To realize ultrasensitive detection of trace amounts of lead in water, laser-induced breakdown spectroscopy combined with laser-induced fluorescence (LIBS-LIF) was investigated. A wood-slice substrate was selected: (i) as a water absorber to convert liquid-sample analysis to solid-sample analysis; (ii) to eliminate the influence of a water matrix to spectral analysis (e.g., light blocking due to water splashing and plasma emission quenching due OH groups) in the plasma during direct analysis of water samples. The wood slice after treatment was ablated by a Q-switched Nd:YAG laser to produce plasma. Then, the lead atoms in the plasma were re-excited by a second tunable dye laser resonantly. The LIF signal of lead was detected to improve its sensitivity to spectral analysis significantly. Under the assistance of this matrix-converting method, the calibration curve of lead in water samples was created and the limit of detection was found to be 0.32 ppb, two orders of magnitude better than that obtained by analyzing water samples directly using the same LIBS-LIF technique. This sample-pretreatment procedure was rapid and easy to handle. Upon combination with LIBS-LIF, ultrasensitive detection of trace amounts of toxic metal elements in water could be realized. This approach could be applied in water-quality control and monitoring of environmental pollution.

中文翻译：

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LIBS-LIF使用木片基材作为吸水剂超灵敏地检测水中的痕量铅

为了实现水中痕量铅的超灵敏检测，研究了结合激光诱导荧光（LIBS-LIF）的激光诱导击穿光谱仪。选择木片基材：（i）作为吸水剂，将液体样品分析转换为固体样品分析；（ii）消除水基质对光谱分析的影响（例如，在直接分析水样品期间等离子体中由于水飞溅引起的光阻挡和由于OH基团引起的等离子体发射淬灭）。处理后的木片用调Q Nd：YAG激光烧蚀，产生等离子体。然后，通过第二可调染料激光器共振激发等离子体中的铅原子。检测到铅的LIF信号可显着提高其对光谱分析的灵敏度。在这种矩阵转换方法的帮助下，创建了水样品中铅的校准曲线，发现检出限为0.32 ppb，比使用同一LIBS-直接分析水样品获得的检出限好两个数量级。 LIF技术。该样品预处理过程快速且易于处理。与LIBS-LIF结合使用后，可以实现水中痕量有毒金属元素的超灵敏检测。该方法可用于水质控制和环境污染监测。