土壤中砷元素的激光诱导击穿光谱测量分析

利用Nd:YAG脉冲激光器作为光源,在实验室自然大气环境下诱导产生国家标准土壤的激光等离子体,选取砷的228.8nm特征谱线作为分析线,测量并分析了砷元素的激光诱导击穿光谱特性。在相同含量和积分时间条件下,调节延迟时间,获取了砷元素的时间演化特性。确定砷元素的最佳延迟时间为1μs,积分时间为2μs。测定不同含量下,砷的特征谱线强度,给出砷元素的定标曲线,并计算得到砷元素的检测限为45mg/kg。

Measurement and analysis of arsenic in soil using laser-induced breakdown spectroscopy

This paper analyzed the characteristics of laser-induced breakdown spectroscopy (LIBS) of metal element arsenic in soil using the Nd:YAG (wavelength: 1064 nm) laser as the excitation source, where the spectral signals were detected by the high resolved, wide spectral ECHELLE spectrograph and intensity charged coupled device (ICCD). The time evolution of the characteristic spectral line of arsenic was obtained by changing the delay time of ICCD at the same concentration and the gate of ICCD with wavelength of 228.8 nm of arsenic as the characteristic spectral line, from which a best delay time of 1 s and a gate width of 2 s were found. By measuring the intensities of the characteristic spectral line with different arsenic concentrations, it was demonstrated that the intensities of the spectral line increased with the concentration of arsenic under the condition of low concentration. From the results, the LIBS calibration curve of arsenic was obtained, and the detection limit of arsenic in soil at 45 mg/kg was obtained.