Consumers are becoming increasingly aware of the odors emitted by everyday products, particularly those made from plastics. From the unmistakable scent of a new car to the chemical smells in household items such as food packaging and electronics, these emissions are raising concerns about their impact on indoor air quality. Regulatory agencies are also increasing their scrutiny, as enclosed spaces—from vehicles and aircraft cabins to mobile phones and even soda bottles—can release volatile organic compounds (VOCs) that impact air quality.
Identifying and quantifying these emissions, especially in complex materials, remains a significant challenge. Caroline Widdowson, an expert in material emissions at Markes International, explains how advanced GC-MS and olfactometry techniques are helping manufacturers pinpoint the sources of these odors and ensure their products meet both consumer expectations and regulatory standards.
Why are VOCs such a critical focus for scientists and manufacturers today?
VOCs are present in a lot of the materials and products we interact with daily. Their emissions can have toxicological impacts on human health, and they often contribute to unpleasant odors. Both of these factors—health and odor—are why VOCs are becoming a major focus for scientists and manufacturers. As consumers demand safer products, companies are under increasing pressure to understand and control these emissions, whether it’s in indoor air, vehicles, or even packaging materials.
Can you explain how thermal desorption and GC-MS work in detecting VOC emissions, and why they’re so effective?
Thermal desorption allows us to pre-concentrate the sample before it enters the GC column, which is key to analyzing trace levels of VOCs. We can sample air from different environments by focusing the sample onto sorbents inside a tube. From there, we further concentrate the sample before injecting it into the GC. This technique is highly sensitive and allows us to detect VOCs over a wide dynamic range, from percent-level concentrations down to sub-part-per-trillion levels. It’s widely used for environmental monitoring but also applies to various industries that need to track emissions from materials.
Odor is a subjective experience, but it plays a big role in consumer satisfaction. How does GC-olfactometry help manufacturers identify and address odor issues in products?
Odor panels can tell you if a product smells unpleasant, but they can’t identify which specific chemical is causing the odor. That’s where gas chromatography olfactometry (GC–O) comes in. We separate the compounds using a GC column and identify them with mass spectrometry. But at the same time, we split the sample to an olfactory port, allowing us to sniff the individual compounds as they come through. This helps us pinpoint the exact compound responsible for the odor and gives manufacturers the information they need to adjust their formulations. It’s particularly useful when troubleshooting products that have an off-odor, and it’s used a lot in industries like food, fragrance, and materials.
How does two-dimensional gas chromatography (GC x GC) enhance VOC detection?
GC x GC is essential when dealing with complex samples. You often have high-concentration compounds, such as aliphatic compounds in polymers, that can mask the trace-level compounds we’re trying to detect. Two-dimensional gas chromatography provides better separation, allowing us to isolate those trace compounds more effectively. It’s especially helpful in industries where odor is important, such as food, flavor, and fragrance, but it’s also used in areas like jet fuel analysis and other petroleum products.
We’ve seen manufacturers bringing VOC testing in-house. What’s driving this trend, and how is it changing product development?
More manufacturers are taking responsibility for VOC testing in-house, driven by the need to meet regulatory demands and push product innovation. Previously, a lot of this testing was outsourced to contract labs, but now companies are investing in their own instrumentation—including thermal desorption GC-MS and GC-O—to continuously monitor their products. This helps them comply with regulations and enables them to improve their materials by producing lower-emitting products. It also speeds up research and development, as they can perform both routine screening and discovery analysis internally.
PFAS is a hot topic, especially in terms of environmental impact. How are you using VOC analysis techniques to monitor PFAS emissions?
PFAS are widely known for their heat, water, and stain resistance, but they’re also notoriously difficult to break down, which has added to raised environmental and health concerns. We’ve been working with the US Environmental Protection Agency (EPA) on methods such as OTM 50, which focuses on measuring the products of incomplete destruction when PFAS are broken down. As a material emissions specialist, I’m particularly interested in the release of PFAS from products such as waterproof clothing or food packaging. We use dynamic headspace systems to simulate real-world conditions and track the volatile PFAS compounds that are emitted, using thermal desorption GC-MS for the analysis. It’s a fascinating area, especially as more companies start moving away from PFAS coatings and explore new alternatives that also need to be tested for emissions.
Sorbent technology plays a big role in capturing VOCs. Can you explain how different sorbents are used depending on the application?
Sorbents come in various strengths and can be tailored to capture different types of VOCs. For example, strong sorbents are used to trap very volatile compounds, while medium sorbents, such as Tenax®, capture a wider range. Weaker sorbents, such as quartz wool, trap heavier, bulkier semi-volatile compounds including phthalates and polycyclic aromatic hydrocarbons (PAHs). We often combine multiple sorbents to ensure we’re capturing the full spectrum of untargeted compounds, as we often don’t know what we are looking for, whether we’re monitoring emissions from a petrochemical plant, testing materials for PFAS release, or even looking at breath samples for biomarkers of disease. This technique enables accurate analysis across a vast array of applications.
As the list of concerning VOCs and airborne particles continues to grow, staying ahead of the latest trends in emissions analysis is more important than ever. As the scope of the problem widens, adopting the latest analytical tools becomes crucial for effective detection and mitigation.
Stay up-to-date on the latest breakthroughs and practical steps in VOC analysis for polymers by watching the webinar Advanced GC-MS Techniques in Polymer Chemistry, presented by Caroline Widdowson.
Caroline Widdowson
Material Emissions Specialist, Markes International
Caroline works for Markes International, an advanced analytical instrument manufacturer. Having completed her chemistry degree at Cardiff University, she followed on with a Ph.D. in Organic Chemistry then an MBA. As part of her current role, Caroline advises manufacturers, test laboratories, and research institutes on equipment needed to monitor interior environments and study chemical emissions from materials. Caroline is the Chair of the UK BSi committee developing standard methods for the sampling and analysis of chemicals from products and materials (BSi EH2/5); she also participates in ISO, ASTM, and CEN standards and national regulatory committees relating to this area.
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