Date of Award

12-1998

Document Type

Thesis

Degree Name

Master of Science (MS)

Department

Environmental Science

First Advisor

Mostafa M Kamal

Second Advisor

Tarek Ghonima

Third Advisor

Dr. Naeem Akhtar Rabi

Abstract

In recent years, the amount of fluoride in biological samples, drinking water and in fluoride containing food or feedstuffs has generated considerable interest. Hence the determination of fluoride is becoming increasingly important due to its implications for environmental health. Fluoride is considered to be amongst the most phytotoxic of the more common pollutants. In response to that extensive research has been made to improve the determination of trace amounts of fluoride through developing different analytical methods. The application of these various analytical methods for fluoride ion determination in water and food samples has gained an enormous interest.

Chapter I of this thesis involves the major aspects of fluoride including availability of fluoride in the environment, physiological effect and mode of action of fluoride. Also it contains a literature survey on the application of various analytical methods of analysis for fluoride ion determination in many of environmental samples.

The experimental part of the thesis is presented in Chapter II. It includes the chemicals, materials and the method of preparation of the various solutions used. The preparation of the different samples for analysis, the methods of analysis as well as the instruments of analysis are described. Moreover, this chapter includes the general standard procedures and techniques established for fluoride ion determination in the environmental samples.

In Chapter III, the results of fluoride ion analysis in the different types of water, tea, honey, juice, dates, spinach and hamour fish were listed. In this context the results indicate that the average value of F- content in the bottled water was 0.103 mg/L which is relatively lower than the corresponding value in well water. The F- was not detected in desalinated water whereas in the holy Zamzam water it is close to 0.4 mg/L. The F- content in tea is 2.33 mg/L and tea could be considered as a good natural source of F-. Also spinach and hamour fish samples could be considered as moderate sources of F-. However, honey, juice and dates contain trace amounts of F-.

Chapter IV describes the application of a spectrophotometric method for the determination of F- in commercial samples. The method depends on the use of Zr (IV)-thiazolyl azo rezorcinol (TAR) system as a spectrophotometric reagent for fluoride ion determination. The results show that the lower detectable concentration of F- using this method was 1x10-5 mol/L of F-. The method was applied for the determination of Fin commercial mouth wash solutions and the results agreed (about 98.3%) of its content shown on the label of the mouth wash solution bottle.

Chapter V summarizes the results of analysis of F- in the various drinking water types and different food samples and recommended the fluoridation of the desalinated water. However, the desalinated water has different uses other than its use as a drinking water, therefore we are recommending the fluoridation of the bottled water.

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