Measurements of (18)O-Enriched Ozone Isotopomer Abundances Using High-Resolution Fourier Transform Far-IR Spectroscopy

The distribution of ozone isotopomers in ozone mixtures produced by electric discharge in mixtures of (16)O(2) and (18)O(2) at 77 K was measured by high-resolution FTIR spectroscopy. It was of key importance to assess not only the total amount of isotopomers of a certain mass but also the relative amounts of corresponding asymmetric and symmetric ozone species of the same mass given as the ratios [(16)O(16)O(18)O]/[(16)O(18)O(16)O] and [(16)O(18)O(18)O]/[(18)O(16)O(18)O]. For many purposes both ratios have been assumed to have the statistical value 2.00. Pure rotational spectra in the far-IR region (30-100 cm(-1)) were recorded for three different (18)O-enriched ozone mixtures, all at 0.00185 cm(-1) resolution. All the spectra were corrected for thermal emission. Linestrengths for individual lines in a particular spectrum were measured by means of a fitting technique taking into account contributions from all other lines in the spectrum. For this purpose theoretical linestrengths for all six ozone species containing (16)O and (18)O obtained from a quantum-number-dependent dipole operator were used. The ratios between observed and theoretical linestrengths were used to determine the abundances of individual isotopomers in a particular ozone mixture. For one of the ozone samples the abundances of all six ozone species were determined within 1% relative uncertainty. For the three ozone mixtures studied, the ratio between asymmetric and symmetric species of mono-(18)O ozone were determined to 1.99(2), 2.01(2), and 2.10(6). The ratio between asymmetric and symmetric species of di-(18)O ozone were determined to 2.51(4), 2.42(10), and 2.46(3). Copyright 2000 Academic Press.     

High-Resolution Fourier Transform Spectroscopy of Three Near-Infrared Transitions of NiF

The emission spectrum of the NiF radical has been recorded by high-resolution Fourier transform spectroscopy in the region 6000-12 000 cm⁻¹. Numerous new near-infrared bands were observed. In this paper three electronic transitions are analyzed leading to the identification of two new electronic states: a [12.0]²Φ_7/2 state and a [11.1]²Π_3/2 state located, respectively, at 12 008.89 and 11 096.05 cm⁻¹ above the X²Π_3/2 ground state. These electronic states can be correlated to the [3d⁸(³F)4s]²F atomic term of Ni⁺ as predicted by Carette et al. [J. Mol. Spectrosc.161, 323-335 (1993)].     

High-Resolution Survey of the Visible Spectrum of NiF by Fourier Transform Spectroscopy

High-resolution spectra of NiF have been recorded in emission by Fourier transform spectroscopy using a very stable discharge source. The 0-0 bands of 14 electronic transitions have been studied, 6 of them for the first time. This work confirms the presence of 5 low-lying spin components X²Π_3/2, [0.25]²Σ⁺, [0.83]A²Δ_5/2, [1.5]B²Σ⁺, and [2.2]A²Δ_3/2 as known from previous laser-induced fluorescence experiments. Eight electronic states are now identified in the 18 000-24 000 cm⁻¹ range above the ground X²Π_3/2 state. Electronic assignments for these excited states are not always obvious because of violations of the selection rules and unusual fine structure parameters. We think that some of the upper states are spin components of quartet states. In such a congested spectrum, high-resolution spectra are best analyzed in conjunction with an energy level diagram constructed mainly by dispersed low resolution laser-induced fluorescence.     

FTIR结合主成分分析对棕榈科植物鉴别研究

采用傅里叶变换红外光谱(FTIR)结合主成分分析(PCA)对棕榈科植物2个亚科4个族的植物叶片进行了光谱研究。结果显示,棕榈科同族不同种和同科不同族的植物在红外光谱上表现出差异。用二阶导数光谱进行主成分分析,显示可以将样品进行正确分类。研究表明傅里叶变换红外光谱在鉴别分类植物方面具有应用潜力。     

Fourier Transform Polarization Spectroscopy

Abstract

The transmission and reflection properties (optical response) of systems of homogeneous phases a r e determined by their optical constants and the system geometry. Given such information, the optical response of a system can always be calculated in principle, and for simple geometries fairly readily in practice. The problem arises in attempting to icvert this process and determine the optical constants (and sometimes the geometry as well) from measurements of the optical response. This article reviews recent developments in the determination of the spectra of the optical constants of both isotropic and linearly anisotropic condensed phases and thin films via Fourier transform (Ft) spectroscopy.     

High-Resolution Fourier Transform Emission Spectroscopy of the TiCl Radical in the 420-nm Region

Emission spectra of the TiCl radical in the 420-nm region have been observed at a resolution of 0.04 cm(-1) using a Fourier transform spectrometer. A new electronic assignment of (4)Gamma-X(4)Phi has been proposed. Rotational analysis has been provided for the 0-0 and 1-1 vibrational bands of the (4)Gamma(5/2)-X(4)Phi(3/2) and (4)Gamma(7/2)-X(4)Phi(5/2) spin components and the 0-0 band of (4)Gamma(9/2)-X(4)Phi(7/2). Copyright 2000 Academic Press.     

八种鹅膏菌的傅里叶变换红外光谱的差谱鉴别研究

利用傅里叶变换红外光谱技术对长柄鹅膏菌、粗鳞白鹅膏菌、格纹鹅膏菌、红黄鹅膏菌、黄柄鹅膏菌、灰疣鹅膏菌、欧氏鹅膏菌、小豹斑鹅膏菌进行傅里叶变换红外光谱研究, 发现八种鹅膏菌的傅里叶变换红外光谱极为相似, 特征区和指纹区(1800~1100 cm-1)的相关系数均大于0.966。因此从这八种鹅膏菌的原始光谱对其鉴别将十分困难。通过差谱技术处理后, 八种鹅膏菌在1800~1100 cm-1范围呈现出各自的特征, 相关分析结果定量反映出它们之间差异较为明显。利用差谱中特征区和指纹区的差异可快速鉴别出该八种鹅膏菌。研究表明: 傅里叶变换红外光谱技术能提供大型真菌所含化学成分的分子结构信息, 结合差谱技术可以鉴别同属下的不同种高等真菌。     

Fourier Transform Emission Spectroscopy of CuCl

The electronic spectra of CuCl were observed in the 18 000 cm(-1) to 25 000 cm(-1) spectral region using a Bruker IFS 120 HR Fourier transform spectrometer (FTS) and with the FTS associated with the McMath-Pierce Solar Telescope at Kitt Peak. On the basis of ab initio calculations, the labels for the electronic states were revised, and the a(3)Sigma(+)(1)-X(1)Sigma(+) 0-0 band, the b(3)Pi(0)-X(1)Sigma(+) 0-0, 1-0, and 0-1 bands, the b(3)Pi(1)-X(1)Sigma(+) 0-0, 1-0, and 0-1 bands, the A(1)Pi-X(1)Sigma(+) 0-0, 1-0, and 0-2 bands, and the B(1)Sigma(+)-X(1)Sigma(+) 0-0 and 1-0 bands were measured. Improved spectroscopic constants were obtained for the excited and ground states. Copyright 2001 Academic Press.     

Rapid Scan Infrared Fourier Transform Spectroscopy

The characteristic asorption, reflection, or emission of particu lar frequencies of IR radiation has been used extensively over the last two decades to identify compounds and mixtures and to investigate intermolecular and intramolecular interactions. It is probably true to say that IR spectroscopy is the most widely used instrumental technique in analytical chemistry today. This is due to a variety of reasons, including the ease of operation of many IR spectrometers, the ease in which a sample may be classified according to its chemical class from its IR spectrum, the variety of states in which a compound may be investigated, the availability of libraries of IR spectra for the unique identification of a sample, and the accuracy to which quantitative analysis may be carried out.     

Fourier Transform Infrared Emission Spectroscopy of SeH

The infrared vibration-rotation bands of SeH have been measured in the X(2)Pi ground state using a Fourier transform spectrometer. The bands were observed in a microwave discharge of a mixture of H(2) and Se in the presence of He. The rotational structure of the 1-0, 2-1, 3-2 bands of the X(2)Pi(3/2) spin component and the 1-0 band of X(2)Pi(1/2) spin component has been observed in the 1800-2600 cm(-1) region. The principal ground state molecular constants obtained are omega(e) = 2421.7153(234) cm(-1), omega(e)x(e) = 44.6012(110) cm(-1), omega(e)y(e) = 0.20697(236) cm(-1), B(e) = 7.899187(696) cm(-1), alpha(e) = 0.220749(399) cm(-1), and r(e) = 1.464319(64) ?. This work is the first determination of the equilibrium molecular constants of the X(2)Pi state of SeH. Copyright 2000 Academic Press.     

New High-Resolution Analysis of the nu(3) Band of the (15)N(16)O(2) Isotopomer of Nitrogen Dioxide by Fourier Transform Spectroscopy

New high-resolution Fourier transform absorption spectra of an (15)N(16)O(2) isotopic sample of nitrogen dioxide were recorded at the University of Bremen in the 6.3-μm region. Starting from the results of a previous study [Y. Hamada, J. Mol. Struct. 242, 367-377 (1991)], a new and more extended analysis of the nu(3) band located at 1582.1039 cm(-1) has been performed. The spin-rotation energy levels were satisfactorily reproduced using a theoretical model which takes into account both the Coriolis interactions between the spin-rotation energy levels of the (001) vibrational state with those of the (020) and (100) states and the spin-rotation resonances within each of the NO(2) vibrational states. Precise vibrational energies and rotational, spin-rotation, and coupling constants were obtained in this way for the first triad of (15)N(16)O(2) interacting states {(020), (100), (001)}. Finally, a comprehensive list of line positions and line intensities of the {nu(1), 2nu(2), nu(3)} interacting bands of (15)N(16)O(2) was generated, using for the line intensities the transition moment operators which were obtained previously for the main isotopic species. Copyright 2000 Academic Press.     

用傅里叶红外光谱法对几种西药的检测鉴别与分析

本文采用傅里叶红外光谱法分别对几种西药阿莫西林胶囊、利君沙片、吗丁啉片、康必得片样品进行了检测鉴别分析。由于西药的有效成份明确,分子结构确定,各分子基团的振动红外光谱谱峰具有明显的对应特征,故而快速检测鉴别出各组西药样品中均有假药存在,而且检测出这些假药均是由一种制药的辅料——糊精所制成。     

绿色翡翠的傅里叶红外光谱分析

对几种绿色翡翠进行了傅里叶红外光谱分析,谱图分析结果显示:3500cm-1处存在-特征峰,且随着硬玉质地和颜色的不同,其峰形也存在差异.     

引种紫锥菊不同部位的红外光谱分析与鉴定

采用红外光谱宏观指纹鉴定的方法对紫锥菊不同部位根、茎、叶、花原药材及醇溶、水溶提取物的一维和二阶导数谱图进行整体分析.原药材谱图显示紫锥菊的各部位都体现淀粉特征峰.醇提物二阶导数谱图给出花中1711 cm-1、1630 cm-1的羧基吸收峰明显强于其他部位,说明花中多酚类成分高于其他部位.水提物谱图显示,花、叶中多酚类...     

小米的傅里叶变换红外光谱研究

本文利用傅里叶变换红外光谱(FTIR)结合主成分分析和聚类分析对白小米、黄小米、糯小米、青小米、陈黄小米、黑小米和大黄米进行鉴别研究。所有样品的傅里叶变换红外光谱整体相似,二阶导数光谱存在明显的差异。选取1800~1400cm-1范围内的二阶导数光谱数据对52份小米样品做多变量分析,结果显示,主成分分析的分类准确率为84.6%,系统聚类分析的分类准确率为92.3%。结果表明傅里叶变换红外光谱技术结合化学计量学能有效地区分不同品种的小米,为不同小米的分类鉴定提供新的方法与途径。     

High-Resolution Infrared Spectra of the OOO Ozone Isotopomer in the Range 900-5000 cm: Line Positions

In pursuing the systematic study of ozone high-resolution infrared spectra, we present here the analysis of line positions of the ¹⁶O¹⁸O¹⁶O isotopomer. The recorded spectra cover the range 900-5000 cm⁻¹, that has allowed 13 bands to be observed: ν₁, ν₃, 2ν₂, ν₂+ν₃, ν₁+ν₂, ν₁+ν₃, ν₁+ν₂+ν₃, 3ν₃, 2ν₁+ν₃, ν₂+3ν₃, ν₁+3ν₃, ν₁+ν₂+3ν₃, and 5ν₃. The analysis of these bands has been performed using effective rovibrational Hamiltonians for 10 polyads of interacting upper vibrational states. To correctly reproduce all observed transitions, it has been necessary to account for resonance perturbations due to “dark” states: (002), (200), (012), (210), (102), (310), (004), (014), (320), (104), and (311). We present the results for spectroscopic parameters (vibrational energy levels, rotational and centrifugal distortion constants, and resonance coupling parameters), as well as the statistics for rovibrational energy levels, range of observed transitions, and typical example of wavefunction mixing coefficients. A comparison of observed band centers with those predicted from an isotopically invariant potential function is discussed. The R.M.S. deviation between predicted and directly observed band centers is ≈0.2 cm⁻¹ up to 2800 cm⁻¹ and ≈0.5 cm⁻¹ for all 13 bands up to 4800 cm⁻¹.     

玉米花粉中营养物质的傅里叶变换红外光谱特征

为了研究玉米花粉中的蛋白质和多糖等营养物质,采用傅里叶变换红外光谱结合曲线拟合技术分析曲辰9号和靖丰3号两种杂交玉米花粉.玉米花粉的傅里叶变换红外光谱显示蛋白质的特征吸收峰酰胺I带、酰胺II带和酰胺III带出现在1 653cm-1、1 546cm-1和1 241cm-1附近,多糖特征吸收峰出现在1 078cm-1、1 056cm-1、1 030cm-1和995cm-1附近.对比它们的傅里叶变换红外光谱的蛋白质和多糖特征吸收带,两种玉米花粉存在一定差异,表明它们所含的蛋白质和多糖含量不同.对1 900~950cm-1吸收带实施傅里叶自去卷积和二阶导数处理后再进行曲线拟合分析,剥离出因光谱叠加而掩盖的特征吸收子峰.子峰信息显示曲辰9号玉米花粉中多糖的含量高于靖丰3号玉米花粉,而蛋白质的含量关系则相反.研究表明,傅里叶变换红外光谱技术可为玉米花粉中营养物质的研究提供一种便捷的手段.     

傅里叶变换近红外反射用于鸡蛋蛋品质的研究

鸡蛋的无损检测技术一直以来都是蛋品质检测领域的重要研究课题,建立相应的检测技术对蛋鸡育种和蛋品质监测具有实际意义.文章利用近红外光谱仪测定保存时间不同的鸡蛋,探讨了蛋白高度、哈氏单位、气室直径、气室高度近红外模型的可行性,并运用无偏最小二乘法建立了鸡蛋蛋白高度、鸡蛋气室直径、气室高度的近红外测定模型,蛋白高度、气室直径与气室高度的测定模型的决定系数R2分别为0.867,0.821,0.865,RMSECV分别为0.476,0.014与0.479.对33个鸡蛋样品的模型验证的R2分别为0.873,0.861,0.895.鸡蛋新鲜度主要指标的预测值与实际值间的差异不显著(P＞0.05),所建模型具有较好的准确性与预测能力,能够满足蛋品新鲜度快速无损检测的要求.     

普洱茶的傅里叶变换红外光谱鉴别研究

利用傅里叶变换红外光谱法研究了云南省思茅地区所产不同等级的普洱生茶和熟茶。结果显示:生普和熟普的红外光谱虽然整体上十分相似,但由于生普和熟普的生产工艺不同,其化学成分的组成比例也各异,因而生普和熟普均具有其各自的特征红外光谱,且不同品质的生普和不同品质的熟普之间,其红外光谱均有明显的差异。根据红外光谱的特征峰形和吸光度比不仅可以区分生普和熟普,而且有可能区分生普或熟普的不同品质级别。傅里叶红外光谱法快速、简便、直观且样品不需要分离提取,适用于普洱茶的级别鉴别。     

应用红外光谱技术快速检测月桂酸单甘油酯的品质指标

月桂酸单甘油酯是用途广泛的食品添加剂,在其制备过程中经分子蒸馏得到的制备品中会有月桂酸、甘油等杂质。用化学滴定或气相色谱等传统方法检测制备品中的月桂酸单甘油酯纯度及其杂质含量过程相当繁琐。为了对月桂酸单甘油酯制备品的品质进行快速定量,先利用气相色谱法确定不同工艺下的月桂酸单甘油酯产品中各成分的含量,再利用傅立叶红外光谱仪对月桂酸单甘油酯制备品进行分析,得到它们的光谱数据曲线,并结合主成分分析和反向传播神经网络建立回归模型。通过对实验结果的均方根误差预测值PRMSE以及相关系数r辨析,预测月桂酸单甘油酯含量的结果为PRMSE=3.6376,r=0.9950,预测甘油含量的结果为PRMSE=1.4764,r=0.9795,预测月桂酸含量的结果为PRMSE=1.2859,r=0.9247。结果表明,应用光谱分析方法能够较好检测月桂酸单甘油酯、月桂酸和甘油含量。