全反射红外逐层检测含重氮高分子薄膜的生长

运用全反射红外技术对逐层组装的含重氮高分子薄膜进行了分步定量分析.利用－CH2－峰的逐层变化规律,确认了在组装过程中每层吸附高分子的量是一致的.通过重氮基－N≡N＋特征的吸收峰,定量计算了在特定实验条件下,－N≡N＋分解生成共价键的比例.这些结果为认识重氮高分子薄膜的生长提供了更为直接和细致的信息.     

傅立叶变换激光腔内吸收光谱方法研究吸收谱线的强度与线形

Based on Fourier-transform intra-cavity laser absorption spectroscopy (FT-ICLAS) setup reported, a signal differential module is introduced to reduce the noise rising from the fluctuation of the laser power and to improve the quality of the interferogram obtained in the experiment. The capability to do quantitative measurement was demonstrated by recording the atmospheric oxygen absorption near 760 nm. The v=6 local mode stretching overtone spectra of phosphine were recorded with different sample pressure. The pressure caused self-broadening and line shift parameters of this band were achieved.     

傅立叶变换离子回旋共振质谱及其研究进展

本文综述了傅立叶变换离子回旋共振质谱的基本原理及其颇具特色的数据处理方法.以两种典型的离子化方法为代表,介绍了目前主要使用的离子源,并总结了该方法在分析科学,尤其是在大分子分析、气相离子反应动力学研究和复杂体系分析等领域中的广泛应用.     

Acidichromism in the Mixed Langmuir—Blodgett Films of Stearic Acid with a Carbazole—containing Schiff Base

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Effect of the Esters of Gallic Acid on Model and Human Blood Platelet Membranes Studied by Fourier Transform Infrared Spectroscopy

Gallic acid is one of the components of Chinese herbal drug Radix paeoniae used for promoting blood circulation to remove blood stasis. This paper studied the effects of gallic acid and its esters (e.g. ethyl, propyl, isobutyl and butyl gallate) on model and human blood platelet membranes by FTIR which was used for monitoring the physical state of the acyl chain, interfacial and head group region of the membrane lipid bilayer. From the experimental results it can be seen that the gallic acid and its esters have the modifying function on the pure and cholesterol-containing DPPC model membranes, and have the quantity-effective and structural-effective relationships. In addition, it is discovered that these esters have the modifying effect on the structure of human blood platelet membrane and can reverse the effect of ADP. That the effect of the esters of gallic acid counteracts the effect of cholesterol and ADP on human blood platelet perhaps provides a new explanation of the mechanism of Chinese herbal d     

Early Diagnosis of Mercury Stress of Wheat Seedlings Using Attenuated Total Reflection Fourier Transform Infrared Spectroscopy

The aim of the study was the non-destructive and rapid evaluation of the phytotoxicity of different concentrations of mercury (0.2, 0.4, 0.6, 0.8, and 1?mM) on the biochemical profile of wheat seedlings using attenuated total reflectance–Fourier transform infrared (ATR–FTIR) spectroscopy in combination with principal component analysis. Infrared spectra of the leaves of control and mercury-treated wheat seedlings were recorded in the spectral region from 4000 to 485?cm^?1. The preprocessing of the recorded spectra by second derivation enhanced the specificity of the infrared bands. The area of the bands estimated by curve fitting was used for the relative quantitative estimation of the biochemical changes involved. The principal component analysis of the acquired spectral measurements discriminated between the biochemicals of the control and mercury-treated wheat seedlings. The result showed that mercury (0.2–1?mM) significantly enhanced the content of the cell wall polysaccharides, amino acids, β-sheet component of proteins, and lipids in the leaves accompanied by reduction in the amount of α-helix. The change in β-sheet/α-helix ratio indicated mercury induced structural changes in the secondary structure of proteins. The increase in the levels of methylene bands and carboxyl bands indicates changes in lipid configuration and peroxidative damage caused by mercury. The results of this study demonstrate the potential of ATR–FTIR in combination with principal component analysis as an environmental monitoring tool for the identification of plant populations affected by environmental factors like heavy metal stress prior to the appearance of visual signs of toxicity.     

Detecting Aflatoxin B1 in Peanuts by Fourier Transform Near-Infrared Transmission and Diffuse Reflection Spectroscopy

Aflatioxin B₁ (AFB₁) has been recognized by the International Agency of Research on Cancer as a group 1 carcinogen in animals and humans. A fast, batch, and real-time control and no chemical pollution method was developed for the discrimination and quantification prediction of AFB₁-infected peanuts by applying Fourier transform near-infrared (FT-NIR) coupled with chemometrics. Initially, the near-infrared transmission (NIRT) and diffuse reflection (NIRR) modules were applied to collect spectra of the samples. The principal component analysis (PCA) method was employed to extract the characteristic wavelength, followed by different preprocessing methods (seven methods) to build an effective linear discriminant analysis (LDA) classification and partial least squares (PLS) quantification models. The results showed that, for both the NIRT or NIRR modules, the LDA classification models satisfactorily distinguished peanuts infected with AFB₁ or from those not infected, with external validation showing a 100% correct identification rate and a 0% misjudgment rate. In addition, combined with the concentration of AFB₁ in peanuts determined by enzyme-linked immunoassay assay, the best partial least squares (PLS) models were established, with a combination of the first derivative and the Norris derivative filter smoothing pretreatment (R_c² = 0.937 and 0.984, RMSECV = 3.92% and 2.22%, RPD = 3.98 and 7.91 for NIRR and NIRT, respectively). The correlation coefficient between the predicted value and the reference value in the external verification was 0.998 and 0.917, respectively. This study highlights that both spectral acquisition modules meet the requirements of online, rapid, and accurate identification of peanut AFB₁ infection in the early stages.     

Rapid Diagnosis of Type II Diabetes Using Fourier Transform Mid-Infrared Attenuated Total Reflection Spectroscopy Combined with Support Vector Machine

Type II diabetes was diagnosed by Fourier transform mid-infrared (FTMIR) attenuated total reflection (ATR) spectroscopy in combination with support vector machine (SVM). Spectra of serum samples from 65 patients with clinical confirmed type II diabetes mellitus and 55 healthy volunteers were acquired using ATR-FTMIR and were first pretreated by three pretreatments (Savitzky–Golay smoothing, multiple scattering correction, and wavelet transforms algorithms) to reduce the interfering information before establishing the SVM models. The parameters of SVM (penalty factor C and kernel function parameter gamma) were optimized to improve the generalization abilities of the models. A grid search method (GS), genetic algorithm (GA), and particle swarm optimization (PSO) algorithm, were used to find out the optimal parameter values. The results showed that the maximum accuracies were 95.74, 97.87, and 89.36% for the optimized GS, GA, and PSO algorithms. The maximum sensitivities were 96, 100, and 92, and the maximum specificity were 95.45, 95.45, and 86.36%, respectively. The results indicated that the accuracy of type II diabetes was improved using the GS, GA, and PSO algorithms for optimizing the SVM parameters. The GA was found to be slightly better than the GS and PSO. The results of the experiment confirmed that the combination of the ATR-FTMIR spectroscopy and SVM was able to rapidly and accurately diagnose type II diabetes without reagents.     

漫反射傅里叶变换红外光谱法测定维生素C制剂中抗坏血酸的含量

采用漫反射傅里叶变换红外光谱法(DRIFTS)测定维生素C制剂中抗坏血酸的含量。选择合适的分析峰1660~1680 cm–1,可排除其它成分的影响,吸光度与抗坏血酸的浓度呈良好线性关系。以镜面为背景,以75μm筛过筛后的KBr为稀释剂,用DRIFTS法分别测定了3种市售维生素C制剂中的抗坏血酸含量,测定结果分别为75.60%,9.80%,6.72%;相对标准偏差(n=6)分别为6.6%,4.9%,8.2%,与碘量法测定结果接近。样品加标回收率为94.0%。DRIFTS法测定维生素C中的抗坏血酸方法简便、准确,无试剂消耗,无废液产生,是非破坏和非污染的绿色分析方法。但其测定结果的精密度不如碘量法,而且其测定结果的准确程度受样品的性状限制,对于白色粉末或可研磨为粉末的样品分析结果准确度较高。     

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。     

傅立叶变换拉曼光谱和红外光谱鉴别塑料

用傅立叶变换拉曼光谱、衰减全反射红外光谱和近红外光谱结合OPUS/Ident软件对添加不同填料、不同助剂的塑料进行鉴别分类。结果表明:分子光谱结合化学计量学鉴别塑料是一种快速可靠的方法。其中拉曼光谱和衰减全反射红外光谱能够直接区分样品,而近红外光谱非常类似,不能直接区分。但是用OPUS/Ident软件中的W ard算法处理这3种光谱后,得到的树形图能够将样品准确分类。     

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.     

嵌段共聚物傅里叶变换拉曼光谱

用傅里叶变换拉曼光谱(FT-Paman)研究了聚环氧乙烷-聚环氧丙烷-聚环氧乙烷(PEO-PPO-PEO)嵌段共聚物的无水样品,发现某些谱带对PEO0-PPO-PEO嵌段共聚物的结构和构象变化敏感,其中某些峰的相对强度的PPO/PEO比率和共聚物的构象有关,研究表明PluronicF68和F88具有一些反式构象的螺旋结构,PluronicP103(P123)是无规则结构,其它的嵌段共聚物处于二者之间.     

苦味酸碳酰肼、苦味酸氨基脲和苦味酸氨基胍的温度跃升傅里叶变换红外光谱

利用温度跃升傅里叶变换红外原位分析技术(T-jump/FTIR)对苦味酸碳酰肼,苦味酸氨基脲和苦味酸氨基胍的快速热分解过程进行了研究,利用快速扫描傅里叶变换红外光谱在线检测气相产物的种类及浓度变化趋势。研究发现,在0.1 MPa氩气气氛下,这3种化合物快速热分解过程的含氮气相产物主要有NO、NH3、HCN、NO2、HONO和HNCO,含碳气相产物主要有CO2、CO、HCN、HNCO和HONO,NH3可进一步氧化为NO2,N2O和H2O等产物;实验同时得到了快速热分解主要气相产物摩尔分数随时间的变化关系曲线。研究表明,苦味酸氨基脲作为新型、安全、环保起爆药剂和汽车安全气囊产气剂组分有很好的发展前景。     

用傅里叶变换红外光谱测定汽油有关性质

用傅里叶变换红外光谱仪（FTIR）,在1550－660cm^-1波数范围内,采用化学计量学的偏最小二乘法（PLS）,测定汽油的辛烷值（RON）、密度、馏程（50％、90％）、芳烃、烯烃等质量性质。 试验结果表明,实验室标准方法测定的真值和红外光谱预测值的相关性好,检验结果符合国家标准方法的再现性要求。     

傅里叶变换红外光谱和核磁共振法对土壤中腐殖酸的表征

采用氢氧化钠碱提法提取和纯化了我国４种典型土壤中腐殖酸,分别用元素分析、傅里叶变换红外光谱（ＦＴＩＲ）、固仿核磁共振（ＮＭＲ）等方法对提取腐殖酸进行了表征。结果表明,４种土壤中腐殖酸原ＦＴＩＲ图谱相似,含有相同类型的官能团。对ＮＭＲ不同化学位移域的谱峰积分获得４种土壤腐殖酸的各组成比例,组成中以烷氧基Ｃ的含量最高,脂类Ｃ略高于芳香Ｃ含量。     

抗坏血酸升温氧化过程的二维相关红外光谱分析

采用傅里叶变换红外光谱法 (FTIR)和二维相关分析 (2DCorrelationAnalysis)技术研究了固态抗坏血酸在 2 0℃～ 1 60℃的升温氧化过程。结果表明 :抗坏血酸随着温度升高的红外光谱的特征峰在一维图上变化不明显。借助于二维相关分析 ,不仅提高了谱图的分辨率 ,将一维红外谱图上 1 674cm- 1 处的单峰分解为两个自相关峰 ,显示了抗坏血酸的互变异构体中酮式结构的CO基团和醇式结构的CC基团的振动 ;还揭示了分子内各官能团之间的相互作用 ,反映了在升温氧化过程中这些基团之间的协同关系和变化的先后顺序。抗坏血酸分子中CO、CC和COC基团发生了相互作用 ,其变化的顺序是CC先于COC发生偶极矩的变化 ,最后是CO发生变化 ,此现象与抗坏血酸的氧化反应机理相一致。总之 ,二维相关红外分析可以作为研究抗坏血酸升温氧化过程中结构动态变化的一种新方法 ,也为抗坏血酸在氧化过程中的机理研究提供了一个重要的理论依据。     

Adsorption Behavior of a Water-soluble Porphyrin at the Glass-water Interface as Studied by Synchronous Total Internal Reflection Fluorescence Spectroscopy

Total imernal reflection fluorescence spectroscopy (TIRF) and synchronous scanning technique were combined to study the adsorption behavior of the meso-tetrakis (4-sulfonatophenyl)porphyrin (TPPS) at the glass-water interface without any surfactant. The pH dependence of synchronous fluorescence signal at the interface was analyzed. Both unprotonated (TPPS^4-) and diprotonated (H2TPPS^2-) forms of TPPS were observed at the interface. But the interface favored the adsorption of. The apparent estimated pKa2 value shifted from 5.00 in the bulk solution to 2.7 at the interface. STIRF provides a good technique to study multi-component systems at the interface.     

Characterization of the Release of Urea from Coated Fertilizer by Fourier Transform Infrared Spectroscopy with Attenuated Total Reflectance

The development of a simple and cost-effective method for the determination of the release of coated urea has significant implications. Fourier-transform infrared spectroscopy with attenuated total reflectance was employed to determine the release of urea through univariate and multivariate calibration. The results indicated that univariate calibration did not accurately predict the release of urea, whereas partial least squares based on multivariate calibration performed significantly better. Partial least squares had the highest accuracy when the band located at 1420–1520 per centimeter was employed as the input. Moreover, the accuracy was further improved when segmented partial least squares models were developed at low and high urea concentrations. Unsegmented and segmented partial least squares models were employed, and release values were comparable to those measured by colorimetry. This work demonstrated the use of infrared spectroscopy and partial least squares to characterize the release of coated urea.