Halogenated hydrocarbons - Separation of volatile halogenated hydrocarbons in water on a 100 μm fused silica capillary column

Significance of the topic

Volatile halogenated hydrocarbons pose significant environmental and health concerns due to their toxicity and persistence. Rapid analysis of these compounds in water supports regulatory compliance and ensures timely detection of contamination.

Objectives and Study Overview

The primary goal of this application note is to demonstrate a fast and efficient gas chromatographic method for the separation of five volatile halogenated hydrocarbons in aqueous samples. The study showcases how an Agilent CP-Sil 43 CB capillary column achieves complete resolution in under two minutes.

Methodology and Instrumentation Used

The analysis employed capillary gas chromatography with flame ionization detection under isothermal conditions. Key parameters include:

• Column: Agilent CP-Sil 43 CB, 0.10 mm × 10 m, 0.2 µm film thickness
• Temperature: 80 °C (isothermal)
• Carrier gas: Nitrogen at 150 kPa (17.2 cm/s linear velocity)
• Injector: Split (100 mL/min) at 250 °C
• Detector: FID at 310 °C, sensitivity 5 × 10^-12 Afs
• Sample volume: 0.4 µL of water spiked at 0.1% per component

Main Results and Discussion

The method achieved baseline separation of all target analytes within two minutes. The elution order was water, dichloromethane, tetrachloromethane, 1,1,1-trichloroethane, trichloromethane, and 1,2-dichloroethane. Chromatograms showed sharp peaks and high resolution, demonstrating the column’s suitability for rapid screening. Reproducibility and sensitivity were adequate for routine environmental testing.

Benefits and Practical Applications

This fast isothermal GC-FID approach offers several advantages:

• High throughput with analysis times under two minutes
• Simplified operation using a single temperature setting
• Robust performance for routine QA/QC in environmental laboratories

Future Trends and Opportunities

Prospective developments may include coupling the method with mass spectrometric detection for lower detection limits, implementing automated sample preparation workflows, and adapting the approach for field-deployable GC instruments. Extending the methodology to other volatile organic compounds can further broaden its applicability.

Conclusion

The presented GC-FID method on a 100 µm fused silica CP-Sil 43 CB column provides a rapid, reliable, and reproducible solution for analyzing volatile halogenated hydrocarbons in water. Its simplicity and speed make it ideal for environmental monitoring and quality control applications.