News|Articles|June 24, 2025

Measuring PAH Derivatives in Wastewater Using Gas Chromatography

Author(s)Aaron Acevedo

Environmental polycyclic aromatic hydrocarbons can prove dangerous if metabolites enter human systems. A new gas chromatography-based approach was developed to analyze the hydroxy derivatives in wastewater samples.

Key Points

  • Polycyclic aromatic hydrocarbons (PAHs) and metabolites can be excreted into the environment, which can be dangerous to humans.
  • A new method for analyzing PAH hydroxy derivatives (OH-PAHs) in the environment was developed, mainly using gas chromatography-ion trap mass spectrometry (GC-ITQ-MS).
  • The method proved effective in concept and was eventually tested on real wastewater samples.

Researchers from the Cracow University of Technology, Jagiellonian University Medical College, and the AGH University of Krakow investigated new means of analyzing polycyclic aromatic hydrocarbons (PAHs) and hydroxy derivatives (OH-PAHs), in hopes of understanding its impact on aquatic ecosystems. Their findings were published in the Journal of Chromatography A (1).

Polycyclic aromatic hydrocarbons (PAHs) are pollutants that come naturally from coal, crude oil, and gasoline (2). Emissions have been found from sources like incomplete combustion processes, biofuels, and consumer products. Human exposure to PAHs can occur through skin contact, food ingestion, and inhalation, after which these substances are transported to tissues and organs via the bloodstream. While the health effects from PAH exposure is currently unknown, several PAHs and certain PAH mixtures are considered cancer-causing chemicals (2). Further, PAH metabolites in the form of hydroxy derivatives (OH-PAHs) can be excreted from the body, which can potentially be more harmful to living organisms than parent compounds (3). However, there is limited research on OH-PAHs occurrence in the environment, especially its presence in wastewater.

In this study, the researchers aimed to develop and validate a method for determining select OH-PAHs of PAHs in environmental samples. The research focused on using gas chromatography-ion trap mass spectrometry (GC-ITQ-MS), which is a hybrid technique that combines a gas chromatograph’s separation capability with an ion trap mass spectrometer’s analytical capability (4). Specifically, the researchers focused on selecting GC-ITQ-MS operating parameters, optimizing extraction and derivatization to ensure accurate and reliable detection of OH-PAHs in wastewater.

Solid-phase extraction (SPE) using C18 columns eluted with tetrahydrofuran and dichloromethane mixtures provided the best recoveries for a majority of OH-PAHs. Derivatization was optimized by determining the optimal temperature and time conditions, with N-(tert‑Butyldimethylsilyl)-N-methyltrifluoroacetamide (MTBSTFA) being effective for all seven OH-PAHs analyzed within the study. The results confirmed this, with optimized reaction conditions enhancing sensitivity. The method was successfully applied to wastewater samples, specifically to wastewater samples from the Płaszów Wastewater Treatment Plant in Krakow.

OH-PAH presence was detected in concentrations ranging from several to several hundred ng/l. The average concentration values were 75.0 ng/L and 646.8 ng/L for 1- and 2-hydroxynaphthalene, 23.4 ng/L and 543.4 ng/L for 2- and 9-hydroxyfluorene, 13.2 ng/L for 9-hydroxyphenanthrene, and 16.3 ng/L for 1-hydroxypyrene, respectively. Sample analysis was preceded by experiments on OH-PAH stability in wastewater. In contrast, high-performance liquid chromatography–mass spectrometry (HPLC–MS), which is an alternative analysis technique, provides a simplified workflow by eliminating the need for derivatization, in spite of higher detection limits and narrower ranges of detectable OH-PAHs.

GC-ITQ-MS was found to be a robust and sensitive tool for OH-PAH monitoring, which can contribute significantly to environmental analytical chemistry practices. Future research, according to the scientists, could focus on OH-PAHs’ behavior in wastewater treatment processes and in the environment. Overall, this research can provide solid foundations for future OH-PAH studies and its impact on aquatic ecosystems.

References

(1) Pamuła, J.; Sochacka-Tatara, E.; Styszko, K. Development of GC-ITQ-MS Chromatographic System for the Identification of Hydroxy Derivatives of Polycyclic Aromatic Hydrocarbons in Wastewater. J. Chromatogr. A 2025, 1752, 465969. DOI: 10.1016/j.chroma.2025.465969

(2) Polycyclic Aromatic Hydrocarbons (PAHs). CDC 2009. https://www.epa.gov/sites/default/files/2014-03/documents/pahs_factsheet_cdc_2013.pdf (accessed 2025-6-24)

(3) Styszko, K.; Pamuła, J.; Pac, A.; Sochacka-Tatara, E. Biomarkers for Polycyclic Aromatic Hydrocarbons in Human Excreta: Recent Advances in Analytical Techniques—A Review. Environ. Geochem. Health 2023, 45, 7099–7113. DOI: 10.1007/s10653-023-01699-1

(4) 6.2.9 GC/Ion Trap MS. Federal Remediation Technologies Roundtable 2021. https://www.frtr.gov/site/6_2_9.html (accessed 2025-6-24)

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