一种实现光声光谱的导数光谱的新方法

提出了一种实现光声光谱的导数光谱的新方法,为了获得光声光谱的导数光谱,利用一台单色仪和一个分光棱镜研制成一个波长-光强分束器,并用这个波长-光强分束器同时获得两束光强相等而波长有微小差别的两束光,这两束光经过一个互补调制器调制后在光声探测器内叠加,可以实现光声信号的差分,扫描单色仪的波长,就可以获得光声吸收光谱的导数光谱。实验证明这种方法可以准确实现光声光谱的一阶导数光谱,而且导数光声光谱比光声吸收光谱具有更高的光谱分辨率。     

Simple and sensitive spectrophotometric methods for determination of amantadine hydrochloride

Three simple and sensitive spectrophotometric methods (A–C) for determination of amantadine hydro-chloride have been developed and validated. The first method (A) is based on the oxidation of the drug by ammonium molybdate. The second method (B) was based on the charge-transfer complexation reaction between the amantadine base as an electron donor and iodine as a σ-acceptor. The third method (C) is based on the reaction of N-alkylvinylamine formed from the interaction of the free amino group in amantadine molecule and acetalde-hyde with chloranil to give colored vinylamino-substituted benzoquinone. The colored products of these reactions were measured at their corresponding maximum absorption peaks. Different variables affecting the reactions were carefully studied and optimized. Under the optimum conditions, linear relationships with good correlation coefficients 0.9993–0.9998 were found between the reading and the corresponding concentration of the drug in the range 2–90 μg·ml⁻¹. The limits of detection ranged from 0.16 to 1.91 μg·ml⁻¹. The precision of the methods was satisfactory: the values of relative standard deviation did not exceed 1.63%. The proposed methods were successfully applied to the analysis of amantadine HCl in its capsules with good accuracy and precision; the label claim percentages ranged from 99.8 to 100.5 ± (0.52–1.22) %. The results obtained by the proposed spectrophotometric methods were comparable with those obtained by the official method. Published in Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 6, pp. 707–712.     

Thermoluminescence excitation spectroscopy: A versatile technique to study persistent luminescence phosphors

A versatile new facility to study photoionization processes in impurity doped compounds is presented. In this new facility monochromatic light is coupled to a thermoluminescence reader, enabling a fully automated recording of glow curves as a function of photon excitation wavelength. It provides detailed information on the mechanism of trap filling preceding persistent luminescence. The technique is first demonstrated with a study on Lu₂SiO₅:Ce³⁺ and then applied to commercial modern day double lanthanide doped SrAl₂O₄:Eu²⁺,Dy³⁺, Sr₄Al₁₄O₂₅:Eu²⁺,Dy³⁺, CaAl₂O₄:Eu²⁺,Nd³⁺; and to the classical ZnS:Cu⁺ persistent luminescence phosphors. The presented data provide new insight into the mechanism of persistent luminescence.     

Absorption and Luminescence Spectra of Tetra (3-Pyridyl)Porphyrazine: A Convergent Spectroscopic Method for the Elucidation of Association Reactions in Solution

Tetra(3-pyridyl)porphyrazine is soluble in trifluoroethanol yielding intense blue solutions. The electronic spectra exhibit the characteristic Soret and Q bands around 330 and 610 nm, respectively; however, the absorption profile is strongly dependent on the concentration, reflecting the occurrence of an association process. The system has been elucidated by solving the equilibrium and the absorbance-concentration equations for all the wavelengths in the spectral range, according to a variational procedure. In this way the consistent spectra of the individual species have been generated. The study has also been extended to the luminescence properties of the porphyrazine molecule, and discussed in terms of the ground state association and the exciplex formation involving the monomeric species.     

A Vibrational Spectroscopic Study of the Sulfate Mineral Glauberite

The mineral glauberite is one of many minerals formed in evaporite deposits. The mineral glauberite has been studied using a combination of scanning electron microscopy with energy dispersive X-ray analysis and infrared and Raman spectroscopy. Qualitative chemical analysis shows a homogeneous phase, composed by sulfur, calcium, and sodium. Glauberite is characterized by a very intense Raman band at 1002 cm^?1 with Raman bands observed at 1107, 1141, 1156, and 1169 cm^?1 attributed to the sulfate ν₃ antisymmetric stretching vibration. Raman bands at 619, 636, 645, and 651 cm^?1 are assigned to the ν₄ sulfate bending modes. Raman bands at 454, 472, and 486 cm^?1 are ascribed to the ν₂ sulfate bending modes. The observation of multiple bands is attributed to the loss of symmetry of the sulfate anion. Raman spectroscopy is superior to infrared spectroscopy for the determination of glauberite.     

Spectroscopic determination of binding between human serum albumin and a platinum(II) dimethylsulfoxide complex

We have used electronic absorption and fluorescence spectroscopy to study binding between a platinum(II) dimethylsulfoxide complex (cis-[Pt(DMSO)₂Cl₂]) and human serum albumin (HSA), and the effect of complexation on the structure of the protein. We have calculated the binding parameters for binding between cis-[Pt(DMSO)₂Cl₂] and HSA. We have determined the binding constant K_B = (1.2 ± 0.1)·10³ M⁻¹ and the Hill coefficient h = 1.03 ± 0.1. We have determined that binding between cis-[Pt(DMSO)₂Cl₂] and the protein leads to a change in the internal packing of the macromolecule. __________ Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 75, No. 4, pp. 573–576, July–August, 2008.     

Vibrational Spectroscopic Characterization of the Sulphate-Carbonate Mineral Burkeite: Implications for Evaporites

Burkeite formation is important in saline evaporites and in pipe scales. Burkeite is an anhydrous sulphate-carbonate with an apparent variable anion ratio. Such a formula with two oxyanions lends itself to vibrational spectroscopy. Two symmetric sulphate stretching modes are observed, indicating at least at the molecular level the nonequivalence of the sulphate ions in the burkeite structure. The strong Raman band at 1065 cm^?1 is assigned to the carbonate symmetric stretching vibration. The series of Raman bands at 622, 635, 645, and 704 cm^?1 are assigned to the ν₄ sulphate bending modes. The observation of multiple bands supports the concept of a reduction in symmetry of the sulphate anion from T _d to C _3v or even C _2v.     

Reality-inspired voter models: A mini-review

This mini-review presents extensions of the voter model that incorporate various plausible features of real decision-making processes by individuals. Although these generalizations are not calibrated by empirical data, the resulting dynamics are suggestive of realistic collective social behaviors.     

Spectroscopic techniques for the forensic analysis of textile fibers

A review has been conducted on the application of the spectroscopic techniques to the comparative study and identification of different textile fibers. Microspectrophotometry in the ultraviolet-visible range and Raman spectroscopy are the main techniques investigated with this aim in the forensic field. UV-Vis MSP is the first recommended technique, which is principally used to study the color of the fibers. A more complete approximation focused on determining the specific color of the fibers providing adding Raman spectroscopy to the analytical scheme. Sometimes, it also provided information about the polymeric nature of the fibers. Regarding FTIR spectroscopy, it is the recommended tool to determine the fiber nature. Raman and FTIR spectroscopy are complementary techniques and a frequent recommendation is a combination of both techniques, in order to get a comprehensive analysis of textile fibers. On the other hand, new and more informative analytical techniques are emerging to the analysis of textile fibers as traces related with criminal contacts, such as infrared chemical imaging spectroscopy and X-ray fluorescence spectroscopy.     

Spectroscopic Trends for the Determination of Illicit Drugs in Oral Fluid

Abstract

The present work aims to review all of the articles published so far, focused on the determination of drugs of abuse in oral fluid. This fluid provides a simpler, faster, and more controllable sampling in comparison with the other biological fluids, such as blood or urine. Actually, the main goal of the researchers is to lower the limit of detection (LOD) to detect quantities of drugs smaller than the cut-off limits established by law for drug controls. Advances in Raman, infrared (IR), and nuclear magnetic resonance (NMR) spectroscopy applications are discussed. Surface-enhanced Raman spectroscopy (SERS) has been shown as the most sensitive technique for the detection of illicit drugs in oral fluid. The use of IR spectroscopy for determining drugs of abuse in oral fluid is growing, although the LODs obtained until now do not yet satisfy the necessities in the forensic field. Finally, NMR spectroscopy has seldom been used to determine drugs in oral fluid. Another future trend seems to be related with the use of portable instrumentation, which would allow us to perform in-situ analysis. This last application seems to be particularly promising to perform roadside drug tests and to identify overdose drugs in patients in emergency conditions.     

改进偏最小二乘法在近红外牛奶成分测量中的应用

采用NicoletNexus870红外-近红外傅里叶变换光谱仪测量了36个市售巴氏杀菌纯牛乳样品的透射光谱。在近红外光谱1254～1875nm和2045～2372nm波段内,为了选择携带信息量大的波长区域,采用改进偏最小二乘回归法,包括间隔偏最小二乘法、移动窗口偏最小二乘法和可变窗宽移动窗口偏最小二乘法对巴氏杀菌纯牛乳中脂肪、蛋白质及乳糖成分分别建立模型,进行了分析和比较,结果表明,采用改进偏最小二乘法所选出的波长区与目标值的相关程度高,可以较好地建立牛奶的预测模型。     

From the infrared to the visible range: Spectroscopic studies of ytterbium doped oxyborates

The spectroscopic study of yttrium oxyborates doped with trivalent ytterbium is conducted in the UV-Visible and infrared range. The multiplicity of the ytterbium environments in the studied compounds leads to complex emission spectra in the infrared and excitation spectra in the ultraviolet. Different ²F_5/2 and ²F_7/2 transitions have been pointed out. The emission extends up to 1090 nm for one compound. A correlation was evidenced between position and de-excitation mode of a charge transfer band and ytterbium environment for both oxyborates. Decay time dependence as a function of ytterbium concentration is also reported. For the highest concentration, a blue-green luminescence can be observed under strong IR excitation. Its study revealed two possible mechanisms: erbium ion emission at 550 nm after up-conversion and cooperative luminescence of ytterbium ions.     

Spectroscopic techniques as potential screening tools for preterm birth: A review and an exploratory study

Preterm birth (PTB) is the single-most important determinant of infant adverse outcome worldwide, accounting for over 1 million neonatal deaths a year. Given its complex pathophysiology, prediction and prevention of PTB remain elusive. Current screening methods lack accuracy and reliability, and have failed to reduce the incidence and consequences of PTB. Hence, there remains a real need to develop noninvasive and more cost-effective screening tests, which can facilitate earlier identification of women at greatest risk, more timely prevention, and better risk stratification and management of PTB. Spectroscopic techniques have shown great promise to meet this demand. Therefore, in this article, the literature is reviewed to assess current evidence regarding the potential application of spectroscopic techniques to predict PTB via in vitro analysis of biofluids as well as in vivo study of cervical remodeling. In addition, preliminary data exploring the use of Raman spectroscopy (RS) to analyze cervicovaginal fluid (CVF) in pregnancy as a predictive tool for PTB is detailed for the first time with the aim to inform future avenues of research.     

Kinetics of fluorescence polarization for solid bichromophore solutions in intense pulse excitation

The kinetics of fluorescence polarization in intense pulse excitation of solid disordered solutions of bichromophores that consist of complex molecules of two types between which there can be inductiveresonance transfer of electron-excitation energy is theoretically investigated. Variants of fluorescence excitation by single pulses and pulse trains are considered. The lifetime of the fluorescence of a given solution increases with the intensity of the exciting pulses. The possibility of controlling the duration of fluorescence attenuation for donor molecules incorporated into the bichromophores by the action of luminescence radiation at the frequency of acceptor-molecule absorption on the solution is demonstrated. Belarusian State University, 4, F. Skorina Ave., Minsk, 220050, Belarus. Translated from Zhurnal Prikladnoi Spektroskopii Vol. 65, No. 4, pp. 546–550, July–August, 1998.     

Determination of Total Petroleum Hydrocarbon (TPH) and Polycyclic Aromatic Hydrocarbon (PAH) in Soils: A Review of Spectroscopic and Nonspectroscopic Techniques

Abstract: In the analysis of petroleum hydrocarbon–contaminated soils for total petroleum hydrocarbons (TPHs) and polycyclic aromatic hydrocarbons (PAHs), the roles of spectroscopic and nonspectroscopic techniques are inseparable. Therefore, spectroscopic techniques cannot be discussed in isolation. In this report, spectroscopic techniques including Raman, fluorescence, infrared, and visible and near-infrared (Vis-NIR) spectroscopies, as well as mass spectroscopy (coupled to a gas chromatograph) and nonspectroscopic techniques such as gravimetry, immunoassay, and gas chromatography with flame ionization detection are reviewed. To bridge the perceived gap in coverage of the quantitative applications of Vis-NIR spectroscopy in the rapid determination of TPHs and PAHs in soils, a detailed review of studies from the period 1999–2012 are presented. This report also highlights the strengths and limitations of these techniques and evaluates their performance from the perspective of their attributes of general applicability, namely economic portability, operational time, accuracy, and occupational health and safety considerations. Overall, the fluorescence spectroscopic technique had the best performance (85% total score) in comparison to the others, and the gravimetric technique performed the least (60% total score). Method-specific solutions geared toward performance improvement are also suggested.     

A RAMAN Spectroscopic Investigation of Alloxan and Alloxan Monohydrate

Abstract

The present Raman investigation of anhydrous alloxan and the misnamed alloxan monohydrate suggests that some of the assignments previously made on basis of the IR spectrum of the anhydrous compound must be changed, i.e., the ones related to the NH stretching and ring breathing modes. The hydrogen bonding network in the crystal of the so called alloxan monohydrate, although extensive, is not strong enough to cause substantial frequency shifts in the NH and CO stretching modes.     

嘧螨酯波谱学数据全归属

嘧螨酯为一种新型杀螨剂和STAT₃激活抑制剂. 该文对嘧螨酯的紫外吸收光谱(UV)、红外吸收光谱(IR)、质谱(MS)、核磁共振氢谱(¹H NMR)、核磁共振碳谱(¹³C NMR)、DEPT谱、¹H-¹H COSY谱、异核单量子相关谱(HSQC)、异核多键相关谱(HMBC)进行了解析,并对该化合物所有的核磁信号进行了全归属;同时讨论了紫外光谱吸收带位置和吸收强度与该化合物的生色团对应关系、红外光谱特征吸收峰与该化合物的各官能团的对应关系、氟原子(F)对其¹³C NMR的影响以及质谱离子碎片的归属和化合物的裂解规律. 该研究将为嘧螨酯的结构确证及其他相关研究提供参考.     

粗糙银电极上高铁血红素的非共振表面增强拉曼光谱研究

以632.8nm为激发线,研究了高铁血红素的非共振表面增强拉曼光谱。结果表明,高铁血红素的氧化和还原状态的拉曼谱图以B_(1g)振动模式为主;血红素以丙酸侧基直接吸附于电极表面,叶啉环则以垂直于电极表面的形式存在。B_(1g)振动模式v_(15)对血红素中心铁的氧化还原状态十分敏感,被指认为非共振条件下血红素氧化还原状态的特征谱峰。     

A Review of the Vibrational Spectroscopic Studies of Arsenite,Antimonite, and Antimonate Minerals

Abstract

This review focuses on the vibrational spectroscopy of the compounds and minerals containing the arsenite, antimonite, and antimonate anions. The review collects and correlates the published data.