Volatile Organic Compound Analysis in Water Following HJ810-2016

Importance of the Topic

The analysis of volatile organic compounds (VOCs) in water is critical for ensuring environmental safety and compliance with regulations. Headspace sampling coupled with gas chromatography–mass spectrometry (GC–MS) offers a selective and sensitive approach to detect trace-level VOCs, which are indicators of industrial pollution and disinfection by-products.

Study Objectives and Overview

This work evaluates the performance of an Agilent 8697 Headspace Sampler -XL Tray combined with an Agilent 8860 GC System and 5977B single quadrupole MSD for quantifying 55 representative VOCs in water following the Chinese HJ810-2016 standard. Key metrics such as repeatability, linearity, limits of detection (LOD), limits of quantitation (LOQ), and recovery rates were assessed.

Methodology and Instrumentation

Water samples and calibration standards were prepared by spiking deionized water with VOC stock solutions and internal standards (fluorobenzene and 1,4-dichlorobenzene-d4). Sodium chloride was added to promote VOC partitioning into the headspace. Six calibration levels were used for both full-scan (10–400 µg/L) and selected-ion monitoring (SIM) (1–40 µg/L) modes. The headspace sampler parameters included a 65 °C oven, 80 °C loop, 40-minute equilibration, and shaking at 136 rpm. The GC–MS conditions utilized an Agilent J&W DB-624 capillary column, helium carrier gas at 1.2 mL/min, split ratio 5:1, and a temperature program from 40 °C to 230 °C. MSD settings featured an inert extract ion source and acquisition range m/z 35–350 with SIM dwell times of 20 ms.

Main Results and Discussion

Key performance outcomes:

• Automated vial leak testing identified an optimal leak threshold of 0.2 mL/min, ensuring consistent sample integrity.
• MSD tuning using bromofluorobenzene met Etune criteria before each batch.
• In scan mode, six coeluting compound pairs were resolved by unique ions. Repeatability across calibration levels showed area RSDs between 0.6% and 6.2%, with an average response RSD of 1.8%.
• Linearity (10–400 µg/L) yielded R² values from 0.9947 to 1.0000; relative response factor %RSD averaged 5.2%, below the 20% threshold.
• Scan-mode MDLs ranged from 0.132 to 1.105 µg/L; LOQs from 0.44 to 3.68 µg/L, exceeding HJ810-2016 requirements.
• SIM mode enhanced sensitivity: repeatability RSDs were 0.6–4.8%; linearity (1–40 µg/L) showed R² ≥0.9987 and average RRF %RSD of 5.5%. MDLs were as low as 0.007 µg/L; LOQs down to 0.023 µg/L.
• Recovery tests on lake water spiked at mid and high levels achieved rates of 90.8%–122.3% (scan) and 90.5%–113.5% (SIM).

Benefits and Practical Applications

This method provides:

• Robust diagnostic checks for higher throughput and minimal downtime.
• High reproducibility across a broad compound range with low detection limits.
• Streamlined maintenance and user-guided features suited for routine environmental monitoring and compliance laboratories.

Future Trends and Possibilities for Application

Advancements may include integration of real-time monitoring, automated data processing with machine learning for rapid compound identification, expanded compound libraries for emerging contaminants, and further miniaturization for on-site analysis.

Conclusion

The Agilent 8697 Headspace Sampler -XL Tray coupled with the 8860 GC and 5977B MSD delivers reliable, high-throughput VOC analysis in water. Performance metrics exceed HJ810-2016 requirements in terms of repeatability, sensitivity, linearity, and recovery, making this approach suitable for environmental surveillance and quality control.

Instrumentation Used

• Agilent 8697 Headspace Sampler -XL Tray
• Agilent 8860 Gas Chromatograph
• Agilent 5977B Single Quadrupole Mass Spectrometer with inert extract ion source
• Agilent J&W DB-624 capillary column (60 m × 0.25 mm, 1.4 µm)

References

1. Szelewski, M. Environmental Volatiles using an Agilent 7697A Headspace Sampler, an Agilent 7890B GC and an Agilent 5977A series GC/MSD. Agilent Technologies Application Note 5991-2108EN, 2013.
2. Quimby, B. D.; Andrianova, A. A. Volatile Organic Compounds Analysis in Drinking Water with Headspace GC/MSD Using Hydrogen Carrier Gas and HydroInert Source. Agilent Technologies Application Note 5994-4963EN, 2022.
3. Rothweiler, B. Analysis of Volatile Organic Compounds in Environmental Waters Using the Agilent 7697A Headspace and 7890B/5977A GC/MS. Agilent Technologies Application Note 5991-3927EN, 2014.
4. Ministry of Ecology and Environment of the People’s Republic of China. HJ 810-2016: Water Quality—Determination of Volatile Organic Compounds—Headspace/Gas Chromatography Mass Spectrometry, 2016-10-01.