Analysis of 65 Volatile Organic Compounds in Ambient Air by Canister Sampling Using an Agilent 8890/5977 GC/MSD

Importance of the Topic

Volatile organic compounds (VOCs) are key air pollutants that contribute to photochemical smog and pose health risks. Accurate monitoring of a broad range of VOCs supports regulatory compliance, ambient air quality assessment, and stringent control of semiconductor cleanroom environments. A reliable, sensitive, and reproducible analytical method for simultaneous quantification of dozens of VOCs is essential for environmental laboratories and high-tech manufacturing.

Objectives and Overview of the Study

• Validate a canister-sampling method following China’s HJ 759-2023 standard for 65 VOCs in ambient air and semiconductor cleanrooms.
• Demonstrate performance in both full-scan and selected ion monitoring (SIM) modes on an Agilent 8890 GC coupled to a 5977 single-quadrupole MSD with Markes Multi-Gas thermal desorption.
• Assess key metrics: linearity, reproducibility, and method detection limits (MDLs) for scan and SIM acquisition.

Methodology and Instrumentation

Air samples were collected in pre-evacuated, passivated canisters and humidified to 50% relative humidity. Sample volumes of 30–300 mL were thermally desorbed using a Markes Multi-Gas system (CIA Advantage-xr canister autosampler, Kori-xr water removal, Unity-xr focusing trap). Thermal desorption employed Dry Focus3 technology to remove water and concentrate analytes at –25 °C, followed by a temperature-programmed purge at 10 °C. VOCs were separated on an Agilent DB-624UI column (60 m × 0.25 mm, 1.4 µm) with He carrier gas at 1 mL/min and detected by an Agilent 5977 MSD (EI, m/z 35–500 for scan; targeted ions for SIM). Internal standards (bromochloromethane, 1,4-difluorobenzene, chlorobenzene-d5) ensured quantification accuracy.

Instrumentation Used

• Agilent 8890 gas chromatograph
• Agilent 5977 single-quadrupole MSD with electron ionization
• Markes Multi-Gas thermal desorption system (CIA Advantage-xr, Kori-xr, Unity-xr)
• Pre-evacuated passivated canisters

Key Results and Discussion

Scan Mode
• Linearity: correlation coefficients (R²) > 0.991 for all 65 compounds; 86% > 0.999.
• Reproducibility: area %RSD 0.3–6.8% across low, mid, and high calibration levels.
• MDLs: 0.013–0.113 nmol/mol for a 300 mL sample.
SIM Mode
• Linearity: R² ≥ 0.99 for all compounds; 84% > 0.999.
• Reproducibility: area %RSD 1.1–6.7% across calibration levels from 0.1 to 5 nmol/mol.
• MDLs: 0.002–0.013 nmol/mol (approximately 10× improved sensitivity versus scan).
The optimized Dry Focus3 process effectively removed residual moisture without loss of highly volatile analytes, preserving peak shape and MS response.

Benefits and Practical Applications

This canister sampling TD-GC/MSD method delivers fast, simultaneous analysis of 65 VOCs with high throughput and minimal carryover. It meets stringent environmental and semiconductor cleanroom standards. The ability to switch between scan and SIM modes provides both qualitative library matching and ultralow-level quantification in a single workflow. Robust water management extends column and source lifetimes.

Future Trends and Opportunities

Advances may include coupling canister TD to high-resolution MS for enhanced selectivity; online automated sampling in field networks; miniaturized TD modules for portable VOC monitoring; and expanded compound libraries for emerging pollutants. Integration with real-time data analytics and remote operation can further support smart environmental and factory-floor air quality management.

Conclusion

The Agilent 8890/5977 GC/MSD with Markes Multi-Gas TD provides a validated, highly sensitive, and reproducible method for comprehensive VOC analysis by canister sampling. Full compliance with HJ 759-2023 is demonstrated in both scan and SIM modes, offering a versatile solution for environmental monitoring and semiconductor cleanroom certification.

References

1. HJ 759-2023 Determination of 65 Volatile Organic Compounds–Collected in Canisters and Analyzed by Gas Chromatography/Mass Spectrometry.
2. HJ 734-2014 Stationary Source Emission–Determination of Volatile Organic Compounds–Sorbent Adsorption and Thermal Desorption GC-MS Method.
3. GB/T25915.8-2021 Cleanrooms and Associated Controlled Environments–Part 8: Classification of Air Cleanliness by Chemical Concentration.
4. Agilent Technologies Application Note 5994-7723EN, Analysis of 65 VOCs in Ambient Air by Canister Sampling Using an Agilent 8890/5977 GC/MSD.