杨树叶片的飞秒等离子体丝诱导击穿光谱研究

开展了杨树叶片的飞秒激光等离子体丝诱导击穿光谱研究, 定性比较分析了长春市区的第一汽车厂、火车站、净月潭公园及长春理工大学四个地理区域的杨树叶片中重金属元素Ca, Fe和Cr. 实验结果表明, 通过分析杨树叶片中Ca Ⅱ 393.37 nm和Fe Ⅰ 422.87 nm光谱谱线可知叶茎中Ca和Fe元素浓度均高于叶肉. 比较长春四个地理区域的杨树叶的飞秒激光等离子体丝诱导击穿光谱, 发现汽车厂附近的杨树叶内重金属Ca, Fe和Cr 元素浓度最高, 净月公园的杨树叶重金属浓度最低. 由于飞秒激光等离子体丝光强度的“光学钳箍”效应, 对于杨树叶片这种表面不平整样品, 仍可获得稳定性较好的等离子体光谱. 飞秒激光等离子体丝诱导光谱技术有望在环境污染在线检测具有广泛的潜在应用.

Analysis of heavy metals in poplar leaves by femtosecond filament-induced breakdown spectroscopy

Femtosecond filament-induced breakdown spectroscopy (FIBS) is employed to qualitatively analyze the heavy metal elements (Ca, Fe and Cr) in poplar leaves, at the same age, from four representative locations in Changchun City, i.e. Changchun First Automobile Factory, Railway Station, Jingyue National Forest Park, and Changchun University of Science and Technology (CUST) in the same season. The stem and mesophyll from the same leaf are investigated as samples by the FIBS technique. Experimental results demonstrate that the concentration of Ca and Fe elements in the leaf stem are higher than those in the leaf mesophyll through comparing the spectral intensities of Ca Ⅱ 393.37 nm and Fe Ⅰ 422.87 nm. Based on the analysis of the FIBS spectral intensity of heavy metals mentioned above in the poplar leaves from the four different locations, the heavy metal elements Ca, Fe and Cr in the poplar leaves gathered from the Automobile factory area have the highest concentration among the four locations, and those from Jingyue National Forest Park are the lowest. The FIBS technique can obtain stable plasma spectrum for the poplar leaves with irregular surfaces because of the optical intensity clamping effect inside the femtosecond filament. This experiment demonstrates that FIBS can be utilized to find new applications in the environmental pollution on-site detection.