Emerging contaminants, complex industrial emissions and rapidly evolving regulatory landscapes require cutting-edge analytical solutions. Alongside these industry dynamics, assessing air quality has been essential for protecting public health and understanding environmental impacts, and the need for real-time, ultra-sensitive and selective detection technologies will increase.
Advanced Proton Transfer Reaction Time-of-Flight Mass Spectrometry (PTR-TOF-MS) and Aerosol Ionization Mass Spectrometry (AIMS) technologies are transforming combustion optimization, ambient monitoring and emissions monitoring. These state-of-the-art instruments deliver unparalleled sensitivity, specificity and real-time analysis capabilities, enabling precise control over combustion processes and emissions characterization. This data is critical when considering regulations, determining sample quantities for laboratory analysis and mitigation needs planning.
The Transformative Capability of Real-Time Air Monitoring Technology
PTR-TOF-MS and AIMS technologies are transforming combustion optimization, ambient monitoring and emissions monitoring. The ability to actively measure products of incomplete combustion/destruction, or unlabeled PFAS intermediates, precursors and ultra-short-chain components, provides field intelligence and the ability to make quicker, more informed decisions.
These advanced instruments detect, quantify and characterize volatile and semi-volatile organic compounds (VOCs and SVOCs) and volatile per-and polyfluoroalkyl substances (PFAS) and precursors in real time, down to sub-parts-per-trillion (ppt) levels. This type of technology in the field can determine where and the extent of the issue prior to the first sample being sent to the laboratory, saving crucial time while minimizing labor-intensive manual methods.
The real-time measurement capabilities of PTR and AIMS technologies provide customers, for the first time, with actionable intelligence directly in the field. These advanced tools enable informed decision-making across many aspects of a project. For example, users can determine how many samples to submit to traditional brick-and-mortar laboratories or assess the extent of contamination on site. In addition, these technologies offer insight into compliance status with emerging regulations for ambient air or fence line concentrations of target compounds, including flux measurements.
Data can be collected for either engineering or compliance purposes, depending on the customer’s needs. Engineering data can guide decision-making without triggering Notices of Violation (NOVs). These technologies surpass the capabilities of current reference methods and allow users to optimize their processes before formal compliance testing begins. Much like how older technologies—once considered cutting-edge, such as Fourier Transform Infrared (FTIR) Spectrometry—are now seen as rudimentary; PTR and AIMS represent the future of emissions measurement.
How the Technology Works
PTR-TOF-MS
PTR-TOF-MS is a real-time, direct-injection mass spectrometry technique that ionizes organic molecules using H₃O⁺ (hydronium) ions under carefully controlled conditions. These ions transfer protons to most VOCs with high efficiency but do not react with major air constituents such as N₂, O₂, or CO₂, enabling highly selective and sensitive detection of trace contaminants.
The benefits of PTR-TOF-MS instrumentation include:
- Ultra-low detection limits (<1 parts-per-trillion for many VOCs)
- High time resolution (sub-second), ideal for fence line, mobile or stack testing
- Isobaric resolution, enabling separation of compounds with similar molecular weights
- Can assess 500+ compounds simultaneously
- No need for sample preparation, significantly reducing turnaround time
PTR-TOF-MS can be deployed for a range of applications:
- PFAS precursor detection (e.g., fluorinated aldehydes, ketones, alcohols)
- Odor source identification at wastewater and industrial facilities
- Real-time emissions tracking at fence line and mobile platforms
- Chemical process optimization and leak detection
Soft Fragmentation Mass Spectrometry (CIMS and AIMs)
While PTR-TOF-MS excels at detecting volatile organic compounds, soft-fragmentation mass spectrometry techniques can extend to a broader array of compounds—especially those that may fragment destructively in traditional ionization methods. There are two types of soft fragmentation mass spectrometry:
- Chemical Ionization Mass Spectrometry (CIMS) uses reagent ions such as iodide (I⁻), acetate, or nitrate (NO₃⁻) to gently ionize compounds via charge transfer, clustering or adduct formation. This method preserves the molecular structure of fragile or complex compounds, enabling:
- Measurement of highly oxidized or functionalized VOCs
- Real-time detection of low-volatility PFAS degradation products
- Differentiation of isomers and molecular classes in ambient air
- Over 30 volatile PFAS and precursors
- AIMs (Aerosol Ion Mobility Spectrometry), when paired with CIMS, provide a powerful tool to characterize both gas-phase and particle-bound contaminants. By combining mass-to-charge ratios with mobility information, AIMs enable chemical speciation of ultrafine aerosols and semi-volatile compounds—an emerging area of interest in PFAS, odor and air quality studies.
Applicability
Companies are facing PFAS regulations, challenging odor complaints and the need for ultra-low and accurate target compound measurements, requiring rapid source identification and rapid, precise data. Mass spectrometry tools offer a solution, delivering data in seconds. These tools enable dynamic process control in industrial settings, rapid response to regulatory exceedances or community concerns and forensic-level analysis of complex emissions plumes. These mobile systems can be deployed on-site at refineries, wastewater treatment plants, landfills and manufacturing facilities, offering clients actionable insights during investigations or compliance assessments.
Innovative Technologies at TRC
As a leader in digital solutions, these innovative technologies represent the forefront of atmospheric and source emission analysis and are now fully operational as part of TRC’s field-deployable and laboratory-based environmental testing solutions.
Our investment in state-of-the-art instrumentation and cross-disciplinary expertise provides integrated solutions. TRC’s scientists, chemists and engineers collaborate to design customized monitoring strategies that combine PTR-TOF-MS, CIMS and AIMs, traditional lab methods (EPA 325, OTM-45, OTM-50, EPA TO-15, 533 and 1633) and meteorological and dispersion modeling tools.
These capabilities are backed by our in-house PFAS experts and environmental field services personnel, who are trained to deploy these platforms safely and effectively across the country. Integrating a traditional approach with real-time instrumentation capable of ultra-low detection limits (part per trillion) and detecting products of incomplete combustion or destruction (PICs/PIDs) enables more cost-effective solutions and field intelligence enabling projects to proceed efficiently and effectively.
TRC’s PTR-TOF-MS and soft ionization capabilities represent a critical step forward—empowering our clients with the data they need to stay ahead of compliance, community expectations and environmental responsibility.
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