A dynamic model for the elucidation of a mechanism of analyte transformation in an inductively coupled plasma.
A dynamic model for the elucidation of a mechanism of analyte transformation in an inductively coupled plasma.
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用于阐明电感耦合等离子体中分析物转化机制的动态模型。
DOI：
10.1021/ac00166a023
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发表时间：
1988
影响因子：
7.4
通讯作者：
Winefordner,JD
中科院分区：
文献类型：
--
作者：
Li,KP;Dowling,M;Fogg,T;Yu,T;Yeah,KS;Hwang,JD;Winefordner,JD
分析物分子、原子和离子物质的轴向信号轮廓包含分析物转化机制研究所必需的信息。从理论上讲，这种分布比径向分布更容易处理，因为中心通道的异质性比等离子体中的任何其他部分要少得多。在空间分辨测量中经常研究的大区域使得传统的基于局部热平衡的模型不适合机理阐明。建立了更一般的动态模型，其中平衡和稳态被视为特殊情况。考虑了解离、原子化、电离和重组等限速反应的动力学。为了数学简化，我们想象蒸气羽流是由单个气溶胶颗粒产生的，然后密切关注发生的动力学过程。在我们的例子中，扩散近似为恒定压力下的体积膨胀。假设感应耦合等离子体具有可重复的实验条件和均匀的溶液液滴尺寸分布，则观察到的最终分析物分布应该非常接近真实的分析物分布。通过将使用不同速率常数的模拟高度轮廓与实验高度轮廓进行比较，可以更精确地描述分析物转化。另一方面，实验高度剖面的测量和统计矩的评估应该可以估计反应速率常数。
Axial signal profiles of analyte molecular, atomic, and Ionic species contain Information essential for mechanistic studies of analyte transformation. Such profiles are easier to deal with theoretically than radial profiles because the central channel Is much less heterogeneous than any other part In the plasma. The large regions often Investigated In spatially resolved measurements render the conventional local thermal equilibrium-based models Inappropriate for mechanism elu-cidation. A more general dynamic model Is established, where equilibria and steady states are considered as special cases. Kinetics of rate-determining reactions such as disso-ciation, atomization, Ionization, and recombination are con-sidered. For mathematical simplification, we Imagine that the vapor plume results from a single aerosol particle, and the kinetic processes taking place are then closely followed. In our case, diffusion Is approximated as volume expansion un-der constant pressure. The resultant analyte distribution observed should then be a good approximation to the real one, assuming an Inductively coupled plasma with reproducible experimental conditions and a uniform solution droplet size distribution. By comparison of the simulated height profiles using different rate constants with experimental height pro-files, analyte transformation can be more precisely described. On the other hand, measurements of experimental height profiles and evaluation of statistic moments should allow es-timation of reaction rate constants.