title: Iodinated X-ray contrast agents: Photoinduced transformation and monitoring in surface water.
abstract: Conventional wastewater treatment methods have shown to be unsuitable for a complete elimination of iodinated X-ray contrast agents (ICMs), which have thus been found in wastewater treatment plant (WWTP) effluent and in surface water. Once in the surface water, they could be transformed through different processes and form several transformation products that may need to be monitored as well. To this end, we studied the abatement and transformation of ICMs by combining laboratory experiments with in field analyses. We irradiated different aqueous solutions of the selected pollutants in the presence of TiO2as photocatalyst, aimed to promote ICMs degradation and to generate photoinduced transformation products (TPs) similar to those occurring in the environment and effluent wastewater. This experimental strategy has been applied to the study of three ICMs, namely iopromide, iopamidol and diatrizoate. A total of twenty-four, ten, and ten TPs were detected from iopamidol, diatrizoate and iopromide, respectively. The analyses were performed using a liquid chromatography-LTQ-FT-Orbitrap mass spectrometer. The mineralization process and acute toxicity evolution were assessed as well over time and revealed a lack of mineralization for all ICMs and the formation of harmful byproducts. After characterizing these transformation products, WWTP effluent and surface water taken from several branches of the Chicago River were analyzed for ICMs and their TPs. HRMS with MS/MS fragmentation was used as a confirmatory step for proper identification of compounds in water and wastewater samples. All three of ICM were detected in the effluent and surface water samples, while no significant amount of TPs were detected.
authors: Department of Chemistry, University of Torino, via P. Giuria 5, 10125 Torino, Italy.
authors: D
authors: D
authors: Fabbri
authors: Department of Chemistry, University of Torino, via P. Giuria 5, 10125 Torino, Italy. Electronic address: paola.calza@unito.it.
authors: P
authors: P
authors: Calza
authors: Department of Chemistry, University of Torino, via P. Giuria 5, 10125 Torino, Italy; Department of Chemistry, Loyola University, Chicago, IL 60660, United States.
authors: D
authors: D
authors: Dalmasso
authors: Department of Chemistry, Loyola University, Chicago, IL 60660, United States.
authors: P
authors: P
authors: Chiarelli
authors: Department of Molecular Biotechnology and Health Sciences, University of Torino, via P. Giuria 5, 10125 Torino, Italy.
authors: V
authors: V
authors: Santoro
authors: Department of Molecular Biotechnology and Health Sciences, University of Torino, via P. Giuria 5, 10125 Torino, Italy.
authors: C
authors: C
authors: Medana
mesh_terms: D002641:Chicago; D003287:Contrast Media / Q000032:analysis* / Q000737:chemistry; D003973:Diatrizoate / Q000032:analysis / Q000737:chemistry; D004784:Environmental Monitoring; D007472:Iohexol / Q000031:analogs & derivatives / Q000032:analysis / Q000737:chemistry; D007479:Iopamidol / Q000032:analysis / Q000737:chemistry; D010782:Photolysis; D062065:Wastewater / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000737:chemistry
chemical_list: D003287:Contrast Media; D003973:Diatrizoate; D007472:Iohexol; D007479:Iopamidol; D062065:Wastewater; D014874:Water Pollutants, Chemical; C038192:iopromide
keywords: HRMS; TiO(2); X-ray contrast agents; transformation products; wastewater