Analysis of VOCs

Significance of the topic

The accurate analysis of volatile organic compounds (VOCs) is essential for environmental monitoring, workplace safety, and quality control in pharmaceutical and chemical industries. Thermal desorption combined with gas chromatography–mass spectrometry (GC-MS) offers solvent-free sample introduction and high sensitivity for trace‐level detection of VOCs.

Objectives and overview of the study

This application note describes a method for the analysis of seven common VOCs using a Shimadzu GCMS-QP™ 2020 NX system equipped with a TD-30R thermal desorption unit and an SH-I-5Sil MS capillary column. The primary goal is to demonstrate robust peak separation, reproducible quantitation, and rapid analysis times using hydrogen carrier gas.

Methodology and instrumentation used

An overview of the instrumental setup:

• GC-MS system: Shimadzu GCMS-QP™ 2020 NX
• Thermal desorption unit: TD-30R with N₂ purge and programmable temperature control
• Capillary column: SH-I-5Sil MS (30 m × 0.25 mm I.D., 0.25 μm film thickness)
• Carrier gas: Hydrogen at 80.0 kPa (pressure control)
• Injection mode: Split (ratio 20:1)
• Column temperature program: 40 °C hold 2 min, ramp at 20 °C/min to 300 °C, hold 3 min
• Desorption parameters: Tube desorb at 280 °C for 10 min; trap cooled to –20 °C, then desorb at 250 °C for 10 min
• MS conditions: Electron ionization at 70 eV, ion source 200 °C, interface 230 °C, scan mode for qualitative and quantitative profiles

Main results and discussion

The method achieved baseline separation of toluene, ethylbenzene, m,p-xylene, styrene, o-xylene, p-dichlorobenzene, and tetradecane within an 8-minute run. Hydrogen as carrier gas provided narrower peak widths and reduced analysis time compared to helium. Signal-to-noise ratios exceeded 10:1 for low-ppb level injections. Chromatograms demonstrated excellent reproducibility (<3 % RSD retention times) and linear response over a broad concentration range.

Benefits and practical applications of the method

This protocol delivers rapid VOC screening without solvent artifacts and meets regulatory sensitivity requirements for occupational air monitoring. Its high throughput and low detection limits make it suitable for:

• Indoor and outdoor air quality assessments
• Industrial hygiene sampling
• Emission testing in manufacturing facilities
• Quality assurance in consumer product development

Future trends and opportunities for application

Emerging developments include integration of real-time data processing with AI-driven compound identification, miniaturized portable GC-MS units for field deployment, and expanded sorbent materials for a wider VOC range. Advances in hydrogen generator technology will further enhance safety and cost-effectiveness.

Conclusion

The Shimadzu GCMS-QP 2020 NX coupled with TD-30R and hydrogen carrier gas provides a fast, sensitive, and reliable platform for VOC analysis. The method’s robustness and versatility support diverse applications in environmental monitoring, industrial hygiene, and product safety.

Reference

1. Shimadzu Corporation. Application News 01-00541 (First Edition: Sep. 2023).