有机阳离子[C18mim]＋在蒙脱土层间的物理化学吸附与聚集状态*

咪唑基离子液体(N鄄十八烷基鄄N忆鄄甲基溴化咪唑盐[C18mim]Br)中的[C18mim]+可以通过离子交换反应进入蒙脱土层间.本文用TGA、FTIR和XRD 研究了[C18mim]+在蒙脱土层间的物理和化学吸附及其聚集状态. 研究结果表明, 蒙脱土存在着饱和的化学吸附量, 其总吸附量随物理吸附量的增加而增加；随着[C18mim]+在蒙脱土层间吸附量的增加, 其聚集态结构的有序性增加, 并伴有分子链的构象变化,导致层间距的增加.     

微波衍生-离子对高效液相-磺化四苯基卟啉光度法同时测定痕量镍、铜、锰和锌

 用磺化四苯基卟啉 (TPPS4 )作柱前衍生试剂 ,在微波作用下进行衍生反应 ,研究了衍生和分离Ni2 + ,Mn2 + ,Zn2 + 和Cu2 + 的最佳条件。在 75 0W的微波作用下衍生反应 3min ,在C18柱上采用乙腈 水 (体积比为 2 2 5∶77 5 )体系作流动相 ,四乙基溴化铵 (TEABr)作离子对试剂 ,在 415nm处检测 ,建立了微波衍生 离子对高效液相快速分离、光度检测Ni2 + ,Mn2 + ,Zn2 + 和Cu2 + 的新方法。络合物和反应试剂在 15min内出峰完毕。Zn2 + ,Cu2 + ,Ni2 + 和Mn2 + 的检测限分别为 0 0 5 μg/L ,0 0 1μg/L ,0 10 μg/L和 0 40 μg/L。     

单取代二茂铁西佛碱型液晶化合物的合成及介晶性研究

报道了两个系列二茂铁衍生物，FcC_6H_4N＝CHC_6H_4OC_nH_(2n+1)（系列I） 和FcC_6H_4N＝CHC_6H_4O_2CC_6H_4OC_nH_(2n+1)（系列II）（Fc:ferrocenyl；n = 2，4，6，8，10，12，14，16），并通过DSC和热台偏光显微镜对其介晶性进行 了研究。系列I不具有介晶性，系列II呈较窄的液晶温度范围。其结果显示分子的 刚性部分长度对介晶性有重要影响。     

Determination of carbendazim,thiabendazole, and<Emphasis Type="Italic"> o-</Emphasis>phenylphenol residues in lemons by HPLC following sample clean-up by ion-pairing

An efficient analytical method is presented involving effective sample clean-up with solid-phase extraction and HPLC-UV analysis for the simultaneous determination of carbendazim, thiabendazole, and o-phenylphenol residues in lemons. Sample preparation involves extraction with acetonitrile acidified with trifluoroacetic acid and an ethyl acetate/petroleum ether mixture. Purification of the crude extract was carried out with liquid–liquid partitioning after addition of an aqueous ammonia solution. Final clean-up was performed on polymeric reversed-phase cartridges pretreated with sodium dodecyl sulfate. Chromatographic analysis was performed on a reversed-phase HPLC column isocratically eluted with an acetonitrile/water/ammonia mixture and UV detection at 254 nm. The chromatographic method is repeatable, reproducible, and sensitive. Fungicide recoveries from lemon samples fortified at levels of 5 and 1 mg kg^–1 were 81–85% for carbendazim, 96–98% for thiabendazole, and 81–106% for o-phenylphenol with coefficients of variation of 2.5–7.4%. Detection limits for carbendazim, thiabendazole, and o-phenylphenol in lemons were 0.21, 0.27, and 0.51 mg kg^–1, respectively.     

Determination of hydrolyzable tannins in the fruit of Terminalia chebula Retz. by high-performance liquid chromatography and capillary electrophoresis

A RP-HPLC method for determining fourteen components (gallic acid, chebulic acid, 1,6-di-O-galloyl-D-glucose, punicalagin, 3,4,6-tri-O-galloyl-D-glucose, casuarinin, chebulanin, corilagin, neochebulinic acid, terchebulin, ellagic acid, chebulagic acid, chebulinic acid, and 1,2,3,4,6-penta-O-galloyl-D-glucose) in the fruit of Terminalia chebula Retz. is described. The separation was achieved within 80 min using a binary gradient with mobile phases consisting of a pH 2.7 phosphoric acid solution and an 80% CH3CN solution. Capillary electrophoretic analyses were also attempted, and it was found that CZE (25 mM Na2B4O7, 5 mM NaH2PO4, pH 7.0) was an efficient method for the separation of gallotannins, while an MEKC method (25 mM Na2B4O7, 5 mM NaH2PO4, 20 mM SDS, pH 7.0, and 10% acetonitrile) provided a better separation for most of the tannins examined. The HPLC and CE methods developed were both successfully applied to the assay of tannins in commercial samples of Chebulae Fructus.     

改性离子液体中异丁烷与丁烯的烷基化反应

向由无水三氯化铝和盐酸三乙基胺合成的离子液体中溶入不同过渡金属（铜、铁、锌等）离子，考察它们对离子液体催化异丁烷与丁烯烷基化反应性能的影响。结果表明：过渡金属离子的加入能不同程度地影响离子液体的催化性能。溶入Cu2+和Cu+后，离子液体的催化性能有显著的改善，当Cu2+的摩尔加入量为三氯化铝的5%时，烷基化油收率达到丁烯体积的178%，对C8的选择性为75%，烷基化油辛烷值（RON）为92.2，并且离子液体可以重复使用。     

Accurate mass measurements by Fourier transform mass spectrometry in the study of advanced glycation end products/peptides

The Maillard reaction occurring between sugars and amino groups is important in living systems. When amino groups belonging to protein chains are involved, the Maillard reaction has been invoked as responsible for protein cross-linking and the production of 'toxic' compounds. The reaction leads to the production of a heterogeneous group of substances, usually called advanced glycation end products (AGEs). Classical analytical approaches, such as spectroscopic (ultraviolet, fluorescence) and mass spectrometric (matrix-assisted laser desorption/ionization, liquid chromatography/electrospray ionization mass spectrometry) methods, have shown that the digestion mixture is highly complex. However, there are clear differences between the digestion mixtures of glycated and unglycated human serum albumin (HSA). In the former case, possible glycated peptides belonging to the AGE peptide class may be identified. Tandem mass spectrometric experiments on selected species seemed to be promising as regards structural information, but it was thought of interest to undertake the present investigation, based on liquid chromatography/electrospray ionization Fourier transform mass spectrometry, in order to obtain definitive results on their elemental composition. Using this approach, about 20 glycated peptides were detected and their possible structures were postulated by examining the known sequence of HSA.     

FREE STANDING FILM OF POLYANILINE

A free standing film of polyaniline as large as 18 cm×18cm×0.002 cm can be obtained by evaporation of a solution of the chemically synthesized base in NMP. Its structure was examined by the elemental analysis, IR, U.V.-visible spectra, XPS, DSC, SEM and X-ray scattering and its conducting behavior as well as electrochemical properties were studied. Results show that the composition, structure of main chain, physical properties of the free standing film of polyanilme is similar to that of the powder. However, some differences in its electronic structure, conductivity at room temperature and potential of redox couple between the flee standing film and powder are observed, which may be due to cross-linking of the film of polyaniline.     

氨基酸柱前衍生化的3种新荧光试剂的光谱特性及高效液相色谱研究

合成了３种新的荧光标记试剂：吖啶－Ｎ－乙酰氯，咔唑－９－乙酰氯和咔唑－９－丙酰氯。它们的最大发射降激发波长分别为４３０ｎｍ，３６８ｎｍ，和３６５ｎｍ。３种衍生化试剂与氨基酸形成的衍生物在ｐＨ６．５的条件下结合梯度洗脱程序在Ｃ１８反相柱上对色谱条件进行了优化。     

On the plastic deformation of bulk syndiotactic polypropylene

 The plastic deformation of syndiotactic polypropylene (sPP) bulk samples has been investigated. A structural comparison of the initial states before and after plastic deformation by necking is carried out by X-ray diffraction observations. Independent of the initial states (amorphous, semi-crystalline with different crystal phases), only the planar all-trans crystal form of sPP is present in the deformed samples after necking. Form these results, molecular mechanisms of the plastic deformation in the neck zone of semi-crystalline polymers will be discussed. Received: 11 February 1997 Accepted: 15 August 1997