Overview on Polycyclic Aromatic Compounds in Water and Sediment Samples in Vietnam

Abstract

Polycyclic aromatic compounds (PACs), notably unsubstituted and methylated polycyclic aromatic hydrocarbons (PAHs and Me-PAHs), are a group of organic pollutants consisting of two or more fused aromatic rings. They are primarily generated through the incomplete combustion of organic materials and exhibit high toxicity, bioaccumulation potential, and various adverse impacts on ecosystems and human health. The contamination status and distribution characteristics of PAHs and Me-PAHs have been investigated through several case studies in various aquatic ecosystems across Vietnam. However, information about the analytical chemistry and environmental occurrence of PACs in Vietnamese water and sediment samples has not been comprehensively reviewed. Analytical procedures for PAHs in water and sediment typically comprise three main steps: solvent extraction, extract purification, and quantification by gas chromatography-mass spectrometry (GC-MS) or high-performance liquid chromatography with fluorescence detection (HPLC-FLD). PAHs have been frequently detected in Vietnamese water and sediment samples at low to moderate concentration levels. Low-molecular-weight PAHs (LMW-PAHs, 2 to 3 rings) are dominant compounds in water, while high-molecular-weight PAHs (HMW-PAHs, 4 rings or more) tend to accumulate in sediment. Pyrogenic sources are estimated to be more abundant than petrogenic sources. The urbanization process and waste processing activities are major contributors to the emission of PAHs and their derivatives. Additional comprehensive and continuous studies on the analysis and assessment of PACs in Vietnamese aquatic environment are needed.