title: Quantification of Total N-Nitrosamine Concentrations in Aqueous Samples via UV-Photolysis and Chemiluminescence Detection of Nitric Oxide.
abstract: N-Nitrosamines are potent mutagens and carcinogens that can be formed during oxidative water treatment. This study describes a novel method for the determination of total N-nitrosamines by UV-photolysis and subsequent chemiluminescence detection of nitric oxide. Denitrosation of N-nitrosamines was accomplished with a microphotochemical reactor consisting of a knitted reaction coil and a low-pressure mercury lamp. The detection limits for differing N-nitrosamines ranged between 0.07 μM (14 pmol injected) and 0.13 μM (26 pmol injected). The nitric oxide formation from selected N-nitrosamines was linear (R2= 0.98-0.99) from 0.1 to 10 μM. The small cross-section and volume of the microphotochemical reactor used in this study was optimal to reach a sensitivity level comparable to chemical denitrosation-based methods. In addition, this method had several advantages over other similar methods: (i) compared to chemical denitrosation with copper monochloride or triiodide, the UV-photolysis does not require chemicals and is not affected by interferences of byproducts (e.g., formation of NOI), (ii) the reproducibility of replicates was enhanced compared to the triiodide-based method, and (iii) a commercially available photoreactor and NO analyzer were used. The application of this method for the determination of the N-nitrosamine formation potential of personal care products demonstrates its utility for assessing whether N-nitrosodimethylamine (NDMA) or other specific nitrosamines of current interest are dominant or minor components, respectively, of the total N-nitrosamine pool in technical aquatic systems or biological samples.
authors.affiliation: School of Architecture, Civil and Environmental Engineering (ENAC), Ecole Polytechnique Fédérale de Lausanne (EPFL) , CH-1015 Lausanne, Switzerland.
authors.forename: Florian
authors.identifier: 0000-0002-5698-0314
authors.initials: F
authors.lastname: Breider
authors.affiliation: School of Architecture, Civil and Environmental Engineering (ENAC), Ecole Polytechnique Fédérale de Lausanne (EPFL) , CH-1015 Lausanne, Switzerland.|Eawag, Swiss Federal Institute of Aquatic Science and Technology , CH-8600 Dübendorf, Switzerland.
authors.forename: Urs
authors.initials: U
authors.lastname: von Gunten
mesh_terms: D003358:Cosmetics / Q000032:analysis; D006801:Humans; D057230:Limit of Detection; D008163:Luminescent Measurements / Q000295:instrumentation / Q000379:methods*; D009569:Nitric Oxide / Q000032:analysis*; D009602:Nitrosamines / Q000032:analysis*; D010782:Photolysis / Q000528:radiation effects; D015203:Reproducibility of Results; D014466:Ultraviolet Rays; D014867:Water / Q000737:chemistry*
chemical_list: D003358:Cosmetics; D009602:Nitrosamines; D014867:Water; D009569:Nitric Oxide