20.500.12556/RUL-168743 Insight into photocatalyzed transformations of multiclass organic contaminants in water This study investigates three understudied emerging contaminants: the pharmaceutical ramipril (RAM), the artificial sweetener neotame (NEO), and the herbicide cycloxydim (CYC). Laboratory simulations of natural photoinduced transformations were conducted exploring direct photolysis and TiO$_2$ photocatalysed process, followed by analysis with tandem high-resolution mass spectrometry (HRMS). The contaminants exhibited low-to-medium degree of photolysis, but rapid dissipation under photocatalysis. The assessment of transformation products (TPs) revealed several analytical challenges, particularly in peak detection and data management. The structural elucidation of the abundant TPs was achieved through multi-stage MS fragmentation studies and the transformation pathways were proposed based on the identified structures, evolution profiles, and polarities. The hydroxylation was the most common transformation for all contaminants, although each showed unique additional pathways. For instance, RAM underwent intermolecular cyclization, forming a diketopiperazine-like TP, as well as ketone formation and cleavage into low molecular mass TPs. NEO experienced ester hydrolysis, reduction, resulting in C=C bond formation, and oxidative aromatic ring-opening reactions. Lastly, CYC displayed (poly)hydroxylation or transformations of its oxime ether moiety, which underwent hydrolysis, detachment, or rearrangement, leading to oxazole TPs. The ECOSAR software was used for the prediction of toxicities of the identified TPs. In-silico toxicity prediction showed that the hydroxylated phenolic TPs of NEO and RAM, as well as certain oxazole TP isomers of CYC, have the potential to increase overall toxicity during the degradation. Overall, this paper addresses the analytical challenges and innovative methodologies for studying TPs, highlighting their growing relevance in environmental analytical chemistry. transformation products emerging organic pollutants photocatalysis photolysis high-resolution mass spectrometry non-target analysis identification liquid chromatography Orbitrap transformacijski produkti novodobna organska onesnaževala fotokataliza fotoliza visokoločljivostna mesna spektrometrija netarčna analiza tekočinska kromatografija Orbitrap true false true Angleški jezik Slovenski jezik Članek v reviji 2025-04-22 14:28:24 2025-04-22 14:28:26 2025-04-25 04:11:59 0000-00-00 00:00:00 2025 0 0 13 str. Vol. 1752, art. 465971 2025 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 547.1:544.526.5:543.544.5:543.51 0021-9673 10.1016/j.chroma.2025.465971 233480707 RAZ_Kravos_Aleksander_2025.pdf RAZ_Kravos_Aleksander_2025.pdf 1 ABF366E335034E30E69B2CAFE8F10AC3 9929aa535c06e9386f9b349a973e5646c6668a7cd0d5d755deed74f0845d94f7 44e5d296-20d4-11f0-b232-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=209696 https://www.sciencedirect.com/science/article/pii/S002196732500319X 1 264d8b3d-1f74-11f0-b232-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=209644 Fakulteta za kemijo in kemijsko tehnologijo 0 0 0