光学学报, 2017, 37(11): 1130001, 网络出版: 2019-05-09
Super Sensitive Detection of Lead in Water by Laser-Induced Breakdown Spectroscopy Combined with Laser-Induced Fluorescence Technique
华南理工大学物理与光电学院, 广东 广州 510641
光谱学 激光诱导击穿光谱 激光诱导荧光 铅 超灵敏检测 水 spectroscopy laser-induced breakdown spectroscopy laser-induced fluorescence lead super sensitive detection water
To realize the super sensitive detection of the toxic heavy metal element lead and to ensure safety of drinking water, we study the combined technique of laser-induced breakdown spectroscopy (LIBS) with laser-induced fluorescence (LIF) technique. A wood slice is used to absorb water to convert liquid samples analysis into solid samples analysis, which eliminates the influence of water on atomic emission as well as an optical collecting system in direct analysis of liquid samples with LIBS. Meanwhile, a beam of tunable dye laser is used to excite lead atoms in laser-induced plasma resonantly, and LIF of lead is detected to improve its spectral analysis sensitivity significantly. A calibration curve of lead in water is obtained under optimized experimental conditions. The detection limit of lead in water is determined to be 3.2×10 -9 under current experimental conditions. It is demonstrated that the LIBS-LIF technique combined with the method of selecting a wood slice as a water absorber can be applied to realize direct, fast, and super sensitive detection of trace lead in water, thus the water pollution due to toxic heavy metals can be monitored.