Semivolatile Organics US EPA Method 8270 - Rxi®-5Sil MS

Importance of the Topic

Analysis of semivolatile organic compounds (SVOCs) plays a critical role in environmental monitoring, industrial quality control and public health protection. The US EPA Method 8270 is a widely recognized protocol for the identification and quantitation of a broad range of SVOCs, including phenols, nitro-aromatics, phthalates and polycyclic aromatic hydrocarbons (PAHs). By providing reproducible chromatographic separation and mass spectral detection, this method helps laboratories ensure regulatory compliance and assess contamination levels in water, soil and air matrices.

Aims and Overview of the Method

The primary objective of the study is to demonstrate the performance of an Rxi®-5Sil MS capillary column coupled with an Agilent 7890A/5975 GC/MS system for EPA 8270 applications. A standard mixture containing over ninety target SVOCs, surrogates and internal standards was injected to evaluate chromatographic resolution, peak shape and instrument response factors. Emphasis was placed on critical analytes such as 1,4-dioxane, pyridine, nitrobenzene and a suite of PAHs that often challenge laboratory workflows due to their diverse volatilities and polarities.

Methodology and Instrumentation

The separation was performed on a 30 m × 0.25 mm ID, 0.25 µm Rxi®-5Sil MS column. A pulsed splitless injection of 1 µL (10 ng on column) was carried out at 250 °C using a single gooseneck liner with wool. Helium was used as the carrier gas at a constant flow of 1.2 mL/min. The oven temperature program started at 40 °C (1 min hold), ramped to 280 °C at 25 °C/min, then to 320 °C at 5 °C/min (1 min hold). The mass spectrometer operated in full-scan EI mode over 35–550 amu, with the transfer line at 280 °C.

Main Results and Discussion

The system produced a symmetric pyridine peak and excellent resolution of PAH isomers, demonstrating robust chromatographic performance. Response factors confirmed high sensitivity for nitro- and halogenated compounds, with 2,4-dinitrophenol showing a notably high RF of 0.269. Surrogate recoveries and internal standard signals remained within acceptable ranges, underscoring the method’s precision. The comprehensive analyte list—from light volatiles such as 1,4-dioxane and toluene to heavy PAHs like benzo(a)pyrene—was baseline-resolved under the specified conditions.

Benefits and Practical Applications

• Regulatory Compliance: Enables laboratories to meet EPA and international guidelines for SVOC analysis.
• Versatility: Covers a wide polarity and volatility range in a single run.
• Sensitivity: Reliable detection down to low nanogram levels.
• Reproducibility: Consistent retention times and response factors for routine quality control.

Future Trends and Potential Applications

Emerging developments include coupling GC/MS with high-resolution accurate mass (HRAM) detectors for enhanced compound identification. Miniaturized and field-deployable GC systems could facilitate on-site SVOC monitoring. Advances in green sample preparation—solid-phase microextraction and solvent-free techniques—are expected to reduce environmental impact and throughput times. Data processing powered by machine learning may further streamline compound deconvolution and quantitation.

Conclusion

The application of EPA Method 8270 on an Rxi®-5Sil MS column with an Agilent 7890A/5975 GC/MS setup delivers robust, sensitive and reproducible analysis of a diverse SVOC panel. The demonstrated symmetric peaks and high-resolution PAH separations validate the method’s reliability for regulatory and research laboratories.

Reference

US EPA Method 8270: Semivolatile Organic Compounds by GC/MS. Restek Corporation technical data.