Sensitive and selective spectrochemical analysis of metallic samples: the combination of laser-induced breakdown spectroscopy and laser-induced fluorescence spectroscopy
Sensitive and selective spectrochemical analysis of metallic samples: the combination of laser-induced breakdown spectroscopy and laser-induced fluorescence spectroscopy
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DOI：
10.1016/s0584-8547(01)00190-2
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发表时间：
2001-06
期刊：
影响因子：
--
通讯作者：
H. Telle;D. Beddows;G. W. Morris;O. Samek
中科院分区：
文献类型：
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作者：
H. Telle;D. Beddows;G. W. Morris;O. Samek
为了提高分析选择性和灵敏度，将激光诱导荧光光谱（LIFS）技术与激光诱导击穿光谱（LIBS）相结合。这项调查的主要目的是解决测量站点可能难以访问的分析场景。因此，建立了远程LIBS+LIFS装置，并且实验是在大气压下的空气包围的样品上进行的，而不是在减压的受控缓冲气体环境中进行的。作为原理证明的代表，我们对痕量浓度的铝、铬、铁和硅进行了检测。这些元素在众多化学、医疗和工业应用中非常重要，并且它们表现出适当的共振跃迁，可通过脉冲钛宝石激光系统（其二次和三次谐波输出）的辐射实现。所有研究的元素都具有能级结构，其中激光激发能级是一组紧密排列的能级中的一个；因此，这使得非共振荧光检测变得容易（碰撞能量转移过程）。由于许多相关的跃迁波长都在狭窄的光谱区间内，这为多元素分析提供了可能性；这里对 Cr 和 Fe 进行了演示，通过快速改变可调谐激光波长来获取它们。
In order to improve on analytical selectivity and sensitivity, the technique of laser-induced fluorescence spectroscopy (LIFS) was combined with laser-induced breakdown spectroscopy (LIBS). The main thrust of this investigation was to address analytical scenarios in which the measurement site may be difficult to access. Hence, a remote LIBS+LIFS arrangement was set up, and the experiments were carried out on samples surrounded by air at atmospheric pressure, rather than in a controlled buffer gas environment at reduced pressure. Representative for proof of principle, the detection of aluminium, chromium, iron and silicon at trace level concentrations was pursued. These elements are of importance in numerous chemical, medical and industrial applications, and they exhibit suitable resonance transitions, accessible by radiation from a pulsed Ti:sapphire laser system (its 2nd and 3rd harmonic outputs). All investigated elements have an energy level structure in which the laser-excited level is a member of a group of closely-spaced energy levels; thus, this allowed for easy off-resonant fluorescence detection (collisional energy transfer processes). Since numerous of the relevant transition wavelengths are within a narrow spectral interval, this opens the possibility for multi-element analysis; this was demonstrated here for Cr and Fe which were accessed by rapidly changing the tuneable laser wavelength.