Skočovská Katarína, Novotný Jan, Prochazka David, Pořízka Pavel, Novotný Karel, Kaiser Jozef
Institute of Physical Engineering, Faculty of Mechanical Engineering, Brno University of Technology, Brno, Czech Republic.
CEITEC - Central European Institute of Technology, Brno University of Technology, Brno, Czech Republic.
Rev Sci Instrum. 2016 Apr;87(4):043116. doi: 10.1063/1.4947233.
A complex optimization of geometrical and temporal parameters of a jet system (developed in Laser-induced breakdown spectroscopy (LIBS) laboratory of Brno University of Technology) for direct elemental analysis of samples in a liquid state of matter using LIBS was carried out. First, the peristaltic pump was synchronized with the flashlamp of the ablation laser, which reduced variation of the ablated sample amount. Also, the fluctuation of the laser ray angle incident on the jet surface was diminished. Such synchronization reduced signal standard deviations and thus increased repeatability of the measurements. Then, laser energy and distance of the focusing lens from the sample were optimized. The gate delay time and the gate width were optimized for single pulse (SP) experiments; the gate delay time and the inter-pulse delay were optimized for the use of double pulse (DP) variant. Results were assessed according to the highest signal to noise ratios and the lowest relative standard deviations of the signal. The sensitivity of the single pulse and the double pulse LIBS for the detection of heavy metals traces, copper (Cu i at 324.754 nm) and lead (Pb i at 405.781 nm), in aqueous solution of copper (ii) sulfate and lead (ii) acetate, was estimated in terms of limits of detection (LODs). As a result, sensitivity improvement of DP LIBS system was observed, the LOD of Cu obtained with DP was calculated 40% lower than LOD gained from SP technique.
对喷射系统（由布尔诺理工大学激光诱导击穿光谱学（LIBS）实验室研发）的几何和时间参数进行了复杂优化，以便使用LIBS对液态物质中的样品进行直接元素分析。首先，蠕动泵与烧蚀激光的闪光灯同步，这减少了烧蚀样品量的变化。此外，入射到喷射表面的激光束角度的波动也减小了。这种同步降低了信号标准差，从而提高了测量的重复性。然后，对激光能量和聚焦透镜与样品之间的距离进行了优化。针对单脉冲（SP）实验优化了门延迟时间和门宽度；针对双脉冲（DP）变体的使用优化了门延迟时间和脉冲间延迟。根据最高的信噪比和最低的信号相对标准差对结果进行评估。根据检测限（LOD）评估了单脉冲和双脉冲LIBS对硫酸铜（ii）和醋酸铅（ii）水溶液中重金属痕量铜（324.754 nm处的Cu i）和铅（405.781 nm处的Pb i）的检测灵敏度。结果表明，观察到双脉冲LIBS系统的灵敏度有所提高，双脉冲获得的铜的检测限经计算比单脉冲技术获得的检测限低40%。
