毛细管电泳的原理和应用(第六讲)CE在DNA、糖和离子分析中的应用

 简要介绍了ＣＥ在ＤＮＡ、糖和离子分析中的应用。ＤＮＡ分析包括分离原理、方法及检测手段，碱基、核苷和核苷酸分析，纯度检测和微量制备，ｓｓＤＮＡ和ｄｓＤＮＡ分析，基因突变检测及ＤＮＡ序列分析等。糖分析包括衍生化技术、检测方法、所用模式及糖复合物的分析等。离子分析包括阴离子分析原理、检测方法、影响因素、应用及阳离子分析等。     

Matrix assisted laser desorption/ionization-time of flight-mass spectrometry analysis of proteins detected by anti-phosphotyrosine antibody on two-dimensional-gels of fibrolast cell lysates after tumor necrosis factor-alpha stimulation

We describe efficient methods for using functional proteomics analysis to study signal transduction pathways in murine fibroblast L929 cells following stimulation with tumor necrosis factor (TNF)-alpha. After stimulation with TNF-alpha, cellular proteins of L929 cells were extracted with a lysis buffer containing 0.3% sodium dodecyl sulfate (SDS) for 10-30 min time intervals, and were separated by two-dimensional (2-D) electrophoresis followed by immunoblot analysis with anti-phosphotyrosine antibody and alkaline phosphatase-anti IgG antibody conjugate. To improve detection sensitivity by immunoblot analysis we used a chemifluorescent substrate for alkaline phosphatase. One hundred protein spots were detected in the TNF-alpha stimulated L929 cell extract by immunoblot analysis. The use of chemifluorescence allowed us to quantitate immunoblotted spots with fluoroscanner so that we were able to detect time-dependent changes of a number of immunoblotted spots. Protein spots on a silver-stained 2-D gel corresponding to those detected by immunoblot analysis were subjected to in-gel trypsin digestion- matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF)-mass spectrometry analysis, respectively. Twenty-one proteins detected by immunoblot analysis were identified by MS-Fit database search analysis. Among them, the proteins that show time-dependent changes in staining intensity include vimentin, tubulin beta-chain, eukaryotic translation initiation factor 1A, chromatin assembly factor 1 (P48 subunit), probable protein disulfide isomerase P5, and several other proteins. Vimentin and tubulin beta-chain have been reported to be phosphorylated at tyrosine residues and involved in the signal transduction pathway induced by TNF-alpha. However, the other proteins have no previously known function in the signal transduction pathway. Thus, the methods used in this study seem to be suitable for the identification of time-dependent changes in many proteins that are involved in signal transduction. Usefulness of the method for comprehensive analysis of the proteins involved in signal transduction pathway and the limitations of the method are discussed.     

Characterization of electrodeposited uranium films

Films containing uranium obtained by electrodeposition and used in alpha spectroscopic analysis were characterized by absorption spectroscopy, Raman spectroscopy, X-ray diffraction analysis and thermoanalysis. The electrodeposition method produced thin, adherent films with a yield near 100%. The analysis indicated that these films contained uranyl groups isolated or attached to other uranyl groups by oxygen bridges. Hydration water, hydroxyl groups linked by hydrogen bonds and ammonium radicals were also present. According to the X-ray diffraction analysis the films showed low crystallinity, characteristic to electrodeposited materials. The results of the thermogravimetric and differential thermal analysis did not correspond to any known pattern. This revised version was published online in July 2006 with corrections to the Cover Date.     

羟基中环二胺接枝壳聚糖的合成与表征

以具有环氧活性基的壳聚糖与3-羟基-1，5-二氮杂环庚烷或3-羟基1，5-二氮杂环辛烷反应，合成了两种含羟基的氮杂冠醚壳聚糖衍生物，其组成及结构经元素分析，IR，X-射线粉末衍射及^13C NMR等方法确证。     

An improvement of window factor analysis for resolution of noisy HPLC-DAD data

Window factor analysis (WFA) is a powerful tool in analyzing evolutionary process. However, it was found that window factor analysis is much sensitive to the noise involved in original data matrix. An error analysis was done with the fact that the concentration profiles resolved by the conventional window factor analysis are easily distorted by the noise reserved by the abstract factor analysis (AFA), and a modified algorithm for window factor analysis was proposed. Both simulated and experimental HPLC-DAD data were investigated by the conventional and the improved methods. Results show that the improved method can yield less noise-distorted concentration profiles than the conventional method, and the ability for resolution of noisy data sets can be greatly enhanced.     

Determination of vanadium in high grade carbons by radioanalytical methods

The present work deals with the determination of vanadium in high grade carbons by three radioanalytical methods, viz. thermal neutron activation analysis with an accelerator, thermal neutron activation analysis with a reactor and proton induced X-ray emission analysis with an accelerator. It is cleared from this study that thermal neutron activation with an accelerator is more convenient for the rapid and non-destructive analysis of ppm-level vanadium in bulk carbons than thermal neutron activation analysis with a reactor. Proton induced X-ray emission is less useful for the analysis of bulk samples.     

Application of an autoranging amplifier in the simultaneous determination of trace heavy metals by anodic stripping voltammetry

An autoranging amplifier with a gain of 1–1000 is described, together with its possible application in anodic stripping voltammetry. The performance of the amplifier is demonstrated by differential-pulse anodic stripping voltammetric analysis of stored sea-water, in the subtractive mode with two working electrodes. It is suggested that the autoranging amplifier could save considerable analysis time by eliminating the need for trial runs for gain adjustments and by relieving the operator from the need to change the recorder scale during the analysis.     

Effects of molecular structure parameters on ring-opening reaction of benzoxazines

A colorless monoclinic crystal of dichloro-benzoxazine was obtained and examined by single crystal X-ray diffraction analysis. At the same time, molecular modeling analysis of nine benzoxazine compounds with different substituting groups was performed. Both single crystal X-ray diffraction analysis and molecular modeling analysis provide a detailed picture of molecular structure on molecular level and show good consistence with each other. On the basis of structural analysis, the effects of molecular structure parameters on ring-opening polymerization of ben-zoxazines have been explored.     

Quantitative analysis of silicon-oxynitride films by EPMA

Thin films of silicon oxynitride with diverse compositions were prepared by de-magnetron sputtering of silicon, utilising oxygen and nitrogen gas flows and the sputtering power to vary the composition. In order to investigate the composition of these films, a method of analysis by electron probe micro analysis with energy dispersive detection was developed and the figures of merit were compared to the wavelength dispersive method used by other authors. The precision and repeatability of the results are evaluated and the accuracy is checked by comparison with Rutherford backscattering and nuclear reaction analysis. Energy dispersive X-ray spectrometry was proven to be applicable to analyse silicon oxynitride films of any composition yielding quantitative results for nitrogen and oxygen as well as silicon. Besides the good analytical performance, electron probe micro analysis with energy dispersive X-ray spectrometry has turned out to be a non-destructive, quick, easy to use and cost effective tool for the routine analysis of light elements in thin films.     

DNA片段的质谱试验中各相关因素的影响分析

利用DNA片断的质谱试验数据,通过分析各相关因素对质谱响应值的影响度,确定了灰色关联分析方法应用于本试验的可行性。并对灰色关联分析、相关分析和回归分析的结果做了比较。结果表明在DNA片段的质谱试验中,应用灰色关联分析能得到满意的分析结果,它克服了相关分析和回归分析等对数据量的要求,是在类似试验中最适合的分析方法。     

Direct enantiomeric separation of N-aminoethylamino acids: determination of the enantiomeric excess of chiral peptide nucleic acids (PNAs) by GC

Direct chiral separation of N-aminoethylamino acids has been performed for the first time by gas chromatographic (GC) analysis with a Chirasil-Val column, after derivatisation with trifluoroacetic anhydride in dichloromethane, which led to the corresponding piperazin-2-one derivatives, as identified by NMR and GC/MS analysis. The method was used for the analysis of the enantiomeric excess of chiral peptide nucleic acid (PNA) monomers and oligomers after hydrolysis with 6N HCl.     

Thermochemical Properties of Chemically Modified Zeolite

Zeolites chemically modified with 1, 4 or 6 M aqueous solutions of NaOH were studied by DTA, TG and ETA (emanation thermal analysis) in the temperature range 201–200°C. The structural changes in the modified zeolites at room temperature and in the modified zeolites annealed at 1000°C were studied by XRD analysis. Thermal analysis demonstrated dehydration, dehydroxylation, structural changes and a glass transition. A gradual loss in crystallinity of the chemically modified zeolites was also observed. XRD analysis revealed structural changes caused by chemical treatment and also by annealing.This revised version was published online in November 2005 with corrections to the Cover Date.     

镁同位素分析技术应用于葡萄酒辨别的探索研究

建立了阳离子树脂富集镁的方法.以1 mol/L HNO3为淋洗液、AG W50-X8阳离子树脂富集镁.方法回收率为(101.6±1.2)％.以H2 (2.1 mL/min)、He(7.0 mL/min)混合碰撞气消除12C12 C+,12C21H+等干扰的MC-ICP-MS分析方法.分析了40种葡萄酒中镁同位素组成,结果表明:不同产地葡萄酒中镁同位素组成差异明显;而且,来自同一产区不同葡萄园的葡萄酒中镁同位素组成也有显著差异.这表明镁同位素具有区分不同产地葡萄酒的能力,而且地理分辨率较高.对于部分镁同位素组成差异不明显的样品,结合元素分析手段,可以准确区分.     

速差动力学分析法同时测定铁、锌、铜

将化学计量学方法引入速差动力学分析方法中,在不预知动力学模型参数(速率常数)的情况下,用人工神经网络(ANN)依据铁、锌、铜的EGTA配合物与PAR置换反应的速度差异,对其三组分混合体系进行了同时测定.并对人工神经网络和偏最小二乘法对多波长、多时间点的三维量测模型的解析能力进行了比较,结果表明前者总体上优于后者.混合体系中铁、锌、铜测定的相对标准偏差分别为1.63%,3.29%和4.41%.本法还被用于饲料添加剂中微量元素的测定.     

Special Features of Oxidation of Hafnium Diboride Nanoparticles of Different Dispersity

Products of oxidation of HfB₂ particles with mean size 50–55 and 20–25 nm with air oxygen under polythermal and isothermal conditions have been studied by means of thermal analysis, scanning electron microscopy, X-ray energy-dispersive analysis, and elemental analysis. Rate constants of oxidation of the HfB₂ nanoparticles have been determined.     

分子三维投影法在苯酚类化合物构效关系研究中的应用

对苯酚类化合物进行三维投影得到了5个形状参数,将其与3个Am指数及8个量子化学参数相结合.由最佳变量子集回归法对变量进行了压缩与选择,运用多元回归分析和人工神经网络法分别构造了预测数学模型,得到了满意的结果.     

Study of the inclusion processes of styrene and alpha-methyl-styrene in beta-cyclodextrin

The inclusion complexes of styrene and alpha-methyl-styrene with beta-cyclodextrin (beta-CD) were investigated by using [1H] NMR titration in solution and X-ray diffraction (XRD) analysis, thermo-gravimetric analysis (TGA), elemental analysis (EA) in the solid state. The inclusion process has been studied by using PM3 quantum-mechanical semi-empirical method. The calculated results are in agreed with the experimental data. All results show that alpha-methyl-styrene has stronger interaction with beta-cyclodextrin than styrene does, so the complex of beta-CD-alpha-methyl-styrene is more stable.     

Determination of wheat quality by mass spectrometry and multivariate data analysis

Multivariate analysis has been applied as support to proteome analysis in order to implement an easier and faster way of data handling based on separation by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry. The characterisation phase in proteome analysis by means of simple visual inspection is a demanding process and also insecure because subjectivity is the controlling element. Multivariate analysis offers, to a considerable extent, objectivity and must therefore be regarded as a neutral way to evaluate results obtained by proteome analysis.Proteome analysis of storage proteins from the wheat gluten complex based on two-dimensional electrophoresis and analysis of the N-terminal sequence has revealed a protein homologous to gamma-gliadins, tentatively associated with quality and within the molecular weight range 27-35 kDa. Further examinations of gliadin data based on mass spectrometry revealed that quality among wheat varieties could be determined by means of principal component analysis. Further examinations by interval partial least squares made it possible to encircle an overall optimal molecular weight interval from 31.5 to 33.7 kDa. The use of multivariate analysis on data from mass spectrometry has thus shown to be a promising technique to minimize the number of two-dimensional gels within the field of proteome analysis.     

Electroanalytical study of fluvoxamine

Fluvoxamine (FVX) can be reduced at a mercury-drop electrode, with a maximum peak current intensity being obtained at a potential of –0.7 V vs. Ag/AgCl, in an aqueous electrolyte solution of pH 2. The compound was determined in a pharmaceutical product and in spiked human serum by square-wave adsorptive-stripping voltammetry (SWAdSV) after accumulation at the electrode surface, under batch conditions. Because the presence of dissolved oxygen did not interfere significantly with the analysis, it was also possible to determine FVX in the pharmaceutical product by use of a flow-injection analysis (FIA) system with SWAdSV detection. The methods developed were validated and successfully applied to the quantification of FVX in a pharmaceutical product. Recoveries between 76 and 89% were obtained in serum analysis. The FIA–SWAdSV method enabled analysis of up to 120 samples per hour at reduced cost, implying the possibility of competing with the chromatographic methods usually used for this analysis.     

Evaluation of the degree of hydration of synthetic alites by quantitative differential thermal analysis

The degree of hydration of synthetic alites has been determined by quantitative differential thermal analysis, using strong signals related to the polymorphic transformations of alites. The conditions suitable for noting the various reference signals, obtained with maximum apparatus sensibility, have been described and the data derived from differential thermal test with those obtained by analysis of the liquid phase in contact with the hydrating solid are correlated.