Terahertz Spectroscopic Investigation Of Illicit Drugs And Sedative Drugs

Terahertz (THz) radiation,which lies between infrared and microwave in the electromagnetic spectrum, belongs to far-infrared band. Usually studied THz radiation is the electromagnetic wave in the range of 0.1THz ~ 10THz (30μm ~ 3mm or 33cm-1 ~ 330cm-1). The mushroom of THz technology provides a new approach of inspection for illicit drugs and medicine. In this paper, we employ the method of combining THz spectroscopy and infrared technology to study some of common amphetamine-type smuggling drugs and a series of sedative drugs which have the active ingredients belong to the scope of illicit drugs. We mainly studied them in the aspects of spectral experiments, theoretical analysis and its applications. The work of this thesis contains four parts.Firstly, several common amphetamine-type smuggling drugs are studied using both the terahertz time-domain spectroscopy (THz-TDS) and the new-type equipment of VERTEX 80v vacuum Fourier transform infrared spectroscopy (FTIR). And we compared the similarities and differences of the two ways of far-infrared inspection technology.Secondly, we employ the effective medium theory to extract some optical constants of the pure MA from the mixtures of different ratio of flour-doped"Ice Drugs". The extracted optical constants contain the absorption coefficient of pure MA that is more meaningful for the practical application. The results of theoretical calculations agree well with the actual measured experimental results.Thirdly, the THz-TDS technology and traditional FTIR technology are combined to experimentally study the mid-infrared and THz spectroscopy of different types of sedative-hypnotics. Their spectral characteristics are compared and analyzed. In addition, on the basis of experiments, we made some molecular dynamics simulations for a series of benzodiazepine sedative-hypnotics. Theoretical results all agree well with experimental ones. Then, attribution analysis is given for their main absorption peaks of THz spectroscopy and infrared spectroscopy. Finally, the THz-TDS technique is employed to do the comparative study for the actual sedative drugs from different drug-manufacturers. It is a preliminary attempt to using the THz-TDS technology to inspect the quality of sedative drugs and to identify their manufactures.