Identification of VOCs in In-Vehicle Interior Using TD-GC/MS-Olfactory Port

Importance of the topic

The performance and sensory quality of new vehicles are significantly influenced by volatile organic compounds (VOCs) emitted from interior materials. Beyond consumer perception of “new car smell,” many VOCs pose health risks, including carcinogenic or neurologic effects. Combining chemical analysis with sensory evaluation allows automotive developers to identify odor-causing compounds and guide material improvements.

Objectives and study overview

This work presents a combined thermal desorption gas chromatography/mass spectrometry (TD-GC/MS) approach with an integrated olfactory port to achieve simultaneous chemical identification and odor characterization of VOCs emitted from in-vehicle interior components. It aims to provide qualitative profiles of emissions and correlate specific compounds to sensory impressions in a single automated run, facilitating rapid feedback to materials suppliers.

Methodology and instrumentation

Samples such as dashboard panels, seat materials, door seals, and luggage compartment liners were prepared according to ISO/FDIS 12219-2 by placing specimens in sealed sampling bags, heating to 60 °C for 2 h, and drawing 5 L of headspace onto Tenax tubes. Thermal desorption was performed on a PerkinElmer TurboMatrix 650 ATD coupled to a Clarus SQ 8 GC/MS with an SNFR™ olfactory port via an S-Swafer™ splitter. Key operating parameters included:

• Desorb temperature: 280 °C; trap at –30 °C to 280 °C ramp;
• Column: 60 m × 0.25 mm × 1 μm 5MS, 50 °C initial to 280 °C at 5 °C/min;
• MS scan range: 35–350 amu; scan time 0.25 s;
• Olfactory port flow: 500 mL/min humidified air at 37 °C.

Key results and discussion

Total ion chromatograms of door seal assemblies, sealing strips, luggage liners, and door panels revealed diverse classes of VOCs. Rubber seals emitted aromatics, ketones, esters, and amines linked to strong burnt or ammonia-like odors. Carbon disulfide dominated some profiles with a rotten-egg smell. Luggage compartment materials released alkanes, alkenes, and acids presenting floral to acidic notes. Door panels emitted high levels of ethyl acetate, methylcyclohexane, and aromatics with fruity or burnt odor.
Seat component analysis identified triethylenediamine (ammonia odor), bis(2-dimethylamino)ethyl ether (foam catalyst, aromatic odor), and polysiloxanes (foam stabilizers, mild aromatic). Correlating MS library matches to recorded olfactory observations enabled precise mapping of chemical sources to perceived odor intensity.

Benefits and practical applications

This integrated TD-GC/MS-olfactory port approach:

• Delivers simultaneous chemical and sensory profiles in one analysis, reducing time and resources.
• Pinpoints key odor contributors for targeted material reformulation.
• Supports compliance with VOC emission regulations and enhances in-vehicle air quality.

Future trends and opportunities

Advancements may include quantitative odor thresholds linked to GC calibration, expanded olfactory databases, machine-learning models to predict sensory impact, and real-time monitoring systems for in-process material screening. Integration with regulatory frameworks and industry standards will drive broader adoption in automotive and other odor-sensitive sectors.

Conclusion

The combination of TD-GC/MS with an olfactory port offers a robust platform for comprehensive VOC emission and odor assessment of vehicle interiors. By coupling chemical identification with sensory data, automotive engineers can systematically address odor issues, improve passenger comfort, and ensure safer cabin environments.

Reference

ISO/FDIS 12219-2, Interior air of road vehicles – Part 2: Screening method for the determination of the emissions of volatile organic compounds from vehicle interior parts and materials – Bag method, 2012.