松香及其改性产品的红外光谱法快速鉴别

由于松香、马来松香、聚合松香、歧化松香和氢化松香及其酯等松香深加工产品外观相似,很难凭感官鉴别,给执法部门的监管和企业产品的质量控制造成很大困难。本文通过选用不同松香深加工产品作为研究对象,分类别比较其傅里叶红外光谱和二阶导数红外光谱,对其进行快速鉴别。研究表明:利用红外光谱和二阶导数红外光谱特征吸收峰的位置和吸收强度等差异信息可将它们快速准确鉴别。     

36种灵芝产品傅里叶变换红外光谱快速鉴别研究

利用傅里叶变换红外光谱法（FTIR）无损快速鉴别了36种灵芝类产品。灵芝、孢子粉和菌丝体的红外谱图差别较显著;不同厂家所生产的灵芝产品由于所选用灵芝的产地不同、所用辅料的种类以及辅料所添加的多少不同,均引起了谱图的相对峰强度和波数位置的改变。结果表明：36种灵芝产品均可以根据红外的特征谱图进行分类鉴别。该方法快速、不需对灵芝产品进行分离提取。     

傅里叶变换红外光谱和傅里叶变换拉曼光谱法无损鉴别药材的真伪

利用傅里叶变换红外（FT-IR）和近红外傅里叶变换拉曼（NIR FT-aman）光谱法对大黄（西宁大黄）与伪品大黄（华北大黄、山大黄、水根大黄）进行了无损快速的鉴别。结果表明：尽管正品大黄与伪品大黄差别较小，有大部分的化学成分有很大的相同之处，但在红外、拉曼谱图中各自的特征峰较突出，根据谱峰的强度和位置可容易地将它们区别开来。红外和拉曼光谱法相互印证，相互补充，具有快速、准确、操作简单、重复性好、不需对样品进行分离提取，可直接鉴别等特点。     

不同产地黄芪的红外光谱鉴别研究

采用红外光谱、二阶导数红外光谱和二维相关红外光谱,对四种不同产地的黄芪原药材进行了鉴别研究。结果表明:不同产地黄芪的红外光谱和二阶导数红外谱具有一定的相似度,与淀粉的红外谱图比对,4个不同产地的黄芪均含有淀粉,其中陕西绥德产黄芪的淀粉含量比其它3个产地黄芪的都要高。山西浑源和山西天镇产黄芪谱图的1 510、1 425cm-1木质素特征峰比内蒙古固阳和陕西绥德产黄芪的更为明显,说明前二者产黄芪中木质素含量高于后二者产黄芪。在二维相关红外谱图上,根据4个产地黄芪的相对峰强度的差异,可进行产地的鉴别。研究结果表明对于不同产地黄芪的鉴别,红外三级鉴定法是一种快速有效的新方法。     

红外指纹图谱与双指标模型结合用于白芷品质分析

利用共有峰率和变异峰率两个指标,鉴别了不同品质的白芷的红外指纹图谱,白芷样品按厂家各自聚为一类。并应用化学计量学中模式识别方法,即主成分分析和系统聚类分析法,对白芷样品共有特征高效液相色谱峰数据进行处理。主成分分析和系统聚类分析结果与双指标模型一致,川白芷与祁白芷共有峰率最高,达到83. 3%。运用红外指纹图谱与双指标模型结合的方法,可以对白芷进行简单快速准确鉴别,为白芷品质的评价提供了另一种思路。     

红外光谱法直接鉴别苦丁茶的研究

本文利用傅立叶变换红外光谱(FTIR)法快速、直接地测定了11种苦丁茶,并对所获得的指纹图谱进行特征峰指认和对比分析。结果表明:各种苦丁茶化学成分相同,而由于各成分间的相对含量的不同,使每种样品都有自己独特的红外谱图,不同产地、不同级别苦丁茶的红外吸收频率、吸收峰的相对强度都存在比较大的差异。同时还运用傅立叶变换红外光谱技术对不同产地、不同级别苦丁茶的混合化学体系进行了全组分快速分析,为苦丁茶的鉴别及质量控制提供了可靠的依据。     

傅里叶变换中红外光谱法检测脑胶质瘤

采用傅里叶变换衰减全反射中红外光谱法检测了19例液氮冻存的脑胶质瘤离体组织样品(星形细胞瘤10例, 少枝-星形细胞瘤9例), 对得到的红外光谱进行分析发现, 恶性程度不同的星形细胞瘤组织的红外光谱存在差异, 并且不同类型的脑胶质瘤组织的红外光谱也表现出较为明显的区别, 因此可以根据各个特征吸收峰的峰位、 峰形及谱峰强度等信息来区分脑胶质瘤, 并初步鉴别脑胶质瘤的性质. 研究结果表明, 通过某些特征吸收峰峰位的变化来鉴别星形细胞瘤和少枝-星形细胞瘤与病理诊断结果的符合率约为80%, 说明傅里叶变换衰减全反射中红外光谱法有望发展成为一种对样品无损伤、 快速的脑肿瘤诊断新方法.     

芦丁和槲皮素的几种快速鉴定方法

采用热分析(TA)、红外光谱法(FTIR)和X-射线衍射技术(XRD)对以槐米为原料制备的芦丁和槲皮素提取物进行了测定,通过分析二者谱图特征探讨快速鉴别这两种黄酮类化合物的方法。实验结果表明,芦丁的微商热重(DTG)曲线于278℃出现明显的热分解失重峰,差示扫描量热(DSC)曲线未出现明显相变峰;槲皮素的DTG曲线于349℃出现明显的失重峰,DSC曲线分别于323和361℃出现一个吸热峰和一个放热峰。红外谱图显示,3386 cm-1羟基伸缩振动吸收峰,1656 cm-1羰基伸缩振动吸收峰以及2931、1064、881 cm-1糖基的特征吸收峰可作为区分芦丁和槲皮素的标准峰。芦丁的X-射线衍射图谱呈多峰重叠的弥散峰,结晶度低;而槲皮素峰形明锐,结晶度高。因此,热分析、红外光谱及X-射线衍射技术可用于鉴别芦丁和槲皮素,相应谱图可作为它们各自的特征指纹图谱。     

红外三级鉴定法快速鉴别山豆根和北豆根

采用红外光谱三级鉴定法对山豆根和北豆根进行了鉴别研究。结果表明:山豆根和北豆根均含有饱和脂肪酸酯、芳香类化合物、黄酮类化合物和糖苷类化合物等物质。在一维红外光谱中,山豆根1 736、1 249cm-1和1 614、1 514、1 424cm-1峰的相对强度均比北豆根弱,说明山豆根中饱和脂肪酸酯成分、芳香类物质的含量低于北豆根。在高分辨率的二阶导数谱中,根据两者的差异可进一步发现山豆根和北豆根所含的饱和脂肪酸酯类成分存在差异,且北豆根中的芳香类物质含量比山豆根的高,而山豆根中淀粉的相对含量则高于北豆根。而二维相关红外光谱中,根据两者自动峰数目、位置和相对峰强度的差异,可进一步推断山豆根和北豆根所含的黄酮成分、糖苷类化合物是不一致的。因此,红外光谱三级鉴定法可为中药真伪鉴别提供一种快速、无损、整体、客观的方法。     

不同产地鲍鱼的FTIR谱图分析

为了寻找能够鉴别不同产地鲍鱼成分差异的新方法,利用傅里叶变换红外光谱(FTIR)测定不同产地的鲍鱼样品,对所获得的指纹图谱进行对比分析,初步探讨鲍鱼区域性之间的差别.结果表明:这3个产地鲍鱼红外吸收峰的峰数、峰位、峰形、峰强都存在一定程度的差异,为鉴别鲍鱼产地提供了一种有效的手段.     

近红外光谱法最小二乘双胞胎支持向量机的应用研究

依据中药大黄的近红外光谱信息,采用最小二乘双胞胎支持向量机( LSTSVM)算法,通过MATLAB软件编程,建立参数可优化识别模型,实现了对中药大黄的真伪鉴别.将实验材料98个大黄样品随机划分为训练集和测试集,对于训练集60个样品采用留1/5法交叉验证优化模型参数,以所选最优化参数结合训练集样品的近红外光谱建立最优识别模型,对测试集的38个样品的真伪迸行识别,识别率可达97.4％.结果表明,LSTSVM算法是一种有效的识别方法,可依据中药大黄的近红外光谱对其真伪进行快速识别.同时,本研究将大黄样品6次随机划分为训练集和测试集,建模预测平均识别率为93.4％,表明采用LSTSVM算法建立识别模型具有较好的稳健性.     

Infrared microspectroscopic identification of marker ingredients in the finished herbal products based on the inherent heterogeneity of natural medicines

Finished herbal products (FHPs) are preparations made from one or more herbs. The first stage in assuring the quality, safety, and efficacy of FHPs is to identify the herbs in the products. A new simple and quick method is developed in this research to detect the marker ingredients in FHPs. The inherent chemical heterogeneity of herbs and FHPs makes it possible to resolve different ingredients, without any additional separation or labeling, by infrared microspectroscopic imaging. Therefore, multiple marker ingredients in FHPs can be recognized directly and simultaneously by the infrared microspectroscopic identification method. As an example, all six kinds of herbs in Liuwei Dihuang Wan are identified through the following steps: (1) Each herb is characterized by infrared spectroscopic imaging, then the spectra of the main ingredients are calculated by the combination of principal component analysis, independent component analysis, and alternating least squares. (2) One marker ingredient is chosen for each herb. Ten typical pixels, the spectra of which best match the calculated spectrum of the marker ingredient, are selected by partial least squares target. The average spectrum of the typical pixels is taken as the marker spectrum. (3) Correlation coefficients between the typical pixel spectra and the marker spectrum are calculated. The acceptance correlation threshold is determined through the beta distribution function and then validated by positive and negative samples. (4) Using the above marker spectra and correlation criteria, herbs in the model mixture and the commercial product are identified. Good recognition results reveal the potential of the infrared microspectroscopic identification method in the quality control of herbs and FHPs.

Infrared spectroscopy of gas phase benzenium ions: protonated benzene and protonated toluene, from 750 to 3400 cm-1

Gas phase C 6H 7 (+) and C 7H 9 (+) ions are studied with infrared photodissociation spectroscopy (IRPD) and the method of rare gas tagging. The ions are produced in a pulsed electric discharge supersonic expansion source from benzene or toluene precursors. We observe exclusively the formation of either the C 2 v benzenium ion (protonated benzene) or the para isomer of the toluenium ion (protonated toluene). The infrared spectral signatures associated with each ion are established between 750 and 3400 cm (-1). Comparing the gas phase spectrum of the benzenium ion to the spectrum obtained in a superacid matrix [ Perkampus, H. H.; Baumgarten, E. Angew. Chem. Int. Ed. 1964, 3, 776 ], we find that the C 2 v structure of the gas phase species is minimally affected by the matrix environment. An intense band near 1610 cm (-1) is observed for both ions and is indicative of the allylic pi-electron density associated with the six membered ring in these systems. This spectral signature, also observed for alkyl substituted benzenium ions and protonated naphthalene, compares favorably with the interstellar, unidentified infrared emission band near 6.2 microm (1613 cm (-1)).     

商用聚丙烯酸类高吸水树脂粒子尺寸及分布与其凝胶浓度的关系

研究了6种商用聚丙烯酸类高吸水树脂(SAP)粒子尺寸大小及分布对其形成凝胶的临界浓度的影响,通过傅里叶变换红外光谱、X射线光电子能谱对样品的成分进行了分析,使用光学显微镜和ImageJ软件统计了样品未吸水时粒子的尺寸及分布,通过测定样品吸水后的膨胀比,估算得到了样品吸水后的粒子的尺寸及分布,用流变学方法和倒置实验法测定了高吸水树脂形成凝胶的临界浓度(凝胶点)。 结果表明,这6种商用聚丙烯酸类高吸水树脂吸水后的粒子的尺寸大小对其形成凝胶的临界浓度的影响不符合理论预测,这是由于粒子尺寸分布宽度不均一造成的。 在选择粒子大小分布占优的均一范围内,样品的凝胶浓度随着粒子尺寸的增大而降低。     

Multidimensional density operator propagations in open systems: model studies on vibrational relaxations and surface sticking processes

An efficient method for the numerical treatment of multidimensional dynamics of open systems is presented: the multiconfiguration time-dependent Hartree (MCTDH) method extended to the propagation of density operators. With this method we investigate the relaxation process of a CO molecule adsorbed on a copper surface, i.e., CO/Cu(100), after the excitation with an infrared (IR) pulse. The interaction potential was taken from the literature. Lifetime estimations and thermalization studies were performed on the IR excited CO molecule. We were able to treat this system with all six degrees of freedom (DOF) and thus 12 dynamical variables, but most of our studies used a two or four DOF model. Finally, we demonstrate the applicability of MCTDH to the analysis of scattering processes in an open environment. We calculate sticking coefficients of a scattered particle to a model surface, the latter acting as heat bath. The surface corrugation and the initial particle energy have been varied, and six different relaxation strengths have been studied. These calculations were done under the inclusion of three DOFs: the two surface coordinates and the distance between the particle and the surface.     

高效液相色谱法分析啤酒花浸膏中的6种酸性成分

建立了啤酒花浸膏中6种酸性成分(合葎草酮、葎草酮、加葎草酮、合蛇麻酮、蛇麻酮、加蛇麻酮)的高效液相色谱分析方法.分别考察了酸的加入、有机相种类及柱温对色谱分离效果的影响.在室温条件下,以Hypersil ODS2柱(250 mm ×4.6 mm,5 μm)为分析柱,以乙腈-0.1％(v/v)磷酸水溶液(pH 2.2)(...     

Application of algebraic method to the high overtones of C6H6 and C6D6

Both the spectra and infrared transition strengths of C₆H₆ and C₆D₆ for the C? H stretching overtones up to as high as v = 10 are described in high precision with few parameters (six for the spectra and four for the transition strengths) by the Iachello–Oss algebraic model. The Hamiltonian model is solved in the symmetry adapted bases, which are constructed by the symmetrized boson representation (SBR) technique. The results show that the combination of the algebraic method and SBR technique is a powerful method for describing vibrations of large molecules and high overtones. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2005     

Synthesis and characterization of some aromatic polyamides containing double bonds

Ten polyfumaramides based on fumaric acid and aromatic diamines and six polystilbenediamides based on 4,4′-stilbenedicarboxylic acid and aromatic diamines were synthesized and characterized by solubility, viscosity, density, infrared and UV-visible spectroscopy, and thermal analyses. Variation in properties with structure is discussed here.     

近红外光谱法快速测定附子中6个生物碱的含量

应用近红外光谱(NIRS)技术结合偏最小二乘(PLS)和最小二乘支持向量机(LS-SVM)建立了附子中多指标成分的快速无损检测方法。选取38批样品建立了同时测定附子样品中6种成分含量的高效液相色谱(HPLC)方法;通过采集附子样品的NIRS图,分别采用PLS和LS-SVM建立了各个成分HPLC测定值与NIRS图的定量校正模型。所建立的苯甲酰新乌头原碱、苯甲酰乌头原碱、苯甲酰次乌头原碱、新乌头碱、次乌头碱、乌头碱、单酯型生物碱总量和双酯型生物碱总量LS-SVM模型的相对预测偏差(RPD)分别为3.3、3.2、4.1、7.7、8.8、7.6、4.0和8.6;验证集相关系数(rpre)分别为0.9486、0.9475、0.9668、0.9909、0.9946、0.9969、0.9669和0.9927,且LS-SVM模型优于PLS模型,说明NIRS模型验证集与HPLC测定值具有良好的非线性关系,模型预测效果良好。采用NIRS技术结合LS-SVM模型可以快速对附子中的上述6个生物碱含量以及单酯型生物碱总量和双酯型生物碱总量进行检测,方法操作简便,对控制附子中的生物碱含量具有一定的指导作用。     

磁性氧化石墨烯固相萃取/高效液相色谱-串联质谱法测定环境水样中6种三嗪类除草剂残留

采用一步合成法制备磁性氧化石墨烯材料(GO-Fe_3O_4),将其用作磁性固相吸附剂对环境水样中的6种三嗪类除草剂进行萃取和富集,并与高效液相色谱-串联质谱法相结合进行测定。以扫描电镜和傅立叶红外光谱对合成材料进行了表征,并考察了GO-Fe_3O_4用量、萃取时间、水样的pH值及离子强度和解吸条件等因素对萃取效率的影响。6种三嗪类除草剂的检出限为0.1~1.0 ng/L,富集倍数可达616~902倍。将方法应用于苏州地区太湖水、运河水和护城河水等实际水样的分析,加标回收率为85.4%~117.6%,相对标准偏差为1.2%~10.0%。该方法操作简单快速,富集倍数较高,检出限低,可用于水样中痕量三嗪类除草剂残留的检测。