Formation of N-nitrosodimethylamine by chloramination of anthropogenic nitrogenous compounds with dimethylamine monitored by Japanese water authorities

Water Analysis: Emerging Contaminants and Current Issues

“…A study in Japan by Hinneth et al used the Japanese Pollutant Release and Transfer Registers (PRTRs) to investigate potential dimethylamine-containing compounds that might form NDMA. 186 In all, 31 compounds were identified and were reacted with monochloramine in pure and natural river waters containing NOM. Highest NDMA levels formed from compounds with tertiary amines and aryl groups in a β-position to the nitrogen in the dimethylamine group.…”

Predictable Liquid Chromatography Quadrupole Time-of-Flight Mass Spectrometry Fragmentation of Ozone-Reactive N-Nitrosodimethylamine Precursors Coupled with In Silico Fragmentation and Ion Mobility-Quadrupole Time-of-Flight Facilitates Their Identification in Sewage

“…These results confirmed our assumptions that O 3 -reactive precursors have predictable fragments that are different from the NH 2 Cl-reactive precursors. 7,21 Table 1B shows the results of the mixture sample (1 mg/L; MQW) of known NH 2 Cl-and O 3 -reactive NDMA precursors. We tested the fragments to flag the precursors, assuming no prior knowledge of their identity.…”

“…Finally, we fractionated the pretreated samples with high O 3 -reactive precursors by HPLC (using a Zorbax SB-Aq column: 4.6 × 150 mm; Agilent Technologies) to purify and increase the precision for identification. The chloramination and ozonation conditions, including NDMA extraction and measurement, are adapted from the studies of Hinneh et al 7 and Kosaka et al, 5,30 with a few notable modifications annotated in Figure S4 and Sections S8 and S10−S13. Application of Discovered Fragmentation Patterns on Sewage.…”

“…Carcinogenic N- nitrosodimethylamine (NDMA), a frequently detected N -nitrosamine in finished drinking water, − is a disinfection byproduct of chloramination and ozonation of waters impacted by treated sewage containing organic compounds bearing N,N -dimethylamine (DMA) or N,N -dimethylhydrazine (DMH). − NDMA is on the fourth contaminant candidate list (CCL 4) by the United States Environmental Protection Agency (US EPA) and is on a list for further study for drinking water regulation in Japan. , To protect public health, NDMA must be removed or avoided well below its guidance value (3–100 ng/L). − Unfortunately, current conventional and advanced water treatments have some limitations in abating NDMA formation. − This warrants robust source control strategies to eliminate NDMA precursors during water treatment.…”

“…Source control strategies rely on studies that identify potent NDMA precursors by target analysis. ,,, However, this approach is somewhat limited because of the insufficient proof of occurrence of identified precursors to account for NDMA formed in treated waters . Instead of target analysis, studies − have used fragmentation data of known compounds to estimate chemical structures of unknown compounds, and only one study has used fragmentation data of NDMA precursors to aid their identification in environmental waters.…”