Proton Transfer Reaction Time-of-flight Mass Spectrometer (PTR-ToF-MS)

• Subject Area: Atmospheric Science, Oceanography and Climate Research
• Term: Funded in 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 495692966

This proposal aims to acquire a Proton Transfer Reaction Time-of-flight Mass Spectrometer (PTR-ToF-MS) for the detection of volatile organic compounds (VOC) in the atmosphere. As the core of a new Keylab at the University of Bayreuth (UBT), the instrument will be dedicated to analysing exchange processes between soil, plant and atmosphere in natural and anthropogenically impacted ecosystems. Such exchange processes are complex, intertwined between chemistry, biology and physics, and cover multiple spatial and temporal scales. We intend to tackle this challenge by combining the detection of volatile organic compounds with the observations of greenhouse gases and meteorological parameters. VOC are emitted in high number and variety by the Earth’s ecosystems, depending on species and state, temperature, irradiation and other environmental factors. This makes VOC excellent indicators to examine exchange processes between the Earth surface and the atmosphere. Proton Transfer Reaction Time-of-flight Mass Spectrometry detects non-methane VOC as well as several of their oxidation products selectively and without severe fragmentation by soft ionisation with protonated water (H3O+) or other reagents (e.g. NH4+) and with a high mass resolution via time-of-flight separation. This method provides a high temporal resolution and is robust, which is required for field measurements. The new PTR-ToF-MS will be flexibly deployed on a mobile platform in a trailer, at the field measurement stations of the BayCEER (Bayreuth Center of Ecology and Environmental Research) or in the laboratories of the University of Bayreuth. Up to date, no similar instrument exists at the University of Bayreuth. The PTR-ToF-MS will be the central analytical instrument for the newly established research group “Atmospheric Chemistry”. At the same time, the PTR-ToF-MS will be part of a Keylab and therefore is expected to initiate collaborative projects across the disciplines with a focus on environmental research.The expertise of the Bayreuth Center of Ecology and Environmental Research forms an excellent framework for the measurements of VOC and their oxidation products. It provides the possibility to embed the VOC-view into a combination of further descriptive parameters that aid to study environmental exchange processes. Therefore, the Keylab will couple the PTR-ToF-MS with analysers for greenhouse gases, a LIDAR and a weather station. With this setup, we expect to work on current and urgent research questions about exchange processes that shape our habitat in a globally changing environment.

• DFG Programme: Major Research Instrumentation
• Major Instrumentation: Proton Transfer Reaktions Time-of-Flight Massenspektrometer (PTR-ToF-MS)
• Instrumentation Group: 1700 Massenspektrometer
• Applicant Institution: Universität Bayreuth
• Leader: Professorin Dr. Anke Nölscher