title: Identification and characterization of phenylacetonitrile as a nitrogenous disinfection byproduct derived from chlorination of phenylalanine in drinking water.
abstract: Unregulated disinfection byproducts (DBPs), including nitrogenous disinfection byproducts (N-DBPs), originating from chlorination of the precursor amino acid phenylalanine in aqueous systems, were identified in laboratory reactions and distributed tap. The major N-DBP identified was phenylacetonitrile, and minor DBPs of benzyl chloride, phenylacetaldehyde, 2-chlorobenzyl cyanide, and 2, 6-diphenylpyridine were also formed. Phenylacetonitrile was generated through decarboxylation, dechlorination and/or hydrolysis processes. With an aromatic structure, phenylacetonitrile has an unpleasant odor of various descriptors and an odor threshold concentration of 0.2 ppt-v as measured through gas chromatography-olfactometry. The half-life of phenylacetonitrile in reagent water and chlorinated water at 19 °C were 121 h and 792 h, respectively. The occurrence of phenylacetonitrile as an N-DBP in tap water was investigated for the first time; the results revealed that μg/L concentrations were present in nine different distributed drinking waters in China and the United States. Phenylacetonitrile deteriorates the aesthetic quality of drinking water and may present risk due to its prolonged existence in drinking water, especially in the presence of residual chlorine.
authors.affiliation: College of Civil Engineering and Architecture, Zhejiang University of Technology, Hangzhou, 310014, China. Electronic address: mayaner@zjut.edu.cn.
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Ma
authors.affiliation: College of Civil Engineering and Architecture, Zhejiang University of Technology, Hangzhou, 310014, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Deng
authors.affiliation: College of Civil Engineering and Architecture, Zhejiang University of Technology, Hangzhou, 310014, China.
authors.forename: Jiao
authors.initials: J
authors.lastname: Feng
authors.affiliation: Department of Chemistry, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA.
authors.forename: Narasimhamurthy
authors.initials: N
authors.lastname: Shanaiah
authors.affiliation: Civil and Environmental Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Smiley
authors.affiliation: Civil and Environmental Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA. Electronic address: andread@vt.edu.
authors.forename: Andrea M
authors.initials: AM
authors.lastname: Dietrich
mesh_terms: D004203:Disinfection; D060766:Drinking Water / Q000737:chemistry*; D054879:Halogenation; D009584:Nitrogen; D010649:Phenylalanine; D014874:Water Pollutants, Chemical / Q000737:chemistry; D018508:Water Purification
chemical_list: D060766:Drinking Water; D014874:Water Pollutants, Chemical; D010649:Phenylalanine; D009584:Nitrogen
keywords: Chlorination; Drinking water; Nitrogenous disinfection byproducts; Odor; Phenylacetonitrile; Phenylalanine