A prototype of the new VOCentinel has been successfully installed and in use since June 2025 at the Innsbruck Atmospheric Observatory (IAO, University of Innsbruck).
The instrument has been fulfilling its purpose: the ongoing, long-term monitoring of volatile organic compounds (VOCs) in the ambient atmosphere.
The Ideal of Continuous, Hands-Off VOC Monitoring
We established the IAO in 2014, starting with continuous measurements of turbulence, energy, nitrogen oxides, ozone and carbon dioxide fluxes, complemented by campaigns of VOC flux measurements by PTR-TOF.
Prof. Thomas Karl, Head of the Department of Atmospheric and Cryospheric Science, University of Innsbruck
Since June, the IAO has integrated additional instruments to continuously measure fluxes of methane and ethane levels, along with nearly a dozen VOC campaigns. In the past, taking uninterrupted, high-resolution VOC measurements has been too challenging and labor-intensive.
We have been dreaming of a VOC monitor that reports concentrations of VOCs and takes care of detector tuning, calibrations, background subtractions, and other data preprocessing, just like our other online instruments. The difference is that those instruments are dedicated to one or two trace-gas species each, whereas our PTR-MS can detect thousands of VOC species, spanning many orders of magnitude in concentration and volatility.
Prof. Thomas Karl, Head of the Department of Atmospheric and Cryospheric Science, University of Innsbruck
Transport of IONICON's VOCentinel to the Atmospheric Observatory (IAO) at the University of Innsbruck. Image Credit: IONICON Analytik
From Cleanrooms to the Atmosphere: The AME Advantage
IONICON’s research and development team has long recognized the challenges of continuous VOC monitoring. IONICON has perfected this task for demanding industrial applications, including cleanroom monitoring and the semiconductor industry.
The requirements in this field are rigorous in both reliability and precision. Our industry customers do not want to merely collect data; they need actionable information in real-time. This means the critical exceedance of a specific compound must trigger a real-world procedure, such as cleaning up a solvent spill.
Jens Herbig, CTO, IONICON
With this in mind, IONICON developed the Automatic Measurement and Evaluation (AME) software, which uses different reagent ions in a repeating sequence, yielding chemical insights that far exceed the simple mass-to-charge ratios of ions.
The proprietary pattern-matching algorithm identifies chemical compounds and lowers the likelihood of false positives, which can occur due to species interferences. A core piece of software manages operational tasks and data processing.
In combination with the reliable PTR-TOFs and a genuine IONICON ion source and drift tube, this is the AME approach.
Ready for mobile deployment: the VOCentinel on its way to the IAO. Its compact footprint facilitates the transport in a standard van, highlighting its suitability for field campaigns. Image Credit: IONICON Analytik
The Challenge of Ambient Air: Thousands of VOC Species
Between cleanroom air and outdoor air samples, there are distinct differences that must be taken into account. Cleanroom air is pre-cleaned and humidity-controlled, typically containing a known suite of potential contaminants. In contrast, the latter is subject to constantly changing meteorological conditions and may contain thousands of VOC species, several of which are unidentified.
However, recent technical developments by IONICON, including the fast-switching Invion source and the Dynamic Humidity Control (DHC), now make it possible to employ IONICON’s robust AME approach towards the monitoring of VOCs in the ambient atmosphere.
Solving the Isoprene-Aldehyde Conundrum
In urban areas, various intermittent or changing sources of VOCs can make it challenging to process and understand data. This is commonly observed when “unthought-of” compounds interfere at exact masses that have traditionally been associated with a single, predominant compound.
In downtown settings, for example, research teams have demonstrated that a significant proportion of the signal at 69.070 m/z, commonly associated with protonated isoprene, may actually originate from aldehydes produced by activities such as frying or cooking.
This problem can be addressed by chemically distinguishing the aldehydes and other interfering substances from isoprene. The AME scheme, using five distinct ionization modes, provides a defining characteristic for each interfering compound, making this distinction possible.
This enables the precise identification and quantification of their components within a mixture that includes isoprene, aldehydes, and alcohols. A crucial element of the pattern-matching algorithm is its robustness, meaning it can maintain efficacy even against compounds that are unanticipated or unknown.
The VOCentinel being installed at the IAO. Image Credit: IONICON Analytik
Game Changer: Long-Term Testing and Future Impact
We are excited to have IONICON’s VOCentinel prototype deployed at IAO. This enables comprehensive long-term testing of the new instrument and unlocks valuable new insights - as effortlessly as turning a key. The VOCentinel will be a gamechanger in this community and related fields.
Prof. Thomas Karl, Head of the Department of Atmospheric and Cryospheric Science, University of Innsbruck
Ready for high-resolution, automated air monitoring? Explore the full technical specifications and capabilities of the VOCentinel.
IONICON Researcher Martin Graus and Prof. Thomas Karl have been collaborating on the deployment of the VOCentinel, the long-term testing, and the data interpretation. Image Credit: IONICON Analytik
This information has been sourced, reviewed, and adapted from materials provided by IONICON Analytik.
For more information on this source, please visit IONICON Analytik.