铝合金中元素Cr和Cu的双脉冲激光诱导击穿光谱检测

采用共线双脉冲激光诱导击穿光谱(Dual pulse laser induced breakdown spectroscopy, DP-LIBS)技术分析铝合金中微量元素含量,详细研究了共线双脉冲光谱信号强度与 双脉冲间时间延迟的关系,最佳延时为8$\sim$9 $\mu$s。在该延时条件下,双脉冲光谱信号强度比单脉冲光谱 信号强度增强了10倍以上。分别采用双脉冲激光诱导击穿光谱和单脉冲激光诱导击穿光谱(Single-pulse laser induced breakdown spectroscopy, SP-LIBS)技术,得到了以Cu I 324.75 nm, Cr I 425.43 nm 谱线为分析线 的定标曲线。与采用单脉冲激光诱导击穿光谱技术相比,铝合金中 Cu和 Cr的检测极限分别由单脉冲时的169.5 和94.5 $\mu$g/g降低至双脉冲时的21.46 和4.26 $\mu$g/g。

Trace Cr and Cu Analysis in Aluminum Alloy by Double Pulse Laser-Induced Breakdown Spectroscopy

A collinear dual pulse laser induced breakdown spectroscopy (DP-LIBS) has been used for trace element analysis in aluminum alloy. The dependence of signal intensity on the inter-pulse delay time has been carefully investigated, which gives an optimized delay time of about 8$\sim$9 $\mu$s. For the two selected analytical lines Cu I 324.75 nm and Cr I 425.43 nm, more than 10 folds enhancement of line intensities have been obtained compared to that of single-pulse laser induced breakdown spectroscopy(SP-LIBS). Calibration curves for quantitative measurement of Cu and Cr were derived using both SP-LIBS and DP-LIBS techniques. The limit of detection (LOD) of elements Cu and Cr are found to be 21.46 and 4.26 $\mu$g/g respectively with DP-LIBS, while the LOD of elements Cu and Cr are 169.5 and 94.5 $\mu$g/g with SP-LIBS.