US EPA Method OLM04.2 SVOA (CLP Semivolatiles) by GC-MS on the Supelco SLB™-5ms

Importance of the Topic

Semivolatile organic compounds are common environmental contaminants of concern under EPA’s Superfund program. Reliable, reproducible analysis of these compounds is essential for accurate site assessment, risk management, and regulatory compliance. The use of a validated GC-MS method ensures that laboratories generate data that meet stringent quality requirements in the Contract Laboratory Program.

Objectives and Study Overview

• Demonstrate the separation and detection of an 80-component semivolatile standard plus internal standards.
• Validate US EPA Method OLM04.2 SVOA (CLP Semivolatiles) using a Supelco SLB-5ms GC column.
• Assess chromatographic performance in terms of resolution, peak shape, and method robustness.

Methodology

Sample solutions containing 50 ppm of 80 semivolatile analytes and six internal standards at 40 ppm were prepared in methylene chloride. A single 1 µL pulsed, splitless injection introduced the sample to a GC temperature program starting at 40 °C, ramped to 240 °C at 15 °C/min, then to 330 °C at 10 °C/min. Helium served as the carrier gas at 1.0 mL/min for the first 11 minutes, increasing to 1.5 mL/min for the remainder of the run. MS detection was performed in scan mode over m/z 40–450.

Used Instrumentation

• Agilent 5973 GC-MS system
• Supelco SLB-5ms capillary column, 30 m × 0.25 mm I.D., 0.25 µm film
• 4 mm I.D. single-taper inlet liner
• Helium carrier gas supply

Key Results and Discussion

The optimized conditions achieved baseline separation for all 80 semivolatile analytes, including surrogate and internal standards. Early eluters such as fluorophenols resolved without carryover, while high-boiling compounds like benzo(g,h,i)perylene eluted sharply under the high-temperature hold. Reproducibility tests showed retention time variations within acceptable CLP limits. Scan data provided clear mass spectra for compound identification and quantitation.

Benefits and Practical Applications

The validated GC-MS protocol meets EPA CLP requirements for semivolatile analysis, delivering consistent, high-quality data. Its robustness and reproducibility make it suitable for environmental testing laboratories monitoring soil, water, and waste matrices. The method supports routine QA/QC workflows and facilitates rapid decision-making in contamination assessments.

Future Trends and Applications

Advances in high-resolution mass spectrometry and two-dimensional GC promise even greater selectivity and sensitivity for complex environmental samples. Coupling with automated sample preparation and data processing will further enhance throughput. Emerging applications include non-targeted screening for unknown semivolatiles and miniaturized field-deployable GC-MS platforms.

Conclusion

The US EPA Method OLM04.2 SVOA implemented on a Supelco SLB-5ms column with a 5973 GC-MS analyzer provides reliable separation and detection of a broad range of semivolatile compounds. This protocol ensures compliance with CLP quality standards and supports critical environmental monitoring programs.

References

• Stenerson K. Application Report 478 US EPA Method OLM04.2 SVOA by GC-MS on the Supelco SLB-5ms. Sigma-Aldrich Co. 2008.