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。     

Gas chromatographic analysis of organic solvent mixtures on capillary columns of different polarity

Summary A gas chromatographic method for the analysis of organic solvents in chemical products is described. The analysis is performed by the use of a polar column, Supelcowax 10, and a non-polar column CP-Sil-5CB. Samples containing a non-volatile matrix or water were analysed by headspace analysis. The identification of the solvents in a sample, based on GC retention times on one column, is confirmed by GC of the sample on the second column. The method has been found to be suitable for the routine analysis of solvent mixtures.     

Determination of arsenic in germanium by the combination of isotope dilution and activation analysis

The determination of arsenic by activation analysis in germanium may be disturbed by arsenic isotopes formed in the irradiation of the germanium matrix itself. The isotopic dilution technique will eliminate such interferences, but it requires weighing of very small masses of arsenic, after appropriate chemical separation. This weighing procedure can be avoided if the mass of the recovered arsenic is determined by activation analysis. In order to apply such a procedure, a known amount of arsenic labelled with⁷⁶As, whose specific activity is also known, is added to the germanium sample to be analysed. The sample is processed, the arsenic separated, and the chemical yield established. The recovered mass of arsenic is then determined by activation analysis applying the classical isotopic dilution analysis formula. The accuracy precision and linearity of the method are discussed.     

The determination of Eu and Sm by application of X-ray spectrometry to isotope-source activation analysis

The use, for analysis, of K X-rays proceeding from metastable and beta-emitting radionuclides—produced by neutron activation—is an undeveloped aspect of activation analysis. Consequently, this study examines the feasibility of applying X-ray spectrometry to isotope source activation analysis and in particular the determination of Sm and Eu at low levels is described. Generally speaking, the sensitivity is seriously restricted by the thermal neutron flux of the source but in certain specific cases the analysis is favoured by the nuclear properties of the elements concerned. Therefore, the selection of elements was based largely on their demand for analysis and their ability to produce a practicable yield. Optimum signalto-noise ratios were attained by employing a detector that was particularly sensitive at energies below 150 keV. Analytical conditions are demonstrated for the elements of interest over a wide range of concentrations in small samples, and ultimately the applicability of the method was tested by the analysis of a typical monazite sample. The analytical potential of the method is thoroughly appraised and possible practical applications are discussed.     

小波包分析用于重叠分析化学信号的处理

对小波包分析的算法进行了改进,并将此算法成功地应用于多组分重叠色谱信号的解析.结果表明,本文提出的算法解决了MRSD算法的不足,更适合处理分析化学信号,用于重叠信号的解析时不需重构(逆变换),简化了数据处理步骤,加快了数据解析速度,具有较强的解析能力.对于重叠色谱信号的解析,小波包分析比小波分析具有更强的解析能力.     

Determination of nanoparticle sizes by X-ray diffraction

Different procedures for analysis of particle sizes by the X-ray diffraction method are compared by the example of nanoparticles of nickel and iron(3+) oxide (Fe₂O₃). A modified Warren-Averbach method is proposed for the analysis of the X-ray diffraction line profile based on the approximation by the Voigt function, which yields stable solutions, and the efficiency of the method is shown. The analysis within the frame-work of the Warren-Averbach method makes it possible to restore the distribution function of nanoparticles (crystallites) over true diameters, which satisfactorily correlates with electron microscopy data. The applicability of the Warren-Averbach method to the estimation of crystallite sizes by the analysis of a single diffraction line is substantiated. The range of the applicability of the Scherrer, Williamson-Hall, Warren-Averbach, and modified Warren-Averbach methods to the substructure analysis by the X-ray diffraction is determined as depending on the method of nanostructure formation.     

Optimization of precision and throughput in micellar elektrokinetic chromatography

Summary The influences of micelle concentration, applied voltage and temperature on the precision and throughput of analysis are studied. The precision is the Shannon mutual information and the throughput is the transmission speed of the information (=information divided by analysis time). The dependence of the precision and throughput on the peak shape, resolution Rs and run time is examined in various operating conditions. The most precise analysis (indicated by the maximum of the information) and the highest throughput analysis (the maximum of the transmission speed) are selected and their analytical importance is discussed.     

冬小麦麸皮抗冻蛋白一级结构的研究

冬小麦麸皮抗冻蛋白(TaAFP)的一级结构是研究其高级结构和功能的基础.本研究结合N-末端测序技术和肽指纹图谱技术,测定TaAFP的一级结构,并对其同源性进行分析.MALDI-TOF-MS质谱分析显示TaAFP的分子量为13637.711 Da.使用Trypsin(胰蛋白酶)、Hydroxylamine(羟胺)和Chymotrypsin(胰凝乳蛋白酶)分别对TaAFP酶解,并对各个酶解片段的肽指纹图谱进行解析和连接,最终确定TaAFP的一级结构为MARKVIALAFLLLLTISLSKSNAARVKYNGGESGGGGGGGGGGGGGGNGSG-SGSGYGYNYGKGGGQSGGGQGGGGGGGGGGGSNGSGSGSGYGYGYGQGNGGAQGQGSGGGGGGGGGGGGGGSGQGSGSGYGYGYGKGGGGGGGGGGDGGGGGGGGSAYVGRHE,测定覆盖度达到了100%.序列比对分析以及同源性分析结果显示,TaAFP是一种与植物细胞壁和抵抗寒冷相关的蛋白质.     

XRF技术在无铅化工艺产品分析中的应用

介绍了XRF技术对无铅化产品和无铅化工艺中铅的快速无损分析的原理及其在实际检测中的应用. 采用自行研制的XRF-1000X射线荧光仪对无铅焊料及镀层进行快速无损分析, 其过程简单、结果准确、精度高.     

用近红外光谱法快速测定头孢曲松钠色差

应用近红外光谱分析技术,建立了头孢曲松钠色差的检测模型,并快速、准确地测定了头孢曲埝钠的色差。实验结果表明：近红外光谱分析方法的预测值与化学分析值有显著的相关性,相关系数为0．9783。     

因子分析法在混合酸各组分浓度测定中的应用

首次建立了在定pH滴定条件下,混合酸中各组分浓度与量测值滴定体积和溶液pH之间关系的数学模型。采用因子分析法求解,可确定被测体系中组分数和各组分含量,适用于多组分多样品的同时测定。     

Use of the ion microanalyzer for the characterization of bulk and epitaxial silicon and gallium arsenide

The ion microanalyzer permits a localized mass spectrometric analysis, i.e. the qualitative and quantitative analysis of the impurities contained in a small selected volume. This procedure makes possible the analysis of very thin epitaxial layers (for example silicon and gallium arsenide). As regards qualitative analysis, the apparatus is designed for the selection of ions. After the recording and analysis of the ion spectrum, a large number of the impurities present in the sample are determined qualitatively. Quantitative analysis can be performed with the equipment, but this requires the analysis of a homogeneous standard sample previously dosed by spark-source mass spectrometry. The quantitative analysis of bulk and epitaxial silicon and gallium arsenide is described and the limits of detection of the principal impurities are given. It is also shown how the possibility of localized analysis was exploited. A correlation was established between the existing impurities and the chemically revealed crystal imperfections. A comparative analysis of the distribution of the impurities in the epitaxial layers was also carried out. The periodic analysis of epitaxial layers makes it possible to follow the deterioration by contamination, if any, under the epitaxial conditions, and to improve the sample quality.     

Quantitative Determination of Hydroxycoric Acids and the Analysis of the Dynamics of Their Accumulation in Malus sylvestris Leaves

Abstract—The presence of hydroxycinnamic acids in the leaves of Malus sylvestris Mill. and Malus domestica Borkh. is established by using HPLC analysis. The quantitative determination of hydroxycinnamic acids is carried out by spectrophotometric analysis. It is found that the maximum amount of hydroxycinnamic acids accumulates in the plant during the fruiting phase.     

毛细管电泳在完整哺乳动物细胞分析中的应用

作为人体形态结构、生理功能和生长发育的基本单位,细胞的结构功能及行为分析具有重要的研究价值。毛细管电泳作为日渐成熟的微量分析技术在细胞分析及应用方面已取得显著进展。本文综述了毛细管电泳在完整哺乳动物细胞分析中的应用,包括群体细胞分析和完整单细胞分析。所述内容涉及血红细胞、公猪精子、人宫颈癌细胞、人神经母细胞瘤细胞、人结直肠腺癌细胞、人慢性髓系白血病细胞以及鼠小脑颗粒细胞。总结了完整哺乳动物细胞分析的毛细管电泳方法和条件,归纳分析了完整细胞分析中存在的细胞破碎、聚集、沉降、吸附及电泳异质性等关键问题及解决方法。对毛细管电泳在细胞分析方面未来的应用方向进行了展望。综述文献49篇。     

Redox sub-superequivalence method of radiometric analysis. Determination of trace amount of antimony

A new sub-superequivalence method of radiometric analysis is proposed, which is derived by combining the sub-superequivalence method of isotope dilution analysis with substoichiometric radiometric analysis. This method using redox reaction is applied for the determination of trace amount of antimony and was proved to be an excellent technique. The fundamental problems of this method are discussed analytically.     

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.     

Standardless X-ray analysis of bulk specimens

The paper gives an overview of the problems of Standardless analysis of bulk specimens by energy dispersive spectrometry (EDS) in scanning electron microscopes (SEM). The interest is concentrated on the present (and future) developments. The influence of the fluorescence excited by the continuum is discussed. Some improvements are proposed for the ionization cross-section. The difficulties due to the Coster-Kronig radiationless transitions are mentioned for the L lines. Emphasis is put on the necessity of an accurate modelling of the detector window, in order to be able to calculate reliably the efficiency of detection, mainly for the ultra-light elements. It is shown that some hypotheses such as the continuity of the fluorescence yield with the atomic number, which are currently accepted for heavier elements, could be wrong in the field of ultra-light elements. The capability of Standardless analysis in special situations is discussed: analysis at oblique electron beam incidence, analysis of specimens with a thin conductive coating, analysis of stratified specimens.     

Computer analysis of complex gamma-ray spectra from semiconductor detectors

The problem of gamma-ray spectrum analysis is treated by combination of peak-searching, choosing the fitting intervals and fitting the line shape by a shape function. The performance of the program is examined by analysis of a test spectrum,^177mLu.     

Application of two-dimensional variance analysis for the investigation of homogeneity of solids

Homogeneity of solids can be examined by two-dimensional variance analysis. The particular advantages are that trends in inhomogeneity and concentration gradients can be detected, and that the total error and procedural error are obtained from the same experimental data. The distribution of boron in an iron surface is described as an example. The procedural error always contains an interaction (correlation) contribution which cannot be eliminated by general rules. This contribution is negligibly small for measuring concentration gradients but can be large for stochastical distributions. In the latter case, conventional stochastical selection of measuring points and simple variance analysis is preferred to two-dimensional variance analysis.     

Routine analysis of ultra pure water by ICP-MS in the low- and sub-ng/L level

The chemical analysis with inductively coupled plasma-mass spectrometry (ICP-MS) can help to examine the purity of ultra pure water (UPW) down to 10 part per trillion (ng/L) and lower. For a proper determination of a high number of samples per week the analysis must be divided into two parts: the routine analysis and the reference water analysis. The routine analysis is done by direct measurement of the ultra pure water samples. Applying a standard addition method under particular clean conditions, the reference water analysis leads to the definition of the accurate zero. A quick evaluation scheme is also presented for the reference water analysis. The method is tested for its fitness for application by examining LOD (for relevant element < 2 ng/L), reproducibility and linearity of calibration. The ICP-MS was optimized according to the methodology of G. Taguchi to improve reproducibility and LOD.