Naslov
Application of LC-MS to the analysis of photolytic and photocatalytic degradation of febantel

Autori
Čizmić, Mirta ; Babić, Sandra ; Škorić, Irena ; Ljubas, Davor ; Žonja, Božo ; Perez, Sandra ; Ćurković, Lidija ; Petrović, Mira

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
12th Annual LC/MS/MS workshop on environmental applications and food safety / M. Petrović - Barcelona, 2016

Skup
12th ANNUAL LC/MS/MS WORKSHOP ON ENVIRONMENTAL APPLICATIONS AND FOOD SAFETY

Mjesto i datum
Barcelona, Španjolska, 05.07.2016. - 06.07.2016

Vrsta sudjelovanja
Poster

Vrsta recenzije
Nije recenziran

Ključne riječi
liquid chromatography ; mass spectrometry ; photocatalysis ; anthelmintics

Sažetak
Febantel (N-{; ; ; -[2, 3-bis(methoxycarbonyl)- guanido]-5-(phenylthio)-phenyl}; ; ; -2- methoxyacetamide) is an anthelmintic agent active against gastrointestinal parasites in animals. According to its chemical structure it belongs to the group of diphenylsulfide anthelmintic drugs. They are administrated to a wide range of animals in agriculture and aquaculture for treatment against parasites like nematodes and arthropods. Exposure, even to low concentrations of anti-parasitic agents such as anthelmintics in the environment may have negative impacts on terrestrial and aquatic life such as occurrence of resistant strains of parasites. Nevertheless, only a few papers deal with the environmental fate and behavior of the anthelmintic drugs. Because of their wide applicability and possible influence on the living organisms it is of great importance to prevent their entrance into the environment. In recent years, new technologies for the elimination of emerging contaminants such as pharmaceuticals have been studied. Among them advanced oxidation processes (AOPs) are frequently considered to be one of the most promising technologies. AOPs rely mostly on hydroxyl radicals (OH•) as highly reactive, non-selective oxidants that readily oxidize many organic compounds. In most cases, the degradation products are less toxic than the main compound and present less risk to the environment or human health. In this study photolytic and photocatalytic degradation of antihelmintic drug febantel in aqueous media was investigated. Photodegradation experiments were performed using two different UV-radiation lamps: with predominant UV-C (254/185 nm) and with predominant UV-A (365 nm), alone and in combination with TiO2 film as the photocatalyst. The photodegradation followed first-order reaction kinetics in all experiments. Highest degradation rate was achieved with the combination of UV-C radiation and TiO2 film (k=0.3222 min-1), than followed only UV-C radiation (k=0.2593 min-1) and UV- A+TiO2 (k=0.0229 min-1), while with UV-A radiation alone almost no degradation was observed. Degradation of anthelmintic drug febantel was monitored using high performance liquid chromatography coupled to mass spectrometry as an advanced analytical tool. The aim of this study was also to identify degradation products that may occur during advanced oxidation processes. Based on chromatographic analysis and mass spectrometric detection five degradation products were detected during the investigated degradation processes. Tentative structural formulae of degradation products were proposed based on data gathered on mass spectrometer. Also, possible degradation pathways for investigated degradation were proposed. Thus, two main processes can be suggested primary from febantel. These are the oxygenation of one of the phenyl rings of febantel besides methoxyacetamide-substituent-diphenylsulfide- structure bond cleavage to another degradation product with lower mass characteristics. The last proposed path is followed by further cleavage of carbon-sulphur bond in the diphenylsulfide part of the structure, than consequent appearance of the carbamate-side chain into the final degradation molecule. The obtained results revealed that investigated febantel undergo rapid photodegradation under environmentally relevant conditions to the related phenol and carbamate derivatives.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

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