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中草药太赫兹(THz)谱

Terahertz Time-Domain Spectroscopy of Traditional Chinese Medicines

【作者】 张蕾

【导师】 李福利; 汪力;

【作者基本信息】 首都师范大学 , 物理, 2004, 硕士

【摘要】 太赫兹辐射波段介于红外与微波之间。这是近十几年开发的新的电磁波波段。它有重要的应用前景。国内外对太赫兹辐射的研究很活跃。我们在国际上率先开展了将太赫兹辐射技术用于中医药学研究的探索,并取得了有意义的实验结果。太赫兹辐射通常定义为频率在0.1~10THz(1THz=1012Hz)范围内的相干电磁辐射。在20世纪80年代中期以前,由于缺乏有效的产生和探测方法,人们对该波段电磁辐射性质的了解非常有限。近十几年来,超快激光技术的迅速发展为太赫兹辐射的产生和探测提供了稳定、可靠的激发光源,人们对于太赫兹波段的相关研究越来越多。 太赫兹时域光谱技术是20世纪80年代发展起来的一种新型的光谱测量技术,它使用太赫兹电磁辐射作为探测源,利用电光取样或光电导取样的方法直接记录太赫兹辐射电场的振幅时间波形,通过傅立叶变换得到测量信号振幅和相位的光谱分布,进而获得材料在太赫兹波段的吸收和色散等信息。近年来,太赫兹技术发展的趋势之一是利用太赫兹光谱系统进行生物学方面的研究(包括蛋白质、DNA的太赫兹谱等)。 在中药的光谱研究方面,清华大学用傅立叶变换红外拉曼光谱仪对许多中药进行了系统的研究,出版了专著。这种方法已初步被传统中药学专家所接收。但是,中药学的研究与鉴别是十分困难而紧迫的任务,目前仍需对中药开展多学科综合研究。 将太赫兹辐射用于中药研究,既有特殊的优点也有特殊的困难。1)、中药的大分子的振动或转动谱,有一部分在太赫兹波段。2)、用太赫兹时域光谱技术可以测量中药的色散谱,有可能作为中药鉴别的辅助指标,而红外光谱仪却不能测试色散特性。3)、太赫兹辐射具有相干性,有可能得到与位相有关的信息。4)、太赫兹辐射脉冲宽度在皮秒到飞秒的量级,可以测量中药时域谱和中药瞬态特性。因此,将太赫兹辐射技术用作中药研究与鉴别的补首都师范大学硕士学位论文中草药太赫兹(THz)谱的初步研究充手段是很有希望的。 本论文用太赫兹时域光谱技术研究中药,得到了以下实验结果: 一、用透射型太赫兹时域光谱系统对当归、获荃、积实和板蓝根进行了光谱测量,在T.D.Domey和L.Duvillaret等人提出的理论模型的基础上,通过对这些中药材的太赫兹吸收谱和色散曲线的比较,我们发现,不同种类的中药材由于所含化学成分及其含量的不同,使得相应的太赫兹吸收谱和色散曲线也有着较明显的差异,这种差异主要表现在吸收峰位置的不同、吸收系数的大小以及折射率变化规律的差异中。 二、通过对五个不同厂家生产的银杏叶提取物药物样品和国家药典 (2000版)颁布的标准银杏叶提取物样品的太赫兹吸收谱和色散曲线的比较,我们发现,银杏叶提取物药品与银杏叶提取物标准样品具有不同的THz光谱;不同厂家生产的银杏叶提取物药品的太赫兹吸收谱和色散曲线也不尽相同。这种差异可能来自于添加的辅料不完全相同,或者生产工艺上的不同。 三、通过对特效抗疟药青篙素及其三个衍生物(双氢青篙素、篙甲醚、青篙墟酷)的太赫兹吸收谱和色散曲线的比较,我们发现,青篙素及其衍生物在分子结构上的差异有可能通过太赫兹光谱测量的方法在太赫兹光谱与色散特性中表现出来,这一点证明了太赫兹光谱测量方法对分子的化学结构比较敏感,在鉴别具有较小分子结构差别的同种类药物的不同衍生物方面是有一定的潜力的。 四、借鉴在中红外波段研究中药材光谱特性的样品制备方法和太赫兹波段研究半导体材料、电介质材料、其他生物样品的样品制备方法,对在太赫兹波段研究中药材光谱特性的样品制备进行了探索与实践。通过实践,认为用纯中药材粉末进行压片的样品制备方法是可行的。 五、对中药的太赫兹谱与红外光谱进行了比较研究,测试了银杏叶提取物的红外谱、青篙素及其衍生物的红外谱。比较青篙玻酷的太赫兹吸收首都师范大学硕士学位论文中草药太赫兹(THz)谱的初步研究谱与红外吸收谱,发现两种方式都测到了同一谱线514cm一,。表明本论文所采用的太赫兹时域光谱方法、装置都是可靠的。 本论文得到的以上主要结果未见报导。它为进一步开展中药太赫兹光谱及色散研究并进而建立中药太赫兹谱数据库创造了一定条件。 论文最后对中药太赫兹谱研究中需要进一步研究与改进的问题进行了讨论。

【Abstract】 Terahertz radiation (0.1~10THz) is the gap between microwave and far-infrared region.Before the middle of 1980s,characteristic of THz radiation is rarely known because of lacking effective generation and detection methods. With the development of ultra-fast laser in recent years,stable and reliable methods are available for THz generation and detection. We apply THz techniques in Traditional Chinese Medicine for the first time and obtain some meaningful experimental results.THz time-domain spectroscopy (TTDS) is a powerful tool developed in 1990s for spectroscopy measurement.This technique can record the amplitude of the wave by electro-optical or photoconductive sampling.After fast Fourier transform,the amplitude and phase of the THz pulse wave is given,then the refractive index and absorption of the material in THz region is extracted.Biology is one of the new interests of TTDS in recent years(including study of protein and DNA’s THz spectroscopy).While Fourier Transform Infrared_Raman Spectroscopy is used in Traditional Chinese Medicine’s identification in Tsinghua University, multi-subject research must be developed for the difficult and pressing task.Applied in Traditional Chinese Medicine’s identification,THz radiation has both advantages and difficulties. 1), Some vibrational and rotational modes of Traditional Chinese Medicines’ biomoleculars are in THz region.2, Dispersion spectroscopy of Traditional Chinese Medicine is available in THz region, while not in infrared region.3), Phase information is available as THz radiation is coherent.4), With the pulse width of picosecond and femtosecond,THz radiation can be used to measure the time-domain spectroscopy and transient characteristicof Traditional Chinese Medicines.THz technology is a promising method for Traditional Chinese Medicine’s Identification.In this paper,THz Time-Domain Spectroscopy is used to study Traditional Chinese Medicines.The following is a brief summary of the works conducted in this thesis and the experimental results achieved.1,Jsing the transmission TTDS,we measured and analyzed angelica sinensis (Oliv.) Diels, poria cocos (Schw) Wolf, citrus aurantium L. and isatis indigotica Fort. A model developed by T.D.Dorny and L.Duvillaret et al is used to discuss the principle and method for optical constants extracting.Through the comparison among the four samples’ THz spectroscopy,we find that different medicines have different THz spectroscopy with different peak location,different absorption coefficient and different refractive index.The differences may come from the difference of component and content.2.Through the comparison among the THz spectroscopy of Ginkgo bilaba extract from five different manufacturers and the standard sample of the national pharmacopoeia,we find that medicines and the standard sample have different THz spectroscopy and medicines from different manufacturers have different THz spectroscopy.These differences may come from the difference of assistant materials and manufacturing process.3,Through the comparison among Arteannuin and its three ramifications (Dihydroartemisinin, Artemether and Artesunate)’ THz spectroscopy, we find that the difference of molecular structures of Arteannuin, Dihydroartemisinin,Artemether and Artesunate can be showed in THz spectroscopy.THz spectroscopy is sensitive to the change of molecular structure and has potential in Traditional Chinese Medicine’s Identification.4,The method of making Traditional Chinese Medicines samples in THzregion is discussed in detail.Methods of making samples in mid-infrared region and other samples in THz region are also reviewed.The following experiment results show that pure Traditional Chinese Medicines pellets are fit for THz spectroscopy measurement.5 ,Using IR Spectroscopy, we also measured Ginkgo bilaba extract, Arteannuin and its three ramifications. THz spectroscopy and Infrared spectroscopy of these Traditional Chinese Medicines are compared. The same peak 514cm-1 is detected in both THz spectroscopy and IR spectroscopy of Arte

  • 【分类号】O433.5
  • 【被引频次】9
  • 【下载频次】467
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