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Enhancement on sensitivities and selectivities of absorption and fluorescence spectrometries with combination of various optical effects and application to the natural water analysis.

结合各种光学效应，增强吸收和荧光光谱的灵敏度和选择性，并应用于天然水分析。

基本信息

批准号：
05453068
负责人：
FUJIWARA Kitao
金额：
$ 4.8万
依托单位：
HIROSHIMA UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1993
资助国家：
日本
起止时间：
1993 至 1994
项目状态：
已结题

项目摘要

Various optical effects obtained with lights such as lasers have been used for enhancement in sensitivity and selectivity of absorption and fluorescence spectrometries. First, thermal lensing effect was investigated in the liquid crystal system. It has been discovered, when a dual beam system was employed, the focus of the thermal lens varied according to the orientation of the polarization plane of the probe laser. The thermal lensing signal is twice or larger than that in the isotropic media. Second, when polarized laser light was irradiated into the solution in which diluted magnetic fluid was coexistent with dye, fluorescence of the dye changes under magnetic field. It was found that the magnitude of this change depends on the molecular structure of the dye. These phenomena can be explained by orientation of the dye molecules to the magnetic fluid particles under magnetic field. These results show the oriented media are effective to improve the sensitivity and selectivity of absorption and fluorescence spectrometries. As the application of the optical effects, the photochemical characterization of dissolved organic matter in natural waters was carried out as to the multi-photon ionization. Dissolved organic matter was irradiated by 355 nm output of YAG laser for producing hydrated electrons. Life-time and quenchers of the generated hydrated electron are much different between seawater and land water. Photo-reduction of nitrate to nitrite and chemiluminescence of silane were also investigated for analyzes of nitrate and silicate in seawater.

用激光等光获得的各种光学效应已被用于提高吸收光谱和荧光光谱的灵敏度和选择性。首先，研究了液晶系统中的热透镜效应。研究发现，当采用双光束系统时，热透镜的焦点会随着探测激光偏振面方向的变化而变化。热透镜信号是各向同性介质中的两倍或更大。其次，将偏振光照射到稀释的磁流体与染料共存的溶液中，染料的荧光在磁场作用下发生变化。人们发现，这种变化的大小取决于染料的分子结构。这些现象可以用磁场作用下染料分子对磁流体粒子的取向来解释。结果表明，定向介质可以有效地提高吸收光谱和荧光光谱的灵敏度和选择性。作为光学效应的应用，对天然水体中溶解有机物进行了多光子电离的光化学表征。用输出功率为355nm的YAG激光照射溶解的有机物，产生水合电子。海水和陆地水的水合电子的寿命和猝灭率有很大的不同。还研究了硝酸盐光还原为亚硝酸盐和硅烷的化学发光，用于分析海水中的硝酸盐和硅酸盐。