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。     

复杂色谱信号自动解析中的化学计量学方法

色谱及其联用技术日趋完善,并向自动化、高通量和快速的方向发展。化学计量学利用"数学分离"手段,可以实现色谱信号的自动化解析,已成为现代色谱分析中非常活跃的研究领域。但以往的化学计量学方法并不能完全有效地实现复杂色谱信号自动化解析。为此,自动化色谱解析算法成为科研工作者关心的重点,众多新型的自动化解析算法被提出。针对复杂一维色谱数据以及联用仪器得到的二维和更高维数据的自动化分析,化学计量学研究主要集中在自动色谱峰识别、背景以及基线漂移校正、色谱谱峰漂移校正以及重叠色谱峰的解析。该文对近十年来发展的复杂体系色谱信号自动化解析中化学计量学方法的原理与应用进行了总结与评述,比较了各类方法的优势与不足。在此基础上,针对当前色谱自动化分析过程中的难题对未来该领域的研究方向进行了展望。     

一种新型的信号拟合方法--免疫算法

通过对免疫系统免疫机制的模拟,提出了一种新型的信号拟合算法。该算法根据所提供的标样信息对重叠分析化学信号进行拟合,从重叠信号中提取单一组分的信息,从而实现了多组分混合信号的解析。对模拟信号的实验信号的处理结果表明,该方法可方便地用于多组分重叠色谱信号的解析。     

一种新型的信号拟合方法─—免疫算法

通过对免疫系统免疫机制的模拟,提出了一种新型的信号拟合算法。该算法根据所提供的标样信息对重叠分析化学信号进行拟合,从重叠信号中提取单一组分的信息,从而实现了多组分混合信号的解析。对模拟信号和实验信号的处理结果表明,该方法可方便地用于多组分重叠色谱信号的解析。     

一种基于免疫算法的新型因子分析算法

基于免疫算法的基本思想,提出了新的免疫主成分分析法(IPCA),该方法将免疫算法中抗体对抗原的消除运算应用于二维数据矩阵的正交分解,可得到矩阵的特征值和特征向量.结果表明,IPCA与传统的主成分分析法比较,对HPLC-DAD模拟信号的计算结果基本一致.对HPLC-DAD实验信号的解析结果表明,将IPCA与窗口因子分析技术结合比传统的WFA具有更强的解析能力.     

信号处理技术在重叠化学信号解析中的应用*

重叠峰解析是目前分析化学中亟须解决的一个重要问题,化学计量学用于重叠峰解析就是借助某些数学或统计学方法,把通过化学方法和仪器未能完全分离的复合量测信号分解成几个单儿组分的信号,从而从重叠谱中获取每个组分的相关信息。本文综述了几种常见信号处理技术在重叠化学信号分辨中的应用,引用文献146篇。     

免疫-遗传算法用于混合物重叠核磁共振信号解析

通过对免疫系统中抗体对外来抗原的识别、消除等过程的模拟,建立了一种新型的免疫算法模型.将标样信号作为抗体,混合物重叠信号作为抗原输入免疫算法模型,通过迭代运算,从抗原中消除抗体所表示的信息,当抗原被抗体完全消除时,即实现了混合物重叠信号的解析.对多组分混合氨基酸NMR谱图的解析结果证明,该算法可方便地用于多组分重叠信号的解析,为利用数据库解析混合物或生物大分子等物质的复杂NMR谱图开辟了一条全新的途径.     

完全重叠色谱峰的二维微分色谱解析算法

利用完全重叠的色谱峰中同时消失的两组分的浓度变化速率差异，通过二维数据微分色谱法获取被掩盖组份的近似光谱，以解析完全重叠的色谱体系，将该法应用于维生素Ｃ和菸酸两组份完全重叠的二维色谱之分辨，结果令人满意，分辨光谱与标准光谱重合甚好。     

基于高通量解析算法的复杂样品重叠气相色谱-质谱信号的快速分析

化学计量学算法为重叠气相色谱-质谱(GC-MS)信号的解析提供了有效手段,但其在计算过程中一般需要将数据进行分段处理,然后只对信号的某些区间进行解析,难以实现真正意义上的高通量分析。该文结合移动窗口目标转换因子分析(MWTTFA)和非负免疫算法(NNIA),建立了一种高通量解析方法。首先,根据所有可能存在的目标组分的标准质谱信息,利用MWTTFA检验复杂信号中存在的组分,并确定目标组分的质谱信息和洗脱时间区域。以得到的质谱信息作为后续计算的输入值,利用NNIA解析得到相应的色谱信息。采用快速升温程序对17种和42种农药混合标准样品的GC-MS信号进行分析,利用所建立的方法可在10 min内得到全部组分的色谱和质谱信息。     

熵最小算法解析中药挥发油GC-MS谱中同分异构体的研究

采用以熵最小算法为基本原理的化学计量学方法,结合气相色谱-质谱联用分析法,对玫瑰精油及茉莉花挥发油中的2对同分异构体重叠峰进行重建分析,并分别得到各组分的重建质谱,同时采用NIST数据库相似度检索、质谱碎片信息比对及程序升温指数对分析得到的各组分进行定性分析。通过分析,分别从玫瑰精油和茉莉花挥发油的GC-MS重叠峰中分离得到1对同分异构体。分析结果显示,采用熵最小算法可以成功地对重叠峰中的各组分进行定性分析。该研究为类似同分异构体混合物中各组分的测定提供了参考。     

A post-modification approach to independent compo-nent analysis for resolution of overlapping GC/MS signals: from independent components to chemical components

Independent component analysis (ICA) has demonstrated its power to extract mass spectra from over-lapping GC/MS signal. However, there is still a problem that mass spectra with negative peaks at some m/z will be obtained in the resolved results when there are overlapping peaks in the mass spectra of a mixture. Based on a detail theoretical analysis of the preconditions for ICA and the non-negative property of GC/MS signals, a post-modification based on chemical knowledge (PMBK) strategy is pro-posed to solve this problem. By both simulated and experimental GC/MS signals, it was proved that the PMBK strategy can improve the resolution effectively.     

自动化色谱谱图解析——谱峰的自动识别与快速解析

结合基于高阶导数的谱峰识别方法和面积重现法,建立了一种完全自动化的对色谱曲线进行分割、识别与快速解析的方法。其中,DW(Durbin-Watson)测试的引入和区分信号与噪声判据的采用减少了在色谱解析过程中的人为干预,降低了对操作人员专业知识和经验的要求,为实现色谱解析的自动化奠定了基础。通过对模拟色谱和实验色谱的比较,验证了该方法是一个很有用的工具,可以为色谱分析工作提供有力的帮助。     

Conformational analysis: a new approach by means of chemometrics

In conformational analysis, the systematic search method completely maps the space but suffers from the combinatorial explosion problem because the number of conformations increases exponentially with the number of free rotation angles. This study introduces a new methodology of conformational analysis that controls the combinatorial explosion. It is based on a dimensional reduction of the system through the use of principal component analysis. The results are exactly the same as those obtained for the complete search but, in this case, the number of conformations increases only quadratically with the number of free rotation angles. The method is applied to a series of three drugs: omeprazole, pantoprazole, lansoprazole-benzimidazoles that suppress gastric-acid secretion by means of H+, K+-ATPase enzyme inhibition.     

Resolving overlapping GC–MS signals with a multistep screening chemometric approach for the fast determination of pesticides

For the rapid analysis of multicomponent mixtures using GC–MS, a chemometric multistep screening approach was proposed to extract the signals of the components from the overlapping signals measured with a very fast temperature program. At first, independent component analysis was used to find all the possible mass spectra from the overlapping signal in the moving windows along the retention time, and iterative target transformation factor analysis was employed to validate the existence of the extracted spectra from each window. Then, identical signals in the validated spectra were excluded using match ratio as a criterion. Finally, the chromatographic profiles for each spectrum were calculated using non‐negative immune algorithm, and the spectra with a reasonable profile were taken as the identified components. A mixture of 53 pesticides was analyzed with a very fast temperature program of 7 min. A total of 48 pesticides and 16 interferences were identified from the overlapping GC–MS signal.     

Model‐free multivariate curve resolution combined with model‐based kinetics: algorithm and applications

Multivariate curve resolution techniques are powerful tools to extract from sequences of spectra of a chemical reaction system the number of independent chemical components, their associated spectra, and the concentration profiles in time. Usually, these solutions are not unique because of the so‐called rotational ambiguity. In the present work, we reduce the non‐uniqueness by enforcing the consistency of the computed concentration profiles with a given kinetic model. Traditionally, the kinetic modeling is realized in a separate step, which follows the multivariate curve resolution procedure. In contrast to this, we consider a hybrid approach that combines the model‐free curve resolution technique with the model‐based kinetic modeling in an overall optimization. For a two‐component model problem, the range of possible solutions is analyzed, and its reduction to a single, unique solution by means of the hybrid kinetic modeling is shown. The algorithm reduces the rotational ambiguity and improves the quality of the kinetic fitting. Numerical results are also presented for a multi‐component catalytic reaction system that obeys the Michaelis–Menten kinetics. Copyright © 2012 John Wiley & Sons, Ltd.     

大气颗粒物中有机物色谱分析的样品制备技术

大气颗粒物中有机物成分分析对深入研究大气颗粒物对人类健康、环境、气候、生态的影响,解析气溶胶来源,制定颗粒物控制相关法规,以及风险管理方法具有重要意义。由于颗粒物中的有机组分种类繁多,分析复杂,目前仅10%~20%的有机物得到了定性和定量分析。因此,大气细颗粒中有机物的分析已成为环境分析领域的优先发展方向。色谱是大气颗粒物中有机物分析的主要方法,而样品制备则是影响分析速度和精度的关键步骤。本文对颗粒物中有机组分色谱分析前的样品制备方法进行了综述,介绍了索氏提取、超声辅助提取、微波辅助提取、加压溶剂提取等溶剂提取方法以及热解吸提取方法,并重点介绍了这些方法在大气颗粒物样品处理中的应用,总结了各种方法的优缺点。     

A short history of chemometrics: a personal view

This article traces chemometrics back to its origins in scientific computing in the 1960s. Its development is compared in other computational disciplines such as bioinformatics. The change in geographical origins of papers published in the core chemometrics literature is discussed. It is concluded that the level of core activities in this area has hardly changed over several decades, whilst there has been a significant expansion in non‐expert users of packages over this period. It is estimated that around 2% of people encountering chemometrics in their research can be considered real experts. The problems of non‐experts using chemometrics methods with limited knowledge of the statistical fundamentals are explored. The contrasting development of chemometrics compared with, for example, computational chemistry and bioinformatics, is interpreted in terms of the changing financial pressures on research over its key developmental phase, as illustrated by the change in academic finance in the UK over the past 50 years. Copyright © 2014 John Wiley & Sons, Ltd.     

Generalized criterion of solvent polarity as a tool for control of chromatographic process

The generalized (reductive) criterion of solvent polarity was obtained by the method of multiparametric optimization of the Snyder index P", Hildebrand parameter _T , permittivity _r , and solvatochromism parameter E _T (30). Possibilities of employing this criterion for estimation of the elution power of normal and reversed mobile phases used in high-performance liquid chromatography were considered.