| Food safety concern and the pesticide residue problem have become serious to us. There are great demands for new technologies that can be applied to pesticide inspection, either to simplify or speed up the detecting process efficiently. In this study THz spectroscopy technique was selected for use. Terahertz (THz) radiation, or THz wave, is a newly developed electromagnetic wave which lies between mid-infrared and microwave radiation. THz wave can be used to characterize the electronic, vibrational and compositional properties of solid, liquid and gas phase materials. As a new tool, THz techniques can obtain more information than traditional methods, which can be used to indentify and detect materials qualitatively and quantitatively.In the thesis the spectroscopy experimental methods and chemometric analytical models was given. The samples contain organophosphorus pesticides, organochlorine pesticides, carbamate pesticides and synthetic pyrethroids. In the research, absorption spectra of different pesticide solutions have been recorded in the infrared and terahertz spectral region. The concentration-dependent absorption spectra across the investigated THz spectral region (0.1-2.5 THz) have been measured by terahertz time-domain spectroscopy (THz-TDS). In spite of no distinct spectral features for solution samples, the absorption spectra are highly sensitive to the overall environment structure and configuration of the samples, as well as their concentration. The results proved that it is possible to determine the residue content in an organic solution. The results from this study showed that THz-TDS spectra combined with multivariate analysis could be used to detect pesticide in food safety. The innovation of this work includes: 1. Instrumentation for THz pesticide detection; 2. Methods for establishing analysis models for THz spectroscopy; 3. Data handling methods for THz spectroscopy; 4. Investigation and proval of THz spectroscopy technique for pesticide detection.
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