The author wishes to express his sincere gratitude to the Chief chemist, Government chemist and the chief engineer, engineer Maina, ministry of public works, and materials branch for support during the entire research period when there was inadequate funding. The good co-operation of the deputy government chemist, Mrs. Okado and the Head of Departments in both foods and water and the whole government chemist staff is highly acknowledged. Special thanks go to Professor Jane Murungi and Dr. Charles Onindo of Kenyatta University for their supervision of the thesis and helpful critical comments that resulted in the presentation of the data obtained. Thank you also for your gifted editing, your hard work and your patience. The author greatly appreciate the typing assistance of my loving wife Mrs. Rosalia Masime. Lastly, thanks to the Teachers Service Commission for granting me study leave with pay, my lecturers, Dr. Ruth Wanjau, Professor Gerald Muthakia, Dean (SPAS), Dr. Richard Musau, (Chairman, Chemistry Department), Prof. Hudson Nyambaka and Dr. Koga (Academic registrar) all of Kenyatta University, for their support.