Extraction of a Full Suite of Semivolatile Compounds from Drinking Water using Automated Disk Solid Phase Extraction following Chinese Method SL 392-2007

Significance of the Topic

Monitoring semivolatile organic compounds (SVOCs) in drinking water is critical to safeguarding public health. Low-level contaminants can pose risks especially to vulnerable groups such as children. Regulatory frameworks around the world, including China’s SL-392-2007 method, require sensitive, reliable analytical protocols to detect and quantify dozens of SVOCs in water at microgram-per-liter levels.

Objectives and Study Overview

This application note evaluates an automated disk solid phase extraction (SPE) workflow that adheres to Chinese Method SL-392-2007 for a comprehensive panel of SVOCs in drinking water. The goals are to demonstrate recovery, precision, and throughput improvements when using high-capacity C18 disks in an automated extractor compared to traditional cartridge formats.

Methodology and Instrumentation

Water samples (1 L) were spiked with target analytes, acidified to pH <2, and dosed with surrogate and internal standards. Solid phase extraction was performed on a SPE-DEX® 5000 Automated Extractor equipped with Atlantic® C18 high-capacity disks. Conditioning, loading, rinsing, and elution steps were fully automated. Elution solvents (ethyl acetate, methylene chloride) yielded ~32 mL extract, which was concentrated to 1 mL using a DryVap® concentrator and DryDisk® membranes. Final extracts were analyzed by GC/MS on an Agilent 6890/5973 system with a ZB Semi-volatiles column (30 m × 0.35 mm, 0.25 µm).

Main Results and Discussion

Recoveries for over 100 SVOCs averaged 98.8% at a 5 µg/L spike level, with individual compound recoveries ranging 70–130%. Precision was excellent, with relative standard deviations (RSDs) typically between 1.4% and 3.6%. A direct comparison with published SL-392-2007 data showed equivalent or improved recoveries and lower RSDs for key analytes such as dichlorvos, chrysene, and dieldrin.

Benefits and Practical Applications

• Fully automated SPE reduces hands-on time and operator variability.
• High-capacity C18 disks accommodate whole water samples and particulates without clogging.
• Robust recoveries and low RSD facilitate reliable compliance testing.
• Integration of method data into LIMS supports traceability and reporting.

Future Trends and Opportunities

Emerging directions include expanding disk SPE to a broader range of polar and non-polar contaminants, adopting greener solvents and sorbents, and coupling automated extraction with high-resolution mass spectrometry for enhanced selectivity. Miniaturized SPE formats and real-time data integration will further streamline water quality monitoring workflows.

Conclusion

The automated disk SPE approach using Atlantic high-capacity C18 disks and the SPE-DEX 5000 system meets or exceeds Chinese Method SL-392-2007 performance criteria for a full suite of semivolatile compounds in drinking water. High recoveries, excellent precision, and reduced manual effort demonstrate its suitability for routine regulatory testing.

Instrumentation Used

• SPE-DEX® 5000 Automated Extractor (Horizon Technology)
• DryVap® Concentration System with DryDisk® Separation Membranes
• Atlantic® C18 High Capacity SPE Disks
• Agilent 6890 GC coupled to 5973 MSD

References

China Method SL 392-2007. Determination of Semivolatile Organic Compounds in Water by Solid Phase Extraction–Gas Chromatography/Mass Spectrometry.