfates and organonitrates), and (3) lowering the significant noise resulting from fitting overlapping peaks. Equally importantly, the Orbitrap-MS provides the possibility to obtain tandem mass spectra (MS2) for selected ions, which is highly valuable for distinguishing isomers and obtaining for the first time structural and functional group information. This will be essential for mechanistic studies and determination of key physicochemical parameters (e.g. volatility). The new equipment will be instrumental in a number of innovative research initiatives covering all areas of atmospheric aerosol chemistry. These include (1) ambient source apportionment, (2) elucidation of SOA composition and precursors, (3) determination of key components relevant for health and climate, (4) kinetic and mechanistic studies, and (5) infrastructural support for large-scale user facilities. More generally, the development of online instrumentation using the much-needed ultra-high resolution of the Orbitrap-MS that we propose to carry on here is groundbreaking. We expect such development to serve as a benchmark for atmospheric research and even lead to a shift in the current technology, the benefit being evident. This development will also open an entire range of new avenues for any discipline needing online ultrahigh resolution mass spectrometers, including environmental sciences, ecology, geochemistry and energy research, therefore going far beyond just atmospheric science. Currently, we are pioneering this development together with IRCELYON and acquiring an Orbitrap-MS will help us maintaining this leading position. The instrument will be shared between the laboratory of atmospheric chemistry (LAC) and the laboratory of environmental chemistry (LUC) at the Paul Scherrer Institute (PSI) and will be operated primarily by trained personnel from LAC and LUC, ensuring that the instrument will be fully exploited.