Analyze Seven EPA Methods on One GC Column Pair!

Significance of the Topic

Environmental monitoring of halogenated compounds such as pesticides, PCBs, and herbicides relies on robust GC-ECD methods. Running multiple EPA methods on a single column set reduces downtime, cuts costs, and boosts laboratory throughput.

Objectives and Study Overview

This evaluation assessed Restek’s Rtx®-CLPesticides and Rtx®-CLPesticides2 columns in a parallel dual-column GC-ECD configuration for seven EPA methods:

• 8081B: Organochlorine pesticides
• 8082A: PCBs (Aroclors)
• 8151A: Chlorinated herbicides
• 504.1: EDB, DBCP, TCP in drinking water
• 505: Organohalide pesticides
• 508.1: Mixed chlorinated pesticides, herbicides, organohalides
• 552.2: Haloacetic acids and dalapon

Methodology and Instrumentation

A single injector and 5 m guard column feed a “Y” connector to two analytical columns: Rtx®-CLPesticides (30 m × 0.32 mm ID, 0.32 µm film) and Rtx®-CLPesticides2 (30 m × 0.32 mm ID, 0.25 µm film). An Agilent/HP6890 GC with micro-ECD provided simultaneous primary and confirmation data. Helium carrier gas, splitless and pulsed injections, and optimized temperature programs were applied per method.

Main Results and Discussion

• 8081B: Baseline separation of 22 organochlorine pesticides in under 7 min with zero coelutions.
• 8151A: Resolution of 17 chlorinated herbicides in 13 min; confirmational criteria met via elution order shifts.
• 8082A: Clear identification of Aroclor mixtures and key PCB congeners with minimal bleed at high temperature.
• 504.1: EDB, DBCP, and TCP completely resolved from interferences in under 6 min.
• 505: Separation of 16 organohalide pesticide targets in 18 min, meeting inertness and sensitivity requirements.
• 508.1: Analysis of 38 mixed chlorinated analytes in 24 min; all performance criteria (inertness, S/N, resolution) satisfied.
• 552.2: Haloacetic acids and dalapon methyl esters resolved from interferences in under 12 min.

Benefits and Practical Applications

• Reduce method changeover and instrument downtime by using one column pair for seven methods.
• Enhance sample throughput and cost efficiency.
• Maintain consistent chromatographic performance via guard-column protection and single-inlet design.
• Streamline compliance and routine environmental testing workflows.

Future Trends and Opportunities

• Integration of GC-ECD with mass spectrometry for improved selectivity.
• Development of faster, higher-throughput stationary phases.
• Automation of method optimization using AI and data-driven tools.
• Expansion of multi-analyte environmental monitoring platforms.

Conclusion

Restek’s Rtx®-CLPesticides and Rtx®-CLPesticides2 columns enable efficient, multi-method GC-ECD analysis of a broad range of halogenated contaminants on a single setup. High resolution, rapid run times, and reduced maintenance streamline environmental testing and regulatory compliance.