遗传算法在色谱谱图解析中的应用

将遗传算法引入色谱峰解析程序 ,结合色谱峰EMG模型及峰形经验公式 ,实现了恒温色谱谱图的全自动解析。对模拟谱图和实验谱图进行了解析 ,取得了满意的结果。本文对遗传算法的运算控制及运算效率进行了研究和讨论     

非对称色谱峰的拟合与重叠峰的拟合解析

 ]利用色谱保留时间tR与色谱峰形模型参数tG、σ、τ间的线性关系、预测了气相色谱填充柱上非对称的和重迭的色谱峰的有关参数，并据此对这两类色谱峰进行了拟合和解析。与常用重叠峰解析方法如中垂线法，三角形法和切线法解析结果的对比证明，曲线拟合法在这些方法中具有最好的准确度。用曲线拟合法进行实际定量的结果表明，对于非对称峰，其定量的相对误差小于0.5％，而对于重叠峰的定量误差则在10％以内。     

小波变换用于重叠色谱峰组分信息的提取

提出了一个小波变换用于提取重叠色谱中组分信息的理论公式，并将它应用于三组分和五组分重叠色谱实验数据的解析。结果表明：在定定分离度范围内，当相邻色谱峰峰宽相近时，根据此公式的计算结果，可以将各组分的信息从重叠色谱峰信号中提取出来。洒工作对小波变换用于重叠峰的解析具有重要意义。     

一种基于光谱分析的二元不完全重叠色谱峰的分离解析方法

基于二极管阵列检测器获得的色谱-光谱数据,建立了一种二元不完全重叠液相色谱峰的解析方法: 色谱数据经过去噪、归一化处理后,计算各时间点的光谱差异并进行系统聚类分析,提取特征光谱后,利用非负最小二乘法对色谱-光谱矩阵进行解析,得到基于特征光谱的流出曲线,进而得到分离后的色谱峰。将解析结果和纯标样的色谱峰进行比较,解析后的光谱图和纯标样的光谱图无显著差异,保留时间相差小于0.01 min。实验结果表明,该方法在二元不完全重叠液相色谱峰的解析方面能取得良好的效果。     

用熵最小算法解析桂郁金挥发油GC-MS重叠谱

采用气相色谱-质谱(GC-MS)联用技术对桂郁金中提取的挥发油成分进行检测,同时用熵最小算法对其中的共流物色谱峰进行解析,并通过质谱库检索和程序升温保留指数相结合的方式对解析得到的各纯组分进行定性分析。将桂郁金挥发油各组分的质谱数据直接与美国国家标准及技术研究所(NIST)数据库进行比对,鉴定出38个化合物;在挥发油的色谱图中,存在一些因分离不完全而导致的共流物色谱峰,以保留时间为1 106.52~1 108.38 s及1 184 s的色谱峰为例,经熵最小算法解析,共发现5个纯组分。采用熵最小算法可以清楚地对共流物色谱峰进行解析并得到所包含的各个纯组分,该法可提高复杂成分定性定量分析结果的准确性。     

GC/FTIR数据的计算机解析—煤焦油洗油分析

本文提出了一个可以进行红外光谱解析和谱库检索的计算机程序。该解析程序将红外特征吸收频率、色谱保留指数和谱库检索结果三者结合起来,可迅速而准确地鉴定色谱峰,并能绘制出各色谱馏出物的吸收光谱图和谱库中最近似的参比光谱图,核对方便。当库存光谱数据资料中没有待检索的化合物时,仍能根据特征吸收频率和保留值数据作出较为正确的判断。此法用于分析煤焦油洗油馏份,可得到满意的解析结果。     

严重重叠的色谱峰对的解析

本文根据指数修正的高斯函数模型(EMG),并利用回归分析提出了一种解析严重重叠的色谱峰对的方法。此法可适用于相对峰谷在50％～95％的严重重叠的色谱峰对的解析。     

免疫算法用于多组分二维色谱数据的解析

通过对免疫系统抗体对抗原消除作用及其记忆功能的模拟,提出了解析二维数据矩阵的新方法。采用模拟的EMG公式作为抗体输入,对二维信号逐行进行迭代消除,从重叠峰中提取单一组分的色谱信息和光谱信息。通过对二维色谱数据的解析,结果表明,该方法可方便地用于多组分重叠二维色谱的解析。     

小波变换及其有色谱重叠峰解析中的应用

本文介绍了小波分析的基本原理、计算方法及其在色谱重叠峰解析中的应用。显示了小波分析的特点，表明了小波分析用于重叠峰的解析与传统的方法相比具有其优越性。     

小波变换及其在色谱重叠峰解析中的应用

本文介绍了小波分析的基本原理、计算方法及其在色谱重叠峰解析中的应用。显示了小波分析的特点，表明了小波分析用于重叠峰的解析与传统的方法相比具有其优越性。     

General method for suppression of diagonal peaks in heteronuclear-edited NOESY spectroscopy

A novel approach is proposed for suppression of diagonal peaks in 15N- and 13C-edited NOESY spectroscopy based on subtracting a spectrum with only diagonal peaks from the conventional NOESY spectrum. This method can be applied to most heteronuclear-edited NOESY experiments. It is far more sensitive than the TROSY-based approach for biomolecules with little TROSY effect, and nearly complete suppression of diagonal peaks can be achieved. The method has been demonstrated on samples of 15N-labeled calmodulin (17 kDa), 13C-labeled DdCAD-1 (24 kDa), and 13C-labeled hemoglobin (65 kDa), showing that cross-peaks very close to diagonals can be assigned reliably based on the difference spectra.     

Quantification of components in overlapping peaks from capillary electrophoresis by using continues wavelet transform method

The application of continues wavelet transform (CWT) for resolving overlapping peaks from capillary electrophoresis (CE) is described. Overlapping peaks can be resolved easily by transforming experimental signals into their wavelet coefficients. The proposed method was applied for the determination of benzoic acid and salicylic acid in overlapping peaks from CE. The composition of the two acids in Zuguangsan, a traditional Chinese patent medicine, was determined. The quantification results are satisfactory. CWT has been shown to be a practicable approach for resolving overlapping peaks and for quantitative determining coeluted compounds in overlapping peaks from CE. The quantification results obtained from CWT were compared with those obtained from numerical differentiation method. CWT has been shown prior to numerical differentiation method for processing experimental signals which contain noise.     

Application of wavelet transforms and an approximate deconvolution method for the resolution of noisy overlapped peaks in DNA capillary electrophoresis

A new procedure for resolving noisy overlapped peaks in DNA separations by capillary electrophoresis (CE) is developed. The procedure combines both a wavelet-based denoising method that effectively denoises the signal and a novel approximate deconvolution technique that resolves the fragment peaks and improves the ability to separate highly overlapped peaks early in the electrophoresis process. Different kinds of overlapped peaks with and without noise simulated by computer as well as some DNA experimental electropherograms were submitted to the new procedure. A second order differential operator with variable coefficients is applied to the entire electrophoresis signal at any given time and approximate deconvolutions of the individual Gaussian peaks are performed. The operator incorporates the effect of the superposition and gives exact annihilation in the neighborhood of each peak. Overlapped peaks with a resolution higher than 0.46 can be resolved directly. Also, the method can determine the peak components of signals with a signal to noise ratio higher than 1.4     

Criteria for judging the quality of separation in chromatograms containing solvent peaks

Summary Formal procedures used for optimizing chromatographic selectivity require objective, numerical functions to assess the quality of each chromatogram obtained during the process. Many of such optimization criteria have been suggested for chromatograms in which all or a number of well-shaped peaks need to be separated. This paper describes a method by which resolution can be measured in chromatograms in which very large, highly non-symmetrical background peaks,e.g. typical solvent peaks, are present. Using this method, various optimization criteria can be calculated. The method is evaluated using a simulation program which constructs chromatograms from the recorded profiles of individual experimental peaks. It is also demonstrated for use in an experimental optimization procedure in reversed-phase liquid chromatography.     

Translation Modification Iteration for Resolution and Quantification of Overlapping Chromatographic Peaks

A novel algorithm, translation modification iteration (TMI), is proposed for resolving overlapping chromatographic peaks. By this method, a series of similar peaks are obtained from the initial construction of single component peaks and approach the profiles of real single component peaks by iteration. Both simulated and experimental data are investigated with TMI, consequently overlapping peaks can be resolved into reasonable single component peaks easily and efficiently. Quantitative analysis is also successfully achieved in both simulated and experimental data, and the quantitative results obtained from TMI are superior to those obtained from perpendicular drop (PD) and tangent skim (TS) methods. Without too much time devoted to the procedure, TMI is a simple and practicable method for resolution and quantification of overlapping chromatographic peaks.

     

凝胶纳米氧化钛Raman光谱研究

纳米材料近来成为材料科学的研究热点[1]．催化剂实际上大多是纳米材料．TiO2有多方面的用途，比如它是重要的新型催化剂载体，其纳米微粒，由于比表面高，将有利于改善其催化性能[2]．Raman光谱是研究纳米微粒的新手段，现已发现随着拉径减小到纳米县级，原有Raman峰将产生低频位移和宽化，还可能出现新峰．另外，低频Raman谱段还可能出现散射峰，这些现象均可提供宝贵的纳米结构信息[7,8]．文献中对锐钛矿型TiO2纳米粒子的研究较少[4],而未见对其进行低频Raman测量的报道.本文对用sol-gel方法经不同制备条件合成的一系列锐钛矿型纳米T…     

养血清脑颗粒的高效液相色谱指纹图谱研究

采用变换波长检测法建立了养血清脑颗粒HPLC指纹图谱,确定了35个共有色谱峰在药材中的归属,并用液相色谱-质谱联用(LC-MS/MS)法鉴定出部分化学成分,同时对制剂中的4种指标性成分进行了定量检测.结果表明,制剂与药材具有良好的色谱峰相关性,4种指标性成分在各自的浓度范围内线性关系良好(r＝0.9997～0.9999...     

三元重叠色谱峰面积的定量方法

本从色谱峰的ＥＭＧ模型出发，通过对重叠色谱峰的模拟和回归分析，提出了一种三元重叠色谱峰的面积的定量方法，三元重叠色谱峰的每一个峰面积可以由峰面积比和总面积求得，此法所需的数据都由实验色谱图上测得，峰面积计算结果的相对误差小于±５％，适用于相对峰谷为５０％－９５％的三元重叠色谱峰面积的定量。     

Deconvolution of composite chromatographic peaks by simultaneous dual detections

Composite chromatographic peaks are deconvoluted by a method that uses ratio formation from signals of simultaneous double detection. The method is generally suitable if two detector signals can simultaneously be acquired and their uses do not need any a priori assumption or mathematical shape analysis. A simple deduction makes the compound- and detector-specific intensive parameters explicit, which allows for the digital construction of directly invisible component peaks. The simultaneous double detection is shown to be superior to coupled detectors, sequentially fixed chromatograms, and subsequently synchronized peaks. The combination of circular dichroism and ultraviolet (UV) detection is shown to be especially advantageous in the analysis of enantiomers for which the other ratio-forming peak-deconvolution techniques have inherently been insensitive. The double chiroptical UV detection can be of further use to decompose overlapping peaks of nonenantiomeric compounds that are highly similar. The capacity of the method is exemplified by the analysis of morphine alkaloids, steroid oximes, and synthetic heterocycles.