人血清白蛋白与酸性铬兰K相互作用机理的光谱学

人血清白蛋白;酸性铬兰K;荧光光谱法;傅立叶变换红外光谱;二级结构     

大气毒物傅立叶变换红外光谱差减定量数据库的建立

本文在总结大气毒物红外吸收光谱规律和初中经验基础上，提出了确定大气毒物傅立叶变换红外光谱差减定量谱线的六条原则，并建立了光谱差减定量数据库，可供大气毒物傅立叶变换红外光谱自动定量分析实时咨询使用。     

蒙药草乌花及其提取物化学成分的红外光谱法整体结构解析

采用傅立叶变换红外光谱法并借助于二阶导数谱以及二维相关红外光谱(2D-FTIR)研究了蒙药草乌花原药材及不同溶剂提取物(依次采用乙醚,乙醇和水提取)所含化学成分的红外谱图整体变化规律.结果显示:在草乌花原药材中具有明显的多糖类化合物的红外特征吸收峰,证明该药材中含有大量多糖类成分.草乌花药材乙醚和醇提物的红外光谱较相似...     

丁咯地尔与人血清白蛋白结合的光谱学研究

用紫外吸收光谱法、荧光光谱法和傅立叶变换红外光谱法探讨了在模拟人体生理条件下,丁咯地尔与人血清白蛋白(HSA)的结合模式.结果表明:丁咯地尔对HSA的内源荧光有显著的猝灭作用,且猝灭机理主要为静态猝灭.丁咯地尔与HSA形成了1 ∶ 1的复合物,结合常数K=7.43×102 L·mol-1(308 K).根据Fster偶极-偶极非辐射能量转移机理,求得丁咯地尔与HSA间的结合距离r=2.64 nm.由热力学参数确定其作用力以氢键和范德华力为主.同步荧光和傅立叶变换红外光谱表明丁咯地尔对HSA二级结构的含量产生影响,使HSA的α-螺旋结构的含量明显降低,β-折叠和β-转角结构的含量增加.     

鞋底材料的傅立叶变换红外光谱类型分析

利用傅立叶变换红外光谱技术对收集的29种皮鞋类黑色鞋底样品进行了测定分析,其中24种样品来自不同品牌或型号,5种样品来自同一品牌同一厂家同一批次.从红外光谱图中可以看出,依据红外光谱图中特征峰的峰数、峰位、峰形可将29个鞋底样品分为3大类.同一大类的部分鞋底样品有着相似的红外光谱特征,但在相对峰高比和指纹区中一些弱吸收峰上仍然存在明显差异.同一品牌同一厂家同一批次的鞋底样品红外光谱特征基本一致.这表明傅立叶变换红外光谱法是鉴别鞋底材料的有效方法,可以为案件现场遗留的各种鞋底材料残渣及其擦痕提供种属鉴别及比对分析.     

分析测试新成果(238~242)电线塑料护套的傅立叶变换红外光谱分析

采用傅立叶变换红外光谱法对21个5种不同颜色的电线塑料护套样品进行了分析.从红外光谱图中可观察到样品特征峰的峰数、峰位、相对峰面积比均有差异,但可以归纳为两大类.其中同种颜色的不同样品在红外谱图中又反映出了不同的信息,这表明在外观颜色十分相近的情况下,采用此方法能够有效的为刑事案件现场遗留的各种塑料制品提供鉴别与比对.     

润滑油中抗氧抗腐剂与丁二酰亚胺含量的测定

应用傅立叶变换红外光谱法测定润滑油中抗氧抗腐剂(ZDDP)、丁二酰亚胺的含量。采用基线法计算其吸光度,选定667cm-1为ZDDP定量吸收峰,1706cm-1为丁二酰亚胺定量吸收峰,它们都符合比耳定律,该方法适宜新旧润滑油中ZDDP、丁二酰亚胺的定量分析。     

傅立叶变换红外光谱法对聚氯乙烯及邻苯二甲酸酯类增塑剂的快速鉴定

应用傅立叶变换红外光谱法实现了聚氯乙烯及邻苯二甲酸酯类增塑剂的快速鉴别。对聚氯乙烯的定性采用了衰减全反射技术,用锗作为晶体材料,对邻苯二甲酸酯类的定性则采用透射法。用溶解-沉淀法对试样进行分离和纯化,所用溶剂为四氢呋喃,沉淀剂为无水乙醇。经过此方法,聚合物与增塑剂达到很好的分离和纯化。     

CCQM-K74国际比对中二氧化氮浓度的测量

介绍了国际比对样品中10μmol/mol NO2气体浓度精确分析方法的建立过程。该方法的建立包括标准物质的制备、分析仪器的选择和测量结果的不确定度3个主要的方面。标准物质的制备及其量值的不确定度评价采用了气体标准物质定值的基准方法——称量法。对傅立叶变换红外光谱法(FTIR)和化学发光光谱法进行了比较研究。确定了更适合于本次国际比对样品的分析方法为化学发光光谱法,测量结果的相对扩展不确定度为1.0%(k=2)。本次比对的最终结果报告显示,所建立的分析方法准确可靠。     

傅立叶红外光谱法测定丙烯-乙烯共聚物中丙烯单元含量

应用傅立叶红外光谱法,根据丙烯-乙烯共聚物的红外特征性,寻找较好的峰位,使用通用型制膜机制得厚度均匀一致的膜片,制作标准曲线,建立了快速检测丙烯-乙烯共聚物中丙烯单元含量的方法。将红外光谱法分析结果与核磁共振法分析结果进行比较,相对误差在2%以内,测得不同丙烯单元含量的样品的相对标准偏差(n=6)为0.47%~1.1%。     

FT-IR surface analysis of poly [(4-hydroxybenzoic)-ran-(2-hydroxy-6-naphthoic acid)] fiber – A short review

Instrumental techniques such as Fourier Transform Infrared Spectroscopy (FT-IR) constitute well-studied methodologies for polymer characterization, including polymeric fibers. However, a relatively short number of scientific publications involve the characterization of commercial Poly [(4-hydroxybenzoic)-ran-(2-hydroxy-6-naphthoic acid)] (Vectran™) fiber and its surface species. The majority of the published infrared studies uses the medium infrared region (MIR) associated to the Attenuated total reflection (ATR) method. In this scenario, this short review addresses the characteristics of Vectran™ fiber, sample depth data of each FT-IR spectrum mode, reflection and photo-acoustic spectroscopy (PAS), including near infrared (NIR) analysis. This paper addresses also researches on the characterization of Vectran™ by several FT-IR analysis conditions aiming to contribute to future studies. This brief review deals with methodologies developed in the last decade and published by several scientific research groups, emphasizing studies conducted in the last five years. A critical assessment and trends are also included.     

On-line analysis of polymer melt processes

Molten polymer process streams are difficult to analyze either in- or on-line because of sampling problems due to the high temperature and viscosity of the molten state. Real-time monitoring of chemical compositions in these processes can significantly improve safety and product quality and minimize process costs and waste. The information content of the mid-infrared spectrum combined with the recent development of rugged process Fourier transform (FT) IR spectrometers is stimulating the application of process FT-IR to industrial polymer melt processes. Sampling considerations for polymer melts are reviewed. Also, the use of FT-IR spectrometry for on-line measurements of the polymer composition for polymer blends and copolymers in the melt, and the question of how this information could be used to monitor and control the quality of the product given by the process are discussed.     

Nanocomposite Fibers for Cosmetotextile Applications

In this work, a series of nylon 6 nanocomposites with different nanoclay/jojoba oil contents have been prepared by direct melt compounding. Nanocomposite morphologies were characterized by means of WAXS analysis. Thermal and mechanical fibers properties were studied as well. The kinetic desorption of the cosmetic oil through the polymer matrix was evaluated by FT-IR microscopy. It was found that the state of the clay particles affected the thermal behaviour and the tensile mechanical properties of each polymer/clay hybrid. On the other hand, the release of the cosmetic oil, tested by FT-IR microscopy, is a good perspective for the application of polyamide 6 nanocomposite fibers as textiles in cosmetic field.     

Multitechnique spectroscopic analysis of polymer surfaces

The analysis of polymeric materials by modern surface sensitive spectroscopic experiments has yielded results which can be useful in solving both fundamental structural questions and problems which arise with the use of working materials. This paper will review the developments in polymer surface analysis which utilize the techniques of X-ray photoelectron spectroscopy (XPS or ESCA), secondary ion mass spectrometry (SIMS), ion scattering spectrometry (ISS), and fourier transform IR (FT-IR) spectroscopy stressing the complementary nature of the information derived from these methods.     

傅里叶变换-红外光谱法快速测定面粉中滑石粉

提出了应用衰减全反射(ATR)傅里叶变换-红外光谱(FT-IRS)法快速检测面粉中混入的滑石粉,测定中采用中红外检测器。根据滑石粉的标准红外光谱图并为避免面粉的吸收干扰,选择滑石粉在3 674.96 cm-1及668.16 cm-1两处的特征吸收峰作为判定面粉中是否含有滑石粉的依据,并且其吸收强度随滑石粉含量的增加而增加。由于面粉中滑石粉质量分数低于0.5%和0.2%时,分别在上述两吸收峰波长处已不呈现吸收,方法中将1%(质量分数)作为滑石粉的检出限。此外,根据吸收峰的吸收强度可估算出滑石粉的含量。方法中选用的主要仪器工作条件为:①扫描范围为4 000～650 cm-1;②分辨率为8 cm-1;③扫描信号累加次数为32;④衰减全反射压力常数为100。     

活性铽三元荧光配合物的合成、表征及性能研究

本文以对甲基苯甲酸、对氨基苯甲酸、磺基水杨酸、大茴香酸、间氯苯甲酸为第一配体,丙烯腈为活性配体,合成了五种新的铽芳香羧酸丙烯腈三元配合物。通过元素分析,EDTA配位滴定分析,热分析,红外、紫外、荧光光谱分析对目标配合物的组成、结构进行了表征,并研究了它们的发光性能。结果表明,五种新的活性铽三元配合物均具有良好的发光性能,各芳香羧酸向铽离子传递光能的动力为:大茴香酸>对甲基苯甲酸>间氯苯甲酸>磺基水杨酸>对氨基苯甲酸,将这些含活性配体丙烯腈的发光铽配合物引入高分子化合物中可望合成出键合型铽高分子发光材料。     

Synthesis and photochemical properties of poly(2,5-dimethoxy-p-phenylenevinylene) hosted in the intergallery spaces of montmorillonite

Poly(2,5-dimethoxy-p-phenylenevinylene) (dMeOPPV) has been formed in the intergallery spacing of a montmorillonite by introducing the (2,5-dimethoxy-1,4-phenylene)bis(methylene-S-tetrahydrothiophenium) monomer by ion exchange, increasing the basicity of the solid aluminosilicate with Cs(+) and subsequent heating at 200 degrees C. dMeOPPV@montmorillonite was characterized by optical spectroscopy, FT-IR spectroscopy, solid-state (13)C NMR, photoluminescence, and chemical analysis. All the data are compatible with that reported in the literature for pure dMeOPPV. The dMeOPPV polymer incorporated inside montmorillonite exhibits a green light emission which makes the organic polymer very attractive for its application in polymer light-emitting diodes (PLEDs). The new polymeric material can be submitted to laser irradiation (laser power, 10 mJ pulse(-1)) under oxygen without decomposition.     

Flow-through enzymatic reactors using polymer monoliths: From motivation to application

The application of monolithic materials as carriers for enzymes has rapidly expanded to the realization of flow-through analysis and bioconversion processes. This expansion is partly attributed to the absence from diffusion limitation in many monoliths-based enzyme reactors. Particularly, the relatively ease of introducing functional groups renders polymer monoliths attractive as enzyme carriers. After summarizing the motivation to develop enzymatic reactors using polymer monoliths, this review reports the most recent applications of such reactors. Besides, the present review focuses on the crucial characteristics of polymer monoliths affecting the immobilization of enzymes and the processing parameters dictating the performance of the resulting enzymatic reactors. This review is intended to provide a guideline for designing and applying flow-through enzymatic reactors using polymer monoliths.     

Use of FT-IR Spectrometry for On-Line Detection in Temperature Rising Elution Fractionation

Summary: Temperature rising elution fractionation (TREF) has become a popular analytical technique that is able to determine the chemical composition distribution (CCD) of an ethylene/α-olefin copolymer. An infrared (IR) detector is commonly used in TREF detection to measure the concentration of the polymer solution exiting the column as a function of elution temperature. The chemical composition of the eluting polymer at a given elution temperature can be predicted from the relationship between comonomer content and TREF elution temperature pre-established through ¹³C nuclear magnetic resonance (NMR) analysis of TREF fractions. In this article, a Fourier transform infrared (FT-IR) spectrometer has been coupled with a TREF instrument to provide a more powerful tool for characterizing complex olefin copolymers. The Partial Least Squares (PLS) technique is used when analyzing the FT-IR spectra of the eluting polymer solutions. The power of on-line FT-IR detection in TREF is demonstrated using a few complex copolymer systems, such as ethylene-octene copolymer, polystyrene grafted ethylene-vinyl acetate copolymer and ethylene-methyl acrylate copolymer.     

FT-IR/UATR and FT-IR transmission quantitative analysis of PBT/PC blends

Polymer blends are produced to achieve properties that pure polymers are unable to. The qualitative analysis of these blends is not always satisfactory to point out failures in the final product and, therefore, the determination of their content might be required. The aim of this study is to develop quantitative methodologies using Fourier transform infrared spectroscopy (FT-IR), reflection mode with the universal attenuated total reflectance accessory (UATR) and transmission techniques, for the determination of the content of each polymer present in the polymer blend poly (butylene terephthalate) (PBT) and polycarbonate (PC). FT-IR/UATR presented better results using the relative band (A₁₇₇₂/A₁₇₁₆). FT-IR/UATR presented error of 2.30%, which is a little higher than the accuracy limit of the spectrometer (≤2%), but still adequate for industrial applications.