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摘要
At present, the application of infrared spectroscopy in the study of gem identification has been more concentrated in the mid-infrared range of 400 similar to 4 000 cm(-1), and related research on the near -infrared region of the spectrum 4 000 similar to 10 000 cm(-1) has been rarely done. This paperstudied the gemstones, jades and organic gems' NIR spectroscopy by Fourier transform infrared spectrometer. The results showed that gem mineral's NIR widespread presence of water absorption peak, whichwas mainly for different types of water combination tone and overtone, also can appear lower-energy electronic transition absorption peaks. 5 200 cm(-1) +/- was a combination tone of water molecules, and 7 000 cm(-1) +/- was a overtone of =OH while 5 898 and 7 849 cm(-1) +/- centered strong broad absorption band was a lower-energy electronic transition absorption peak. When there was only 7 000 cm(-1) +/- absorption peak, description that water in gem mineral only existed in the form of =OH. When there were 5 200 and 7 000 cm(-1) +/- absorption peaks at the same time, description that water existed in the form of molecules and =OH. The characteristics of organic gems were 5 200 cm(-1) +/- for the combination tone of NH stretching vibration and amide II and 7 000 cm(-1) +/- for the first overtone of NH stretching vibration. The near-infrared spectrum absorption peaks of different varieties of organic gems had different characteristics of position, shape and the relation strength. The characteristics of organic filling gems were 4 061, 4 683 cm(-1) +/- for the combination tone of benzene ring' s =CH stretching vibration and bending vibration and 4 620, 4 683 cm(-1) +/- for the combination tone of =CH stretching vibration and benzene ring skeleton vibration. The absorption peak associated with benzene ring, generally indicates that the sample through the fill process.
- 出版日期2018-1
- 单位昆明理工大学
