Spatial and temporal distribution of N-nitrosamines in tap water using chlorination in Chuncheon, Korea

This study aimed to analyze the spatial and temporal distribution of N-nitrosamines (NAs) in water samples collected from the Soyang Drinking Water Treatment Plant (DWTP) and five tap water sampling locations in Chuncheon, Gangwon State, Republic of Korea, located 0.9 to 6.2 km away from the DWTP. The treated water from the DWTP was monitored for 24 h. NAs were quantitatively measured using high-performance liquid chromatography with fluorescence detection (HPLC-FLD) after solid-phase extraction (SPE) with Carboxen 572, denitrosation, and dansylation. Three NAs in the water samples showed high detection rates exceeding 66.7%, with N-nitrosodimethylamine (NDMA) levels reaching up to 45.0 ng/L in the DWTP and 62.6 ng/L in tap water. The concentration of NDMA increased from 2.50 to 30.7 ng/L in 24 h and showed a significant correlation with dimethylamine, temperature, dissolved organic carbon and nitrogen, and total chlorine. This study highlighted the importance of using advanced monitoring systems for tap water and the necessity of implementing strategies to control NAs.