title: Identifying unknown by-products in drinking water using comprehensive two-dimensional gas chromatography-quadrupole mass spectrometry and in silico toxicity assessment.
abstract: Improvements in extraction and detection technologies have increased our abilities to identify new disinfection by-products (DBPs) over the last 40 years. However, most previous studies combined DBP identification and measurement efforts with toxicology to address concerns on a few expected DBPs, making it difficult to better define the health risk from the individual DBPs. In this study, a nontargeted screening method involving comprehensive two-dimensional gas chromatography-quadrupole mass spectrometry (GC × GC-qMS) combined with OECD QSAR Toolbox Ver. 3.2 was developed for identifying and prioritizing of volatile and semi-volatile DBPs in drinking water. The method was successfully applied to analyze DBPs formed during chlorination, chloramination or ozonation of the raw water. Over 500 compounds were tentatively identified in each sample, showing the superior performance of this analytical technique. A total of 170 volatile and semi-volatile DBPs representing fourteen chemical classes were then identified, according to the criteria that the DBP was presented in the duplicate treated samples. The genotoxicity and carcinogenicity of the DBPs were evaluated using Toolbox, and 58 DBPs were found to be actual or potential genotoxicants. The accuracy of the compound identification was determined by comparing 47 identified compounds with commercially available standards. About 90% (41 of the 47) of the compounds that were automatically identified using the library were correct. The results show that GC×GC-qMS coupled with a quantitative structure-activity relationship model is a powerful and fast nontargeted screening technique for compounds. The method and results provide us a new idea for identification and prioritization of DBPs.
authors: Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China.
authors: Chunmei
authors: C
authors: Li
authors: Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China. Electronic address: dhwang@rcees.ac.cn.
authors: Donghong
authors: D
authors: Wang
authors: Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China.
authors: Na
authors: N
authors: Li
authors: Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China.
authors: Qian
authors: Q
authors: Luo
authors: Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China.
authors: Xiong
authors: X
authors: Xu
authors: State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Science, Chinese Academy of Sciences, Beijing, China. Electronic address: wangzj@rcees.ac.cn.
authors: Zijian
authors: Z
authors: Wang
mesh_terms: D000818:Animals; D002869:Chromosome Aberrations / Q000139:chemically induced*; D004202:Disinfectants / Q000737:chemistry*; D060766:Drinking Water / Q000737:chemistry*; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D054879:Halogenation; D009152:Mutagenicity Tests / Q000379:methods*; D021281:Quantitative Structure-Activity Relationship; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000633:toxicity; D018508:Water Purification / Q000379:methods*; D014881:Water Supply
chemical_list: D004202:Disinfectants; D060766:Drinking Water; D014874:Water Pollutants, Chemical
keywords: Chloramine; Chlorine; Comprehensive two-dimensional gas chromatography–quadrupole mass spectrometry (GC×GC-qMS); Disinfection by-products; Ozone; QSAR Toolbox