共查询到20条相似文献,搜索用时 250 毫秒
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综述了人工神经元网络方法在毛细管电泳和色谱分析中的应用,内容包括迁移(或保留)行为的预测,分离优化,模式识别及分类,重叠峰定量解析,非线性过程的模型化,峰纯度的判断等。还对人工神经元网络在色谱和毛细管电泳中将来可能的应用进行了探讨。引用文献52篇。 相似文献
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毛细管电泳激光诱导荧光检测信号的小波滤噪 总被引:3,自引:0,他引:3
采用小波滤噪方法对毛细管电泳激光诱导荧光检测信号进行了处理,研究了小波变换中小波基的选择及噪声阈值的选择对滤噪的影响。结果表明,采用DB4小波基能有效消除毛细管电泳激光诱导荧光检测信号中存在的噪声,使信噪比得到较大改善。 相似文献
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增强型电荷耦合器件用于毛细管电泳激光诱导荧光的检测 总被引:3,自引:0,他引:3
增强型电荷耦合器件用于毛细管电泳激光诱导荧光的检测马明生,吴晓军,刘国诠(中国科学院化学研究所,北京,100080)关键词增强型电荷耦合器件,激光诱导荧光,毛细管电泳,异硫氰酸荧光黄近年来,毛细管电泳技术在生化分离、分析中得到广泛的应用。目前,毛细管... 相似文献
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连翘的毛细管电泳指纹图谱研究 总被引:13,自引:0,他引:13
采用毛细管区带电泳法,以75 mmol/L硼砂溶液(用0.1 mmol/L氢氧化钠溶液调pH 9.7)为背景电解质,运行电压14 kV,检测波长228 nm,重力进样15 s(高度9 cm),建立了连翘药材的毛细管电泳指纹图谱(CEFP)。将10个不同产地的连翘药材进行比较,按各电泳峰共有率fi≥70%作为选择电泳指纹峰的依据,确定连翘的毛细管电泳指纹峰为29个。在方法的精密度和重复性试验中,各指纹峰的相对迁移时间的相对标准偏差(RSD)不大于5%,相对峰面积的RSD约为2%~15%。10个产地的连翘药材的CEFP与其对照CEFP的相似度均不低于0.94。同时,采用指纹图谱信息量指数I和相对信息量指数Ir评价了10个产地连翘药材的质量差异。 相似文献
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毛细管区带电泳法测定尿中甲酸含量 总被引:1,自引:0,他引:1
采用高效毛细管区带电泳法测定人体尿中甲酸含量,尿样经过滤后直接进样,方法简单、快速,测定结果令人满意。电泳电解质体系采用5mmol/L邻苯二甲酸氢钾,0.5mmol/L十六烷基三甲基溴化铵,pH6,50cm×50μmi.d.熔融石英毛细管(有效长度48.5cm),检测波长210nm,负电源,分离电压30kV,压力进样,恒温25℃,每次电泳前用0.1mol/LNaOH及缓冲溶液对毛细管各冲洗5min。同时,采用检测波长与参比波长对调的方法使负峰转变为正峰。 相似文献
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García-Alvarez-Coque MC Simó-Alfonso EF Sanchis-Mallols JM Baeza-Baeza JJ 《Electrophoresis》2005,26(11):2076-2085
A new model is proposed for characterizing skewed electrophoretic peaks, which is a combination of leading and trailing edge functions, empirically modified to get a rapid recovery of the baseline. The peak model is a sum of square roots and is called thereby "combined square roots (CSR) model". The flexibility of the model was checked on theoretical and experimental peaks with asymmetries in the range of 0-10 (expressed as the ratio of the distance between the center and the trailing edge, and the center and the leading edge of the chromatographic peak, measured at 10% of peak height). Excellent fits were found in all cases. The new model was compared with other three models that have shown good performance in modelling chromatographic peaks: the empirically transformed Gaussian, the parabolic Lorentzian-modified Gaussian, and the Haarhoff-van der Linde function. The latter model was proposed recently to describe electrophoretic peaks. The CSR model offered the highest flexibility to describe electrophoretic peak profiles, even those extremely asymmetrical with long tails. The new function has the advantage of using measurable parameters that allow the direct estimation of peak areas, which is useful for quantitative purposes. 相似文献
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The application of chemometric techniques to the resolution of overlapped peaks in capillary electrophoresis (CE) is described. When a physical separation can not be completely accomplished, chemometrics might still resolve the determination of the analytes mathematically. CE with diode array detection can provide a large amount of data consisting of spectra registered over time. In this study, the capillary electrophoretic separation of 1,2-naphthoquinone-4-sulfonate derivatives of amino acids is studied. Most of the common amino acid derivatives can be separated at 30 kV in a fused-silica capillary by using a 40 mM sodium tetraborate + isopropanol (3:1 v/v) solution as background electrolyte. However, peaks of certain derivatives (Phe, His, Leu and Ile) still overlap. A multivariate curve resolution method based on an alternating least squares optimization procedure is used for the resolution of the overlapped electrophoretic peaks. The method takes advantage of spectral and electrophoretic differences of analytes to recover their pure electrophoretic and spectral profiles. In addition, each analyte in the mixture can be quantified using the corresponding standards. 相似文献
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We present a novel method for the automated detection of fragments showing dissimilar expression in mRNA differential display. The analysis is based on aligning the numerical electrophoretic lane data in respect of a given distance function defined on a set of fragments, or signal peaks in general. We presume that significant dissimilarities between peaks result in extreme score values computed for aligned peak pairs. Whereas in sequence comparison, an overall sequence similarity score is conventionally used, the current method defines a special dissimilarity score for searching the peak pairs showing the largest relative differences between the lanes. The output of the analysis is a highly reduced list of peak pairs, along with a set of associated features extracted from the lanes. Only the peaks of this list need to be visually confirmed instead of the vast amount of peaks in the original electrophoretic results. The results obtained by the algorithm correlate well with results of visual evaluation of the same electropherograms. The current algorithm may be applied to the study of complex expression patterns in multiple lanes and, in general, to automated recognition of variously defined patterns of quantitative electrophoretic data. 相似文献
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为提高电子纸电泳分散液(电泳液)的稳定性并降低使用电压,采用毕克公司的BYK161和BYK110对二氧化钛等颜料复配,制备高稳定的红、绿、蓝、黄、黑各色电泳液,组装成电子纸器件,通过紫外分光光度计对电子纸颜料的反射特征峰进行动力学测试,研究它们的对比度与双稳性,经测定:所得电子纸具有相同的开关时间(470-510 ms),沉降时间(t1/3)为72 h,对比度可达7,具有良好的双稳性,适用于低电压多色电子纸显示。 相似文献
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Two techniques for identifying the peaks of phenylthiohydantoin (PTH) amino acids separated under the conditions of micellar electrokinetic chromatography were compared. The first technique is linear regression analysis, in which the retention time of an amino acid is a function of the retention times of two retention-time standards. The second technique takes into account hydrophobicity constants logD′, which were calculated using the ACD/LC Simulator 8.0 program package from ACDLabs (Canada). These constants provide an opportunity to calculate the relative migration times of PTH amino acids taking into account the velocity of the electroosmotic flow. The first technique allows us to identify the electrophoretic peaks of all 16 amino acids separated; the second procedure allows us to predict the elution order of the electrophoretic peaks; the use of a correlation equation gives better results. 相似文献
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We determined the feasibility of using capillary electrophoresis with postcolumn laser-induced fluorescence (CE-LIF) detection to characterize electrophoretic properties of isolated cell nuclei and impurities present in nuclear fractions. These fractions were isolated from NS-1 mouse hybridoma cells, stained with hexidium iodide, a DNA intercalating dye, and analyzed by CE-LIF detection. The corresponding electropherograms display two features: (i) broad peaks (6-90 s wide) caused by the cell culturing media and by free-DNA intercalated with hexidium iodide, and (ii) a large number of narrow peaks (180 ms wide), resulting from DNA associated with individual intact or disrupted nuclei. We confirmed that the narrow peaks were not caused by contaminating mitochondria. The overall electrophoretic mobility range of disrupted nuclei is 0 to -5 x 10(-4)cm(2)/Vs, while intact nuclei seem to have mobilities in the -1.5 to -3.5 x 10(-4)cm(2)/Vs range. Furthermore, the highly sensitive CE-LIF method reveals a high abundance of disrupted nuclei that cannot be directly observed by confocal microscopy. 相似文献
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When pure avidin is chromatographed on a homemade iminobiotin column, two distinct peaks are observed using a gradient solvent system starting with a pH 9 buffer. Proteins in both peaks are shown to be identical by nondenatured polyacrylamide gel electrophoretic experiment. The weak interaction of the protein with the stationary phase at pH 9 could cause this unusual behavior. 相似文献
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H Cottet P Gareil P Guenoun F Muller M Delsanti P Lixon J W Mays J Yang 《Journal of chromatography. A》2001,939(1-2):109-121
Water soluble diblock copolymers composed of a long poly(styrene sulfonate) chain (between 200 and 400 monomers) and a short poly(ethylene propylene) or poly(tert.-butylstyrene) hydrophobic end (20-50 monomers) are highly associative and form micelles in aqueous solution. The micelles are composed of a small hydrophobic core and a polyelectrolyte corona, the dimensions of which can be estimated by neutron and light scattering. These physical techniques are, however, not amenable to discriminate easily between the free copolymer and the copolymer micelle. Capillary electrophoresis was implemented in this work as a new and effective tool to investigate the behaviour of such associative copolymer systems. Since the rate of exchange between the micellised and free states is very slow in comparison with the time scale of the electrophoretic process, the electropherograms of the diblock copolymers obtained in plain aqueous borate buffers exhibit two peaks assigned to the two states mentioned above. The identification of the two peaks was first made on the basis of the retention orders of the two peaks equally obtained in similar conditions by size-exclusion chromatography. The copolymer micelles appeared to have a smaller electrophoretic mobility than the free copolymers. This peak assignment is also consistent with the observed ratio of the time-corrected peak areas and peak dispersions. The effects of the copolymer concentration, electric field, temperature and hydroorganic composition of the medium was also studied. Such systems do not exhibit a defined concentration threshold equivalent to a classical critical micelle concentration. Adding methanol to the electrolyte resulted in the progressive loss of baseline return between the two peaks, which might be attributed to a slight increase in the rate of exchange between the two states. Finally, adding a neutral surfactant to the electrolyte at a concentration in excess of its critical micelle concentration resulted in a decrease in the electrophoretic mobility of the peak attributed to the free copoplymer, while the electrophoretic mobility of the copolymer micelle remained unperturbed. 相似文献
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Summary A capillary electrophoretic method has been developed for determination of the components of the paromomycin mixture salt.
Paromomycin was detected at 330 nm after pre-capillary derivatization witho-phthaldialdehyde and thioglycolic acid. The electrophoretic separation was performed in a fused-silica capillary at 25°C
and 18kV with a background electrolyte comprising 40mm sodium tetraborate, 3mm β-cyclodextrin, and 12.5% (v/v) methanol. Although the analysis time was reduced to 10min, five peaks could be separated
to baseline. The relative standard deviation of the ratios (peak area/internal standard peak area) was <5% for all peaks. 相似文献