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。     

锕系元素化学及教学建议

依据文献和最新研究进展,从锕系元素特殊电子结构出发,着重于从锕系理论、非正常氧化态、单质的特性、水溶液中的重要反应、元素分离和应用等方面论述了锕系元素与镧系元素的差异,认识锕系元素化学,并给出教学建议。     

化学计量学方法在脂质组学数据解析中的应用

脂质组学是依赖于分析技术而发展的一门新兴学科,用于全面表征与基因调控、蛋白表达、脂质代谢密切相关的脂质分子,揭示脂质在各种生命活动中的作用机制和代谢途径网络。随着质谱及其联用技术进一步发展和完善,脂质组学逐渐向快速、自动化和高通量的方向发展,而大规模的脂质组数据分析已成为脂质组学研究领域的一大难点。化学计量学主要应用于脂质组学中的基线校正和背景扣除、信号峰识别、同位素分布解析、统计分析等过程,因此,基于化学计量学方法的脂质组学数据自动化解析策略成为研究者关心的热点。该文对近年来化学计量学在脂质组学数据解析中的应用进行了综述,并对基于化学计量学的脂质组学数据解析的未来发展进行了展望。     

用于癌症病人初级临床诊断的化学计量学研究

用感应耦合等离子体原子发射光谱及石墨炉原子吸收测定了正常人及癌症病人头发与血清样品中13个元素。将所得数据送入计算机, 分别用化学计量学中PLS及Gram-Schmidt多元分析方法处理了血清与头发样本。在两种情况下均得到了病人与正常人分类极其清晰的二维判别图。头发样本的判别失误率低于血清样本。头发样品取样、存储及运输容易, 也宜于进行光谱分析, 因此可将头发用作癌症初级临床诊断中的分析样品。     

《化学计量学方法》（第二版）简介

《化学计量学方法》(第二版)在第一版的基础上补充了最新出现的化学计量学研究方法和最新的研究成果。该书包括了化学计量学的主要内容,全书共分 15章,分别为误差及与数理统计基础、回归分析、相关分析和数据平滑、最优化方法、主成分分析和因子分析、偏最小二乘方法、多元校正及分辨、小波分析、遗传算法和模拟退火算法、人工神经网络法及在化学中的应用、模拟识别方法、化合物结构表征和构效关系研究、组合化学、谱图库检索和结构解析专家系统及实验设计。此外,为方便读者查阅,该书还将常用数据信息列为附表。《化学计量学方法》(第二…     

多元校正-速差动力学分光光度法同时测定三组分有机磷农药

速差动力学分析结合化学计量学对动力学数据进行解析计算, 可扩大动力学分析的范围, 提高分析的准确度. 本文利用对硫磷、甲基对硫磷和杀螟硫磷在碱性介质中能与氧化剂过氧化氢发生氧化反应生成对硝基苯酚的性质, 引入多元校正方法中的经典最小二乘法(CLS)、偏最小二乘法(PLS)和主成分回归法(PCR)对动力学数据进行解析, 实现了三组分人工合成样品的同时测定.     

《化学计量学方法》（第二版）简介

《化学计量学方法》(第二版)在第一版的基础上补充了最新出现的化学计量学研究方法和最新的研究成果。该书包括了化学计量学的主要内容,全书共分15章,分别为误差及与数理统计基础、回归分析、相关分析和数据平滑、最优化方法、主成分分析和因子分析、偏最小二乘方法、多元校正及分辨、小波分析、遗传算法和模拟退火算法、人工神经网络法及在化学中的应用、模拟识别方法、化合物结构表征和构效关系研究、组合化学、谱图库检索和结构解析专家系统及实验设计。此外,为方便读者查阅,该书还将常用数据信息列为附表。《化学计量学方法》(第二版)作…     

《化学计量学方法》（第二版）简介

《化学计量学方法》（第二版）在第一版的基础上补充了最新出现的化学计量学研究方法和最新的研究成果。该书包括了化学计量学的主要内容，全书共分15章，分别为误差及与数理统计基础、回归分析、相关分析和数据平滑、最优化方法、主成分分析和因子分析、偏最小二乘方法、多元校正及分辨、小波分析、遗传算法和模拟退火算法、人工神经网络法及在化学中的应用、模拟识别方法、化合物结构表征和构效关系研究、组合化学、谱图库检索和结构解析专家系统及实验设计。此外，为方便读者查阅，该书还将常用数据信息列为附表。     

化学计量学在激光诱导击穿光谱分析中的研究进展

激光诱导击穿光谱作为一种新兴的元素分析技术,具有实时在线、非接触、多元素同时检测等优点,是光谱分析领域内的一种前沿性分析手段.然而,如何从复杂大量的激光诱导击穿光谱数据提取有用信息,提高其定性、定量分析准确度是激光诱导击穿光谱技术目前面临的难题.化学计量学作为多学科交叉的化学分支学科,在数据处理、信号解析和模式识别等方面具有优势,能够解决传统化学研究方法难以解决的一些复杂问题.本文从光谱数据预处理、定性和定量分析三方面综述了近年来化学计量学方法在激光诱导击穿光谱中的研究进展.     

运用色谱指纹图谱与化学计量学方法对灵芝进行分类

采用95%乙醇为提取溶剂,运用高效液相色谱(HPLC)指纹图谱技术与化学计量学方法,对11个不同灵芝菌株子实体进行分类。通过相似度分析分别获得提取样品指纹图谱的13个共有峰及每个样品之间的相似度;以相对共有峰面积为分析参数,运用化学计量学方法包括聚类分析(HCA)、主成分分析(PCA)及判别分析(DA)对其进行分类,结果分为紫芝、赤芝和美国大灵芝3类。实验结果表明,用化学计量学的方法对灵芝样品的指纹图谱数据进行分析,是一种可用于其分类的科学方法。     

化学计量学―光谱法在工农业生产中的应用

化学计量学是近几年发展迅速的化学量测方法。常用的化学计量学方法有小波变换、多元线性回归、偏最小二乘法、主成分分析、人工神经网络、遗传算法等。化学计量学方法与光谱法相结合广泛运用于工业生产、农业生产和环境监测等各个领域,体现出化学计量学在数据处理、信号解析等方面的重要作用。化学计量学―光谱法的建立为工、农业生产中多组分混合物的快速、准确测定及满足质量监控等要求提供了一条有效的途径。     

Chemometrics comes to court: evidence evaluation of chem–bio threat agent attacks

Forensic statistics is a well‐established scientific field whose purpose is to statistically analyze evidence in order to support legal decisions. It traditionally relies on methods that assume small numbers of independent variables and multiple samples. Unfortunately, such methods are less applicable when dealing with highly correlated multivariate data sets such as those generated by emerging high throughput analytical technologies. Chemometrics is a field that has a wealth of methods for the analysis of such complex data sets, so it would be desirable to combine the two fields in order to identify best practices for forensic statistics in the future. This paper provides a brief introduction to forensic statistics and describes how chemometrics could be integrated with its established methods to improve the evaluation of evidence in court. The paper describes how statistics and chemometrics can be integrated, by analyzing a previous know forensic data set composed of bacterial communities from fingerprints. The presented strategy can be applied in cases where chemical and biological threat agents have been illegally disposed. Copyright © 2015 John Wiley & Sons, Ltd.     

Sequential determination of Am, Cm, Pu, Np and U by extraction chromatography

Environmental contamination by artificial radionuclides and the evaluation of their sources require precise isotopic analysis and accurate determination of actinide elements above all plutonium and americium. These can be achieved by alpha spectrometry or by inductively coupled plasma mass spectrometry (ICP-MS) after chemical separation. In the present work, a simple, rapid method has been developed for the sequential separation of actinide elements from aqueous solutions and their determination by alpha spectrometry. Extraction chromatography was applied to the separation of ²⁴¹Am, ²⁴⁴Cm, ^{239 + 240,238}Pu, ²³⁷Np and ^238,235,234U using microporous polyethylene supporting tri-n-octylamine as the stationary phase and hydrochloric acid with and without reducing agents as the mobile phase. Actinide in 9 M HCl solution is introduced into the anion exchange column; Pu (IV), Np (IV) and U(VI) are retained on the column while Am (III) and Cm passed through. Pu is eluted first, reductively, after which, Np and then U are eluted. The method can be applied to all aqueous solutions which do not contain strong complexing or precipitation agents for the elements considered.     

Chemometrics in pharmaceutical analysis

Chemometrics is now a well established discipline prompting independent research and development in its own right but, for their continuing success, chemometric developments must be relevant to the real needs of analysis. Pharmaceutical analysis, i.e., physical and chemical assessment of drugs and their dosage forms, needs more formal application of mathematical and statistical methods. The organisation of the laboratory, the development, optimization, assessment and interpretation of methods, and the evaluation of the data produced can all benefit from the application of chemometrics. Here, a selection of the more challenging problems facing the pharmaceutical analyst is presented, the potential for chemometrics is considered and some consequent implications for utilisation, against a background of control and regulation are discussed.     

UV–Vis spectroscopy with chemometric data treatment: an option for on-line control in nuclear industry

Chemometrics can be very useful for the classical field of UV–Vis determination of metals in aqueous solutions. A conventional approach consisting of using selective bands in a univariate mode is often not applicable to the real-world samples from e.g. hydrometallurgical processes, because of overlapping signals, light scattering on foreign particles, gas bubble formation, etc. And this is where chemometrics can do a good job. This paper overviews certain contributions to the field of multivariate data processing of UV–Vis spectra for seemingly simple case of metal detection in aqueous solutions. Special attention is given to applications in nuclear technology field.     

Characterization of purified <Superscript>241</Superscript>Am for common impurities by instrumental neutron activation analysis

Americium is an important actinide element having versatile applications based on its alpha and gamma emissions. Multi-element determination of radioactive samples using ICP-AES technique may be affected by the presence of americium due to its rich emission spectra. With a view to characterize plutonium based fuels containing americium for trace metals by ICP-AES technique accurately, a high purity ²⁴¹Am (using a separation procedure developed in our laboratory) was prepared. To ascertain its chemical purity it is essential to determine its impurity contents accurately. Instrumental neutron activation analysis (INAA), being a sensitive multi-elemental technique, was employed to determine the concentrations of impurities in purified ²⁴¹Am. Detection limits for the common elements and rare earth elements have also been determined. Comparison is made with the analytical data obtained by the ICP-AES method.     

Chemometrics in pharmaceutical analysis: an introduction, review, and future perspectives

Chemometrics is the application of statistical and mathematical methods to analytical data to permit maximum collection and extraction of useful information. The utility of chemometric techniques as tools enabling multidimensional calibration of selected spectroscopic, electrochemical, and chromatographic methods is demonstrated. Application of this approach mainly for interpretation of UV-Vis and near-IR (NIR) spectra, as well as for data obtained by other instrumental methods, makes identification and quantitative analysis of active substances in complex mixtures possible, especially in the analysis of pharmaceutical preparations present in the market. Such analytical work is carried out by the use of advanced chemical instruments and data processing, which has led to a need for advanced methods to design experiments, calibrate instruments, and analyze the resulting data. The purpose of this review is to describe various chemometric methods in combination with UV-Vis spectrophotometry, NIR spectroscopy, fluorescence spectroscopy, electroanalysis, chromatographic separation, and flow-injection analysis for the analysis of drugs in pharmaceutical preparations. Theoretical and practical aspects are described with pharmaceutical examples of chemometric applications. This review will concentrate on gaining an understanding of how chemometrics can be useful in the modern analytical laboratory. A selection of the most challenging problems faced in pharmaceutical analysis is presented, the potential for chemometrics is considered, and some consequent implications for utilization are discussed. The reader can refer to the citations wherever appropriate.     

杭州老虎洞窑古陶瓷成分的化学计量学研究

用支持向量机算法研究了与杭州老虎洞古陶瓷有关的两个断源、断代问题。作为化学计量学的～种新型分类算法,支持向量机在小样本问题上表现出良好的泛化能力,与特征选择方法结合,可以有效处理样本少,特征多的问题。本研究综合利用支持向量机、特征选择算法和其它化学计量学算法研究了杭州凤凰山麓万松岭附近的古窑遗址和“传世哥窑”的断源、断代问题,证明老虎洞窑与郊坛下窑产品截然不同,万松岭附近地面收集瓷片样本是老虎洞窑宋代地层的瓷片滑落所致,而“传世哥窑”样品可能是老虎洞窑元代时的产品。实验表明：支持向量机算法与化学分析相结合可以成为研究古陶瓷断源和断代问题的一种新方法。     

Rapid fusion method for determination of actinides in fecal samples

A new rapid fusion method for the determination of actinides in fecal samples has been developed at the Savannah River National Laboratory that can be used for emergency response or routine bioassay analyses. If a radiological dispersive device, improvised nuclear device or nuclear accident occur, there will be an urgent need for rapid analyses of environmental, food and bioassay matrices. If an inhalation event occurs and there is confirmed radionuclide activity present via urine analyses of individuals, fecal analyses will typically be required to determine the soluble/insoluble fraction of actinides present as a result of the event to allow a more reliable estimate of radiological dose. The new method for actinides in fecal samples uses accelerated furnace heating, a rapid sodium hydroxide fusion method, a lanthanum fluoride matrix removal step, and a column separation process with stacked TEVA, TRU and DGA resin cartridges. The rapid fusion method provides rugged digestion of any refractory particles present, essential for reliable analysis of actinides in fecal samples. Alpha spectrometry was used to determine the actinide isotopes, but this method can be adapted for assay by inductively-coupled plasma mass spectrometry for actinide isotopes with longer half-lives that have sufficient mass to allow measurement. The method showed high chemical recoveries and effective removal of interferences. The determination of actinides in fecal samples can be performed in less than 12 h in an emergency with excellent quality for emergency samples. The new method, which is much less tedious and time-consuming than other reported methods, can be used for emergency or routine fecal sample analyses. This enables more timely estimates of radiological dose to be performed that utilize soluble/insoluble actinide ratios.     

Sequential separation of neptunium,plutonium, americium and curium using coprecipitation with bismuth phosphate

The reaction of neptunium, plutonium and americium with oxidizing or reducing agents in phosphoric acid solution has been studied to design a separation procedure of the actinide elements using coprecipitation with bismuth phosphate. In the presence of uranium, successive separation of neptunium, plutonium, americium and curium was accomplished by combining the coprecipitation and redox reaction of the elements. The coprecipitation behaviour of fission products during the course of sequential separation of the actinide elements on bismuth phosphate was also discussed.