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排序方式: 共有711条查询结果,搜索用时 15 毫秒
1.
毛细管电泳安培检测扑热息痛及其水解物   总被引:1,自引:0,他引:1  
刘峻  周伟红 《分析化学》1995,23(11):1256-1260
研究了各种电化学预处理条件下碳纤维电极对扑热息痛及水解物的电化学行为。确定该体系最佳预处理条件为0.2V电位下阳极化1min,再于-2.0V下阴极化10s。预处理后的碳纤维伏安响应得到明显提高。运用最佳条件并在支持电解中加入添加剂后,扑热息痛及其水解物在毛细管电泳上获得很好的分离和检测。其中扑热息痛的检测下限为2.78pg;对氨基酚为1.84pg。  相似文献   
2.
冠醚型电极对局部麻醉药响应功能的研究   总被引:3,自引:0,他引:3  
用二苯并24-冠-8作为活性物质、邻苯二甲酸二(2-乙基)己酯为增塑剂制得PVC膜电极。电极对局麻药丁卡因、普鲁卡因和利多卡因具有能斯特响应,用于局麻药针剂的测定取得满意的结果。  相似文献   
3.
三(2-苯并咪唑亚甲基)胺硝酸镍(Ⅱ)配合物的合成及结构   总被引:5,自引:0,他引:5  
三(2-苯并咪唑亚甲基)胺简称NTB与Ni(Ⅱ)的硝酸盐形成配合物C28H35N9O9S2Ni。本文报道其合成,红外光谱及晶体结构。该化合物为三斜晶系,空间P1↑-,a=9.650(3),b=12.716(2),c=14.436A,α=11.46(2),β=91.66(3),γ=97.55(2)°,V=1718(2)A^3,Z=2,F(000)=793,Dc=1.48g/cm^3,Mr=764.1  相似文献   
4.
A new method for the study of ternary surface complexes at liquid-solid interface, theE(%) -pH curve method, was proposed. Four types ofE(%)-pH curves, namely, phenomenon of left-right shifts of S-shaped curve, V-shaped curve, monodirection shift curve and X-shaped curve, were discovered. Correspondingly, apart from type (I) ternary surface complex and type (II) ternary surface complex , a new type of ternary surface complex was discovered. Project supported by the National Natural Science Foundation of China and the Fund of Doctoral Degree’s Spot.  相似文献   
5.
甲基丙烯酸三苯墓甲酯和甲基丙烯酸酯类的共聚物在溶液中的螺旋诱导和解旋作用陈传福,刘卫宏,陈永明,任长玉,习复(中国科学院化学研究所北京100080)关键词甲基丙烯酸三苯基甲酯,甲基丙烯酸甲酯,光学活性,螺旋诱导,解旋在手性阴离子复合引发剂存在下,甲基...  相似文献   
6.
Nanoparticles for the extraction of peptides and subsequent analysis using atmospheric pressure matrix-assisted laser desorption/ionization (APMALDI) have been evaluated. The atmospheric pressure source allows for particles to be directly introduced in the liquid matrix, minimizing sample loss and analysis time. Described in this work are two sample preparation procedures for liquid APMALDI analysis: a C18 functionalized silica nanoparticle for hydrophobic extractions, and an aptamer functionalized magnetite core nanoparticle for rapid, affinity extractions. The C18 particles provide a non-selective support for rapid profiling applications, while the aptamer particles are directed towards reducing the complexity in biological samples. The aptamer functionalized particles provide a more selective analyte-nanoparticle interaction whereby the tertiary structure of the analyte becomes more critical to the extraction. In both cases, the liquid APMALDI matrix provides a support for ionization, and acts as the releasing agent for the analyte-particle interaction. Additionally, analyte enrichment was possible due to the large surface-to-volume ratio of the particles. The experiments conducted with functionalized nanoparticles, in an atmospheric pressure liquid matrix, present a basis for further methodologies and utilities of silica nanoparticles to be developed.  相似文献   
7.
三羟基苯及其衍生物是一类重要配体,如3,4,5-三羟基苯甲酸(GA)与铀、钍及稀土生成沉淀,并可用于铀、钍、稀土的连续测定。我们在研究用GA离铀、钍、稀土时,GA与铀生成1种棕色配合物,早期曾用于铀的比色测定,它可能是一种单核与多核配合物的混合物,但对这类化合物与铀的配位反应迄今来作过详细研究。本文用光度法研究了GA、连苯三酚(PGA)、3,4,5-三羟基苯甲酸丙酯(PGE)与3,4,5-三甲氧基苯甲酸(TMBA)与铀(Ⅵ)的配位反应,研究了配合物的组成及其反应机理,测定了部分配合物的稳定常数。  相似文献   
8.
A simple and efficient approach for the rapid isolation of plasmid DNA from crude cell lysates has been described. The approach took advantage of the amino-modified silica coated magnetic nanoparticles (ASMNPs) with positive zeta potential at neutral pH and superparamagnetism under the external magnetic fields. As a demonstration, the pEGFP-N3 plasmid has been concentrated and isolated from the E. coli DH5α transformed with pEGFP-N3 plasmid through electrostatic binding between the positive charge of the amino group of ASMNPs and the negative charge of the phosphate groups of the plasmid DNA. Then the pEGFP-N3 plasmid has been released easily and quickly from the pEGFP-N3 plasmid-ASMNPs complexes with 3 M NaCl. The entire procedure could be carried out by the aid of external magnetic fields in 15 min and eliminate the need of phenol, cesium chloride gradients or other noxious reagents and complexes operation. Moreover, the pEGFP-N3 plasmid obtained by this approach retains biological activity that can be suitable for restriction enzyme digestion and cells transfection with expression of green fluorescence protein.  相似文献   
9.
Supercritical carbon dioxide is an efficient solvent for adsorptive separations because it can potentially be used as both the carrier solvent for adsorption and the desorbent for regeneration. Recent results have demonstrated an anomalous peak or "hump" in the adsorption isotherm near the bulk critical point when the adsorption isotherm is plotted as a function of bulk density. This work presents new data for the adsorption and desorption of carbon dioxide in the near-critical region on a crystalline, well-structured adsorbent (NaY zeolite). The results indicate a strong affinity for CO(2) as well as a significant hump near the critical point. The lattice model previously developed by Aranovich and Donohue is applied to analyze the adsorption.  相似文献   
10.
Du Y  Yan J  Zhou W  Yang X  Wang E 《Electrophoresis》2004,25(21-22):3853-3859
We developed an electrochemical detector on a hybrid chip for the determination of glucose in human plasma. The microchip system described in this paper consists of a poly(dimethylsiloxane) (PDMS) layer containing separation and injection channels and an electrode plate. The copper microelectrode is fabricated by selective electroless deposition. The fabrication of the decoupler is performed by platinum electrochemical deposition on the metal film formed by electroless deposition. Factors influencing the performance, including detection potential, separation field strength, and buffer concentration, were studied. The electrodes exhibited good stability and durability in the analytical procedures. Under optimized detection conditions, glucose responded linearly from 10 microM to 1 mM. Finally, glucose in human plasma from three healthy individuals and two diabetics was successfully determined, giving a good prospect for a new clinical diagnostic instrument.  相似文献   
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