Organochlorine Pesticide Mix AB #2 Rtx®-CLPesticides and Rtx®-CLPesticides2 (0.25mm ID column set)

Significance of the Topic

Organochlorine pesticides remain persistent environmental contaminants with potential health impacts. Their accurate quantification in environmental and food matrices is critical for regulatory compliance, risk assessment and ensuring public safety.

Objectives and Study Overview

This study demonstrates a robust gas chromatography–electron capture detection (GC-ECD) method for simultaneous analysis of 22 organochlorine pesticides using a dual capillary column arrangement. The target analytes include aldrin, dieldrin, chlordane isomers, DDT and related breakdown products.

Methodology and Instrumentation

The sample, Organochlorine Pesticide Mix AB #2 combined with an EPA surrogate mix, is introduced via splitless injection (0.5 µL) on a Cyclo double-taper liner at 250 °C. Chromatographic separation employs two Restek columns (Rtx®-CLPesticides and Rtx®-CLPesticides2) joined through a 5 m guard column using a Siltek® “Y” connector.
Oven temperature is programmed from 125 °C to 200 °C at 45 °C/min, then to 230 °C at 12.5 °C/min and finally to 330 °C at 30 °C/min (2 min hold). Helium is used as carrier gas at a constant linear velocity of 41 cm/s. Detection is performed by an Agilent µ-ECD at 330 °C.

Main Results and Discussion

The dual-column approach achieves clear separation of 22 organochlorine compounds, including stereoisomeric pairs (cis/trans-chlordane, BHC isomers) and persistent breakdown products (DDE, DDD, DDT). Peak ordering and retention times confirm excellent resolution and minimal coelution.

Benefits and Practical Applications

• High selectivity and sensitivity for trace-level pesticides.
• Robust dual-column configuration minimizes overlap of critical isomers.
• Applicable to environmental, food safety and quality control laboratories.

Future Trends and Potential Uses

Advances may include coupling with mass spectrometry for enhanced compound identification, accelerated temperature programs for reduced analysis time, and integration into automated workflows for high-throughput monitoring of organochlorines in complex matrices.

Conclusion

The presented GC-ECD method offers reliable, reproducible quantification of a broad suite of organochlorine pesticides with excellent chromatographic resolution, supporting regulatory and research applications.

Instrumentation Used

• GC columns: Rtx®-CLPesticides (30 m × 0.25 mm ID, 0.25 µm) and Rtx®-CLPesticides2 (30 m × 0.25 mm ID, 0.20 µm)
• Guard column: Rxi® guard (5 m × 0.25 mm ID) with Siltek®-treated “Y” connector
• Injection: Cyclo double-taper liner, splitless
• Detector: Agilent µ-ECD at 330 °C
• Carrier gas: Helium

References

• Restek Corporation, Application Notes GC_EV00940 and GC_EV00941