【作者】 张文艳；

【导师】 陈亚光；

【作者基本信息】 中南民族大学 ， 生物医学工程， 2008， 硕士

【摘要】 激光诱导击穿光谱(Laser-Induced Breakdown Spectroscopy,简称LIBS)是一种新的多元素同时检测方法,其工作原理是利用高能脉冲激光束聚焦后入射到样品表面,产生激光等离子体,通过分析等离子体的光谱进行物质元素的定性分析和定量测量。目前临床上体液中各种成分的检测多数采用化学的方法,这些方法一般都需要对样品进行预处理,且不能多元素同时检测,对体液中微量元素的检测更是难以实现。因此本论文提出采用LIBS技术来检测体液成分。本论文以探索LIBS技术用于人体体液监测的可行性为目的,对模拟体液的激光诱导击穿光谱特性进行了系统的实验研究。本论文采用Nd:YAG脉冲激光器、echelle光谱仪、ICCD等仪器搭建了液体LIBS实验装置。并在此装置上分别针对各种实验参数展开了提高LIBS综合检测能力的实验研究,归纳出较为理想实验参数,激光器的工作频率为10Hz、采集次数为20次,透镜到样品表面的距离小于透镜焦距(具体值根据实验条件决定)。利用液体LIBS的实验系统,对模拟体液进行了定性分析和定量分析。通过对模拟体液全谱的测量,结果发现,可以同时探测到多种元素成分,且LIBS方法对金属元素比非金属更敏感,检测限更高。分别对纯有机物(葡萄糖)溶液和多种无机物溶液开展了LIBS探测的初步实验研究,在大量系列实验的基础上,总结出了各元素的特征谱线。为了进一步定量检测模拟体液各元素成分的含量,还开展了特征谱线的强度和各元素含量关系的研究,建立了部分元素的定标曲线,发现不同元素由于其本身特性不同,其定标曲线也不一样。实验表明:Na、Pb元素的定标曲线满足罗马金-赛伯公式,而As元素的定标曲线却满足多项式方法原理。总之,利用LIBS技术同时、快速、精确地检测出模拟体液中多种元素的含量的设想是完全可行的,并且现有的研究结果将为进一步开展LIBS体液研究提供技术支持和实验依据。更多还原

【Abstract】 Laser-induced breakdown spectroscopy (LIBS) has been widely utilized as a multi-elemental analysis method. In LIBS, a high-power pulsed laser beam is focused onto the surface of a sample, ablating a small quantity of it. The ablated material is vaporized and then partially atomized, excited and ionized, producing a plasma plume above the surface. The emission spectrum from the plasma plume can be spectrally and temporally resolved and used for identification and quantification of the elements present in the plume. Chemic methods are used for recent clinical research on the detection of body fliud, which need sample treatment, and can’t detect multi-elements simultaneously and trace elements. So we brought forward an assumption that LIBS was applied to analyze body fluid. Experiments were conducted in order to demonstrate the the feasibility of detecting body fluid using LIBS.Liquid experimental setup for LIBS system was established by a Nd:YAG laser、a echelle spectrometer、an intensified charged couple device (ICCD) detector, and a computer for control and data acquisition. In order to achieve higher sensitivity and more delicate analysis with LIBS, the experimental parameters including laser parameters、ICCD setup and lens-to-sample distance(LTSD) should be appropriately selected. In this paper, most spectra were acquired by accumulation of twenty single shots, ten hertz of laser work frequency, LTSD less than lens’s focus length.The qualitative and quantitative analyses of simulate body fluid were performed with LIBS. The qualitative results showed that LIBS method could detect multi-element simultaneously and detection limit of metal was higher than nonmetal. The experiments of organic and inorganic solution were carried on, respectively. Via a series of experiments data, characteristic spectra of different elements were analyzed and calibration curves of portion elements were recorded. Further more, it was demonstrated that the calibration curves of Na and Pb were consistent with Lomakin-Scheibe formula, but As disagreed.In a word, the detection assume of simulate body fluid using LIBS was validated. And all the existing results could provide technique-abet and experimental gist for the further investigation of body fluid with LIBS.更多还原