USEPA Method 8260C using the Tekmar Atomx Automated VOC Sample Prep System and a Thermo Focus/DSQ™ II GCMS

Importance of the Topic

The analysis of volatile organic compounds (VOCs) in environmental matrices is critical for water quality monitoring, soil contamination assessment, and regulatory compliance. USEPA Method 8260C is a widely accepted protocol for trace-level quantification of VOCs. Implementing automated sample preparation enhances laboratory throughput while maintaining data quality and method compliance.

Objectives and Study Overview

This study evaluates the performance of the Tekmar Atomx Automated VOC Sample Prep System coupled to a Thermo Focus GC and DSQ II MS for water and soil analysis following USEPA Method 8260C guidelines. Key goals include generating calibration curves, determining method detection limits (MDLs), and assessing precision across a suite of 94 target analytes.

Methodology

Sample preparation followed EPA Methods 5030/5035 for aqueous and solid matrices. Water standards ranged from 0.5 to 200 ppb; soil standards ranged from 1 to 200 ppb with in-vial purge. An internal standard/surrogate mixture was automatically spiked into each sample.

Instrumental Setup

GC–MS conditions included:

• Column: Restek Rtx-VMS (20 m×0.18 mm×1 μm)
• Oven program: 40 °C (4 min), 16 °C/min to 100 °C, then 25 °C/min to 200 °C (3 min)
• Carrier gas: Helium at 1.0 mL/min
• Purge-and-trap: #9 U-shape trap, 5 mL water purge, 5 g soil with 10 mL water for in-vial purge
• MS: Electron impact ionization, source 230 °C, scan range 35–270 m/z

Main Results and Discussion

Calibration curves were linear (R² > 0.99) across both matrices. MDLs for most VOCs were 0.5 ppb in water and 1 ppb in soil, meeting EPA criteria. Relative standard deviations of response factors were generally below 12%. Representative chromatograms for 50 ppb water and soil spikes confirmed peak resolution and retention consistency.

Benefits and Practical Applications

• High throughput: 80-position autosampler for multi-matrix runs.
• Automation: Consistent purge-and-trap and vial handling reduces manual errors.
• Regulatory compliance: Method 8260C validation ensures defensible data for environmental monitoring, remediation studies, and quality assurance/control.

Future Trends and Applications

Emerging developments may include integration with high-resolution MS for non-target screening, on-site portable purge-trap systems, and further automation of data processing. Coupling Method 8260C workflows with real-time digital reporting and artificial intelligence for anomaly detection could enhance environmental surveillance.

Conclusion

The Tekmar Atomx system combined with the Thermo Focus/DSQ II GC–MS platform provides robust, automated VOC analysis in water and soil matrices in full compliance with USEPA Method 8260C. The study demonstrates reliable sensitivity, precision, and operational efficiency essential for modern environmental laboratories.

References

1. USEPA Method 5030: Purge-and-Trap for Aqueous Samples, Revision 3, May 2003.
2. USEPA Method 5035: Closed-System Purge-and-Trap for Soils and Waste, Revision 1, July 2002.
3. USEPA Method 8260C: Volatile Organic Compounds by GC/MS, Revision 3, August 2006.