基于双脉冲LIBS结合偏最小二乘回归的稀土元素定量分析

激光诱导击穿光谱(LIBS)是一种以激光为激发源的等离子体发射光谱分析技术，已有将其用于稀土元素的定量分析研究，但由于稀土矿基体差异大、元素含量低，定量分析灵敏度和准确度仍有待提高。通过使用单激光分束构造双脉冲LIBS系统，并结合偏最小二乘回归(PLSR)算法实现对稀土矿石样品中的稀土元素La、Dy、Yb和Y的定量分析。结果表明，双脉冲LIBS结合PLSR可建立更加稳定的定标模型，与常规基本定标法相比，La、Dy、Yb和Y元素的相对均方根预测误差(RMSEP)从0.0061 %、0.0037%、0.0045%、0.0280 %降低至0.0044%、0.0016%、0.0029%、0.0134%，平均相对预测误差(AREP)从10.88%、15.27%、6.42%、17.20%降低至6.67%、3.62%、4.10%、7.98%。因此，双脉冲LIBS结合PLSR方法可以有效地提高LIBS对稀土矿石中稀土元素的定量分析能力。

Quantitative Analysis of Rare Earth Elements Based on Double-pulse LIBS Combined with Partial Least Squares Regression

Laser-induced breakdown spectroscopy (LIBS) is a plasma emission spectroscopy analysis technique using laser as the excitation source, which has been used for the quantitative analysis of rare earth elements, but the sensitivity and accuracy of quantitative analysis still need to be improved due to the large difference in rare earth ore matrix and low element content. In this paper, we propose to construct a double-pulse LIBS system using a single laser beam splitting system, and combine it with the partial least squares regression (PLSR) algorithm to realize the quantitative analysis of rare earth elements La, Dy, Yb and Y in rare earth ore samples. Compared with the conventional basic calibration method, the relative root mean square prediction error (RMSEP) of La, Dy, Yb and Y elements is reduced from 0.0061%, 0.0037%, 0.0045%, and 0.0280% to 0.0044%, 0.0016 %, 0.0029%, and 0.0134%, The mean relative prediction error (AREP) decreased from 10.88%, 15.27%, 6.42%, and 17.20% to 6.67%, 3.62%, 4.10%, and 7.98%. Therefore, the combination of double-pulse LIBS and PLSR method can effectively improve the quantitative analysis ability of LIBS for rare earth ores.