Low-Level Analysis of Epichlorohydrin in Drinking Water by Headspace Trap-GC/MS

Significance of the Topic

Epichlorohydrin is a highly reactive organochlorine used in epoxy resin and polymer production, as well as water treatment applications. Its toxicity, carcinogenic potential and strict regulatory limits—0.1 µg/L in drinking water under EU Directive 98/83/EC—demand analytical methods capable of trace-level detection without extensive sample preparation.

Objectives and Study Overview

This study aimed to develop and validate a sensitive, robust method for quantifying epichlorohydrin in drinking water at levels as low as 0.1 µg/L. The approach combines static headspace trapping with gas chromatography/mass spectrometry to meet regulatory requirements and support routine quality control.

Methodology and Instrumentation

The analytical workflow employs a static headspace trap for sample introduction and preconcentration, directly coupled via a fused-silica transfer line to a gas chromatograph. Quantification and confirmation utilize simultaneous single ion recording and full-scan mass spectrometry (SIFI mode). Calibration standards span 0.1–50 µg/L in water, enabling linear response evaluation.

Instrumentation Used

• TurboMatrix Headspace Trap sampler with adsorbent bed for preconcentration, thermally programmed from 30 °C to 300 °C
• Clarus 600 GC/MS system equipped with an Elite-WAX capillary column (60 m × 0.25 mm × 0.5 µm)
• Helium carrier gas maintained at 25 psi in the GC and headspace manifold

Key Results and Discussion

Retention time of epichlorohydrin was 10.46 min under the specified temperature program. Signal-to-noise ratios reached 1,200:1 for a 1 µg/L standard and 114:1 for a 0.1 µg/L standard in SIR mode, exceeding regulatory sensitivity needs. Calibration over 0.1–50 µg/L yielded excellent linearity (R² = 0.9993). Repeatability at the 0.1 µg/L level demonstrated an RSD of 2.17 % for six consecutive injections, confirming both precision and accuracy.

Benefits and Practical Applications

• Minimal sample preparation eliminates liquid–liquid extraction or derivatization steps.
• High sensitivity and selectivity support regulatory compliance for drinking water monitoring.
• Throughput compatible with QA/QC workflows in industrial and environmental laboratories.

Future Trends and Applications

Advances may include coupling headspace trapping with tandem mass spectrometry for enhanced selectivity, automated sample handling for higher throughput, and adaptation of the method to other volatile organic contaminants. Portable GC/MS platforms with headspace modules could enable in-field testing of water supplies.

Conclusion

The combination of static headspace trapping and Clarus 600 GC/MS offers a reliable, sensitive and efficient solution for trace-level analysis of epichlorohydrin in drinking water. The method meets stringent regulatory limits with minimal sample handling and robust analytical performance.