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

Significance of the Topic

Environmental contamination from large oil spills poses serious risks to ecosystems and human health. Rapid and reliable analytical workflows are crucial for characterizing key pollutant classes such as polycyclic aromatic hydrocarbons (PAHs), petroleum hydrocarbons (PHCs), and volatile organic compounds (VOCs). This study addresses the need for robust sample cleanup, fractionation, and high-throughput detection methods following the 2010 Gulf of Mexico spill.

Study Objectives and Overview

The work aims to develop and validate complementary analytical protocols to detect and quantify major oil-related contaminants. Key goals include

• Optimizing sample cleanup strategies to remove matrix interferences
• Fractionating complex petroleum mixtures into aliphatic and aromatic components
• Applying chromatographic techniques—GC-FID, GC/MS, and HPLC—for targeted analysis of PHCs, PAHs, and VOCs
• Demonstrating improved speed, reproducibility, and sensitivity using advanced stationary phases

Methodology and Instrumentation Used

Sample preparation combined gel permeation chromatography (GPC) and solid-phase extraction (SPE) cleanup steps:

• GPC cleanup on EnviroSep™-ABC columns to remove high molecular weight impurities in accordance with NOAA TM NMFS-NWFSC-59
• Silica gel SPE fractionation using Strata® EPH cartridges to separate aliphatic and aromatic hydrocarbon fractions

Analytical determinations employed:

• GC-FID for total petroleum hydrocarbon (TPH) profiling and fraction analysis
• GC/MS for semi-volatile PAHs and VOC speciation
• Purge-and-trap GC/MS using Zebron™ ZB-624 columns for rapid VOC screening
• Fast GC of the gasoline-range organics (GRO) on Zebron™ ZB-1 columns
• Comprehensive simulated distillation on Zebron™ ZB-1XT SimDist metal columns for heavy hydrocarbon characterization
• HPLC with Kinetex® core-shell C18 columns for sub-6-minute separation of the 16 priority PAHs

Results and Discussion

Cleanup and fractionation

• GPC on EnviroSep™-ABC provided a defined elution window maximizing separation of toxic PAHs (e.g., dibromooctafluorobiphenyl and perylene)
• Strata EPH SPE yielded high recoveries for C9–C30 aliphatic hydrocarbons (88–96%, RSD <3%) and PAH recoveries of ~67–97% (RSD <3%)
• Low tube-to-tube contamination and consistent flow improved reproducibility compared to conventional SPE

GC and GC/MS analysis

• Fast GRO separation on Zebron ZB-1 resolved key components (benzene, toluene, xylenes, naphthalene) in ~14 minutes
• Purge-and-trap GC/MS on ZB-624 achieved baseline separation of 82 VOCs, covering chlorinated, halogenated, and aromatic species
• SimDist on ZB-1XT metal columns characterized crude oil up to C120+ in a single run to 450 °C
• Zebron ZB-5ms GC/MS provided rapid isomer resolution for the EPA 16 PAH mix in ~12 minutes

HPLC analysis

• Kinetex core-shell C18 enabled all 16 priority PAHs to elute within 6 minutes using a water–acetonitrile gradient, improving throughput on standard HPLC systems

Benefits and Practical Applications

The integrated workflows deliver:

• High-throughput screening for regulatory monitoring (EPA Methods 8015B, 8270, 8310)
• Enhanced sample fractionation for precise toxicity assessments
• Improved reproducibility and reduced matrix interferences
• Broad applicability across environmental matrices: water, sediment, tissue, and crude oil

Future Trends and Potential Applications

Ongoing developments may include:

• Advanced sorbent chemistries for emerging oil spill dispersants and additives
• Miniaturized and field-deployable SPE and GPC devices for in-situ screening
• Ultrafast two-dimensional GC and UHPLC–MS techniques for even greater resolution
• Machine learning–driven data processing to automate identification and quantitation

Conclusion

This work demonstrates a suite of complementary cleanup and analytical solutions for comprehensive assessment of oil spill contaminants. By combining GPC, SPE fractionation, advanced GC columns, and core-shell HPLC particles, laboratories can achieve rapid, reproducible, and sensitive detection of PHCs, PAHs, and VOCs critical for environmental monitoring and risk assessment.

References

1. NOAA Technical Memorandum NMFS-NWFSC-59, "Extraction, Cleanup, and Gas Chromatography/Mass Spectrometry Analysis of Sediments and Tissues for Organic Contaminants," U.S. Department of Commerce, 2004.
2. EPA Method 8015B, Non-Halogenated Organics by GC/FID, Revision 2, U.S. Environmental Protection Agency, 1996.
3. EPA Method 8270, Semivolatile Organic Compounds by GC/MS, U.S. Environmental Protection Agency.