Detection of Environmental Contaminants Caused by the Oil Spill in the Gulf of Mexico by GC and HPLC

Significance of the Topic

The 2010 Gulf of Mexico oil spill represents the largest accidental marine oil release in US history. Rapid identification and quantification of polycyclic aromatic hydrocarbons (PAHs), petroleum hydrocarbons (PHCs) and volatile organic compounds (VOCs) are essential to assess environmental impact, guide remediation efforts and protect ecosystems and public health.

Study Objectives and Overview

• Develop SPE, GPC, GC-FID, GC/MS and HPLC methods for key hydrocarbon contaminants.
• Compare cleanup strategies including gel permeation chromatography and silica gel SPE fractionation.
• Evaluate advanced stationary phases for improved separation and throughput.

Methodology and Instrumentation Used

Sample preparation combined liquid-liquid extraction with cleanup by GPC using EnviroSep-ABC or fractionation with Strata EPH SPE tubes. Analytical techniques included:

• Gel permeation chromatography on EnviroSep-ABC 350 x 21.2 mm column, UV detection at 254 nm.
• Solid phase extraction with Strata EPH 5 g/20 mL tubes for aromatic and aliphatic fractionation.
• Gas chromatography with flame ionization detection (GC-FID) and mass spectrometry (GC/MS) using Zebron columns: ZB-1 for GRO, ZB-624 for VOCs (purge and trap), ZB-5ms for PAHs and ZB-1XT SimDist for high-boiling fractions.
• High performance liquid chromatography on Kinetex core-shell C18 (100 x 4.6 mm), gradient elution with water and acetonitrile, UV detection at 254 nm.

Main Results and Discussion

Cleanup by gel permeation chromatography and Strata EPH fractionation produced high recoveries and reproducible removal of interferences. Key findings included:

• Aliphatic fraction recoveries for C9–C30 ranged 88–96 with RSD below 3.
• Aromatic fraction recoveries for PAHs ranged 67–97 with tube-to-tube RSD below 3.
• Strata EPH tubes exhibited significantly lower BHT contamination compared to conventional SPE.
• Zebron ZB-1 enabled fast GRO separation in under 14 minutes; ZB-624 with purge and trap GC/MS resolved over 80 VOCs.
• ZB-1XT SimDist characterized hydrocarbons up to C120, addressing high molecular weight crude components.
• ZB-5ms and Kinetex HPLC achieved baseline separation of the 16 priority PAHs in under 6 minutes.

Benefits and Practical Applications of the Methods

• Robust quantification of toxic hydrocarbon fractions to inform risk assessment.
• Fractionation into aromatic and aliphatic portions enables targeted toxicity evaluation.
• Reduced sample preparation interferences and improved throughput for environmental monitoring and regulatory compliance.
• Flexibility to analyze a wide boiling range from volatile C1 compounds to heavy asphaltenes.

Future Trends and Potential Applications

Advances in stationary phase design and sample preparation promise further improvements in speed, sensitivity and selectivity. Emerging trends include the use of core–shell and metal column technologies, automated SPE workflows, miniaturized high-throughput platforms and integration with high-resolution mass spectrometry.

Conclusion

An integrated workflow combining advanced cleanup procedures with modern GC and HPLC columns provides a comprehensive toolkit for monitoring oil spill contaminants. Continued development of specialized materials and instruments will enhance environmental assessments and remediation strategies.

References

1. US Department of Commerce, NOAA Technical Memorandum NMFS-NWFSC-59, Extraction, Cleanup, and Gas Chromatography/Mass Spectrometry Analysis of Sediments and Tissues for Organic Contaminants, March 2004.
2. US Environmental Protection Agency, Quality Assurance Sampling Plan for British Petroleum Oil Spill, May 2010.
3. EPA Method 8015B, Non-Halogenated Organics Using GC/FID, Revision 2, 1996.