中文摘要：

为使激光诱导击穿光谱技术（LIBS）能实际应用于环境污染相关的领域,选择新鲜桔叶片样品作初步实验研究。该实验用纳秒级Nd：YAG激光器（波长：1 064 nm）为光源,在实验室自然大气环境下诱导新鲜桔叶片产生等离子体,研究了延时时间和激光能量对新鲜桔叶片中铬元素激光诱导击穿光谱特性的影响,综合评价其信背比和信号强度得到了相应的最佳检测条件：最佳延时1.6μs,最佳激光能量120 mJ。建立了Cr元素的定标曲线,并且定量分析了在最佳实验条件下样品中铬元素浓度。结果表明Cr元素浓度在50～800μg/mL范围内,Cr元素含量和光谱相对强度之间有较好的线性关系。实验也表明LIBS技术是一种快速检测新鲜植物叶片中重金属元素含量的有效工具。

英文摘要：

To effectively employ LIBS technique in the field related to environmental pollution,primary experiments have been done in fresh orange leaf samples.Laser-induced breakdown spectroscopy（LIBS） is a burgeoning element analysis method.In the experiment,plasma in fresh orange leaf was induced using nanosecond Nd：YAG（wavelength：1 064 nm） laser as the excitation source in the atmospheric environment of the laboratory.The influence of the delay time and laser energy on spectral characteristics of element Cr in fresh plants was studied.Through evaluation of the signal-to-background ratio and Cr line intensity,the best delay time 1.6 μs and the best laser energy 120 mJ were found.The calibration curve of element Cr was measured by studying the features of LIBS of element Cr in fresh plant under optimal conditions.The experimental results indicate that there is a good linear correlation between the element content 50~800 μg/mL and the relative intensity of spectral line.The experiment also shows that LIBS technology is a kind of fast effective means to detect metal elements in fresh plants.