STABLE ISOTOPES AS BIOTRACER BY NOVEL LASER METHODS

拟议的研究涉及小说的设计和应用， 超灵敏、高分辨率激光光谱分析方法 矿物生物化学--重要元素的测量。为 膳食可利用性和矿物质吸收研究，使用 稳定同位素提供了一种有吸引力的替代方案 放射性同位素由于安全和伦理方面的原因。虽然 稳定的同位素已经被频繁地使用，目前可用的 稳定同位素测定方法严重限制了 生物示踪剂研究中稳定同位素的使用。即使是最常见的 使用的方法，质谱学有许多缺点，包括 样品处理速度慢、化学干扰和要求 耗时的样品纯化和络合步骤。 在这个提案中，创新的、强大的、基于激光的方法- 光学位相共轭光谱与偏振 光谱学-是为了克服许多困难而提出的。 这些无多普勒(和无洛伦兹)激光光谱 方法产生的光谱分辨率足够高，足以分辨 原子/同位素超精细结构--光谱 原子的指纹。因此，优秀的元素/同位素 获得了选择性，光谱和化学干扰 即使样品中含有一定数量的 矿物。除了选择性之外，这些非线性激光器 方法还提供了最灵敏的检测极限之一， 因此，它们具有进行痕量同位素分析的潜力。 浓度(ppm和pptr)或简单定量 生物样品中矿物质的测量。这些非线性 激光方法使用多个输入激光束来诱导非线性 并在样品中产生信号波束。立方信号 光学相位共轭光谱中激光功率的依赖关系 (以及偏振光谱中的二次依赖)允许 极其有效地利用激光提供的高光子能量。 由于信号是一束激光，所以光学检测非常有效。 虽然分析火焰可以用作雾化器以提供快速， 方便、连续进样、低压进样 放电池可以用于小样品和获得 极高的光谱分辨率。 与传统激光方法相比，激光方法的一些优点 传统的方法包括极高的灵敏度、选择性 和重现性，相对便宜的仪器，快速， 操作简单安全，分析性能稳定可靠 放射性同位素样品体积小，样品吞吐量快。 这些激光方法的有效性将被调查以 生物学研究中的一些最重要的元素，如 锂、钙、钡、铜、锌、镁、铅、镉、钒和铝。因为所有的同位素 目前(稳定的和放射性的)是同时测量的 超精细结构，这些激光方法也适用于 放射性同位素是绝对必要的研究。

The proposed research concerns the design and application of novel, ultra-sensitive, highresolution laser spectroscopic methods in measurement of metallobiochemically-important elements. For dietary availability and mineral absorption studies, the use of stable isotopes has provided an attractive alternative to radioisotopes due to the safety and ethical reasons. Although stable isotopes have been used frequently, the currently available stable isotope determination methodologies limit severely the full use of stable isotopes in biotracer studies. Even the most often used method, mass spectrometry, has many disadvantages including slow sample throughput, chemical interference and requirement of time-consuming sample purification and chelation steps. In this proposal, innovative, powerful, laser-based methods - optical phase conjugation spectroscopy and polarization spectroscopy - are presented to overcome many of the difficulties. These Doppler-free (and Lorentzian-free) laser spectroscopic methods yield spectral resolution high enough to resolve atomic/isotopic hyperfine structures - the spectroscopic fingerprints of atoms. Hence, excellent elemental/isotopic selectivity is obtained and spectral and chemical interference is virtually eliminated even if the sample contains a number of minerals. In addition to selectivity, these nonlinear laser methods also offer one of the most sensitive detection limits, and, hence, they have potential for isotope analysis at trace concentrations (ppm, and pptr) or for simple quantitative measurement of minerals in biological samples. These nonlinear laser methods employ multiple input laser beams to induce nonlinear effects in the sample and to generate signal beams. Cubic signal dependence on laser power in optical phase conjugation spectroscopy (and quadratic dependence in polarization spectroscopy) allows extremely effective use of high photon power available from lasers. Since signal is a laser beam, optical detection is very efficient. While analytical flame can be used as an atomizer to provide fast, convenient and continuous-flow sample introduction, a low-pressure discharge cell can be used for small samples and to obtain extremely high spectral resolution. Some of the advantages of the proposed laser methods over the conventional methods include excellent sensitivity, selectivity and reproducibility, relatively inexpensive instrumentation, rapid, simple and safe operation, capability of analyzing both stable and radioisotopes in small sample sizes, and fast sample throughput. The effectiveness of these laser methods will be investigated for some of the most important elements in biological studies such as Li, Ca, Ba, Cu, Zn, Mg, Pb, Cd, V, and A1. Since all isotopes present (stable and radioactive) are measured simultaneously in a hyperfine structure, these laser methods are also applicable to studies where radioisotopes are absolutely necessary.