Automated Methanol Extraction of High-Level Soil Samples Using the Teledyne Tekmar Atomx XYZ and Agilent 7890B GC/5977A MSD

Importance of the Topic

The analysis of volatile organic compounds (VOCs) in soil is critical for environmental monitoring and regulatory compliance. High-level VOC concentrations pose challenges that require efficient and reliable extraction methods to ensure accurate quantitation and minimal sample carryover.

Study Objectives and Overview

This study applies US EPA Method 5035 and Method 8260C to develop an automated methanol extraction workflow for high-level soil samples using the Teledyne Tekmar Atomx XYZ P&T system coupled with an Agilent 7890B GC/5977A MS. The goals include establishing calibration linearity, determining method detection limits, assessing recovery and precision, and evaluating system carryover.

Instrumentation

• Teledyne Tekmar Atomx XYZ purge and trap system
• Agilent 7890B gas chromatograph
• Agilent 5977A mass selective detector

Methodology

Soil samples (5 g and 7 g of baked sand) were spiked with a BTEX standard in methanol, mixed in capped VOA vials, and processed by the Atomx XYZ automated methanol extraction protocol. Extracts were diluted with reagent water and purged under US EPA Method 5030 conditions. The GC was configured with a Restek® VMS column and a temperature program from 35 °C to 225 °C. The MS operated in scan mode across 35–260 m/z.

Key Results and Discussion

Calibration exhibited excellent linearity with relative standard deviations below method limits. Method detection limits ranged from 0.12 to 0.31 ppb for target compounds. Both 5 g and 7 g sample sets achieved recoveries ≥94% with precision below 10% RSD. System carryover measured on un-spiked samples following high-level spikes was under 0.65%, demonstrating effective cleaning and minimal cross-contamination.

Benefits and Practical Applications

• Automated extraction reduces manual handling errors and improves sample throughput.
• High recovery and low RSD support robust quantitation for regulatory testing.
• Minimal carryover maintains sample integrity and confidence in results.

Future Trends and Opportunities

Optimization of the GC oven program can shorten cycle times and further enhance throughput. The approach may be extended to other soil matrices or VOC profiles. Integration with robotic sample handling and advanced data analytics can streamline laboratory workflows and quality assurance.

Conclusion

The combined Teledyne Tekmar Atomx XYZ automated methanol extraction and Agilent GC/MS analysis fulfills US EPA requirements for high-level soil VOC testing, delivering accurate, precise, and efficient sample processing with minimal carryover and potential for further throughput improvements.

References

1. US EPA. Method 8260D: Volatile Organic Compounds by GC/MS. Office of Solid Waste, SW-846, Revision 4, February 2017.
2. US EPA. Method 5035A: Closed-System Purge-And-Trap and Extractions for VOCs in Soil and Waste Samples. Office of Solid Waste, Revision 1, July 2002.
3. US EPA. Method 5030B: Purge and Trap for Aqueous Samples. Office of Solid Waste, SW-846, Revision 2, December 1996.