Target and Nontarget\nAnalysis of Organophosphorus\nFlame Retardants and Plasticizers in a River Impacted by Industrial\nActivity in Eastern China

Industrial activities are a major source of organophosphorus\nflame\nretardants (OPFRs) and plasticizers in aquatic environments. This\nstudy investigated the distribution of 40 OPFRs in a river impacted\nby major industrial manufacturing plants in Eastern China by target\nanalysis. Nontarget analysis using high-resolution mass spectrometry\nwas further employed to identify novel organophosphorus compounds\n(NOPs). Thirty-four OPFRs were detected in river water samples, with\ntotal concentrations of 62.9–1.06 × 10<sup>3</sup> ng/L\n(median: 455 ng/L). Triphenylphosphine oxide and diphenyl phosphoric\nacid were ubiquitously detected up to 620 and 127 ng/L, respectively.\nAmong 26 identified NOPs, 17 were reported for the first time in the\nenvironment, including 14 novel organophosphate esters (especially\n4 heterocycles and 3 oligomers), 2 organophosphites, and an organophosphonate.\nBis(2,4-di-<i>tert</i>-butylphenyl) hydrogen phosphate and\n2,2-dimethylpropoxy(propyl)phosphinic acid with high predicted persistence\nor toxicity were widely detected, with semiquantified concentrations\nup to 990 and 1.0 × 10<sup>3</sup> ng/L, respectively. Structurally\nsimilar organophosphorus heterocycles exhibited consistent variation\ntrends, suggesting a common emission source. Estimated annual river\ndischarges to the sea were 20.6–37.0 kg/yr for OPFRs and 30.8–161\nkg/yr for NOPs. These findings indicate that industrial activities\ncontribute OPFRs and NOPs to the river catchment and its estuary,\nposing ecological risks to both terrestrial and marine environments.