Nontarget Screening of Emerging Contaminants in Jiangsu Section of Yangtze River

With the development of urbanization and industrialization, more and more chemicals were produced in large quantities and widely used. As a result, they entered the water environment through sewage discharge and agricultural drainage. Currently, the analytical methods of contaminants in water include three main strategies, including target screening, suspect analysis and nontarget screening. The number of compounds identified using target screening methods has increased to hundreds, which is far from meeting the current demand for emerging contaminants (ECs) detection in water environment. To comprehensively screen potential emerging contaminants in the Yangtze River in Jiangsu Province, a nontarget screening strategy combined spectral library search with a molecular network was proposed in Jiangsu-Anhui provincial boundary cross section and 22 drinking water sources in Jiangsu section of Yangtze River. Under this strategy, through spectral library screening using a in-ho use library, a total of 118 emerging contaminants were icJeritiHed by accurate mass, isotope dislrihution and MS/MS fragment ions. These contaminants involved pesticides, herbicides, fungicides, drugs, antibiotics, persistent organic pollutants, flame re lard ants, plaslicizers, indicated active agents, chemical inlermediales, and other categories. Since traditional large- led screening relies on commercial standards and screening lists, nonlargel screening is a more favorable approach lo study ECs and lheir transformation products in water. Therefore，unannotaled chemical substances with similar structures lo known conlami- nan is were idenlified through molecular network technology based on the premise thai structurally similar compounds have similar fragment ions. Through using the (xlohal Natural Products Society molecular network ( (tNPS) to extract molecular families， another contaminant with similar toxicity to amantadine ^ N-111 e l h y 1 -1 - a d a ni a 111 a 11 e a ni i 11 e was found. Furthermore，twenty-three contaminants were confh-mecl through commercial standard ^ and 14 of them were delected al a rale of 100%. The quantitative analysis revealed the prevalence of perfluorinatecl compounds，phamiaceuticals，and personal care products in water bodies^ and the total concentrations of the 23 contaminants in each sample ranged from 6. 46 X 102 ng L to 1. 72 X 103 ng, L. Seven drugs and personal care products in water bodies^ and llie total concent rations of the 23 contaminants in each sample ranged from 6. 46 X 102 ng L lo 1. 72 X 103 ng L. Seven drugs and personal care products were de tec led. Amantadine was de tec led a l the highest concent ra I ion among all locations，and p e r fl uo r ooc t a no i c acid (PKOA)，amantadine and 2 , 4-dinitro- phenol were d elected with llie highest mean concentralion levels in each local ion. The nonlargel screening strategy using spectral library search and molecular network enabled high-throughput ideiuification of conlaniinanls in water without prior in forma l ion and standards, in which the structures of unannotaled characteristic peaks were inferred from annoialed substances with spectral libraries. This strategy will accelerate the sys- temalic discovery of emerging and unknown conlaniinanls in llie aqueous environment. © 2023 Chinese Society for Mass Spectrometry. All rights reserved.