Abstract Measurements of boron isotopic ratios have been investigated using LIBS, and combined LIBS and Molecular laser-induced fluorescence (MLIF). Mixtures of various ratios of research grade H310BO3 and H311BO3 in pellet form were interrogated with a Q-switched Nd:YAG laser operating at 532 nm. The resulting plasma was examined for their BO molecular bands in the 254–262 nm and 266–276 nm wavelength ranges. A minimum of three band heads of the β system B2Σ → X2Σ transitions were identified. The rovibronic isotopic shifts of the corresponding bands were measured and were conclusively compared to the literature. MLIF was applied to LIBS emission lines covering 253–271 nm to enhance some band heads, selectively. Both LIBS and LIBS-MLIF emissions were subject to multivariate statistical analysis to predict 10B isotopic ratios. Two PLS regression calibration models were examined to better examine the effects, sensitivity, accuracy of the laser-produced plasma excitation modalities based models through the figure of merit. For the full calibration set (21 samples), the root mean square error of cross-validation (RMSECV), the pseudo univariate LOD (LODpu) and the LOD interval ([LODmin, LODmax]) for 10B isotopes were improved from 1.61%, 4.81%, [2.64%, 3.49%] 10B isotopic ratio, respectively for LIBS to 0.98%, 2.40%, [2.19%, 2.81%] 10B isotopic ratio, respectively for LIBS-MLIF. However, using a random subset of the samples (14) as a calibration set and the rest as a test set, the root mean square error of prediction of 10B isotopic ratio in the test set improved from 2.95% to 1.16% 10B isotopic ratio, respectively for LIBS and LIBS-MLIF; and the LOD interval improved from [2.45%, 2.69%] to [1.88%, 2.12%] 10B isotopic ratio when calculated with cross-validated residual variance. Moreover, the prediction error of a test set improved from 2.95% for LIBS to 1.16% for LIBS-MLIF.

中文翻译：

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使用多个 BO 分子发射通过 LIBS 多变量测定 10B 同位素比率

摘要 已经使用 LIBS 以及结合 LIBS 和分子激光诱导荧光 (MLIF) 研究了硼同位素比率的测量。研究级 H310BO3 和 H311BO3 的各种比例混合物以颗粒形式使用 532 nm 的 Q 开关 Nd:YAG 激光器进行询问。检查所得等离子体在 254-262 nm 和 266-276 nm 波长范围内的 BO 分子带。至少确定了 β 系统 B2Σ → X2Σ 转变的三个带头。测量了相应条带的 rovibronic 同位素位移，并最终与文献进行了比较。MLIF 应用于覆盖 253-271 nm 的 LIBS 发射线，以选择性地增强一些带头。LIBS 和 LIBS-MLIF 排放都经过多变量统计分析以预测 10B 同位素比率。检查了两个 PLS 回归校准模型，以通过品质因数更好地检查基于激光产生的等离子体激发模式的模型的效果、灵敏度和准确性。对于完整的校准集（21 个样本），交叉验证的均方根误差 (RMSECV)、伪单变量 LOD (LODpu) 和 10B 同位素的 LOD 间隔 ([LODmin, LODmax]) 从 1.61% 提高， LIBS 的 4.81%、[2.64%、3.49%] 10B 同位素比率分别为 LIBS-MLIF 的 0.98%、2.40%、[2.19%、2.81%] 10B 同位素比率。然而，使用样本（14）的随机子集作为校准集，其余作为测试集，测试集中10B同位素比的预测均方根误差从2.95％提高到10B同位素比的1.16％，分别用于 LIBS 和 LIBS-MLIF；当使用交叉验证的残差方差计算时，LOD 间隔从 [2.45%, 2.69%] 提高到 [1.88%, 2.12%] 10B 同位素比率。此外，测试集的预测误差从 LIBS 的 2.95% 提高到 LIBS-MLIF 的 1.16%。