激光诱导荧光光谱分析法研究(Ⅸ)Dy-AA-TOPO-SLS的发光机理及分析应用

本文采用自己组装的激光诱导荧光光谱测定装置,研究了镝-乙酰丙酮-三正辛基膦化氧(Dy-AA-TOPO)体系在表面活性剂十二烷基磺酸钠(SLS)存在时的吸收光谱特性和激光诱导发光光谱特性,首次在室温测得AA的磷光发射.并从配体、中心离子的化学性质和所形成配合物的对称性及它们的光谱能级等方面综合考虑,提出配合物体系的发光机理和荧光发射过程中的能量传递方式.共存离子对配合物体系荧光发射强度的影响表明,在一定浓度范围内,某些稀土和非稀土离子可产生荧光增强作用,即“协同发光”效应.拟定出测定痕量镝的激光诱导荧光分析方法,对于单个激光脉冲产生的荧光,镝的工作曲线的线性范围为1-200ppb.用于高纯氧化钇中痕量镝的测定,获得了满意的结果.

STUDIES ON LASER-INDUCED FLUORIMETRY(IX) THE LUMINESCENCE MECHANISM AND ANALYTICAL APPLICATION OF Dy-AA-TOPO-SLS FLUORESCENT SYSTEM

The absorption spectrum and the laser-induced luminescent spectrum of dysprosium-acetylacetone-tri-n-octylphosphine oxide (Dy-AA-TOPO) in the micellar solution of anionic surfactant sodium lauryl sulfo-nate (SLS) were studied using homemade laser fluorimeter. Basic components of experimental apparatus for laser fluorimeter are an actively Q-switched Nd:YAG-pumped dye laser as the excitation light source, a SIT vidicon optical multichannel analyzer as the luminescence detecting equipment and an electric trigger made by our laboratory as the external trigger source. The phosphorescent emission of AA was determined for the first time at room temperature. The luminescence mechanism and a two-step energy transfer process are proposed.The energy transfers from the donor TOPO to the acceptor AA and from the donor AA to the acceptor dysprosium ion. The AA acts both the donor and the acceptor.Dy-AA*-TOPO*-Dy*-AA*-TOPO-Dy*-AA-TOFO+hv-Dy-AA-TOPO+hvThe Dy-AA-TOPO-SLS system is adopted in the determination of the trace dysprosium. The calibration curve is linear over the range of 1-200 ng Dy/ml. A new sensitive fluorescence phenomenon is observed by adding some of metal ions, which is named synergistic luminescence. Results are setisfactory for the determination of dysprosium in highly pure ytterbium oxide and synthetic samples without pre-separation.