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931.
932.
A series of novel hemicyanine dye-β-cyclodextrin compounds: mono-6-deoxy-β-cyclodextrin-6-[p-(p-substituted styryl)pyridium] p-totylfulfonates were synthesized by the condensation of mono-6-deoxy-β- cyclodextrin-6-(p-methyl pyridinium) p-toluenesulfonate with (un)substituted benzaldehydes. Their structures were established by 1^H NMR, IR, UV-Vis and elemental analysis. The absorption and fluorescence properties of the novel compounds were measured in solution and the photostability of a selected hemicyanine dye-β-cyclodextrin compound was also investigated. 相似文献
933.
Studies of the electrochemical behavior of epinephrine at a homocysteine self-assembled electrode 总被引:6,自引:0,他引:6
The self-assembled electrode with the homocysteine monolayer (Hcy/Au) has been characterized by infrared spectroscopy and ac impedance spectroscopy in electrolyte. The Hcy/Au electrode is demonstrated to promote the electrochemical response of epinephrine (E) by cyclic voltammetry. A pair of well-defined redox waves was obtained and the calculated standard rate constant (ks) is 2.1×10−2 cm s−1 at the self-assembled electrode. The reduction peak of E can be used to determine the concentration of E in presence of ascorbic acid (AA) owing to the Hcy/Au also promoting the electrochemical oxidation of AA. 相似文献
934.
The reaction of PdCl2 in water with 2-hydroxypropane-1, 3-diaminetetraacetic acid (HPDTA) gave the complex Pd (C11H16N2O9)·1. 5H2O, which was characterized by elemental analysis, IR, NMR and single-crystal X-ray diffraction. The spectroscopic and X-ray diffraction data show that Pd ( Ⅱ ) is coordinated by two nitrogen atoms and two car-boxylic oxygen atoms. The complex crystallizes in monoclinic space group Pc with a = 1. 1240(2), b=1. 1183(2), c=1. 2597(3) nm, β=96. 33(2)°V=1. 5737(6) nm3, Z = 4, R= 0.038. The structure contains two crystallographically independent molecules which have slightly different orientations and are connected by hydrogen bonds. 相似文献
935.
研究了用Cu2 -1-(2-吡啶偶氮)-2-萘酚(PAN)分光光度法测定人体血清中痕量铜的最佳条件。在HCl-KCl溶液介质中,十二烷基苯磺酸钠存在下,其表观摩尔吸光系数为1.42×104 L.mol-1.cm-1,Cu2 含量在0~2μg/mL范围服从比尔定律,检测限为0.5μg/dm3。操作简便、快速,该法可用于人体血清中痕量铜的测定。 相似文献
936.
Ying WANG Su Juan WANG Shun Yan MO Shuai LI Yong Chun YANG Jian Gong SHI Institute of Materia Medica Chinese Academy of Medical Sciences Peking Union Medical College 《中国化学快报》2006,(4)
A new abietane diterpene 12-hydroxy-7-oxo-5, 8, 11, 13-tetraene-18, 6-abietanolide, together with a new natural sterol stigmasta-7, 22-diene-3β, 5α, 6α-triol have been isolated from the fruiting body of the fungus Phellinus igniarius. Their structures were elucidated by spectroscopic methods including 2D NMR techniques. 相似文献
937.
MCM-41介孔分子筛共价键联钴酞菁的制备,表征及性质 总被引:1,自引:0,他引:1
采用两种方法将钴酞菁配合物共价联接到介孔分子筛MCM-41的表面:(1) 在MCM-41表面联接含伯胺的有机侧链;(2) 是在MCM-41表面联接含仲胺的有机侧链。含氯磺酸基的钴酞菁与胺反应形成磺酰胺。对得到的主客体化合物用多种物化手段和催化反应进行了表征。结果表明,钴酞菁以单体形式固定在介孔分子筛MCM-41的孔道壁上,在反应条件下固载后的钴酞菁具有高催化活性,同时表现出良好的稳定性,多次重复使用活性没有明显的改变。 相似文献
938.
Wei DENG Wei Ping YANG Zhu Jun ZHANG* Xiao Rong LI College of Chemistry Materials Science Shaanxi Normal University Xi抋n 《中国化学快报》2003,14(3)
Chromiumexistsindifferentoxidationstatesingroundwater,industrialwastewater,seawater,andsoilofourenvironment1,2.Chromium(III)isanessentialtraceelementforhumans,requiredforthemaintenanceofnormalglucose,cholesterol,andfattyacidmetabolism.Ontheotherhand,watersolublechromium(VI),intheformCr2O72-orCrO42-,ishighlyirritatingandtoxictohumansandanimals3.Itsacutetoxiceffectsincludeanimmediatecardiovascularshockandlatereffectsonkidney,liver,andblood-formingorgans.Therefore,itisnecessaryforriskassessme… 相似文献
939.
Three new serratane triterpenoids, (3α,14α,15α,21α)‐3,14,15,21,29‐pentahydroxyserratan‐24‐oic acid ( 1 ), (3α,21β)‐serrat‐14‐ene‐3,21,24,30‐tetraol ( 2 ), and (3α,21α)‐serrat‐14‐ene‐3,21,24,29‐tetraol ( 3 ), were isolated from Phlegmariurus squarrosus, together with eight known compounds. Their chemical structures were elucidated on the basis of in‐depth spectroscopic analyses. 相似文献
940.
Microscale sample deposition onto hydrophobic target plates for trace level detection of neuropeptides in brain tissue by MALDI-MS 总被引:1,自引:0,他引:1
Wei H Dean SL Parkin MC Nolkrantz K O'Callaghan JP Kennedy RT 《Journal of mass spectrometry : JMS》2005,40(10):1338-1346
A sample preparation method that combines a modified target plate with a nanoscale reversed-phase column (nanocolumn) was developed for detection of neuropeptides by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). A gold-coated MALDI plate was modified with an octadecanethiol (ODT) self-assembled monolayer to create a hydrophobic surface that could concentrate peptide samples into a approximately 200-500-microm diameter spot. The spot sizes generated were comparable to those obtained for a substrate patterned with 200-microm hydrophilic spots on a hydrophobic substrate. The sample spots on the ODT-coated plate were 100-fold smaller than those formed on an unmodified gold plate with a 1-microl sample and generated 10 to 50 times higher mass sensitivity for peptide standards by MALDI-TOF MS. When the sample was deposited on an ODT-modified plate from a nanocolumn, the detection limit for peptides was as low as 20 pM for 5-microl samples corresponding to 80 amol deposited. This technique was used to analyze extracts of microwave-fixed tissue from rat brain striatum. Ninety-eight putative peptides were detected including several that had masses matching neuropeptides expected in this brain region such as substance P, rimorphin, and neurotensin. Twenty-three peptides had masses that matched peaks detected by capillary liquid chromatography with electrospray ionization MS. 相似文献