This study used laser-induced breakdown spectroscopy (LIBS) combined with spark discharge (SD) and an electro-deposition method to analyze trace heavy metal Pb in an aqueous solution. First, the electro-deposition method was used to enrich the trace heavy metal Pb element in an aqueous solution on the surface of a high-purity Al plate with an enrichment voltage of 8 V and an enrichment time of 10 min, thereby overcoming the problem of low sensitivity and accuracy in the direct detection of water samples by LIBS. Second, SD-LIBS was used to detect the Pb element on the surface of the Al plate to enhance the emission intensity of Pb(I). Finally, the calibration curves of Pb(I) at 405.78 nm were plotted for different discharge voltages (0, 2, and 4 kV), and it was found that at higher discharge voltage, the slope (S) of the calibration curve increased and the limit of detection (LOD) decreased. The S values were 0.0403 (0 kV), 0.1643 (2 kV), and 0.2853 (4 kV), and the LODs were 53.5 (0 kV), 13.1 (2 kV), and 7.5 (4 kV) ng mL⁻¹. Therefore, the combination of the electro-deposition method and the SD-LIBS technique can realize higher sensitivity detection of trace heavy metals in aqueous solutions.

中文翻译：

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使用电沉积和火花放电辅助激光诱导击穿光谱法对水溶液中痕量铅进行高灵敏度分析

本研究使用激光诱导击穿光谱 (LIBS) 结合火花放电 (SD) 和电沉积方法分析水溶液中的痕量重金属 Pb。首先，采用电沉积法在高纯铝板表面富集水溶液中的痕量重金属Pb元素，富集电压为8 V，富集时间为10 min，从而克服了该问题。 LIBS 直接检测水样的灵敏度和准确度较低。其次，SD-LIBS 被用来检测铝板表面的 Pb 元素，以增强 Pb( I )的发射强度。最后，Pb( I) 在 405.78 nm 处针对不同的放电电压 (0、2 和 4 kV) 进行绘图，发现在更高的放电电压下，校准曲线的斜率 ( S ) 增加，检测限 (LOD) 降低。S 值为 0.0403 (0 kV)、0.1643 (2 kV) 和 0.2853 (4 kV)，LOD 为 53.5 (0 kV)、13.1 (2 kV) 和 7.5 (4 kV) ng mL ^-1。因此，将电沉积法与SD-LIBS技术相结合，可以实现对水溶液中痕量重金属的更高灵敏度检测。