Wang Yuan-yuan, Zhao Nan-jing, Ma Ming-jun, Fang Li, Yu Yang, Meng De-shuo, Gu Yan-hong, Jia Yao, Liu Jian-guo, Liu Wen-qing
Guang Pu Xue Yu Guang Pu Fen Xi. 2017 Mar;37(3):884-8.
In order to improve the detection sensitivity of laser-induced breakdown spectroscopy (LIBS) and lower the limit of the detection of elements, LIBS combined with Aluminum electrode enrichment method is adopted to analyze heavy metals such as Pb,Cdand Ni in the water. The relationship between the characteristic spectral intensity and the key parameters-voltage of electrode method is discussed, the spectral intensity increases first and then decreases with the increase of voltage. The spectral intensity reaches the maximum value when the enrichment voltage is 1.2 V while the optimal enrichment voltage value is 1.2 V. The stability of characteristic spectral lines of heavy metals is studied, and the relative standard deviation(RSD) of spectral intensity of Pb, Cd and Ni is 5.98％，4.25 ％ and 5.27％ respectively, the result shows that the spectral line obtained by this method has high stability. A series of samples in the range of 0~0.13 mg·L-1 are prepared and quantitatively analyzed, the limit of detection of Pb, Cd and Ni is obtained 1.2，3.1 and 1.7 ppb respectively. The above result shows that LIBS combined with aluminum electrode enrichment method can effectively improve the stability of characteristic spectral lines and lower the limit of detection of Pb,Cd and Ni. This research also provides a method to further improve detection sensitivity of LIBS and analysis ability of heavy metal in the water.
为了提高激光诱导击穿光谱法（LIBS）的检测灵敏度并降低元素检测限，采用LIBS结合铝电极富集法对水中的Pb、Cd和Ni等重金属进行分析。讨论了特征光谱强度与电极法关键参数——电压之间的关系，光谱强度随电压升高先增大后减小。当富集电压为1.2 V时光谱强度达到最大值，最佳富集电压值为1.2 V。研究了重金属特征谱线的稳定性，Pb、Cd和Ni光谱强度的相对标准偏差（RSD）分别为5.98％、4.25％和5.27％，结果表明该方法获得的谱线具有较高的稳定性。制备了一系列浓度范围为0~0.13 mg·L-1的样品并进行定量分析，得到Pb、Cd和Ni的检测限分别为1.2、3.1和1.7 ppb。上述结果表明，LIBS结合铝电极富集法可有效提高特征谱线的稳定性并降低Pb、Cd和Ni的检测限。本研究还为进一步提高LIBS的检测灵敏度及水中重金属的分析能力提供了一种方法。
