Determination of Volatile Organic Compounds (VOCs) present in the interiors of car by using GCMS/MS with static and dynamic headspace

Significance of the Topic

Volatile organic compounds (VOCs) are carbon-based chemicals with high vapor pressure at ambient temperature. In-vehicle cabins represent unique microenvironments where materials such as plastics, adhesives, paints and air fresheners can release VOCs at concentrations several times higher than outdoor levels. Chronic exposure to VOCs poses health risks including respiratory irritation, neurological effects and potential carcinogenicity, underscoring the need for sensitive and reliable analytical methods for in-car air quality monitoring.

Objectives and Study Overview

This study aimed to develop and partly validate a static and dynamic headspace gas chromatography‒tandem mass spectrometry (HS-GC-MS/MS) method for quantification of 17 target VOCs within vehicle interiors. By comparing static loop and dynamic trap sampling modes using Shimadzu’s HS-20 headspace sampler coupled to a GCMS-TQ8040, the work sought to assess sensitivity, precision, linearity, limits of detection (LOD) and quantitation (LOQ), and practical application to real cabin environments.

Methodology and Instrumentation

A 17-component VOC standard mixture (Restek VOC kit #30221) was used to prepare calibration levels from 5 to 500 ppb. Dynamic sampling employed RSC18 monotraps placed open inside a parked vehicle for 24 hours; static sampling used loop mode headspace injection. Samples and standards were analyzed using GCMS-TQ8040 in MRM mode, with helium as carrier gas and an Rxi-VMS column (60 m × 0.45 mm, 2.55 µm). Key headspace conditions included 90 °C oven, trap desorption at 220 °C, and 15 min equilibration. Collision energies and MRM transitions were optimized via Smart MRM.

Main Results and Discussion

Calibration curves for all 17 VOCs demonstrated excellent linearity (r2 > 0.96). Dynamic headspace sampling yielded 4–5-fold higher signal intensities compared to static mode, with LODs typically between 0.2 and 2 ppb and LOQs between 0.6 and 6 ppb. System precision for 100 ppb standards exhibited RSDs < 5% in dynamic mode and ≤ 7.8% in static mode. Analysis of cabin air extracts showed reproducible detection of toluene, ethylbenzene, o-xylene and dichlorobenzenes at concentrations ranging from ~18 to 48 ppb with sample RSDs < 15%.

Contributions and Practical Applications

• The combined static/dynamic HS-GC-MS/MS approach enables robust quantitation of trace VOCs in vehicle cabins.
• Dynamic trap sampling delivers enhanced sensitivity suitable for low-level monitoring and regulatory compliance.
• Validated parameters (linearity, precision, LOD/LOQ) support use in research, quality control and occupational safety assessments.

Future Trends and Potential Applications

Advancements may include automated multi-trap sampling for time-resolved profiling of cabin air, integration with portable GC-MS systems for on-site screening, and extension to broader classes of semi-volatile organic compounds. Coupling high-throughput HS methods with chemometric data processing could further improve source attribution and risk assessment in automotive and indoor air quality studies.

Conclusion

The developed HS-GC-MS/MS method, particularly in dynamic mode, provides a sensitive, precise and reliable tool for measuring multiple VOCs in car interiors. Its performance characteristics meet stringent criteria for trace analysis and demonstrate practical feasibility for environmental and health-related monitoring.

Used Instrumentation

• Shimadzu GCMS-TQ8040 triple quadrupole mass spectrometer
• Shimadzu HS-20 static/dynamic headspace sampler
• Rxi-VMS capillary column (60 m × 0.45 mm, 2.55 µm)
• GL Sciences RSC18 MonoTrap™ VOC adsorbent traps

References

[1] GREENGUARD Environmental Institute. A Study of Indoor Air Quality (IAQ) in Automobile Cabin Interiors. May 31, 2006.
[2] GL Science Inc. Technical Note 33: Easy Enrichment of VOCs in a New Car with MonoTrap®.