应用激光诱导击穿光谱检测污水溶液中的砷

工业冶炼过程中产生的废水中含有As等重金属元素，对环境造成污染并对人类身体健康形成危害，有必要对其进行实时、在线的监测。激光诱导击穿光谱(LIBS)是一种新型的元素测量技术，具有快速检测等优点。文章作者搭建了一套激光诱导击穿光谱实验装置，采用Nd∶YAG激光器产生的脉冲激光击穿样品产生等离子体，其发射的光谱被中阶梯光栅光谱仪分光，并用ICCD进行光电探测。对从现场采集的含砷工业废水开展了LIBS探测实验，并定性分析出了As元素的特征谱线。根据一系列含As浓度不同的污水样品的LIBS实验结果，获得元素浓度与谱线强度的关系曲线(定标曲线)。采用定标曲线可以对未知含As浓度的工业废水进行定量分析。结果表明，采用LIBS方法能够实现对污水溶液中的As元素的快速检测，具有广泛的应用前景。

Determination of As in Industrial Wastewater by Laser-Induced Breakdown Spectroscopy

The wastewater from industrial smelting process contains heavy metals such as arsenic (As) that produce serious environmental pollution and cause actual harm to the health of people. It is necessary to control the pollution at the source and achieve a real-time and online monitoring. The laser-induced breakdown spectroscopy (LIBS) is a new elemental analysis technique, and has the advantage of rapid detection. An LIBS setup has been established. The Nd∶YAG laser beam is focused onto the sample, then the plasmas are produced. The emission spectra of plasmas are dispersed by an Echelle spectrograph and detected by an intensified charge-coupled device (ICCD). Experiments have been carried out on the industrial wastewater collected from the scene. The spectral lines of As element were obtained. The calibration curve of the line intensities versus the concentrations of the As element was acquired by the experiment. The calibration curve can be used for the quantitative analysis of arsenic element with an unknown concentration in the industrial wastewater. The results showed that the LIBS technique can be applied in the rapid detection of As element in industrial wastewater, and has wide range of applications.