Improved Analysis of EPA Method 8270D on a Zebron™ ZB-SemiVolatiles Column

Importance of the Topic

The analysis of semivolatile organic compounds by EPA Method 8270D is essential for environmental monitoring and contamination assessment. However, the method’s extensive analyte list and the reactivity of many target compounds often result in lengthy run times and challenging chromatographic separations. An optimized approach that reduces analysis time while maintaining resolution and peak integrity is crucial for high-throughput laboratories and accurate quantitation.

Objectives and Study Overview

This study demonstrates an improved protocol for EPA Method 8270D using the Zebron ZB-SemiVolatiles gas chromatography column. The primary goals were to shorten run times, enhance peak shape for acidic and basic analytes, and achieve baseline separation of critical isomer pairs to streamline semivolatile compound analysis.

Methodology and Instrumentation

Instrumentation and conditions:

• Gas chromatograph: Agilent 6890
• Mass spectrometer: Agilent 5973 MSD
• Column: Zebron ZB-SemiVolatiles, 30 m × 0.25 mm × 0.25 µm
• Injection: 1 µL split 10:1 at 280 °C
• Carrier gas: Helium at 1.4 mL/min (constant flow)
• Oven program: 40 °C (0.5 min) → 260 °C @ 40 °C/min → 295 °C @ 6 °C/min → 325 °C @ 25 °C/min (2 min)

Main Results and Discussion

• Run time was reduced to 16 minutes for 137 analytes, compared to over 20–35 minutes on conventional methods.
• Acidic phenols displayed excellent peak shapes (e.g., 2,4-dinitrophenol skew=1.04; pentachlorophenol skew=1.15), and reactive amines such as pyridine showed minimal tailing (tailing factor=1.49).
• Baseline separation achieved for critical pairs sharing masses: aniline/bis(2-chloroethyl)ether (m/z 93), 2,4,5- and 2,4,6-trichlorophenol (m/z 196).
• High resolution for PAH isomers: benzo[b]/benzo[k]fluoranthene (resolution 9.9%) and indeno[1,2,3-cd]pyrene/dibenz[a,h]anthracene (resolution 20.9%), well below the 50% requirement.
• Small split injection allowed separation of solvent (dichloromethane) from early eluting compounds such as 1,4-dioxane.
• Superior deactivation extended calibration stability and column lifetime by minimizing analyte degradation and need for maintenance.

Benefits and Practical Applications

• Increased sample throughput enhances laboratory productivity and revenue potential.
• Improved quantitation accuracy for reactive and thermally labile compounds.
• Reduced downtime and maintenance thanks to extended column lifetime.
• Consistent calibration performance across diverse sample matrices.

Future Trends and Opportunities

• Further tuning of temperature programs for emerging semivolatile contaminants.
• Integration with advanced tandem MS detectors for greater selectivity in complex matrices.
• Expansion of inert stationary phases tailored to additional reactive compound classes.
• Automated split injection methods to improve sensitivity and minimize solvent interference.

Conclusion

The Zebron ZB-SemiVolatiles column provides a robust solution for EPA Method 8270D by combining high inertness, efficiency, and chromatographic resolution. Laboratories can achieve faster run times, exceptional peak shapes for challenging analytes, and extended column lifetimes, thereby improving throughput and data quality in semivolatile compound analysis.

References

1. EPA Method 8270D: Semivolatile Organic Compounds by Gas Chromatography/Mass Spectrometry (GC/MS), Revision 4, February 2007.
2. Phoenix Environmental Laboratories, Inc., Customer Testimonial on ZB-SemiVolatiles column performance.
3. McKernan R., TestAmerica Laboratories, Inc., Buffalo, Customer Testimonial on column durability and reproducibility.