Ultra-Fast GC Meets Mass Spec: Measuring Forest Chemicals That Create Storm Clouds

Austin "Augie" Dobrecevich is a PhD researcher at the University of Washington who built an ultra-fast gas chromatograph small enough to fit in a carry-on suitcase — paired with a portable time-of-flight mass spectrometer — to measure biogenic VOCs like alpha-pinene, beta-pinene, and limonene straight from a forest canopy in real time.

In this episode, Augie takes us inside his summer deployment on a 43-meter tower in northern Alabama, where he captured a chromatogram every second to track how forest terpenes react in the atmosphere and seed the massive thunderstorms the region is known for. We dig into:

• Why ultra-fast GC sub-second separations matters for atmospheric chemistry and chemical ionization mass spec (CIMS)
• How isomer-specific data solves a blind spot in direct-inlet CIMS instruments
• The engineering trade-offs behind building a 300-watt, TOF-based system for field deployment
• Potential applications in oceanography, coral reef VOC sampling, and contaminant screening
• His path through the patent process at UW's CoMotion tech transfer office — provisional patents, IP strategy, and the Innovation Gap Fund
• Lessons from pitching a science-heavy invention to a business audience, and advice for grad students on cross-disciplinary PhD paths

Whether you're an analytical chemist, an atmospheric scientist, or a grad student weighing the leap from bench science to commercialization, this conversation covers the technical depth and the entrepreneurial reality of turning a lab prototype into a real instrument.

Video Transcription

What if a gas chromatograph could deliver a complete separation every second, even while operating more than 40 metres above a forest canopy? Austin “Augie” Dobrecevich, a doctoral researcher at the University of Washington, is helping develop a compact ultra-fast gas chromatography system coupled to chemical ionization time-of-flight mass spectrometry (GC–CI-TOFMS). The goal is to measure rapidly changing atmospheric compounds while retaining the ability to distinguish chemical isomers.

Why conventional GC is not always fast enough

Traditional gas chromatography offers powerful chemical separation, but analyses that take many minutes cannot fully capture processes changing from second to second. Dobrecevich's interest in faster measurements grew from his work with Robert Synovec's research group, particularly the rapid second-dimension separations used in comprehensive two-dimensional gas chromatography (GC×GC).

Developing chromatography on a sub-second timescale required careful attention to injection performance, dead volumes and extra-column band broadening. The team focused on producing short, reproducible injection pulses and efficient separations of targeted mixtures. Unlike conventional methods designed to resolve hundreds of compounds, the ultra-fast approach prioritizes a smaller set of analytes and repeated measurements at very high temporal resolution.

This becomes especially valuable when combined with chemical ionization mass spectrometry (CIMS). Direct-inlet CIMS can monitor volatile compounds rapidly and sensitively, but mass spectra alone often cannot distinguish structural isomers sharing the same molecular formula. Adding ultra-fast GC provides an additional separation dimension without losing the one-second measurement timescale.

Measuring forest emissions from a 43-metre tower

The prototype was deployed at a US Department of Energy research site in northern Alabama, where Dobrecevich installed it on a 43-metre tower above a forest canopy. The hot, humid environment offered a demanding test of the instrument's reliability outside the laboratory.

The study focuses on biogenic volatile organic compounds (BVOCs) released by trees, particularly monoterpenes such as α-pinene, β-pinene and limonene. Although these compounds have the same molecular formula, their structures and atmospheric reaction pathways differ. Rapid chromatographic separation allows researchers to follow how the concentrations of individual monoterpene isomers change with wind direction, atmospheric mixing and environmental conditions.

The instrument's sampling inlet was positioned near a sonic anemometer, which measures wind velocity in three dimensions. Combining these measurements with one-second chemical data is intended to support flux analysis, helping researchers investigate how compounds move between the forest canopy and the atmosphere.

Monoterpenes can react with atmospheric oxidants to form lower-volatility products that contribute to secondary organic aerosols and potentially to cloud condensation nuclei. Understanding the emissions and chemistry of individual isomers could therefore improve models of atmospheric processes.

A portable GC–MS system with low power requirements

To make these measurements possible in remote locations, the researchers combined their custom-built ultra-fast GC with a compact chemical ionization time-of-flight mass spectrometer developed with Swiss instrument manufacturer TOFWERK.

According to Dobrecevich, the integrated system is approximately the size of a carry-on suitcase and operates at less than 300 W.

The portable mass analyzer has a reported resolving power of approximately 1,300 (m/Δm). Although this is lower than that of many larger high-resolution TOF instruments, chromatographic separation helps compensate for the reduced mass selectivity by resolving isomers before they enter the ion source. The result is a promising balance between speed, selectivity, instrument size and power consumption.

The Alabama deployment was designed primarily to stress-test this early-stage prototype and demonstrate the feasibility of isomer-resolved flux measurements. It does not yet establish a routine commercial method, but it shows why compact GC–MS technology could open up experiments that previously required difficult compromises between chemical specificity and measurement speed.

Applications beyond atmospheric research

While forest emissions are the current focus, the underlying concept could be useful wherever chemical compositions change rapidly. Potential applications include mobile monitoring of urban air pollutants, targeted screening of industrial emissions, process control and rapid detection of selected contaminants.

Dobrecevich also sees opportunities in marine research. Volatile compounds released from seawater or biological samples could potentially be transferred into the gas phase and analyzed close to the sampling site, reducing delays associated with sample transport and storage. These remain prospective applications for the GC-coupled prototype rather than established workflows.

Moving from research to commercialization

Developing the instrument has also introduced Dobrecevich to intellectual property and technology transfer. With support from the University of Washington's CoMotion program, the team pursued a provisional patent before publicly disclosing key elements of its design.

The project subsequently received approximately $75,000 through an Innovation Gap Fund award, helping support further development and field testing.

An important lesson has been that technical performance alone does not establish commercial demand. Through planned customer-discovery activities, including the NSF I-Corps program, the team aims to understand where rapid, isomer-specific measurements solve genuine laboratory or field-analysis problems.

For Dobrecevich, interviewing prospective users without leading them toward a desired answer is as important as testing a scientific hypothesis.

A lesson in interdisciplinary science

Dobrecevich's path from chemistry into atmospheric instrumentation also highlights the value of working across disciplines. Advances in field-deployable analytical systems depend on chromatography, mass spectrometry, engineering, physics and environmental science, often developed through close collaboration between specialists.

The broader significance of ultra-fast GC is not simply shorter analysis time. By matching chromatographic measurements to the speed of real-world processes, researchers may gain access to chemical information that conventional laboratory workflows cannot capture.

This text has been automatically transcribed from a video presentation using AI technology. It may contain inaccuracies and is not guaranteed to be 100% correct.

Concentrating on Chromatography Podcast

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