الفهرس 
ACKNOWLEDGEMENTSOnly 14 pages are availabe for public view
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Abstract
The eleven sulfonamides (SNs) investigated throughout this work were determined in biodegradation environmental samples. Four of them were determined in photodegradation samples and one in photocatalysis samples.
The thesis consists of five chapters.
Chapter 1
This chapter divided into:
A. Include general introduction about SNs general structure, mode of action, medicinal use and pharmacological effect of the eleven studied SNs, their structures and solubility in different solvents.
B. Include general introduction about the environmental chemistry: some definitions, sources of antibiotics in the environment, occurrence of antibiotics in the environment, effects of the presence of drugs in the environment and on human health, fate of pharmaceutical in the environment, remediation processes, and estimated usage of SNs.
Chapter 2
In this chapter, three simple, efficient, and reliable RP-HPLC methods for the simultaneous determination of eleven SNs have been developed. Analytical separation in two methods was performed with gradient mobile phase system and one method with isocratic mobile phase system. The mobile phase system in the three methods is consisting of 0.1% formic acid in water and acetonitrile. Analytical separation was performed on a RP-C18 column with photodiode-array detection at 270 nm. The column temperature was set at 25 °C with 0.7 mL min-1 flow rate in one of the two gradient methods and 40 °C with 0.5 mL min-1 flow rate in the other gradient one, while at 50 °C with 0.35 mL min-1 flow rate in the isocratic method.
The gradient method 1 was validated in terms of precision, detection and quantitation limits, selectivity, and analytical solution stability according ICH recommendations {International Conference on Harmonization 2005 #154}.
Chapter 3
This chapter divided into:
A. General introduction about photodegradtion. It includes photodegradation definition, types, choice of radiation source, and examples from literature.
B. The photolysis of SNM, SDZ, STZ, and SMP at two concentrations levels (10 and 100 mg L-1) in buffered demineralized water pH 7.4 (BDW) using a medium pressure Hg-lamp was evaluated. Identification of TPs was performed by LC-UV-MS/MS. Information about the degree of mineralization was obtained by DOC calculation using a TOC Analyzer.
The results showed that the four studied SNS were susceptible to UV-photolysis. However, DOC was not completely or not at all removed, thus indicating the formation of TPs. Also kinetic study was performed for the four SNs and it was fitted to pseudo first order kinetic model.
Chapter 4
This chapter divided into:
A. General introduction about photocatalysis. It includes photocatalysis definition, types, mechanism, importance, and examples from literature.
B. The photocatalytic degradation of the antibiotic sulfamethoxypyridazine (SMP) in MP water and STP effluent was examined during the irradiation with a medium pressure Hg-lamp (200 - 600 nm) in the presence of TiO2, FeCl3 and TiO2/ FeCl3 catalysts. The study was carried out by HPLC-UV, and TOC analyzer methods. Identification of the photodegradation TPs was performed by LC-UV-MS/MS using Bruker Daltonic Esquire 6000 plus ion-trap mass spectrometer.
It was found that SMP underwent photocatalytic degradation in the presence of TiO2, FeCl3 and TiO2/ FeCl3, and the optimum catalyst for this process can be FeCl3, due to its high catalytic activity, low cost, non-toxicity and simplicity.
Chapter 5
This chapter divided into:
A. General introduction about biodegradation. It includes biodegradation definition, types, importance, and examples from literature.
B. The biodegradability and the effects on environmental bacteria of eleven SNs and samples from photodegradation tests were studied using the Closed Bottle Test (CBT; OECD 301 D), in which a toxicity control was performed. Also biodegradability of SMP was tested using another test from the OECD series: Manometric Respirometry test (MRT; OECD 301 F). MRT is like CBT but with higher bacterial density and higher test substance concentration.
None of the eleven SNs or the photodegradation TPs was readily biodegradable. The HPLC-UV analysis confirmed that no degradation of any SN was found. However, in photodegradation samples, it was found that one of the TPs showed partial elimination at day 28 which indicate abiotic biodegradation. In the toxicity control, the all substances showed non-toxic effect on environmental bacteria used in the test. from these results, studied SNs and most photo transformation products are assumed to be not readily biodegradable in surface water and therefore are expected to reach or accumulate in the aquatic environment. Thus, the development of bacterial resistance due to the presence of these antibiotics in aquatic environment cannot be ruled out.