The plasma emission spectrum of uranium in laser-induced breakdown spectroscopy (LIBS) is weak and susceptible to spectral interference, especially in a complex ore matrix. In this study, laser-induced breakdown spectroscopy combined with laser-induced fluorescence (LIBS-LIF) technology was proposed to enhance the spectral intensity of uranium in ores and eliminate spectral interference. Different combinations of excitation lines and analytical lines of the U element were investigated. In contrast with atomic lines, uranium ion lines are more suitable for determination of uranium. The relative number of U ions in plasma was studied for the best selection of excitation lines and analytical lines. The analytical performance of LIBS-LIF and LIBS for U determination in ores was compared. The results showed that all indicators had been significantly improved by LIBS-LIF. The slope, R², LoD, RMSECV, ARE, and ARSD values of LIBS-LIF were 1.1 × 10⁵ counts per wt%, 0.998, 35 μg g⁻¹, 0.05 wt%, 6.69%, and 6.37%, respectively. This work demonstrates that LIBS-LIF has excellent potential in the exploration of uranium resources.

中文翻译：

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激光诱导击穿光谱结合激光诱导荧光测定矿石中的铀

激光诱导击穿光谱法（LIBS）中铀的等离子体发射光谱很弱，容易受到光谱干扰，特别是在复杂的矿石基质中。在这项研究中，提出了结合激光诱导荧光（LIBS-LIF）技术的激光诱导击穿光谱法，以提高矿石中铀的光谱强度并消除光谱干扰。研究了U元素的激发线和分析线的不同组合。与原子线相反，铀离子线更适合于铀的测定。为了最佳选择激发线和分析线，研究了等离子体中U离子的相对数量。比较了LIBS-LIF和LIBS对矿石中U的分析性能。结果表明，LIBS-LIF显着改善了所有指标。斜率，[R ²，的LoD，RMSECV，ARE和LIBS-LIF的ARSD值分别为1.1×10 ⁵每重量％计数，0.998，35微克克^-1，0.05重量％，6.69％，和6.37％之间。这项工作表明，LIBS-LIF在勘探铀资源方面具有极好的潜力。