On-line Separation and Detection of Peptides by Capillary Electrophoresis / Electrospray FT-ICR-MS

Recently, capillary electrophoresis/electrospray ionization mass spectrometry (CE/ESI- MS) has been rapidly developed as a powerful analytical tool for charged species ranged from small molecules such as carboxylic acids1, phenolic compounds2, metal species3, tetramines4, herbicides5, drugs and drug metabolites6 to peptides and proteins7, 8. The ESI mode has proven to be sensitive, versatile and relatively easy to use in combination with CE. CE confers rapid analysis and efficient separ…     

Detection of paracetamol by capillary electrophoresis with chemiluminescence detection

Indirect detection of paracetamol was accomplished using a capillary electrophoresis-chemiluminescence (CE-CL) detection system, which was based on its inhibitory effect on a luminol-potassium hexacyanoferrate(III) (K₃[Fe(CN)₆]) CL reaction. Paracetamol migrated in the separation capillary, where it mixed with luminol included in the running buffer. The separation capillary outlet was inserted into the reaction capillary to reach the detection window. A four-way plexiglass joint held the separation capillary and the reaction capillary in place. K₃[Fe(CN)₆] solution was siphoned into a tee and flowed down to the detection window. CL was observed at the tip of the separation capillary outlet. The CL reaction of K₃[Fe(CN)₆] oxidized luminol was employed to provide the high and constant background. Since paracetamol inhibits the CL reaction, an inverted paracetamol peak can be detected, and the degree of CL suppression is proportional to the paracetamol concentration. Maximum CL signal was observed with an electrophoretic buffer of 30 mM sodium borate (pH 9.4) containing 0.5 mM luminol and an oxidizer solution of 0.8 mM K₃[Fe(CN)₆] in 100 mM NaOH solution. Under the optimal conditions, a linear range from 6.6 × 10⁻¹⁰ to 6.6 × 10⁻⁸ M (r = 0.9999), and a detection limit of 5.6 × 10⁻¹⁰ M (signal-to-noise ratio = 3) for paracetamol were achieved. The relative standard deviation (R.S.D.) of the peak area for 5.0 × 10⁻⁹ M of paracetamol (n = 11) was 2.9%. The applicability of the method for the analysis of pharmaceutical and biological samples was examined.     

Mixed solutions of an associating polymer with a cleavable surfactant

Mixtures of hydrophobically modified hydroxyethyl cellulose (HMHEC) and alkali-sensitive cleavable betaine ester surfactants have been studied by viscometry, 1H NMR, absorbance measurements, and birefringence determinations. Before the hydrolysis, the surfactants behaved as conventional nondegradable surfactants in terms of the effect on the viscosity of increasing surfactant concentration. As the surfactants were hydrolyzed, systems with time-dependent viscosity were obtained. The viscosity either decreased monotonically or went through a maximum as a function of time, depending on the initial surfactant concentration. Different surfactant chain lengths gave rise to different viscosity profiles. The rate of hydrolysis, and thus the time-dependency of the surfactant concentration, could be controlled by changing the pH of the solution.     

咪唑-金属配合物的合成、性质及其与DNA的作用机理

Three hexakis（imidazole）metallo complexes of Co, Cd and Ni were synthesized and spectroscopically characterized. The crystal and molecular structures have been determined by X-ray crystallography analysis. The metal ions have an octahedral geometry with the MN6 chromophore. The electrochemical experimental results indicate that both [Co（Im）6]C12·2HCl·2H2O （1） and [Ni（Im）6]C12·4H2O （3） [Im=imidazole] could interact with DNA mainly by intercalation.     

Uniform hierarchical silica film with perpendicular macroporous channels and accessible ordered mesopores for biomolecule separation

Herein, we demonstrate that silica films with perpendicular macroporous channels and accessible ordered mesopores can be conveniently prepared. The hierarchical macroporous–mesoporous silica films are synthesized by using zinc oxide nanorod array as macroporous template and CTAB surfactant as mesoporous template. In basic surfactant-containing solution, ordered mesoporous silica shells homogeneously grow on the zinc oxide nanorod array. The growth of the mesostructures do not require any chemical modification for the zinc oxide nanorod, which opens a new way for preparing hierarchical silica films with perpendicular mesochannels. The prepared hierarchical macroporous–mesoporous silica films possess a uniform thickness of 2 mm, large perpendicular macropores with a length of 1.8 mm and a width of 80 nm, and accessible ordered mesopores. Separation experiment demonstrates that this macroporous–mesoporous film can effectively separate biomolecules with different sizes.     

Construction and analytical applications of a liquid-state iodide-selective electrode with a metal complex as exchanging site

Summary A new type of liquid-membrane iodide-selective electrode based on a 0.001M solution of tris(l,10-phenanthroline)ruthenium(II) iodide in 1,2-dichlorobenzene is described. The electrode has Nernstian behaviour down to 7×1O^–6M iodide. It has good selectivity towards halide (k _{I, Cl}=5.3×10^–6 andk _{I, Br}=1.6×10^–4) and other inorganic ions, and a linear response to iodide at pH-values from 3 to 9. It can be used either in direct iodide analyses or in potentiometric titrations. Titration of halide mixtures or of pseudohalides is also possible. The method has been used for determining the free formaldehyde present in dispersing agents.

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Herstellung und analytische Anwendung einer jodid-spezifischen Elektrode mit Flüssigmembran mit einem Metallkomplex als Austauscher

Zusammenfassung Eine neue jodid-spezifische Flüssig-Membran-Elektrode auf der Basis einer 0,001 M Lösung von Tris(1,10-phenanthrolin)-Ruthenium(II)-jodid in 1,2-Dichlorbenzol wurde beschrieben. Sie zeigt Nernstsches Verhalten bis zu 7×10^–8 M Jodid, gute Selektivität gegenüber Halogeniden (k _{I, Cl}=5,3× 10^–6 undk _{I, Br}=1,6×10^–4) und anderen anorganischen Ionen und ein lineares Verhalten gegenüber Jodid bei pH 3–9. Die Elektrode läßt sich für direkte Jodidbestimmungen oder für potentiometrische Titrationen verwenden. Die Titration von Halogenidgemischen oder Pseudohalogeniden ist ebenfalls möglich. Das Verfahren wurde zur Bestimmung von freiem Formaldehyd in Dispersionsmitteln verwendet.

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Presented at the 8th International Microchemical Symposium, Graz, August 25–30, 1980.     

雪松烯的光氧化反应研究

以次甲基兰为光敏剂, 甲醇为溶剂, 用通氧光照产生的单重态氧与雪松烯反应,产物只有一种。用元素分析、红外光谱。核磁共振谱、质谱以及高压液相色谱等方法测定了产物的分子结构。并讨论了光氧化反应的动力学控制和立体效应。     

POLYBINAPHTHYLS INCORPORATING (R)-2,2''''-BINAPHTHO-20-CROWN-6 AND NAPHTHYL MOITIES

Chiral polymer was synthesized by the polymerization of (R)-6,6'-bistributylstannyl-2,2'-binaphtho-20-crown-6 (M-1) with 1,4-dibromo-2,3-bisbutoxy-naphthyl (M-2) by Pd(PPh3)4 catalyzed Stille coupling reaction. Both monomer and polymer were analyzed by NMR, MS, FT-IR, UV, polarimetry, DSC-TGA, CD, fluorescent spectroscopy and GPC. The major difference between monomer and polymer is that a long wavelength Cotton Effect was observed for the polymer due to its more extended conjugation in the repeating unit and a highly rigid backbone in the polymer chain. Polymer has strong blue fluorescence due to the efficient energy migration from the extended n-electronic structure of the repeating unit of the polymer to the chiral binaphthyl core and is expected to have potential application in the materials of fluorescent sensors and chiral chromatographic packing for resolution of racemic amino acid.     

Self-assembly in dinuclear, cyclic homotetranuclear and cyclic heterotetranuclear complexes with a picolylhydrazone ligand

Reactions among Cu(ClO₄)₂ · 6H₂O, Cu(acac)₂/VO(acac)₂ and 3-methoxysalicylaldehyde Picoloylhydrazone in different solvents give three complexes, [Cu₂L(acac)(H₂O)₂]ClO₄ (1), [Cu₄L₂(acac)₂(py)₂](ClO₄)₂ (2) and (VO₂)₂L₂Cu₂(acac)₂ (3) (acac = acetyl acetonate and py = pyridine). There is an extended 2D structure in complex 1 constructed by hydrogen bonds between the binuclear complex cation and the ClO₄⁻ anion, and an extended 1D structure in complex 2 constructed by weak ππ stacking interactions between neighboring cyclic tetranuclear complex molecules. Complex 3 is the first oxovanadium–copper complex with a bridging oxo oxygen atom between the V atom and the Cu atom. The solid-state photoluminescent properties of the three title complexes have been studied. There is an antiferromagnetic interaction in 1.     

聚联苯酰亚胺/聚硫醚酰亚胺共混体系的相容性

<正> 聚酰亚胺是一种性能极其优异的高性能树脂,它在许多高技术领域有着极其重要的应用价值。在80年代以前,人们工作的重点是合成出一系列分子结构不同的聚酰亚胺,研究分子结构与性能间的关系,开发聚酰亚胺新品种。自80年代后期,有关高性能树脂聚酰亚胺共混物的研究日益引起人们的关注,其中有关不同分子结构的聚酰亚胺/聚酰亚胺共