Terahertz Study On Metal Gluconates And Water-1,4-dioxane System

The resonance absorptions of molecules in the terahertz?THz? region always originate in weak interactions, such as hydrogen bonding and van der Waals force, which play important roles in the molecular network structures and molecular interactions. THz wave is so sensitive to those weak interactions that it can distinguish drug polymorphs, isomeride and chemical analogs. In addition, THz wave can penetrate common packaging materials. Therefore, THz technology has been widely used in food process monitoring and quality control and pharmaceutical analysis.Water is indispensible and is a good solvent that is capable of dissolving a variety of different substances. Lots of chemical reactions and live processes proceed in water. Understanding the mechanism behind water and solute interaction is vital to daily life and expands human's knowledge of nature. Water is very sensitive to terahertz?THz? wave and has a strong absorption in THz band. Based on this characteristic, many researches on the mechanism and principles of the interaction between water and solute have been carried out and laid the fundation for THz applications in the biomedical field. This thesis presents three main parts:1. The method for extraction of material parameters in THz-TDS was presented. A graphical user interface?GUI? based on Matlab was built to make dielectric parameters calculation and results saving more convenient.2. THz characteristic absorption of metal gluconates(Na⁺, K⁺, Mg²⁺, Ca²⁺, Fe²⁺, Cu²⁺, and Zn²⁺) were obtained by THz-TDS. Binary and ternary mixtures of different gluconates were quantitatively analyzed based on the Lambert-Beer law. A chemical map of a tablet containing Calcium D-gluconate monohydrate and ?-lactose in the polyethylene host was obtained by THz imaging. The study shows that THz technology is a useful tool in pharmaceutical research and quality control applications.3. Water-1,4-dioxane system was investigated by THz-TDS at different concentration and different temperature in 0.2-1.5 THz. Deviation between the experimental results and ideal results in terahertz absorption was observed and discussed. The number of water molecules in the hydration shell was calculated. The results help to illustrate the microscopic behavior of water and 1,4-dioxane.