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本文研究了在 p H9.2~ 9.5氨性缓冲溶液中 ,Cu( )催化 H2 O2 氧化溴酚蓝和丁基罗丹明 B等色染料离子对褪色的新指示反应 ,建立了较为广泛的快速终止催化反应的新方法。本方法测定铜 ,灵敏度为 0 .0 2μg·L- 1 ,线性范围为 0 .1~ 10 μg· L- 1。用于直肠癌组织中微量元素铜的测定 ,结果满意 相似文献
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在研究共存离子对稀土配合物荧光强度影响时发现,许多稀土和非稀土离子在一定浓度范围内可对配合物的荧光产生增强效应.这种现象与协同萃取类似,我们将其命名为“协同发光效应”.本文采用激光诱导荧光光谱法,研究了十四种稀土离子对Eu、Sm-TTA-Phen-Triton X-100体系和Eu、Sm-DBM-CPB体系的协同发光效应.并从稀土离子的化学性质,光谱能级和所形成配合物的化学结构和空间结构等方面综合考虑,提出协同发光机理.拟定出用于痕量铕和钐测定的薪的超高灵敏度分析方法. 相似文献
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本文研究了四溴荧光素(TBF)、罗丹明6G(R6G)等色染料离子对浮选光度法测定锗、铂和铁的方法。首先将被测金属离子形成的[MeLn(R6G)m](L:配位体,m、n为整数)有机溶剂浮选物,用碱解析并反萃于水相。而后加入与罗丹明6G等色的四溴荧光素溶液继续浮选,将形成的等色染料离子对R6GTBF浮选物溶解于丙酮。于530nm处测定吸光度值。由于2m个染料同时吸收同一波长的光,而提高了方法灵敏度。测定Ge、Pt和Fe的摩尔吸光系数均在105Lmol-1cm-1以上 相似文献
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电热石墨炉原子吸收法测定贵金属——(三)岩石矿物中超痕量金的测定 总被引:2,自引:1,他引:1
本文提出了用0.5ml N-正辛基苯胺-间二甲苯萃取测定岩石矿物中超痕量金的电热石墨炉原子吸收分析方法。对萃取剂的性能、萃取金的条件、其它离子的干扰情况以及在HGA-500型石墨炉中测定金的最佳条件进行了研究。样品用盐酸过氧化氢分解后,溶液进行萃取,有机相直接测定,大量的其它离子不干扰测定,为超痕量金的定量测试提供了简便、高灵敏的方法。本法绝对灵敏度为2.0pg/1%吸收,可检测0.00005g/T金。对含金量为0.0006g/T的矿样重复溶样测定11次,其相对标准偏差为4.4%。 相似文献
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等色染料离子对浮选光度法测定铂 总被引:5,自引:1,他引:4
提出了等色染料离子对浮选光度法、向罗丹明6G(R6G)和Pt(SnCl3)5^3-的异丙醚浮选物Pt(SnCl3(5(R6G)3中,加入PH=5.5的醋酸-醋酸铵缓冲溶液,使R6G离子进入水相,并向其中加入与R6G颜色相同的四溴荧光素(TBF)〉形成等色染料等离子对R6G,TBF,再被甲茉浮选,将浮选物溶于丙酮,于530nm处进行光度测定,由于6个染料分子(Pt:R6G:TBF)=(1:3:3)e 相似文献
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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. 相似文献
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本对四溴荧光素、丁基罗丹明B各自的吸光性质以及它们的形成的离子缔合物的吸光性质进行了研究。测得四溴荧光素与丁基罗丹明B在pH7时的缔合比为1:2。其Ksp=2.16×10^-18。缔合物的萃取率为83.2%。为进一步研究四溴荧光素、丁基罗丹明B的萃取光度分析奠定了理论基础。 相似文献
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固相分光光度法是一种简单、快速、灵敏的新型痕量分析方法。本文首次提出用聚酰胺做固体吸附剂,采用激发光谱进行测定,克服了固相分光光度法背景大的缺点,同时以大幅度提高灵敏度,这种方法有良好的加标回收率、精密度及较高的准确度。并可将固相分光光度法的应用由仅能分析痕量无机离子,推广到测定合成色素。 相似文献
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Biren Gohain Bornali Boruah Palash M. Saikia Robin K. Dutta 《Journal of Physical Organic Chemistry》2010,23(3):211-219
The premicellar and micelle formation behaviors of four cationic triphenylmethane dyes, viz, Pararosaniline (RN), Crystal violet (CV), Ethyl violet (EV), and Malachite green (MG), in aqueous anionic surfactant solutions of sodium dodecyl sulfate (SDS), sodium dodecyl benzene sulfonate (SDBS), and sodium dodecyl sulfonate (SDSN) have been studied by spectral and surface tension measurements. The study was carried out within a pH range where the dyes are stable in their quinoid forms. The dyes have been found to form dye–surfactant ion pairs (DSIPs) with the surfactants, at the surfactant concentrations well below their critical micelle concentration, CMC*. The DSIPs behave like nonionic surfactants and form an air–water interfacial monolayer. The DSIPs have a lower critical micelle concentration (CMCIP), greater efficiency, and lower effectiveness than the corresponding pure surfactants. As the surfactant concentration is increased below the CMC*, the DSIPs start forming micelles of their own where the dye gets protonated and exists as a protonated dye–surfactant ion pair (PDSIP) in the ion pair micelles. As the concentration of the surfactant exceeds the CMC* of the pure surfactant, the protonation reverses gradually with the dye remaining in the micelles in solubilized form and the DSIPs in the air–water interfacial monolayer are replaced by pure surfactants. The distorted helical isomeric form (isomer B) of the dyes is favored in the PDSIPs. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
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Eigen-Tamm模型认为水溶液中的离子对从单水分子桥链离子对到紧密离子对是离子对溶剂化平衡的动力学控制性步骤,两态之间自由能垒最高,相互转化速率最慢. 设计了两类带有单位电荷的离子对模型(2.0:x和x:2.0,固定离子对中的阳离子或阴离子的半径为2 ?,另一个为不同半径的阴阳离子),通过计算离子对不同距离的平均力势来获取自由能曲线,发现2.0:x系列离子对由于溶剂水的作用,从单水分子桥链离子对到紧密离子对转化的自由能垒有明显减低,并不是离子成对动力学平衡中的最慢步骤,与Eigen-Tamm 模型描述存在偏差. 相似文献
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Spectral and surface tension behavior of aqueous neutral red in the presence of sodium dodecyl sulfate (SDS), sodium dodecyl benzene sulfonate (SDBS) and sodium dodecyl sulfonate (SDSN) have been studied to understand the nature of the interactions in their submicellar concentration ranges. The variations in spectra and surface tension with variation in the concentrations of the surfactants suggest the formation of a 1:1 close-packed dye-surfactant ion pair, HNR+S− between the acid form, HNR+ of the dye and the surfactant anion at very low concentrations of the surfactant below critical micelle concentration (cmc) of the pure surfactant. The dye-surfactant ion pair behaves like a nonionic surfactant having higher efficiency and lower cmc than that of the corresponding pure anionic surfactant. The ion pairs are adsorbed on the air/water interface at very low concentrations of the surfactant. As the concentration of the surfactant increases and the ion pairs form micelles of their own, the dye in the ion pair is protonated to form H2NR2+S−. As the cmc of the pure surfactant is approached, the protonation equilibrium gradually reverses and pure surfactant ions gradually replace the ion pairs at the interface. Finally, a homogeneous monolayer of pure surfactant anions exists at the air/water interface and the dye remain solubilized in pure micelles above the cmc of the pure surfactant. The equilibrium constants, Kc for the close-packed protonated dye-surfactant ion pair (PDSIP) formation have been determined at varying pH. The submicellar interaction has been found to be stronger with SDS than SDBS. The plots of logarithm of Kc vs. pH have been found to be quite linear which consolidates the assumption of formation of the species, H2NR2+S−. The interaction is driven by enthalpy as well as entropy. 相似文献