Development of GC-ITQ-MS chromatographic system for the identification of hydroxy derivatives of polycyclic aromatic hydrocarbons in wastewater

Abstract

The purpose of the study was to develop and validate a method for determining selected hydroxy derivatives of polycyclic aromatic hydrocarbons (OH-PAHs) in environmental samples such as wastewater using gas chromatography-ion trap mass spectrometry (GC-ITQ-MS). This was motivated by the environmental and health risks posed by OH-PAHs, which are widespread pollutants known for their potential carcinogenic and mutagenic properties. The research focused on the selection of GC-ITQ-MS operating parameters, optimizing the extraction and derivatization processes to ensure accurate and reliable detection of these compounds in wastewater. Solid phase extraction using C18 columns eluted with tetrahydrofuran and dichloromethane mixtures provided the best recoveries for most OH-PAHs. The derivatization process was optimized by determining the optimal temperature and time conditions, with the conclusion that MTBSTFA was effective for all seven OH-PAHs analyzed. The developed method was applied to real wastewater samples from the Płaszów Wastewater Treatment Plant in Krakow. The presence of OH-PAH 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. Analyses of real samples were preceded by experiments on the stability of OH-PAHs in wastewater. These studies showed that PAH metabolites change in the aqueous phase, with degradation within a few hours ranging from several to several dozen percent.