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Title:PHOTOLYSIS AND ECOTOXICITY OF THE ANTIBIOTIC CIPROFLOXACIN
Authors:Neparidze, Ketevan (Author)
Pflieger, Marilyne (Mentor) More about this mentor... New window
Files:.pdf RAZ_Neparidze_Ketevan_i2017.pdf (947,78 KB)
 
Language:English
Work type:Bachelor thesis/paper (mb11)
Tipology:2.11 - Undergraduate Thesis
Organization:FZO - Faculty of Environmental Sciences
Abstract:Over the last few decades, numerous pharmaceuticals coming from domestic sewage, livestock, hospitals and industries have been determined in ground, surface and drinking waters. A common example of these pollutants are fluoroquinolones, which are powerful antibiotics used in human and veterinary medicine. The presence of fluoroquinolones in the environment even at low concentration constitutes a threat to ecosystems and human health because they can lead to bacterial resistance issues. Up to now the environmental impacts of fluoroquinolones and their degradation products are not fully understood but it is known that they can negatively affect plants and aquatic organisms. In this study the degradation of ciprofloxacin (CIP) present in synthetic freshwater was investigated under simulated sunlight. Concentrations before and after degradation were determined using HPLC-DAD. The mineralisation rate of the treated solution was monitored on a total organic carbon analyser. The ecotoxicity of the initial samples and the degradation mixtures was assessed on organisms belonging to different trophic levels: a marine bacterium (Vibrio fischeri), a freshwater invertebrate (Daphnia magna) and seed clover (Trifolium repens). In parallel, the EC50 of CIP was determined for all organisms. The Vibrio fischeri and Trifolium repens tests showed that EC50 value was more than 250 mg/L and for Daphnia magna was 190 mg/L. Photolysis of CIP showed that after 90 min of irradiation, CIP was almost totally degraded (99%). Photolysis process of CIP led to the formation of toxic by-products towards Vibrio fischeri. The toxicity test results on Trifolium repens did not show significant difference between the control and the treated plants. Thus, CIP and its degradation products have no effect on the germination or root length of Trifolium repens. Tests on Daphnia magna after 240 min irradiation showed a 94% reduction of the toxic effect. Non-purgeable organic carbon (NPOC) analysis showed that there is no significant mineralisation of the sample even after 240 min of irradiation.
Keywords:Key words: fluoroquinolones, ciprofloxacin, photolysis, toxicity tests, EC50 determination
Year of publishing:2017
Source:Nova Gorica
COBISS_ID:4650747 Link is opened in a new window
URN:URN:SI:UNG:REP:MKFEOIT9
Views:1972
Downloads:154
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Secondary language

Language:Slovenian
Abstract:V Zadnjih nekaj desetletjih so številni farmacevtski izdelki, ki prihajajo iz domačih kanalizacij, živine, bolnišnic in iz industrij, ki so bile določene v talnih, površinskih in pitnih voda. Običajen primer teh onasnaževal so fluorokinolov, kateri so močni antibiotiki, ki se uporabljajo v humani in veterinarski medicini. Prisotnost fluorokinolonov v okolju, tudi pri nizki koncentraciji, predstavlja nevarnost za ekosisteme in tudi za zdravje ljudi, saj lahko privedejo do vprašanja bakterijske odpornosti. Do sedaj so vplivi na okolje fluorokinolonov in njihovi razgradni produkti niso bili povsem razumljivi, vendar je znano, da lahko negativno vplivajo na rastline in vodne organizme. V tej študiji smo raziskali degradacijo ciprofloksacina (CIP), ki je prisoten v sintetični sladki void pod simulirano sončno svetlobo. Koncentracije pred degradacijo in po so bile določene z uporabo HPLC-DAD. Stopnja minerelizacije je bila obdelana z raztopino s katero smo kontrolirali na skupni analizi organskega ogljika. Ekotoksičnost začetnih vzorcev in zmesi razgradnje, je bila ocenjena na organizme, ki pripadajo različnim prehranjevalnm ravnev: morske bakterije (Vibrio fischeri), sladkovodni vretenčar (Daphnia magna) in seme detelje (Trifolium repens). Vporedno s tem je EC50 CIP določil za vse organizme. Preskusi Vibrio fischeri in plazeča detelja, je pokazala, da je bila vrednost EC50 več kot 250 mg/L in za Daphnio magma je 190 mg/L. Fotoliza CIP so pokazale, da je po 90 minutah obsevanja se CIP skoraj popolnoma razgradil (99%). Fotoliza procesa CIP je privedla do nastanka strupenih stranskih proizvodov in sicer v smeri Vibrio fischeri. Rezultati preizkusov toksičnosti na Trifolium repens ni pokazala pomembne razlike med kontrolo in tretiranih rastlin. Tako CIP in njegovi razgradni produkti nimajo vpliva na kalivnost ali na koren dolžine Trifolium repens. Testi na Daphnia magna pa je po 240 minutah obsevanja pokazala 94% zmanjšanja toksičnega učinka. Neodstranjen organski oglijk (NPOC) analiza je pokazala, da ni večjega minerelizacije vzorca tudi po 240 minutah obsevanja.
Keywords:Ključne besede: fluorokinolonov ciprofloksacin, fotoliza, preskusi toksičnosti, EC50 določitve


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