基于内标CF-LIBS的混合水溶液中多金属元素的定量分析

Internal standard CF-LIBS for quantitative analysis of multiple metal elements in mixed aqueous solutions

提出一种简化内标自由定标激光诱导击穿光谱(CF-LIBS)分析方法,并应用于混合水溶液中Cr、Mn、Pb、Cd、Ca、Al、Co等金属元素绝对浓度的定量分析.实验结果表明,在最优化实验参数下产生的激光等离子体满足局部热平衡和光学薄条件,由该分析方法得到的LIBS检测精确度明显优于采用液固转换后的传统CF-LIBS方法,测定的浓度值与配置值的相对误差小于1%,说明应用该内标CF-LIBS方法能够同时精确测定液相基质中的多种微量金属元素的含量.

A simpler internal standard method of Calibration-free laser induced breakdown spectroscopy(CF-LIBS)was presented and applied to the quantitative analysis of the concentrations of metal elements Cr,Mn,Pb,Cd,Ca,Al,and Co in prepared mixed aqueous solutions.Our experimental results confirmed the satisfactions with the local thermal equilibrium and optical thin conditions of the laser induced plasma under the optimized experimental parameters.The analysis results showed that the accuracy of LIBS detection is significantly improved compared to the normalized limiting CF-LIBS methods of liquid to solid conversion samples,with a relative error of less than 1%compared to the preparation value.We concluded that this internal standard CF-LIBS method can be applied to the simultaneous and accurate determination of multiple trace metal elements in liquid phase matrices.