Analysis of Organ-halogenated Hydrocarbons by Solvent Extraction Method

Significance of the Topic

Organ-halogenated hydrocarbons are widespread environmental contaminants originating from industrial solvents, degreasers and chemical manufacturing. Their persistence and potential health risks make accurate monitoring in water crucial. Gas chromatography coupled with flame ionization detection (GC–FID) remains a standard approach due to its robustness, sensitivity and wide availability in analytical laboratories.

Objectives and Study Overview

This application note presents a rapid GC–FID method for simultaneous quantification of eight common organochlorine and organobromine compounds in water samples following solvent extraction. The goals were to achieve clear separation, reliable quantitation and concise run times to facilitate routine monitoring of water pollutants.

Methodology and Instrumentation

The procedure employs liquid–liquid extraction of water samples into an organic solvent, followed by GC–FID analysis on a wide-bore column. Key instrumental parameters include:

• Gas chromatograph: Shimadzu GC-FID system
• Column: SH-624, 30 m × 0.53 mm I.D., 3.0 µm film thickness
• Oven temperature program: hold at 40 °C for 7 min, ramp 10 °C/min to 120 °C, hold 5 min
• Injector temperature: 220 °C, injection volume 1 µL via packed-column injector with wide-bore connector
• Carrier gas: helium at 7 mL/min (flow controlled)
• Makeup gas: nitrogen at 250 mL/min
• Detector: FID at 220 °C

Main Results and Discussion

The optimized method achieved baseline separation of eight target analytes within a 15-minute cycle. Retention order and approximate elution times were:

1. Chloroform
2. 1,1,1-Trichloroethane
3. Tetrachloromethane
4. Trichloroethylene
5. Bromodichloroethane
6. Tetrachloroethylene
7. Dibromochloromethane
8. Bromoform

Chromatographic peaks were sharp and well resolved, demonstrating the suitability of the SH-624 wide-bore column for halogenated volatiles. The flame ionization detector provided consistent response factors and low detection limits.

Benefits and Practical Applications

This GC–FID approach offers:

• High throughput: <15 min per run
• Reliable quantitation: excellent peak resolution
• Broad applicability: suitable for environmental and industrial water testing
• Accessibility: uses standard GC–FID instrumentation

Laboratories can implement this method for routine screening of groundwater, surface water and industrial effluents to comply with regulatory requirements.

Future Trends and Potential Applications

Advancements may include coupling GC to mass spectrometry for confirmatory analysis, development of more selective stationary phases, miniaturized portable GC systems for field monitoring and greener extraction techniques (e.g., solid-phase microextraction). Integration with automated sample preparation could further enhance throughput and reproducibility.

Conclusion

The described GC–FID protocol on an SH-624 wide-bore column delivers fast, accurate and robust analysis of key organ-halogenated hydrocarbons in water. Its simplicity and efficiency support routine environmental monitoring and quality control in diverse laboratory settings.