激光诱导击穿光谱(LIBS)技术对水体中重金属元素的检测精度低是制约其发展的瓶颈问题, 针对不同的元素, 单双脉冲检测结果各有优势。为了综合比较单双脉冲对水体重金属Cr的检测效果, 试验运用集成ICCD的单、双脉冲LIBS分别对经滤纸富集后的6种不同质量浓度含Cr水溶液进行了试验。确立了Cr的特征分析谱线为 425.43 nm, 并对试验所得的数据进行了线性拟合, 建立了Cr元素浓度与其特征谱线LIBS强度定量分析模型, 对于单双脉冲, 拟合后的曲线相关系数分别为0.898 36和0.994 44, 斜率分别为22.693 86和30.539 77, 预测浓度与其真实浓度的相对误差分别为14.97%和4.52%。试验结果表明双脉冲的稳定度、灵敏度和准确度均较单脉冲好。

Laser induced breakdown spectroscopy(LIBS)is a novel technique in rapid and nondestructive analysis of constituents of materials.At the same time, the accuracy and precision of LIBS is low, which limit its development.To improve the analytical ability of LIBS, many measures are made.The optimization of instruments is one of methods.Single pulse LIBS(SPLIBS)and dual pulse LIBS(DPLIBS)have itself’s merits. In this work, in order to compare the detection results of Cr in solution by SPLIBS and DPLIBS, six different concentrations Cr solution enriched by filter paper were determined by SPLIBS and DPLIBS integrated ICCD respectively. The characteristics spectral lines of Cr in 425.43 nm was established, and the data was fitted by concentrations of Cr, and intensity of CrI425.43.The results showed that the correlation coefficients were 0.898 36 and 0.994 44, and the slope were 22.693 86 and 30.539 77 for SPLIBS and DPLIBS respectively. The relative error between predicted concentration and real concentration were 14.97% and 4.52% respectively. The experimental results demonstrated that the DPLIBS has better accuracy, stability, and sensitivity than SPLIBS.