液相基质中重金属元素激光诱导击穿光谱实验参数的优化

针对混合溶液中重金属元素的激光诱导击穿光谱(LIBS)测量系统,为提高测量系统的检测灵敏度,以提高混合溶液中Ca和Cr金属元素LIBS光谱线强度的信噪比为目标,对LIBS测量系统中的激光脉冲能量、液相样品流速、ICCD门宽、延时等实验参数进行了优化,得到最优化参数激光脉冲能量、样品流速、ICCD门宽、延时分别为35 m J、30 ml/min、1400 ns和2400 ns,为降低LIBS技术应用于混合溶液中痕量重金属元素的检出限提供了实验参数支撑.

Optimization of experimental parameters of LIBS of heavy metal elements in liquid matrix

In the laser induced breakdown spectroscopy (LIBS) system for measuring the heavy metal elements in mixed solution, the experimental parameters such as laser pulse energy, liquid sample flow velocity, ICCD gate width, and delay were optimized with the aim to enhance the signal to noise ratio of LIBS spectra line intensity of the Ca and Cr elements in the mixed solution. The optimum parameters obtained are 35mJ for laser pulse energy, 30ml/min for sample flow velocity, 1400ns for ICCD gate width and 2400ns for ICCD gate delay respectively. These results provide experimental parameters support to reduce the limit of detection of the LIBS technology applied to quantitative analysis of trace heavy metal elements in the mixed solution. Key words: Laser Induced Breakdown Spectroscopy, Liquid Matrix, Heavy Metal Elements, Experimental Parameters Optimization.