Determination of Volatile Compounds in Automotive Interior Materials by Thermal Desorption GC-MS

Significance of the Topic

Indoor air quality in new vehicles is a rising concern due to elevated levels of volatile organic compounds (VOCs) emitted from interior materials. Assessing these emissions is critical for consumer health and regulatory compliance, especially under standards such as VDA278 and China’s passenger air quality guidelines. Reliable quantification of VOCs and total VOCs (TVOCs) enables manufacturers and material suppliers to screen raw materials and finished components, ensuring safer cabin environments.

Objectives and Study Overview

This study implements the first phase of the VDA278 standard (2002) to determine VOC emissions from common automotive interior polymers. Focused on the thermal desorption–gas chromatography–mass spectrometry (TD-GC-MS) approach, it evaluates both individual benzene, toluene, ethylbenzene, and xylenes (BTEX) compounds and the overall TVOC content in representative leather and sponge samples obtained from local automotive accessory markets.

Methodology

Samples (~30 mg) of polymeric materials (ABS, PVC, leather, sponge) were cut, loaded into Tenax TA–filled glass sorbent tubes, and thermally desorbed at 90 °C for 30 min. Evolved vapors were refocused in a cold trap (–30 °C) then rapidly heated (100 °C/s) to 300 °C. The desorbed analytes were separated on a 60 m TraceGOLD TG-5MS column under a stepped oven program (40 °C to 320 °C) and detected by single-quadrupole MS via full-scan electron ionization (70 eV, 29–450 Da). Calibration used toluene standards and BTEX mixtures (10–1000 ng/µL) injected into Tenax tubes. TVOC quantification was based on integrated peak areas between n-hexane (C6) and n-hexadecane (C16), expressed as toluene equivalents.

Used Instrumentation

• Markes TD-100 Automated Thermal Desorber
• Thermo Scientific TRACE 1310 Gas Chromatograph
• Thermo Scientific ISQ LT Single Quadrupole Mass Spectrometer
• Tenax TA sorbent tubes

Main Results and Discussion

BTEX levels in leather reached up to 16.24 µg/g (toluene) with a total TVOC of 185.70 µg/g. Sponge samples exhibited lower emissions (toluene 7.99 µg/g, TVOC 76.45 µg/g). Calibration exhibited high linearity (R² ≥ 0.9990) across the tested concentration range. Chromatograms illustrated clear separation of target analytes and defined retention windows for TVOC integration. Differential emission profiles underscore the influence of material composition on VOC release.

Benefits and Practical Applications

This TD-GC-MS workflow offers:

• High sensitivity and reproducibility for VOC and TVOC measurement
• Fully automated sampling and analysis to support high throughput QA/QC
• Compliance with automotive industry standards (VDA278, GMW15634)
• Actionable data for material selection and formulation optimization

Future Trends and Applications

Emerging method improvements include expanded compound libraries for semi-volatile organics (SVOCs), miniaturized sampling devices for in-situ cabin monitoring, and coupling with real-time detectors. Integration of advanced data analytics and machine learning can further predict long-term emission profiles and guide material innovation for lower-emitting interiors.

Conclusion

The described application confirms that automated TD-GC-MS analysis adhering to VDA278 standard reliably quantifies VOC and TVOC emissions from automotive interior materials. The approach supports manufacturers in maintaining cabin air quality and meeting stringent global regulations.

References

1. Grabbs J., Corsi R., Torres V. Volatile Organic Compounds in New Automobiles: Screening Assessment. J. Environ. Eng. 126(10):974–977 (2000).
2. Lee C. New Chinese guidelines for car interior air quality to come into effect tomorrow. Gasgoo.com (2013).
3. VDA 278. Thermal Desorption Analysis of Organic Emissions for the Characterization of Non-Metallic Materials for Automobiles. Verband der Automobilindustrie, Germany (October 2011).
4. GM Engineering Standards GMW15634. Determination of Volatile and Semi-Volatile Organic Compounds from Vehicle Interior Materials. General Motors (Jan 2008).