Chlorinated hydrocarbons - Fast analysis of chlorinated hydrocarbons using micro-injection technique

Importance of chlorinated hydrocarbons analysis

Chlorinated hydrocarbons are prevalent in industrial processes and can accumulate in environmental matrices, posing risks to human health and ecosystems. Fast and accurate analytical methods are crucial for routine monitoring, regulatory compliance, and rapid decision making in environmental and industrial laboratories.

Study objectives and overview

This application note demonstrates a rapid gas chromatography method using a short wide-bore fused silica column combined with micro-volume direct injection. The goal is to achieve narrow injection bands, minimize column overload, and maintain low detection limits for common chlorinated hydrocarbons.

Methodology and instrumentation used

The analysis was performed on a gas chromatograph equipped with a flame ionization detector and a valve-based micro-injection device. Key conditions included

• Column Agilent CP-Silica PLOT, 0.53 mm by 5 m, film thickness 6 µm
• Carrier gas helium at optimized flow
• Injector configured for 20 µL direct injection
• Temperature program 60 °C initial hold for 0.1 min, ramp at 70 °C/min to 250 °C
• Detector flame ionization detector with standard settings

The small injected volume yields a narrow sample band on a short column, enabling rapid separations without significant overloading.

Main results and discussion

The method successfully separated ethylene, cyclopropane, methyl chloride, vinyl chloride, and ethyl chloride within a few minutes. Representative findings include

• Baseline resolution of all target compounds
• Sharp peak shapes due to minimal band broadening
• Detection limits around 0.2 ppm
• Linear response up to at least 1000 ppm

Fast temperature ramping contributed to rapid elution while preserving chromatographic efficiency.

Benefits and practical applications

This approach offers several advantages for environmental and industrial settings:

• High sample throughput with analysis times under 5 minutes
• Reduced solvent and carrier gas consumption
• Minimal column overload even at elevated concentrations
• Sufficient sensitivity for trace-level monitoring of chlorinated organics

It is well suited for routine QA/QC, emergency response screening, and process monitoring.

Future trends and potential applications

Emerging developments may include coupling micro-injection techniques with mass spectrometric detection for enhanced selectivity, integrating automated sample introduction systems for field-deployable instruments, and applying similar strategies to other volatile organic compound classes. Further miniaturization of columns and injection hardware could improve portability and reduce analysis costs.

Conclusion

The micro-injection based fast GC method on a short wide-bore PLOT column delivers rapid, reliable separation of key chlorinated hydrocarbons with low detection limits and high throughput. Its simplicity and performance make it an attractive tool for environmental monitoring and industrial process control.

Reference

Agilent Technologies Inc Application Note A01920 Fast analysis of chlorinated hydrocarbons using micro-injection technique Environmental 2011