title: Fate and transformation products of amine-terminated PAMAM dendrimers under ozonation and irradiation.
abstract: This article deals with the degradation of a third-generation (G3) poly(amidoamine) (PAMAM) dendrimer under ozonation and irradiation. The identification and quantification of G3 PAMAM dendrimer and its transformation products has been performed by liquid chromatography-electrospray ionization-hybrid quadrupole time-of-flight-mass spectrometry. The dendrimer was completely depleted by ozone in less than 1 min. The effect of ultraviolet irradiation was attributed to hydroxyl-mediated oxidation. The transformation products were attributed to the oxidation of amines, which resulted in highly oxidized structures with abundance of carboxylic acids, which started from the formation of amine oxide and the scission of the CN bond of the amide group. We studied the toxicity of treated mixtures for six different organisms: the acute toxicity for the bacterium Vibrio fischeri and the microcrustacean Daphnia magna, the multigenerational growth inhibition of the alga Pseudokirchneriella subcapitata, and the seed germination phytotoxicity of Licopersicon esculentum, Lactuca sativa and Lolium perenne. Ozonation and irradiation originated transformation products are more toxic than the parent dendrimer. The toxicity of the dendrimer for the green alga was linked to a strong increase of intracellular reactive oxygen species with intense lipid peroxidation.
authors.affiliation: Department of Chemical Engineering, University of Alcalá, 28871 Alcalá de Henares, Madrid, Spain.
authors.forename: Javier
authors.initials: J
authors.lastname: Santiago-Morales
authors.affiliation: Department of Chemical Engineering, University of Alcalá, 28871 Alcalá de Henares, Madrid, Spain; Advanced Study Institute of Madrid, IMDEA Agua, Parque Científico Tecnológico, 28805 Alcalá de Henares, Madrid, Spain. Electronic address: roberto.rosal@uah.es.
authors.forename: Roberto
authors.initials: R
authors.lastname: Rosal
authors.affiliation: Spanish National Institute for Agricultural and Food Research and Technology - INIA, Crta. de la Coruña, km 7.5, 28040 Madrid, Spain.
authors.forename: María D
authors.initials: MD
authors.lastname: Hernando
authors.affiliation: Advanced Study Institute of Madrid, IMDEA Agua, Parque Científico Tecnológico, 28805 Alcalá de Henares, Madrid, Spain.
authors.forename: Maria M
authors.initials: MM
authors.lastname: Ulaszewska
authors.affiliation: Department of Chemical Engineering, University of Alcalá, 28871 Alcalá de Henares, Madrid, Spain; Advanced Study Institute of Madrid, IMDEA Agua, Parque Científico Tecnológico, 28805 Alcalá de Henares, Madrid, Spain.
authors.forename: Eloy
authors.initials: E
authors.lastname: García-Calvo
authors.affiliation: Advanced Study Institute of Madrid, IMDEA Agua, Parque Científico Tecnológico, 28805 Alcalá de Henares, Madrid, Spain; Pesticide Residue Research Group, Department of Hydrogeology and Analytical Chemistry, University of Almería, 04120 Almería, Spain.
authors.forename: Amadeo R
authors.initials: AR
authors.lastname: Fernández-Alba
mesh_terms: D048908:Aliivibrio fischeri / Q000187:drug effects / Q000378:metabolism; D000588:Amines / Q000737:chemistry; D000818:Animals; D000460:Chlorophyta / Q000187:drug effects / Q000254:growth & development; D003621:Daphnia / Q000187:drug effects; D050091:Dendrimers / Q000737:chemistry / Q000528:radiation effects / Q000633:toxicity; D018525:Germination / Q000187:drug effects; D018545:Lactuca / Q000187:drug effects / Q000254:growth & development; D008027:Light; D008129:Lolium / Q000187:drug effects / Q000254:growth & development; D049449:Luminescence; D018551:Solanum lycopersicum / Q000187:drug effects / Q000254:growth & development; D016877:Oxidants / Q000737:chemistry*; D010126:Ozone / Q000737:chemistry*; D012639:Seeds / Q000187:drug effects / Q000254:growth & development
chemical_list: D000588:Amines; D050091:Dendrimers; D016877:Oxidants; C104700:PAMAM Starburst; D010126:Ozone
keywords: Liquid chromatography–electrospray ionization quadrupole/time-of-flight mass spectrometry; Ozonation; PAMAM dendrimer; Transformation products; Ultraviolet irradiation