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碱土金属与多卤代偶氮氯膦类试剂显色反应的研究 总被引:1,自引:0,他引:1
近年来合成的多卤代偶氮氯膦类试剂有希望成为一类有效的碱土金属显色剂。本文研究了此类试剂与钙、锶、钡所生成配合物的吸收光谱、显色酸度、选择性、灵敏度和配合物的组成,以及试剂结构与性能的关系等。说明了不同取代助色基对显色反应各方面的影响。通过研究筛选出了较好的碱土显色剂,这几种试剂的结构如下: 相似文献
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本研究了钍对马尿酸偶氮氯膦(pHA-CPA)络合物的形成条件及其在光度分析中的应用。实验证明。钍与pHA-CPA形成络合比为1∶3的蓝紫色络合物,λmax=680nm,ε=9.63×10^4.该方法用于测定稀土矿中微量钍,结果良好。 相似文献
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《Analytical letters》2012,45(4):799-809
ABSTRACT A novel spectrophotometric method based on amino G acid chlorophosphonazo (AGCPA) has been developed for measuring calcium in human serum and cerebrospinal fluids. The effects of experimental factors including pH, reagent concentrations, and interfering species on calcium determinations were investigated. In a neutral reaction media of pH 7.0, AGCPA reacts rapidly with calcium to form a stable and greenish blue complex, whose absorption maximum is at 670 nm. The molar absorptivity (?) of the complex is 7.2x104 1 mol?1cm?1, and the molar ratio of calcium to AGCPA in the complex is found to be 1:2. Beer's law is obeyed over the range 0.02-0.8 μg ml?1 of calcium. No interferences were observed from the commonly coexisting species present in serum and cerebrospinal fluids. Compared to the reported and currently often used methods based on o-cresolphthalein complexone, arsenazo III and methylthymol blue, the proposed method in this work provides better analytical characteristics such as high sensitivity, good selectivity and neutral reaction media. In addition, the present method is simple and can be applied to the direct determination of calcium in human serum and cerebrospinal fluid samples with satisfactory results. 相似文献
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IntroductionThedeterminationofproteinsisimportantinbiochemicalstudy ,clinicaltreatmentandfoodanalysis .Asitisknown ,thecommonmethodsusedtodeterminetheproteinquantita tivelyatpresentarespectrophotometryandfluorospec trophotometry.1Recently ,resonanceRayleig… 相似文献
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Martin Sahlberg Yvonne Andersson 《Acta Crystallographica. Section C, Structural Chemistry》2009,65(3):i7-i8
Scandium magnesium gallide, Sc2MgGa2, and yttrium magnesium gallide, Y2MgGa2, were synthesized from the corresponding elements by heating under an argon atmosphere in an induction furnace. These intermetallic compounds crystallize in the tetragonal Mo2FeB2‐type structure. All three crystallographically unique atoms occupy special positions and the site symmetries of (Sc/Y, Ga) and Mg are m2m and 4/m, respectively. The coordinations around Sc/Y, Mg and Ga are pentagonal (Sc/Y), tetragonal (Mg) and triangular (Ga) prisms, with four (Mg) or three (Ga) additional capping atoms leading to the coordination numbers [10], [8+4] and [6+3], respectively. The crystal structure of Sc2MgGa2 was determined from single‐crystal diffraction intensities and the isostructural Y2MgGa2 was identified from powder diffraction data. 相似文献