Automated Methanol Extraction of High-Level Soil Samples Using the Teledyne Tekmar Atomx XYZ and Thermo Scientific™ TRACE™ 1310 GC and ISQ™ 7000 MS System with an ExtractaBrite Source

Significance of the Topic

Volatile organic compounds (VOCs) in high-level soil and waste samples pose significant environmental and health risks. Reliable quantification of these analytes is essential for regulatory compliance, site remediation, and risk assessment. Automating extraction and analysis enhances throughput, consistency, and data quality in environmental laboratories.

Aims and Study Overview

The study assesses an automated methanol extraction procedure for VOCs in soil using the Teledyne Tekmar Atomx XYZ purge and trap system coupled to a Thermo Scientific TRACE 1310 GC with ISQ 7000 MS and ExtractaBrite source. Key goals include establishing a linear calibration curve, evaluating accuracy and precision via an initial demonstration of capability (IDC), and determining carryover for samples with elevated analyte levels, in accordance with US EPA Methods 5035 and 8260.

Methodology and Instrumentation

Soil samples were prepared by spiking baked sand with a PVOC/GRO standard and methanol. The Atomx XYZ autosampler added methanol, mixed the sample, and transferred an aliquot for purge and trap analysis. Calibration standards ranged from 200 to 1000 ppb with four internal standards and four surrogate standards, resulting in 25 ppb in the final extract. Seven replicates of 600 ppb spiked sand were analyzed for IDC metrics. Carryover was measured by running blank sand samples after high-level injections.

Instrumentation Used

• Teledyne Tekmar Atomx XYZ purge and trap system with automated methanol extraction, moisture control, and rapid trap cooling
• Thermo Scientific TRACE 1310 GC with 20 m × 0.18 mm × 1 µm TG VMS column, helium carrier at 0.8 mL/min
• ISQ 7000 mass spectrometer with ExtractaBrite source, ion source at 280 °C, scan range 35–260 amu

Main Findings and Discussion

Calibration exhibited good linearity with response factor RSD values generally under 14%. IDC results for seven replicates at 600 ppb showed recoveries above 91% and precision better than 8% RSD. Automated extraction achieved minimal water interference and clear chromatographic separation. Carryover after high-level samples was below 0.4% for all target VOCs, demonstrating effective solvent rinse and bake cycles.

Benefits and Practical Applications

• Automated methanol extraction reduces manual handling and analysis time by up to 18% compared to prior models
• Improved moisture control extends column life and minimizes peak interference
• Reliable performance for high-concentration soil samples supports QA/QC in environmental testing and site remediation projects

Future Trends and Opportunities

Advances may include integration of artificial intelligence for data interpretation, further miniaturization of purge and trap modules, expansion to other solvent extraction protocols, and coupling with high-resolution mass spectrometry for enhanced selectivity and sensitivity.

Conclusion

The Teledyne Tekmar Atomx XYZ system combined with TRACE 1310 GC and ISQ 7000 MS provides a robust, automated workflow for VOC analysis in high-level soil, meeting EPA method requirements with high accuracy, precision, and minimal carryover. This approach streamlines regulatory compliance and improves laboratory efficiency.

References

• US EPA SW-846 Method 8260C Revision 3, Volatile Organic Compounds by GC/MS, August 2006
• US EPA SW-846 Method 8260D Revision 4, Volatile Organic Compounds by GC/MS, February 2017
• US EPA Method 5035A Revision 1, Closed-System Purge and Trap for VOCs in Soil and Waste, July 2002
• US EPA SW-846 Method 5030B Revision 2, Purge and Trap for Aqueous Samples, December 1996