Improving Automated SPE Disk Extraction Technology for Semivolatile Compounds in Groundwater Using US EPA Method 8270E

Significance of the Topic

The analysis of semivolatile organic compounds (SVOCs) in groundwater is critical due to their persistence, potential toxicity, and widespread presence in environmental and consumer products. Accurate quantification supports risk assessment, regulatory compliance and source identification for pollutants including chlorinated hydrocarbons, phenols, nitrosamines, pesticides, and polycyclic aromatic hydrocarbons.

Objectives and Study Overview

This study evaluates an automated solid‐phase extraction (SPE) disk methodology using US EPA Method 8270E for simultaneous extraction of 114 neutral, acidic, and basic SVOCs from groundwater. Key performance metrics include recovery, precision, matrix spike, and demonstration of proficiency (IDP) to verify method compliance and robustness in typical groundwater matrices.

Methodology and Instrumentation

Groundwater samples (1 L) were spiked with target SVOCs and acidified to pH 2. Samples were processed on the Biotage Horizon 5000 SPE-DEX 5000 automated extractor using mixed-mode SPE disks fitted with 1 µm and 5 µm prefilters and a carbon cartridge for light‐end retention. Following disk conditioning and sample loading, a three‐phase elution sequence isolated neutral/acidic, ion‐exchange, and carbon‐bound fractions. Extracts were dried and concentrated in-line using the DryVap system. Final analysis employed GC/MS (Agilent 6890/5975) under EPA 8270E conditions.

Used Instrumentation

• Biotage Horizon 5000 SPE-DEX 5000 automated SPE extractor
• Biotage Fast Flow mixed-mode SPE disks with DualPrep filters and carbon cartridge
• Biotage DryVap inline drying and concentration system
• Agilent 6890 gas chromatograph with 5975 mass selective detector (GC/MS)

Main Results and Discussion

Initial Demonstration of Proficiency recoveries for 114 SVOCs averaged between 44 % and 129 % with standard deviations below 14 %, meeting the 50–150 % recovery range specified by EPA 8270E. Matrix spike and duplicate tests in real groundwater yielded relative percent differences below 10 % for most compounds, indicating excellent precision and negligible matrix effects. Low blank levels confirmed minimal contamination and high method sensitivity.

Benefits and Practical Applications

Automated disk‐based SPE streamlines sample preparation by combining filtration, extraction, drying, and concentration in a single workflow. The system reduces solvent usage, minimizes operator intervention, and improves throughput and consistency. It is well suited for environmental monitoring, regulatory compliance, and high‐volume laboratories performing QA/QC of water, soil leachates, and industrial effluents.

Future Trends and Opportunities

Advancements in SPE disk chemistries and smaller sample volume protocols will extend applicability to limited-volume or high‐particulate samples. Integration with laboratory information management systems (LIMS), coupling to LC/MS workflows, and field‐deployable devices are expected. Emerging needs include real‐time monitoring platforms and automated sample tracking to support smart laboratory environments and rapid response to contamination events.

Conclusion

The automated SPE disk extraction approach using Biotage Horizon 5000 and DryVap, combined with EPA 8270E GC/MS analysis, delivers reliable recoveries, high precision, and effective handling of complex groundwater samples. The methodology enhances laboratory efficiency, supports regulatory compliance, and provides a versatile platform for broad SVOC screening in environmental analysis.

References

• US EPA (2017) Method 8270E: Semivolatile Organic Compounds by Gas Chromatography/Mass Spectrometry (GC/MS).
• US EPA (2015) Method 3535A: Solid Phase Extraction, Revision A.
• Biotage Application Note AN121-HOR (2019) Automated SPE Disk Extraction of SVOCs using SPE-DEX 5000.