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Document Type |
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Thesis |
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Document Title |
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Analysis and Chemical Stability Studies of some Pharmaceutical Compounds in their Formulation Using High Temperature Liquid Chromatography تحليل و دراسة الثبات الكيميائي لبعض المركبات الصيدلانية في صيغتها بإستخدام الكروماتوجرافيا السائلة عند درجات حرارة عالية |
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Subject |
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Chemistry department |
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Document Language |
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Arabic |
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Abstract |
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In this study, a new method was developed for the determination of selected pharmaceutical compounds. The developed method was based on the varying column temperature, flow rates and mobile phase compositions. The stability of Zorbax Eclipse column (XDB-C18) and XBridge C18 was examined at elevated temperatures, using a number of estrogenic and androgenic compounds with different compositions of acetonitrile in water as the mobile phases or with different flow rates. The Eclipse (XDB-C18) column showed a linear van’t Hoff with estrogens and curved with androgens. Also, curved van’t Hoff observed at low percentage of organic modifier used. The XBridge C18 showed non-linear van’t Hoff for all compounds. The curved relationships could be attributed to change in retention mechanism over the temperature range studied. The thermodynamics data of the separations were calculated at each mobile phase. It was shown that the retention of steroids on both columns decreased by raising the temperature.
Moreover, the examined estrogens were removed from solution by the new emerged multi-walled carbon nanotubes. The results showed that the % removed decreased by rising the solution temperature, which indicates the exothermic nature of the process. The effect of different removal time, multi-walled carbon nanotubes (MWCNTs) mass, solution pH, solution temperature, and E1, E2, EE2 concentrations, were studied and optimized for efficient removal. The kinetics of E1, E2, and EE2 adsorption on MWCNTs were analyzed using the different kinetic models and the results showed that the removal was mainly pseudo-second-order process, and the removal efficiency increased at low temperatures. The thermodynamics parameters were calculated and the results showed that the values of the free energies were negative indicating the spontaneity of the removal process. The enthalpy values were negative indicating the exothermic nature of the process, with low values indicating the physical nature of the adsorption.The change in entropy values were negatives indicates the increase in the decrease in degree of disorder as a result of the physical adsorption on the carbon nanotubes surface. |
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Supervisor |
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Dr. Lateefa Al-Khateeb |
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Thesis Type |
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Master Thesis |
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Publishing Year |
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1434 AH
2013 AD |
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Added Date |
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Sunday, January 12, 2014 |
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Researchers
| نجوى علي عسيري | Asiri, Najwa Ali | Researcher | Master | |
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