Analysis of Volatile Organic Compounds in Water and Soil by EPA Method 8260 with the Atomx Concentrator/Multimatrix Autosampler

Importance of the topic

Volatile organic compounds (VOCs) pose health and environmental risks in water and soil, requiring accurate quantification at trace levels.
Purge and trap coupled with gas chromatography–mass spectrometry (GC/MS) remains a gold standard for ppb-level detection.

Objectives and Study Overview

The study evaluated Teledyne Tekmar’s Atomx concentrator/multimatrix autosampler under USEPA Method 8260 for simultaneous analysis of 95 VOCs in water (0.5–200 ppb) and soil (1.0–200 ppb).
Linearity, sensitivity, and compliance with regulatory performance criteria were assessed using standardized purge volumes and simulated soil slurries.

Methodology and Instrumentation

Sample introduction followed EPA preparative methods, with 5 mL purge for water and a 10 mL soil slurry.
Purge & trap conditions adhered to Method 8260, featuring ambient sparge, trap desorption at 250 °C, and inert transfer.
Chromatography used a 30 m × 0.25 mm DB-VRX column with temperature ramp from 35 °C to 210 °C.
Mass spectrometry scanned m/z 35–300 at ~5 scans/sec.

Used instrumentation

• Atomx purge & trap concentrator/multimatrix autosampler with proprietary #9 U-shaped trap and 80-position carousel
• Agilent 7890A gas chromatograph
• Agilent 5975C inert XL mass spectrometer
• J&W Scientific DB-VRX capillary column (30 m × 0.25 mm, 1.4 μm)
• Helium as carrier gas

Main results and discussion

Calibration curves for all 95 analytes exhibited linear response and met EPA 8260 performance criteria in both matrices.
Method detection limits (MDLs) calculated from replicate low-level standards were generally below 0.5 ppb, demonstrating sub-ppb sensitivity.
Representative 50 ppb chromatograms showed clean peak resolution with minimal water interference and low carryover.

Benefits and practical applications

• Integration of autosampler and concentrator simplifies system setup and control
• Proprietary trap design enhances water removal and analyte recovery
• Siltek-coated flow paths reduce carryover and improve sample integrity
• High sample capacity and multiple spiking vessels boost throughput and flexibility
• Advanced rinse options (needle, methanol, hot water bake) maintain low background levels

Future trends and potential applications

Ongoing developments may include expanded matrix compatibility (e.g., sediments, sludges) and enhanced trap materials for improved sensitivity.
Automation of QA/QC processes and application of data analytics could further streamline VOC monitoring workflows.
Integration with real-time data platforms may support rapid environmental decision-making.

Conclusion

Teledyne Tekmar’s Atomx P&T concentrator and autosampler combined with GC/MS provides a robust, sensitive, and efficient system for EPA Method 8260 analysis of VOCs in water and soil, meeting regulatory requirements and facilitating high throughput.

Reference

• USEPA Method 8260B, Volatile Organic Compounds by Gas Chromatography/Mass Spectrometry, Revision 2, December 1996