title: Comparison of gas chromatography-mass spectrometry and gas chromatography-tandem mass spectrometry with electron ionization for determination of N-nitrosamines in environmental water.
abstract: N-nitrosamines are trace organic contaminants of environmental concern when present in groundwater and river water due to their potent carcinogenicity. Therefore, N-nitrosamine analysis is increasingly in demand. Gas chromatography-mass spectrometry (GC-MS) and GC-tandem mass spectrometry (GC-MS/MS), both with electron ionization (EI), were compared for analysis of nine N-nitrosamines extracted from environmental water matrices. A total of 20 fishpond water, river water, and groundwater samples from Sihui and Shunde, China were collected for a survey of N-nitrosamine concentrations in real water samples. Various solid-phase extraction (SPE) conditions and GC conditions were first examined for the pre-concentration and separation steps. The analysis of N-nitrosamines in environmental waters demonstrated that their quantification with GC-MS poses a challenge due to the occurrence of co-eluting interferences. Conversely, the use of GC-MS/MS increased selectivity because of the fragmentation generated from precursor ions in the 'multiple reaction monitoring' (MRM) mode, which is expected to extract target analytes from the environmental water matrix. Thus, the high performance of GC-MS/MS with EI was used to quantify nine N-nitrosamines in environmental waters with detection limits of 1.1-3.1 ng L-1. N-nitrosodimethylamine (NDMA) concentrations were in the range of N.D. to 258 ng L-1. Furthermore, other N-nitrosamines, except N-nitrosomethylethylamine (NMEA), N-nitroso-di-n-propylamine (NDPA) and N-nitrosopiperidine (NPIP), were also detected. Our findings suggest that GC-MS/MS with EI would be widely applicable in identifying N-nitrosamines in environmental waters and can be used for routine monitoring of these chemicals.
authors.affiliation: School of Environmental Studies, China University of Geosciences, Wuhan 430074, China; State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China.
authors.forename: Wenwen
authors.initials: W
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China.
authors.forename: Xiaoshui
authors.initials: X
authors.lastname: Li
authors.affiliation: School of Environmental Studies, China University of Geosciences, Wuhan 430074, China; State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China.
authors.forename: Huanfang
authors.initials: H
authors.lastname: Huang
authors.affiliation: School of the Earth Sciences and Resources, China University of Geosciences, Beijing 100083, China.
authors.forename: Xuetao
authors.initials: X
authors.lastname: Zhu
authors.affiliation: School of Environmental Studies, China University of Geosciences, Wuhan 430074, China.
authors.forename: Xiaoyu
authors.initials: X
authors.lastname: Jiang
authors.affiliation: State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: School of the Earth Sciences and Resources, China University of Geosciences, Beijing 100083, China.
authors.forename: Kuang
authors.initials: K
authors.lastname: Cen
authors.affiliation: School of the Earth Sciences and Resources, China University of Geosciences, Beijing 100083, China.
authors.forename: Lunshan
authors.initials: L
authors.lastname: Zhao
authors.affiliation: School of the Earth Sciences and Resources, China University of Geosciences, Beijing 100083, China.
authors.forename: Xiuli
authors.initials: X
authors.lastname: Liu
authors.affiliation: School of Environmental Studies, China University of Geosciences, Wuhan 430074, China; State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China. Electronic address: shihuaqi@cug.edu.cn.
authors.forename: Shihua
authors.initials: S
authors.lastname: Qi
mesh_terms: D002681:China; D004784:Environmental Monitoring; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D060587:Groundwater / Q000032:analysis; D009602:Nitrosamines / Q000032:analysis*; D061005:Ponds / Q000032:analysis; D045483:Rivers / Q000737:chemistry; D052616:Solid Phase Extraction; D021241:Spectrometry, Mass, Electrospray Ionization; D053719:Tandem Mass Spectrometry; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D009602:Nitrosamines; D014874:Water Pollutants, Chemical
keywords: Electron ionization; Environmental water; GC-MS; GC-MS/MS; Method comparison; N-nitrosamines