title: Sorption and desorption of organic matter on solid-phase extraction media to isolate and identify N-nitrosodimethylamine precursors.
abstract: #x02010;Nitrosodimethylamine is mutagenic in rodents, a drinking water contaminant, and a byproduct of drinking water disinfection by chloramination. Nitrosodimethylamine precursor identification leads to their control and improved understanding of nitrosodimethylamine formation during chloramination. Mass balances on nitrosodimethylamine precursors were evaluated across solid-phase extraction cartridges and in eluates to select the best combination of solid-phase media and eluent that maximized recovery of nitrosodimethylamine precursors into a solvent amenable to time-of-flight mass spectrometry analysis. After reviewing literature and comparing various solid-phase cartridges and eluent combinations, a method was obtained to efficiently recover nitrosodimethylamine precursors. The approach with the greatest recoveries of nitrosodimethylamine precursors involved cation exchange resin loaded with water samples at pH 3 and eluted with 5% NH4 OH in methanol. This indicated that nitrosodimethylamine precursors are amines that protonate at low pH and deprotonate at high pH. Quaternary amines were irreversibly sorbed to the cation exchange cartridge and did not account for a large fraction of precursors. Overall, a median recovery of 82% for nitrosodimethylamine precursors was achieved from 11 surface waters and one wastewater. Applying this method allowed discovery of methadone as a new nitrosodimethylamine precursor in wastewater effluent and drinking water treatment plant intakes.
authors.affiliation: Department of Civil and Environmental Engineering, University of Nevada, Reno, NV, USA.|School of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, AZ, USA.
authors.forename: David
authors.initials: D
authors.lastname: Hanigan
authors.affiliation: Institute of Municipal and Environmental Engineering, College of Civil Engineering, Huaqiao University, Xiamen, Fujian, P.R. China.
authors.forename: Xiaobin
authors.initials: X
authors.lastname: Liao
authors.affiliation: School of Molecular Sciences, Arizona State University, Tempe, AZ, USA.
authors.forename: Jinwei
authors.initials: J
authors.lastname: Zhang
authors.affiliation: School of Molecular Sciences, Arizona State University, Tempe, AZ, USA.
authors.forename: Pierre
authors.initials: P
authors.lastname: Herckes
authors.affiliation: School of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, AZ, USA.
authors.forename: Paul
authors.initials: P
authors.lastname: Westerhoff
mesh_terms: D000327:Adsorption; D004128:Dimethylnitrosamine / Q000032:analysis*; D015394:Molecular Structure; D052616:Solid Phase Extraction; D013499:Surface Properties
chemical_list: D004128:Dimethylnitrosamine
keywords: Disinfection byproducts; Fractionation; Isolation; N-Nitrosodimethylamine; Precursors