Analysis of VOCs and Petroleum Hydrocarbons (C6 to C9) in Soil and Sediment with a P&T-8890 GC/FID/5977 MSD System

Importance of the Topic

Soil and sediment contamination by volatile organic compounds (VOCs) and light petroleum hydrocarbons poses significant risks to groundwater quality and land usability. Regulatory standards such as China’s HJ 605-2011 and HJ 1020-2019 methods drive the need for reliable, high-throughput analysis workflows in environmental laboratories.

Objectives and Study Overview

This study aimed to demonstrate a unified purge-and-trap gas chromatography configuration, combining an Agilent 8890 GC equipped with flame ionization (FID) and mass spectrometric (MSD) detectors, to simultaneously meet the performance criteria of HJ 605-2011 (VOCs) and HJ 1020-2019 (C6–C9 hydrocarbons). Key goals included validating linearity, repeatability, method detection limits, and recovery for both compound classes on a single analytical platform.

Methodology and Instrumentation

Samples were prepared by spiking soil with target analytes and internal standards, followed by automated purge-and-trap extraction using a Teledyne Tekmar Atomx XYZ system. Chromatographic separation employed an Agilent DB-624 Ultra Inert capillary column in two oven programs: the shorter HJ 605 VOC temperature ramp (20 min) and the extended HJ 1020 hydrocarbon ramp (35 min). A split effluent delivered analytes equally to the FID and an Agilent 5977B MSD operating in SCAN mode. Data processing used internal-standard quantification for VOCs (MSD channel) and area summation for C6–C9 hydrocarbons (FID channel).

Main Results and Discussion

For 65 VOCs, calibration curves over 5–200 µg/L showed R² > 0.994 with method detection limits below 1.1 µg/kg for most compounds. Seven-point repeatability tests at 20 µg/L yielded RSDs of 0.6–5.5%, meeting HJ 605 criteria. Recovery studies in two soil matrices averaged 85–113%. In the petroleum hydrocarbon assay, six-level calibration from 0.1 to 6 µg/mL produced R² = 0.9997, RSDs < 3.7%, and a detection limit of 0.02 mg/kg. Sample analyses confirmed accurate quantitation of VOCs and C6–C9 hydrocarbons, though co-eluting VOCs can interfere in hydrocarbon assays if using a single FID channel.

Benefits and Practical Applications

This unified GC/FID/MSD approach reduces capital and maintenance costs by eliminating the need for separate instruments. Laboratories can achieve either separate or high-throughput combined analyses: a single 20-minute run for VOC-dominant samples or a 35-minute run for hydrocarbon-dominant samples, with dual detection for cross-confirmation. The flexible configuration supports real-time decision making in environmental monitoring and site assessment.

Future Trends and Applications

Emerging needs include integrating automated data evaluation and AI-driven peak identification to further streamline laboratory workflows. Advances in column technology and detector sensitivity may expand the unified platform to heavier hydrocarbons and emerging pollutants. Coupling with remote sampling and cloud-based reporting systems will enhance rapid response capabilities in contaminated site management.

Conclusion

The combined Teledyne Tekmar Atomx XYZ P&T–Agilent 8890 GC/FID/5977B MSD configuration effectively satisfies both HJ 605-2011 and HJ 1020-2019 analytical requirements on a single instrument. It delivers robust linearity, precision, sensitivity, and recovery for VOCs and C6–C9 hydrocarbons, while offering flexible runtimes for routine and high-throughput applications.

References

• HJ 605-2011: Soil and Sediment—Determination of Volatile Organic Compounds—Purge and Trap Gas Chromatography/Mass Spectrometry Method
• HJ 1020-2019: Soil and Sediment—Determination of Petroleum Hydrocarbons (C6–C9)—Purge and Trap Gas Chromatography