Characterization and classification of complex PAH samples using GC-qMS and GC-TOFMS

Area of Science:

• Environmental Chemistry
• Analytical Chemistry
• Mass Spectrometry

Background:

• Polycyclic aromatic hydrocarbons (PAHs) are common environmental contaminants.
• Complex matrices like soil, urban dust, and incinerator ash pose analytical challenges.
• Understanding PAH profiles is crucial for environmental risk assessment.

Purpose of the Study:

• To compare PAH content in diverse complex environmental samples.
• To evaluate the effectiveness of gas chromatography-time of flight mass spectrometry (GC-TOFMS) for detailed PAH profiling.
• To investigate sample classification based on PAH composition.

Main Methods:

• Analysis of polycyclic aromatic hydrocarbons (PAHs) using gas chromatography-quadrupole mass spectrometry (GC-QMS) and GC-TOFMS.
• Principal component analysis (PCA) for sample classification based on PAH profiles.
• Utilizing spectral data to resolve co-eluting peaks and identify compounds.

Main Results:

• GC-TOFMS identified significantly more peaks (962 in pooled, 123-527 in individual samples) compared to routine analysis.
• PCA successfully clustered traffic/incinerator samples and separated PAH-contaminated soils.
• Many samples showed diverse chemical profiles beyond their PAH content, with numerous alkylated PAHs identified.

Conclusions:

• GC-TOFMS offers superior detail for characterizing complex environmental samples and their contamination profiles.
• PCA effectively classifies samples based on PAH composition, aiding in source identification.
• Advanced mass spectrometry techniques provide valuable chemical data for environmental monitoring and toxicological studies.