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

Significance of the Topic

The analysis of semivolatile organic compounds is crucial for environmental monitoring, regulatory compliance, and quality control in industrial and research laboratories. US EPA Method 8270D provides a standardized approach to detect a wide range of pollutants and hazardous compounds in water, soil, and waste samples.

Study Objectives and Overview

This work demonstrates the application of US EPA Method 8270D using a Restek Rxi-5Sil MS column and a drilled Uniliner inlet liner to analyze a comprehensive semivolatile mixture. The objective is to achieve reliable separation and detection of 93 target analytes spanning nitrosamines, phenols, phthalates, polycyclic aromatic hydrocarbons, and other priority pollutants.

Methodology and Instrumentation

The sample, consisting of a US EPA 8270D mix including MegaMix, surrogate mixes, and internal standards, was injected (1 μL) in pulsed splitless mode at 250 °C. The gas chromatograph used helium at a constant flow of 1.0 mL/min. The oven program ramped from 50 °C (0.5 min hold) to 260 °C at 20 °C/min, then to 280 °C at 5 °C/min, and finally to 330 °C at 20 °C/min (1 min hold). Detection was performed by electron ionization mass spectrometry scanning from 35 to 550 amu.

Instrumentation

• Gas chromatograph with Rxi-5Sil MS column (20 m × 0.18 mm ID, 0.18 μm film) and drilled Uniliner inlet liner
• Carrier gas: Helium at 1.0 mL/min
• Injection: 1 μL pulsed splitless (20 psi pulse at 0.2 min, 60 mL/min at 0.15 min)
• Mass spectrometer: Electron ionization source, transfer line at 280 °C, full scan mode (35–550 amu)

Key Results and Discussion

The procedure achieved baseline resolution for all 93 compounds, as evidenced by a clear extracted ion chromatogram at m/z 184. The method provided excellent response for critical analytes such as 2,4-dinitrophenol (relative factor RF = 0.123). Early eluting compounds showed retention times between 7.22 and 7.28 min. Overall, sensitivity and reproducibility metrics met or exceeded EPA performance criteria.

Benefits and Practical Applications

Implementing this method enables laboratories to reliably monitor semivolatile pollutants in environmental matrices and industrial process streams. The optimized column phase and injection technique minimize carryover and maximize analyte recovery. This approach supports regulatory compliance, quality assurance, and contamination screening programs.

Future Trends and Applications

Emerging developments in high-throughput GC-MS platforms, novel stationary phases, and advanced data-processing software will further improve detection limits and analysis speed. Integration with tandem mass spectrometry or QTOF detectors can expand the analyte scope and enhance structural identification. Automation and field-portable GC-MS systems are anticipated to enable rapid on-site assessments.

Conclusion

US EPA Method 8270D implemented on a Restek Rxi-5Sil MS column with a drilled Uniliner inlet provides a robust, reproducible protocol for comprehensive semivolatile organic analysis. The demonstrated performance affirms its value for environmental monitoring and industrial quality control laboratories.

Reference

Restek Corporation Application Note: Semivolatile Organics Analysis using US EPA Method 8270D