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Sample records for ft-ir ft-ir gas

  1. Quantitative gas analysis with FT-IR

    DEFF Research Database (Denmark)

    Bak, J.; Larsen, A.

    1995-01-01

    Calibration spectra of CO in the 2.38-5100 ppm concentration range (22 spectra) have been measured with a spectral resolution of 4 cm(-1), in the mid-IR (2186-2001 cm(-1)) region, with a Fourier transform infrared (FT-IR) instrument. The multivariate calibration method partial least-squares (PLS1...

  2. EVOLVED GAS ANALYSIS (COUPLED TG-DSC-FT-IR APPLIED IN THE STUDY OF FRUCTOOLIGOSACCHARIDES FROM CHICORY

    Directory of Open Access Journals (Sweden)

    Roberta de Souza Leone

    2014-08-01

    Full Text Available EGA (Evolved Gas Analysis is a group of coupled techniques (in this case TG-DSC and FT-IR that was used to provide information about the thermal and calorimetric behavior of standard fructooligosaccharides (FOS from chicory. These FOS are found in several foods (tuber, roots, fruits, leaves, cereals, etc. and have been the subject of several studies. In the present study thermogravimetry (TG allowed the characterization of FOS a standard (Sigma-Aldrich, in which the weight loss can be observed in three stages (m 7.56, 55.53 and 36.53%, respectively. The simultaneous use of DSC showed endo and exothermic events in temperature characteristics and in agreement with TG curves. The enthalpies of the main stages of decomposition were calculated: ΔHdehydr 260 J g-1 and ΔHdec 410 J g-1. From the FT-IR spectrum of the volatiles was possible to characterize the main bands, which confirmed CO and CO2 as a result of thermal decomposition.

  3. On-Chip Micro-Electro-Mechanical System Fourier Transform Infrared (MEMS FT-IR) Spectrometer-Based Gas Sensing.

    Science.gov (United States)

    Erfan, Mazen; Sabry, Yasser M; Sakr, Mohammad; Mortada, Bassem; Medhat, Mostafa; Khalil, Diaa

    2016-05-01

    In this work, we study the detection of acetylene (C2H2), carbon dioxide (CO2) and water vapor (H2O) gases in the near-infrared (NIR) range using an on-chip silicon micro-electro-mechanical system (MEMS) Fourier transform infrared (FT-IR) spectrometer in the wavelength range 1300-2500 nm (4000-7692 cm(-1)). The spectrometer core engine is a scanning Michelson interferometer micro-fabricated using a deep-etching technology producing self-aligned components. The light is free-space propagating in-plane with respect to the silicon chip substrate. The moving mirror of the interferometer is driven by a relatively large stroke electrostatic comb-drive actuator corresponding to about 30 cm(-1) resolution. Multi-mode optical fibers are used to connect light between the wideband light source, the interferometer, the 10 cm gas cell, and the optical detector. A wide dynamic range of gas concentration down to 2000 parts per million (ppm) in only 10 cm length gas cell is demonstrated. Extending the wavelength range to the mid-infrared (MIR) range up to 4200 nm (2380 cm(-1)) is also experimentally demonstrated, for the first time, using a bulk micro-machined on-chip MEMS FT-IR spectrometer. The obtained results open the door for an on-chip optical gas sensor for many applications including environmental sensing and industrial process control in the NIR/MIR spectral ranges.

  4. Kinetics and evolved gas analysis for pyrolysis of food processing wastes using TGA/MS/FT-IR.

    Science.gov (United States)

    Özsin, Gamzenur; Pütün, Ayşe Eren

    2017-06-01

    The objective of this study was to identify the pyrolysis of different bio-waste produced by food processing industry in a comprehensible manner. For this purpose, pyrolysis behaviors of chestnut shells (CNS), cherry stones (CS) and grape seeds (GS) were investigated by thermogravimetric analysis (TGA) combined with a Fourier-transform infrared (FT-IR) spectrometer and a mass spectrometer (MS). In order to make available theoretical groundwork for biomass pyrolysis, activation energies were calculated with the help of four different model-free kinetic methods. The results are attributed to the complex reaction schemes which imply parallel, competitive and complex reactions during pyrolysis. During pyrolysis, the evolution of volatiles was also characterized by FT-IR and MS. The main evolved gases were determined as H2O, CO2 and hydrocarbons such as CH4 and temperature dependent profiles of the species were obtained. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Orchids and Bee's Knees: Investigating the Euglossine Syndrome with Gas Chromatography/Fourier Transform Infrared GC/FT-IR

    Science.gov (United States)

    McClure, Gregory L.; Williams, N. H...; Whitten, W. M.

    1985-12-01

    The GC/FT-IR analysis of a fragrance obtained from a Gongora tricolor orchid is described. The significance of this type of analysis is explained in terms of the elucidation of the complex relationship between orchids and bees known as "The Euglossine Syndrome". The fragrance sample was found to contain p-cresol, p-methylanisole and a variety of terpenoids, including myrcene, cineole, limonene, cymene, ipsdienol, and an olefinic product which appears to be the dehydration product of ipsdienol.

  6. Comparison of Genetic Parameters Estimation of Fatty Acids from Gas Chromatography and FT-IR in Holsteins

    DEFF Research Database (Denmark)

    Poulsen, Nina Aagaard; Eskildsen, C E A; Skov, Thomas;

    Fourier transform infrared (FT-IR) is routinely used in the milk recording system and IR-based solutions are therefore attractive to ensure the full potential of genomic selection data in future breeding programs. Today, IR-based models can be used to predict a wide range of milk traits......, and their genetic parameters. However, IR-predicted phenotypes for detailed milk composition are often based on their correlation to other traits in a given data set rather than on direct predictions. Here, genetic parameters for individual milk fatty acids were estimated based on either IR-predicted phenotypes...

  7. Characterization of Momordica charantia Ussing FT-IR Spectroscopy

    Directory of Open Access Journals (Sweden)

    Attila Keseru

    2016-11-01

    In this paper, because earlier claim shows that the plant used as stomachic, carminative, tonic, antipyretic, antidiabetic, in rheumatoid arthritis and gout, the present investigation was carried to characterized a principal components of plant using FT-IR technique

  8. Vibrational microspectroscopy of food. Raman vs. FT-IR

    DEFF Research Database (Denmark)

    Thygesen, Lisbeth Garbrecht; Løkke, Mette Marie; Micklander, Elisabeth

    2003-01-01

    FT-IR and Raman spectroscopy are complementary techniques for the study of molecular vibrations and structure. The combination with a microscope results in an analytical method that allows spatially resolved investigation of the chemical composition of heterogeneous foods and food ingredients....... The high spatial resolution makes it possible to study areas down to approximately 10x10 mum with FT-IR microspectroscopy and approximately 1 x 1 mum with Raman microspectroscopy. This presentation highlights the advantages and disadvantages of the two microspectroscopic techniques when applied...... to different heterogeneous food systems. FT-IR and Raman microspectroscopy were applied to a number of different problems related to food analysis: (1) in situ determination of starch and pectin in the potato cell, (2) in situ determination of the distribution of amygdalin in bitter almonds, (3...

  9. Raman and FT-IR studies of ocular tissues

    Science.gov (United States)

    Ozaki, Yukihiro; Mizuno, Aritake

    1991-05-01

    Two examples of Raman and FT-IR studies of the ocular tissues are reviewed in this paper. The first example treats Raman studies on cataract development cataract-related lens hydration and structural changes in the lens proteins monitored in situ by Raman spectroscopy are described. The second example is concerned with FT-IR studies on the ocular tissues contain ing collagen nondestructive identification of Type I and IV collagen in the tissues and their structural differences elucidated by infrared spectroscopy are discussed. 1 .

  10. On the Use of Fourier Transform Infrared (FT-IR) Spectroscopy and Synthetic Calibration Spectra to Quantify Gas Concentrations in a Fischer-Tropsch Catalyst System

    Science.gov (United States)

    Ferguson, Frank T.; Johnson, Natasha M.; Nuth, Joseph A., III

    2015-01-01

    One possible origin of prebiotic organic material is that these compounds were formed via Fischer-Tropsch-type (FTT) reactions of carbon monoxide and hydrogen on silicate and oxide grains in the warm, inner-solar nebula. To investigate this possibility, an experimental system has been built in which the catalytic efficiency of different grain-analog materials can be tested. During such runs, the gas phase above these grain analogs is sampled using Fourier transform infrared (FT-IR) spectroscopy. To provide quantitative estimates of the concentration of these gases, a technique in which high-resolution spectra of the gases are calculated using the high-resolution transmission molecular absorption (HITRAN) database is used. Next, these spectra are processed via a method that mimics the processes giving rise to the instrumental line shape of the FT-IR spectrometer, including apodization, self-apodization, and broadening due to the finite resolution. The result is a very close match between the measured and computed spectra. This technique was tested using four major gases found in the FTT reactions: carbon monoxide, methane, carbon dioxide, and water. For the ranges typical of the FTT reactions, the carbon monoxide results were found to be accurate to within 5% and the remaining gases accurate to within 10%. These spectra can then be used to generate synthetic calibration data, allowing the rapid computation of the gas concentrations in the FTT experiments.

  11. FT-IR Microspectroscopy of Rat Ear Cartilage.

    Directory of Open Access Journals (Sweden)

    Benedicto de Campos Vidal

    Full Text Available Rat ear cartilage was studied using Fourier transform-infrared (FT-IR microspectroscopy to expand the current knowledge which has been established for relatively more complex cartilage types. Comparison of the FT-IR spectra of the ear cartilage extracellular matrix (ECM with published data on articular cartilage, collagen II and 4-chondroitin-sulfate standards, as well as of collagen type I-containing dermal collagen bundles (CBs with collagen type II, was performed. Ear cartilage ECM glycosaminoglycans (GAGs were revealed histochemically and as a reduction in ECM FT-IR spectral band heights (1140-820 cm-1 after testicular hyaluronidase digestion. Although ear cartilage is less complex than articular cartilage, it contains ECM components with a macromolecular orientation as revealed using polarization microscopy. Collagen type II and GAGs, which play a structural role in the stereo-arrangement of the ear cartilage, contribute to its FT-IR spectrum. Similar to articular cartilage, ear cartilage showed that proteoglycans add a contribution to the collagen amide I spectral region, a finding that does not recommend this region for collagen type II quantification purposes. In contrast to articular cartilage, the symmetric stretching vibration of -SO3- groups at 1064 cm-1 appeared under-represented in the FT-IR spectral profile of ear cartilage. Because the band corresponding to the asymmetric stretching vibration of -SO3- groups (1236-1225 cm-1 overlapped with that of amide III bands, it is not recommended for evaluation of the -SO3- contribution to the FT-IR spectrum of the ear cartilage ECM. Instead, a peak (or shoulder at 1027-1016 cm-1 could be better considered for this intent. Amide I/amide II ratios as calculated here and data from the literature suggest that protein complexes of the ear cartilage ECM are arranged with a lower helical conformation compared to pure collagen II. The present results could motivate further studies on this tissue

  12. FT-IR Microspectroscopy of Rat Ear Cartilage.

    Science.gov (United States)

    Vidal, Benedicto de Campos; Mello, Maria Luiza S

    2016-01-01

    Rat ear cartilage was studied using Fourier transform-infrared (FT-IR) microspectroscopy to expand the current knowledge which has been established for relatively more complex cartilage types. Comparison of the FT-IR spectra of the ear cartilage extracellular matrix (ECM) with published data on articular cartilage, collagen II and 4-chondroitin-sulfate standards, as well as of collagen type I-containing dermal collagen bundles (CBs) with collagen type II, was performed. Ear cartilage ECM glycosaminoglycans (GAGs) were revealed histochemically and as a reduction in ECM FT-IR spectral band heights (1140-820 cm-1) after testicular hyaluronidase digestion. Although ear cartilage is less complex than articular cartilage, it contains ECM components with a macromolecular orientation as revealed using polarization microscopy. Collagen type II and GAGs, which play a structural role in the stereo-arrangement of the ear cartilage, contribute to its FT-IR spectrum. Similar to articular cartilage, ear cartilage showed that proteoglycans add a contribution to the collagen amide I spectral region, a finding that does not recommend this region for collagen type II quantification purposes. In contrast to articular cartilage, the symmetric stretching vibration of -SO3- groups at 1064 cm-1 appeared under-represented in the FT-IR spectral profile of ear cartilage. Because the band corresponding to the asymmetric stretching vibration of -SO3- groups (1236-1225 cm-1) overlapped with that of amide III bands, it is not recommended for evaluation of the -SO3- contribution to the FT-IR spectrum of the ear cartilage ECM. Instead, a peak (or shoulder) at 1027-1016 cm-1 could be better considered for this intent. Amide I/amide II ratios as calculated here and data from the literature suggest that protein complexes of the ear cartilage ECM are arranged with a lower helical conformation compared to pure collagen II. The present results could motivate further studies on this tissue under

  13. Applications of FT-IR spectrophotometry in cancer diagnostics.

    Science.gov (United States)

    Bunaciu, Andrei A; Hoang, Vu Dang; Aboul-Enein, Hassan Y

    2015-01-01

    This review provides a brief background to the application of infrared spectroscopy, including Fourier transform-infrared spectroscopy, in biological fluids. It is not meant to be complete or exhaustive but to provide the reader with sufficient background for selected applications in cancer diagnostics. Fourier transform-infrared spectroscopy (FT-IR) is a fast and nondestructive analytical method. The infrared spectrum of a mixture serves as the basis to quantitate its constituents, and a number of common clinical chemistry tests have proven to be feasible using this approach. This review focuses on biomedical FT-IR applications, published in the period 2009-2013, used for early detection of cancer through qualitative and quantitative analysis.

  14. Results obtained by investigating saffron ussing FT-IR spectroscopy

    Directory of Open Access Journals (Sweden)

    Luisa Andronie

    2016-11-01

    Full Text Available The biological activity and the pharmaceutical properties of plants are strongly dependent on their structure. The FT-IR spectra of saffron (commercial have been obtained. The vibrational fundamentals from the IR spectrum, were analyzed  and assigned acoording to the available literature. In the present research work the genus saffron is selected because it is famous in wold as foods and also as medicine.

  15. Fourier Transform Infrared Spectroscopy: Part II. Advantages of FT-IR.

    Science.gov (United States)

    Perkins, W. D.

    1987-01-01

    This is Part II in a series on Fourier transform infrared spectroscopy (FT-IR). Described are various advantages of FT-IR spectroscopy including energy advantages, wavenumber accuracy, constant resolution, polarization effects, and stepping at grating changes. (RH)

  16. An attenuated total reflection Fourier transform infrared (ATR FT-IR) spectroscopic study of gas adsorption on colloidal stearate-capped ZnO catalyst substrate.

    Science.gov (United States)

    Silverwood, Ian P; Keyworth, Colin W; Brown, Neil J; Shaffer, Milo S P; Williams, Charlotte K; Hellgardt, Klaus; Kelsall, Geoff H; Kazarian, Sergei G

    2014-01-01

    Attenuated total reflection Fourier transform infrared (ATR FT-IR) spectroscopy has been applied in situ to study gas adsorption on a colloidal stearate-capped zinc oxide (ZnO) surface. Infrared spectra of a colloidal stearate-capped ZnO catalyst substrate were assigned at room temperature using zinc stearate as a reference compound. Heating was shown to create a monodentate species that allowed conformational change to occur, leading to altered binding geometry of the stearate ligands upon cooling. CO2 and H2 adsorption measurements demonstrated that the ligand shell was permeable and did not cover the entire surface, allowing adsorption and reaction with at least some portion of the ZnO surface. It has been demonstrated that stearate ligands did not prevent the usual chemisorption processes involved in catalytic reactions on a model ZnO catalyst system, yet the ligand-support system is dynamic under representative reaction conditions.

  17. Differentiation of Leishmania species by FT-IR spectroscopy

    Science.gov (United States)

    Aguiar, Josafá C.; Mittmann, Josane; Ferreira, Isabelle; Ferreira-Strixino, Juliana; Raniero, Leandro

    2015-05-01

    Leishmaniasis is a parasitic infectious disease caused by protozoa that belong to the genus Leishmania. It is transmitted by the bite of an infected female Sand fly. The disease is endemic in 88 countries Desjeux (2001) [1] (16 developed countries and 72 developing countries) on four continents. In Brazil, epidemiological data show the disease is present in all Brazilian regions, with the highest incidences in the North and Northeast. There are several methods used to diagnose leishmaniasis, but these procedures have many limitations, are time consuming, have low sensitivity, and are expensive. In this context, Fourier Transform Infrared Spectroscopy (FT-IR) analysis has the potential to provide rapid results and may be adapted for a clinical test with high sensitivity and specificity. In this work, FT-IR was used as a tool to investigate the promastigotes of Leishmaniaamazonensis, Leishmaniachagasi, and Leishmaniamajor species. The spectra were analyzed by cluster analysis and deconvolution procedure base on spectra second derivatives. Results: cluster analysis found four specific regions that are able to identify the Leishmania species. The dendrogram representation clearly indicates the heterogeneity among Leishmania species. The band deconvolution done by the curve fitting in these regions quantitatively differentiated the polysaccharides, amide III, phospholipids, proteins, and nucleic acids. L. chagasi and L. major showed a greater biochemistry similarity and have three bands that were not registered in L. amazonensis. The L. amazonensis presented three specific bands that were not recorded in the other two species. It is evident that the FT-IR method is an indispensable tool to discriminate these parasites. The high sensitivity and specificity of this technique opens up the possibilities for further studies about characterization of other microorganisms.

  18. IDENTIFICATION OF BIS(2-CHLOROETHYL) ETHER HYDROLYSIS PRODUCTS BY DIRECT AQUEOUS INJECTION GC/FT-IR

    Science.gov (United States)

    Gas chromatography coupled to Fourier-transform infrared spectroscopy (GC/FT-IR) is rapidly becoming an accepted analytical technique complementary to GC/mass spectroscopy for identifying organic compounds in mixtures at low to moderate concentrations. irect aqueous injection (DA...

  19. FT-IR product studies on the OH radical and O3 initiated oxidation in gas-phase of the (methyl)-1,2-dihydroxybenzene

    Science.gov (United States)

    Bejan, I.; Olariu, R.; Barnes, I.; Mocanu, R.

    2003-04-01

    In the atmosphere, phenols are produced in the reactions of OH with BTX (benzene, toluene, xylene isomers) in substantial yields, benzene producing phenol, toluene a mixture of o-, m- and p-cresols and the xylene isomers a series of hydroxydimethylbenzenes. Recent product studies in Wuppertal have shown that the major products in the OH-radical initiated oxidation of phenols are benzenediols (1,2-dihydroxybenzenes). Apart from rate constants for the reactions of OH radicals, NO_3 radicals and O_3 with these compounds, nothing is presently known about the atmospheric chemistry of 1,2-benzenediols. In a systematic study of the gas phase atmospheric chemistry of these dihydroxy compounds, we present here preliminary results from studies on their products with OH radicals. The studies at Wuppertal on the reaction of the benzenediols with OH in a large volum photoreactor using the FT-IR technique indicate the formation of maleic anhydride (2,4-furandione) with a yield between 5-10% and an unknown ketene product in the reaction system. Preliminary studies on the products formed from the reaction of O_3 with 1,2-dihydroxybenzenes will also be presented.

  20. Semi-quantitative analysis of FT-IR spectra of humic fractions of nine US soils

    Science.gov (United States)

    Fourier Transform Infrared Spectroscopy (FT-IR) is a simple and fast tool for characterizing soil organic matter. However, most FT-IR spectra are only analyzed qualitatively. In this work, we prepared mobile humic acid (MHA) and recalcitrant calcium humate (CaHA) from nine soils collected from six ...

  1. Miniaturized FT-IR spectrometer for industrial process measurements

    Science.gov (United States)

    Herrala, Esko; Niemela, Pentti; Hannula, Tapio

    1990-08-01

    There have been made some attempts to transfer the advantages of FT-JR to industrial use. Commercially available research grade instruments have been large and rather expensive. However in many potential applications only medium resolution is required which means that the mirror displacement in a Michelson type interferometer remains short and computation of the Fourier transform can be executed by a small computer. Medium resolution gives also other advantages in spectrometer design simple source and detector optics less severe requirements for mirror transport and small size. We have used a Michelson type interferometer where the moving mirror is suspended by two flexures and driven by a coil actuator. Displacement of the mirror is monitored using moire transducer which is much smaller and has better thermal stability than the conventionally used HeNe laser. The beamsplitter is a standard CaF2/Si and a thermoelectrically cooled PbSe is used as the detector. In the present prototype data is transferred via parallel bus to a PC/AT compatible computer where the necessary mathematics is done. The spectral range is from 5000 to 1800 cm1 with resolution better than 8 cm1. Interferograins can be recorded several times per second and the computation time for a 2000 point spectrum is 10 seconds. Results of environmental tests carried out for the spectrometer will be presented. The results show that it is possible to construct a simple rugged and inexpensive FT-IR spectrometer

  2. Characterization of the curing agents used in epoxy resins with TG/FT-IR technique

    Directory of Open Access Journals (Sweden)

    Benedita M. V. Romão

    2006-06-01

    Full Text Available Samples of epoxy resin (EP based on the diglycidyl ether of bisphenol A (DGEBA, cured with nadic methyl anhydride (NMA and mercaptan (CAPCURE 3-800, or amine-phenol (CAPCURE EH-30, respectively, SE 4 and SE 5, were prepared in the stoichiometric ratio determined by the supplier. The curing behaviour of the epoxy systems SE 4 and SE 5 was followed by DSC (Differential Scanning Calorimetry. These SE and their ingredients were analyzed using FTIR transmission techniques (KBr pellets, pyrolysis without control and controlled pyrolysis-FT-IR, the CONTROLPIR/FT-IR for characterizing the curing agents (CA. The temperature range used for samples pyrolysis was found from TG (thermogravimetry. Thus, the FT-IR bands of liquid pyrolysate obtained by CONTROLPIR/FT-IR were evaluated, in comparison to the reference spectrum of CA. The characterization of CA was also possible, by the analysis of such SE with the TG/FT-IR technique.

  3. Final technical report. In-situ FT-IR monitoring of a black liquor recovery boiler

    Energy Technology Data Exchange (ETDEWEB)

    James Markham; Joseph Cosgrove; David Marran; Jorge Neira; Chad Nelson; Peter Solomon

    1999-05-31

    This project developed and tested advanced Fourier transform infrared (FT-IR) instruments for process monitoring of black liquor recovery boilers. The state-of-the-art FT-IR instruments successfully operated in the harsh environment of a black liquor recovery boiler and provided a wealth of real-time process information. Concentrations of multiple gas species were simultaneously monitored in-situ across the combustion flow of the boiler and extractively at the stack. Sensitivity to changes of particulate fume and carryover levels in the process flow were also demonstrated. Boiler set-up and operation is a complex balance of conditions that influence the chemical and physical processes in the combustion flow. Operating parameters include black liquor flow rate, liquor temperature, nozzle pressure, primary air, secondary air, tertiary air, boiler excess oxygen and others. The in-process information provided by the FT-IR monitors can be used as a boiler control tool since species indicative of combustion efficiency (carbon monoxide, methane) and pollutant emissions (sulfur dioxide, hydrochloric acid and fume) were monitored in real-time and observed to fluctuate as operating conditions were varied. A high priority need of the U.S. industrial boiler market is improved measurement and control technology. The sensor technology demonstrated in this project is applicable to the need of industry.

  4. Characterization of additives typically employed in EPDM formulations by using FT-IR of gaseous pyrolyzates

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    Natália Beck Sanches

    2014-06-01

    Full Text Available In this study, Fourier transform infrared spectroscopy (FT-IR was employed to investigate the gaseous pyrolysis products of ethylene - propylene - diene rubber (EPDM. The objective was to evaluate the potential of FT-IR analysis of gaseous pyrolyzates (PY-G/FT-IR for characterization of EPDM additives. Two EPDM formulations, containing additives typically employed in EPDM rubbers, were analyzed. Initially, gaseous pyrolysis products from paraffin oil, stearic acid, 2,2,4-trimethyl-1,2-dihydroquinoline, tetramethylthiuram monosulfide (TMTM, tetramethylthiuram disulfide (TMTD, and 2-mercaptobenzothiazole (MBT were characterized separately, and their main absorptions were identified. Subsequently, the gaseous pyrolysis products of raw, unvulcanized, and vulcanized EPDM formulations were analyzed. The similarities observed in the FT-IR spectra of unvulcanized and vulcanized EPDM show that the vulcanization process does not interfere with the pyrolysis products. The identification of the functional groups of the studied additives was possible in both unvulcanized and vulcanized EPDM samples, without solvent extraction. Results also demonstrate that the PY-G/FT-IR technique can identify additives containing sulfur in concentrations as low as 1.4 phr (1.26% in both unvulcanized and vulcanized EPDM. However, the method showed some limitation due to overlapping and to similarities of TMTM and TMTD PY-G/FT-IR spectra, which could not be distinguished from each other. The PY-G/FT-IR technique is a faster and cheaper alternative to the sophisticated techniques usually applied to detection of additives in rubbers.

  5. Monitoring lipase-catalyzed interesterification for bulky fats modification with FT-IR/NIR spectroscopy

    DEFF Research Database (Denmark)

    Chang, Tinghong; Lai, Xuxin; Zhang, Hong

    2005-01-01

    This work demonstrates the application of FT-IR and FT-NIR spectroscopy to monitor the enzymatic interesterification process for bulky fat modification. The reaction was conducted between palm stearin and coconut oil (70/30, w/w) with the catalysis of Lipozyme TL IM at 70°C in a batch reactor...... (PLS) regression. High correlations (r > 0.96) were obtained from cross validations of the data estimated by FT-IR, FT-NIRand above-mentioned conventional analytical methods, except for correlations (r = 0.90-0,95) between FT-IR and SFC profiles. Overall, FT-NIR spectroscopy coupled with transmission...

  6. Generation of chemical movies: FT-IR spectroscopic imaging of segmented flows.

    Science.gov (United States)

    Chan, K L Andrew; Niu, X; deMello, A J; Kazarian, S G

    2011-05-01

    We have previously demonstrated that FT-IR spectroscopic imaging can be used as a powerful, label-free detection method for studying laminar flows. However, to date, the speed of image acquisition has been too slow for the efficient detection of moving droplets within segmented flow systems. In this paper, we demonstrate the extraction of fast FT-IR images with acquisition times of 50 ms. This approach allows efficient interrogation of segmented flow systems where aqueous droplets move at a speed of 2.5 mm/s. Consecutive FT-IR images separated by 120 ms intervals allow the generation of chemical movies at eight frames per second. The technique has been applied to the study of microfluidic systems containing moving droplets of water in oil and droplets of protein solution in oil. The presented work demonstrates the feasibility of the use of FT-IR imaging to study dynamic systems with subsecond temporal resolution.

  7. Correlation between the FT-IR characteristics and metoprolol tartrate release of methylcellulose-based patches.

    Science.gov (United States)

    Papp, József; Horgos, József; Szente, Virág; Zelkó, Romána

    2010-06-15

    The aim of the present study was to investigate how the drug release and FT-IR characteristics of metolose patches were influenced by the changes of Metolose SM 4000 (methylcellulose) and Metolose 90SH 100.000SR (hypromellose) proportions. FT-IR spectroscopy measurements were performed in parallel with the metoprolol tartrate release study to track the effect of the composition on the drug release. The metoprolol tartrate release profile of the patches was evaluated by Weibull distribution. Linear relationship was found with good correlation between the logarithm of time interval necessary to release 63.2% of metoprolol tartrate (tau(d) values) and the peak area measured within the characteristic FT-IR wavenumbers of patches. The application of FT-IR measurements can be recommended as a rapid, non-destructive screening method during the in-process control of patches.

  8. Application of Fourier-transform infrared (FT-ir) spectroscopy to in-situ studies of coal combustion

    Energy Technology Data Exchange (ETDEWEB)

    Ottesen, D K; Thorne, L R

    1982-04-01

    The feasibility of using Fourier-transform infrared (FT-ir) spectroscopy for in situ measurement of gas phase species concentrations and temperature during coal combustion is examined. This technique is evaluated in terms of its potential ability to monitor several important chemical and physical processes which occur in pulverized coal combustion. FT-ir absorption measurements of highly sooting, gaseous hydrocarbon/air flames are presented to demonstrate the fundamental usefulness of the technique for in situ detection of gas phase temperatures and species concentrations in high temperature combustion environments containing coal, char, mineral matter and soot particles. Preliminary results for coal/gaseous fuel/air flames are given.

  9. Determination of polymer content in energetic materials by FT-IR

    Directory of Open Access Journals (Sweden)

    Elizabeth C. Mattos

    2009-06-01

    Full Text Available A new methodology was developed to characterize and to quantify the polymer content in PBX (HMX/Viton by Fourier Transform Infrared Spectroscopy (FT-IR, using the Termogravimetric analysis (TG as reference techniques for the quantitative method. The quantification methodology, proposed by us, using the Fourier transform infrared-attenuated total reflectance (FT-IR/ATR showed excellent results, being faster than the usual methodologies and can eliminate the generation of chemical residues.

  10. TG/FT-IR characterization of additives typically employed in EPDM formulations

    Directory of Open Access Journals (Sweden)

    Natália Beck Sanches

    2015-06-01

    Full Text Available AbstractThermogravimetric analysis coupled to Fourier transform infrared spectroscopy (TG/FT-IR is a very popular technique for rubbers characterization. It involves analyses of the base polymer and additives. Ethylene–propylene–diene (EPDM rubbers are frequently investigated by TG/FT-IR; however, the focus has been the degradation temperature range of the polymer. In this study, unvulcanized and vulcanized EPDM rubber and its additives were investigated by TG/FT-IR, without solvent extraction, and in a wide temperature range. Initially, the additives were individually characterized. TG/FT-IR identified the characteristic groups of all the additives analyzed and distinguished them from each other. Afterwards, unvulcanized and vulcanized EPDM rubbers were investigated without prior extraction.TG/FT-IR detected absorptions due to the additives tetramethylthiuram monosulfide and 2-mercaptobenzothiazole. Both of these sulfur-containing additives were present in the EPDM formulation at concentrations of 0.7 phr (0.63 wt %. The TG/FT-IR technique had some limitations, because not all the additives in EPDM rubber were detected. Paraffin oil, stearic acid and 2,2,4-trimethyl-1,2-dihydroquinoline functional groups were not observed in either the unvulcanized or vulcanized EPDM. Nevertheless, in addition to the ability of this method to detect sulfur-containing groups, the lack of a pre-extraction reduces the time and effort required for additive analysis in rubbers.

  11. Application of Fourier transform infrared (FT-IR) spectroscopy in determination of microalgal compositions.

    Science.gov (United States)

    Meng, Yingying; Yao, Changhong; Xue, Song; Yang, Haibo

    2014-01-01

    Fourier transform infrared spectroscopy (FT-IR) was applied in algal strain screening and monitoring cell composition dynamics in a marine microalga Isochrysis zhangjiangensis during algal cultivation. The content of lipid, carbohydrate and protein of samples determined by traditional methods had validated the accuracy of FT-IR method. For algal screening, the band absorption ratios of lipid/amide I and carbo/amide I from FT-IR measurements allowed for the selection of Isochrysis sp. and Tetraselmis subcordiformis as the most potential lipid and carbohydrate producers, respectively. The cell composition dynamics of I. zhangjiangensis measured by FT-IR revealed the diversion of carbon allocation from protein to carbohydrate and neutral lipid when nitrogen-replete cells were subjected to nitrogen limitation. The carbo/amide I band absorption ratio had also been demonstrated to depict physiological status under nutrient stress in T. subcordiformis. FT-IR serves as a tool for the simultaneous measurement of lipid, carbohydrate, and protein content in cell.

  12. Fourier Transform Infrared (FT-IR) Spectroscopy of Atmospheric Trace Gases HCl, NO and SO2

    Science.gov (United States)

    Haridass, C.; Aw-Musse, A.; Dowdye, E.; Bandyopadhyay, C.; Misra, P.; Okabe, H.

    1998-01-01

    Fourier Transform Infrared (FT-IR) spectral data have been recorded in the spectral region 400-4000/cm of hydrogen chloride and sulfur dioxide with I/cm resolution and of nitric oxide with 0.25 cm-i resolution, under quasi-static conditions, when the sample gas was passed through tubings of aluminum, copper, stainless steel and teflon. The absorbance was measured for the rotational lines of the fundamental bands of (1)H(35)Cl and (1)H(37)Cl for pressures in the range 100-1000 Torr and for the (14)N(16)O molecule in the range 100-300 Torr. The absorbance was also measured for individual rotational lines corresponding to the three modes of vibrations (upsilon(sub 1) - symmetric stretch, upsilon(sub 2) - symmetric bend, upsilon(sub 3) - anti-symmetric stretch) of the SO2 molecule in the pressure range 25-150 Torr. A graph of absorbance versus pressure was plotted for the observed rotational transitions of the three atmospherically significant molecules, and it was found that the absorbance was linearly proportional to the pressure range chosen, thereby validating Beer's law. The absorption cross-sections were determined from the graphical slopes for each rotational transition recorded for the HCl, NO and SO2 species. Qualitative and quantitative spectral changes in the FT-IR data will be discussed to identify and characterize various tubing materials with respect to their absorption features.

  13. Quantitative determination of pulegone in pennyroyal oil by FT-IR spectroscopy.

    Science.gov (United States)

    Petrakis, Eleftherios A; Kimbaris, Athanasios C; Pappas, Christos S; Tarantilis, Petros A; Polissiou, Moschos G

    2009-11-11

    Pulegone constitutes a monoterpene occurring in Mentha species and primarily in Mentha pulegium L. (pennyroyal). A major source of human exposure to pulegone is the use of pennyroyal essential oil in flavorings, confectionery and cosmetics. The rapid quantification of pulegone in hydrodistilled pennyroyal oils (which were also "spiked" to increase the validation range) by Fourier transform infrared spectroscopy (FT-IR) combined with partial least-squares (PLS) regression was evaluated, using the spectral region 1650-1260 cm(-1). Gas chromatography was applied as the reference method for pennyroyal oil samples, which ranged in pulegone content from 157 to 860 mg/mL. The two methods were subjected to statistical tests and proved equivalent in terms of accuracy and reproducibility (99% confidence level). The use of FT-IR spectroscopy could offer a viable alternative to the standard analysis procedures presently applied for quantification of valuable plant substances and could also provide the processing industry with a simple and high-throughput technique for the fast quality check of incoming raw materials such as pennyroyal oils.

  14. FT-IR Application for the Detection of Pistachio Oil Adulteration

    Directory of Open Access Journals (Sweden)

    Ali Sheibani

    2014-09-01

    Full Text Available In this work, fourier transform infrared spectroscopy (FT-IR is used to identify and detection the adulteration of pistachio oil with cheap edible oils of corn, sunflower and soybean. For this purpose, pistachio oil was blended with cheap oils at concentration level of 10 to 60% (w/w. Then, FT-IR spectra of pure and adulterated pistachio oil samples were obtained. The fingerprints region was found to be useful in investigation of the adulteration of pistachio oil. At this region, the absorbance peaks of FT-IR decreased by increasing the adulterant amount with a linear relation that can be applied for the quality and quantity purposes. The obtained results showed that the proposed method can be considered and used as an alternative method in the detection and semi-quantization of adulteration in pistachio oil.

  15. On-line sample treatment and FT-IR determination of doxylamine succinate in pharmaceuticals.

    Science.gov (United States)

    Ventura-Gayete, Josep F; de la Guardia, Miguel; Garrigues, Salvador

    2006-12-15

    A low solvent consumption method for Fourier transform infrared spectroscopy (FT-IR) determination of doxylamine succinate in pharmaceuticals has been developed. The analyte was continuous and selectively extracted with a 13% (v/v) ethanol:chloroform solvent mixture, recirculating the solvent through the sample and monitoring the process by FT-IR. Doxylamine succinate was determined by on-line standard addition measuring the peak area in the regions 1730-1710 and 1485-1462cm(-1) corrected with a two-point baseline established between 2000 and 1800cm(-1). This new method implies low volumes of chloroformic solvent mixture, only 2.6mL per sample, in front of classical batch FT-IR methods, improving analytical efficiency and reducing waste generation. The on-line extraction and standard addition determination of doxylamine succinate allowed a throughput of 10h(-1).

  16. FOURIER TRANSFORM INFRA RED (FT-IR SPECTRAL STUDIES OF FOENICULUM VULGARE

    Directory of Open Access Journals (Sweden)

    V. Devika

    2013-03-01

    Full Text Available Plants have been used in traditional medicine for several thousand years. Medicinal plants as a group comprise approximately 8000 species and account for about 50% of all the higher flowering plant species in India. In the present study, the plant Foeniculum vulgare was subjected to FT-IR spectroscopy. FT-IR-is a vibrational spectroscopy that records absorptions of IR light by chemical bonds in all molecules incl. polymers. Foeniculum vulgare (Apiaceae commonly known as fennel is a well known and important medicinal and aromatic plant widely used as carminative, digestive, lactogogue and diuretic and in treating respiratory and gastrointestinal disorders. The results showed the detections of the bands in organic molecules. Thus the study became evident that the plant posses some bioactive compounds at various bands obtained after FT-IR.

  17. Study On Gallstone And Bezoar (Ox Gallstone) by FT-IR Spectroscopy

    Science.gov (United States)

    Wu, Jinguang; Shen, Guorong; Guo, Hai; Xu, Guangxian

    1985-12-01

    Some specimens of gallstones with black colour and pigment gallstones were studied by FT-IR spectroscopy. From the subtraction spectra of the samples using calcium bilirubin as the reference substance, the characteristic bands of the proteins were obtained. Bezoar is the gallstone of ox. It is an important ingredient of some Chinese traditional medicines. Four specimens of natural bezoar produced from different places were studied by FT-IR. From the subtraction spectra of the bezoar samples using calcium bilirubin as the reference, the main bands of protein were also obtained. The secondary structures of the proteins were discussed.

  18. Monitoring lipase-catalyzed interesterification for bulky fats modification with FT-IR/NIR spectroscopy

    DEFF Research Database (Denmark)

    Chang, Tinghong; Lai, Xuxin; Zhang, Hong

    2005-01-01

    This work demonstrates the application of FT-IR and FT-NIR spectroscopy to monitor the enzymatic interesterification process for bulky fat modification. The reaction was conducted between palm stearin and coconut oil (70/30, w/w) with the catalysis of Lipozyme TL IM at 70°C in a batch reactor...... (PLS) regression. High correlations (r > 0.96) were obtained from cross validations of the data estimated by FT-IR, FT-NIRand above-mentioned conventional analytical methods, except for correlations (r = 0.90-0,95) between FT-IR and SFC profiles. Overall, FT-NIR spectroscopy coupled with transmission....... The blends and interesterified fats samples in liquid form were measured by attenuated total reflectance (ATR) based FT-IR (spectra region: 1516-781 cm-1) and transmission mode based FT-NIR (spectra region: 5369-4752 cm-1) with temperature both controlled at 70°C. The samples in solid form were also measured...

  19. Preliminary Study on Pyrolysis of Polymethylsilsesquioxane by FT-IR and XPS

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Changes of composition and structure of various samples of polymethylsilsesquioxane (PMSQ) pyrolysed at different temperature under flowing nitrogen were investigated by means of FT-IR and X-ray photoelectron spectroscopy. Two temperature domains correspond to important changes in the chemical composition of PMSQ. The former (Tp 500oC) is associated with the organic-inorgnic transition.

  20. Characterization of Organosolv Lignins using Thermal and FT-IR Spectroscopic Analysis

    Science.gov (United States)

    Rhea J. Sammons; David P. Harper; Nicole Labbe; Joseph J. Bozell; Thomas Elder; Timothy G. Rials

    2013-01-01

    A group of biomass-derived lignins isolated using organosolv fractionation was characterized by FT-IR spectral and thermal property analysis coupled with multivariate analysis. The principal component analysis indicated that there were significant variations between the hardwood, softwood, and grass lignins due to the differences in syringyl and guaiacyl units as well...

  1. Collaborative Student Laboratory Exercise Using FT-IR Spectroscopy for the Kinetics Study of a Biotin Analogue

    Science.gov (United States)

    Leong, Jhaque; Ackroyd, Nathan C.; Ho, Karen

    2014-01-01

    The synthesis of N-methoxycarbonyl-2-imidazolidone, an analogue of biotin, was conducted by organic chemistry students and confirmed using FT-IR and H NMR. Spectroscopy students used FT-IR to measure the rate of hydrolysis of the product and determined the rate constant for the reaction using the integrated rate law. From the magnitude of the rate…

  2. FT-IR, RAMAN AND DFT STUDIES ON THE VIBRATIONAL ...

    African Journals Online (AJOL)

    KEY WORDS: 2,2-Bis(aminoethoxy)propane, IR spectra, Raman spectra, ... were first optimized by B3LYP with 6-311G++(d,p) basis set in the gas phase. .... Molecular electronic polarizability of symmetric vibrational form of NH2 changes more ...

  3. Analysis and Assessment of Agrimonia Pilosa Ledeb from Different Sources Using FT-IR Spectroscopy

    Institute of Scientific and Technical Information of China (English)

    Bao-qing WANG; Zhe-xiong JIN

    2010-01-01

    To get the IR spectrums of Agrimonia Pilosa Ledeb (APL) from China and Japan areas,and to find out the characters of IR spectrums through the content of different chemical constituents,to provide a fast and effective analysis method monitor the inherent qualities of traditional Chinese medicine-APL.Fourier Transform Infrared Spectroscopy(FT-IR) was applied to detect sample of APL from China and Japan areas.This study showed that the IR spectra of APL from China and Japan areas have their unique IR fingerprint features.The contents of tannin and calcium phosphate in APL from China is different APL from Japan.So FT-IR is a very quick,effective and well repetitive method for monitoring and distinguishing the traditional Chinese medicine.

  4. Characterization of human ovarian teratoma hair by using AFM, FT-IR, and Raman spectroscopy.

    Science.gov (United States)

    Kim, Kyung Sook; Lee, Jinwoo; Jung, Min-Hyung; Choi, Young Joon; Park, Hun-Kuk

    2011-12-01

    The structural, physical, and chemical properties of hair taken from an ovarian teratoma (teratoma hair) was first examined by atomic force microscopy (AFM), Fourier transform infrared (FT-IR), and Raman spectroscopy. The similarities and differences between the teratoma hair and scalp hair were also investigated. Teratoma hair showed a similar morphology and chemical composition to scalp hair. Teratoma hair was covered with a cuticle in the same manner as scalp hair and showed the same amide bonding modes as scalp hair according to FT-IR and Raman spectroscopy. On the other hand, teratoma hair showed different physical properties and cysteic acid bands from scalp hair: the surface was rougher and the adhesive force was lower than the scalp hair. The cystine oxides modes did not change with the position unlike scalp hair. These differences can be understood by environmental effects not by the intrinsic properties of the teratoma hair.

  5. Characterization of the crystalline structure of cellulose using static and dynamic FT-IR spectroscopy.

    Science.gov (United States)

    Akerholm, Margaretha; Hinterstoisser, Barbara; Salmén, Lennart

    2004-02-25

    The cellulose structure is a factor of major importance for the strength properties of wood pulp fibers. The ability to characterize small differences in the crystalline structures of cellulose from fibers of different origins is thus highly important. In this work, dynamic FT-IR spectroscopy has been further explored as a method sensitive to cellulose structure variations. Using a model system of two different celluloses, the relation between spectral information and the relative cellulose Ialpha content was investigated. This relation was then used to determine the relative cellulose Ialpha content in different pulps. The estimated cellulose I allomorph compositions were found to be reasonable for both unbleached and bleached chemical pulps. In addition, it was found that the dynamic FT-IR spectroscopy technique had the potential to indicate possible correlation field splitting peaks of cellulose Ibeta.

  6. Study of the Pyrrol/Diphenylamine Copolymer by FT-IR spectroscopy and conductivity

    Directory of Open Access Journals (Sweden)

    Carlos Alberto Perez

    2004-01-01

    Full Text Available The main goal of this study was to analyze the physical properties of the copolymer formed by the electrochemical deposition of the polydiphenylamine (PDPA on polypyrrole (Ppy and Ppy on PDPA, in different conditions, through the characterization of the materials formed by the resonant Raman, FT-IR and conductivity techniques. The interactions among the species which are present in the new copolymer structure and the changes in electronic conductivity, were verified. The copolymer was also synthesized electrochemically in the presence of iodide species and the material was characterized by FT-IR spectroscopy and conductivity. The role of the dopant was studied in the process of charge transfer between the copolymer-dopant, acting in the stabilization of the species in the polymer backbone and the increase of the electronic conductivity.

  7. Electron paramagnetic resonance and FT-IR spectroscopic studies of glycine anhydride and betaine hydrochloride

    Science.gov (United States)

    Halim Başkan, M.; Kartal, Zeki; Aydın, Murat

    2015-12-01

    Gamma irradiated powders of glycine anhydride and betaine hydrochloride have been investigated at room temperature by electron paramagnetic resonance (EPR). In these compounds, the observed paramagnetic species were attributed to the R1 and R2 radicals, respectively. It was determined that the free electron interacted with environmental protons and 14N nucleus in both radicals. The EPR spectra of gamma irradiated powder samples remained unchanged at room temperature for two weeks after irradiation. Also, the Fourier Transform Infrared (FT-IR), FT-Raman and thermal analyses of both compounds were investigated. The functional groups in the molecular structures of glycine anhydride and betaine hydrochloride were identified by vibrational spectroscopies (FT-IR and FT-Raman).

  8. FT-IR and FT-NIR Raman spectroscopy in biomedical research

    Science.gov (United States)

    Naumann, D.

    1998-06-01

    FT-IR and FT-NIR Raman spectra of intact microbial, plant animal or human cells, tissues, and body fluids are highly specific, fingerprint-like signatures which can be used to discriminate between diverse microbial species and strains, characterize growth-dependent phenomena and cell-drug interactions, and differentiate between various disease states. The spectral information potentially useful for biomedical characterizations may be distributed over the entire infrared region of the electromagnetic spectrum, i.e. over the near-, mid-, and far-infrared. It is therefore a key problem how the characteristic vibrational spectroscopic information can be systematically extracted from the infrared spectra of complex biological samples. In this report these questions are addressed by applying factor and cluster analysis treating the classification problem of microbial infrared spectra as a model task. Particularly interesting applications arise by means of a light microscope coupled to the FT-IR spectrometer. FT-IR spectra of single microcolonies of less than 40 μm in diameter can be obtained from colony replica applying a stamping technique that transfers the different, spatially separated microcolonies from the culture plate to a special IR-sample holder. Using a computer controlled x,y-stage together with mapping and video techniques, the fundamental tasks of microbiological analysis, namely detection, enumeration, and differentiation of micro-organisms can be integrated in one single apparatus. Since high quality, essentially fluorescence free Raman spectra may now be obtained in relatively short time intervals on previously intractable biological specimens, FT-IR and NIR-FT-Raman spectroscopy can be used in tandem to characterize biological samples. This approach seems to open up new horizons for biomedical characterizations of complex biological systems.

  9. Changes in liver cell DNA methylation status in diabetic mice affect its FT-IR characteristics.

    Directory of Open Access Journals (Sweden)

    Benedicto de Campos Vidal

    Full Text Available Lower levels of cytosine methylation have been found in the liver cell DNA from non-obese diabetic (NOD mice under hyperglycemic conditions. Because the Fourier transform-infrared (FT-IR profiles of dry DNA samples are differently affected by DNA base composition, single-stranded form and histone binding, it is expected that the methylation status in the DNA could also affect its FT-IR profile.The DNA FT-IR signatures obtained from the liver cell nuclei of hyperglycemic and normoglycemic NOD mice of the same age were compared. Dried DNA samples were examined in an IR microspectroscope equipped with an all-reflecting objective (ARO and adequate software.Changes in DNA cytosine methylation levels induced by hyperglycemia in mouse liver cells produced changes in the respective DNA FT-IR profiles, revealing modifications to the vibrational intensities and frequencies of several chemical markers, including νas -CH3 stretching vibrations in the 5-methylcytosine methyl group. A smaller band area reflecting lower energy absorbed in the DNA was found in the hyperglycemic mice and assumed to be related to the lower levels of -CH3 groups. Other spectral differences were found at 1700-1500 cm(-1 and in the fingerprint region, and a slight change in the DNA conformation at the lower DNA methylation levels was suggested for the hyperglycemic mice. The changes that affect cytosine methylation levels certainly affect the DNA-protein interactions and, consequently, gene expression in liver cells from the hyperglycemic NOD mice.

  10. The Utilization of FT-IR for Army Oil Condition Monitoring

    Science.gov (United States)

    1998-01-01

    partial combustion and distillation of lighter components. FT-IR determines fuel contamination by measuring the absorbance bands of specific...of different compounds, additives and reformates. A marker band typical in fuel contaminated oil samples was found at 810 cm". This absorbance band is...a flammable solvent, is used to clean the transmission cell between samples. One Army base suggested a terpene based, non-flammable solvent, Electron

  11. High-definition Fourier Transform Infrared (FT-IR) spectroscopic imaging of human tissue sections towards improving pathology.

    Science.gov (United States)

    Sreedhar, Hari; Varma, Vishal K; Nguyen, Peter L; Davidson, Bennett; Akkina, Sanjeev; Guzman, Grace; Setty, Suman; Kajdacsy-Balla, Andre; Walsh, Michael J

    2015-01-21

    High-definition Fourier Transform Infrared (FT-IR) spectroscopic imaging is an emerging approach to obtain detailed images that have associated biochemical information. FT-IR imaging of tissue is based on the principle that different regions of the mid-infrared are absorbed by different chemical bonds (e.g., C=O, C-H, N-H) within cells or tissue that can then be related to the presence and composition of biomolecules (e.g., lipids, DNA, glycogen, protein, collagen). In an FT-IR image, every pixel within the image comprises an entire Infrared (IR) spectrum that can give information on the biochemical status of the cells that can then be exploited for cell-type or disease-type classification. In this paper, we show: how to obtain IR images from human tissues using an FT-IR system, how to modify existing instrumentation to allow for high-definition imaging capabilities, and how to visualize FT-IR images. We then present some applications of FT-IR for pathology using the liver and kidney as examples. FT-IR imaging holds exciting applications in providing a novel route to obtain biochemical information from cells and tissue in an entirely label-free non-perturbing route towards giving new insight into biomolecular changes as part of disease processes. Additionally, this biochemical information can potentially allow for objective and automated analysis of certain aspects of disease diagnosis.

  12. Detection of metanil yellow contamination in turmeric using FT-Raman and FT-IR spectroscopy

    Science.gov (United States)

    Dhakal, Sagar; Chao, Kuanglin; Qin, Jianwei; Kim, Moon; Schmidt, Walter; Chan, Dian

    2016-05-01

    Turmeric is well known for its medicinal value and is often used in Asian cuisine. Economically motivated contamination of turmeric by chemicals such as metanil yellow has been repeatedly reported. Although traditional technologies can detect such contaminants in food, high operational costs and operational complexities have limited their use to the laboratory. This study used Fourier Transform Raman Spectroscopy (FT-Raman) and Fourier Transform - Infrared Spectroscopy (FT-IR) to identify metanil yellow contamination in turmeric powder. Mixtures of metanil yellow in turmeric were prepared at concentrations of 30%, 25%, 20%, 15%, 10%, 5%, 1% and 0.01% (w/w). The FT-Raman and FT-IR spectral signal of pure turmeric powder, pure metanil yellow powder and the 8 sample mixtures were obtained and analyzed independently to identify metanil yellow contamination in turmeric. The results show that FT-Raman spectroscopy and FT-IR spectroscopy can detect metanil yellow mixed with turmeric at concentrations as low as 1% and 5%, respectively, and may be useful for non-destructive detection of adulterated turmeric powder.

  13. Detection of starch adulteration in onion powder by FT-NIR and FT-IR spectroscopy.

    Science.gov (United States)

    Lohumi, Santosh; Lee, Sangdae; Lee, Wang-Hee; Kim, Moon S; Mo, Changyeun; Bae, Hanhong; Cho, Byoung-Kwan

    2014-09-24

    Adulteration of onion powder with cornstarch was identified by Fourier transform near-infrared (FT-NIR) and Fourier transform infrared (FT-IR) spectroscopy. The reflectance spectra of 180 pure and adulterated samples (1-35 wt % starch) were collected and preprocessed to generate calibration and prediction sets. A multivariate calibration model of partial least-squares regression (PLSR) was executed on the pretreated spectra to predict the presence of starch. The PLSR model predicted adulteration with an R(p)2 of 0.98 and a standard error of prediction (SEP) of 1.18% for the FT-NIR data and an R(p)2 of 0.90 and SEP of 3.12% for the FT-IR data. Thus, the FT-NIR data were of greater predictive value than the FT-IR data. Principal component analysis on the preprocessed data identified the onion powder in terms of added starch. The first three principal component loadings and β coefficients of the PLSR model revealed starch-related absorption. These methods can be applied to rapidly detect adulteration in other spices.

  14. Identification of species' blood by attenuated total reflection (ATR) Fourier transform infrared (FT-IR) spectroscopy.

    Science.gov (United States)

    Mistek, Ewelina; Lednev, Igor K

    2015-09-01

    Blood is one of the most common and informative forms of biological evidence found at a crime scene. A very crucial step in forensic investigations is identifying a blood stain's origin. The standard methods currently employed for analyzing blood are destructive to the sample and time-consuming. In this study, attenuated total reflection (ATR) Fourier transform infrared (FT-IR) spectroscopy is used as a confirmatory, nondestructive, and rapid method for distinction between human and animal (nonhuman) blood. Partial least squares-discriminant analysis (PLS-DA) models were built and demonstrated complete separation between human and animal donors, as well as distinction between three separate species: human, cat, and dog. Classification predictions of unknown blood donors were performed by the model, resulting in 100 % accuracy. This study demonstrates ATR FT-IR spectroscopy's great potential for blood stain analysis and species discrimination, both in the lab and at a crime scene since portable ATR FT-IR instrumentation is commercially available.

  15. The detection and discrimination of human body fluids using ATR FT-IR spectroscopy.

    Science.gov (United States)

    Orphanou, Charlotte-Maria; Walton-Williams, Laura; Mountain, Harry; Cassella, John

    2015-07-01

    Blood, saliva, semen and vaginal secretions are the main human body fluids encountered at crime scenes. Currently presumptive tests are routinely utilised to indicate the presence of body fluids, although these are often subject to false positives and limited to particular body fluids. Over the last decade more sensitive and specific body fluid identification methods have been explored, such as mRNA analysis and proteomics, although these are not yet appropriate for routine application. This research investigated the application of ATR FT-IR spectroscopy for the detection and discrimination of human blood, saliva, semen and vaginal secretions. The results demonstrated that ATR FT-IR spectroscopy can detect and distinguish between these body fluids based on the unique spectral pattern, combination of peaks and peak frequencies corresponding to the macromolecule groups common within biological material. Comparisons with known abundant proteins relevant to each body fluid were also analysed to enable specific peaks to be attributed to the relevant protein components, which further reinforced the discrimination and identification of each body fluid. Overall, this preliminary research has demonstrated the potential for ATR FT-IR spectroscopy to be utilised in the routine confirmatory screening of biological evidence due to its quick and robust application within forensic science.

  16. Applications of FT-IR spectrometry to plasma contents analysis and monitoring

    Science.gov (United States)

    Deleris, Gerard Y. R.; Petibois, Cyril

    2002-03-01

    We devoted efforts to develop an analytical method of plasma able to provide both a high sensitivity and a global overview of its biomolecular contents along with the variations of these ones. Among candidates, transmittance FT-IR spectrometry has proved to be highly efficient. It has been used to analyze plasma micro samples using an iterative process. Results in accordance with clinical data were obtained from a single FT-IR spectrum for the following biomolecules: amino-acids, fatty acids, albumin, glucose, fibrinogen, lactate, triglycerides, glycerol, urea, (alpha) 1-antitrypsin, alpha2-macroglobulin, transferin, Apo-A1, Apo-B, Apo-C3, IgA, IgD, IgG1, IgG2, IgG3, IgG4, IgM, haptoglobin, and (alpha) 1-acid glycoprotein. Moreover, cholesterol contribution may be determined on the same IR spectrum. Therefore, as only micro samples are necessary, high frequency blood analysis become available. This method was used to monitor inflammatory processes related to given metabolic stresses. Moreover, FT-IR spectrum constitutes a 'metabolic photography' of the subject, allowing classification between metabolic groups (pathologic or others). It was used on difference spectra in order to raise 'signal to noise' ratio by elimination of the unvarying spectral contribution. Among others, it allowed to uncover overtraining in high-level sportsmen several weeks before any physiologic or clinical symptom occurred.

  17. DIFERENCIACIÓN DE ESPECIE MICOBACTERIANA POR FT-IR (ESPECTROSCOPIA INFRARROJA CON TRANSFORMADA DE FOURIER Differentiation of Mycobacterial Species by FT-IR (Fourier Transform Infrared Spectroscopy

    Directory of Open Access Journals (Sweden)

    JORGE ANDRÉS CUÉLLAR GIL

    2011-08-01

    Full Text Available Se trabajó con espectroscopía infrarroja transformada de Fourier (FT-IR para diferenciar diez especies de micobacterias. Mycobacterium intracelullare y M. fortuitum (ATCC, M. flavensces, M. smegmatis, M. chelone, M. gordonae, M. triviale, M. vaccae, M. terrae y M. nonchromogenicum (IP. Como control de diferenciación de género se incluyó Staphylococcus aureus, Streptococcus viridans y Streptococcus pyogenes, Klebsiella pneumoniae y Escherichia coli, cada especie se corrió por triplicado en KBr y ATR. Los espectros se analizaron según el método de diferenciación de componentes principales, y se realizaron derivadas de primer orden (D1 en modalidad de transmisión usando la pastilla de KBr y la base ATR, además se diseñó una biblioteca espectral con la primera derivada de ATR. La sensibilidad de detección fue de 100% al trabajar con KBr y el nivel de diferenciación fue de 100% en tres de cuatro muestras problema.Spectroscopy Fourier Transform infrared (FT-IR was used to differentiate 10 species of mycobacteria. Mycobacterium intracelullare and M. fortuitum (ATCC. M. flavensces, M. smegmatis, M. chelone, M. gordonae, M. triviale, M. vaccae, M. terrae and M. nonchromogenicum (IP. For gender differentiation Staphylococcus aureus, Streptococcus viridans and Streptococcus pyogenes, Klebsiella pneumoniae y Escherichia coli were incluided as controls, each species was run for triplicate in KBr and ATR. The spectra were analyzed with the method of principal components to make the first derivatives of first order (D1 in the transmission mode using KBr pellet and ATR base, and a spectral library of the first derivative of ATR was kept. The detection sensitivity was 100% with KBr and the level of differentiation was 100% in three of the four samples problems.

  18. Mineralogical Characterization Studies on Unburnt Ceramic Product Made from Rock Residue Additives by Ft-Ir Spectroscopic Technique

    Science.gov (United States)

    Vijayaragavan, R.; Mullainathan, S.; Balachandramohan, M.; Krishnamoorthy, N.; Nithiyanantham, S.; Murugesan, S.; Vanathi, V.

    2013-10-01

    The usability of waste rock (rock residue) powder as an additive material in ceramic samples was investigated. Qualitative analysis was carried out to determine the major and minor constituent minerals present in ceramic bodies made from rock residue powder by using FT-IR spectroscopic technique. Further, the representative ceramic bodies are analyzed by FT-IR technique to yield more information about the functional groups and also to estimate the order or disorder of kaolinite structure.

  19. Real-time feedback control using online attenuated total reflection Fourier transform infrared (ATR FT-IR) spectroscopy for continuous flow optimization and process knowledge.

    Science.gov (United States)

    Skilton, Ryan A; Parrott, Andrew J; George, Michael W; Poliakoff, Martyn; Bourne, Richard A

    2013-10-01

    The use of automated continuous flow reactors is described, with real-time online Fourier transform infrared spectroscopy (FT-IR) analysis to enable rapid optimization of reaction yield using a self-optimizing feedback algorithm. This technique has been applied to the solvent-free methylation of 1-pentanol with dimethyl carbonate using a γ-alumina catalyst. Calibration of the FT-IR signal was performed using gas chromatography to enable quantification of yield over a wide variety of flow rates and temperatures. The use of FT-IR as a real-time analytical technique resulted in an order of magnitude reduction in the time and materials required compared to previous studies. This permitted a wide exploration of the parameter space to provide process understanding and validation of the optimization algorithms.

  20. FT-IR Analysis of Urinary Stones: A Helpful Tool for Clinician Comparison with the Chemical Spot Test

    Directory of Open Access Journals (Sweden)

    Aniello Primiano

    2014-01-01

    Full Text Available Background. Kidney stones are a common illness with multifactorial etiopathogenesis. The determination of crystalline and molecular composition and the quantification of all stone components are important to establish the etiology of stones disease but it is often laborious to obtain using the chemical method. The aim of this paper is to compare chemical spot test with FT-IR spectroscopy, for a possible introduction in our laboratory. Methods. We analyzed 48 calculi using Urinary Calculi Analysis kit in accordance with the manufacturer’s instructions. The same samples were analyzed by FT-IR using the Perkin Elmer Spectrum One FT-IR Spectrometer. All FT-IR spectra of kidney stones were then computer matched against a library of spectra to generate a report on the various components. Results. On the basis of FT-IR analysis, the 48 calculi were divided into three groups: pure stone, mixed stone, and pure stone with substances in trace. Results of each group were compared with those obtained with chemical spot test. A general disagreement between methods was observed. Conclusions. According to our data, the introduction of the FT-IR technique in clinical chemistry laboratory may be more responsive to clinician expectations.

  1. FT-IR Analysis of Urinary Stones: A Helpful Tool for Clinician Comparison with the Chemical Spot Test

    Science.gov (United States)

    Primiano, Aniello; D'Addessi, Alessandro; Cocci, Andrea; Schiattarella, Arcangelo; Zuppi, Cecilia

    2014-01-01

    Background. Kidney stones are a common illness with multifactorial etiopathogenesis. The determination of crystalline and molecular composition and the quantification of all stone components are important to establish the etiology of stones disease but it is often laborious to obtain using the chemical method. The aim of this paper is to compare chemical spot test with FT-IR spectroscopy, for a possible introduction in our laboratory. Methods. We analyzed 48 calculi using Urinary Calculi Analysis kit in accordance with the manufacturer's instructions. The same samples were analyzed by FT-IR using the Perkin Elmer Spectrum One FT-IR Spectrometer. All FT-IR spectra of kidney stones were then computer matched against a library of spectra to generate a report on the various components. Results. On the basis of FT-IR analysis, the 48 calculi were divided into three groups: pure stone, mixed stone, and pure stone with substances in trace. Results of each group were compared with those obtained with chemical spot test. A general disagreement between methods was observed. Conclusions. According to our data, the introduction of the FT-IR technique in clinical chemistry laboratory may be more responsive to clinician expectations. PMID:24868112

  2. Evaluation of Polymerization Efficacy in Composite Resins via FT-IR Spectroscopy and Vickers Microhardness Test.

    Science.gov (United States)

    Jafarzadeh, Tahereh-Sadat; Erfan, Mohammad; Behroozibakhsh, Marjan; Fatemi, Mostafa; Masaeli, Reza; Rezaei, Yashar; Bagheri, Hossein; Erfan, Yasaman

    2015-01-01

    Background and aims. Polymerization efficacy affects the properties and performance of composite resin restorations.The purpose of this study was to evaluate the effectiveness of polymerization of two micro-hybrid, two nano-hybrid and one nano-filled ormocer-based composite resins, cured by two different light-curing systems, using Fourier transformation infrared (FT-IR) spectroscopy and Vickers microhardness testing at two different depths (top surface, 2 mm). Materials and methods. For FT-IR spectrometry, five cylindrical specimens (5mm in diameter × 2 mm in length) were prepared from each composite resin using Teflon molds and polymerized for 20 seconds. Then, 70-μm wafers were sectioned at the top surface and at2mm from the top surface. The degree of conversion for each sample was calculated using FT-IR spectroscopy. For Vickers micro-hardness testing, three cylindrical specimens were prepared from each composite resin and polymerized for 20 seconds. The Vickers microhardness test (Shimadzu, Type M, Japan) was performed at the top and bottom (depth=2 mm) surfaces of each specimen. Three-way ANOVA with independent variables and Tukey tests were performed at 95% significance level. Results. No significant differences were detected in degree of conversion and microhardness between LED and QTH light-curing units except for the ormocer-based specimen, CeramX, which exhibited significantly higher DC by LED. All the composite resins showed a significantly higher degree of conversion at the surface. Microhardness was not significantly affected by depth, except for Herculite XRV Ultra and CeramX, which showed higher values at the surface. Conclusion. Composite resins containing nano-particles generally exhibited more variations in degree of conversion and microhardness.

  3. Evaluation of Polymerization Efficacy in Composite Resins via FT-IR Spectroscopy and Vickers Microhardness Test

    Science.gov (United States)

    Jafarzadeh, Tahereh-Sadat; Erfan, Mohammad; Behroozibakhsh, Marjan; Fatemi, Mostafa; Masaeli, Reza; Rezaei, Yashar; Bagheri, Hossein; Erfan, Yasaman

    2015-01-01

    Background and aims. Polymerization efficacy affects the properties and performance of composite resin restorations.The purpose of this study was to evaluate the effectiveness of polymerization of two micro-hybrid, two nano-hybrid and one nano-filled ormocer-based composite resins, cured by two different light-curing systems, using Fourier transformation infrared (FT-IR) spectroscopy and Vickers microhardness testing at two different depths (top surface, 2 mm). Materials and methods. For FT-IR spectrometry, five cylindrical specimens (5mm in diameter × 2 mm in length) were prepared from each composite resin using Teflon molds and polymerized for 20 seconds. Then, 70-μm wafers were sectioned at the top surface and at2mm from the top surface. The degree of conversion for each sample was calculated using FT-IR spectroscopy. For Vickers micro-hardness testing, three cylindrical specimens were prepared from each composite resin and polymerized for 20 seconds. The Vickers microhardness test (Shimadzu, Type M, Japan) was performed at the top and bottom (depth=2 mm) surfaces of each specimen. Three-way ANOVA with independent variables and Tukey tests were performed at 95% significance level. Results. No significant differences were detected in degree of conversion and microhardness between LED and QTH light-curing units except for the ormocer-based specimen, CeramX, which exhibited significantly higher DC by LED. All the composite resins showed a significantly higher degree of conversion at the surface. Microhardness was not significantly affected by depth, except for Herculite XRV Ultra and CeramX, which showed higher values at the surface. Conclusion. Composite resins containing nano-particles generally exhibited more variations in degree of conversion and microhardness. PMID:26889359

  4. Spatial metabolic fingerprinting using FT-IR spectroscopy: investigating abiotic stresses on Micrasterias hardyi.

    Science.gov (United States)

    Patel, Soyab A; Currie, Felicity; Thakker, Nalin; Goodacre, Royston

    2008-12-01

    The release of active pharmaceutical ingredients (APIs) into the environment is an ecologically important topic for study because, whilst APIs have been designed to have a wide range of biological properties for the target of interest (usually in man), little information on potential ecological risks is currently available regarding their effects on the organisms that inhabit the environment. In this study, the algae Micrasterias hardyi was exposed to propranolol, metoprolol (beta-adrenergic receptor agonist drugs) and mefenamic acid (a non steroidal anti-inflammatory drug), at concentrations ranging between 0.002-0.2 mM. Initial studies showed that Fourier transform infrared (FT-IR) spectroscopy on algal homogenates illustrated that all three APIs had a quantitative effect on the metabolism of the organisms and it was possible to estimate the level of API exposure from the FT-IR metabolic fingerprints using partial least squares (PLS) regression. From the inspection of the PLS loadings matrices it was possible to elucidate that all drugs caused effects on protein and lipid levels. Most strikingly propranolol had significant effects on the lipid components of the cell. These were dramatically reduced possibly as a consequence of loss of membrane integrity. In order to investigate this further, FT-IR microspectroscopy was used to generate detailed metabolic fingerprinting maps. These chemical maps revealed that all the drugs had a dramatic effect on the distribution of various chemical species throughout the algae, and that all drugs had an affect on protein and lipid levels. In particular, as noted in the PLS analyses for propranolol treated cells, the lipid complement found in the lipid storage areas in the processes of M. hardyi was greatly reduced. This illustrates the power of spatial metabolic fingerprinting for investigating abiotic stresses on complex biological species.

  5. Evaluation of Polymerization Efficacy in Composite Resins via FT-IR Spectroscopy and Vickers Microhardness Test

    Directory of Open Access Journals (Sweden)

    Tahereh-Sadat Jafarzadeh

    2015-12-01

    Full Text Available Background and aims. Polymerization efficacy affects the properties and performance of composite resin restorations.The purpose of this study was to evaluate the effectiveness of polymerization of two micro-hybrid, two nano-hybrid and one nano-filled ormocer-based composite resins, cured by two different light-curing systems, using Fourier transformation infrared (FT-IR spectroscopy and Vickers microhardness testing at two different depths (top surface, 2 mm. Materials and methods. For FT-IR spectrometry, five cylindrical specimens (5mm in diameter × 2 mm in length were prepared from each composite resin using Teflon molds and polymerized for 20 seconds. Then, 70-μm wafers were sectioned at the top surface and at2mm from the top surface. The degree of conversion for each sample was calculated using FT-IR spectroscopy. For Vickers micro-hardness testing, three cylindrical specimens were prepared from each composite resin and polymerized for 20 seconds. The Vickers microhardness test (Shimadzu, Type M, Japan was performed at the top and bottom (depth=2 mm surfaces of each specimen. Three-way ANOVA with independent variables and Tukey tests were performed at 95% significance level. Results. No significant differences were detected in degree of conversion and microhardness between LED and QTH light-curing units except for the ormocer-based specimen, CeramX, which exhibited significantly higher DC by LED. All the composite resins showed a significantly higher degree of conversion at the surface. Microhardness was not significantly affected by depth, except for Herculite XRV Ultra and CeramX, which showed higher values at the surface. Conclusion. Composite resins containing nano-particles generally exhibited more variations in degree of conversion and microhardness.

  6. Utility of FT-IR imaging spectroscopy in estimating differences between the quality of bovine blastocysts

    Science.gov (United States)

    Wiecheć, A.; Opiela, J.; Lipiec, E.; Kwiatek, W. M.

    2013-10-01

    This study was conducted to verify whether the FT-IR spectroscopy and Focal Plane Array (FPA) imaging can be successfully applied to estimate the quality of bovine blastocysts (on the basis of the concentration of nucleic acids and amides). The FT-IR spectra of inner cell mass from blastocysts of three different culture systems were examined. The spectral changes between blastocysts were analyzed in DNA (spectral range of 1240-950 cm-1) and protein amides (1800-1400 cm-1). Blastocyst 1 (BL1-HA) was developed from the fertilized oocyte cultured with low concentration of hialuronian (HA), Blastocyst 2 and 3 were developed from the oocytes cultured in standard conditions. Cleavage stage blastocyst 2 (BL2-SOF) has been cultured in SOF medium while blastocyst 3 (BL3-VERO) was cultured in co-culture with VERO cells. The multivariate statistical analysis (Hierarchical Cluster Analysis - HCA and Principal Component Analysis - PCA) of single cells spectra showed high similarity of cells forming the inner cell mass within single blastocyst. The main variance between the three examined blastocysts was related to amides bands. Differences in the intensities of the amides' peaks between the bovine blastocysts derived from different culture systems indicated that specific proteins reflecting the appearance of a new phenotype were produced. However, for the three blastocysts, the α-helix typical peak was twice more intensive than the β-sheet typical peak suggesting that the differentiation processes had been started. Taking into account the quantitative and qualitative composition of the protein into examined blastocysts, it can be assumed, that the quality of the BL1-HA turned out much more similar to BL3-VERO than to BL2-SOF. FT-IR spectroscopy can be successfully applied in reproductive biology research for quality estimation of oocytes and embryos at varied stages of their development. Moreover this technique proved to be particularly useful when the quantity of the

  7. Using FT-IR Spectroscopy to Elucidate the Structures of Ablative Polymers

    Science.gov (United States)

    Fan, Wendy

    2011-01-01

    The composition and structure of an ablative polymer has a multifaceted influence on its thermal, mechanical and ablative properties. Understanding the molecular level information is critical to the optimization of material performance because it helps to establish correlations with the macroscopic properties of the material, the so-called structure-property relationship. Moreover, accurate information of molecular structures is also essential to predict the thermal decomposition pathways as well as to identify decomposition species that are fundamentally important to modeling work. In this presentation, I will describe the use of infrared transmission spectroscopy (FT-IR) as a convenient tool to aid the discovery and development of thermal protection system materials.

  8. FT-IR spectroscopic analysis for studying Clostridium cell response to conversion of enzymatically hydrolyzed hay

    Science.gov (United States)

    Grube, Mara; Gavare, Marita; Nescerecka, Alina; Tihomirova, Kristina; Mezule, Linda; Juhna, Talis

    2013-07-01

    Grass hay is one of assailable cellulose containing non-food agricultural wastes that can be used as a carbohydrate source by microorganisms producing biofuels. In this study three Clostridium strains Clostridium acetobutylicum, Clostridium beijerinckii and Clostridium tetanomorphum, capable of producing acetone, butanol and ethanol (ABE) were adapted to convert enzymatically hydrolyzed hay used as a growth media additive. The results of growth curves, substrate degradation kinetics and FT-IR analyses of bacterial biomass macromolecular composition showed diverse strain-specific cell response to the growth medium composition.

  9. DETERMINATION OF OXALATE ION DOPANT LEVEL IN POLYPYRROLE USING FT-IR.

    Science.gov (United States)

    Miller, Eric T; Benally, Kristal J; GreyEyes, Shawn D; McKenzie, Jason T

    A pellet method using standard addition and FT-IR was used to estimate oxalate ion doping levels in electrosynthesized polypyrrole. The method is useful for materials where removal of analyte from an insoluble material is problematic. Here, electrosynthesized oxalate doped polypyrrole is dispersed in potassium bromide. Spikes of sodium oxalate are added and the mixtures pressed into pellets. The oxalate carbonyl absorption peak is then used to quantify the amount of oxalate present in the polypyrrole. The mass fraction of oxalate dopant in polypyrrole was determined to be 0.4 ± 0.1 % and coincides with the original synthesis solution composition.

  10. Authenticity study of Phyllanthus species by NMR and FT-IR techniques coupled with chemometric methods

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Maiara S.; Pereira-Filho, Edenir R.; Ferreira, Antonio G. [Universidade Federal de Sao Carlos (UFSCAR), SP (Brazil). Dept. de Quimica; Boffo, Elisangela F. [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil). Inst. de Quimica; Figueira, Glyn M., E-mail: maiarassantos@yahoo.com.br [Universidade Estadual de Campinas (UNICAMP), Campinas, SP (Brazil). Centro Pluridisciplinar de Pesquisas Quimicas, Biologicas e Agricolas

    2012-07-01

    The importance of medicinal plants and their use in industrial applications is increasing worldwide, especially in Brazil. Phyllanthus species, popularly known as 'quebra-pedras' in Brazil, are used in folk medicine for treating urinary infections and renal calculus. This paper reports an authenticity study, based on herbal drugs from Phyllanthus species, involving commercial and authentic samples using spectroscopic techniques: FT-IR, {sup 1}H HR-MAS NMR and {sup 1}H NMR in solution, combined with chemometric analysis. The spectroscopic techniques evaluated, coupled with chemometric methods, have great potential in the investigation of complex matrices. Furthermore, several metabolites were identified by the NMR techniques. (author)

  11. Authenticity study of Phyllanthus species by NMR and FT-IR Techniques coupled with chemometric methods

    Directory of Open Access Journals (Sweden)

    Maiara S. Santos

    2012-01-01

    Full Text Available The importance of medicinal plants and their use in industrial applications is increasing worldwide, especially in Brazil. Phyllanthus species, popularly known as "quebra-pedras" in Brazil, are used in folk medicine for treating urinary infections and renal calculus. This paper reports an authenticity study, based on herbal drugs from Phyllanthus species, involving commercial and authentic samples using spectroscopic techniques: FT-IR, ¹H HR-MAS NMR and ¹H NMR in solution, combined with chemometric analysis. The spectroscopic techniques evaluated, coupled with chemometric methods, have great potential in the investigation of complex matrices. Furthermore, several metabolites were identified by the NMR techniques.

  12. Miniature FT-IR Spectrometer For Industrial On-Line Applications

    Science.gov (United States)

    Herrala, Esko; Niemela, Pentti; Hannula, Tapio

    1989-12-01

    There have been made some attempts to transfer the advantages of FT-IR to industrial use. Commercially available research grade instruments have traditionally been large and rather expensive. However, in many potential applications only medium resolution is required, especially when measuring liquid or solid samples. This means that the mirror displacement in a Michelson interferometer remains short and computation of the Fourier transform can be executed by a small computer. Medium resolution gives also other advantages in designing a spectrometer; simple source and detector optics, less severe requirements for mirror transport, and a small size.

  13. Improved soil carbonate determination by FT-IR and X-ray analysis

    Science.gov (United States)

    Bruckman, Viktor; Wriessnig, Karin

    2013-04-01

    In forest soils on calcareous parent material, carbonate is a key component which influences both chemical and physical soil properties and thus fertility and productivity. At low organic carbon contents it is difficult to distinguish between organic and inorganic carbon (carbonate) in soils. The common gas-volumetric method to determine carbonate has a number of disadvantages. We hypothesize that a combination of two spectroscopic methods, which account for different forms of carbonate, can be used to model soil carbonate in our study region. Fourier Transform Mid-Infrared Spectroscopy (FT-MIR) was combined with X-ray diffraction (XRD) to develop a model based on partial least squares regression (PLSR). Results of the gas-volumetric Scheibler method were corrected for the calcite/dolomite ratio. The best model performance was achieved when we combined the two analytical methods using four principal components. The root mean squared error of prediction decreased from 13.07 to 11.57, while full cross-validation explained 94.5% of the variance of the carbonate content. This is the first time that a combination of the proposed methods has been used to predict carbonate in forest soils, offering a simple and cheap method to precisely estimate soil carbonate contents while increasing accuracy in comparison to spectroscopic approaches proposed earlier. This approach has the potential to complement or substitute gas-volumetric methods, specifically in study areas with low soil heterogeneity and similar parent material or in long-term monitoring by consecutive sampling. Reference: Bruckman, V. and K. Wriessnig, Improved soil carbonate determination by FT-IR and X-ray analysis. Environmental Chemistry Letters, 2012: p. 1-6. [DOI:DOI 10.1007/s10311-012-0380-4

  14. Experimental FTIR, FT-IR (gas phase), FT-Raman and NMR spectra, hyperpolarizability studies and DFT calculations of 3,5-dimethylpyrazole.

    Science.gov (United States)

    Sundaraganesan, N; Kavitha, E; Sebastian, S; Cornard, J P; Martel, M

    2009-10-15

    In the present study, structural properties of 3,5-dimethylpyrazole (3,5-DMP) have been studied extensively utilizing density functional theory (DFT) employing B3LYP exchange correlation. The Fourier transform infrared (solid phase and gas phase) and Fourier transform Raman spectra of 3,5-DMP were recorded. The Vibrational frequencies of 3,5-DMP in the ground state have been calculated by using density functional method (B3LYP) with 6-31G(d,p), 6-311G(d,p) and 6-311++G(d,p) as basis sets. Comparison of the observed fundamental vibrational frequencies of 3,5-DMP with calculated results show that 6-311++G(d,p) superior to other basis sets for molecular vibrational problems. Non linear optical NLO behavior of the examined molecule was investigated by the determination of the electric dipole moment mu, the polarizability alpha and the hyperpolarizability beta using the B3LYP/cc-pvdz method. The isotropic chemical shifts computed by (13)C and (1)H NMR analysis also show good agreement with experimental observations. The theoretically predicted FTIR and FT-Raman spectra of the title molecule have been constructed.

  15. Advanced FT-IR Gas Analysis

    Science.gov (United States)

    2005-12-01

    Qualitative vapor phase infrared spectra of straight chain hydrocarbons from a NIST website (http://webbook.nist.gov). Table 4 lists the boiling point ...that a significant fraction of the higher boiling point compounds condensed in the dryer. This may account for the ~50% concentration loss in the...hydrocarbon concentration ( THC ) between the MGA and FID. The data reprocessed was for data point #14 comparing the FID inline with MGA-1 (MG-07-126) on 11

  16. Rapid discrimination of extracts of Chinese propolis and poplar buds by FT-IR and 2D IR correlation spectroscopy

    Science.gov (United States)

    Wu, Yan-Wen; Sun, Su-Qin; Zhao, Jing; Li, Yi; Zhou, Qun

    2008-07-01

    The extract of Chinese propolis (ECP) has recently been adulterated with that of poplar buds (EPB), because most of ECP is derived from the poplar plant, and ECP and EPB have almost identical chemical compositions. It is very difficult to differentiate them by using the chromatographic methods such as high performance liquid chromatography (HPLC) and gas chromatography (GC). Therefore, how to effectively discriminate these two mixtures is a problem to be solved urgently. In this paper, a rapid method for discriminating ECP and EPB was established by the Fourier transform infrared (FT-IR) spectra combined with the two-dimensional infrared correlation (2D IR) analysis. Forty-three ECP and five EPB samples collected from different areas of China were analyzed by the FT-IR spectroscopy. All the ECP and EPB samples tested show similar IR spectral profiles. The significant differences between ECP and EPB appear in the region of 3000-2800 cm -1 of the spectra. Based on such differences, the two species were successfully classified with the soft independent modeling of class analogy (SIMCA) pattern recognition technique. Furthermore, these differences were well validated by a series of temperature-dependent dynamic FT-IR spectra and the corresponding 2D IR plots. The results indicate that the differences in these two natural products are caused by the amounts of long-chain alkyl compounds (including long-chain alkanes, long-chain alkyl esters and long chain alkyl alcohols) in them, rather than the flavonoid compounds, generally recognized as the bioactive substances of propolis. There are much more long-chain alkyl compounds in ECP than those in EPB, and the carbon atoms of the compounds in ECP remain in an order Z-shaped array, but those in EPB are disorder. It suggests that FT-IR and 2D IR spectroscopy can provide a valuable method for the rapid differentiation of similar natural products, ECP and EPB. The IR spectra could directly reflect the integrated chemical

  17. Structural Characterization of Lignins Isolated from Caragana sinica Using FT-IR and NMR Spectroscopy

    Institute of Scientific and Technical Information of China (English)

    XIAOLing-ping; SHIZheng-jun; XUFeng; SUN Run-cang; Amar Kmohanty

    2011-01-01

    In order to efficiently explore and use woody biomass,six lignin fractions were isolated from dewaxed Caragana sinica via successive extraction with organic.solvents and alkaline solutions.The lignin structures were characterized by Fourier transform infrared spectroscopy (FT-IR) and 1D and 2D Nuclear Magnetic Resonance (NMR).FT-IR spectra revealed that the “core” of the lignin structure did not significantly change during the treatment under the conditions given.The results of 1 H and 13C NMR demonstrated that the lignin fraction L2,isolated with 70% ethanol containing 1% NaOH,was mainly composed of β-O-4 ether bonds together with G and S units and trace p-hydroxyphenyl unit.Based on the 2D HSQC NMR spectrum,the ethanol organosolv lignin fraction L1,extracted with 70% ethanol,presents a predominance of β-O-4' arylether linkages (61% of total side chains),and a low abundance of condensed carbon-carbon linked structures (such as β-β',β-1',and β-5') and a lower S/G ratio.Furthermore,a small percentage (ca.9%) of the linkage side chain was found to be acylated at the γ-carbon.

  18. FT-IR Study of Carbon Nanotube Supported Co-Mo Catalysts

    Institute of Scientific and Technical Information of China (English)

    Hongyan Shang; Chenguang Liu1; Fei Wei

    2004-01-01

    In this paper, adsorption properties of dibenzothiophene (DBT) on carbon nanotube, carbon nanotube supported oxide state and sulfide state CoMo catalysts are studied by using thermal gravimetric analysis (TGA) technique and FT-IR spectroscopy. Activated carbon support, γ-Al2O3 support and supported CoMo catalysts are also subjected to studies for comparison. It was found that sulfide state CoMoS/MWCNT, CoMoS/AC and CoMoS/γ-Al2O3 catalysts adsorbed much more DBT molecules than their corresponding oxide state catalysts, as well as their corresponding supports. The chemically adsorbed DBT aromatic molecules did not undergo decomposition on the surface of supports, supported oxide state CoMo catalysts and sulfide state CoMo catalysts when out-gassing at 373 K. FT-IR results indicated that DBT molecules mainly stand upright on the active sites (acid sites and/or transition active phases) of CoMoS/MWCNT catalyst. However, DBT aromatic molecules mainly lie flat on MWCNT and CoMoO/MWCNT.

  19. The Application of FT-IR Spectroscopy for Quality Control of Flours Obtained from Polish Producers

    Science.gov (United States)

    Ceglińska, Alicja; Reder, Magdalena; Ciemniewska-Żytkiewicz, Hanna

    2017-01-01

    Samples of wheat, spelt, rye, and triticale flours produced by different Polish mills were studied by both classic chemical methods and FT-IR MIR spectroscopy. An attempt was made to statistically correlate FT-IR spectral data with reference data with regard to content of various components, for example, proteins, fats, ash, and fatty acids as well as properties such as moisture, falling number, and energetic value. This correlation resulted in calibrated and validated statistical models for versatile evaluation of unknown flour samples. The calibration data set was used to construct calibration models with use of the CSR and the PLS with the leave one-out, cross-validation techniques. The calibrated models were validated with a validation data set. The results obtained confirmed that application of statistical models based on MIR spectral data is a robust, accurate, precise, rapid, inexpensive, and convenient methodology for determination of flour characteristics, as well as for detection of content of selected flour ingredients. The obtained models' characteristics were as follows: R2 = 0.97, PRESS = 2.14; R2 = 0.96, PRESS = 0.69; R2 = 0.95, PRESS = 1.27; R2 = 0.94, PRESS = 0.76, for content of proteins, lipids, ash, and moisture level, respectively. Best results of CSR models were obtained for protein, ash, and crude fat (R2 = 0.86; 0.82; and 0.78, resp.). PMID:28243483

  20. FT-IR microspectroscopy in rapid identification of bacteria in pure and mixed culture

    Science.gov (United States)

    Fontoura, Inglid; Belo, Ricardo; Sakane, Kumiko; Cardoso, Maria Angélica Gargione; Khouri, Sônia; Uehara, Mituo; Raniero, Leandro; Martin, Airton A.

    2010-02-01

    In recent years FT-IR microspectroscopy has been developed for microbiology analysis and applied successfully in pure cultures of microorganisms to rapidly identify strains of bacteria, yeasts and fungi. The investigation and characterization of microorganism mixed cultures is also of growing importance, especially in hospitals where it is common to poly-microbial infections. In this work, the rapid identification of bacteria in pure and mixed cultures was studied. The bacteria were obtained from the Institute Oswaldo Cruz culture collection at Brazil. Escherichia coli ATCC 10799 and Staphylococcus aureus ATCC 14456 were analyzed, 3 inoculations were examined in triplicate: Escherichia coli, Staphylococcus aureus and a mixed culture of them. The inoculations were prepared according to McFarland 0.5, incubated at 37 ° C for 6 hours, diluted in saline, placed in the CaF2 window and store for one hour at 50°C to obtain thin film. The measurement was performed by Spectrum Spotlight 400 (Perkin-Elmer) equipment in the range of 4000-900 cm-1, with 32 scans using a transmittance technique with point and image modes. The data were processed (baseline, normalization, calculation of first derivate followed by smoothing with 9 point using a Savitzky-Golay algorithm) and a cluster analysis were done by Ward's algorithm and an excellent discrimination between pure and mixed culture was obtained. Our preliminary results indicate that the FT-IR microspectroscopy associated with cluster analysis can be used to discriminate between pure and mixed culture.

  1. Monitoring wine aging with Fourier transform infrared spectroscopy (FT-IR

    Directory of Open Access Journals (Sweden)

    Basalekou Marianthi

    2015-01-01

    Full Text Available Oak wood has commonly been used in wine aging but recently other wood types such as Acacia and Chestnut, have attracted the interest of the researchers due to their possible positive contribution to wine quality. However, only the use of oak and chestnut woods is approved by the International Enological Codex of the International Organisation of Vine and Wine. In this study Fourier Transform (FT-mid-infrared spectroscopy combined with Discriminant Analysis was used to differentiate wines aged in barrels made from French oak, American oak, Acacia and Chestnut and in tanks with oak chips, over a period of 12 months. Two red (Mandilaria, Kotsifali and two white (Vilana, Dafni native Greek grape varieties where used to produce four wines. The Fourier Transform Infrared (FT-IR spectra of the samples were recorded on a Zinc Selenide (ZnSe window after incubation at 40 °C for 30 min. A complete differentiation of the samples according to both the type of wood used and the contact time was achieved based on their FT-IR spectra.

  2. Development of a method for determination of fatty acid using FT-IR spectroscopy

    Directory of Open Access Journals (Sweden)

    Dimas Augusto Morozin Zaia

    2011-05-01

    Full Text Available In the present paper a new methodology has been developed for determination of fatty acids in biological systems using FT-IR spectroscopy. For this method is not necessary chromophore reagent or pre sample preparation. Palmitic acid was chosen as standard, because it is found in several biological systems. The FT-IR spectrum of palmitic acid showed two absorption bands in the region of 2852 and 2920 cm-1 attributed to CH stretching. The results for these bands showed that the Beer-Lambert Law was followed in wide range of concentration of palmitic acid (14 to 257 mmol L-1. Potassium ferricyanide (K3[Fe(CN6] was used as internal standard. Several interferents were tested and only cholesterol, ferric chloride (higher concentration, mixture of amino acids for the band at 2919 cm-1 (higher concentration and triglyceride could be interferent if they appear in high concentration. Thus, this new methodology has advantage to be not expensive and simple.

  3. FT-IR spectroscopic, thermal analysis of human urinary stones and their characterization

    Science.gov (United States)

    Selvaraju, R.; Raja, A.; Thiruppathi, G.

    2015-02-01

    In the present study, FT-IR, XRD, TGA-DTA spectral methods have been used to investigate the chemical compositions of urinary calculi. Multi-components of urinary calculi such as calcium oxalate, hydroxyl apatite, struvite and uric acid have been studied. The chemical compounds are identified by FT-IR spectroscopic technique. The mineral identification was confirmed by powder X-ray diffraction patterns as compared with JCPDS reported values. Thermal analysis techniques are considered the best techniques for the characterization and detection of endothermic and exothermic behaviors of the urinary stones. The percentages of each hydrate (COM and COD) are present together, in the presences of MAPH or UA. Finally, the present study suggests that the Urolithiasis is significant health problem in children, and is very common in some parts of the world, especially in India. So that present study is so useful and helpful to the scientific community for identification of latest human health problems and their remedies using spectroscopic techniques.

  4. New ultrarapid-scanning interferometer for FT-IR spectroscopy with microsecond time-resolution

    Science.gov (United States)

    Süss, B.; Ringleb, F.; Heberle, J.

    2016-06-01

    A novel Fourier-transform infrared (FT-IR) rapid-scan spectrometer has been developed (patent pending EP14194520.4) which yields 1000 times higher time resolution as compared to conventional rapid-scanning spectrometers. The central element to achieve faster scanning rates is based on a sonotrode whose front face represents the movable mirror of the interferometer. A prototype spectrometer with a time resolution of 13 μs was realized, capable of fully automated long-term measurements with a flow cell for liquid samples, here a photosynthetic membrane protein in solution. The performance of this novel spectrometer is demonstrated by recording the photoreaction of bacteriorhodopsin initiated by a short laser pulse that is synchronized to the data recording. The resulting data are critically compared to those obtained by step-scan spectroscopy and demonstrate the relevance of performing experiments on proteins in solution. The spectrometer allows for future investigations of fast, non-repetitive processes, whose investigation is challenging to step-scan FT-IR spectroscopy.

  5. FT-IR and XRD analysis of coal from Makum coalfield of Assam

    Indian Academy of Sciences (India)

    Binoy K Saikia; R K Boruah; P K Gogoi

    2007-12-01

    High sulphur coal sample from Ledo colliery of Makum coalfield, Assam, India was studied using FT-IR and XRD methods. FT-IR study shows the presence of aliphatic –CH, –CH2 and –CH3 groups, aliphatic C–O–C stretching associated with –OH and –NH stretching vibrations and HCC rocking (single and condensed rings). XRD pattern of the coal shows that it is amorphous in nature. Function of Radial Distribution Analysis (FRDA) indicates that coal is lignite in type and there is no evidence of graphite-like structure. The first maximum in the G() plot of FRDA at = 0.14 nm relates to the aliphatic C–C bond (Type C–CH=CH–C), the second maximum at = 0.25 nm relates to the distance between carbon atoms of aliphatic chains that are located across one carbon atom. The curve intensity profiles obtained from FRDA show quite regular molecular packets for this coal. The coal was found to be lignite in nature.

  6. Cyclohexene Photo-oxidation over Vanadia Catalyst Analyzed by Time Resolved ATR-FT-IR Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Frei, Heinz; Mul, Guido; Wasylenko, Walter; Hamdy, M. Sameh; Frei, Heinz

    2008-06-04

    Vanadia was incorporated in the 3-dimensional mesoporous material TUD-1 with a loading of 2percent w/w vanadia. The performance in the selective photo-oxidation of liquid cyclohexene was investigated using ATR-FT-IR spectroscopy. Under continuous illumination at 458 nm a significant amount of product, i.e. cyclohexenone, was identified. This demonstrates for the first time that hydroxylated vanadia centers in mesoporous materials can be activated by visible light to induce oxidation reactions. Using the rapid scan method, a strong perturbation of the vanadyl environment could be observed in the selective oxidation process induced by a 458 nm laser pulse of 480 ms duration. This is proposed to be caused by interaction of the catalytic centre with a cyclohexenyl hydroperoxide intermediate. The restoration of the vanadyl environment could be kinetically correlated to the rate of formation of cyclohexenone, and is explained by molecular rearrangement and dissociation of the peroxide to ketone and water. The ketone diffuses away from the active center and ATR infrared probing zone, resulting in a decreasing ketone signal on the tens of seconds time scale after initiation of the photoreaction. This study demonstrates the high potential of time resolved ATR FT-IR spectroscopy for mechanistic studies of liquid phase reactions by monitoring not only intermediates and products, but by correlating the temporal behavior of these species to molecular changes of the vanadyl catalytic site.

  7. In situ FT-IR microscopic study on enzymatic treatment of poplar wood cross-sections.

    Science.gov (United States)

    Gierlinger, Notburga; Goswami, Luna; Schmidt, Martin; Burgert, Ingo; Coutand, Catherine; Rogge, Tilmann; Schwanninger, Manfred

    2008-08-01

    The feasibility of Fourier transform infrared (FT-IR) microscopy to monitor in situ the enzymatic degradation of wood was investigated. Cross-sections of poplar wood were treated with cellulase Onozuka RS within a custom-built fluidic cell. Light-optical micrographs and FT-IR spectra were acquired in situ from normal and tension wood fibers. Light-optical micrographs showed almost complete removal of the gelatinous (G) layer in tension wood. No structural and spectral changes were observed in the lignified cell walls. The accessibility of cellulose within the lignified cell wall was found to be the main limiting factor, whereas the depletion of the enzyme due to lignin adsorption could be ruled out. The fast, selective hydrolysis of the crystalline cellulose in the G-layer, even at room temperature, might be explained by the gel-like structure and the highly porous surface. Young plantation grown hardwood trees with a high proportion of G-fibers thus represent an interesting resource for bioconversion to fermentable sugars in the process to bioethanol.

  8. Application of FT-IR spectroscopy to assess physiological stress in rugby players during fatigue test

    Directory of Open Access Journals (Sweden)

    Paulo Cesar Caetano Júnior

    Full Text Available AbstractIntroduction: The diagnosis based on salivary biomarkers provides information about the physiological condition. However, the clinical trials used to analyze these biomarkers are relatively expensive and laborious. Thus, the purpose of this study was to identify the physiological stress in players using Fourier transform infrared spectroscopy (FT-IR. Methods Thirteen male rugby players were submitted to the treadmill fatigue test and saliva collections were performed before and immediately after test. The FT-IR spectra of saliva samples were analyzed by the second derivative and cluster analysis. Results From the results of cluster analysis were possible to discriminate the spectra of saliva before and after physical effort using the spectral region between 1490 to 1420 cm–1. Only the saliva spectra from two players were not discriminated in pre-exercise group and post-exercise group, which are in agreement with lowest value of heart rates. Conclusion The second derivative showed differences between the average spectra of saliva samples collected pre and post-test, which explain the spectra discrimination by the cluster analysis using a specific infrared region for the identification of physiological stress.

  9. Raman microspectrometry, FT-IR and inclusion characteristics of gem garnets from Tanzania and Madagascar

    Institute of Scientific and Technical Information of China (English)

    Sang-kon Kim; Maeng-eon Park; Seung-gyun Baek; Kyu-youl Sung; Sun-ok Kim; Hee-yul Park

    2004-01-01

    Chemical composition, Raman microspectrometry, and Fourier transform infrared (FT-IR) and SEM-CL (Cathodluminescence) analyses are carried out for Tanzania and Madagascar garnets for locality identification. Inclusion study was sustained after electron probe microanalysis (EPMA). Needle-like illmenites, apatites and zircons were the most common solid inclusions in Tanzania garnets. Madagascar garnets revealed rutile needles and apatites were also observed, but differences in size, shape and distribution patterns were noticed compared to Tanzania garnets. Tanzania garnets exhibited all types of observable fluid inclusions such as "fingerprint" pattern, called Type Ⅰ-A, liquid-only (L) single phase fluid inclusion, called Type Ⅰ-B and Type Ⅱ-A (L + S), Type Ⅱ-B (L + V) and Type Ⅲ-A (L + Sylvite +S), Type Ⅲ-B (L+S+V), while no more than two phase fluid inclusions found in both Madagascar and Korea garnets even if all examined garnets from three localities retained "fingerprint" features, so called, partially healed fractures, in common. Chemical composition, Raman microspectrometry and Fourier transform infrared (FT-IR) analysis taken turned out to be useful methods for the purpose of this study. Using consequences of SEM-CL and inclusion study, accordingly,the locality identification of gem-quality garnets is capable of being available in further application for other kinds of gemstones.

  10. FT-IR spectroscopy combined with DFT calculation to explore solvent effects of vinyl acetate.

    Science.gov (United States)

    Chen, Yi; Zhang, Hui; Liu, Qing

    2014-05-21

    The infrared vibration frequencies of vinyl acetate (VAc) in 18 different solvents were theoretically computed at Density Function Theory (DFT) B3LYP/6-311G(*) level based on Polarizable Continuum Model (PCM) and experimentally recorded by FT-IR spectroscopy. The solvent-induced long-range bulk electrostatic solvation free energies of VAc (ΔGelec) were calculated by the SMD model. The C=O stretching vibration frequencies of VAc were utilized as a measure of the chemical reactivities of the CC group in VAc. The calculated and experimental C=O stretching vibration frequencies of VAc (νcal(C=O) and νexp(C=O)) were correlated with empirical solvent parameters including the KBM equation, the Swain equation and the linear solvation energy relationships (LSER). Through ab initio calculation, assignments of the two C=O absorption bands of VAc in alcohol solvents were achieved. The PCM, SMD and ab initio calculation offered supporting evidence to explain the FT-IR experimental observations from differing aspects.

  11. FT-IR and XRD analysis of coal from Makum coalfield of Assam

    Energy Technology Data Exchange (ETDEWEB)

    Saikia, B.K.; Boruah, R.K.; Gogoi, P.K. [Tezpur University, Tezpur (India). Dept. of Chemical Science

    2007-12-15

    High sulphur coal sample from Ledo colliery of Makum coalfield, Assam, India was studied using FT-IR and XRD methods. FT-IR study shows the presence of aliphatic -CH, -CH{sub 2} and -CH{sub 3} groups, aliphatic C-O-C stretching associated with -OH and -NH stretching vibrations and HCC rocking (single and condensed rings). XRD pattern of the coal shows that it is amorphous in nature. Function of Radial Distribution Analysis (FRDA) indicates that coal is lignite in type and there is no evidence of graphite-like structure. The first maximum in the G(r) plot of FRDA at r = 0.14 nm relates to the aliphatic C-C bond (Type C-CH = CH-C), the second maximum at r = 0.25 nm relates to the distance between carbon atoms of aliphatic chains that are located across one carbon atom. The curve intensity profiles obtained from FRDA show quite regular molecular packets for this coal. The coal was found to be lignite in nature.

  12. XRD and FT-IR investigations of sub-bituminous Assam coals

    Energy Technology Data Exchange (ETDEWEB)

    Saikia, B.K.; Boruah, R.K.; Gogoi, P.K. [Tezpur University, Tezpur (India). Dept. of Chemical Science

    2007-08-15

    Two coal samples collected from Makum coal field, Assam, India were studied by XRD and FT-IR techniques. The X-ray diffractogram shows the existence of some crystalline carbons in Assam coals as proven by the appearance of peaks. The radial distribution functional (RDF) method was applied for the determination of structural aspects of the coals. The study indicates that the coals are lignite in type and there is no evidence of graphite-like structures. The maximum in the Gr) plots of function of radial distribution of atoms (FRDA) relates to different distances between carbon atoms of aliphatic chains. The first significant maximum relates to the C-C bond (type C-CH=CH-C), the second maximum relates to the distance between carbon atoms of aliphatic chains that are located across one carbon atom. The curve intensity profiles obtained from FRDA show quite regular molecular packets for this coal. The coals were found to be lignite in nature. FT-IR study shows the presence of aliphatic carbon, C=O and C-O stretching associated with -OH and -NH stretching vibrations. Kaolinite and quartz were also found to be major minerals in Assam coals by FTIR spectroscopy. The difference in intensities of carbonyl groups of the coal samples is likely to relate with the rank.

  13. Recognition of FT-IR Data Cuscutae Semen, Japanese Dodder, and Sinapis Semen Using Discrete Wavelet Transformation and RBF Networks

    Directory of Open Access Journals (Sweden)

    Tao Hu

    2013-01-01

    Full Text Available Horizontal attenuation total reflection Fourier transformation infrared spectroscopy (HATR-FT-IR studies on cuscutae semen and its confusable varieties Japanese dodder and sinapis semen combined with discrete wavelet transformation (DWT and radial basis function (RBF neural networks have been conducted in order to classify them. DWT is used to decompose the FT-IRs of cuscutae semen, Japanese dodder, and sinapis semen. Two main scales are selected as the feature extracting space in the DWT domain. According to the distribution of cuscutae semen, Japanese dodder, and sinapis semen’s FT-IRs, three feature regions are determined at detail 3, and two feature regions are determined at detail 4 by selecting two scales in the DWT domain. Thus five feature parameters form the feature vector. The feature vector is input to the RBF neural networks to train so as to accurately classify the cuscutae semen, Japanese dodder, and sinapis semen. 120 sets of FT-IR data are used to train and test the proposed method, where 60 sets of data are used to train samples, and another 60 sets of FT-IR data are used to test samples. Experimental results show that the accurate recognition rate of cuscutae semen, Japanese dodder, and sinapis semen is average of 100.00%, 98.33%, and 100.00%, respectively, following the proposed method.

  14. Identification and classification of textile fibres using ATR-FT-IR spectroscopy with chemometric methods.

    Science.gov (United States)

    Peets, Pilleriin; Leito, Ivo; Pelt, Jaan; Vahur, Signe

    2017-02-15

    The possibility of classification of single- and two-component textile materials using ATR-FT-IR spectra and chemometric methods, principal component analysis (PCA) and discriminant analysis, was assessed. Altogether 89 textile samples belonging to 26 different types (11 one- and 15 two-component textiles) were investigated. It was found that PCA classification using only two or three principal components (PCs) enables identifying different one- and two-component textiles, although with two important limitations: it was not always possible to distinguish between the cellulose-based fibres (cotton, linen and in some cases viscose) and it was only partly possible to distinguish between silk and wool. The statistical discriminant analysis can use as many PCs as there are sample classes and due to that can discriminate between single-component fibres, including viscose from linen and cotton as well as silk from wool. Besides that, in both of these cases, involving optical microscopy as an additional technique enabled unequivocal identification of the fibres. The possibilities of semi-quantitative analysis of mixed fibres (cotton-polyester, wool-polyester and wool-polyamide) with PCA were investigated and it was found that approximate quantitative composition is obtainable if for the mixed fibre sample a number of spectra are averaged in order to minimize the effect of structural inhomogeneity. For approximate content determination 25 spectra of selected two-component samples were registered for calibration and the averaged spectrum for each sample was computed. Due to the structural inhomogeneity of mixed textiles, obtaining accurate quantitative composition from real samples is not possible with ATR-FT-IR. The main problems with ATR-FT-IR-PCA classification are (1) difficulties in getting high quality spectra from some textiles (e.g. polyacrylic), (2) inhomogeneity of the textile fibres in the case of two-component fibres and (3) intrinsic similarity between the

  15. Identification and classification of textile fibres using ATR-FT-IR spectroscopy with chemometric methods

    Science.gov (United States)

    Peets, Pilleriin; Leito, Ivo; Pelt, Jaan; Vahur, Signe

    2017-02-01

    The possibility of classification of single- and two-component textile materials using ATR-FT-IR spectra and chemometric methods, principal component analysis (PCA) and discriminant analysis, was assessed. Altogether 89 textile samples belonging to 26 different types (11 one- and 15 two-component textiles) were investigated. It was found that PCA classification using only two or three principal components (PCs) enables identifying different one- and two-component textiles, although with two important limitations: it was not always possible to distinguish between the cellulose-based fibres (cotton, linen and in some cases viscose) and it was only partly possible to distinguish between silk and wool. The statistical discriminant analysis can use as many PCs as there are sample classes and due to that can discriminate between single-component fibres, including viscose from linen and cotton as well as silk from wool. Besides that, in both of these cases, involving optical microscopy as an additional technique enabled unequivocal identification of the fibres. The possibilities of semi-quantitative analysis of mixed fibres (cotton-polyester, wool-polyester and wool-polyamide) with PCA were investigated and it was found that approximate quantitative composition is obtainable if for the mixed fibre sample a number of spectra are averaged in order to minimize the effect of structural inhomogeneity. For approximate content determination 25 spectra of selected two-component samples were registered for calibration and the averaged spectrum for each sample was computed. Due to the structural inhomogeneity of mixed textiles, obtaining accurate quantitative composition from real samples is not possible with ATR-FT-IR. The main problems with ATR-FT-IR-PCA classification are (1) difficulties in getting high quality spectra from some textiles (e.g. polyacrylic), (2) inhomogeneity of the textile fibres in the case of two-component fibres and (3) intrinsic similarity between the

  16. Micro-Attenuated Total Reflection Fourier Transform Infrared (Micro ATR FT-IR) Spectroscopic Imaging with Variable Angles of Incidence.

    Science.gov (United States)

    Wrobel, Tomasz P; Vichi, Alessandra; Baranska, Malgorzata; Kazarian, Sergei G

    2015-10-01

    The control of the angle of incidence in attenuated total reflection (ATR) Fourier transform infrared (FT-IR) spectroscopy allows for the probing of the sample at different depths of penetration of the evanescent wave. This approach has been recently coupled with macro-imaging capability using a diamond ATR accessory. In this paper, the design of optical apertures for the micro-germanium (Ge) ATR objective is presented for an FT-IR spectroscopic imaging microscope, allowing measurements with different angles of incidence. This approach provides the possibility of three-dimensional (3D) profiling in micro-ATR FT-IR imaging mode. The proof of principle results for measurements of polymer laminate samples at different angles of incidence confirm that controlling the depth of penetration is possible using a Ge ATR objective with added apertures.

  17. FT-IR spectroscopy and DFT calculation study on the solvent effects of benzaldehyde in organic solvents.

    Science.gov (United States)

    Li, Yi; Zhang, Hui; Liu, Qing

    2012-02-01

    FT-IR spectra of benzaldehyde in 11 different organic solvents were recorded and analyzed. The density functional theory (DFT) B3LYP/6-31G* method was chosen to calculate the infrared spectrum of benzaldehyde in gaseous state. The electrostatic effects of different solvents in benzaldehyde solutions were calculated using DFT with the self-consistent isodensity polarizable continuum model (SCI-PCM). Two remarkable carbonyl (C=O) peaks of benzaldehyde were observed by FT-IR in alcohol solvents, which were caused by different hydrogen bond species and explained by ab initio calculation. The results showed that the combination of SCI-PCM model and ab initio calculation could give excellent agreements with FT-IR spectra of title compound in solutions.

  18. Crystallization and micro FT-IR spectroscopy investigation of cytochrome bc1 complex

    Institute of Scientific and Technical Information of China (English)

    岳文海; 何季平; 谢荣; 徐建兴; 朱克莉; 翁诗甫

    1996-01-01

    A simple method to obtain large red crystals of cytochrome bc1 complex from beef heart mitochondria has been developed. These crystals are very stable. Their shapes are retained for a long time in tip-sealed Pasteur pipets placed in a refrigerator. The structure of crystalline cytochrome bc1 complex by micro FT-IR spectroscopy has been investigated. Based on the IR spectra of cytochrome c, the empirical assignments of the major infrared frequencies of cytochrome bc1 complex are given. Infrared frequencies and relative intensities of variable orientation and section of crystal are significantly different. These imply that infrared spectral characterization of the membrane protein crystallization is associated with the variable symmetries and orientations of the structure. Experimental results show that phospholipid exists in the crystal of cytochrome bc1 complex. The membrane protein is probably spanned on the mitochondrial membrane and buried in phospholipid bilayer in an asymmetric manner.

  19. [FT-IR spectroscopic analysis in monitoring of hydroxyl stretching vibrations in plant hydrogels].

    Science.gov (United States)

    Pielesz, Anna; Biniaś, Dorota; Wieczorek, Joanna

    2011-01-01

    In recent years, some bioactive hydrogels isolated from natural sources have attracted much attention in the field of biochemistry and pharmacology. This article attempts to review the current structural and conformational characterization of some importantly bioactive hydrogels isolated from following plant: Symphytum officinale, Thymus pulegioides, Trigonella foenum-graecum L., Tussilago farfara L., Hyssopus officinalis, Althaea officinalis L., Equisetum arvense L. Linum usitatissimum L. and Fucus vesiculosus L. Hydrogels are cross-linked three-dimensional polysaccharide macromolecular networks that contain a large fraction of water within their structure. FT-IR spectroscopic analysis showed a strong band at 3500-3100 cm(-1) attributed to hydroxyl (the intermolecular and the intramolecular hydrogen bonds) stretching vibrations changes.

  20. Molecular structure and spectral (FT-IR, Raman) investigations of 3-aminocoumarin

    Science.gov (United States)

    Dereli, Ömer

    2016-05-01

    The molecular structure of 3-Aminocoumarin was determined by conformational analysis. Conformational space was scanned by conformer distribution option of Spartan 08 program package using Merck Molecular Force Field (MMFF) method. Then obtained conformers were optimized by B3LYP/6-311++ G( d, p) and B3LYP/6-311 G( d, p) levels of Density Functional Theory. As a result of these calculations, only one conformer was determined. Vibrational frequencies of this conformer were calculated by Gaussian 03 program package using the same levels of geometry optimizations. The FT-IR and Raman spectra of 3-Aminocoumarin were recorded and compared with the calculated values. Consequently, a good agreement between experimental and the calculated values were founded. Molecular electrostatic potentials (MEPs), HOMO-LUMO energies, thermodynamic properties and Mulliken atomic charges were also covered in this study.

  1. Adsorption and interaction of 5-fluorouracil with montmorillonite and saponite by FT-IR spectroscopy

    Science.gov (United States)

    Akalin, Elif; Akyuz, Sevim; Akyuz, Tanil

    2007-05-01

    Adsorption of 5-fluorouracil (5-FU) on montmorillonite and saponite has been investigated using FT-IR spectrometry. The intercalation of 5-FU within montmorillonite or saponite has been shown by X-ray diffraction to increase the interlayer spacing. In order to investigate interaction of 5-FU with clays, the harmonic and anharmonic vibrational wavenumbers of free 5-FU and 5-FU interacting with Al(OH) 3 have been calculated at the DFT/B3LYP level with 6-31++G(d,p) basis set by using Gaussian 03 program set. The solution effect on 5-FU was also calculated by using polarizable continuum model (PCM). Experimental and calculated results indicated that 5-FU interacted with clays by direct or indirect coordination (through water molecules) to the Lewis acidic centers.

  2. Measurement of single moving particle temperatures with an FT-IR spectrometer

    DEFF Research Database (Denmark)

    Clausen, Sønnik; Sørensen, L.H.

    1996-01-01

    A conventional scanning FT-IR spectrometer is used to measure the blackbody radiation through a rapidly moving pinhole in an experiment simulating a dying hot particle. The effects and errors from source movements are analyzed and verified through experiments. The importance of the scanning...... velocity, phase-correction method, and temperature variations during scanning is investigated. It is shown that a calibration of the system at one temperature is sufficient for accurate spectral radiance and temperature measurements throughout a broad temperature range. The temperature errors are reduced...... by a factor of 2-10 compared with results from a typical two-color pyrometer. A novel method is presented for measuring emission spectra from single moving particles passing the field of view of the spectrometer in a random manner....

  3. FT-IR microscopical analysis with synchrotron radiation: The microscope optics and system performance

    Energy Technology Data Exchange (ETDEWEB)

    Reffner, J.A.; Martoglio, P.A. [Spectra-Tech, Inc., Shelton, CT (United States); Williams, G.P. [Brookhaven National Lab., Upton, NY (United States)

    1995-01-01

    When a Fourier transform infrared (FT-IR) microspectrometer was first interfaced with the National Synchrotron Light Source (NSLS) in September 1993, there was an instant realization that the performance at the diffraction limit had increased 40-100 times. The synchrotron source transformed the IR microspectrometer into a true IR microprobe, providing high-quality IR spectra for probe diameters at the diffraction limit. The combination of IR microspectroscopy and synchrotron radiation provides a powerful new tool for molecular spectroscopy. The ability to perform IR microspectroscopy with synchrotron radiation is still under development at Brookhaven National Laboratory, but several initial studies have been completed that demonstrate the broad-ranging applications of this technology and its potential for materials characterization.

  4. Multivariate chemometric approach to thermal solid-state FT-IR monitoring of pharmaceutical drug compound.

    Science.gov (United States)

    Tan, Wei Jian; Widjaja, Effendi

    2008-08-01

    The study of thermal-related solid-state reaction monitored by spectroscopic method needs the use of advanced multivariate chemometric approach. It is because visual inspection of spectral data on particular functional groups or spectral bands is difficult to reveal the complete physical and chemical information. The spectral contributions from various species involved in the solid-state changes are generally highly overlapping and the spectral differences between reactant and product are usually quite minute. In this article, we demonstrate the use of multivariate chemometric approach to resolve the in situ thermal-dependent Fourier-transform infrared (FT-IR) mixture spectra of lisinopril dihydrate when it was heated from 24 to 170 degrees C. The collected FT-IR mixture spectra were first subjected to singular value decomposition (SVD) to obtain the right singular vectors. The right singular vectors were rotated into a set of pure component spectral estimates based on entropy minimization and spectral dissimilarity objective functions. The resulting pure component spectral estimates were then further refined using alternating least squares (ALS). In current study, four pure component spectra, that is, lisinopril dihydrate, monohydrate, anhydrate, and diketopiperazine (DKP) were all resolved and the relative thermal-dependent contributions of each component were also obtained. These relative contributions revealed the critical temperature for each transformation and degradation. This novel approach provides better interpretation of the pathway of dehydration and intramolecular cyclization of lisinopril dihydrate in the solid state. In addition, it can be used to complement the information obtained from differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA).

  5. Analysis of quartz by FT-IR in air samples of construction dust.

    Science.gov (United States)

    Virji, M Abbas; Bello, Dhimiter; Woskie, Susan R; Liu, X Michael; Kalil, Andrew J

    2002-03-01

    The construction industry is reported to have some of the highest exposures to silica-containing dust. With the designation of crystalline silica as a group I human carcinogen by the International Agency for Research on Cancer (IARC), there exists a need for an analytical method to accurately quantify low levels of quartz. A method is described that uses FT-IR for quartz analysis of personal air samples collected from heavy and highway construction sites using 4-stage personal impactors. Sample filters were ashed and 13-mm or 5-mm pellets were prepared. Absorbance spectra were collected using FT-IR at resolution of 1 cm(-1) and 64 scans per spectrum. Two spectra were collected per sample using the appropriate background spectrum subtraction. Spectral manipulations such as Fourier self-deconvolution and derivatizations were performed to improve quantification. Peak height for quartz was measured at 798 cm(-1) for quantitative analysis. The estimated limit of detection for the 5-mm pellets was 1.3 microg. Recoveries of Min-U-Sil 5 spikes showed an average of > or = 94 percent for the two pellet types. The coefficient of variation of the 5-mm pellet was 9 percent at 6 microg quartz load, and 7 percent at 62 microg load. Interferences from clay, amorphous silica, concrete, calcite, and kaolinite were investigated, these being the more likely sources of interferences in construction environment. Spikes of mixtures of amorphous silica or kaolinite with Min-U-Sil 5 showed both contaminants introduced, on average, a positive error of clay or concrete with Min-U-Sil 5 showed overall average recovery of 100 percent and 90 percent, respectively, after accounting for the presence of quartz in clay and concrete. This method can quantify low levels of quartz with reasonable accuracy in the face of common contaminants found in the construction industry.

  6. Characterization of Paracoccidioides brasiliensis by FT-IR spectroscopy and nanotechnology.

    Science.gov (United States)

    Ferreira, Isabelle; Ferreira-Strixino, Juliana; Castilho, Maiara L; Campos, Claudia B L; Tellez, Claudio; Raniero, Leandro

    2016-01-01

    Paracoccidioides brasiliensis, the etiological agent of paracoccidioidomycosis, is a dimorphic fungus existing as mycelia in the environment (or at 25°C in vitro) and as yeast cells in the human host (or at 37°C in vitro). Because mycological examination of lesions in patients frequently is unable to show the presence of the fungus and serological tests can misdiagnose the disease with other mycosis, the development of new approach's for molecular identification of P. brasiliensis spurges is needed. This study describes the use of a gold nanoprobe of a known gene sequence of P. brasiliensis as a molecular tool to identify P. brasiliensis by regular polymerase chain reaction (PCR) associated with a colorimetric methods. This approach is suitable for testing in remote areas because it does not require any further step than gene amplification, being safer and cheaper than electrophoresis methods. The proposed test showed a color change of the PCR reaction mixture from red to blue in negative samples, whereas the solution remains red in positive samples. We also performed a Fourier Transform Infrared (FT-IR) Spectroscopy analysis to characterize and compare the chemical composition between yeast and mycelia forms, which revealed biochemical differences between these two forms. The analysis of the spectra showed that differences were distributed in chemical bonds of proteins, lipids and carbohydrates. The most prominent difference between both forms was vibration modes related to 1,3-β-glucan usually found in mycelia and 1,3-α-glucan found in yeasts and also chitin forms. In this work, we introduce FT-IR as a new method suitable to reveal overall differences that biochemically distinguish each form of P. brasiliensis that could be additionally used to discriminate biochemical differences among a single form under distinct environmental conditions.

  7. Characterization of supersaturated lidocaine/polyacrylate pressure sensitive adhesive systems: thermal analysis and FT-IR.

    Science.gov (United States)

    Cui, Yong; Frank, Sylvan G

    2006-03-01

    Supersaturated and crystallized lidocaine (LC)/pressure sensitive adhesive (PSA) systems have been studied by differential scanning calorimetry (DSC) and FT-IR with the objective of characterizing the thermodynamic states and compatibility of the two-component systems. Analysis of the phase behavior of LC/DT2287 systems indicates that LC and DT2287 are thermodynamically miscible within the composition range containing less than approximately 20% w/w LC, beyond which LC may crystallize from the blends forming a separated crystalline phase. The composition dependence of the glass transition temperature (T(g)) was used to characterize the physical and thermodynamic states of the supersaturated systems. The Fox, Gordon-Taylor, Kwei, Kovacs, and Brekner, Schneider and Cantow (BSC) equations were employed to conduct the analysis. It was found that the PSA in the supersaturated LC/PSA systems underwent significant entropic relaxation upon mixing. LC in the miscible systems is absorbed into and swells the polymer network of the PSA, thereby exhibiting reduced molecular mobility, while the PSA attains significant molecular conformation relaxation and entropy increase. It was also found that LC molecules extensively participate in molecular relaxation of the PSA throughout the composition range studied. The molecular mobility of LC is inhibited as the volume fraction of DT2287 increases, suggesting that the PSA molecular network reduces the molecular mobility of LC by closely involving LC molecules in its relaxation, and thereby may enhancing the physical stability of the systems. No strong intermolecular interactions between the two components were found based upon the results of T(g)-composition analysis, and was confirmed by FT-IR studies. This indicates that the analysis based on the BSC equation provides more precise characterization of polymer systems than the T(g) -composition analysis based on other equations cited. Copyright 2006 Wiley-Liss, Inc. and the American

  8. Effect of Water on HEMA Conversion by FT-IR Spectroscopy

    Directory of Open Access Journals (Sweden)

    TS. Jafarzadeh Kashi

    2007-09-01

    Full Text Available Objective: The use of HEMA as a biocompatible material in dentin bonding systems and its potential for clinical applications has been well established. Excess water can affect conversion of bonding resins. The aim of this study was to survey the effect of water on the degree of conversion of HEMA by Fourier Transform Infra-red Spectroscopy (FT-IR.Materials and Methods: In this experimental study, distilled water was added in amounts of 0, 0.05, 0.1, 0.2, and 0.4 ml to 1 ml of curable HEMA solution. Six repetitions per wa-ter ratio were made and investigated. Each sample was polymerized for 60 seconds. De-gree of conversion was obtained from the absorbance IR-Spectrum of the materials before and after polymerization by FT-IR spectroscopy. One way ANOVA and Tukey-HSD were carried out to compare and detect any differences among groups.Results: Statistical analysis indicates highly significant difference between pairs of groups at level (P<0.001. The results showed a trend of decreasing in HEMA conversion with increasing water. Degree of conversion changes significantly within the 0.05 ml to 0.2 ml water range. However, degree of conversion did not change after reaching 0.02 ml and before 0.05.Conclusion: Degree of conversion of HEMA decreased by increasing water. The most dramatic effect of water on the polymerization process occurs within a range which exists under clinical conditions. The reason that the degree of conversion did not show signifi-cant result before 0.05 ml may be related to the hydrophilic nature of HEMA.

  9. FT-IR spectroscopic, AM1 and PM3 computational studies of conformation of natural products: cytisine.

    Science.gov (United States)

    Górnicka, Elzbieta; Raczyńska, Ewa D

    2002-06-10

    Infrared spectra were recorded for cytisine (1) and its model compounds: N-methyl-2-pyridone (2) and piperidine (3) in solution. Eight solvents of different polarity, polarizability and acid-base properties: CCl(4), CS(2), CHCl(3), CDCl(3) (for comparison with the NMR spectra), CH(2)Cl(2), MeOH, Et(2)O and Et(3)N were chosen. Experimental FT-IR spectra were analysed with the help of those calculated for isolated derivatives at the AM1 and PM3 levels. Influence of environment on the conformational preferences in solvated cytisine was discussed and compared with those in the solid state (X-ray measurements) and in the gas phase (quantum-mechanical calculations).

  10. Evaluation of Turmeric Powder Adulterated with Metanil Yellow Using FT-Raman and FT-IR Spectroscopy

    Directory of Open Access Journals (Sweden)

    Sagar Dhakal

    2016-05-01

    Full Text Available Turmeric powder (Curcuma longa L. is valued both for its medicinal properties and for its popular culinary use, such as being a component in curry powder. Due to its high demand in international trade, turmeric powder has been subject to economically driven, hazardous chemical adulteration. This study utilized Fourier Transform-Raman (FT-Raman and Fourier Transform-Infra Red (FT-IR spectroscopy as separate but complementary methods for detecting metanil yellow adulteration of turmeric powder. Sample mixtures of turmeric powder and metanil yellow were prepared at concentrations of 30%, 25%, 20%, 15%, 10%, 5%, 1%, and 0.01% (w/w. FT-Raman and FT-IR spectra were acquired for these mixture samples as well as for pure samples of turmeric powder and metanil yellow. Spectral analysis showed that the FT-IR method in this study could detect the metanil yellow at the 5% concentration, while the FT-Raman method appeared to be more sensitive and could detect the metanil yellow at the 1% concentration. Relationships between metanil yellow spectral peak intensities and metanil yellow concentration were established using representative peaks at FT-Raman 1406 cm−1 and FT-IR 1140 cm−1 with correlation coefficients of 0.93 and 0.95, respectively.

  11. Sugar and acid content of Citrus prediction modeling using FT-IR fingerprinting in combination with multivariate statistical analysis.

    Science.gov (United States)

    Song, Seung Yeob; Lee, Young Koung; Kim, In-Jung

    2016-01-01

    A high-throughput screening system for Citrus lines were established with higher sugar and acid contents using Fourier transform infrared (FT-IR) spectroscopy in combination with multivariate analysis. FT-IR spectra confirmed typical spectral differences between the frequency regions of 950-1100 cm(-1), 1300-1500 cm(-1), and 1500-1700 cm(-1). Principal component analysis (PCA) and subsequent partial least square-discriminant analysis (PLS-DA) were able to discriminate five Citrus lines into three separate clusters corresponding to their taxonomic relationships. The quantitative predictive modeling of sugar and acid contents from Citrus fruits was established using partial least square regression algorithms from FT-IR spectra. The regression coefficients (R(2)) between predicted values and estimated sugar and acid content values were 0.99. These results demonstrate that by using FT-IR spectra and applying quantitative prediction modeling to Citrus sugar and acid contents, excellent Citrus lines can be early detected with greater accuracy.

  12. Detection and classification of salmonella serotypes using spectral signatures collected by fourier transform infrared (FT-IR) spectroscopy

    Science.gov (United States)

    Spectral signatures of Salmonella serotypes namely Salmonella Typhimurium, Salmonella Enteritidis, Salmonella Infantis, Salmonella Heidelberg and Salmonella Kentucky were collected using Fourier transform infrared spectroscopy (FT-IR). About 5-10 µL of Salmonella suspensions with concentrations of 1...

  13. Simultaneous determination of some artificial sweeteners in ternary formulations by FT-IR and EI-MS

    Science.gov (United States)

    Tosa, Nicoleta; Moldovan, Zaharie; Bratu, Ioan

    2012-02-01

    Artificial sweeteners are widely used in food, beverage and pharmaceutical industries all over the world. In this study some non-nutritive sweeteners such as aspartame, acesulfame-K, sodium cyclamate and sodium saccharin were simultaneously determined in ternary mixtures using FT-IR and EI-MS measurements. FT-IR method is based on direct measurements of the peak height values and area centered on 1736 cm-1, 836 cm-1, 2854 cm-1 and 1050 cm-1 for aspartame, acesulfame-K, sodium cyclamate and sodium saccharin, respectively. Mass spectrometry determinations show the characteristic peaks at m/z 91 and 262 for aspartame,m/z 43 and 163 acesulfame-K,m/z 83 and 97 for sodium cyclamate andm/z 104 and 183 for sodium saccharin. The results obtained by EI-MS in different formulations are in agreement with the FT-IR ones and provide also essential data concerning the purity grade of the components. It is concluded that FT-IR and EI-MS procedures developed in this work represent a fast, sensitive and low cost alternative in the quality control of such sweeteners in different ternary formulations.

  14. Discrimination of different processed animal proteins (PAPs by FT-IR spectroscopy based on their fat characteristics

    Directory of Open Access Journals (Sweden)

    Pu, Q.

    2014-01-01

    Full Text Available This study was undertaken to explore the potential of FT-IR technique for discriminating different species of processed animal proteins (PAPs based on their fat characteristics. A total of 47 source-reliable PAPs samples containing fish meal, porcine, bovine, ovine and poultry meat and bone meal (MBM were involved in the present study. The results obtained showed that the FT-IR differentiated quite well between the fat derived from different species of PAPs, especially at the bands of 3,006 cm-1 and 722 cm-1. Results provided evidence that FT-IR differentiated the fat derived from fish meal, terrestrial non-ruminant and ruminant MBM quite well. Fish meal and ruminant MBM samples could be discriminated effectively by both the sensitivity and specificity values which were 1.00 and 1.00, respectively. For non-ruminant MBM samples, the sensitivity and specificity were 1.00 and 0.96, respectively. However, it was hard to distinguish bovine MBM from ovine ones as well as porcine MBM from poultry ones. The result makes it possible to allow FT-IR analytical methodology as a preliminary study for the exploitation of a rapid and reliable way for the identification of the animal origin of PAPs used in feeding stuffs.

  15. FT-IR Characterization of Pollen Biochemistry, Viability, and Germination Capacity in Saintpaulia H. Wendl. Genotypes

    Directory of Open Access Journals (Sweden)

    Erzsebet Buta

    2015-01-01

    Full Text Available FT-IR characterization of pollen biochemistry was analyzed to detect possible connection with the viability (by staining with potassium iodide, 25% and the germination capacity (on solid nutrient medium, in 15 Saintpaulia genotypes. Vibrational spectroscopy indicates that the pollen of S. ionantha genotype “Red Velvet” is rich in proteins, lipids, triglycerides, and esters and has a viability of 88.4% and a low germination capacity (27.16%. For S. ionantha “Jolly Red” and “Lucky Ladybug” genotypes, pollen showed high viability (88.81–91.49% and low germination capacity (23.02–9.17%, even though the pollen is rich in carbohydrates. S. ionantha “Aloha Orchid” genotype has the highest percentage of viability (94.32% and germination capacity (45.73% and a rich content of carbohydrates and polygalacturonic acids. In S. rupicola and S. ionantha genotypes, the rich content of polygalacturonic acids, lipids, and carbohydrates favourably influenced the germination capacity. Spectroscopic result indicates, through different absorbance band intensity, a possible link between biochemical composition, viability, and germination capacity of Saintpaulia pollen. To determine exactly the relation between biochemistry and biological processes, it is necessary to initiate quantitative researches.

  16. FT-IR spectrometry utilization for determining changes in erythrocyte susceptibility to oxidative stress

    Science.gov (United States)

    Petibois, Cyril; Deleris, Gdrard Y. R.

    2004-07-01

    We tested the hypothesis that FT-IR spectrometry was useful for determining oxidative stress damage on erythrocytes. Endurance-trained subjects performed a standardized endurance-training session at 75% of maximal oxygen consumption each week over 19 consecutive weeks. Capillary blood samples were taken before and after test-sessions and plasma and erythrocytes were separately analyzed using Fourier-transform infrared spectrometry. Exercise-induced change in plasma concentrations and erythrocyte IR absorptivities (vC-Hn of fatty acyl moieties, vC=O and δN-H of proteins, vP=O of phospholipids, vCOO- of amino-acids, and vC-O of lactate) were monitored and compared to training level. First training weeks induced normalization of plasma concentration changes during exercise (unchanged for glucose, moderately increased for lactate, high increases for triglycerides, glycerol, and fatty acids) while erythrocyte phospholipids alteration remained elevated (P < 0.05). Further, training reduced the exercise-induced erythrocyte lactate content increase (vC-O; P < 0.05) and phospholipids alteration (vC-Hn and vP=O; P < 0.05) during exercise. These changes paralleled the lowering of exercise-induced hemoconcentration (P < 0.05) and plasma lactate concentration increase during exercise (P < 0.05). These correlated changes between plasma and erythrocyte parameters suggest that hemoconcentration and lactate acidosis (plasmatic and intracellular) are important factors contributing to reduce erythrocyte susceptibility to oxidative stress during chronic endurance training.

  17. Influence of brine-hydrocarbon interactions on FT-IR microspectroscopic analyses of intracrystalline liquid inclusions

    Energy Technology Data Exchange (ETDEWEB)

    Pironon, J. (CNRS-CREGU, Vandoeuvre-les-Nancy (France)); Barres, O. (Univ. de Nancy 1, Vandoeuvre-les-Nancy (France))

    1992-01-01

    Hydrocarbon droplets surrounded by an aqueous phase and trapped in a host crystal (i.e., fluid inclusion) are windows to the migrating hydrocarbon-water emulsions in petroleum reservoirs. Using synthetic hydrocarbon inclusions, Fourier transform infrared microspectrometric analysis shows that the interactions at the two liquid (hydrocarbon-aqueous solution) phase interface can be determined on a 20 {mu}m scale. Spectral deformation, observed for the CH stretching bands, disappears when the alkali salt concentration decreases, when the organic solvent (CCl{sub 4} or C{sub 6}H{sub 6}) concentration increases, and when the {mu}FT-IR analysis point moves off the interface. This deformation is due to the cation effect on the interaction of the OH/CH dipoles. The Na{sup +}, K{sup +} cations break the water structure and induce modifications to the OH dipole at the interface, which then modifies the CH dipole moment and the CH stretching band intensity. Knowledge of the salinity of the aqueous phase is essential for complete understanding of infrared microanalysis of hydrocarbon fluid inclusions.

  18. FT-IR microscopic mappings of early mineralization in chick limb bud mesenchymal cell cultures

    Science.gov (United States)

    Boskey, A. L.; Camacho, N. P.; Mendelsohn, R.; Doty, S. B.; Binderman, I.

    1992-01-01

    Chick limb bud mesenchymal cells differentiate into chondrocytes and form a cartilaginous matrix in culture. In this study, the mineral formed in different areas within cultures supplemented with 4 mM inorganic phosphate, or 2.5, 5.0, and 10 mM beta-glycerophosphate (beta GP), was characterized by Fourier-transform infrared (FT-IR) microscopy. The relative mineral-to-matrix ratios, and distribution of crystal sizes at specific locations throughout the matrix were measured from day 14 to day 30. The only mineral phase detected was a poorly crystalline apatite. Cultures receiving 4 mM inorganic phosphate had smaller crystals which were less randomly distributed around the cartilage nodules than those in the beta GP-treated cultures. beta GP-induced mineral consisted of larger, more perfect apatite crystals. In cultures receiving 5 or 10 mM beta GP, the relative mineral-to-matrix ratios (calculated from the integrated intensities of the phosphate and amide I bands, respectively) were higher than in the cultures with 4 mM inorganic phosphate or in the in vivo calcified chick cartilage.

  19. Forensic Hair Differentiation Using Attenuated Total Reflection Fourier Transform Infrared (ATR FT-IR) Spectroscopy.

    Science.gov (United States)

    Manheim, Jeremy; Doty, Kyle C; McLaughlin, Gregory; Lednev, Igor K

    2016-07-01

    Hair and fibers are common forms of trace evidence found at crime scenes. The current methodology of microscopic examination of potential hair evidence is absent of statistical measures of performance, and examiner results for identification can be subjective. Here, attenuated total reflection (ATR) Fourier transform-infrared (FT-IR) spectroscopy was used to analyze synthetic fibers and natural hairs of human, cat, and dog origin. Chemometric analysis was used to differentiate hair spectra from the three different species, and to predict unknown hairs to their proper species class, with a high degree of certainty. A species-specific partial least squares discriminant analysis (PLSDA) model was constructed to discriminate human hair from cat and dog hairs. This model was successful in distinguishing between the three classes and, more importantly, all human samples were correctly predicted as human. An external validation resulted in zero false positive and false negative assignments for the human class. From a forensic perspective, this technique would be complementary to microscopic hair examination, and in no way replace it. As such, this methodology is able to provide a statistical measure of confidence to the identification of a sample of human, cat, and dog hair, which was called for in the 2009 National Academy of Sciences report. More importantly, this approach is non-destructive, rapid, can provide reliable results, and requires no sample preparation, making it of ample importance to the field of forensic science.

  20. FT-IR spectroscopic imaging of reactions in multiphase flow in microfluidic channels.

    Science.gov (United States)

    Chan, K L Andrew; Kazarian, Sergei G

    2012-05-01

    Rapid, in situ, and label-free chemical analysis in microfluidic devices is highly desirable. FT-IR spectroscopic imaging has previously been shown to be a powerful tool to visualize the distribution of different chemicals in flows in a microfluidic device at near video rate imaging speed without tracers or dyes. This paper demonstrates the possibility of using this imaging technology to capture the chemical information of all reactants and products at different points in time and space in a two-phase system. Differences in the rates of chemical reactions in laminar flow and segmented flow systems are also compared. Neutralization of benzoic acid in decanol with disodium phosphate in water has been used as the model reaction. Quantitative information, such as concentration profiles of reactant and products, can be extracted from the imaging data. The same feed flow rate was used in both the laminar flow and segmented flow systems. The laminar flow pattern was achieved using a plain wide T-junction, whereas the segmented flow was achieved by introducing a narrowed section and a nozzle at the T-junction. The results show that the reaction rate is limited by diffusion and is much slower with the laminar flow pattern, whereas the reaction is completed more quickly in the segmented flow due to better mixing.

  1. DIFERENCIACIÓN DE ESPECIE MICOBACTERIANA POR FT-IR (ESPECTROSCOPIA INFRARROJA CON TRANSFORMADA DE FOURIER

    Directory of Open Access Journals (Sweden)

    JORGE ANDRÉS CUÉLLAR GIL

    2011-01-01

    Full Text Available Se trabajó con espectroscopía infrarroja transformada de Fourier (FT-IR para diferenciar diez especies de micobacterias. Mycobacterium intracelullare y M. fortuitum (ATCC, M. flavensces , M. smegmatis , M. chelone , M. gordonae , M. triviale , M. vaccae , M. terrae y M. nonchromogenicum (IP. Como control de diferenciación de género se incluyó Staphylococcus aureus , Streptococcus viridans y Streptococcus pyogenes , Klebsiella pneumoniae y Escherichia coli , cada especie se corrió por triplicado en KBr y ATR. Los espectros se analizaron según el método de diferenciación de componentes principales, y se realizaron derivadas de primer orden (D1 en modalidad de transmisión usando la pastilla de KBr y la base ATR, además se diseñó una biblioteca espectral con la primera derivada de ATR. La sensibilidad de detección fue de 100% al trabajar con KBr y el nivel de diferenciación fue de 100% en tres de cuatro muestras problema.

  2. The deposition characteristics of copper(I) compounds for CVD by FT-IR spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Hardcastle, F.D.; Peden, C.H.F.; Omstead, T.R.; Blewer, R.S. [Sandia National Labs., Albuquerque, NM (United States); Farkas, J.; Hampden-Smith, M.J.; Kodas, T.T. [New Mexico Univ., Albuquerque, NM (United States)

    1991-12-31

    Fourier transform-infrared spectroscopy (FT-IR) was used to investigate the adsorption and thermally-induced decomposition of copper (I) {beta}-diketonate precursors of the type (hfac)CuL, where hfac is the hexafluoroacetylacetonate bidentate ligand and L is trimethylphosphine or 1,5-cyclooctadiene. The (hfac)CuPMe{sub 3} precursor desorbs from the surface at very low temperatures whereas the (hfac)Cu(1,5-COD) dissociates on adsorption, liberating 1,5-COD and leaving a surface(hfac)Cu complex which can subsequently disproportionate. Evidence is provided for hydrogen-bonding between the hfac ligand and the surface silanols for (hfac)CuPMe{sub 3}, but not for (hfac)Cu(1,5-COD). These results are consistent with the selective behavior of these precursors for copper deposition and suggest that the selectivity of the (hfac)CuPMe{sub 3} and (hfac)Cu(1, 5-COD) precursors may be due to the ability of the hfac ligand to hydrogen bond to the surface silanol groups.

  3. The deposition characteristics of copper(I) compounds for CVD by FT-IR spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Hardcastle, F.D.; Peden, C.H.F.; Omstead, T.R.; Blewer, R.S. (Sandia National Labs., Albuquerque, NM (United States)); Farkas, J.; Hampden-Smith, M.J.; Kodas, T.T. (New Mexico Univ., Albuquerque, NM (United States))

    1991-01-01

    Fourier transform-infrared spectroscopy (FT-IR) was used to investigate the adsorption and thermally-induced decomposition of copper (I) {beta}-diketonate precursors of the type (hfac)CuL, where hfac is the hexafluoroacetylacetonate bidentate ligand and L is trimethylphosphine or 1,5-cyclooctadiene. The (hfac)CuPMe{sub 3} precursor desorbs from the surface at very low temperatures whereas the (hfac)Cu(1,5-COD) dissociates on adsorption, liberating 1,5-COD and leaving a surface(hfac)Cu complex which can subsequently disproportionate. Evidence is provided for hydrogen-bonding between the hfac ligand and the surface silanols for (hfac)CuPMe{sub 3}, but not for (hfac)Cu(1,5-COD). These results are consistent with the selective behavior of these precursors for copper deposition and suggest that the selectivity of the (hfac)CuPMe{sub 3} and (hfac)Cu(1, 5-COD) precursors may be due to the ability of the hfac ligand to hydrogen bond to the surface silanol groups.

  4. Analysis of a Brazilian baroque sculpture using Raman spectroscopy and FT-IR

    Science.gov (United States)

    Freitas, Renato P.; Ribeiro, Iohanna M.; Calza, Cristiane; Oliveira, Ana L.; Felix, Valter S.; Ferreira, Douglas S.; Pimenta, André R.; Pereira, Ronaldo V.; Pereira, Marcelo O.; Lopes, Ricardo T.

    2016-02-01

    In this study, samples were taken from the sculpture of Our Lady of Sorrows and analyzed by Raman spectroscopy and FT-IR. This sculpture has been dated to the early eighteenth century. Samples were also examined using optical microscopy and Energy Dispersive Spectroscopy (EDS). Based on chemical analysis, the pigments vermilion [HgS], massicot [PbO] and azurite [Cu3(CO3)2(OH)2] were found in the sculpture polychrome. The results indicate that the green polychrome of the sculpture's mantle comes from the blending of massicot and azurite. Because the literature reports that the mantle of the Our Lady of Sorrows sculpture is blue, the mixing of these pigments results from a production error. The results also indicate the presence of Au in the sculpture, which indicates the originality of the piece. The results from this study helped restorers to choose the appropriate procedures for intervening in the sculpture and contributed to the knowledge about the manufacturing process of Brazilian baroque sculptures.

  5. FT-IR Studies of Cerium Oxide Nanoparticles and Natural Zeolite Materials

    Directory of Open Access Journals (Sweden)

    Oana Lelia Pop

    2015-05-01

    Full Text Available An emerging topic of our days is nanoscience and nanotechnology successfully applied in the food industry. Characteristics such as size, surface area and morphology can modify the basic properties and the chemical reactivity of the nanomaterials. The breakthrough of innovative materials, processes, and phenomena at the nanoscale, as well as the progress of new experimental and theoretical techniques for research, supply novel opportunities for the expansion of original nanosystems and nanostructured materials. These study examine two types of nanoparticles, namely cerium oxide nanoparticles (CeO2 NP and natural zeolites. In view of the importance of CeO2 NP in various biological applications, the primary objective of this study is to characterise four samples of CeO2 NP in order to understand the role of the synthesis process in the final product. Nanocrystalline natural zeolites are materials with interesting properties which allows them to be used as adjuvant in many therapies. The characterisation of CeO2 NP and two types of natural zeolites using Fourier Transform Infrared (FT-IR spectroscopy is described. Therefore, this study examined two types of nanomaterials, namely cerium oxide nanoparticles and zeolites, for further applications on microorganisms and living cells.

  6. Background defining during the imine formation reaction in FT-IR liquid cell

    Science.gov (United States)

    Namli, Hilmi; Turhan, Onur

    2006-05-01

    Imine formation is a very important chemical reaction because of its relevance to biological process. Therefore, it is crucial to follow whole reaction process in detail. The current work performed to monitor the whole imination reaction in real time in liquid cell by FT-IR spectroscopy. The complex spectral futures due to solvent, unreacted reagents, acid catalysis and other additives are eliminated by defining a background at the beginning or at any time during the reaction. This procedure also makes it possible to monitor the changes in the concentration of each component in the liquid cell. The consumption of the functional groups of the reagents results in absorbance due to the direct difference spectra while the appearance of functional groups is monitored as percentage transmittance. The concentration changes in the cell arising from the reaction gives the product spectra without having to isolate it from the mixture. It is also possible to see the intermediates appearing and disappearing during the reaction. This report also illustrates a brief application of the technique by time dependence of the peak highs in absorption (ABS) mode.

  7. An FT-IR study on intramolecular hydrogen-bonding in ethylene glycol derivatives

    Science.gov (United States)

    Singelenberg, F. A. J.; van der Maas, J. H.; Kroon-Batenburg, L. M. J.

    1991-05-01

    The OH-streching region of a number of mono-alkyl ethers of (poly) ethylene glycols in dilute CCl 4 solution has been investigated by FT-IR. Non-H-bonded conformers are observed in addition to intramolecularly H-bonded ones. Different H-bonds can be distinguished when more than one ether-oxygen is present. The frequency of the non-bonded conformer is identical for all compounds and the same holds for the 5-R conformer. Furthermore the relative intensities of these peaks are identical in all spectra. The OH-frequency of the 8-R and 11-R conformers depends on the length and the type of the chain substituted at O(3) and O(4), respectively. MM2 calculations have been carried out for some of the compounds. The stability of the conformers proves to be in the order 11-R&>;5-R&>;;8-R&>; non-H-bonded. Interatomic distances and angles indicate that the H-bonds in the 8-R and 11-R conformers are bifurcated and "trifurcated", respectively.

  8. Evaluation of angle dependence in spectral emissivity of ceramic tiles measured by FT-IR

    Science.gov (United States)

    Kobayashi, C.; Ogasawara, N.; Yamada, H.; Yamada, S.; Kikuchi, T.

    2015-05-01

    Ceramic tiles are widely used for building walls. False detections are caused in inspections by infrared thermography because of the infrared reflection and angle dependence of emissivity. As the first problem, ceramic tile walls are influenced from backgrounds reflection. As the second problem, in inspection for tall buildings, the camera angles are changed against the height. Thus, to reveal the relation between the emissivity and angles is needed. However, there is very little data about it. It is impossible to decrease the false detection on ceramic tile walls without resolving these problems; background reflection and angle dependence of emissivity. In this study, the angle problem was investigated. The purpose is to establish a revision method in the angle dependence of the emissivity for infrared thermography. To reveal the relation between the emissivity and angles, the spectral emissivity of a ceramic tile at various angles was measured by FT-IR and infrared thermographic instrument. These two experimental results were compared with the emissivity-angle curves from the theoretical formula. In short wavelength range, the two experimental results showed similar behavior, but they did not agree with the theoretical curve. This will be the subject of further study. In long wavelength range, the both experimental results almost obeyed the theoretical curve. This means that it is possible to revise the angle dependence of spectral emissivity, for long wavelength range.

  9. Analysis of urinary stone constituents using powder X-ray diffraction and FT-IR

    Indian Academy of Sciences (India)

    Pragnya A Bhatt; Parimal Paul

    2008-03-01

    Constituents of urinary stones obtained from various patients from western part of India, which is a highly urinary stone disease-prone area, have been analysed. Eight stones from four patients were collected through urologists and have been analysed using powder X-ray diffraction and FT-IR. Thermogravimetric analysis (TGA) and scanning electron microscopic (SEM) image of selected samples were also carried out. The analysis revealed that calcium oxalate monohydrate, which is also known as whewellite, is the common constituent of all of the stones, particularly at the initial stage of stone formation. However, multi phases viz. whewellite phase, and hydroxyl and carbonate apatite phases are also detected in the case of third and fourth patients, from where multiple stones were obtained. Interestingly, in these mixed phase stones the concentration of whewellite decreases with increasing the concentration of apatite phases. Thermal behaviour of the whewellite phase was studied by TGA and variable temperature XRD analysis. Morphology of the whewellite and apatite phases, examined by SEM image, has also been reported.

  10. Determinação do teor de NR/SBR em misturas: associação de dados DTG e FT-IR Determination of NR/SBR content in blends: combining DTG and FT-IR data

    OpenAIRE

    Rita C. L. Dutra; Milton F. Diniz; Ribeiro,Ana P.; Lourenço,Vera L.; Silvana N. Cassu; Azevedo,Margarete F. P.

    2004-01-01

    Misturas contendo teor conhecido de borracha natural (NR) e copolímero de butadieno e estireno (SBR) foram preparadas nos laboratórios do CTA e do IFOCA como amostras de referência para a elaboração de uma curva analítica, visando à determinação do teor de NR e SBR por análise pirólise/FT-IR. Termogravimetria foi usada para determinar o teor real de NR e SBR nas misturas por meio da razão entre as alturas dos picos da curva derivada (DTG). As bandas FT-IR escolhidas na região MIR foram 885 cm...

  11. Analysis of Organic Inclusions Using Fluorescence Microscopy and Micro-FT. IR Techniques

    Institute of Scientific and Technical Information of China (English)

    李荣西; 杜向民; 迟元林

    2001-01-01

    Organic inclusions from the Shahejie Formation of the Eogene period in the Bohai Gulf Basin, eastern China, were examined using micro-FT. IR and fluorescence microscopy in addition to the measurement of their homogenization temperatures (Th). Two populations of organic inclusions were recognized, the primary and the secondary organic inclusions. The primary organic inclusions contain organic materials with relatively long alkyl chains (the carbon atom number is 15 to 17), whereas the secondary organic inclusions contain a certain amount of H2S besides organic materials which have relatively short alkyl chains with the carbon atom number of 5 to 6. The Th values of the primary organic inclusions are within the range of 87-91℃, lower than those of the secondary organic inclusions ( Th = 98 - 105℃ ), suggesting that the primary organic inclusions experienced a lower degree of thermal evolution than the secondary inclusions. This inference is consistent with the fluorescence spectroscopic characteristics and parameters ( Tmax, Q values) of the organic inclusions. Data from the organic inclusions together with the petroleum geology setting revealed that the primary inclusions resulted from the migration of hydrocarbons generated within the strata they are hosted, whereas the secondary organic inclusions were trapped in the process of secondary hydrocarbons expelled out of the source rocks to the locations where they were accumulated. The thermal properties of the organic inclusions are consistent with the maturation of the oil generated from the Shahejie Formation. The abundance of the organic inclusions and their characteristics indicate that the member Es3 of the Shahejie Formation is highly potential for oil accumulation. The results could provide essential clues to petroleum exploration in the Bohai Gulf Basin.

  12. Analysis of Organic Inclusions Using Fluorescence Microscopy and Micro-FT.IR Techniques

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Organic inclusions from the Shahejie Formation of the Eogene period in the Bohai Gulf Basin,eastern China,were examined using micro-FT.IR and fluorescence microscopy in addition to the measurement of their homogenization temperatures(Th).Two populations of organic inclusions were recognized,the primary and the secondary organic inclusions.The primary organic inclusions contain organic materials with relatively long alkyl chains(the carbon atom number is 15 to 17),whereas the secondary organic inclusions contain a certain amount of H2S besides organic materials which have relatively short alkyl chains with the carbon atom number of 5 to 6.The Th values of the primary organic inclusions within the rage of 87-91℃,lower than those of the secondary organic inclusions(Th=98-105℃),sugesting that the primary organic inclusions experienced a lower degree of thermal evolution than the secondary inclusions.This inference is consistent with the fluorescence spectroscopic characteristics and parameters(Tmax,Q values)of the organic inclusions.Data from the organic inclusions together with the petroleum geology setting revealed that the primary inclusions resulted from the migration of hydrocarbons generated within the strata they are hosted,whereas the secondary organic inclusions were trapped in the process of secondary hydrocarbons expelled out of the source rocks to the locations where they were accumulated.The thermal properties of the organic inclusions are consistent with the maturation of the oil generated from the Shahejie Formation.The abundance of the organic inclusions and their characteristics indicate that the member Es3 of the Shaheije Formation is highly potential for oil accumulation.The results could provide essential coues to petroleum exploration in the Bohai Gulf Basic.

  13. Fluorescence EEM and FT-IR analyses for examination of soil organic matter compositions affected by incubation conditions

    Science.gov (United States)

    Kim, Eun-Ah; Vo-Minh Nguyen, Hang; Choi, Jung Hyun

    2015-04-01

    This study investigated the effects of soil drying-rewetting, nitrogen deposition, and temperature rise on the changes in dissolved soil organic matter quantities and their compositions.A PARAFAC method was employed to analyze the changes in the sub-fractions of fluorescent DOM components, which revealed that the dry forest soil accumulated relatively more amino acid type DOM than humic-like substances whereas the other soil groups showed the opposite trend.Nitrogen deposition, and temperature rise did not induce significant changes in the fluorescent DOM components. FT-IR analysis results were compared with the fluorescence EEM results, which provided complementary information about the characteristic functional groups of DOM. A principal component analysis (PCA) with the PARAFAC component scores, and the intensity ratios of representative FT-IR peaks gave a comprehensive interpretation on the changes of DOM compositions in response to the variations in the incubation conditions.

  14. An FT-IR and DFT study of the free and solvated 4-(imidazol-1-yl)phenol.

    Science.gov (United States)

    Yurdakul, Şenay; Badoğlu, Serdar

    2015-11-05

    In this study, FT-IR spectrum of 4-(imidazol-1-yl)phenol was recorded. Its vibrational frequencies and modes were determined. Vibrational assignments were proposed with the help of B3LYP/6-311++G(d,p) level of calculations. Three possible dimeric forms of the molecule were investigated theoretically. Besides, solvent effects on the structure, vibrational frequencies, and atomic charges were studied theoretically. Water, dimethyl sulfoxide, and ethanol were the solvents considered. Experimental FT-IR spectrum in DMSO solution was recorded and compared with solid phase experimental data. DFT B3LYP combined with polarized continuum model (PCM) was employed to characterize the solvent effects. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. FT-IR, FT-Raman spectroscopic study of carotenoids from saffron ( Crocus sativus L.) and some derivatives

    Science.gov (United States)

    Tarantilis, Petros A.; Beljebbar, Abdelilah; Manfait, Michel; Polissiou, Moschos

    1998-04-01

    The carotenoids of saffron, crocins (CRCs), were extracted and their derivatives, dimethylcrocetin (DMCRT) and crocetin (CRT) were prepared from the extract by alkaline hydrolysis in methanol (DMCRT) and by alkaline hydrolysis in water followed by acidification (CRT), respectively. FT-IR, FT-Raman spectroscopies were used to study these compounds. The FT-IR spectra of CRCs, DMCRT and CRT have characteristic absorbance bands between 1706 and 1664 cm -1 ( νCO) and in the region between 1243 and 1228 cm -1 ( νC-O). Two main Raman lines were observed near 1540 and 1166 cm -1 which are respectively assigned to ( νCC) and ( νC-C) stretching modes.

  16. Probing organic ligands and their binding schemes on nanocrystals by mass spectrometric and FT-IR spectroscopic imaging

    Science.gov (United States)

    Son, Jin Gyeong; Choi, Eunjin; Piao, Yuanzhe; Han, Sang Woo; Lee, Tae Geol

    2016-02-01

    We report an analysis method to identify conjugated ligands and their binding states on semiconductor nanocrystals based on their molecular information. Surface science techniques, such as time-of-flight secondary-ion mass spectrometry (ToF-SIMS) and FT-IR spectroscopy, are adopted based on the micro-aggregated sampling method. Typical trioctylphosphine oxide-based synthesis methods of CdSe/ZnS quantum dots (QDs) have been criticized because of the peculiar effects of impurities on the synthesis processes. Because the ToF-SIMS technique provides molecular composition evidence on the existence of certain ligands, we were able to clearly identify n-octylphosphonic acid (OPA) as a surface ligand on CdSe/ZnS QDs. Furthermore, the complementary use of the ToF-SIMS technique with the FT-IR technique could reveal the OPA ligands' binding state as bidentate complexes.We report an analysis method to identify conjugated ligands and their binding states on semiconductor nanocrystals based on their molecular information. Surface science techniques, such as time-of-flight secondary-ion mass spectrometry (ToF-SIMS) and FT-IR spectroscopy, are adopted based on the micro-aggregated sampling method. Typical trioctylphosphine oxide-based synthesis methods of CdSe/ZnS quantum dots (QDs) have been criticized because of the peculiar effects of impurities on the synthesis processes. Because the ToF-SIMS technique provides molecular composition evidence on the existence of certain ligands, we were able to clearly identify n-octylphosphonic acid (OPA) as a surface ligand on CdSe/ZnS QDs. Furthermore, the complementary use of the ToF-SIMS technique with the FT-IR technique could reveal the OPA ligands' binding state as bidentate complexes. Electronic supplementary information (ESI) available: Additional data (Fig. S1-S5). See DOI: 10.1039/c5nr07592k

  17. Identification of urushi coated films taken from ancient Buddha images by using PIXE, FT-IR, and organic elemental analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kagemori, N.; Umemura, K.; Yoshimura, T.; Inoue, M.; Kawai, S. [Wood Research Institute, Kyoto Univ., Uji, Kyoto (Japan); Yano, K. [Tokyo National University of Fine Arts and Music, Uenokouen, Tokyo (Japan); Sera, K. [Cyclotron Research Center, Iwate Medical Univ., Takizawa, Iwate (Japan); Futatsugawa, S. [Nishina Memorial Cyclotron Center, Japan Radioisotope Association, Takizawa, Iwate (Japan); Nakamura, Y. [Kyoto National Museum, Higashiyama, Kyoto (Japan)

    1999-07-01

    Six types of samples including urushi, urushi tree and black coating films taken from ancient Buddha images were examined by analyses of PIXE, organic element and FT-IR to identify with urushi or another material. Based on the results of three analytical experiments above mentioned, the coating materials aging over hundreds of years were identified with weathered urushi films mixed with other material. Further investigation may reveal the urushi coating techniques used in the past. (author)

  18. Application of FT-IR microspectroscopy to the study of an injectable composite for bone and dental surgery.

    OpenAIRE

    Weiss, Pierre; Bohic, Sylvain; Lapkowski, Mieczyslaw; Daculsi, Guy

    1998-01-01

    Hydroxypropylmethylcellulose (HPMC) of high-viscosity grade is used as a ligand for a bioactive calcium phosphate ceramic (the filler) in a ready-to-use injectable sterilized biomaterial for bone and dental surgery. Application of physico-chemical methods such as XPS, NMR, or Raman spectroscopy encounters difficulties when used to study such a multiphased material. This paper reports on the application of FT-IR microspectroscopy (FT-IRM) for the investigation of inorganic and organic phases o...

  19. FT-IR, Raman and thermoluminescence investigation of P 2O 5-BaO-Li 2O glass system

    Science.gov (United States)

    Ivascu, C.; Timar Gabor, A.; Cozar, O.; Daraban, L.; Ardelean, I.

    2011-05-01

    The 0.5P 2O 5· xBaO·(0.5- x) Li 2O glass system (0 ⩽ x ⩽ 0.5 mol%) is investigated by FT-IR, Raman and thermoluminescence as a possible dosimetic material. FT-IR and Raman spectra show structural network modifications with the composition variations of the studied glasses. The predominant absorption band from IR spectra is attributed to the symmetric stretching vibrations of P = O double bonds. Raman spectra of the studied glasses contain also typical phosphate glasses bands. Thus the band at ˜700 cm -1 is assigned to symmetric stretching vibrations of P-O-P groups and that from ˜1158 cm -1 is attributed to symmetric stretching motions of the non-bridging oxygen (NBO) atoms bonded to phosphorous atoms (PO 2) in phosphate tetrahedron. Finally FT-IR and Raman spectroscopies revealed a local network structure mainly based on Q 2 and Q 3 tetrahedrons connected by P-O-P linkages. Luminescence investigations show that by adding modifier oxides to phosphate glass dose dependent TL signals result upon irradiation. Thus P 2O 5-BaO-Li 2O glass system is a possible candidate material for dosimetry in the high dose range (>10 Gy).

  20. Biochemical Monitoring of Spinal Cord Injury by FT-IR Spectroscopy—Effects of Therapeutic Alginate Implant in Rat Models

    Science.gov (United States)

    Uckermann, Ortrud; Sitoci-Ficici, Kerim H.; Later, Robert; Beiermeister, Rudolf; Doberenz, Falko; Gelinsky, Michael; Leipnitz, Elke; Schackert, Gabriele; Koch, Edmund; Sablinskas, Valdas; Steiner, Gerald; Kirsch, Matthias

    2015-01-01

    Spinal cord injury (SCI) induces complex biochemical changes, which result in inhibition of nervous tissue regeneration abilities. In this study, Fourier-transform infrared (FT-IR) spectroscopy was applied to assess the outcomes of implants made of a novel type of non-functionalized soft calcium alginate hydrogel in a rat model of spinal cord hemisection (n = 28). Using FT-IR spectroscopic imaging, we evaluated the stability of the implants and the effects on morphology and biochemistry of the injured tissue one and six months after injury. A semi-quantitative evaluation of the distribution of lipids and collagen showed that alginate significantly reduced injury-induced demyelination of the contralateral white matter and fibrotic scarring in the chronic state after SCI. The spectral information enabled to detect and localize the alginate hydrogel at the lesion site and proved its long-term persistence in vivo. These findings demonstrate a positive impact of alginate hydrogel on recovery after SCI and prove FT-IR spectroscopic imaging as alternative method to evaluate and optimize future SCI repair strategies. PMID:26559822

  1. Biochemical Monitoring of Spinal Cord Injury by FT-IR Spectroscopy--Effects of Therapeutic Alginate Implant in Rat Models.

    Directory of Open Access Journals (Sweden)

    Sandra Tamosaityte

    Full Text Available Spinal cord injury (SCI induces complex biochemical changes, which result in inhibition of nervous tissue regeneration abilities. In this study, Fourier-transform infrared (FT-IR spectroscopy was applied to assess the outcomes of implants made of a novel type of non-functionalized soft calcium alginate hydrogel in a rat model of spinal cord hemisection (n = 28. Using FT-IR spectroscopic imaging, we evaluated the stability of the implants and the effects on morphology and biochemistry of the injured tissue one and six months after injury. A semi-quantitative evaluation of the distribution of lipids and collagen showed that alginate significantly reduced injury-induced demyelination of the contralateral white matter and fibrotic scarring in the chronic state after SCI. The spectral information enabled to detect and localize the alginate hydrogel at the lesion site and proved its long-term persistence in vivo. These findings demonstrate a positive impact of alginate hydrogel on recovery after SCI and prove FT-IR spectroscopic imaging as alternative method to evaluate and optimize future SCI repair strategies.

  2. [The effect of Tween-80 on the differentiation of Trichophyton mentagrophytes and Trichophyton rubrum strains with FT-IR spectroscopy].

    Science.gov (United States)

    Ergın, Çagri; İlkit, Macit; Gök, Yaşar; Çon, Ahmet Hilmi; Özel, Mustafa Zafer; Kabay, Nilgün; Döğen, Aylin; Baygu, Yasemin

    2014-07-01

    Trichophyton mentagrophytes and Trichophyton rubrum, are two of the frequently identified dermatophyte species in routine microbiology laboratories. Although newer technologies may assist in species-level identification, direct application of these methods usually require improvement in order to obtain reliable identification of these species. Earlier data have shown that dermatophytes may be identified with FT-IR spectroscopy although there are some limitations. In particular, the organic bond ranges in FT-IR spectra showed more irregularity because of the eucaryotic complexity of the molds. In this study, Tween-80 which is an inorganic molecule, was added to the dermatophyte growth medium in order to investigate its effect on FT-IR spectroscopy analysis of dermatophytes. Nine reference dermatophyte strains [5 T.mentagrophytes complex (T.asteroides CBS 424.63, T.erinacei CBS 344.79, CBS 511.73, CBS 677.86, T.mentagrophytes CBS 110.65) and 4 T.rubrum complex strains with different morphotypes (T.fluviomuniense CBS 592.68, T.kuryangei CBS 422.67, T.raubitschekii CBS 102856, T.rubrum CBS 392.58)] were included in the study. All strains were cultured on Sabouraud glucose agar either with or without 1% Tween-80 for three weeks. After the incubation period, superficial scrapings from each dermatophyte colony were analyzed using FT-IR spectroscopy. All measurements were performed in transmission mode between 4400 and 400 cm-1. Numerous spectral window data were analyzed by principal component analysis and hierarchical clustering was performed. The second derivations of spectral ranges revealed clear grouping of T.mentagrophytes complex and T.rubrum complex in association over five separate spectral ranges. The findings also showed that while all of the T.mentagrophytes strains contained lipid compounds in their mold structure after Tween-80 incubation (pIR spectroscopy. This effect might be attributed to the possible transfer of lipid compounds from culture to cell

  3. KARAKTERISASI SENYAWA POLIOKSOMETALAT TIPE KEGGIN TERSUBSTITUSI VANADIUM MENGGUNAKAN FT-IR DAN 51V NMR

    Directory of Open Access Journals (Sweden)

    Aldes Lesbani

    2012-05-01

    Full Text Available Sintesis dan karakterisasi senyawa polioksometalat tipe Keggin yakni Rb2K2[γ-SiV2W10O38(OH2]•nH2O dan H4[γ-SiV2W10O38(OH2]•nH2O telah dilakukan menggunakan FT-IR dan spektroskopi 51V NMR. Senyawa polioksometalat Rb2K2[γ-SiV2W10O38(OH2]•nH2O ditransformasi menjadi H4[γ-SiV2W10O38(OH2]•nH2O melalui metode pertukaran ion menggunakan asam klorida. Spektrum 51V NMR dari Rb2K2[γ-SiV2W10O38(OH2]•nH2O menunjukkan pergeseran kimia pada -586.94 ppm. Vibrasi utama yang menunjukkan gugus fungsional senyawa Rb2K2[γ-SiV2W10O38(OH2]•nH2O muncul pada bilangan gelombang 1041 cm-1, 972 cm-1 (n W=O, 914 cm-1 (n Si-O, 870 cm-1 (nW-Oe-W, 781 cm-1 (n W-Oc-W, 565 cm-1 dan 534 cm-1. Pergeseran kimia 51V NMR dari senyawa polioksometalat H4[γ-SiV2W10O38(OH2]•nH2O memberikan satu puncak pada -586.77 ppm. Pergeseran kimia antara senyawa Rb2K2[γ-SiV2W10O38(OH2]•nH2O dan H4[γ-SiV2W10O38(OH2]•nH2O tidak berubah yang disebabkan oleh kemiripan struktur utama di antara dua senyawa polioksometalat tersebut. Vibrasi utama dari senyawa polioksometalat H4[γ-SiV2W10O38(OH2]•nH2O juga mempunyai kemiripan dengan senyawa polioksometalat Rb2K2[γ-SiV2W10O38(OH2]•nH2O yang disebabkan hanya kation yang berubah menjadi asam.

  4. DIFERENCIACIÓN DE ESPECIE MICOBACTERIANA POR FT-IR (Espectroscopia Infrarroja con Transformada de Fourier

    Directory of Open Access Journals (Sweden)

    Arrubla Carlos Roberto

    2011-08-01

    Full Text Available

    Se trabajó con espectroscopía infrarroja transformada de Fourier (FT-IR para diferenciar diez especies de micobacterias. Mycobacterium intracelullare y M. fortuitum (ATCC, M.flavenscesM.  smegmatisM.  cheloneM.  gordonaeM.  trivialeM.  vaccaeM.  terrae y M.nonchromogenicum (IP. Como control de diferenciación de género se incluyó  Staphylococcus
    aureusStreptococcus viridans y Streptococcus pyogenesKlebsiella pneumoniae y Escherichia coli,
    cada especie se corrió por triplicado en KBr y ATR. Los espectros se analizaron según el método de diferenciación de componentes principales, y se realizaron derivadas de
    primer orden (D1 en modalidad de transmisión usando  la pastilla de KBr y  la base ATR, además se diseñó una biblioteca espectral con  la primera derivada de ATR. La
    sensibilidad de detección fue de 100% al trabajar con KBr y el nivel de diferenciación fue de 100% en tres de cuatro muestras problema.

  5. Determinação do teor de NR/SBR em misturas: associação de dados DTG e FT-IR Determination of NR/SBR content in blends: combining DTG and FT-IR data

    Directory of Open Access Journals (Sweden)

    Rita C. L. Dutra

    2004-12-01

    Full Text Available Misturas contendo teor conhecido de borracha natural (NR e copolímero de butadieno e estireno (SBR foram preparadas nos laboratórios do CTA e do IFOCA como amostras de referência para a elaboração de uma curva analítica, visando à determinação do teor de NR e SBR por análise pirólise/FT-IR. Termogravimetria foi usada para determinar o teor real de NR e SBR nas misturas por meio da razão entre as alturas dos picos da curva derivada (DTG. As bandas FT-IR escolhidas na região MIR foram 885 cm-1 (A1 para NR e 699 cm-1 (A2 para SBR. Os valores de absorvância relativa (A1/A2 versus a relação NR/SBR, obtida a partir dos dados fornecidos pela análise DTG, foram usados para construir uma curva com uma boa correlação linear (R=0,998, a qual possibilita determinar os teores de NR e SBR em misturas onde os componentes têm a mesma composição química.Blends with known contents of natural rubber (NR and butadiene-styrene copolymer (SBR were prepared at CTA and IFOCA laboratories as sample references for producing an analytical curve to determine the contents of NR and SBR via pyrolysis/FT-IR analysis. Thermogravimetry was used to quantify the real content of NR and SBR in the blends through the ratio between the intensity of the peaks in the derivative curve (DTG. The FT-IR analytical bands chosen at MIR region were 885 cm-1 (A1 for NR and 699 cm-1 (A2 for SBR. Values of relative absorbance (A1/A2 versus the NR/SBR contents data obtained from DTG analysis were used to construct an analytical curve with a good linear correlation (R=0.998 which allows one to determine contents of NR and SBR in blends of similar composition.

  6. Caracterização por FT-IR da superfície de borracha EPDM tratada via plasma por micro-ondas FT-IR characterization of EPDM rubber surface treated by microwave plasma

    Directory of Open Access Journals (Sweden)

    Renata P. dos Santos

    2012-01-01

    Full Text Available A superfície de uma borracha de etileno-propileno-dieno (EPDM vulcanizada foi modificada via plasma por microondas, com gases Ar, Ar/O2, N2/O2 e N2/H2, tendo como objetivo melhorar as propriedades adesivas da superfície. A técnica FT-IR/UATR foi escolhida para caracterizar as superfícies após tratamento, pois apresentou menor interferência dos ingredientes da formulação da EPDM, dentre as técnicas analisadas (ATR/KRS-5 e Ge. Grupos oxigenados foram inseridos na superfície da amostra tratada, mesmo quando não foi utilizado o oxigênio, pois estes grupos foram formados quando a superfície ativada foi exposta à atmosfera. Já em tratamentos contendo N2, grupos oxigenados e possíveis grupos nitrogenados foram identificados por FT-IR. Redução nos valores do ângulo de contato, aumento no trabalho de adesão e aumento no ensaio de resistência ao descascamento (EPDM × Poliuretano foram observados após tratamento com Ar e N2/H2, resultando em melhora nas propriedades adesivas da superfície tratada.The surface of a vulcanized ethylene propylene diene monomer (EPDM rubber was modified by microwave plasma in Ar, Ar/O2, N2/O2 and N2/H2 in order to improve the adhesion properties. Surface modification was characterized by FT-IR/UATR, because this technique showed smaller interference of ingredients of EPDM formulation in comparison with other techniques used (ATR KRS-5 and Ge. Oxygenated groups were introduced in the EPDM surface after treatment, even in treatments without oxygen. Theses groups were formed when the activated surface was exposed to the atmosphere. In treatments with nitrogen, oxygenated and possible nitrogenated groups were identified by FT-IR. Reduction in the contact angle, increase in the work of adhesion and increase in the peel strength (EPDM × Polyurethane were observed after treatment with Ar and N2/H2, resulting in improved adhesion properties of the modified surface.

  7. Avaliação do uso de técnicas PIR-G/FT-IR para caracterização de elastômeros Evaluation of PIR-G/FT-IR techniques for characterization of elastomers

    OpenAIRE

    Sanches,Natália B.; Milton F. Diniz; Tiago B. Reis; Silvana N. Cassu; Rita C. L. Dutra

    2006-01-01

    A técnica de pirólise gasosa, em bico de Bunsen, para análise por espectroscopia no infravermelho com transformada de Fourier (PIR-G/FT-IR) foi aplicada a diferentes borrachas, incluindo algumas misturas. Foi observado que é possível diferenciar os tipos de elastômeros por meio de análise de produtos gasosos de pirólise, inclusive aqueles que apresentam espectros IR de pirolisados líquidos similares, como é o caso de CIIR e BIIR, NR/SBR e EPDM/SBR, SBR/BR e SBR.Pyrolysis and infrared spectros...

  8. Caracterização por FT-IR da superfície de borracha EPDM tratada via plasma por micro-ondas FT-IR characterization of EPDM rubber surface treated by microwave plasma

    Directory of Open Access Journals (Sweden)

    Renata P. dos Santos

    2012-01-01

    Full Text Available A superfície de uma borracha de etileno-propileno-dieno (EPDM vulcanizada foi modificada via plasma por microondas, com gases Ar, Ar/O2, N2/O2 e N2/H2, tendo como objetivo melhorar as propriedades adesivas da superfície. A técnica FT-IR/UATR foi escolhida para caracterizar as superfícies após tratamento, pois apresentou menor interferência dos ingredientes da formulação da EPDM, dentre as técnicas analisadas (ATR/KRS-5 e Ge. Grupos oxigenados foram inseridos na superfície da amostra tratada, mesmo quando não foi utilizado o oxigênio, pois estes grupos foram formados quando a superfície ativada foi exposta à atmosfera. Já em tratamentos contendo N2, grupos oxigenados e possíveis grupos nitrogenados foram identificados por FT-IR. Redução nos valores do ângulo de contato, aumento no trabalho de adesão e aumento no ensaio de resistência ao descascamento (EPDM × Poliuretano foram observados após tratamento com Ar e N2/H2, resultando em melhora nas propriedades adesivas da superfície tratada.The surface of a vulcanized ethylene propylene diene monomer (EPDM rubber was modified by microwave plasma in Ar, Ar/O2, N2/O2 and N2/H2 in order to improve the adhesion properties. Surface modification was characterized by FT-IR/UATR, because this technique showed smaller interference of ingredients of EPDM formulation in comparison with other techniques used (ATR KRS-5 and Ge. Oxygenated groups were introduced in the EPDM surface after treatment, even in treatments without oxygen. Theses groups were formed when the activated surface was exposed to the atmosphere. In treatments with nitrogen, oxygenated and possible nitrogenated groups were identified by FT-IR. Reduction in the contact angle, increase in the work of adhesion and increase in the peel strength (EPDM × Polyurethane were observed after treatment with Ar and N2/H2, resulting in improved adhesion properties of the modified surface.

  9. FT-IR spectroscopy: A powerful tool for studying the inter- and intraspecific biodiversity of cultivable non-Saccharomyces yeasts isolated from grape must.

    Science.gov (United States)

    Grangeteau, Cédric; Gerhards, Daniel; Terrat, Sebastien; Dequiedt, Samuel; Alexandre, Hervé; Guilloux-Benatier, Michèle; von Wallbrunn, Christian; Rousseaux, Sandrine

    2016-02-01

    The efficiency of the FT-IR technique for studying the inter- and intra biodiversity of cultivable non-Saccharomyces yeasts (NS) present in different must samples was examined. In first, the capacity of the technique FT-IR to study the global diversity of a given sample was compared to the pyrosequencing method, used as a reference technique. Seven different genera (Aureobasidium, Candida, Cryptococcus, Hanseniaspora, Issatchenkia, Metschnikowia and Pichia) were identified by FT-IR and also by pyrosequencing. Thirty-eight other genera were identified by pyrosequencing, but together they represented less than 6% of the average total population of 6 musts. Among the species identified, some of them present organoleptic potentials in winemaking, particularly Starmerella bacillaris (synonym Candidazemplinina). So in a second time, we evaluated the capacity of the FT-IR technique to discriminate the isolates of this species because few techniques were able to study intraspecific NS yeast biodiversity. The results obtained were validated by using a classic method as ITS sequencing. Biodiversity at strain level was high: 19 different strains were identified from 58 isolates. So, FT-IR spectroscopy seems to be an accurate and reliable method for identifying major genera present in the musts. The two biggest advantages of the FT-IR are the capacity to characterize intraspecific biodiversity of non-Saccharomyces yeasts and the possibility to discriminate a lot of strains.

  10. Characterization of large amyloid fibers and tapes with Fourier transform infrared (FT-IR) and Raman spectroscopy.

    Science.gov (United States)

    Ridgley, Devin M; Claunch, Elizabeth C; Barone, Justin R

    2013-12-01

    Amyloids are self-assembled protein structures implicated in a host of neurodegenerative diseases. Organisms can also produce "functional amyloids" to perpetuate life, and these materials serve as models for robust biomaterials. Amyloids are typically studied using fluorescent dyes, Fourier transform infrared (FT-IR), or Raman spectroscopy analysis of the protein amide I region, and X-ray diffraction (XRD) because the self-assembled β-sheet secondary structure of the amyloid can be easily identified with these techniques. Here, FT-IR and Raman spectroscopy analyses are described to characterize amyloid structures beyond just identification of the β-sheet structure. It has been shown that peptide mixtures can self-assemble into nanometer-sized amyloid structures that then continue to self-assemble to the micrometer scale. The resulting structures are flat tapes of low rigidity or cylinders of high rigidity depending on the peptides in the mixture. By monitoring the aggregation of peptides in solution using FT-IR spectroscopy, it is possible to identify specific amino acids implicated in β-sheet formation and higher order self-assembly. It is also possible to predict the final tape or cylinder morphology and gain insight into the structure's physical properties based on observed intermolecular interactions during the self-assembly process. Tapes and cylinders are shown to both have a similar core self-assembled β-sheet structure. Soft tapes also have weak hydrophobic interactions between alanine, isoleucine, leucine, and valine that facilitate self-assembly. Rigid cylinders have similar hydrophobic interactions that facilitate self-assembly and also have extensive hydrogen bonding between glutamines. Raman spectroscopy performed on the dried tapes and fibers shows the persistence of these interactions. The spectroscopic analyses described could be generalized to other self-assembling amyloid systems to explain property and morphological differences.

  11. The Assesment of the Decayed Lime Wood Polymeric Components by TG and FT-IR Parameters Correlation

    Directory of Open Access Journals (Sweden)

    Paula BUGHEANU

    2010-12-01

    Full Text Available The restoration and conservation practices of wooden artifacts increasingly need more nondestructive, inexpensive and no-time consuming diagnosis methods. A number of twelve samples of lime wood in various states of degradation from furniture and panel painting were investigated by thermal analysis and infrared spectroscopy. The present work was undertaken to quantify the degree of complementarity of the TG and FT-IR methods by assessing >the ration between cellulose, hemicelluloses and lignin of the decayed lime wood by the correlation of the parameters RTG = ΔmHC /ΔmL from TGA data, and R1FTIR = Aab1370/Aab1505, R2FTIR = Abz1370/Abz1505, R3 FTIR = Iab1370/Iab1505, R4FTIR = Ibz1370/Ibz1505 , from the corresponding peaks of cellulose and hemicelluloses at ~ 1370 cm-1 and of lignin at 1505 cm-1 in FT-IR spectra, where RTG is the ratio between the mass loss of cellulose & hemicelluloses ΔmHC and the mass loss of lignin ΔmL; R1FTIR, R2FTIR, are the ratio between the absolute peaks area Aab1370/Aab1505, and the normalized peaks area Abz1370/Abz1505, respectively, while R3FTIR, R4FTIR are the ratio between the absolute peaks intensity Iab1370/Iab1505, and the normalized peaks intensity Ibz1370/Ibz1505, respectively. We found that the TG parameter decreases in the same order as FT-IR parameters R1 FTIR, R2FTIR, R3FTIR, R4FTIR, and relates well in the values with R1FTIR.

  12. Monitoring biochemical changes in bacterial spore during thermal and pressure-assisted thermal processing using FT-IR spectroscopy.

    Science.gov (United States)

    Subramanian, Anand; Ahn, Juhee; Balasubramaniam, V M; Rodriguez-Saona, Luis

    2007-10-31

    Pressure-assisted thermal processing (PATP) is being widely investigated for processing low acid foods. However, its microbial safety has not been well established and the mechanism of inactivation of pathogens and spores is not well understood. Fourier transform infrared (FT-IR) spectroscopy was used to study some of the biochemical changes in bacterial spores occurring during PATP and thermal processing (TP). Spore suspensions (approximately 10(9) CFU/mL of water) of Clostridium tyrobutyricum, Bacillus sphaericus, and three strains of Bacillus amyloliquefaciens were treated by PATP (121 degrees C and 700 MPa) for 0, 10, 20, and 30 s and TP (121 degrees C) for 0, 10, 20, and 30 s. Treated and untreated spore suspensions were analyzed using FT-IR in the mid-infrared region (4000-800 cm(-1)). Multivariate classification models based on soft independent modeling of class analogy (SIMCA) were developed using second derivative-transformed spectra. The spores could be differentiated up to the strain level due to differences in their biochemical composition, especially dipicolinic acid (DPA) and secondary structure of proteins. During PATP changes in alpha-helix and beta-sheets of secondary protein were evident in the spectral regions 1655 and 1626 cm(-1), respectively. Infrared absorption bands from DPA (1281, 1378, 1440, and 1568 cm(-1)) decreased significantly during the initial stages of PATP, indicating release of DPA. During TP changes were evident in the bands associated with secondary proteins. DPA bands showed little or no change during TP. A correlation was found between the spore's Ca-DPA content and its resistance to PATP. FT-IR spectroscopy could classify different strains of bacterial spores and determine some of the changes occurring during spore inactivation by PATP and TP. Furthermore, this technique shows great promise for rapid screening PATP-resistant bacterial spores.

  13. Application of spectroscopic methods (FT-IR, Raman, ECD and NMR) in studies of identification and optical purity of radezolid

    Science.gov (United States)

    Michalska, Katarzyna; Gruba, Ewa; Mizera, Mikołaj; Lewandowska, Kornelia; Bednarek, Elżbieta; Bocian, Wojciech; Cielecka-Piontek, Judyta

    2017-08-01

    In the presented study, N-{[(5S)-3-(2-fluoro-4‧-{[(1H-1,2,3-triazol-5-ylmethyl)amino]methyl}biphenyl-4-yl)-2-oxo-1,3-oxazolidin-5-yl]methyl}acetamide (radezolid) was synthesized and characterized using FT-IR, Raman, ECD and NMR. The aim of this work was to assess the possibility of applying classical spectral methods such as FT-IR, Raman, ECD and NMR spectroscopy for studies on the identification and optical purity of radezolid. The experimental interpretation of FT-IR and Raman spectra of radezolid was conducted in combination with theoretical studies. Density functional theory (DFT) with the B3LYP hybrid functional was used for obtaining radezolid spectra. Full identification was carried out by COSY, 1H {13C} HSQC and 1H {13C} HMBC experiments. The experimental NMR chemical shifts and spin-spin coupling constants were compared with theoretical calculations using the DFT method and B3LYP functional employing the 6-311 ++G(d,p) basis set and the solvent polarizable continuum model (PCM). The experimental ECD spectra of synthesized radezolid were compared with experimental spectra of the reference standard of radezolid. Theoretical calculations enabled us to conduct HOMO and LUMO analysis and molecular electrostatic potential maps were used to determine the active sites of microbiologically active form of radezolid enantiomer. The relationship between results of ab initio calculations and knowledge about chemical-biological properties of S-radezolid and other oxazolidinone derivatives are also discussed.

  14. ATR-FT-IR spectral collection of conservation materials in the extended region of 4000-80 cm⁻¹.

    Science.gov (United States)

    Vahur, Signe; Teearu, Anu; Peets, Pilleriin; Joosu, Lauri; Leito, Ivo

    2016-05-01

    In this paper, a spectral collection of over 150 ATR-FT-IR spectra of materials related to cultural heritage and conservation science has been presented that have been measured in the extended region of 4000-80 cm(-1) (mid-IR and far-IR region). The applicability of the spectra and, in particular, the extended spectral range, for investigation of art-related materials is demonstrated on a case study. This collection of ATRFT-IR reference spectra is freely available online (http://tera.chem.ut.ee/IR_spectra/) and is meant to be a useful tool for researchers in the field of conservation and materials science.

  15. High-pressure FT IR measurements of crystalline methylene chloride up to 120 kbar in the diamond anvil cell

    Science.gov (United States)

    Shimizu, H.; Xu, J.; Mao, H. K.; Bell, P. M.

    1984-03-01

    The FT IR spectra of pressure-induced crystalline CH 2Cl 2 at room temperature were measured at hydrostatic pressures up to 120 kbar in the diamond anvil cell. The pressure dependences of the internal modes (ν 3, ν 9, ν 8, and ν 2) are reported and compared with the result of Raman scattering measurements. The discontinuity of the slope (dν/d P) at ≈ 45 kbar for the ν 9 antisymmetric CCl streching mode indicates the pressure-induced second-order phase transition which seems to be triggered by the interaction between the ν 9 mode and the ν 3 symmetric CCl stretching mode.

  16. Retrieving CO concentrations from FT-IR spectra with nonmodeled interferences and fluctuating baselines using PCR model parameters

    DEFF Research Database (Denmark)

    Bak, J.

    2001-01-01

    are subtracted one by one from the contaminated spectrum, and the length of the spectral contour within specified wavenumbers is then calculated. When the length of the contour is at a minimum, a condition is reached where the pure component part of the measured spectrum is absent and only the background signal......-factor PCR models based on pure gaseous 1 and 4 cm(-1) CO Fourier transform infrared (FT-IR) spectra (50-400 ppm) measured at ambient temperatures. The program is validated with measured CO spectra containing interferents such as N2O, CO2, and added Hitran-simulated H2O, CO2, and COS spectra, representing...

  17. FT-IR reflection spectra of single crystals: resolving phonons of different symmetry without using polarised radiation

    OpenAIRE

    METODIJA NAJDOSKI; VLADIMIR IVANOVSKI; VLADIMIR M. PETRUSEVSKI

    2000-01-01

    Fourier-transform infrared (FT-IR) reflection spectra, asquired at nearnormal incidence, were recorded from single crystals belonging to six crystal systems: CsCr(SO4)2.12H2O (alum, cubic), K2CuCl2·2H2O (Mitscherlichite, tetragonal), CaCO3 (calcite, hexagonal), KHSO4 (mercallite, orthorhombic), CaSO4·2H2O (gypsum, monoclinic) and CuSO4·5H2O (chalcantite, triclinic). The acquired IR reflection spectra were further transformed into absorption spectra, employing the Kramers-Kronig transformation...

  18. The use of FT-IR as a screening technique for organic residue analysis of archaeological samples

    Science.gov (United States)

    Shillito, Lisa M.; Almond, Matthew J.; Wicks, Karen; Marshall, Lisa-Jane R.; Matthews, Wendy

    2009-02-01

    A range of archaeological samples have been examined using FT-IR spectroscopy. These include suspected coprolite samples from the Neolithic site of Çatalhöyük in Turkey, pottery samples from the Roman site of Silchester, UK and the Bronze Age site of Gatas, Spain and unidentified black residues on pottery sherds from the Roman sites of Springhead and Cambourne, UK. For coprolite samples the aim of FT-IR analysis is identification. Identification of coprolites in the field is based on their distinct orange colour; however, such visual identifications can often be misleading due to their similarity with deposits such as ochre and clay. For pottery the aim is to screen those samples that might contain high levels of organic residues which would be suitable for GC-MS analysis. The experiments have shown coprolites to have distinctive spectra, containing strong peaks from calcite, phosphate and quartz; the presence of phosphorus may be confirmed by SEM-EDX analysis. Pottery containing organic residues of plant and animal origin has also been shown to generally display strong phosphate peaks. FT-IR has distinguished between organic resin and non-organic compositions for the black residues, with differences also being seen between organic samples that have the same physical appearance. Further analysis by GC-MS has confirmed the identification of the coprolites through the presence of coprostanol and bile acids, and shows that the majority of organic pottery residues are either fatty acids or mono- or di-acylglycerols from foodstuffs, or triterpenoid resin compounds exposed to high temperatures. One suspected resin sample was shown to contain no organic residues, and it is seen that resin samples with similar physical appearances have different chemical compositions. FT-IR is proposed as a quick and cheap method of screening archaeological samples before subjecting them to the more expensive and time-consuming method of GC-MS. This will eliminate inorganic samples such

  19. Avaliação do uso de técnicas PIR-G/FT-IR para caracterização de elastômeros Evaluation of PIR-G/FT-IR techniques for characterization of elastomers

    Directory of Open Access Journals (Sweden)

    Natália B. Sanches

    2006-01-01

    Full Text Available A técnica de pirólise gasosa, em bico de Bunsen, para análise por espectroscopia no infravermelho com transformada de Fourier (PIR-G/FT-IR foi aplicada a diferentes borrachas, incluindo algumas misturas. Foi observado que é possível diferenciar os tipos de elastômeros por meio de análise de produtos gasosos de pirólise, inclusive aqueles que apresentam espectros IR de pirolisados líquidos similares, como é o caso de CIIR e BIIR, NR/SBR e EPDM/SBR, SBR/BR e SBR.Pyrolysis and infrared spectroscopy (PIR-G/FT-IR were used for investigating gaseous products of rubber. The results show that this method was suitable to identify different elastomers and elastomer blends, including rubbers that present similar IR spectra of pyrolysed liquid products such as CIIR and BIIR, NR/SBR and EPDM/SBR, SBR/BR and SBR.

  20. Structural investigations on some cadmium-borotellurate glasses using ultrasonic, FT-IR and X-ray techniques

    Energy Technology Data Exchange (ETDEWEB)

    Gaafar, M.S., E-mail: m.gaafar@mu.edu.sa [Physics Department, College of Sciences, Majmaah University (Saudi Arabia); Ultrasonic Laboratory, National Institute for Standards, Tersa Str., P.O. Box 136, El-Haram, El-Giza 12211 (Egypt); Shaarany, I. [Physics Department, College of Sciences, Majmaah University (Saudi Arabia); Physics Department, Faculty of Science, Suez Canal University, Ismailia (Egypt); Alharbi, T. [Physics Department, College of Sciences, Majmaah University (Saudi Arabia)

    2014-12-15

    Highlights: • 50B{sub 2}O{sub 3}–(50 – x)TeO{sub 2}–xCdO glass system has been prepared by melt quenching technique. • Both sound velocities decrease with increase in x. • Studies on the structure of these glasses, have revealed that Cd{sup 2+} ions are incorporated in the form of CdO{sub 6}. - Abstract: Glasses in the system 50B{sub 2}O{sub 3}–(50 − x)TeO{sub 2}–xCdO with different CdO contents (0, 10, 20, 30, 40 and 50 mol%), have been prepared by melt quenching technique. Elastic properties, X-ray and FT-IR spectroscopic studies have been employed to study the role of CdO on the structure of the investigated glass system. Elastic properties and Debye temperature have been investigated using sound wave velocity measurements at 4 MHz at room temperature. The results showed that the density increase and the molar volume decrease while both sound velocities decrease with increase in x. Elastic properties, FT-IR and X-ray diffraction studies on the network structure of these glass structures, have revealed that Cd{sup 2+} ions are incorporated in the form of CdO{sub 6}, decreasing the molar volume and compensate for the decrease in the average coordination number of tellurium atoms which was the reason for the increase in elastic moduli.

  1. FT-IR and Micro-Raman spectroscopic studies of archaeological potteries recently excavated in Poompuhar, Tamilnadu, India

    Science.gov (United States)

    Kiruba, S.; Ganesan, S.

    2015-06-01

    Ancient ceramics are the abundant artifacts that give the knowledge of the past societies. Therefore it is of great importance to acquire knowledge about the chemical composition of the clay in archaeological artifacts. The spectroscopic techniques represent one of the most powerful tools to investigate the structure of all the materials and chemical composition of the cultural object like potteries. An attempt has been made in the present work to estimate the firing temperature of the archaeological pottery shreds excavated from the archaeological site Poompuhar in the state of Tamilnadu in India. The firing temperature of the archaeological pottery shreds were estimated by recording the corresponding FT-IR spectra in the range 4000-450 cm-1 and Micro Raman spectra in the range 1800-400 cm-1. The clay mineral present in the pottery samples are identified through FT-IR method and was confirmed with Micro Raman spectroscopy as both are complement to each other. The major primary mineral present in the samples is Kaolinite and the secondary mineral present is quartz and the accessory minerals present in the samples are hematite, magnetite and feldspar. The results of Raman spectra showed that the potters of this site used a mixture of clays as raw materials. The firing temperature for some of the samples did not exceed 800 °C which suggests the use of open fire.

  2. FT-IR evaluation of SmFeAsO1-xFx (x = 0, 0.069)

    Science.gov (United States)

    Shinohara, Hajime; Kamihara, Yoichi

    2012-02-01

    Optical properties of superconducting SmFeAsO1-xFx (x=0, 0.069) were demonstrated by reflection measurement with FT- IR method. Polycrystalline SmFeAsO1-xFx samples were synthesized using two-step solid state reaction described elsewhere [New J. Phys.12, 033005 (2010)]. Purity of samples was checked by X-ray diffraction patterns using Cu K- alpha radiation. The reflection measurement was performed at the range from 9000 cm-1 to 18000 cm-1 that was corresponded to an energy region from 1.12 eV to 2.25 eV. A photoconductivity of SmFeAsO1-xFx was determined by Kramer-Kroning (KK) relation. Reflectivity and photoconductivity measurements, as well as by FT-IR, at various areas were performed to define an energy level of materials [EPL, 84 67013 (2008), and J. Phys. Soc. Jpn. 80 013707 (2011)]. Obtained photoconductivity and reflection spectra were similar to those of LaFeAsO1-xFx that was a basic compound of LnFeAsO1-xFx (Ln=La, Ce, Sm), reported by Z. G. Chen et al [Phys. Rev. B 81, 100502 (2010)]. Our result suggests that the energy band structure of SmFeAsO was affected by F-doping even in visible area. Details and temperature dependence of the reflection and photoconductivity spectra will be presented at the conference.

  3. Sensing the structural differences in cellulose from apple and bacterial cell wall materials by Raman and FT-IR spectroscopy.

    Science.gov (United States)

    Szymańska-Chargot, Monika; Cybulska, Justyna; Zdunek, Artur

    2011-01-01

    Raman and Fourier Transform Infrared (FT-IR) spectroscopy was used for assessment of structural differences of celluloses of various origins. Investigated celluloses were: bacterial celluloses cultured in presence of pectin and/or xyloglucan, as well as commercial celluloses and cellulose extracted from apple parenchyma. FT-IR spectra were used to estimate of the I(β) content, whereas Raman spectra were used to evaluate the degree of crystallinity of the cellulose. The crystallinity index (X(C)(RAMAN)%) varied from -25% for apple cellulose to 53% for microcrystalline commercial cellulose. Considering bacterial cellulose, addition of xyloglucan has an impact on the percentage content of cellulose I(β). However, addition of only xyloglucan or only pectins to pure bacterial cellulose both resulted in a slight decrease of crystallinity. However, culturing bacterial cellulose in the presence of mixtures of xyloglucan and pectins results in an increase of crystallinity. The results confirmed that the higher degree of crystallinity, the broader the peak around 913 cm(-1). Among all bacterial celluloses the bacterial cellulose cultured in presence of xyloglucan and pectin (BCPX) has the most similar structure to those observed in natural primary cell walls.

  4. Accelerated Aging of BKC 44306-10 Rigid Polyurethane Foam: FT-IR Spectroscopy, Dimensional Analysis, and Micro Computed Tomography

    Energy Technology Data Exchange (ETDEWEB)

    Gilbertson, Robert D. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Patterson, Brian M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Smith, Zachary [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-01-02

    An accelerated aging study of BKC 44306-10 rigid polyurethane foam was carried out. Foam samples were aged in a nitrogen atmosphere at three different temperatures: 50 °C, 65 °C, and 80 °C. Foam samples were periodically removed from the aging canisters at 1, 3, 6, 9, 12, and 15 month intervals when FT-IR spectroscopy, dimensional analysis, and mechanical testing experiments were performed. Micro Computed Tomography imaging was also employed to study the morphology of the foams. Over the course of the aging study the foams the decreased in size by a magnitude of 0.001 inches per inch of foam. Micro CT showed the heterogeneous nature of the foam structure likely resulting from flow effects during the molding process. The effect of aging on the compression and tensile strength of the foam was minor and no cause for concern. FT-IR spectroscopy was used to follow the foam chemistry. However, it was difficult to draw definitive conclusions about the changes in chemical nature of the materials due to large variability throughout the samples.

  5. Sensing the Structural Differences in Cellulose from Apple and Bacterial Cell Wall Materials by Raman and FT-IR Spectroscopy

    Directory of Open Access Journals (Sweden)

    Artur Zdunek

    2011-05-01

    Full Text Available Raman and Fourier Transform Infrared (FT-IR spectroscopy was used for assessment of structural differences of celluloses of various origins. Investigated celluloses were: bacterial celluloses cultured in presence of pectin and/or xyloglucan, as well as commercial celluloses and cellulose extracted from apple parenchyma. FT-IR spectra were used to estimate of the Iβ content, whereas Raman spectra were used to evaluate the degree of crystallinity of the cellulose. The crystallinity index (XCRAMAN% varied from −25% for apple cellulose to 53% for microcrystalline commercial cellulose. Considering bacterial cellulose, addition of xyloglucan has an impact on the percentage content of cellulose Iβ. However, addition of only xyloglucan or only pectins to pure bacterial cellulose both resulted in a slight decrease of crystallinity. However, culturing bacterial cellulose in the presence of mixtures of xyloglucan and pectins results in an increase of crystallinity. The results confirmed that the higher degree of crystallinity, the broader the peak around 913 cm−1. Among all bacterial celluloses the bacterial cellulose cultured in presence of xyloglucan and pectin (BCPX has the most similar structure to those observed in natural primary cell walls.

  6. ATR-FT-IR spectroscopy in the region of 550-230 cm -1 for identification of inorganic pigments

    Science.gov (United States)

    Vahur, Signe; Teearu, Anu; Leito, Ivo

    2010-03-01

    A comprehensive study of ATR-FT-IR spectra of 40 inorganic pigments of different colours widely used in historical paintings has been carried out in the low wave number spectral range (550-230 cm -1). The infrared spectra were recorded from mixtures of pigment and linseed oil. It is demonstrated that this spectral range - essentially devoid of absorption peaks of the common binder materials - can be well used for identification of inorganic pigments in paint samples thereby markedly extending the possibilities of pigment identification/confirmation by ATR-IR spectroscopy into the realm of pigments having no absorptions in the mid-IR region. In some cases the method can be used alone for pigment identification and in many cases it provides useful additional evidence for pigment identification using other instrumental techniques (electron microprobe analysis, XRF, optical microscopy). Together with earlier work this study provides a comprehensive overview of the pigment identification possibilities using ATR-FT-IR as well as a collection of reference spectra and is expected to be a useful reference for conservation practitioners.

  7. ATR FT-IR spectroscopy on Vmh2 hydrophobin self-assembled layers for Teflon membrane bio-functionalization

    Energy Technology Data Exchange (ETDEWEB)

    Portaccio, M., E-mail: marianna.portaccio@unina2.it [Dipartimento di Medicina Sperimentale – Seconda Università di Napoli, Via S.M. di Costantinopoli, 16-80134 Napoli (Italy); Gravagnuolo, A.M., E-mail: alfredomaria.gravagnuolo@unina.it [Dipartimento di Scienze Chimiche, Università “Federico II”, Via Cintia, 21- 80126 Napoli (Italy); Longobardi, S., E-mail: sara.longobardi@unina.it [Dipartimento di Scienze Chimiche, Università “Federico II”, Via Cintia, 21- 80126 Napoli (Italy); Giardina, P., E-mail: paola.giardina@unina.it [Dipartimento di Scienze Chimiche, Università “Federico II”, Via Cintia, 21- 80126 Napoli (Italy); Rea, I., E-mail: ilaria.rea@na.imm.cnr.it [Institute for Microelectronics and Microsystems, CNR, Via P. Castellino, 111-80131 Napoli (Italy); De Stefano, L., E-mail: luca.destefano@na.imm.cnr.it [Institute for Microelectronics and Microsystems, CNR, Via P. Castellino, 111-80131 Napoli (Italy); Cammarota, M., E-mail: marcella.cammarota@unina2.it [Dipartimento di Medicina Sperimentale – Seconda Università di Napoli, Via S.M. di Costantinopoli, 16-80134 Napoli (Italy); Lepore, M., E-mail: maria.lepore@unina2.it [Dipartimento di Medicina Sperimentale – Seconda Università di Napoli, Via S.M. di Costantinopoli, 16-80134 Napoli (Italy)

    2015-10-01

    Graphical abstract: - Highlights: • Hydrophobin self-assembled layers on Teflon in different preparation conditions were investigated. • ATR collection data geometry allowed samples examination without any particular preparation. • Amide content, lipid/amide and carbohydrate/amide ratios of the protein layer were estimated. • Secondary structure of protein was determined for the examined samples. • FT-IR demonstrated to be of extreme relevance in monitoring hydrophobin self-assembled layers preparation. - Abstract: Surface functionalization by layers of hydrophobins, amphiphilic proteins produced by fungi offers a promising and green strategy for fabrication of biomedical and bioanalytical devices. The layering process of the Vmh2 hydrophobin from Pleurotus ostreatus on Teflon membrane has been investigated by Attenuated Total Reflection Fourier Transform Infrared (ATR FT-IR) spectroscopy. In particular, protein layers obtained with hydrophobin purified with two different procedures and in various coating conditions have been examined. The layers have been characterized by quantifying the amide I and amide II band area together with the lipid/amide ratio and carbohydrate/amide ratio. This characterization can be very useful in evaluating the best purification strategy and coating conditions. Moreover the analysis of the secondary structure of the layered protein using the deconvolution procedure of amide I band indicate the prevalent contribution from β-sheet state. The results inferred by infrared spectroscopy have been also confirmed by scanning electron microscopy imaging.

  8. Identification and Quantification of Microplastics in Wastewater Using Focal Plane Array-Based Reflectance Micro-FT-IR Imaging.

    Science.gov (United States)

    Tagg, Alexander S; Sapp, Melanie; Harrison, Jesse P; Ojeda, Jesús J

    2015-06-16

    Microplastics (microplastics in these matrices has not been investigated. Although efficient methods for the analysis of microplastics in sediment samples and marine organisms have been published, no methods have been developed for detecting these pollutants within organic-rich wastewater samples. In addition, there is no standardized method for analyzing microplastics isolated from environmental samples. In many cases, part of the identification protocol relies on visual selection before analysis, which is open to bias. In order to address this, a new method for the analysis of microplastics in wastewater was developed. A pretreatment step using 30% hydrogen peroxide (H2O2) was employed to remove biogenic material, and focal plane array (FPA)-based reflectance micro-Fourier-transform (FT-IR) imaging was shown to successfully image and identify different microplastic types (polyethylene, polypropylene, nylon-6, polyvinyl chloride, polystyrene). Microplastic-spiked wastewater samples were used to validate the methodology, resulting in a robust protocol which was nonselective and reproducible (the overall success identification rate was 98.33%). The use of FPA-based micro-FT-IR spectroscopy also provides a considerable reduction in analysis time compared with previous methods, since samples that could take several days to be mapped using a single-element detector can now be imaged in less than 9 h (circular filter with a diameter of 47 mm). This method for identifying and quantifying microplastics in wastewater is likely to provide an essential tool for further research into the pathways by which microplastics enter the environment.

  9. FT-IR Method for the Quantification of Isoflavonol Glycosides in Nutritional Supplements of Soy (Glycine max (L.) MERR.).

    Science.gov (United States)

    Mulsow, Katharina; Eidenschink, Juliane; Melzig, Matthias F

    2015-01-01

    Due to increasing health consciousness, a lot of food supplements are sold and used. Dietary supplements of Glycine max (L.) MERR. are used as an alternative treatment for menopausal complaints such as hot flashes. Thereby, the effective soy compounds are the isoflavones daidzin, genistin, and glycitin. However, only the total soy extract content of the nutritional supplements is indicated. The aim of this study is to introduce a fast, efficient, and economic Fourier transformation infrared (FT-IR) spectroscopy method to quantify the active ingredients in the complex matrix of soy-based supplements. Five different nutritional supplements of Glycine max (L.) MERR. were purchased from a German pharmacy and were extracted with 80% aqueous methanol. A high-performance liquid chromatography (HPLC) method was used for the separation. The samples were concentrated and measured with infrared spectroscopy. An FT-IR method was established to quantify the active ingredients in the complex matrix of soy-based nutritional supplements. The partial least-squares algorithm was used to develop the method, which enabled the estimation of the content of particular isoflavones (daidzin R(2) = 0.86, glycitin R(2) = 0.94, genistin R(2) = 0.96) and the quantification of the total isoflavone content (R(2) = 0.92) despite peak overlap in the infrared (IR) spectra. The method for the quantification of the isoflavonol glycosides is precise with the standard error of prediction being 13.54%.

  10. FT-Raman and FT-IR studies of 1:2.5 piroxicam: β-cyclodextrin inclusion compound

    Science.gov (United States)

    Bertoluzza, A.; Rossi, M.; Taddei, P.; Redenti, E.; Zanol, M.; Ventura, P.

    1999-05-01

    The FT-Raman and FT-IR spectra of amorphous 1:2.5 piroxicam (P): β-cyclodextrin (βCD) inclusion compound (PβCD) are presented and discussed in comparison with the spectra of the three main modifications of piroxicam (α,β and monohydrate). In the 1700-1200 cm -1 FT-Raman spectrum of 1:2.5 PβCD inclusion compound the bands of βCD are weak and covered by those stronger of piroxicam, differently from the FT-IR spectrum where the bands of βCD are stronger, so covering a large part of the spectrum. Typical FT-Raman marker bands are assigned for the characterization of the three modifications of piroxicam. The FT-Raman spectrum of 1:2.5 PβCD inclusion compound predominantly shows the bands at about 1465 and 1400 cm -1 of the monohydrate, indicating that piroxicam assumes the zwitterionic structure stabilized by interaction with βCD via electrostatic and hydrogen bonds. The dipolar character of 1:2.5 PβCD inclusion compound improves the solubility and the dissolution rate of piroxicam and thus its rate of absorption.

  11. Discrimination of five species of Fritillaria and its extracts by FT-IR and 2D-IR

    Science.gov (United States)

    Li, Dan; Jin, Zhexiong; Zhou, Qun; Chen, Jianbo; Lei, Yu; Sun, Suqin

    2010-06-01

    Bulbus Fritillariae (in Chinese named Beimu), referred to the bulbs of several Fritillaria species ( Liliaceae), is a commonly used anti-tussive and expectorant herb in traditional Chinese medicine (TCM) for more than 2000 years. The objective of this study is to discriminate five species of Beimu herbs and their total alkaloid extracts by Fourier transform infrared spectroscopy (FT-IR), second derivative infrared spectroscopy, and two-dimensional correlation infrared spectroscopy (2D-IR) under thermal perturbation. The structural information of the samples indicated that, Beimu and their extract residues contain a large amount of starch, since some characteristic absorption peaks of the starch, such as 1158, 1080, 1015 and 987 cm -1 can be observed. Further more, the characteristic absorption peaks of the sulfate which arouse at 1120 ± 5 and 618 cm -1 in the IR spectra of Beimu aqueous extracts can be find. This validated that people used the sulfur fumigation method in the processing. The macroscopical fingerprint characters of FT-IR and 2D-IR spectra can not only provide the information of main chemical constituents in medicinal materials and their different extracts, but also compare the components differences among the similar samples. In conclusion, the multi-steps IR macro-fingerprint method is rapid, effective, visual and accurate for pharmaceutical research.

  12. The effect of arsenic exposure on the biochemical and mineral contents of Labeo rohita bones: An FT-IR study

    Science.gov (United States)

    Palaniappan, PL. RM.; Vijayasundaram, V.

    2009-01-01

    Arsenic compounds are ubiquitous and widespread in the environment as a result of natural or anthropogenic occurrence. Fish are the major source of protein for human consumption. They are also a source of contamination, because of the amounts of heavy elements they can contain, some of which are highly toxic. Fish bones are high in calcium, which is an essential mineral for normal body function. It consists of water, organic material, and mineral matter. Chelating agents have been used clinically as antidotes for acute and chronic metal intoxications. In the present study, an attempt is made to investigate the bio-accumulation of arsenic and its effect on the biochemical and mineral contents of Labeo rohita bones using, Fourier transform infrared (FT-IR) spectroscopy. The results of the present study indicate that arsenic exposure induces significant reduction on the biochemical and mineral contents of the L. rohita bones. Further, the DMSA treatment significantly improves these levels. This shows that DMSA is an effective chelator for arsenic toxicity. Quantitative curve-fitting analyses of amide I band have proved useful in studying the nature and the extent of protein conformational changes. A decrease in α-helical and random coil structures and an increase in β-sheet structures have been observed due to arsenic exposure. In conclusion, the present study shows that the FT-IR spectroscopy coupled with second derivative and curve-fitting analysis gives useful information about the biochemical and mineral contents of the L. rohita bones.

  13. Traceability of Boletaceae Mushrooms Using Data Fusion of UV-vis and FT-IR Combined with Chemometrics Methods.

    Science.gov (United States)

    Yao, Sen; Li, Tao; Liu, HongGao; Li, JieQing; Wang, YuanZhong

    2017-09-30

    Boletaceae mushrooms are wild-grown edible mushrooms which have high nutrition, delicious flavor and large economic value distributing in Yunnan Province, China. Traceability is important for the authentication and quality assessment of Boletaceae mushrooms. In this study, ultraviolet visible (UV-vis) and Fourier transform infrared (FT-IR) spectroscopies were applied for traceability of 247 Boletaceae mushroom samples in combination with chemometrics. Compared with single spectroscopy technique, data fusion strategy can obviously improve the classification performance in PLS-DA and GS-SVM models, both species and geographical origins traceabilities. In addition, PLS-DA and GS-SVM models can provide 100.00% accuracy for species traceability, and have reliable evaluation parameters. For geographical origins traceability, the accuracy of prediction in PLS-DA model by data fusion was just 64.63%, but the GS-SVM model based on data fusion was 100.00%. The results demonstrated that data fusion strategy of UV-vis and FT-IR combined with GS-SVM could provide the higher synergic effect for traceability of Boletaceae mushrooms and have a good generalization ability for the comprehensive quality control and evaluation of similar food. This article is protected by copyright. All rights reserved.

  14. Quantum-chemical, NMR, FT IR, and ESI MS studies of complexes of colchicine with Zn(II).

    Science.gov (United States)

    Jankowski, Wojciech; Kurek, Joanna; Barczyński, Piotr; Hoffmann, Marcin

    2017-04-01

    Colchicine is a tropolone alkaloid from Colchicinum autumnale. It shows antifibrotic, antimitotic, and anti-inflammatory activities, and is used to treat gout and Mediterranean fever. In this work, complexes of colchicine with zinc(II) nitrate were synthesized and investigated using DFT, (1)H and (13)C NMR, FT IR, and ESI MS. The counterpoise-corrected and uncorrected interaction energies of these complexes were calculated. We also calculated their (1)H, (13)C NMR, and IR spectra and compared them with the corresponding experimentally obtained data. According to the ESI MS mass spectra, colchicine forms stable complexes with zinc(II) nitrate that have various stoichiometries: 2:1, 1:1:1, and 2:1:1 with respect to colchichine, Zn(II), and nitrate ion. All of the complexes were investigated using the quantum theory of atoms in molecules (QTAIM). The calculated and the measured spectra showed differences before and after the complexation process. Calculated electron densities and bond critical points indicated the presence of bonds between the ligands and the central cation in the investigated complexes that satisfied the quantum theory of atoms in molecules. Graphical Abstract DFT, NMR, FT IR, ESI MS, QTAIM and puckering studies of complexes of colchicine with Zn(II).

  15. FT-IR and thermoluminescence investigation of P2O5-BaO-K2O glass system

    Science.gov (United States)

    Ivascu, C.; Timar-Gabor, A.; Cozar, O.

    2013-11-01

    The 0.5P2O5ṡxBaOṡ(0.5-x)K2O glass system (0≤x≤0.5mol%) is investigated by FT-IR and thermoluminescence as a possible dosimetic material. FT-IR spectra show structural network modifications with the composition variations of the studied glasses. The predominant absorption bands are characterized by two broad peaks near 500 cm-1, two weak peaks around 740 cm-1 and three peaks in the 900-1270 cm-1 region. The shift in the position of the band assigned to asymmetric stretching of PO2- group, υas(PO2-) modes from ˜1100 cm-1 to 1085 cm-1 and the decrease in its relative intensity with the increasing of K2O content shows a network modifier role of this oxide.. Luminescence investigations show that by adding modifier oxides in the phosphate glass a dose dependent TL signals result upon irradiation. Thus P2O5-BaO-K2O glass system is a possible candidate material for dosimetry in the dose 0 - 50 Gy range.

  16. A four class model for digital breast histopathology using high-definition Fourier transform infrared (FT-IR) spectroscopic imaging

    Science.gov (United States)

    Mittal, Shachi; Wrobel, Tomasz P.; Leslie, L. S.; Kadjacsy-Balla, Andre; Bhargava, Rohit

    2016-03-01

    High-definition (HD) Fourier transform infrared (FT-IR) spectroscopic imaging is an emerging technique that not only enables chemistry-based visualization of tissue constituents, and label free extraction of biochemical information but its higher spatial detail makes it a potentially useful platform to conduct digital pathology. This methodology, along with fast and efficient data analysis, can enable both quantitative and automated pathology. Here we demonstrate a combination of HD FT-IR spectroscopic imaging of breast tissue microarrays (TMAs) with data analysis algorithms to perform histologic analysis. The samples comprise four tissue states, namely hyperplasia, dysplasia, cancerous and normal. We identify various cell types which would act as biomarkers for breast cancer detection and differentiate between them using statistical pattern recognition tools i.e. Random Forest (RF) and Bayesian algorithms. Feature optimization is integrally carried out for the RF algorithm, reducing computation time as well as redundant spectral features. We achieved an order of magnitude reduction in the number of features with comparable prediction accuracy to that of the original feature set. Together, the demonstration of histology and selection of features paves the way for future applications in more complex models and rapid data acquisition.

  17. X-ray (Radial Distribution Function, RDF) and FT-IR analysis of high sulphur Tirap (India) coal

    Energy Technology Data Exchange (ETDEWEB)

    Saikia, B.K.; Boruah, R.K.; Gogoi, P.K. [North East Institute of Science & Technology CSIR, Jorhat (India)

    2009-06-15

    A preliminary study has been performed on high sulphur coals from Tirap colliery of Assam, India, using X-ray (RDF) technique and FT-IR spectroscopy. XRD pattern of the coal shows that it is amorphous in nature. Function of radial distribution analysis (FRDA) indicates that coal is lignite in type and there is no evidence of graphite like structures. The first maximum in the FRDA at R=0.133 nm relates to the C-C aliphatic bond (type C-CH=CH-C), and the second maximum at R=0.25 nm relates to the distance between carbon atoms of aliphatic chains that are located across one carbon atom. The curve intensity profiles obtained from FRDA show quite regular molecular packets for this coal. FT-IR study shows the presence of aliphatic -CH, -CH{sub 2} and -CH{sub 3} groups, aliphatic C-O-C stretching associated with -OH and -NH stretching vibrations and HCC rocking (single and condensed rings).

  18. Caracterização por FT-IR de agentes de cura utilizados em resinas epoxídicas-II-polimercaptana, poliaminoamida e amina modificada

    Directory of Open Access Journals (Sweden)

    Romão Benedita M. V.

    2003-01-01

    Full Text Available Amostras de resina epoxídica (EP curadas com compostos à base depolimercaptana (SH, SH na presença de poliamino amida, e amina modificada, constituindo, respectivamente, os sistemas epoxídicos (SE 1, 2 e 3, foram preparadas segundo condições estabelecidas pelas curvas de calorimetria exploratória diferencial (DSC de EP e agentes de cura, ou endurecedores (AC e analisadas, antes e após preparação do SE, por espectroscopia no infravermelho com transformada de Fourier (FT-IR por meio de técnicas de transmissão (pastilha de KBr, pirólise por bico de Bunsen, e pirólisecontrolada (CONTROLPIR/FT-IR dentro da faixa de temperatura fornecida pela análise termogravimétrica (TG dos SE 1, 2 e 3, para a caracterização de cada AC. Para tal fim, as absorções FT-IR do pirolisado líquido obtido pela metodologia CONTROLPIR/FT-IR foram avaliadas, em comparação ao espectro do AC de referência. A caracterização dos agentes de cura foi feita com a técnica TG/FT-IR do gás liberado de cada SE, em comparação ao espectro de referência do produto de degradação do respectivo AC.

  19. Attenuated total reflectance FT-IR imaging and quantitative energy dispersive-electron probe X-ray microanalysis techniques for single particle analysis of atmospheric aerosol particles.

    Science.gov (United States)

    Ryu, JiYeon; Ro, Chul-Un

    2009-08-15

    This work demonstrates the practical applicability of the combined use of attenuated total reflectance (ATR) FT-IR imaging and low-Z particle electron probe X-ray microanalysis (EPMA) techniques for the characterization of individual aerosol particles. These two single particle analytical techniques provide complementary information on the physicochemical characteristics of the same individual particles, that is, the low-Z particle EPMA for the information on the morphology and elemental concentration and the ATR-FT-IR imaging on the functional group, molecular species, and crystal structure. It was confirmed that the ATR-FT-IR imaging technique can provide sufficient FT-IR absorption signals to perform molecular speciation of individual particles of micrometer size when applied to artificially generated aerosol particles such as ascorbic acid and NaNO(3) aerosols. An exemplar indoor atmospheric aerosol sample was investigated to demonstrate the practical feasibility of the combined application of ATR-FT-IR imaging and low-Z particle EPMA techniques for the characterization of individual airborne particles.

  20. Vibrational (FT-IR, Raman) and DFT analysis on the structure of labile drugs. The case of crystalline tebipenem and its ester

    Science.gov (United States)

    Paczkowska, Magdalena; Mizera, Mikołaj; Dzitko, Jakub; Lewandowska, Kornelia; Zalewski, Przemysław; Cielecka-Piontek, Judyta

    2017-04-01

    A tebipenem is active form of the first, oral carbapenem antibiotic - tebipenem pivoxyl. The optimized conformations of tebipenem pivoxyl and tebipenem were determinated by quantum-chemical calculations performed with the use of B3LYP functional and 6-31G(d,p) as a basis set. For the most stable conformations of tebipenem and its ester were established theoretical Raman and FT-IR spectra. The theoretical approach in significant part was support for identification of experimental Raman (400-4000 cm-1) and FT-IR (100-4000 cm-1) of tebipenem and tebipenem pivoxil. The geometric structure of molecules, HOMO and LUMO orbitals and molecular electrostatic potential were also determined. The benefits of applying FT-IR and Raman scattering spectroscopy for characterization of tebipenem and its ester consisted in demonstrating differences in their spectral properties.

  1. Ion Association in Hydrothermal Sodium Sulfate Solutions Studied by Modulated FT-IR-Raman Spectroscopy and Molecular Dynamics.

    Science.gov (United States)

    Reimer, Joachim; Steele-MacInnis, Matthew; Wambach, Jörg M; Vogel, Frédéric

    2015-07-30

    Saline aqueous solutions at elevated pressures and temperatures play an important role in processes such as supercritical water oxidation (SCWO) and supercritical water gasification (SCWG), as well as in natural geochemical processes in Earth and planetary interiors. Some solutions exhibit a negative temperature coefficient of solubility at high temperatures, thereby leading to salt precipitation with increasing temperature. Using modulated FT-IR Raman spectroscopy and classical molecular dynamics simulations (MD), we studied the solute speciation in solutions of 10 wt % Na2SO4, at conditions close to the saturation limit. Our experiments reveal that ion pairing and cluster formation are favored as solid saturation is approached, and ionic clusters form prior to the precipitation of solid sulfate. The proportion of such clusters increases as the phase boundary is approached either by decreasing pressure or by increasing temperature in the vicinity of the three-phase (vapor-liquid-solid) curve.

  2. Differentiation of Body Fluid Stains on Fabrics Using External Reflection Fourier Transform Infrared Spectroscopy (FT-IR) and Chemometrics.

    Science.gov (United States)

    Zapata, Félix; de la Ossa, Ma Ángeles Fernández; García-Ruiz, Carmen

    2016-04-01

    Body fluids are evidence of great forensic interest due to the DNA extracted from them, which allows genetic identification of people. This study focuses on the discrimination among semen, vaginal fluid, and urine stains (main fluids in sexual crimes) placed on different colored cotton fabrics by external reflection Fourier transform infrared spectroscopy (FT-IR) combined with chemometrics. Semen-vaginal fluid mixtures and potential false positive substances commonly found in daily life such as soaps, milk, juices, and lotions were also studied. Results demonstrated that the IR spectral signature obtained for each body fluid allowed its identification and the correct classification of unknown stains by means of principal component analysis (PCA) and soft independent modeling of class analogy (SIMCA). Interestingly, results proved that these IR spectra did not show any bands due to the color of the fabric and no substance of those present in daily life which were analyzed, provided a false positive.

  3. NIR FT-Raman microspectroscopy of fluid inclusions: Comparisons with VIS Raman and FT-IR microspectroscopies

    Energy Technology Data Exchange (ETDEWEB)

    Pironon, J.; Dubessy, J. (CREGU and GDR CNRS-CREGU, Vandoeuvre-les-Nancy (France)); Sawatzki, J. (BRUKER Analytische Messtechnik Gmbh, Karlsruhe (Germany))

    1991-12-01

    The first Raman spectra of hydrocarbon inclusions using Fourier transform (FT) Raman microspectroscopy were obtained with a 1,064 nm laser excitation in the near-infrared range (NIR FT-Raman). Some inclusions reveal the typical CH vibrational bands of organic compounds, but most of the inclusions that are fluorescent during visible Raman microspectroscopy (514 nm excitation) are still fluorescent in the NIR range. These Raman spectra are presented and compared to the conventional visible (VIS) Raman and FT-IR spectra. For spectra obtained on the same nonfluorescent inclusion, the signal/background ratio is lower in NIR FT-Raman than in VIS Raman. This ratio should be improved by application of more sensitive detectors. The increase of the power density (laser power/impact laser area) could be a future improvement in the limit of thermal background excitation and pyrolysis of the oils trapped in inclusions.

  4. ATR-FT-IR spectroscopy in the region of 500-230 cm -1 for identification of inorganic red pigments

    Science.gov (United States)

    Vahur, Signe; Knuutinen, Ulla; Leito, Ivo

    2009-08-01

    It is demonstrated that micro-ATR-FT-IR in the low wave number range (500-230 cm -1) can be well used for identification of pigments in paint samples thereby markedly extending the possibilities of pigment identification by ATR-IR spectroscopy into the realm of pigments having no absorptions in the mid-IR region. Reference spectra of pigments can be conveniently obtained by mixing them with linseed oil in approximately 1:1 mass ratio. Vermilion (or cinnabar), read lead, different red iron oxide pigments and cadmium red can be identified. In some cases the method can be used alone for pigment identification and in many cases it provides useful additional evidence for pigment identification using other instrumental techniques (electron microprobe analysis, XRF, optical microscopy).

  5. FT-IR spectroscopy assessment of aesthetic dental materials irradiated with low-dose therapeutic ionizing radiation

    Science.gov (United States)

    Cruz, A. D.; Almeida, S. M.; Rastelli, A. N. S.; Bagnato, V. S.; Byscolo, F. N.

    2009-03-01

    The aim of the present study was to evaluate the effects of low-dose therapeutic ionizing radiation on different aesthetic dental materials. Forty five specimens ( n = 45) of three different aesthetic restorative materials were prepared and randomly divided into five groups: G1 (control group); G2, G3, G4, G5 experimental groups irradiated respectively with 0.25, 0.50, 0.75, and 1.00 Gy of gamma radiation by the 60Co teletherapy machine. Chemical analyses were performed using a FT-IR Nicolet 520 spectrophotometer with reflectance diffuse technique. Even a minimal exposition at ionizing radiation in therapeutic doses can provide chemical changes on light-cured composite resins. The three studied restorative materials showed changes after exposure at gamma radiation, however the increase of the radiation dose did not contribute to an increase in this effect.

  6. THE SULFONATION STUDY OF REACTION MECHANISM ON PAPAVERINE ALKALOID BY GC-MS AND FT-IR

    Directory of Open Access Journals (Sweden)

    I Made Sudarma

    2010-06-01

    Full Text Available The aim of this research was to prove theoretical mechanism reaction on the sulfonation of papaverine alkaloid and the result could be used as a reference on the transformation of these alkaloid to the other derivatives. Theoriticaly sulfonation of papaverine (1 by HO-SO2Cl could produced papaverine sulfonyl chloride (1a. The formation of this product was analyzed by analytical thin layer chromatography GC-MS, and FT-IR. These analysis showed the formation of product (1a more favorable than the other. Tlc showed product (1a less polar than papaverine, and supported by GC-MS and infrared which showed molecular ion at m/z 412 due to the presence of -SO2Cl and vibration at 1153,4 dan 1265,2 Cm-1 due to absorption of sulfonyl group.   Keywords: reaction mechanism, sulfonation, papaverine alkaloid.

  7. Spectroscopic (FT-IR, FT-Raman, UV-Visible) and quantum chemical studies of 4-Chloro-3-iodobenzophenone

    Science.gov (United States)

    Venkata Prasad, K.; Muthu, S.; Santhamma, C.

    2017-01-01

    The vibrational analysis of the substituted Benzophenone molecule 4-Chloro-3-iodobenzophenone (4, 3-ClIBP) is carried out using both FT-IR and FT-Raman spectra and also quantum chemical calculations of the scaled frequencies using the DFT method B3LYP/LanL2DZ basis set. The natural bond orbital analysis of this molecule has been carried out to describe the various intramolecular interactions responsible for the stabilization of the molecule. The HOMO, LUMO energy gap have been computed with the TD-DFT theory and the differences are compared with UV-absorption spectra. The statistical thermodynamic functions are calculated for the range of 100-1000 k. The Fukui functions are evaluated to describe the activity of the sites.

  8. Solid state 13C NMR and FT-IR spectroscopy of the cocoon silk of two common spiders

    Science.gov (United States)

    Bramanti, Emilia; Catalano, Donata; Forte, Claudia; Giovanneschi, Mario; Masetti, Massimo; Veracini, Carlo Alberto

    2005-11-01

    The structure of the silk from cocoons of two common spiders, Araneus diadematus (family Araneidae) and Achaearanea tepidariorum (family Theridiidae) was investigated by means of 13C solid state NMR and FT-IR spectroscopies. The combined use of these two techniques allowed us to highlight differences in the two samples. The cocoon silk of Achaearanea tepidariorum is essentially constituted by helical and β-sheet structures, whereas that of Araneus diadematus shows a more complex structure, containing also β-strands and β-turns. Moreover, the former silk is essentially crystalline while the latter contains more mobile domains. The structural differences of the two cocoon silks are ascribed to the different habitat of the two species.

  9. Alkali metal salts of rutin - Synthesis, spectroscopic (FT-IR, FT-Raman, UV-VIS), antioxidant and antimicrobial studies.

    Science.gov (United States)

    Samsonowicz, M; Kamińska, I; Kalinowska, M; Lewandowski, W

    2015-12-05

    In this work several metal salts of rutin with lithium, sodium, potassium, rubidium and cesium were synthesized. Their molecular structures were discussed on the basis of spectroscopic (FT-IR, FT-Raman, UV-VIS) studies. Optimized geometrical structure of rutin was calculated by B3LYP/6-311++G(∗∗) method and sodium salt of rutin were calculated by B3LYP/LanL2DZ method. Metal chelation change the biological properties of ligand therefore the antioxidant (FRAP and DPPH) and antimicrobial activities (toward Escherichia coli, Staphylococcus aureus, Enterococcus faecium, Proteus vulgaris, Pseudomonas aeruginosa, Klebsiella pneumonia, Candida albicans and Saccharomyces cerevisiae) of alkali metal salts were evaluated and compared with the biological properties of rutin.

  10. Spectroscopic (FT-IR, FT-Raman, UV) and microbiological studies of di-substituted benzoates of alkali metals

    Science.gov (United States)

    Kalinowska, M.; Świsłocka, R.; Borawska, M.; Piekut, J.; Lewandowski, W.

    2008-06-01

    The FT-IR, FT-Raman and UV spectra of 3,5-dihydroxybenzoic and 3,5-dichlorobenzoic acids as well as lithium, sodium, potassium, rubidium, caesium 3,5-dihydroxy- and 3,5-dichlorobenzoates were recorded, assigned and compared. The theoretical geometries, Mulliken atomic charges, IR wavenumbers were obtained in B3LYP/6-311++G** level. On the basis of the gathered experimental and theoretical data the effect of metals and substituents on the electronic system of studied compounds were investigated. Moreover, the antimicrobiological activity of studied compounds against two species of bacteria: Bacillus subtilis, Staphylococus aureus and one species of yeast: Candida albicans were studied after 24 and 48 h of incubation. The attempt was made, to find out whether there is any correlation between the first principal component and the degree of growth inhibition exhibited by studied compounds in relation to selected microorganisms.

  11. In vivo skin leptin modulation after 14 MeV neutron irradiation: a molecular and FT-IR spectroscopic study

    Energy Technology Data Exchange (ETDEWEB)

    Cestelli Guidi, M.; Mirri, C.; Marcelli, A. [Laboratori Nazionali di Frascati - INFN, Frascati, Rome (Italy); Fratini, E.; Amendola, R. [ENEA, UT BIORAD-RAB, Rome (Italy); Licursi, V.; Negri, R. [Universita La Sapienza, Dip. Biologia e Biotecnologie ' ' Charles Darwin' ' , Rome (Italy)

    2012-09-15

    This paper discusses gene expression changes in the skin of mice treated by monoenergetic 14 MeV neutron irradiation and the possibility of monitoring the resultant lipid depletion (cross-validated by functional genomic analysis) as a marker of radiation exposure by high-resolution FT-IR (Fourier transform infrared) imaging spectroscopy. The irradiation was performed at the ENEA Frascati Neutron Generator (FNG), which is specifically dedicated to biological samples. FNG is a linear electrostatic accelerator that produces up to 1.0 x 10{sup 11} 14-MeV neutrons per second via the D-T nuclear reaction. The functional genomic approach was applied to four animals for each experimental condition (unirradiated, 0.2 Gy irradiation, or 1 Gy irradiation) 6 hours or 24 hours after exposure. Coregulation of a subclass of keratin and keratin-associated protein genes that are physically clustered in the mouse genome and functionally related to skin and hair follicle proliferation and differentiation was observed. Most of these genes are transiently upregulated at 6 h after the delivery of the lower dose delivered, and drastically downregulated at 24 h after the delivery of the dose of 1 Gy. In contrast, the gene coding for the leptin protein was consistently upregulated upon irradiation with both doses. Leptin is a key protein that regulates lipid accumulation in tissues, and its absence provokes obesity. The tissue analysis was performed by monitoring the accumulation and the distribution of skin lipids using FT-IR imaging spectroscopy. The overall picture indicates the differential modulation of key genes during epidermis homeostasis that leads to the activation of a self-renewal process at low doses of irradiation. (orig.)

  12. ATR-FT/IR study on the interactions between gliadins and dextrin and their effects on protein secondary structure.

    Science.gov (United States)

    Secundo, Francesco; Guerrieri, Nicoletta

    2005-03-09

    The effects of heat treatment and dextrin addition on the secondary structure of gliadins were investigated by means of attenuated total reflection Fourier transform infrared spectroscopy (ATR-FT/IR). Gliadins and gliadin/dextrin mixtures (before and after thermal treatment) were prepared as a dried protein film on the ATR-FT/IR zinc selenide cell plate and equilibrated at a water activity (a(w)) of 0.06. The results show that gliadins undergo conformational changes upon thermal treatment both in the absence and in the presence of dextrin. In particular, in the thermally treated gliadins, the decrease of the band at around 1651 cm(-)(1) and the increase of the bands at around 1628 and 1690 cm(-)(1) suggest a loss of alpha-helix structure and a higher content of protein aggregates. The same trend was observed in the presence of dextrin. Concerning the interactions between gliadins and dextrin, gliadin/dextrin mixtures show variations in the amide I region compared to native gliadins (e.g., an increase of the band at 1645 cm(-)(1) and the absence of the band at around 1668 cm(-)(1)) that might be due to hydrogen bond formation between gliadins and dextrin. It was also found that the spectrum of gliadin/dextrin mixtures was less affected by the hydration state than that of native gliadins, as observed from the differential spectra obtained by subtraction of the spectrum obtained at a(w) = 0.06 (driest condition tested) from the spectrum of the sample equilibrated at a(w) = 0.84. This could be due to the fact that C=O and N-H groups of gliadins are engaged to form hydrogen bonds with the hydroxyl groups of dextrin, and so they are not perturbed by the presence of water molecules. Finally, water activity effects on the secondary structure of gliadins are also discussed.

  13. Application of FT-IR spectroscopy for control of the medium composition during the biodegradation of nitro aromatic compounds.

    Science.gov (United States)

    Grube, Mara; Muter, Olga; Strikauska, Silvija; Gavare, Marita; Limane, Baiba

    2008-11-01

    Previous studies showed that cabbage leaf extract (CLE) added to the growth medium can noticeably promote the degradation of nitro aromatic compounds by specific consortium of bacteria upon their growth. For further development of the approach for contaminated soil remediation it was necessary to evaluate the qualitative and/or quantitative composition of different origin CLE and their relevance on the growth of explosives-degrading bacteria. Six CLE (different by species, cultivars and harvesting time) were tested and used as additives to the growth medium. It was shown that nitro aromatic compounds can be identified in the FT-IR absorption spectra by the characteristic band at 1,527 cm(-1), and in CLE by the characteristic band at 1,602 cm(-1). The intensity of the CLE band at 1,602 cm(-1) correlated with the concentration of total nitrogen (R2=0.87) and decreased upon the growth of bacteria. The content of nitrogen in CLE differed (0.22-1.00 vol.%) and significantly influenced the content of total carbohydrates (9.50-16.00% DW) and lipids [3.90-9.90% dry weight (DW)] accumulated in bacterial cells while the content of proteins was similar in all samples. Though this study showed quantitative differences in the composition of the studied CLE and the response of bacterial cells to the composition of the growth media, and proved the potential of this additive for remediation of contaminated soil. It was shown that analysis of CLE and monitoring of the conversion of nitro aromatic compounds can be investigated by FT-IR spectroscopy as well as by conventional chemical methods.

  14. FT-IR-cPAS—New Photoacoustic Measurement Technique for Analysis of Hot Gases: A Case Study on VOCs

    Science.gov (United States)

    Hirschmann, Christian Bernd; Koivikko, Niina Susanna; Raittila, Jussi; Tenhunen, Jussi; Ojala, Satu; Rahkamaa-Tolonen, Katariina; Marbach, Ralf; Hirschmann, Sarah; Keiski, Riitta Liisa

    2011-01-01

    This article describes a new photoacoustic FT-IR system capable of operating at elevated temperatures. The key hardware component is an optical-readout cantilever microphone that can work up to 200 °C. All parts in contact with the sample gas were put into a heated oven, incl. the photoacoustic cell. The sensitivity of the built photoacoustic system was tested by measuring 18 different VOCs. At 100 ppm gas concentration, the univariate signal to noise ratios (1σ, measurement time 25.5 min, at highest peak, optical resolution 8 cm−1) of the spectra varied from minimally 19 for o-xylene up to 329 for butyl acetate. The sensitivity can be improved by multivariate analyses over broad wavelength ranges, which effectively co-adds the univariate sensitivities achievable at individual wavelengths. The multivariate limit of detection (3σ, 8.5 min, full useful wavelength range), i.e., the best possible inverse analytical sensitivity achievable at optimum calibration, was calculated using the SBC method and varied from 2.60 ppm for dichloromethane to 0.33 ppm for butyl acetate. Depending on the shape of the spectra, which often only contain a few sharp peaks, the multivariate analysis improved the analytical sensitivity by 2.2 to 9.2 times compared to the univariate case. Selectivity and multi component ability were tested by a SBC calibration including 5 VOCs and water. The average cross selectivities turned out to be less than 2% and the resulting inverse analytical sensitivities of the 5 interfering VOCs was increased by maximum factor of 2.2 compared to the single component sensitivities. Water subtraction using SBC gave the true analyte concentration with a variation coefficient of 3%, although the sample spectra (methyl ethyl ketone, 200 ppm) contained water from 1,400 to 100k ppm and for subtraction only one water spectra (10k ppm) was used. The developed device shows significant improvement to the current state-of-the-art measurement methods used in industrial

  15. FT-IR-cPAS—New Photoacoustic Measurement Technique for Analysis of Hot Gases: A Case Study on VOCs

    Directory of Open Access Journals (Sweden)

    Riitta Liisa Keiski

    2011-05-01

    Full Text Available This article describes a new photoacoustic FT-IR system capable of operating at elevated temperatures. The key hardware component is an optical-readout cantilever microphone that can work up to 200 °C. All parts in contact with the sample gas were put into a heated oven, incl. the photoacoustic cell. The sensitivity of the built photoacoustic system was tested by measuring 18 different VOCs. At 100 ppm gas concentration, the univariate signal to noise ratios (1σ, measurement time 25.5 min, at highest peak, optical resolution 8 cm−1 of the spectra varied from minimally 19 for o-xylene up to 329 for butyl acetate. The sensitivity can be improved by multivariate analyses over broad wavelength ranges, which effectively co-adds the univariate sensitivities achievable at individual wavelengths. The multivariate limit of detection (3σ, 8.5 min, full useful wavelength range, i.e., the best possible inverse analytical sensitivity achievable at optimum calibration, was calculated using the SBC method and varied from 2.60 ppm for dichloromethane to 0.33 ppm for butyl acetate. Depending on the shape of the spectra, which often only contain a few sharp peaks, the multivariate analysis improved the analytical sensitivity by 2.2 to 9.2 times compared to the univariate case. Selectivity and multi component ability were tested by a SBC calibration including 5 VOCs and water. The average cross selectivities turned out to be less than 2% and the resulting inverse analytical sensitivities of the 5 interfering VOCs was increased by maximum factor of 2.2 compared to the single component sensitivities. Water subtraction using SBC gave the true analyte concentration with a variation coefficient of 3%, although the sample spectra (methyl ethyl ketone, 200 ppm contained water from 1,400 to 100k ppm and for subtraction only one water spectra (10k ppm was used. The developed device shows significant improvement to the current state-of-the-art measurement methods used

  16. Rapid, nondestructive estimation of surface polymer layer thickness using attenuated total reflection fourier transform infrared (ATR FT-IR) spectroscopy and synthetic spectra derived from optical principles.

    Science.gov (United States)

    Weinstock, B André; Guiney, Linda M; Loose, Christopher

    2012-11-01

    We have developed a rapid, nondestructive analytical method that estimates the thickness of a surface polymer layer with high precision but unknown accuracy using a single attenuated total reflection Fourier transform infrared (ATR FT-IR) measurement. Because the method is rapid, nondestructive, and requires no sample preparation, it is ideal as a process analytical technique. Prior to implementation, the ATR FT-IR spectrum of the substrate layer pure component and the ATR FT-IR and real refractive index spectra of the surface layer pure component must be known. From these three input spectra a synthetic mid-infrared spectral matrix of surface layers 0 nm to 10,000 nm thick on substrate is created de novo. A minimum statistical distance match between a process sample's ATR FT-IR spectrum and the synthetic spectral matrix provides the thickness of that sample. We show that this method can be used to successfully estimate the thickness of polysulfobetaine surface modification, a hydrated polymeric surface layer covalently bonded onto a polyetherurethane substrate. A database of 1850 sample spectra was examined. Spectrochemical matrix-effect unknowns, such as the nonuniform and molecularly novel polysulfobetaine-polyetherurethane interface, were found to be minimal. A partial least squares regression analysis of the database spectra versus their thicknesses as calculated by the method described yielded an estimate of precision of ±52 nm.

  17. Combining FT-IR spectroscopy and multivariate analysis for qualitative and quantitative analysis of the cell wall composition changes during apples development.

    Science.gov (United States)

    Szymanska-Chargot, M; Chylinska, M; Kruk, B; Zdunek, A

    2015-01-22

    The aim of this work was to quantitatively and qualitatively determine the composition of the cell wall material from apples during development by means of Fourier transform infrared (FT-IR) spectroscopy. The FT-IR region of 1500-800 cm(-1), containing characteristic bands for galacturonic acid, hemicellulose and cellulose, was examined using principal component analysis (PCA), k-means clustering and partial least squares (PLS). The samples were differentiated by development stage and cultivar using PCA and k-means clustering. PLS calibration models for galacturonic acid, hemicellulose and cellulose content from FT-IR spectra were developed and validated with the reference data. PLS models were tested using the root-mean-square errors of cross-validation for contents of galacturonic acid, hemicellulose and cellulose which was 8.30 mg/g, 4.08% and 1.74%, respectively. It was proven that FT-IR spectroscopy combined with chemometric methods has potential for fast and reliable determination of the main constituents of fruit cell walls.

  18. A novel FT-IR spectroscopic method based on lipid characteristics for qualitative and quantitative analysis of animal-derived feedstuff adulterated with ruminant ingredients.

    Science.gov (United States)

    Gao, Fei; Zhou, Simiao; Han, Lujia; Yang, Zengling; Liu, Xian

    2017-12-15

    The objective of this study was to explore the ability of Fourier transform infrared (FT-IR) spectroscopy to authenticate adulterated animal-derived feedstuff. A total of 18 raw meat and bone meals (MBMs), including 9 non-ruminant MBMs and 9 ruminant MBMs, were mixed to obtain 81 binary mixtures with specific proportions (1-35%). Lipid spectral characteristics were analyzed by FT-IR spectroscopy combined with chemometrics. Changes in FT-IR spectra were observed as adulterant concentration was varied. The results illustrate ruminant adulteration can be successfully distinguished based on lipid characteristics. PLS model was established to quantify ruminant adulteration, which was shown to be valid (R(2)P>0.90). Furthermore, the ratios of CC/CO and CC/CH(CH2), as well as the number of CH(CH2) in the fatty acids of adulterated lipids, were calculated, which showed that differences in the trans fatty acid content and the degree of unsaturation were the main contributors to determination of adulteration based on FT-IR spectroscopy. Copyright © 2017. Published by Elsevier Ltd.

  19. FT-IR and micro-Raman spectroscopic study of decorated potteries from VI and VII century BC, excavated in ancient Ainos Turkey

    Science.gov (United States)

    Akyuz, S.; Akyuz, T.; Basaran, S.; Bolcal, C.; Gulec, A.

    2007-05-01

    Ancient decorated pottery fragments belong to sixth and seventh century BC, excavated in the archaeological district of Enez - Turkey (Ancient Ainos) were analysed using micro-Raman and FT-IR spectroscopy. The experimental results allowed us to identify the peculiar components of the ceramic body and the main pigments of the decoration. The presence of albite and anatase suggests low firing temperatures.

  20. Effects of Low Carbohydrate High Protein (LCHP) diet on atherosclerotic plaque phenotype in ApoE/LDLR-/- mice: FT-IR and Raman imaging.

    Science.gov (United States)

    Wrobel, T P; Marzec, K M; Chlopicki, S; Maślak, E; Jasztal, A; Franczyk-Żarów, M; Czyżyńska-Cichoń, I; Moszkowski, T; Kostogrys, R B; Baranska, M

    2015-09-22

    Low Carbohydrate High Protein (LCHP) diet displays pro-atherogenic effects, however, the exact mechanisms involved are still unclear. Here, with the use of vibrational imaging, such as Fourier transform infrared (FT-IR) and Raman (RS) spectroscopies, we characterize biochemical content of plaques in Brachiocephalic Arteries (BCA) from ApoE/LDLR(-/-) mice fed LCHP diet as compared to control, recomended by American Institute of Nutrition, AIN diet. FT-IR images were taken from 6-10 sections of BCA from each mice and were complemented with RS measurements with higher spatial resolution of chosen areas of plaque sections. In aortic plaques from LCHP fed ApoE/LDLR(-/-) mice, the content of cholesterol and cholesterol esters was increased, while that of proteins was decreased as evidenced by global FT-IR analysis. High resolution imaging by RS identified necrotic core/foam cells, lipids (including cholesterol crystals), calcium mineralization and fibrous cap. The decreased relative thickness of the outer fibrous cap and the presence of buried caps were prominent features of the plaques in ApoE/LDLR(-/-) mice fed LCHP diet. In conclusion, FT-IR and Raman-based imaging provided a complementary insight into the biochemical composition of the plaque suggesting that LCHP diet increased plaque cholesterol and cholesterol esters contents of atherosclerotic plaque, supporting the cholesterol-driven pathogenesis of LCHP-induced atherogenesis.

  1. Risk assessment of an old landfill regarding the potential of gaseous emissions--a case study based on bioindication, FT-IR spectroscopy and thermal analysis.

    Science.gov (United States)

    Tintner, Johannes; Smidt, Ena; Böhm, Katharina; Matiasch, Lydia

    2012-12-01

    Risk assessment of two sections (I and II) of an old landfill (ALH) in Styria (Austria) in terms of reactivity of waste organic matter and the related potential of gaseous emissions was performed using conventional parameters and innovative tools to verify their effectiveness in practice. The ecological survey of the established vegetation at the landfill surface (plant sociological relevés) indicated no relevant emissions over a longer period of time. Statistical evaluation of conventional parameters reveals that dissolved organic carbon (DOC), respiration activity (RA(4)), loss of ignition (LOI) and total inorganic carbon (TIC) mostly influence the variability of the gas generation sum (GS(21)). According to Fourier Transform Infrared (FT-IR) spectral data and the results of the classification model the reactivity potential of the investigated sections is very low which is in accordance with the results of plant sociological relevés and biological tests. The interpretation of specific regions in the FT-IR spectra was changed and adapted to material characteristics. Contrary to mechanically-biologically treated (MBT) materials, where strong aliphatic methylene bands indicate reactivity, they are rather assigned to the C-H vibrations of plastics in old landfill materials. This assumption was confirmed by thermal analysis and the characteristic heat flow profile of plastics containing landfill samples. Therefore organic carbon contents are relatively high compared to other stable landfills as shown by a prediction model for TOC contents based on heat flow profiles and partial least squares regression (PLS-R). The stability of the landfill samples, expressed by the relation of CO(2) release and enthalpies, was compared to unreactive landfills, archeological samples, earthlike materials and hardly degradable organic matter. Due to the material composition and the aging process the landfill samples are located between hardly degradable, but easily combustible

  2. FT-IR, Laser-Raman spectra and computational analysis of 5-Methyl-3-phenylisoxazole-4-carboxylic acid

    Science.gov (United States)

    Sert, Yusuf; Mahendra, M.; Keskinoğlu, S.; Chandra; Srikantamurthy, N.; Umesha, K. B.; Çırak, Ç.

    2015-03-01

    In this study the experimental and theoretical vibrational frequencies of a newly synthesized anti-tumor, antiviral, hypoglycemic, antifungal and anti-HIV agent namely, 5-Methyl-3-phenylisoxazole-4-carboxylic acid has been investigated. The experimental FT-IR (4000-400 cm-1) and Laser-Raman spectra (4000-100 cm-1) of the molecule in solid phase have been recorded. The theoretical vibrational frequencies and optimized geometric parameters (bond lengths, bond angles and torsion angles) have been calculated by using density functional theory (DFT/B3LYP: Becke, 3-parameter, Lee-Yang-Parr and DFT/M06-2X: highly parametrized, empirical exchange correlation function) with 6-311++G(d,p) basis set by Gaussian 09W software, for the first time. The assignments of the vibrational frequencies have been done by potential energy distribution (PED) analysis by using VEDA 4 software. The theoretical optimized geometric parameters and vibrational frequencies have been found to be in good agreement with the corresponding experimental data and results in the literature. In addition, the highest occupied molecular orbital (HOMO) energy, the lowest unoccupied molecular orbital (LUMO) energy and the other related molecular energy values of the compound have been investigated by using the same theoretical calculations.

  3. A Study on the Surface Structures of Viscose-based Activated Carbon Fiber by FT-IR Spectroscopy and XPS

    Institute of Scientific and Technical Information of China (English)

    黄强; 黄永秋; 潘鼎

    2004-01-01

    Using viscose fiber (VF) as starting material and common steam as activating agent, formation of oxygen structures in activated carbon fiber is investigated. In the preparation of samples, VF was first heated at temperatures between 450℃ and 900℃ in N2 artmosphere. Then, in a successive activation stage, the product carbonized at 600℃ was activated in steam at 450 - 900℃ for 30 min, and at 600℃for 5- 30 min. The other carbonization products were activated at 600 and 900℃ for 30 min respectively. The products activated at 900℃ were then activated at 450℃ for 30 min again. The starting material, carbonized products and all activation products were examined by FT-IR spectroscopy and some products were examined by X-ray photoelectron spectroscope (XPS). And the yields of the carbonized and activated products were calculated. By analysing these spectra, the amount of oxygen-containing functional groups of the activated products attained under various activation time, various activation temperature and various previous carbonization temperature was determined.

  4. Ft-Ir Spectroscopic Analysis of Potsherds Excavated from the First Settlement Layer of Kuriki Mound, Turkey

    Science.gov (United States)

    Bayazit, Murat; Isik, Iskender; Cereci, Sedat; Issi, Ali; Genc, Elif

    The region covering Southeastern Anatolia takes place in upper Mesopotamia, so it has numerous cultural heritages due to its witness to various social movements of different civilizations in ancient times. Kuruki Mound is located on the junction point of Tigris River and Batman Creek, near Oymatas village which is almost 15 km to Batman, Turkey. The mound is dated back to Late Chalcolithic. Archaeological excavations are carried out on two hills named as “Kuriki Mound-1” and “Kuriki Mound-2” in which 4-layer and 2-layer settlements have been revealed, respectively. This region will be left under the water by the reservoir lake of Ilısu Dam when its construction is completed. Thus, characterization of ancient materials such as potsherds, metals and skeleton ruins should be rapidly done. In this study, 12 potsherds excavated from Layer-1 (the first settlement layer after the surface) in Kuriki Mound-2 were investigated by FT-IR spectrometry. Energy dispersive X-ray fluorescence (EDXRF) and X-ray diffraction (XRD) analyses were used as complementary techniques in order to expose chemical and mineralogical/phase contents, respectively. Obtained results showed that the potteries have been produced with calcareous clays and they include moderate amounts of MgO, K2O, Na2O and Fe2O3 in this context. Additionally, high temperature phases have also been detected with XRD analyses in some samples.

  5. Single cell synchrotron FT-IR microspectroscopy reveals a link between neutral lipid and storage carbohydrate fluxes in S. cerevisiae.

    Directory of Open Access Journals (Sweden)

    Frédéric Jamme

    Full Text Available In most organisms, storage lipids are packaged into specialized structures called lipid droplets. These contain a core of neutral lipids surrounded by a monolayer of phospholipids, and various proteins which vary depending on the species. Hydrophobic structural proteins stabilize the interface between the lipid core and aqueous cellular environment (perilipin family of proteins, apolipoproteins, oleosins. We developed a genetic approach using heterologous expression in Saccharomyces cerevisiae of the Arabidopsis thaliana lipid droplet oleosin and caleosin proteins AtOle1 and AtClo1. These transformed yeasts overaccumulate lipid droplets, leading to a specific increase in storage lipids. The phenotype of these cells was explored using synchrotron FT-IR microspectroscopy to investigate the dynamics of lipid storage and cellular carbon fluxes reflected as changes in spectral fingerprints. Multivariate statistical analysis of the data showed a clear effect on storage carbohydrates and more specifically, a decrease in glycogen in our modified strains. These observations were confirmed by biochemical quantification of the storage carbohydrates glycogen and trehalose. Our results demonstrate that neutral lipid and storage carbohydrate fluxes are tightly connected and co-regulated.

  6. Biosorption of Lead and Copper by Heavy Metal Resistance Bacterium using Fourier Transform Infrared Spectrophotometer (FT IR

    Directory of Open Access Journals (Sweden)

    This paper should be cited as: Mohseni M, Khosravi F, Mohadjerani M, Chaichi, MJ . [ Biosorption of Lead and Copper by Heavy Metal Resistance Bacterium using Fourier Transform Infrared Spectrophotometer (FT - IR ]. MLJ. 201 4 ; 8 ( 3 : [Article in Persian] Mohseni, M. (PhD

    2014-09-01

    Full Text Available Background and Objectives: Contamination of environment to lead and copper is rising due to human activities. One of the best methods to remove heavy metals from the environment is bacterial remediation. This study aimed to isolate bacteria and investigate the mechanism of lead and copper bioremediation. Material and Methods: Heavy metal resistant bacteria were isolated from contaminated wastewater samples. The isolates with high resistance to lead and copper were selected for further studies and bioremediation was assessed by atomic absorption spectrophotometer. To determine the functional groups to remove metals, FT-IR was employed. In addition, plasmid curing was studied to determine the location of the genes that are resistance to heavy metals. Results: Ten bacterial isolates that are resistance to heavy metals were isolated. Among these, MKH3 with the highest remediation activity removed %90 lead and %92 copper from the growth medium. The absorption mechanism of MKH3 indicated that the functional groups such as carboxyl, amide, carbonyl and hydroxyl were most effective for removal of heavy metals from the growth medium. The results revealed that heavy metal resistant genes may be located on plasmid DNA. Furthermore, molecular identification demonstrated that MKH3 was similar to Enterobacterhormaechei with 98% homology. Conclusion: Bacterium isolated from a contaminated site showed the ability to remove a high amount of lead and copper. Thus, MKH3 could be useful for the bioremediation of heavy metals, particularly lead and copper, from industrial wastewater and contaminated sites.

  7. Analysis of FT-IR spectra of dicyclopentadienyl (bis-substituted cyclopentadienyl) dithiocyano of titanium, zirconium and hafnium.

    Science.gov (United States)

    Zhang, Jianbo; Ye, Peng; Zong, Yueru; Xu, Zhenhua; Chen, Shoushan

    2007-07-01

    The FT-IR spectra of 18 (R-Cp)2M(NCS)2 were measured. The M-Cp, M-NCS (M=Ti, Zr, Hf) and other vibration modes were reasonably assigned. All complexes of (R-Cp)2M(NCS)2 determined in this paper are bonded by N-M, and the absorption of upsilon(s)(M-Cp)(A1) (M=Ti, Zr and Hf) vibration all appear in 365 cm(-1) or so, while upsilon(as)(M-Cp)(B) appear successively around 420, 350 and 320 cm(-1) in order of Ti, Zr and Hf. The influence of the center metal atoms and the substituents on cyclopentadienyl upon the spectra was discussed. It is mainly in far infrared region that center metal atoms influence upon the infrared spectra. The influence of the substituents to cyclopentadienyling upon its vibration is not significant. Only between 1500 and 1480 cm(-1) did a new absorbing peak appear due to the introduction of substituents to activate upsilon(CC) vibration.

  8. Improved Extended Multiplicative Scatter Correction Algorithm Applied in Blood Glucose Noninvasive Measurement with FT-IR Spectroscopy

    Directory of Open Access Journals (Sweden)

    Qingbo Li

    2013-01-01

    Full Text Available In order to improve the predictive accuracy of human blood glucose quantitative analysis model with fourier transform infrared (FT-IR spectroscopy, this paper uses a method named improved extended multiplicative scatter correction (Im-EMSC, which can effectively eliminate the scattering effects caused by human body strong scattering. The principal components of the differential spectra are used instead of the pure spectra of the analytes in this algorithm. Calibrate the unwanted physical characteristic through the shape of the curve of principal components, and extract the original glucose concentration information. Im-EMSC can efficiently remove most of the pathlength difference and baseline shift influences. Firstly, Im-EMSC is used as a preprocessing method, and then partial least squares (PLS regression method is adopted to establish a quantitative analysis model. In this paper, the result of Im-EMSC is compared with those popular scattering correction algorithms of multiplicative scatter correction (MSC and extended multiplicative scatter correction (EMSC preprocessing methods. Experimental results show that the prediction accuracy has been greatly improved with Im-EMSC method, which is helpful for human noninvasive glucose concentration detection technology.

  9. On the Traceability of Commercial Saffron Samples Using 1H-NMR and FT-IR Metabolomics

    Directory of Open Access Journals (Sweden)

    Roberto Consonni

    2016-02-01

    Full Text Available In previous works on authentic samples of saffron of known history (harvest and processing year, storage conditions, and length of time some biomarkers were proposed using both FT-IR and NMR metabolomics regarding the shelf life of the product. This work addresses the difficulties to trace back the “age” of commercial saffron samples of unknown history, sets a limit value above which these products can be considered substandard, and offers a useful tool to combat saffron mislabeling and fraud with low-quality saffron material. Investigations of authentic and commercial saffron samples of different origin and harvest year, which had been stored under controlled conditions for different lengths of time, allowed a clear-cut clustering of samples in two groups according to the storage period irrespectively of the provenience. In this respect, the four-year cut off point proposed in our previous work assisted to trace back the “age” of unknown samples and to check for possible mislabeling practices.

  10. Evaluation of Salmon Adhesion on PET-Metal Interface by ATR, FT-IR, and Raman Spectroscopy

    Directory of Open Access Journals (Sweden)

    E. Zumelzu

    2015-01-01

    Full Text Available The material employed in this study is an ecoefficient, environmentally friendly, chromium (VI-free (noncarcinogenic metal polymer. The originality of the research lies in the study of the effect of new production procedures of salmon on metal packaging with multilayer polyethylene terephthalate (PET polymer coatings. Our hypothesis states that the adhesion of postmortem salmon muscles to the PET polymer coating produces surface and structural changes that affect the functionality and limit the useful life of metal containers, compromising therefore their recycling capacity as ecomaterials. This work is focused on studying the effects of the biochemical changes of postmortem salmon on the PET coating and how muscle degradation favors adhesion to the container. The experimental design considered a series of laboratory tests of containers simulating the conditions of canned salmon, chemical and physical tests of food-contact canning to evaluate the adhesion, and characterization of changes in the multilayer PET polymer by electron microscopy, ATR, FT-IR, and Raman spectroscopy analyses. The analyses determined the effect of heat treatment of containers on the loss of freshness of canned fish and the increased adhesion to the container wall, and the limited capability of the urea treatment to remove salmon muscle from the container for recycling purposes.

  11. Single Cell Synchrotron FT-IR Microspectroscopy Reveals a Link between Neutral Lipid and Storage Carbohydrate Fluxes in S. cerevisiae

    Science.gov (United States)

    Jamme, Frédéric; Vindigni, Jean-David; Méchin, Valérie; Cherifi, Tamazight; Chardot, Thierry; Froissard, Marine

    2013-01-01

    In most organisms, storage lipids are packaged into specialized structures called lipid droplets. These contain a core of neutral lipids surrounded by a monolayer of phospholipids, and various proteins which vary depending on the species. Hydrophobic structural proteins stabilize the interface between the lipid core and aqueous cellular environment (perilipin family of proteins, apolipoproteins, oleosins). We developed a genetic approach using heterologous expression in Saccharomyces cerevisiae of the Arabidopsis thaliana lipid droplet oleosin and caleosin proteins AtOle1 and AtClo1. These transformed yeasts overaccumulate lipid droplets, leading to a specific increase in storage lipids. The phenotype of these cells was explored using synchrotron FT-IR microspectroscopy to investigate the dynamics of lipid storage and cellular carbon fluxes reflected as changes in spectral fingerprints. Multivariate statistical analysis of the data showed a clear effect on storage carbohydrates and more specifically, a decrease in glycogen in our modified strains. These observations were confirmed by biochemical quantification of the storage carbohydrates glycogen and trehalose. Our results demonstrate that neutral lipid and storage carbohydrate fluxes are tightly connected and co-regulated. PMID:24040242

  12. The retrogradation properties of glutinous rice and buckwheat starches as observed with FT-IR, 13C NMR and DSC.

    Science.gov (United States)

    Lian, Xijun; Wang, Changjun; Zhang, Kunsheng; Li, Lin

    2014-03-01

    The experiment was conducted to study the retrogradation properties of glutinous rice and buckwheat starch with wavelengths of maximum absorbance, FT-IR, (13)C NMR, and DSC. The results show that the starches in retrograded glutinous rice starch and glutinous rice amylopectin could not form double helix. The IR results show that protein inhabits in glutinous rice and maize starches in a different way and appearance of C-H symmetric stretching vibration at 2852 cm(-1) in starch might be appearance of protein. Retrogradation untied the protein in glutinous amylopectin. Enthalpies of sweet potato and maize granules are higher than those of their retrograded starches. The (13)C NMR results show that retrogradation of those two starches leads to presence of β-anomers and retrogradation might decompose lipids in glutinous rice amylopectin into small molecules. Glutinous rice starch was more inclined to retrogradation than buckwheat starch. The DSC results show that the second peak temperatures for retrograded glutinous rice and buckwheat starches should be assigned to protein. The SEM results show that an obvious layer structure exists in retrograded glutinous rice amylopectin.

  13. Rapid discrimination of Panax notogeinseng of different grades by FT-IR and 2DCOS-IR

    Science.gov (United States)

    Ma, Fang; Chen, Jian-bo; Wu, Xian-xue; Zhou, Qun; Sun, Su-qin

    2016-11-01

    The herbal material of Notoginseng (the root of Panax notoginseng) is sold by "Tou" (the number of Notoginseng in every 500 g) to distinguish the grade. Normally the better quality, the few number of the "Tou" and the size of Notoginseng is bigger. In this study, three grades of Notoginseng harvested from Yunnan province were discriminated and identified by Fourier transform infrared spectroscopy (FT-IR) and two-dimensional correlation infrared spectroscopy (2DCOS-IR)). The correlation coefficient of IR spectra between the three grades of Notoginseng and starch are greater than 0.95 in the range of 1300-800 cm-1, means the main compositions of Notoginseng are starch polysaccharide. Also, when the size of Notoginseng is bigger, it may contain more polysaccharide. There is no difference in range of 815-1000 cm-1 of the 2DCOS-IR synchronous spectra of the three grades means polysaccharides possess good thermal stability. In the range of 1200-1300 cm-1 shows the inverse ration between the thermal sensitivity of C-O and the number of "Tou". Combination with the 2DCOS-IR asynchronous spectra, the response speed of amino acid (1640 cm-1) on the thermal perturbation is the fastest, followed by nitrate (1384 cm-1); the response speed of polysaccharides (1079 cm-1) is the slowest. The result proved that the 2DCOS-IR could discriminate different grades of Notoginseng.

  14. FT-IR and DSC studies of poly(vinylidene chloride-co-acrylonitrile) complexed with LiBF4

    Science.gov (United States)

    Shanthi, M.; Mathew, Chithra M.; Ulaganathan, M.; Rajendran, S.

    2013-05-01

    Poly(vinylidene chloride-co-acrylonitrile) (PVdC-co-AN) based solvent free electrolytes were prepared for different compositions of PVdC-co-AN and LiBF4 using solution casting technique. The ionic conductivity, thermal behavior, complexation and structure of polymer electrolytes have been investigated as a function of LiBF4 content at different weight ratios. DSC studies revealed that the glass transition temperature Tg decreases with the increase of salt concentration up to an optimum level. The change in the glass transition temperature (Tg) with respect to the LiBF4 concentration is reflected in the bulk resistance of the electrolytes and the sample containing 6 wt.% of LiBF4 exhibited minimum bulk resistance compared to other samples. FT-IR studies confirm the interaction of polymer and salt which is mainly between Li-cation and nitrogen atom of Ctbnd N group. The crystalline phase of polymer host is completely changed on the addition of Li salt.

  15. FT-IR spectroscopic investigation of ionic interactions in PPG 4000: AgCF3SO3 polymer electrolyte.

    Science.gov (United States)

    Suthanthiraraj, S Austin; Kumar, R; Paul, B Joseph

    2009-01-01

    The effect of salt concentration on the ubiquitous ionic interactions observed in the case of the silver ion conducting polymer electrolyte system poly(propylene glycol) (PPG)-silver triflate has been investigated using Fourier transform infrared (FT-IR) spectroscopy as a probe for the characterization of the local environment of the triflate ion in PPG-based polymer electrolytes. The maximum free anion concentrations of symmetric and asymmetric SO(3) stretching modes in the case of poly(propylene glycol) complexed with silver triflate (AgCF(3)SO(3)) corresponding to the ether oxygen metal cation ratios from 2:1 to 6:1 have been investigated in detail. The present Fourier transform infrared spectral studies of the C-O-C stretching mode have shown reduction in the intensity, due to the decrease of salt concentration. The splitting of vibrational modes has been analyzed in terms of free ions, ion pairs and aggregates. The bands of SO(3) symmetric stretching mode appearing at 1032 and 1038 cm(-1) in the chosen polymer electrolyte material have been assigned to free ions and ion pairs respectively.

  16. FT-IR, FT-Raman, SERS and computational study of 5-ethylsulphonyl-2-(o-chlorobenzyl)benzoxazole.

    Science.gov (United States)

    Mary, Y Sheena; Raju, K; Yildiz, Ilkay; Temiz-Arpaci, Ozlem; Nogueira, Helena I S; Granadeiro, Carlos M; Van Alsenoy, Christian

    2012-10-01

    FT-IR, FT-Raman and surface-enhanced Raman scattering spectra of 5-ethylsulphonyl-2-(o-chlorobenzyl)benzoxazole were recorded and analyzed. The vibrational wavenumbers were examined theoretically using the Gaussian09 set of quantum chemistry codes, and the normal modes were assigned by potential energy distribution calculations. The presence of CH(2), SO(2) and CH(3) modes in the SERS spectrum indicates the nearness of the methyl group to the metal surface which affects the orientation and metal molecule interaction. The synthesis, NMR spectra and antibacterial properties are reported. The title compound shows more inhibitory effect against Pseudomonas aeruginosa than ampicillin and found to be more potent against Klebsiella pneumoniae and drug-resistant Bacillus subtilis than the other microorganisms. A computation of the first hyperpolarizability indicates that the compound may be a good candidate as a NLO material. The RMS errors of the observed Raman and IR bands are found to be 30.93, 29.77 for HF and 9.57, 6.75 for DFT methods, respectively.

  17. FT-IR and Raman spectra and vibrational investigation of bis (4-acetylanilinium) hexachlorostannate using DFT (B3LYP) calculation

    Science.gov (United States)

    Tarchouna, S.; Chaabane, I.; Rahaiem, A. Ben

    2016-09-01

    4-acetylanilinium was used as a ligand for the synthesis of the organic/inorganic compound bis (4-acetylanilinium) hexachlorostannate. Vibrational study in the solid state was performed by FT-Raman of the free 4-acetylanilinium ligand C8H9ON+ and by FT-IR and FT-Raman spectroscopies of the [C8H10NO]2 SnCl6 compound. The comparative analysis of the Raman spectra of the title compound with that of the free ligand was discussed. The structure of the [C8H10NO]2SnCl6 was optimized by density functional theory (DFT) using B3LYP method and shows that the calculated values obtained by B3LYP/LanL2DZ basis are in a better agreement with the experimental data reported by Song et al. (2011) [1] than those obtained by B3LYP/LanL2MB basis. The vibrational frequencies are calculated using density functional theory (DFT) with the B3LYP/LanL2DZ basis, and scaled by various factors. Root mean square (RMS) value was calculated and the small difference between experimental and calculated modes has been interpreted by intermolecular interactions in the crystal.

  18. FT-IR study of the effect of zinc exposure on the biochemical contents of the muscle of Labeo rohita

    Science.gov (United States)

    Palaniappan, PL. RM.; Renju, V. B.

    2009-01-01

    Heavy metal pollution is a major environmental problem in the modern world due to increasing human activities. Zinc is an essential element involved in a wide variety of cellular processes. However, it becomes toxic when elevated concentrations are introduced into the environment. The goal of the present study is to investigate the effect of zinc exposure on the biochemical contents of the muscle tissues of freshwater species Labeo rohita using Fourier transform infrared (FT-IR) spectroscopy. Since the muscle constitutes the greatest mass of the fish that is consumed, the present study has paid particular attention to muscle component. The result reveals that the zinc exposure causes significant changes in the biochemical contents of the L. rohita muscle tissues. In addition, it causes an alteration in the protein secondary structures by decreasing the α-helix and increasing the β-sheet contents of muscle tissues. Further, it has been observed that the administration of chelating agent D-penicillamine improves the protein and lipid contents in the muscle tissues compared to zinc exposed tissues. This result shows that D-penicillamine is the effective chelator of zinc in reducing the body burden of L. rohita fingerlings.

  19. Optical Determination of Lead Chrome Green in Green Tea by Fourier Transform Infrared (FT-IR) Transmission Spectroscopy

    Science.gov (United States)

    Li, Xiaoli; Xu, Kaiwen; Zhang, Yuying; Sun, Chanjun; He, Yong

    2017-01-01

    The potential of Fourier transform infrared (FT-IR) transmission spectroscopy for determination of lead chrome green in green tea was investigated based on chemometric methods. Firstly, the qualitative analysis of lead chrome green in tea was performed based on partial least squares discriminant analysis (PLS-DA), and the correct rate of classification was 100%. And then, a hybrid method of interval partial least squares (iPLS) regression and successive projections algorithm (SPA) was proposed to select characteristic wavenumbers for the quantitative analysis of lead chrome green in green tea, and 19 wavenumbers were obtained finally. Among these wavenumbers, 1384 (C = C), 1456, 1438, 1419(C = N), and 1506 (CNH) cm-1 were the characteristic wavenumbers of lead chrome green. Then, these 19 wavenumbers were used to build determination models. The best model was achieved by least squares support vector machine (LS-SVM)algorithm with high coefficient of determination and low root-mean square error of prediction set (R2p = 0.864 and RMSEP = 0.291). All these results indicated the feasibility of IR spectra for detecting lead chrome green in green tea. PMID:28068348

  20. FT-IR reflection spectra of single crystals: resolving phonons of different symmetry without using polarised radiation

    Directory of Open Access Journals (Sweden)

    METODIJA NAJDOSKI

    2000-07-01

    Full Text Available Fourier-transform infrared (FT-IR reflection spectra, asquired at nearnormal incidence, were recorded from single crystals belonging to six crystal systems: CsCr(SO42.12H2O (alum, cubic, K2CuCl2·2H2O (Mitscherlichite, tetragonal, CaCO3 (calcite, hexagonal, KHSO4 (mercallite, orthorhombic, CaSO4·2H2O (gypsum, monoclinic and CuSO4·5H2O (chalcantite, triclinic. The acquired IR reflection spectra were further transformed into absorption spectra, employing the Kramers-Kronig transformation. Except for the cubic alums, the spectra strongly depend on the crystal face from which they were recorded; this is a consequence of anisotropy. Phonons of a given symmetry (E-species, in tetragonal/hexagonal and B-species, in monoclinic crystals may be resolved without using a polariser. The spectrum may be simplified in the case of an orthorhombic crystal, as well. The longitudinal-optical (LO and transversal-optical (TO mode frequencies were calculated in the case of optically isotropic and the simplified spectra of optically uniaxial crystals.

  1. Midinfrared FT-IR as a Tool for Monitoring Herbaceous Biomass Composition and Its Conversion to Furfural

    Directory of Open Access Journals (Sweden)

    Anna Maria Raspolli Galletti

    2015-01-01

    Full Text Available A semiquantitative analysis by means of midinfrared FT-IR spectroscopy was tuned for the simultaneous determination of cellulose, hemicellulose, and lignin in industrial crops such as giant reed (Arundo donax L. and switchgrass (Panicum virgatum L.. Ternary mixtures of pure cellulose, hemicellulose, and lignin were prepared and a direct correlation area/concentration was achieved for cellulose and lignin, whereas indirect correlations were found for hemicellulose quantification. Good correspondences between the values derived from our model and those reported in the literature or obtained according to the official Van Soest method were ascertained. Average contents of 40–45% of cellulose, 20–25% of hemicellulose, and 20–25% of lignin were obtained for different samples of giant reed species. In the case of switchgrass, a content of 36% of cellulose, 28% of hemicellulose, and 26% of lignin was achieved. This analysis was also carried out on giant reed and switchgrass residues after a mild hydrolysis step carried out with dilute hydrochloric acid for the production of furfural with good yield. Reasonable compositional data were obtained, thus allowing an indirect monitoring which helps the optimization of the hydrothermal pretreatment for furfural production from hemicellulose fractions.

  2. Investigation of Catalytic NO{sub x}, reduction with transient techniques, isotopic exchange and FT-IR spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Rahkamaa-Tolonen, K.

    2001-07-01

    Emissions from vehicles are suppressed by catalytic conversion, i.e. total oxidation of carbon monoxide and hydrocarbons and reduction of nitrogen oxides. The on-going demand for lower emissions requires more detailed knowledge about the catalytic reaction mechanisms and kinetics on the level of elementary steps, especially because of the mutual interactions in the complex reaction mixture. The reaction mechanisms for the abatement of nitrogen oxides (NO{sub x}) are of particular interest, since they are environmentally very unfriendly compounds. Transient experimental techniques can be used as a tool to understand the reaction mechanisms and to develop mathematical models allowing simulation and optimisation of the behaviour of three-way catalyst converters. In chemical kinetics, isotope-labelled reactants are frequently employed to follow reaction pathways and to determine reaction mechanisms. The kinetics and mechanisms of the catalytic reduction of nitrogen oxide (NO) by hydrogen as well as self-decomposition of NO and N{sub 2}O were studied over alumina based palladium and rhodium-alumina monoliths. In addition, NO reduction with H{sub 2} and D{sub 2}, isotope exchange of hydrogen atoms in water, ammonia and hydrogen with deuterium, as well as adsorption of ammonia and water on the Pd-monolith were studied with transient experiments. Transient step-response experiments, isotopic jumping techniques, steady- state isotopic-transient analysis, temperature programmed desorption (TPD) and Fourier-transformed infrared spectroscopy (FT-IR) were used as experimental techniques. The catalysts were characterised by carbon monoxide chemisorption, nitrogen physisorption and X-ray photoelectron spectroscopy (XPS). Nitrogen, nitrous oxide, ammonia, and water were detected as reaction products in NO reduction by hydrogen. The transient and FT-IR experiments yielded information about the surface reaction mechanisms. The dissociation of NO on the catalyst surface is the

  3. Thermoluminescence, optical absorption, photoluminescence, FT-IR and XRD studies on L-arginine doped orthophosphoric acid

    Energy Technology Data Exchange (ETDEWEB)

    Saradha, K. [Department of Physics, Selvamm Arts and Science College, Namakkal-637002, TN (India); Bangaru, S., E-mail: ssbangaru@yahoo.co.in [Department of Physics, Arignar Anna Government Arts College, Namakkal-637002, TN (India); Muralidharan, G. [Department of Physics, Gandhigram Rural University, Gandhigram-624302, TN (India)

    2013-10-15

    A paper report on the thermoluminescence (TL) optical absorption, photoluminescence (PL), single crystal XRD studies on L-arginine doped orthophosphoric acid confirm that a crystal belongs to the orthorhombic system with space group p2{sub 1}2{sub 1}2{sub 1}. The lattice of most of these crystals forming the composite, in spite of whatever the phase it belongs to, it is spatially coherent to each other with in the crystalline bulk. The functional groups present in the crystal confirms that using FT-IR technique optical absorbance shows meagre absorption from the entire visible region. The TL glow curve of L-arginine doped orthophosphoric acid sample marked a prominent peak at 125, 254 and 303 °C along with small peak at around 218 °C. Correlation with changes in optical absorption suggest that a peak at 125 °C to be related to process involving Z{sub 1} center. The peak follows first order kinetics with an activation energy of 0.033 eV and a frequency factor of 7.45×10{sup 2} and FWHM 61 nm. -- Highlights: • L-Arginine doped orthophosphoric acid has not been adequately studied. • A defect centre formed in L-arginine doped orthophosphoric acid system is assigned to F and Z{sub 1} centres. • The glow peaks are found to obey first order kinetics. • The Lattice parameter a=10.89 Å, b=7.91 Å, C=7.34 Å are in good agreement with the reported values. • The formation of a characteristic F- and centered at 520 nm is found. Such a detailed study and obtained results.

  4. Spectroscopic characterization of enzymatic flax retting: Factor analysis of FT-IR and FT-Raman data

    Science.gov (United States)

    Archibald, D. D.; Henrikssen, G.; Akin, D. E.; Barton, F. E.

    1998-06-01

    Flax retting is a chemical, microbial or enzymatic process which releases the bast fibers from the stem matrix so they can be suitable for mechanical processing before spinning into linen yarn. This study aims to determine the vibrational spectral features and sampling methods which can be used to evaluate the retting process. Flax stems were retted on a small scale using an enzyme mixture known to yield good retted flax. Processed stems were harvested at various time points in the process and the retting was evaluated by conventional methods including weight loss, color difference and Fried's test, a visual ranking of how the stems disintegrate in hot water. Spectroscopic measurements were performed on either whole stems or powders of the fibers that were mechanically extracted from the stems. Selected regions of spectra were baseline and amplitude corrected using a variant of the multiplicative signal correction method. Principal component regression and partial least-squares regression with full cross-validation were used to determine the spectral features and rate of spectral transformation by regressing the spectra against the retting time in hours. FT-Raman of fiber powders and FT-IR reflectance of whole stems were the simplest and most precise methods for monitoring the retting transformation. Raman tracks the retting by measuring the decrease in aromatic signal and subtle changes in the C-H stretching vibrations. The IR method uses complex spectral features in the fingerprint and carbonyl region, many of which are due to polysaccharide components. Both spectral techniques monitor the retting process with greater precision than the reference method.

  5. High-throughput thermal stability analysis of a monoclonal antibody by attenuated total reflection FT-IR spectroscopic imaging.

    Science.gov (United States)

    Boulet-Audet, Maxime; Byrne, Bernadette; Kazarian, Sergei G

    2014-10-07

    The use of biotherapeutics, such as monoclonal antibodies, has markedly increased in recent years. It is thus essential that biotherapeutic production pipelines are as efficient as possible. For the production process, one of the major concerns is the propensity of a biotherapeutic antibody to aggregate. In addition to reducing bioactive material recovery, protein aggregation can have major effects on drug potency and cause highly undesirable immunological effects. It is thus essential to identify processing conditions which maximize recovery while avoiding aggregation. Heat resistance is a proxy for long-term aggregation propensity. Thermal stability assays are routinely performed using various spectroscopic and scattering detection methods. Here, we evaluated the potential of macro attenuated total reflection Fourier transform infrared (ATR-FT-IR) spectroscopic imaging as a novel method for the high-throughput thermal stability assay of a monoclonal antibody. This chemically specific visualization method has the distinct advantage of being able to discriminate between monomeric and aggregated protein. Attenuated total reflection is particularly suitable for selectively probing the bottom of vessels, where precipitated aggregates accumulate. With focal plane array detection, we tested 12 different buffer conditions simultaneously to assess the effect of pH and ionic strength on protein thermal stability. Applying the Finke model to our imaging kinetics allowed us to determine the rate constants of nucleation and autocatalytic growth. This analysis demonstrated the greater stability of our immunoglobulin at higher pH and moderate ionic strength, revealing the key role of electrostatic interactions. The high-throughput approach presented here has significant potential for analyzing the stability of biotherapeutics as well as any other biological molecules prone to aggregation.

  6. DFT calculations and experimental FT-IR, FT-Raman, NMR, UV-Vis spectral studies of 3-fluorophenylboronic acid.

    Science.gov (United States)

    Karabacak, M; Kose, E; Sas, E B; Kurt, M; Asiri, A M; Atac, A

    2015-02-05

    The spectroscopic (FT-IR, FT-Raman, (1)H and (13)C NMR, UV-Vis), structural, electronic and thermodynamical properties of 3-fluorophenylboronic acid (C6H4FB(OH)2), 3FPBA) were submitted by using both experimental techniques and theoretical methods (quantum chemical calculations) in this work. The experimental infrared and Raman spectra were obtained in the region 4000-400 cm(-1) and 3500-10 cm(-1), respectively. The equilibrium geometry and vibrational spectra were calculated by using DFT (B3LYP) with 6-311++G(d,p) basis set. The vibrational wavenumbers were also corrected with scale factor to take better results for the calculated data. The total energy distributions (TED) of the vibrational modes were performed for the assignments of the title molecule by using scaled quantum mechanics (SQM) method. The NMR chemical shifts ((1)H and (13)C) were recorded in DMSO solution. The (1)H and (13)C NMR spectra were computed by using the gauge-invariant atomic orbital (GIAO) method, showing a good agreement with the experimental ones. The last one UV-Vis absorption spectra were analyzed in two solvents (ethanol and water), saved in the range of 200-400 nm. In addition these, HOMO and LUMO energies, the excitation energies, density of states (DOS) diagrams, thermodynamical properties and molecular electrostatic potential surface (MEPs) were presented. Nonlinear optical (NLO) properties and thermodynamic features were performed. The experimental results are combined with the theoretical calculations using DFT calculations to fortification of the paper. At the end of this work, the results were proved our paper had been indispensable for the literature backing.

  7. Study on antibacterial alginate-stabilized copper nanoparticles by FT-IR and 2D-IR correlation spectroscopy

    Science.gov (United States)

    Díaz-Visurraga, Judith; Daza, Carla; Pozo, Claudio; Becerra, Abraham; von Plessing, Carlos; García, Apolinaria

    2012-01-01

    Background The objective of this study was to clarify the intermolecular interaction between antibacterial copper nanoparticles (Cu NPs) and sodium alginate (NaAlg) by Fourier transform infrared spectroscopy (FT-IR) and to process the spectra applying two-dimensional infrared (2D-IR) correlation analysis. To our knowledge, the addition of NaAlg as a stabilizer of copper nanoparticles has not been previously reported. It is expected that the obtained results will provide valuable additional information on: (1) the influence of reducing agent ratio on the formation of copper nanoparticles in order to design functional nanomaterials with increased antibacterial activity, and (2) structural changes related to the incorporation of Cu NPs into the polymer matrix. Methods Cu NPs were prepared by microwave heating using ascorbic acid as reducing agent and NaAlg as stabilizing agent. The characterization of synthesized Cu NPs by ultraviolet visible spectroscopy, transmission electron microscopy (TEM), electron diffraction analysis, X-ray diffraction (XRD), and semiquantitative analysis of the weight percentage composition indicated that the average particle sizes of Cu NPs are about 3–10 nm, they are spherical in shape, and consist of zerovalent Cu and Cu2O. Also, crystallite size and relative particle size of stabilized Cu NPs were calculated by XRD using Scherrer’s formula and FT from the X-ray diffraction data. Thermogravimetric analysis, differential thermal analysis, differential scanning calorimetry (DSC), FT-IR, second-derivative spectra, and 2D-IR correlation analysis were applied to studying the stabilization mechanism of Cu NPs by NaAlg molecules. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of stabilized Cu NPs against five bacterial strains (Staphylococccus aureus ATCC 6538P, Escherichia coli ATCC 25922 and O157: H7, and Salmonella enterica serovar Typhimurium ATCC 13311 and 14028) were evaluated with macrodilution

  8. Study on antibacterial alginate-stabilized copper nanoparticles by FT-IR and 2D-IR correlation spectroscopy

    Directory of Open Access Journals (Sweden)

    Díaz-Visurraga J

    2012-07-01

    Full Text Available Judith Díaz-Visurraga,1,2 Carla Daza,2 Claudio Pozo,2 Abraham Becerra,2 Carlos von Plessing,1,2 Apolinaria García31Department of Pharmacy, Faculty of Pharmacy, University of Concepcion; 2Research Center of Advanced Polymers (CIPA, CONICYT REGIONAL/CIPA R08C1002; 3Department of Microbiology, Faculty of Biological Sciences, University of Concepcion, Concepción, ChileBackground: The objective of this study was to clarify the intermolecular interaction between antibacterial copper nanoparticles (Cu NPs and sodium alginate (NaAlg by Fourier transform infrared spectroscopy (FT-IR and to process the spectra applying two-dimensional infrared (2D-IR correlation analysis. To our knowledge, the addition of NaAlg as a stabilizer of copper nanoparticles has not been previously reported. It is expected that the obtained results will provide valuable additional information on: (1 the influence of reducing agent ratio on the formation of copper nanoparticles in order to design functional nanomaterials with increased antibacterial activity, and (2 structural changes related to the incorporation of Cu NPs into the polymer matrix.Methods: Cu NPs were prepared by microwave heating using ascorbic acid as reducing agent and NaAlg as stabilizing agent. The characterization of synthesized Cu NPs by ultraviolet visible spectroscopy, transmission electron microscopy (TEM, electron diffraction analysis, X-ray diffraction (XRD, and semiquantitative analysis of the weight percentage composition indicated that the average particle sizes of Cu NPs are about 3–10 nm, they are spherical in shape, and consist of zerovalent Cu and Cu2O. Also, crystallite size and relative particle size of stabilized Cu NPs were calculated by XRD using Scherrer’s formula and FT from the X-ray diffraction data. Thermogravimetric analysis, differential thermal analysis, differential scanning calorimetry (DSC, FT-IR, second-derivative spectra, and 2D-IR correlation analysis were applied to

  9. In-Situ FT-IR Investigation of Partial Oxidation of Methane to Syngas over Rh/SiO2 Catalyst

    Institute of Scientific and Technical Information of China (English)

    Tinghua Wu; Dongmin Lin; Ying Wu; Xiaoping Zhou; Qiangu Yan; Weizheng Weng; Huilin Wan

    2007-01-01

    Partial oxidation of methane to syngas(POM)over Rh/SiO2 catalyst was investigated using in-situ FT-IR.when methane interacted with 1.0wt%Rh/SiO2 catalyst,it was dissociated to adsorbed hydrogen and CHx species.The adsorbed hydrogen atoms were transferred to SiO2 surface by "spill-over" and reacted with lattice oxygen to form surface-OH species.POM mechanism was investigated over Rh/SiO2 catalyst using in-situ FT-IR.It Was found that CO2 Was formed before CO could be detected when CH4 and O2 were introduced over the preoxidized Rh/SiO2 catalyst,whereas CO Was detected before CO2 Was formed over the prereduced Rh/SiO2 catalyst.

  10. Theoretical (DFT) and experimental (FT-IR, FT-Raman, FT-NMR) investigations on 7-Acetoxy-4-(bromomethyl)coumarin

    Science.gov (United States)

    Erdogdu, Y.; Saglam, S.; Dereli, Ö.

    2015-09-01

    An analysis of the results of the structural and spectroscopic studies of 7-Acetoxy-4-(bromomethyl) coumarin (7A4BMC) molecule were performed by FT-IR, FT-Raman, FT-NMR and quantum chemical calculations. The FT-IR and FT-Raman spectra of 7A4BMC were recorded in the 400-4000 and 50-3500 cm-1 region, respectively. The molecular conformations of 7A4BMC were computed at the B3LYP/6-311++G(d,p) level of theory. Molecular structure and spectral calculations were calculated by means of B3LYP with 6-311++G(d,p), cc-pVDZ and cc-pVTZ basis sets. The whole vibrational characteristics of the 7A4BMC molecule are given.

  11. Simultaneous monitoring of curing shrinkage and degree of cure of thermosets by attenuated total reflection Fourier transform infrared (ATR FT-IR) spectroscopy.

    Science.gov (United States)

    Fernàndez-Francos, Xavier; Kazarian, Sergei G; Ramis, Xavier; Serra, Àngels

    2013-12-01

    We present a novel methodology to simultaneously monitor of the degree of cure and curing shrinkage of thermosetting formulations. This methodology is based on the observation of changes in the infrared absorption of reactive functional groups and the groups used as a standard reference for normalization. While the optical path length is exact and controlled in transmission infrared spectroscopy, in attenuated total reflection Fourier transform infrared (ATR FT-IR), the exact determination of volume changes requires the measurement of the refractive indices of the studied system throughout the curing process or at least an indirect parallel measurement of this property. The methodology presented here allows one to achieve quantitative measurements of the degree of cure and shrinkage for thermosets using in situ ATR FT-IR spectroscopy.

  12. An investigation of the effect of silicone oil on polymer intraocular lenses by means of PALS, FT-IR and Raman spectroscopies

    Science.gov (United States)

    Chamerski, Kordian; Lesniak, Magdalena; Sitarz, Maciej; Stopa, Marcin; Filipecki, Jacek

    2016-10-01

    The effect of the polydimethylsiloxane (PDMS) based silicone oil, that is widely used in vitreoretinal surgery, on internal structures of the polymer intraocular lenses was investigated. The effect of PDMS was studied on the polymethyl methacrylate (PMMA) rigid lenses and poly(2-hydroxyethyl methacrylate) (PHEMA) flexible lenses. The research was carried out by means of the positron lifetime spectroscopy (PALS) as well as the infrared spectroscopy (FT-IR) and the Raman spectroscopy (RS). The studies involving the use of PALS and FT-IR methods have revealed that the PHEMA based lenses absorbed, whereas the PMMA lenses did not absorb, silicone oil. The results obtained with the use of the RS method were inconclusive, probably due to the too low intensity of the characteristic PDMS bands. The evidence from this study was discussed in terms of physics and related to the clinical use of both silicone oil and intraocular lenses.

  13. 1H NMR and FT-IR dataset based structural investigation of poly(amic acids and polyimides from 4,4′-diaminostilbene

    Directory of Open Access Journals (Sweden)

    Amit Kumar

    2016-06-01

    Full Text Available Structural investigation of polymers by various available analytical methods is important in order to correlate the structure with polymer properties for which understanding of polymer structure is very important factor. The data presented here in this article shows the 1H NMR spectra used for the characterization of prepared poly(amic acids (PAAs. It is often difficult to assigns the peak in NMR of polymers due to its complexity. Data presented here helps in assigning the proton peak in complex NMR of PAAs prepared from aromatic diamines. Further functionality in polymer chains can be confirmed by FT-IR spectra. Change in functionality during some reaction or process can be monitored by disappearance or appearance of peaks in FT-IR. The complete imidization of PAAs to Polyimides (PIs is difficult to analyze because of the chemical stability i.e. insolubility of PIs in most of the solvent therefore the completion of imidization process was confirmed using FTIR.

  14. Molecular structure, vibrational spectral assignments (FT-IR and FT-RAMAN), NMR, NBO, HOMO-LUMO and NLO properties of O-methoxybenzaldehyde based on DFT calculations

    Science.gov (United States)

    Vennila, P.; Govindaraju, M.; Venkatesh, G.; Kamal, C.

    2016-05-01

    Fourier transform - Infra red (FT-IR) and Fourier transform - Raman (FT-Raman) spectroscopic techniques have been carried out to analyze O-methoxy benzaldehyde (OMB) molecule. The fundamental vibrational frequencies and intensity of vibrational bands were evaluated using density functional theory (DFT). The vibrational analysis of stable isomer of OMB has been carried out by FT-IR and FT-Raman in combination with theoretical method simultaneously. The first-order hyperpolarizability and the anisotropy polarizability invariant were computed by DFT method. The atomic charges, hardness, softness, ionization potential, electronegativity, HOMO-LUMO energies, and electrophilicity index have been calculated. The 13C and 1H Nuclear magnetic resonance (NMR) have also been obtained by GIAO method. Molecular electronic potential (MEP) has been calculated by the DFT calculation method. Electronic excitation energies, oscillator strength and excited states characteristics were computed by the closed-shell singlet calculation method.

  15. In situ FT-IR spectroscopy investigations of carbon nanotubes supported Co-Mo catalysts for selective hydrodesulfurization of FCC gasoline

    Institute of Scientific and Technical Information of China (English)

    Jingcheng Zhang; Wenkun Yin; Hongyan Shang; Chenguang Liu

    2008-01-01

    To better understand the nature of carbon nanotubes supported Co-Mo catalysts (Co-Mo/CNTs) for selective hy-drodesulfurization (HDS) of fluid catalytic cracking (FCC) gasoline, studies are carried out using in situ Fourier transform infrared spectroscopy (FT-IR). The catalytic performances of Co-Mo/CNTs catalysts were evaluated with a mixture of cy-clohexane, diisobutylene, cyclohexene, 1-octene (60 : 30 : 5 : 5, volume ratio) and thiophene (0.5%, ratio of total weight) as model compounds to simulate FCC gasoline. The HDS experimental results suggested that the HDS activity and selectivity of Co-Mo/CNTs catalysts were affected by Co/Mo ratio; the optimal Co/Mo atomic ratio is about 0.4, and the optimum reaction temperature is 260 ℃. The in situ FT-IR studies revealed that 1-octene can be completely saturated at 200 ℃. In the FT-IR spectra of diisobutylene, the characteristic absorption peak around 3081 cm-1 for the stretching vibration peak of=C-H bond was still clear at 320℃, indicating that diisobutylene is difficult to be hydrogenated. As for the thiophene, no characteristic absorption peak could be found around 3092 cm-1 and 835 cm-1 when the reaction temperature was raised to 280 ℃, indi-cating that thiophene had been completely hydrodesulfurized. On the basis of FT-IR results, it can be deduced that thiopbene HDS reaction occurred mainly through direct hydrogenolysis route, whereas thiophene HDS and diisobutylene hydrogenation reaction over Co-Mo/CNTs catalysts might occur on two different kinds of active sites.

  16. FT-IR Spectroscopic characterization of the intermediates in the selective catalytic reduction of NO with methane on Pd/ZrO(formula)-WO(formula) catalyst

    OpenAIRE

    Çayırtepe, İlknur

    2004-01-01

    Cataloged from PDF version of article. This work involves in situ FT-IR spectroscopic study of the routes of formation, composition and thermal stability of strongly bound NOx complexes on the surface of Pd/tungstated zirconia, and transformation of the surface NOx complexes in the presence of methane in order to elucidate the mechanism of selective catalytic reduction of NO with methane. Sol-gel polymer-template synthesis was chosen to obtain high surface area in the prepar...

  17. Técnicas FT-IR (PAS, UATR e Objetiva ATR Aplicadas à Caracterização de EPDM Modificada com Plasma

    Directory of Open Access Journals (Sweden)

    Renata Patrícia dos Santos

    2014-06-01

    Full Text Available Técnicas FT-IR (UATR, PAS e MIC, com objetiva ATR foram escolhidas para a caracterização da superfície da borracha de EPDM vulcanizada, após tratamento em plasma de Ar/O2 e N2/H2/Ar gerado em micro-ondas. Após tratamento, grupos oxigenados foram detectados por UATR e MIC/FT-IR, com objetiva ATR para as duas misturas gasosas, e possíveis grupos nitrogenados foram inseridos na superfície das amostras tratadas com plasma de N2/H2/Ar. A análise MIC/FT-IR sugeriu a formação de grupos em uma camada mais externa, para as amostras tratadas com plasma de N2/H2/Ar, sendo possível observar a redução na intensidade das bandas da absorção do CH2 e CH3, o que pode estar relacionado ao fato de o nitrogênio ser um gás menos permeável que o oxigênio. Diferentes velocidades, 0,05 cm.s-1 e 0,2 cm.s-1, foram utilizadas na análise PAS para avaliar a superfície após tratamento, e apenas para a velocidade 0,05 cm.s-1 com plasma de Ar/O2 alterações espectroscópicas foram detectadas. A redução na medida de ângulo de contato e o aumento na resistência ao descascamento da colagem indicaram melhoras nas propriedades adesivas da superfície. Falhas de adesão foram observadas entre a interface do filme de adesivo de PU e da borracha de EPDM, e confirmados por UATR/FT-IR.

  18. Chemical profiling and adulteration screening of Aquilariae Lignum Resinatum by Fourier transform infrared (FT-IR) spectroscopy and two-dimensional correlation infrared (2D-IR) spectroscopy.

    Science.gov (United States)

    Qu, Lei; Chen, Jian-Bo; Zhang, Gui-Jun; Sun, Su-Qin; Zheng, Jing

    2017-03-05

    As a kind of expensive perfume and valuable herb, Aquilariae Lignum Resinatum (ALR) is often adulterated for economic motivations. In this research, Fourier transform infrared (FT-IR) spectroscopy is employed to establish a simple and quick method for the adulteration screening of ALR. First, the principal chemical constituents of ALR are characterized by FT-IR spectroscopy at room temperature and two-dimensional correlation infrared (2D-IR) spectroscopy with thermal perturbation. Besides the common cellulose and lignin compounds, a certain amount of resin is the characteristic constituent of ALR. Synchronous and asynchronous 2D-IR spectra indicate that the resin (an unstable secondary metabolite) is more sensitive than cellulose and lignin (stable structural constituents) to the thermal perturbation. Using a certified ALR sample as the reference, the infrared spectral correlation threshold is determined by 30 authentic samples and 6 adulterated samples. The spectral correlation coefficient of an authentic ALR sample to the standard reference should be not less than 0.9886 (p=0.01). Three commercial adulterated ALR samples are identified by the correlation threshold. Further interpretation of the infrared spectra of the adulterated samples indicates the common adulterating methods - counterfeiting with other kind of wood, adding ingredient such as sand to increase the weight, and adding the cheap resin such as rosin to increase the content of resin compounds. Results of this research prove that FT-IR spectroscopy can be used as a simple and accurate quality control method of ALR.

  19. Combining Raman and FT-IR spectroscopy with quantitative isotopic labeling for differentiation of E. coli cells at community and single cell levels.

    Science.gov (United States)

    Muhamadali, Howbeer; Chisanga, Malama; Subaihi, Abdu; Goodacre, Royston

    2015-04-21

    There is no doubt that the contribution of microbially mediated bioprocesses toward maintenance of life on earth is vital. However, understanding these microbes in situ is currently a bottleneck, as most methods require culturing these microorganisms to suitable biomass levels so that their phenotype can be measured. The development of new culture-independent strategies such as stable isotope probing (SIP) coupled with molecular biology has been a breakthrough toward linking gene to function, while circumventing in vitro culturing. In this study, for the first time we have combined Raman spectroscopy and Fourier transform infrared (FT-IR) spectroscopy, as metabolic fingerprinting approaches, with SIP to demonstrate the quantitative labeling and differentiation of Escherichia coli cells. E. coli cells were grown in minimal medium with fixed final concentrations of carbon and nitrogen supply, but with different ratios and combinations of (13)C/(12)C glucose and (15)N/(14)N ammonium chloride, as the sole carbon and nitrogen sources, respectively. The cells were collected at stationary phase and examined by Raman and FT-IR spectroscopies. The multivariate analysis investigation of FT-IR and Raman data illustrated unique clustering patterns resulting from specific spectral shifts upon the incorporation of different isotopes, which were directly correlated with the ratio of the isotopically labeled content of the medium. Multivariate analysis results of single-cell Raman spectra followed the same trend, exhibiting a separation between E. coli cells labeled with different isotopes and multiple isotope levels of C and N.

  20. Detection Limits for Blood on Fabrics Using Attenuated Total Reflection Fourier Transform Infrared (ATR FT-IR) Spectroscopy and Derivative Processing.

    Science.gov (United States)

    Lu, Zhenyu; DeJong, Stephanie A; Cassidy, Brianna M; Belliveau, Raymond G; Myrick, Michael L; Morgan, Stephen L

    2016-06-27

    Attenuated total reflection Fourier transform infrared spectroscopy (ATR FT-IR) was used to detect blood stains based on signature protein absorption in the mid-IR region, where intensity changes in the spectrum can be related to blood concentration. Partial least squares regression (PLSR) was applied for multivariate calibrations of IR spectra of blood dilutions on four types of fabric (acrylic, nylon, polyester, and cotton). Gap derivatives (GDs) were applied as a preprocessing technique to optimize the performance of calibration models. We report a much improved IR detection limit (DL) for blood on cotton (2700× in dilution factor units) and the first IR DL reported for blood on nylon (250×). Due to sample heterogeneity caused by fabric hydrophobicity, acrylic fabric produced variable ATR FT-IR spectra that caused poor DLs in concentration units compared to previous work. Polyester showed a similar problem at low blood concentrations that lead to a relatively poor DL as well. However, the increased surface sensitivity and decreased penetration depth of ATR FT-IR make it an excellent choice for detection of small quantities of blood on the front surface of all fabrics tested (0.0010 µg for cotton, 0.0077 µg for nylon, 0.011 µg for acrylic, and 0.0066 µg for polyester).

  1. Analysis of clay smoking pipes from archeological sites in the region of the Guanabara Bay (Rio de Janeiro, Brazil) by FT-IR

    Science.gov (United States)

    Freitas, Renato P.; Ribeiro, Iohanna M.; Calza, Cristiane; Oliveira, Ana L.; Silva, Mariane L.; Felix, Valter S.; Ferreira, Douglas S.; Coelho, Felipe A.; Gaspar, Maria D.; Pimenta, André R.; Medeiros, Elanio A.; Lopes, Ricardo T.

    2016-06-01

    In this study, twenty samples of clay smoking pipes excavated in an 18 km2 area between the Macacu and Caceribu rivers, in the municipality of Itaboraí, Rio de Janeiro, Brazil were analyzed by FT-IR technique. The samples, excavated in different archeological sites of the region, are dated between the seventeenth and the nineteenth centuries and are part of the material culture left by Africans and African descendants that lived in the complex. FT-IR analyses and complementary SEM-EDS studies showed that the clay paste used in the manufacture of smoking pipes, mostly handcrafted, is composed of quartz, feldspar, phyllosilicates and iron oxides. Multivariate statistical tests (PCA) were applied to FT-IR data to assess the interactions between the archeological sites. The results indicated that one archeological site - Macacu IV - is greatly related to the other sites. The results obtained have helped archeologists and anthropologists in better understanding the manufacturing process employed in ancient ceramic artifacts produced during the period of colonial Brazil.

  2. Chemical profiling and adulteration screening of Aquilariae Lignum Resinatum by Fourier transform infrared (FT-IR) spectroscopy and two-dimensional correlation infrared (2D-IR) spectroscopy

    Science.gov (United States)

    Qu, Lei; Chen, Jian-bo; Zhang, Gui-Jun; Sun, Su-qin; Zheng, Jing

    2017-03-01

    As a kind of expensive perfume and valuable herb, Aquilariae Lignum Resinatum (ALR) is often adulterated for economic motivations. In this research, Fourier transform infrared (FT-IR) spectroscopy is employed to establish a simple and quick method for the adulteration screening of ALR. First, the principal chemical constituents of ALR are characterized by FT-IR spectroscopy at room temperature and two-dimensional correlation infrared (2D-IR) spectroscopy with thermal perturbation. Besides the common cellulose and lignin compounds, a certain amount of resin is the characteristic constituent of ALR. Synchronous and asynchronous 2D-IR spectra indicate that the resin (an unstable secondary metabolite) is more sensitive than cellulose and lignin (stable structural constituents) to the thermal perturbation. Using a certified ALR sample as the reference, the infrared spectral correlation threshold is determined by 30 authentic samples and 6 adulterated samples. The spectral correlation coefficient of an authentic ALR sample to the standard reference should be not less than 0.9886 (p = 0.01). Three commercial adulterated ALR samples are identified by the correlation threshold. Further interpretation of the infrared spectra of the adulterated samples indicates the common adulterating methods - counterfeiting with other kind of wood, adding ingredient such as sand to increase the weight, and adding the cheap resin such as rosin to increase the content of resin compounds. Results of this research prove that FT-IR spectroscopy can be used as a simple and accurate quality control method of ALR.

  3. Complementary online aerosol mass spectrometry and offline FT-IR spectroscopy measurements: Prospects and challenges for the analysis of anthropogenic aerosol particle emissions

    Science.gov (United States)

    Faber, Peter; Drewnick, Frank; Bierl, Reinhard; Borrmann, Stephan

    2017-10-01

    The aerosol mass spectrometer (AMS) is well established in investigating highly time-resolved dynamics of submicron aerosol chemical composition including organic aerosol (OA). However, interpretation of mass spectra on molecular level is limited due to strong fragmentation of organic substances and potential reactions inside the AMS ion chamber. Results from complementary filter-based FT-IR absorption measurements were used to explain features in high-resolution AMS mass spectra of different types of OA (e.g. cooking OA, cigarette smoking OA, wood burning OA). Using this approach some AMS fragment ions were validated in this study as appropriate and rather specific markers for a certain class of organic compounds for all particle types under investigation. These markers can therefore be used to get deeper insights in the chemical composition of OA based on AMS mass spectra in upcoming studies. However, the specificity of other fragment ions such as C2H4O2+ (m/z 60.02114) remains ambiguous. In such cases, complementary FT-IR measurements allow the interpretation of highly time-resolved AMS mass spectra at the level of molecular functional groups. Furthermore, this study discusses the challenges in reducing inorganic interferences (e.g. from water and ammonium salts) in FT-IR spectra of atmospheric aerosols to decrease spectral uncertainties for better comparisons and, thus, to get more robust results.

  4. Discrimination of edible oils and fats by combination of multivariate pattern recognition and FT-IR spectroscopy: A comparative study between different modeling methods

    Science.gov (United States)

    Javidnia, Katayoun; Parish, Maryam; Karimi, Sadegh; Hemmateenejad, Bahram

    2013-03-01

    By using FT-IR spectroscopy, many researchers from different disciplines enrich the experimental complexity of their research for obtaining more precise information. Moreover chemometrics techniques have boosted the use of IR instruments. In the present study we aimed to emphasize on the power of FT-IR spectroscopy for discrimination between different oil samples (especially fat from vegetable oils). Also our data were used to compare the performance of different classification methods. FT-IR transmittance spectra of oil samples (Corn, Colona, Sunflower, Soya, Olive, and Butter) were measured in the wave-number interval of 450-4000 cm-1. Classification analysis was performed utilizing PLS-DA, interval PLS-DA, extended canonical variate analysis (ECVA) and interval ECVA methods. The effect of data preprocessing by extended multiplicative signal correction was investigated. Whilst all employed method could distinguish butter from vegetable oils, iECVA resulted in the best performances for calibration and external test set with 100% sensitivity and specificity.

  5. Spectroscopic (FT-IR, FT-Raman, UV, NMR, NBO) investigation and molecular docking study of (R)-2-Amino-1-PhenylEthanol

    Science.gov (United States)

    Subashini, K.; Periandy, S.

    2016-08-01

    A systematic spectroscopic study of (R)-2-Amino-1-Phenylethanol was carried out using FT-IR, FT-Raman, NMR and UV analysis. FT-IR (4000-400 cm-1) and FT-Raman (4000-100 cm-1) spectrum of the title molecule were recorded in solid phase, the 1H and 13C NMR spectra were recorded in CDCl3 (deuterated chloroform) solution phase and the UV-Vis (200-800 nm) spectrum was recorded in gas phase and ethanol solution phase. Potential energy surface (PES) scan was performed using B3LYP functional with 6-311++G (d, p) basis set. The geometrical parameters (such as bond length, bond angle, dihedral angles) and theoretical frequencies of the title compound were studied from density functional theory (DFT) using B3LYP and B3PW91 functionals with 6-311++G (d, p) basis sets. The computed frequencies were scaled and compared with the experimental values and potential energy distribution (PED) has been tabulated. A comparative study of atomic charges was made by calculating Mulliken, Natural Population Analysis (NPA) and Electrostatic Potential (ESP) simultaneously, with B3LYP/6-311++G (d, p) basis set. 1H and 13C NMR spectra were recorded and chemical shifts were compared to TMS by Gauge-Independent Atomic Orbital (GIAO) method. Electronic properties such as excitation energy, energy gap between HOMO and LUMO was calculated using time dependent DFT technique. NBO analysis, which predicts the different possibilities of electronic transition in the molecule, was computed using B3PW91 functional with 6-311++G (d, p) basis set. The thermodynamic properties such as heat capacity, entropy and enthalpy at different temperatures were computed and analyzed. Molecular docking study shows that the secondary hydroxyl group and the primary amino group in the aliphatic chain attached to the benzene ring are crucial for binding and the title compound might exhibit inhibitory activity against Bacteroides fragilis (3P24) and may act as anti-bacterial agent.

  6. FT-IR, micro-Raman and UV-vis spectroscopic and quantum chemical calculation studies on the 6-chloro-4-hydroxy-3-phenyl pyridazine compound

    Science.gov (United States)

    Sarıkaya, Ebru Karakaş; Bahçeli, Semiha; Varkal, Döndü; Dereli, Ömer

    2017-08-01

    In this work, the study of the6-chloro-4-hydroxy-3-phenyl pyridazine compound, (C10 H7 N2 O Cl with synonym 4-pyridazinol, 6-chloro-3-phenyl-), was verified experimentally by using the Fourier Transformed Infrared (FT-IR), micro-Raman and UV/vis (in N,N-dimethylformamide solvent) spectroscopies. Furthermore, the optimized molecular geometry, conformatinal analysis, vibrational frequencies, the simulated UV/vis spectra (in gas and in N,N-dimethylformamide solvent), 1H and 13C NMR chemical shift (in gas, in chloroform and N,N-dimethylformamide in solvents) values, HOMO-LUMO analysis, the molecular electrostatic potential (MEP) surface and thermodynamic parameters ofthe6-chloro-4-hydroxy-3-phenyl pyridazine compound were calculated by using DFT/B3LYP method with 6-311++G(d,p) basis set in ground state. The comparison of the calculated and vibrational frequencies with the experimental values provides important information about the title compound.

  7. DFT studies on antioxidant mechanisms, electronic properties, spectroscopic (FT-IR and UV) and NBO analysis of C-glycosyl flavone, an isoorientin

    Science.gov (United States)

    Deepha, V.; Praveena, R.; Sadasivam, K.

    2015-02-01

    The relationship between structure and electronic properties of isoorientin, a C-glycoside flavone is investigated to relate its radical scavenging activity using molecular descriptors. To elucidate the antioxidant activity of polyphenolics, three mechanisms namely hydrogen atom transfer (HAT), single electron transfer-proton transfer (SET-PT) and sequential proton-loss electron-transfer (SPLET) are employed. In gas-phase, Osbnd H bond dissociation enthalpies (BDE), ionization potential (IP), proton dissociation enthalpies (PDE), proton affinity (PA) and electron transfer enthalpy (ETE) are computed and correlated relevant to antioxidant potency of the title compound employing DFT/6-311G(d,p) protocol. The theoretically simulated FT-IR and the UV-visible absorption spectra have been compared with the experimental data. Based on the absorbed UV spectra and TD-DFT calculations, assignment of the absorption bands are carried out. In addition, formation of intramolecular hydrogen bond and most possible interaction sites are explained by using natural bond orbital (NBO) analysis.

  8. Synthesis, spectroscopic (FT-IR, FT-Raman, NMR, UV-Visible), first order hyperpolarizability, NBO and molecular docking study of (E)-1-(4-bromobenzylidene)semicarbazide

    Science.gov (United States)

    Raja, M.; Muhamed, R. Raj; Muthu, S.; Suresh, M.

    2017-01-01

    The compound (E)-1-(4-bromobenzylidene)semicarbazide(4BSC) was synthesized and characterized by FT-IR, FT-Raman, UV-Visible, 1HNMR and 13CNMR spectra. The optimized molecular geometry(bond length, bond angle), the complete vibrational frequency, the infrared intensities and the Raman scattering activities were calculated by using density functional theory(DFT) B3LYP method with the help of 6-311++G(d,p) basis set. From the recorded UV-Visible spectrum, the electronic properties such as excitation energies, wavelength, band gap and oscillator strength are evaluated by TD-DFT in DMSO solution and gas phase methods using 6-311++G(d,p) basis set. The calculated HOMO - LUMO band gap energies confirm that charge transfer occurs within the molecule. The 1H and 13C nuclear magnetic resonance (NMR) chemical shifts of the molecule are calculated by the gauge-independent atomic orbital (GIAO) method and compared with experimental results. The hyperconjugative interaction energy E(2) and electron densities of donor (i) and acceptor (j) bonds were calculated using NBO analysis. Besides NLO and MEP were also calculated and interpreted. To study the biological activity of the investigation molecule, molecular docking was done to identify the hydrogen bond lengths and binding energy with different antimicrobial protein. Thermodynamic properties of the title compound at different temperatures have been calculated, revealing the correlations the heat capacity (C), entropy (S) and enthalpy changes (H) and temperatures.

  9. FT-IR/ATR法によるコーヒー飲料の赤外分光特性抽出と主要複数成分の同時定量

    OpenAIRE

    橋本, 篤; 森, 久典; 狩野, 幹人; 亀岡, 孝治; 島津, 秀雄; 小林, 香織; Hashimoto, Atsushi; Mori, Hisanori; Kanou, Mikihito; Kameoka, Takaharu; Shimazu, Hideo; Kobayashi, Kaori

    2009-01-01

    We developed a mid-infrared (MIR) spectroscopic evaluation method of brewed coffee, whose quality and taste depend highly on properties such as the geographical origin and the roasting, grinding, blending, and extraction conditions, using an FT-IR spectrometer equipped with an attenuated total reflectance (ATR) accessory. In addition, the simultaneous content determination of the main components of coffee drink was performed by applying the FT-IR/ATR method. We studied the effects of differen...

  10. Myowater dynamics and protein secondary structural changes as affected by heating rate in three pork qualities: a combined FT-IR microspectroscopic and 1H NMR relaxometry study.

    Science.gov (United States)

    Wu, Zhiyun; Bertram, Hanne Christine; Böcker, Ulrike; Ofstad, Ragni; Kohler, Achim

    2007-05-16

    The objective of this study was to investigate the influence of heating rate on myowater dynamics and protein secondary structures in three pork qualities by proton NMR T2 relaxation and Fourier transform infrared (FT-IR) microspectroscopy measurements. Two oven temperatures at 100 degrees C and 200 degrees C corresponding to slow and fast heating rates were applied on three pork qualities (DFD, PSE, and normal) to an internal center temperature of 65 degrees C. The fast heating induced a higher cooking loss, particularly for PSE meat. The water proton T21 distribution representing water entrapped within the myofibrillar network was influenced by heating rate and meat quality. Fast heating broadened the T21 distribution and decreased the relaxation times of the T21 peak position for three meat qualities. The changes in T21 relaxation times in meat can be interpreted in terms of chemical and diffusive exchange. FT-IR showed that fast heating caused a higher gain of random structures and aggregated beta-sheets at the expense of native alpha-helixes, and these changes dominate the fast-heating-induced broadening of T21 distribution and reduction in T21 times. Furthermore, of the three meat qualities, PSE meat had the broadest T21 distribution and the lowest T21 times for both heating rates, reflecting that the protein aggregation of PSE caused by heating is more extensive than those of DFD and normal, which is consistent with the IR data. The present study demonstrated that the changes in T2 relaxation times of water protons affected by heating rate and raw meat quality are well related to the protein secondary structural changes as probed by FT-IR microspectroscopy.

  11. Application of MCR-ALS to reveal intermediate conformations in the thermally induced α-β transition of poly-L-lysine monitored by FT-IR spectroscopy

    Science.gov (United States)

    Alcaráz, Mirta R.; Schwaighofer, Andreas; Goicoechea, Héctor; Lendl, Bernhard

    2017-10-01

    Temperature-induced conformational transitions of poly-L-lysine were monitored with Fourier-transform infrared (FT-IR) spectroscopy between 10 °C and 70 °C. Chemometric analysis of dynamic IR spectra was performed by multivariate curve analysis-alternating least squares (MCR-ALS) of the amide I‧ and amide II‧ spectral region. With this approach, the pure spectral and concentration profiles of the conformational transition were obtained. Beside the initial α-helical, the intermediate random coil/extended helices and the final β-sheet structure, an additional intermediate PLL conformation was identified and attributed to a transient β-sheet structure.

  12. In situ FT-IR studies on the mechanism of selective catalytic reduction of NOx by propene over SnO2/Al2O3 catalyst.

    Science.gov (United States)

    Liu, Zhiming; Woo, Seong Ihl; Lee, Won Su

    2006-12-28

    The mechanism of the selective catalytic reduction (SCR) of NOx by propene over SnO2/Al2O3 catalyst in the presence of oxygen has been investigated using in situ Fourier transform infrared (FT-IR) spectroscopy. In situ IR measurements indicate that acetate and formate, which are the derivatives of the partial oxidation of propene, play a crucial role in the formation of NCO by reacting with the reactive monodentate nitrate species. The resulting NCO species subsequently reacts with NOx to form N2. The presence of oxygen substantially contributes to the partial oxidation of propene and thus shows a promoting effect for the NOx reduction.

  13. DETERMINATION OF CRYSTALLINITY INDEX OF CARBOHYDRATE COMPONENTS IN HEMP (CANNABIS SATIVA L. WOODY CORE BY MEANS OF FT-IR SPECTROSCOPY

    Directory of Open Access Journals (Sweden)

    Esat Gümüşkaya

    2005-04-01

    Full Text Available In this study; it was investigated chemical compositions of hemp woody core and changes in crystallinity index of its carbohydrate components by using FT-IR spectroscopy was investigated. It was determined that carbohyrate components ratio in hemp woody core were similar to that in hard wood, but lignin content in hemp woody core was higher than in hard wood. Crystallinity index of carbohydrate components in hemp woody core increased by removing amorphous components. It was designated that monoclinic structure in hemp woody core and its carbohydrate components was dominant, but triclinic ratio increased by treated chemical isolation of carbohydrate from hemp woody core.

  14. Direct Observation of the Kinetically Relevant Site of CO Hydrogenation on Supported Ru Catalyst at 700 K by Time-Resolved FT-IR Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Frei, Heinz; Wasylenko, Walter; Frei, Heinz

    2008-06-04

    Time-resolved FT-IR spectra of carbon monoxide hydrogenation over alumina-supported ruthenium particles were recorded on themillisecond time scale at 700 K using pulsed release of CO and a continuous flow of H2/N2 (ratio 0.067 or 0.15, 1 atm total pressure). Adsorbed carbon monoxide was detected along with gas phase products methane (3016 and 1306 cm-1), water (1900 +- 1300 cm-1), and carbon dioxide (2348 cm-1). Aside from adsorbed CO, no other surface species were observed. The rate of formation of methane is 2.5 +- 0.4 s-1 and coincides with the rate of carbon dioxide growth (3.4 +- 0.6 s-1), thus indicating that CH4 and CO2 originate from a common intermediate. The broad band of adsorbed carbon monoxide has a maximum at 2010 cm-1 at early times (36 ms) that shifts gradually to 1960 cm-1 over a period of 3 s as a result of the decreasing surface concentration of CO. Kinetic analysis of the adsorbed carbon monoxide reveals that surface sites absorbing at the high frequency end of the infrared band are temporally linked to gas phase product growth. Specifically, a (linear) CO site at 2026 cm-1 decays with a rate constant of 2.9 +- 0.1 s-1, which coincides with the rise constant of CH4. This demonstrates that the linear CO site at 2026 cm-1 is the kinetically most relevant one for the rate-determining CO dissociation step under reaction conditions at 700 K.

  15. Application of spectroscopic methods for identification (FT-IR, Raman spectroscopy) and determination (UV, EPR) of quercetin-3-O-rutinoside. Experimental and DFT based approach.

    Science.gov (United States)

    Paczkowska, Magdalena; Lewandowska, Kornelia; Bednarski, Waldemar; Mizera, Mikołaj; Podborska, Agnieszka; Krause, Anna; Cielecka-Piontek, Judyta

    2015-04-05

    Vibrational (FT-IR, Raman) and electronic (UV, EPR) spectral measurements were performed for an analysis of rutin (quercetin-3-O-rutinoside) obtained from Rutaofficinalis. The identification of rutin was done with the use of FT-IR and Raman spectra. Those experimental spectra were determined with the support of theoretical calculations based on a DFT method with the B3LYP hybrid functional and 6-31G(d,p) basis set. The application of UV and EPR spectra was found to be a suitable analytical approach to the evaluation of changes in rutin exposed to certain physicochemical factors. Differences in absorbance observed in direct UV spectra were used to monitor changes in the concentration of rutin in degraded samples. Spectra of electron paramagnetic resonance allowed studying the process of free-radical quenching in rutin following its exposure to light. The molecular electrostatic potential (MEP) and frontier molecular orbitals (LUMO-HOMO) were also determined in order to predict structural changes and reactive sites in rutin.

  16. Observations of surface-mediated reduction of Pu(VI) to Pu(IV) on hematite nanoparticles by ATR FT-IR

    Energy Technology Data Exchange (ETDEWEB)

    Emerson, Hilary P. [Florida International Univ., Applied Research Center, Miami, FL (United States); Powell, Brian A. [Clemson Univ., Dept. of Enviromental Engineering and Earth Sciences, Anderson, SC (United States)

    2015-07-01

    Previous studies have shown that mineral surfaces may facilitate the reduction of plutonium though the mechanisms of the reduction are still unknown. The objective of this study is to use batch sorption and attenuated total reflectance Fourier transform infrared spectroscopy experiments to observe the surface-mediated reduction of plutonium on hematite nanoparticles. These techniques allow for in situ measurement of reduction of plutonium with time and may lead to a better understanding of the mechanisms of surface mediated reduction of plutonium. For the first time, ATR FT-IR peaks for Pu(VI) sorbed to hematite are measured at ∝ 916 cm{sup -1}, respectively. The decrease in peak intensity with time provides a real-time, direct measurement of Pu(VI) reduction on the hematite surface. In this work pseudo first order rate constants estimated at the high loadings (22 mg{sub Pu}/g{sub hematite}, 1.34 x 10{sup -6} M{sub Pu}/m{sup 2}) for ATR FT-IR are approximately 10 x slower than at trace concentrations based on previous work. It is proposed that the reduced rate constant at higher Pu loadings occurs after the reduction capacity due to trace Fe(II) has been exhausted and is dependent on the oxidation of water and possibly electron shuttling based on the semiconducting nature of hematite. Therefore, the reduction rate at higher loadings is possibly due to the thermodynamic favorability of Pu(IV)-hydroxide complexes.

  17. Amide resonance and FT-IR spectra of some β-lactam derivatives: application of resolution enhancement procedures in Fourier space

    Science.gov (United States)

    Gil, M.; Plumet, J.; Iza, N.; Morcillo, J.

    1988-05-01

    Fourier Transform infrared (FT-IR) spectra of five 4-acyl-β-lactam derivatives in three organic solvents (carbon tetrachloride, benzene and chloroform) have been registered. Nominal spectral resolution was 1 cm -1 and a Happ-Genzel function was used to apodize the interferograms. Fourier self-deconvolutions were done using standard software based on the algorithm of Kauppinen (1981). The digitalized FT-IR spectra were converted into second and fourth derivatives in Fourier domain using a standard software package supplied for the purpose and based on the technique developed by the N.R.C.C. group. The inherent enhancement resolution of Fourier self-deconvolution and derivatives in Fourier Space have permitted resolution of the characteristic "amide I" bands of the β-lactam ring. The ν(CO) band splitting in the "amide I" region is due to solvent and ring substitution influences on amide resonance and not to H-bonding association. Simultaneous application of both apparent resolution enhancement procedures has allowed us to identify true bands and mathematical artifacts.

  18. A new tridentate Schiff base Cu(II) complex: synthesis, experimental and theoretical studies on its crystal structure, FT-IR and UV-Visible spectra.

    Science.gov (United States)

    Saheb, Vahid; Sheikhshoaie, Iran; Setoodeh, Nasim; Rudbari, Hadi Amiri; Bruno, Giuseppe

    2013-06-01

    A new Cu(II) complex [Cu(L)(NCS)] has been synthesized, using 1-(N-salicylideneimino)-2-(N,N-methyl)-aminoethane as tridentate ONN donor Schiff base ligand (HL). The dark green crystals of the compound are used for single-crystal X-ray analysis and measuring Fourier Transform Infrared (FT-IR) and UV-Visible spectra. Electronic structure calculations at the B3LYP and MP2 levels of theory are performed to optimize the molecular geometry and to calculate the UV-Visible and FT-IR spectra of the compound. Vibrational assignments and analysis of the fundamental modes of the compound are performed. Time-dependent density functional theory (TD-DFT) method is used to calculate the electronic transitions of the complex. A scaling factor of 1.015 is obtained for vibrational frequencies computed at the B3LYP level using basis sets 6-311G(d,p). It is found that solvent has a profound effect on the electronic absorption spectrum. The UV-Visible spectrum of the complex recorded in DMSO and DMF solution can be correctly predicted by a model in which DMSO and DMF molecules are coordinated to the central Cu atom via their oxygen atoms. Copyright © 2013 Elsevier B.V. All rights reserved.

  19. Vibrational spectra (FT-IR, FT-Raman), frontier molecular orbital, first hyperpolarizability, NBO analysis and thermodynamics properties of Piroxicam by HF and DFT methods.

    Science.gov (United States)

    Suresh, S; Gunasekaran, S; Srinivasan, S

    2015-03-05

    The solid phase FT-IR and FT-Raman spectra of 4-Hydroxy-2-methyl-N-(2-pyridinyl)-2H-1,2-benzothiazine-3-carboxamide-1,1-dioxide (Piroxicam) have been recorded in the region 4000-400 and 4000-100cm(-1) respectively. The molecular geometry, harmonic vibrational frequencies and bonding features of piroxicam in the ground state have been calculated by Hartree-Fock (HF) and density functional theory (DFT) methods using 6-311++G(d,p) basis set. The calculated harmonic vibrational frequencies are scaled and they are compared with experimental obtained by FT-IR and FT-Raman spectra. A detailed interpretation of the vibrational spectra of the title compound has been made on the basis of the calculated potential energy distribution (PED). The electronic properties, such as HOMO and LUMO energies, molecular electrostatic potential (MESP) are also performed. The linear polarizability (α) and the first order hyper polarizability (β) values of the title compound have been computed. The molecular stability arising from hyper conjugative interaction, charge delocalization has been analyzed using natural bond orbital (NBO) analysis.

  20. FT-IR spectroscopy and density functional theory calculations of 13C isotopologues of the helical peptide Z-Aib6-OtBu.

    Science.gov (United States)

    Zeko, Timothy; Hannigan, Steven F; Jacisin, Timothy; Guberman-Pfeffer, Matthew J; Falcone, Eric R; Guildford, Melissa J; Szabo, Christopher; Cole, Kathryn E; Placido, Jessica; Daly, Erin; Kubasik, Matthew A

    2014-01-01

    Isotope-edited FT-IR spectroscopy is a combined synthetic and spectroscopic method used to characterize local (e.g., residue-level) vibrational environments of biomolecules. We have prepared the 3(10) helical peptide Z-Aib6-OtBu and seven (13)C-enriched analogues that vary only in the number and position(s) of (13)C═O isotopic enrichment. FT-IR spectra of these eight peptides solvated in the nonpolar aprotic solvent dichloromethane have been collected and compared to frequency, intensity, and normal mode results of DFT calculations. Single (13)C enrichment of amide functional groups tends to localize amide I vibrational eigenmodes, providing residue-specific information regarding the local environment (e.g., hydrogen bonding or solvent exposure) of the peptide bond. Double (13)C enrichment of Z-Aib6-OtBu allows for examination of interamide coupling between two labeled amide functional groups, providing experimental evidence of interamide coupling in the context of 3(10) helical structure. Although the calculated and observed interamide couplings of Z-Aib6-OtBu are a few cm(-1) and less, the eight peptides exhibit distinct infrared spectra, revealing details of interamide coupling and residue level vibrational environments.

  1. Multivariate analysis of attenuated total reflection Fourier transform infrared (ATR FT-IR) spectroscopic data to confirm phase partitioning in methacrylate-based dentin adhesive.

    Science.gov (United States)

    Ye, Qiang; Parthasarathy, Ranganathan; Abedin, Farhana; Laurence, Jennifer S; Misra, Anil; Spencer, Paulette

    2013-12-01

    Water is ubiquitous in the mouths of healthy individuals and is a major interfering factor in the development of a durable seal between the tooth and composite restoration. Water leads to the formation of a variety of defects in dentin adhesives; these defects undermine the tooth-composite bond. Our group recently analyzed phase partitioning of dentin adhesives using high-performance liquid chromatography (HPLC). The concentration measurements provided by HPLC offered a more thorough representation of current adhesive performance and elucidated directions to be taken for further improvement. The sample preparation and instrument analysis using HPLC are, however, time-consuming and labor-intensive. The objective of this work was to develop a methodology for rapid, reliable, and accurate quantitative analysis of near-equilibrium phase partitioning in adhesives exposed to conditions simulating the wet oral environment. Analysis by Fourier transform infrared (FT-IR) spectroscopy in combination with multivariate statistical methods, including partial least squares (PLS) regression and principal component regression (PCR), were used for multivariate calibration to quantify the compositions in separated phases. Excellent predictions were achieved when either the hydrophobic-rich phase or the hydrophilic-rich phase mixtures were analyzed. These results indicate that FT-IR spectroscopy has excellent potential as a rapid method of detection and quantification of dentin adhesives that experience phase separation under conditions that simulate the wet oral environment.

  2. Applications of FT-IR spectroscopy to the studies of esterification and crosslinking of cellulose by polycarboxylic acids: Part II. The performance of the crosslinked cotton fabrics

    Science.gov (United States)

    Wei, Weishu; Yang, Charles Q.

    1998-06-01

    Durable press finishing processes are commonly used in the textile industry to produce wrinkle-free cotton fabrics and garments. A durable press finishing agent forms covalent bands with cellulosic hydroxyl groups, thus crosslinking the cellulose molecules. The crosslinking of cellulose increases wrinkle resistance of the treated cotton fabric and reduces fabric mechanical strength. Wrinkle recovery angle (WRA) and tensile strength are the two most important parameters used to evaluate the performance of the crosslinked cotton fabrics and garments. In this study, we investigated the correlation between WRA and tensile strength on one hand, and the amount of crosslinkages formed by the crosslinking agents including dimethyloldihydroxylethyleneurea (DMDHEU) and 1,2,3,4-butanetetracarboxylic acid (BTCA) determined by FT-IR spectroscopy on the other hand. Linear regression curves between the carbonyl band absorbance, and WRA and tensile strength of the treated cotton fabric were developed. The data indicated that FT-IR spectroscopy is a reliable technique for predicting the performance of durable press finished cotton fabrics, therefore can be used as a convenient instrumental method for quality control in the textile and garment industry.

  3. Type-IV pili spectroscopic markers: applications in the quantification of piliation levels in Moraxella bovis cells by a FT-IR ANN-based model.

    Science.gov (United States)

    Bosch, Alejandra; Prieto, Claudia; Serra, Diego Omar; Martina, Pablo; Stämmbler, Maren; Naumann, Dieter; Schmitt, Jürgen; Yantorno, Osvaldo

    2010-08-01

    Type-IV pili are cell surface organelles found in a wide variety of Gram-negative bacteria. They have traditionally been detected by electron microscopy and ELISA techniques. However, these methodologies are not appropriate for the rapid discrimination and quantification of piliated and nonpiliated cells in industrial or field conditions. Here, the analysis of FT-IR spectra of piliated, nonpiliated and sheared Moraxella bovis cells, together with purified pili suspensions spectra, allowed the identification of 3 IR regions associated to spectroscopic markers of Type-IV pili: 1750-1600, 1450-1350 and 1280-950 cm(-1). Such IR-specific markers were found for piliated cells grown in different culture systems (liquid or solid media), independently of the strain or pili serotype. They were also sensitive to pili expression levels. Therefore, on the bases of these specific spectral features, an FT-IR ANN-based model was developed to classify piliation levels in 5 distinct groups. An overall classification rate of almost 90% demonstrates the strong potential of the ANN system developed to monitor M. bovis cultures in vaccine production.

  4. Vibrational spectra (FT-IR, FT-Raman), frontier molecular orbital, first hyperpolarizability, NBO analysis and thermodynamics properties of Piroxicam by HF and DFT methods

    Science.gov (United States)

    Suresh, S.; Gunasekaran, S.; Srinivasan, S.

    2015-03-01

    The solid phase FT-IR and FT-Raman spectra of 4-Hydroxy-2-methyl-N-(2-pyridinyl)-2H-1,2-benzothiazine-3-carboxamide-1,1-dioxide (Piroxicam) have been recorded in the region 4000-400 and 4000-100 cm-1 respectively. The molecular geometry, harmonic vibrational frequencies and bonding features of piroxicam in the ground state have been calculated by Hartree-Fock (HF) and density functional theory (DFT) methods using 6-311++G(d,p) basis set. The calculated harmonic vibrational frequencies are scaled and they are compared with experimental obtained by FT-IR and FT-Raman spectra. A detailed interpretation of the vibrational spectra of the title compound has been made on the basis of the calculated potential energy distribution (PED). The electronic properties, such as HOMO and LUMO energies, molecular electrostatic potential (MESP) are also performed. The linear polarizability (α) and the first order hyper polarizability (β) values of the title compound have been computed. The molecular stability arising from hyper conjugative interaction, charge delocalization has been analyzed using natural bond orbital (NBO) analysis.

  5. A Raman scattering and FT-IR spectroscopic study on the effect of the solar radiation in Antarctica on bovine cornea

    Science.gov (United States)

    Yamamoto, Tatsuyuki; Murakami, Naoki; Yoshikiyo, Keisuke; Takahashi, Tetsuya; Yamamoto, Naoyuki

    2010-01-01

    The Raman scattering and FT-IR spectra of the corneas, transported to the Syowa station in Antarctica and exposed to the solar radiation of the mid-summer for four weeks, were studied to reveal that type IV collagen involved in corneas were fragmented. The amide I and III Raman bands were observed at 1660 and 1245 cm -1, respectively, and the amide I and II infrared bands were observed at 1655 and 1545 cm -1, respectively, for original corneas before exposure. The background of Raman signals prominently increased and the ratio of amide II infrared band versus amide I decreased by the solar radiation in Antarctica. The control experiment using an artificial UV lamp was also performed in laboratory. The decline rate of the amide II/amide I was utilized for estimating the degree of fragmentation of collagen, to reveal that the addition of vitamin C suppressed the reaction while the addition of sugars promoted it. The effect of the solar radiation in Antarctica on the corneas was estimated as the same as the artificial UV lamp of four weeks (Raman) or one week (FT-IR) exposure.

  6. Identification of Quercus agrifolia (coast live oak resistant to the invasive pathogen Phytophthora ramorum in native stands using Fourier-transform infrared (FT-IR spectroscopy

    Directory of Open Access Journals (Sweden)

    Anna Olivia Conrad

    2014-10-01

    Full Text Available Over the last two decades coast live oak (CLO dominance in many California coastal ecosystems has been threatened by the alien invasive pathogen Phytophthora ramorum, the causal agent of sudden oak death. In spite of high infection and mortality rates in some areas, the presence of apparently resistant trees has been observed, including trees that become infected but recover over time. However, identifying resistant trees based on recovery alone can take many years. The objective of this study was to determine if Fourier-transform infrared (FT-IR spectroscopy, a chemical fingerprinting technique, can be used to identify CLO resistant to P. ramorum prior to infection. Soft independent modeling of class analogy identified spectral regions that differed between resistant and susceptible trees. Regions most useful for discrimination were associated with carbonyl group vibrations. Additionally, concentrations of two putative phenolic biomarkers of resistance were predicted using partial least squares regression; > 99% of the variation was explained by this analysis. This study demonstrates that chemical fingerprinting can be used to identify resistance in a natural population of forest trees prior to infection with a pathogen. FT-IR spectroscopy may be a useful approach for managing forests impacted by sudden oak death, as well as in other situations where emerging or existing forest pests and diseases are of concern.

  7. 1H NMR and FT-IR dataset based structural investigation of poly(amic acid)s and polyimides from 4,4′-diaminostilbene

    Science.gov (United States)

    Kumar, Amit; Tateyama, Seiji; Yasaki, Katsuaki; Ali, Mohammad Asif; Takaya, Naoki; Singh, Rajeev; Kaneko, Tatsuo

    2016-01-01

    Structural investigation of polymers by various available analytical methods is important in order to correlate the structure with polymer properties for which understanding of polymer structure is very important factor. The data presented here in this article shows the 1H NMR spectra used for the characterization of prepared poly(amic acid)s (PAAs). It is often difficult to assigns the peak in NMR of polymers due to its complexity. Data presented here helps in assigning the proton peak in complex NMR of PAAs prepared from aromatic diamines. Further functionality in polymer chains can be confirmed by FT-IR spectra. Change in functionality during some reaction or process can be monitored by disappearance or appearance of peaks in FT-IR. The complete imidization of PAAs to Polyimides (PIs) is difficult to analyze because of the chemical stability i.e. insolubility of PIs in most of the solvent therefore the completion of imidization process was confirmed using FTIR. PMID:26933669

  8. Application of spectroscopic methods for identification (FT-IR, Raman spectroscopy) and determination (UV, EPR) of quercetin-3-O-rutinoside. Experimental and DFT based approach

    Science.gov (United States)

    Paczkowska, Magdalena; Lewandowska, Kornelia; Bednarski, Waldemar; Mizera, Mikołaj; Podborska, Agnieszka; Krause, Anna; Cielecka-Piontek, Judyta

    2015-04-01

    Vibrational (FT-IR, Raman) and electronic (UV, EPR) spectral measurements were performed for an analysis of rutin (quercetin-3-O-rutinoside) obtained from Rutaofficinalis. The identification of rutin was done with the use of FT-IR and Raman spectra. Those experimental spectra were determined with the support of theoretical calculations based on a DFT method with the B3LYP hybrid functional and 6-31G(d,p) basis set. The application of UV and EPR spectra was found to be a suitable analytical approach to the evaluation of changes in rutin exposed to certain physicochemical factors. Differences in absorbance observed in direct UV spectra were used to monitor changes in the concentration of rutin in degraded samples. Spectra of electron paramagnetic resonance allowed studying the process of free-radical quenching in rutin following its exposure to light. The molecular electrostatic potential (MEP) and frontier molecular orbitals (LUMO-HOMO) were also determined in order to predict structural changes and reactive sites in rutin.

  9. FT-IR and thermoluminescence investigation of P{sub 2}O{sub 5}-BaO-K{sub 2}O glass system

    Energy Technology Data Exchange (ETDEWEB)

    Ivascu, C. [Babes-Bolyai University, Faculty of Physics, Kogalniceanu 1, 400084 Cluj Napoca (Romania); Timar-Gabor, A. [Babes-Bolyai University, Faculty of Environmental Science, Fantanele 30, 400294 Cluj Napoca (Romania); Cozar, O. [Babes-Bolyai University, Faculty of Physics, Kogalniceanu 1, 400084 Cluj Napoca, Romania and Academy of Romanian Scientists, Splaiul Independentei 54, 050094, Bucharest (Romania)

    2013-11-13

    The 0.5P{sub 2}O{sub 5}⋅xBaO⋅(0.5−x)K{sub 2}O glass system (0≤x≤0.5mol%) is investigated by FT-IR and thermoluminescence as a possible dosimetic material. FT-IR spectra show structural network modifications with the composition variations of the studied glasses. The predominant absorption bands are characterized by two broad peaks near 500 cm{sup −1}, two weak peaks around 740 cm{sup −1} and three peaks in the 900–1270 cm{sup −1} region. The shift in the position of the band assigned to asymmetric stretching of PO{sub 2}{sup −} group, υ{sub as}(PO{sub 2}{sup −}) modes from ∼1100 cm{sup −1} to 1085 cm{sup −1} and the decrease in its relative intensity with the increasing of K{sub 2}O content shows a network modifier role of this oxide.. Luminescence investigations show that by adding modifier oxides in the phosphate glass a dose dependent TL signals result upon irradiation. Thus P{sub 2}O{sub 5}–BaO–K{sub 2}O glass system is a possible candidate material for dosimetry in the dose 0 – 50 Gy range.

  10. Structure analysis and spectroscopic characterization of 2-Fluoro-3-Methylpyridine-5-Boronic Acid with experimental (FT-IR, Raman, NMR and XRD) techniques and quantum chemical calculations

    Science.gov (United States)

    Alver, Özgür; Dikmen, Gökhan

    2016-03-01

    Possible stable conformers, geometrical molecular structures, vibrational properties as well as band assignments, nuclear magnetic shielding tensors of 2-Fluoro-3-Methylpyridine-5-Boronic Acid (2F3MP5BA) were studied experimentally and theoretically using FT-IR, Raman, (CP/MAS) NMR and XRD spectroscopic methods. FT-IR and Raman spectra were evaluated in the region of 3500-400 cm-1, and 3200-400 cm-1, respectively. The optimized geometric structures, vibrational wavenumbers and nuclear magnetic shielding tensors were examined using Becke-3-Lee-Yang-Parr (B3LYP) hybrid density functional theory method with 6-311++G(d, p) basis set. 1H, 13C NMR chemical shifts were calculated using the gauge invariant atomic orbital (GIAO) method. 1H, 13C, APT and HETCOR NMR experiments of title molecule were carried out in DMSO solution. 13C CP/MAS NMR measurement was done with 4 mm zirconium rotor and glycine was used as an external standard. Single crystal of 2F3MP5BA was also prepared for XRD measurements. Assignments of vibrational wavenumbers were also strengthened by calculating the total energy distribution (TED) values using scaled quantum mechanical (SQM) method.

  11. Spectroscopic characteristic (FT-IR, FT-Raman, UV, 1H and 13C NMR), theoretical calculations and biological activity of alkali metal homovanillates

    Science.gov (United States)

    Samsonowicz, M.; Kowczyk-Sadowy, M.; Piekut, J.; Regulska, E.; Lewandowski, W.

    2016-04-01

    The structural and vibrational properties of lithium, sodium, potassium, rubidium and cesium homovanillates were investigated in this paper. Supplementary molecular spectroscopic methods such as: FT-IR, FT-Raman in the solid phase, UV and NMR were applied. The geometrical parameters and energies were obtained from density functional theory (DFT) B3LYP method with 6-311++G** basis set calculations. The geometry of the molecule was fully optimized, vibrational spectra were calculated and fundamental vibrations were assigned. Geometric and magnetic aromaticity indices, atomic charges, dipole moments, HOMO and LUMO energies were also calculated. The microbial activity of investigated compounds was tested against Bacillus subtilis (BS), Pseudomonas aeruginosa (PA), Escherichia coli (EC), Staphylococcus aureus (SA) and Candida albicans (CA). The relationship between the molecular structure of tested compounds and their antimicrobial activity was studied. The principal component analysis (PCA) was applied in order to attempt to distinguish the biological activities of these compounds according to selected band wavenumbers. Obtained data show that the FT-IR spectra can be a rapid and reliable analytical tool and a good source of information for the quantitative analysis of the relationship between the molecular structure of the compound and its biological activity.

  12. Caracterização por FT-IR da superfície de borracha EPDM tratada via plasma por micro-ondas

    Directory of Open Access Journals (Sweden)

    Renata P. dos Santos

    2012-01-01

    Full Text Available A superfície de uma borracha de etileno-propileno-dieno (EPDM vulcanizada foi modificada via plasma por microondas, com gases Ar, Ar/O2, N2/O2 e N2/H2, tendo como objetivo melhorar as propriedades adesivas da superfície. A técnica FT-IR/UATR foi escolhida para caracterizar as superfícies após tratamento, pois apresentou menor interferência dos ingredientes da formulação da EPDM, dentre as técnicas analisadas (ATR/KRS-5 e Ge. Grupos oxigenados foram inseridos na superfície da amostra tratada, mesmo quando não foi utilizado o oxigênio, pois estes grupos foram formados quando a superfície ativada foi exposta à atmosfera. Já em tratamentos contendo N2, grupos oxigenados e possíveis grupos nitrogenados foram identificados por FT-IR. Redução nos valores do ângulo de contato, aumento no trabalho de adesão e aumento no ensaio de resistência ao descascamento (EPDM × Poliuretano foram observados após tratamento com Ar e N2/H2, resultando em melhora nas propriedades adesivas da superfície tratada.

  13. Implementation of time-resolved step-scan fourier transform infrared (FT-IR) spectroscopy using a kHz repetition rate pump laser.

    Science.gov (United States)

    Magana, Donny; Parul, Dzmitry; Dyer, R Brian; Shreve, Andrew P

    2011-05-01

    Time-resolved step-scan Fourier transform infrared (FT-IR) spectroscopy has been shown to be invaluable for studying excited-state structures and dynamics in both biological and inorganic systems. Despite the established utility of this method, technical challenges continue to limit the data quality and more wide ranging applications. A critical problem has been the low laser repetition rate and interferometer stepping rate (both are typically 10 Hz) used for data acquisition. Here we demonstrate significant improvement in the quality of time-resolved spectra through the use of a kHz repetition rate laser to achieve kHz excitation and data collection rates while stepping the spectrometer at 200 Hz. We have studied the metal-to-ligand charge transfer excited state of Ru(bipyridine)(3)Cl(2) in deuterated acetonitrile to test and optimize high repetition rate data collection. Comparison of different interferometer stepping rates reveals an optimum rate of 200 Hz due to minimization of long-term baseline drift. With the improved collection efficiency and signal-to-noise ratio, better assignments of the MLCT excited-state bands can be made. Using optimized parameters, carbonmonoxy myoglobin in deuterated buffer is also studied by observing the infrared signatures of carbon monoxide photolysis upon excitation of the heme. We conclude from these studies that a substantial increase in performance of ss-FT-IR instrumentation is achieved by coupling commercial infrared benches with kHz repetition rate lasers.

  14. Synchrotron FT-IR analyses of microstructured biomineral domains: Hints to the biomineralization processes in freshwater cultured pearls.

    Science.gov (United States)

    Soldati, A. L.; Vicente-Vilas, V.; Gasharova, B.; Jacob, D. E.

    2009-04-01

    Recent investigations in freshwater cultured pearls (bio-carbonate) by micro-Raman spectroscopy (Wehrmeister et al., 2008; Soldati et al., 2008), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) imaging (Jacob et al., 2008) show that the pearl biomineralisation starts with a self assembling process in which an existing gel matrix of amorphous calcium carbonate (ACC) and organic substances reorganizes and conglomerates in small domains; these conglomerates then form prisms and mature nacreous tablets of aragonite or vaterite. Raman spectroscopy shows that the calcium carbonate polymorphs have decreasing luminescence in the order ACC>Vaterite>Aragonite, coinciding with decreasing quantities of S and P (related to the organic matrix) measured by Laser Ablation Inductively Coupled Plasma Mass Spectroscopy (LA-ICP-MS) and Electron Probe Micro Analyzer (EPMA). Although little is known about the process of transformation of the ACC gel into vaterite and aragonite, it is speculated that this probably involves dehydration and change of the accompanying organic matrix. This is also supported by our laboratory FT-IR analysis. However, due to the small size of the areas of ACC (about 10 ?m) and the biogenic crystals an in-situ high spatially resolved IR-method is needed to record how the water content and organic matrix change in the biomineralisation sequence, to understand which processes take place in the self-organization. The beamline IR-1 at the ANKA synchrotron source (Karlsruhe, Germany) was used for this experiment. Freshwater cultured pearls from China cultured in Hyriopsis cumingii mussels by tissue nucleation methods (so-called beadless pearls) as well as by bead implantation methods (aragonite nucleus) were studied. The pearls were cut in half with a diamond-plated saw and polished with diamond paste on a copper plate. Micro-Raman spectroscopy maps (Department of Geosciences, at the Johannes Gutenberg-University, Mainz) were generated

  15. Spectroscopic [FT-IR and FT-Raman] and molecular modeling (MM) study of benzene sulfonamide molecule using quantum chemical calculations

    Science.gov (United States)

    Vinod, K. S.; Periandy, S.; Govindarajan, M.

    2016-07-01

    The spectroscopic and molecular modeling (MM) study includes, FT-IR, FT-Raman and 13C NMR and 1H NMR spectra of the Benzene sulfonamide were recorded for the analysis. The observed experimental and theoretical frequencies (IR and Raman) were assigned according to their distinctive region. The present study of this title molecule have been carried out by hybrid computational calculations of HF and DFT (B3LYP) methods with 6-311+G(d,p) and 6-311++G(d,p) basis sets and the corresponding results are tabulated. The structural modifications of the compound due to the substitutions of NH2 and SO2 were investigated. The minimum energy conformers of the compound were studied using conformational analysis. The alternations of the vibrational pattern of the base structure related to the substitutions were analyzed. The thermodynamic parameters (such as zero-point vibrational energy, thermal energy, specific heat capacity, rotational constants, entropy, and dipole moment) of Benzene sulfonamide have been calculated. The donor acceptor interactions of the compound and the corresponding UV transitions are found out using NBO analysis. The NMR spectra were simulated by using the gauge independent atomic orbital (GIAO) method with B3LYP methods and the 6-311++G(d,p) basis set and their spectra were simulated and the chemical shifts related to TMS were compared. A quantum computational study on the electronic and optical properties absorption wavelengths, excitation energy, dipole moment and frontier molecular orbital energies, were performed by HF and DFT methods. The energy gap of the present compound was calculated related to HOMO and LUMO energies which confirm the occurring of charge transformation between the base and ligand group. Besides frontier molecular orbitals (FMO), molecular electrostatic potential (MEP) was performed. The thermodynamic properties (heat capacity, entropy, and enthalpy) of the title compound at different temperatures were calculated in gas phase and

  16. Characterization of prepared In2O3 thin films: The FT-IR, FT-Raman, UV-Visible investigation and optical analysis

    Science.gov (United States)

    Panneerdoss, I. Joseph; Jeyakumar, S. Johnson; Ramalingam, S.; Jothibas, M.

    2015-08-01

    In this original work, the Indium oxide (In2O3) thin film is deposited cleanly on microscope glass substrate at different temperatures by spray pyrolysis technique. The physical properties of the films are characterized by XRD, SEM, AFM and AFM measurements. The spectroscopic investigation has been carried out on the results of FT-IR, FT-Raman and UV-Visible. XRD analysis exposed that the structural transformation of films from stoichiometric to non-stoichiometric orientation of the plane vice versa and also found that, the film is polycrystalline in nature having cubic crystal structure with a preferred grain orientation along (2 2 2) plane. SEM and AFM studies revealed that, the film with 0.1 M at 500 °C has spherical grains with uniform dimension. The complete vibrational analysis has been carried out and the optimized parameters are calculated using HF and DFT (CAM-B3LYP, B3LYP and B3PW91) methods with 3-21G(d,p) basis set. Furthermore, NMR chemical shifts are calculated by using the gauge independent atomic orbital (GIAO) technique. The molecular electronic properties; absorption wavelengths, excitation energy, dipole moment and frontier molecular orbital energies, molecular electrostatic potential energy (MEP) analysis and Polarizability first order hyperpolarizability calculations are performed by time dependent DFT (TD-DFT) approach. The energy excitation on electronic structure is investigated and the assignment of the absorption bands in the electronic spectra of steady compound is discussed. The calculated HOMO and LUMO energies showed the enhancement of energy gap by the addition of substitutions with the base molecule. The thermodynamic properties (heat capacity, entropy, and enthalpy) at different temperatures are calculated and interpreted in gas phase.

  17. FT-IR, FT-Raman, NMR and UV-Vis spectra and DFT calculations of 5-bromo-2-ethoxyphenylboronic acid (monomer and dimer structures).

    Science.gov (United States)

    Sas, E B; Kose, E; Kurt, M; Karabacak, M

    2015-02-25

    In this study, the Fourier Transform Infrared (FT-IR) and Fourier Transform Raman (FT-Raman) spectra of 5-bromo-2-ethoxyphenylboronic acid (5Br2EPBA) are recorded in the solid phase in the region 4000-400 cm(-1) and 3500-10 cm(-1), respectively. The (1)H, (13)C and DEPT nuclear magnetic resonance (NMR) spectra are recorded in DMSO solution. The UV-Vis absorption spectrum of 5Br2EPBA is saved in the range of 200-400 nm in ethanol and water. The following theoretical calculations for monomeric and dimeric structures are supported by experimental results. The molecular geometry and vibrational frequencies in the ground state are calculated by using DFT methods with 6-31G(d,p) and 6-311G(d,p) basis sets. There are four conformers for the present molecule. The computational results diagnose the most stable conformer of 5Br2EPBA as Trans-Cis (TC) form. The complete assignments are performed on the basis of the total energy distribution (TED) of vibrational modes, calculated with scaled quantum mechanics (SQM) method in parallel quantum solutions (PQS) program. The (1)H and (13)C NMR chemical shifts of 5Br2EPBA molecule are calculated by using the Gauge Invariant Atomic Orbital (GIAO) method in DMSO and gas phase for monomer and dimer structures of the most stable conformer. Moreover, electronic properties, such as the HOMO and LUMO energies (by TD-DFT and CIS methods) and molecular electrostatic potential surface (MEPs) are investigated. Stability of the molecule arising from hyper-conjugative interactions, charge delocalization is analyzed using natural bond orbital (NBO) analysis. Nonlinear optical (NLO) properties and thermodynamic features are presented. All calculated results are compared with the experimental data of the title molecule. The correlation of theoretical and experimental results provides a detailed description of the structural and physicochemical properties of the title molecule.

  18. Caracterização de um pré-impregnado aeronáutico por FT-IR e análise térmica Characterization of pre-impregnated of epoxy resin/carbon fiber

    Directory of Open Access Journals (Sweden)

    Vanesa C. G. M. Ferrari

    2012-01-01

    Full Text Available Este trabalho consiste na caracterização de um pré-impregnado ("prepreg" de resina epoxídica/fibra de carbono, usando-se espectroscopia no infravermelho com transformada de Fourier (FT-IR, análise termogravimétrica (TG, calorimetria exploratória diferencial (DSC e análise térmica dinâmico-mecânica (DMTA. A análise por FT-IR foi realizada nos modos de transmissão (pastilha de KBr, pirólise em bico de Bunsen e controlada e detecção fotoacústica (PAS. Os espectros de FT-IR de transmissão revelaram a presença de resina epoxídica, grupos ciano, amínicos e bisfenol A, que possibilitaram identificar o provável agente de cura:a cianoguanidina (ou dicianodiamida do sistema epoxídico. Os espectros de FT-IR/PAS permitiram acompanhar as alterações espectrométricas causadas pela cura. A análise térmica auxiliou na observação e compreensão dos eventos durante o processo de cura, etapas de gelificação e vitrificação, e da influência destas nas temperaturas de transição vítrea (Tg do material curado e na escolha do intervalo de temperatura de cura, que é um dos parâmetros mais importantes do processo produtivo.This work explores the characterization of pre-impregnated ("prepreg" materials made with an epoxy resin/carbon fiber, using FT-IR spectroscopy, thermogravimetry (TG, differential scanning calorimetry (DSC and dynamic mechanical thermal analysis (DMTA. FT-IR spectroscopy was used in the transmission mode (KBr pellets, pyrolysis without control and controlled pyrolysis and photoacoustic detection (FT-IR/PAS. The transmission FT-IR spectra revealed the presence of epoxy resin, cyano groups, amine and bisphenol A, which allowed us to identify the probable agent of cure: cyanoguanidine (or DCD. With FT-IR/PAS it was possible to monitor spectrometric changes caused by curing. The thermal analysis assisted in observing and understanding events during the curing process, including the gelation and vitrification steps. It

  19. Tuning the composition and magnetostructure of dysprosium iron garnets by Co-substitution: An XRD, FT-IR, XPS and VSM study

    Energy Technology Data Exchange (ETDEWEB)

    Tholkappiyan, R.; Vishista, K., E-mail: raovishista@gmail.com

    2015-10-01

    Graphical abstract: - Highlights: • Garnet type Dy{sub 3}Fe{sub 5−x}Co{sub x}O{sub 12} (x = 0–0.06) nanoparticles were synthesized by glycine assisted combustion method. • To investigate and confirm the phases in the synthesized ferrite nanoparticles by FT-IR and XRD analysis. • To investigate the compositional and oxidation state of the samples by X-ray photoelectron spectroscopy. • The detailed core level spectra of Dy 4d, Fe 2p, Co 2p and O 1s were analyzed using XPS. • The magnetic property was studied by VSM technique. - Abstract: We report the Co-substituting on the synthesis and properties of garnet type dysprosium ferrite nanoparticles by basic composition Dy{sub 3}Fe{sub 5−x}Co{sub x}O{sub 12} (x = 0–0.06) synthesized through glycine assisted combustion method. A possible formation mechanism of synthesized Dy{sub 3}Fe{sub 5−x}Co{sub x}O{sub 12} samples by controlling the synthesis process has been proposed. XRD, FT-IR, XPS and VSM studies were used to investigate the compositional and magnetostructural properties of the prepared nanoparticles. XRD results confirm that all the samples are single-phase cubic garnet structure with mean crystallite size of 97–105 nm obtained from Scherrer method and 95–102 nm from W–H method. FT-IR analysis shows the presence of three expected bands in the frequency limit of 450–600 cm{sup −1} attributed to metal–O stretching vibration in tetrahedral site of garnet structure. A typical survey spectrum from XPS results confirmed the presence of Dy, Fe, Co and O elements in the samples. This study also to characterize the different oxidation states of the samples by fitting the parameters of high resolution Dy 4d, Fe 2p, Co 2p and O 1s XPS spectra. The XPS data of Dy 4d spectrum show that Dy{sup 3+} ion occupy in dodecahedral (D) site. The XPS analysis of Fe 2p and Co 2p data suggests that (Fe{sup 3+} and Fe{sup 2+}), (Co{sup 3+} and Co{sup 2+}) are distributed in tetrahedral and octahedral sites

  20. Principles, performance, and applications of spectral reconstitution (SR) in quantitative analysis of oils by Fourier transform infrared spectroscopy (FT-IR).

    Science.gov (United States)

    García-González, Diego L; Sedman, Jacqueline; van de Voort, Frederik R

    2013-04-01

    Spectral reconstitution (SR) is a dilution technique developed to facilitate the rapid, automated, and quantitative analysis of viscous oil samples by Fourier transform infrared spectroscopy (FT-IR). This technique involves determining the dilution factor through measurement of an absorption band of a suitable spectral marker added to the diluent, and then spectrally removing the diluent from the sample and multiplying the resulting spectrum to compensate for the effect of dilution on the band intensities. The facsimile spectrum of the neat oil thus obtained can then be qualitatively or quantitatively analyzed for the parameter(s) of interest. The quantitative performance of the SR technique was examined with two transition-metal carbonyl complexes as spectral markers, chromium hexacarbonyl and methylcyclopentadienyl manganese tricarbonyl. The estimation of the volume fraction (VF) of the diluent in a model system, consisting of canola oil diluted to various extents with odorless mineral spirits, served as the basis for assessment of these markers. The relationship between the VF estimates and the true volume fraction (VF(t)) was found to be strongly dependent on the dilution ratio and also depended, to a lesser extent, on the spectral resolution. These dependences are attributable to the effect of changes in matrix polarity on the bandwidth of the ν(CO) marker bands. Excellent VF(t) estimates were obtained by making a polarity correction devised with a variance-spectrum-delineated correction equation. In the absence of such a correction, SR was shown to introduce only a minor and constant bias, provided that polarity differences among all the diluted samples analyzed were minimal. This bias can be built into the calibration of a quantitative FT-IR analytical method by subjecting appropriate calibration standards to the same SR procedure as the samples to be analyzed. The primary purpose of the SR technique is to simplify preparation of diluted samples such that

  1. FT-IR studies on the conformation and effective head-group area of AOT molecules in W/O microemulsions

    Institute of Scientific and Technical Information of China (English)

    周国伟; 鲍猛; 李干佐; 陈文君

    2002-01-01

    Using Fourier transform infrared(FT-IR) spectroscopy technique, the carbonyl stretching vibration bands of AOT in sodium bis(2-ethylhexyl)sulfosuccinate (AOT)/isooctane/water reverse (W/O) microemulsions system have been investigated by least square curve fitting. The results indicate that an asymmetric adsorbed peak of carbonyl stretching vibration of AOT molecule is situated in (1739 ± 1) and (1725 ± 2) cm-1. The two peaks correspond to different carbonyls in gauche conformation and trans conformation of AOT molecules, respectively. With different water contents (W0), the variations of peak intensity ratio (/= l1739/l1725) reflect the change of the ratio for the two conformation populations and the variations of the effective head-group area of AOT molecule have relations to the ratio of two conformation populations.

  2. Effect of storage on microstructural changes of Carbopol polymers tracked by the combination of positron annihilation lifetime spectroscopy and FT-IR spectroscopy.

    Science.gov (United States)

    Szabó, Barnabás; Süvegh, Károly; Zelkó, Romána

    2011-09-15

    Different types of Carbopols are frequently applied excipients of various dosage forms. Depending on the supramolecular structure, their water sorption behaviour could significantly differ. The purpose of the present study was to track the supramolecular changes of two types of Carbopol polymers (Carbopol 71G and Ultrez 10NF) alone and in their physical mixture with a water-soluble drug, vitamin B(12), as a function of storage time. The combination of FT-IR spectroscopy, positron annihilation lifetime spectroscopy (PALS) and Doppler-broadening spectroscopy was applied to follow the effect of water uptake on the structural changes. Our results indicate that water-induced interactions between polymeric chains can be sensitively detected. This enables the prediction of stability of dosage forms in the course of storage.

  3. Spectroscopy (FT-IR, FT-Raman), hydrogen bonding, electrostatic potential and HOMO-LUMO analysis of tioxolone based on DFT calculations

    Science.gov (United States)

    Tao, Yaping; Li, Xiaofeng; Han, Ligang; Zhang, Weiying; Liu, Zhaojun

    2016-10-01

    Tioxolone possess antipsoriatic and antibacterial properties. Therefore, it has been used in treating various skin and scalp disorders for many years. Spectroscopic analysis of tioxolone was presented by using density functional theory (DFT) calculations and experiments (FT-IR, FT-Raman and UV-Vis). Molecular geometry and vibrational wavenumbers of tioxolone were investigated by using B3LYP method with aug-cc-pVTZ basis set. A complete vibrational spectra was made to analyze the potential energy distributions (PED). In addition, analysis of frontier molecular orbitals, electrostatic potential (ESP) and thermodynamic properties (heat capacity, entropy, enthalpy and Gibbs free energy) was presented with the same basis-set. Furthermore, the nature of molecular association through hydrogen bonding were discussed using atoms in molecules (AIM) and reduced density gradient (RDG) methods.

  4. Conversion of Natural Aldehydes from Eucalyptus citriodora, Cymbopogon citratus, and Lippia multiflora into Oximes: GC-MS and FT-IR Analysis †

    Directory of Open Access Journals (Sweden)

    Igor W. Ouédraogo

    2009-08-01

    Full Text Available Three carbonyl-containing extracts of essential oils from Eucalyptus citriodora (Myrtaceae, Cymbopogon citratus (Gramineae and Lippia multiflora (Verbenaceae were used for the preparation of oximes. The reaction mixtures were analyzed by GC-MS and different compounds were identified on the basis of their retention times and mass spectra. We observed quantitative conversion of aldehydes to their corresponding oximes with a purity of 95 to 99%. E and Z stereoisomers of the oximes were obtained and separated by GC-MS. During GC analysis, the high temperature in the injector was shown to cause partial dehydratation of oximes and the resulting nitriles were readily identified. Based on FT-IR spectroscopy, that revealed the high stability and low volatility of these compounds, the so-obtained oximes could be useful for future biological studies.

  5. FT-IR studies on the conformation and effective head-group area of AOT molecules in W/O microemulsions

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Using Fourier transform infrared(FT-IR) spectroscopy technique, the carbonyl stretching vibration bands of AOT in sodium bis(2-ethylhexyl)sulfosuccinate(AOT)/isooctane/water reverse(W/O) microemulsions system have been investigated by least square curve fitting. The results indicate that an asymmetric adsorbed peak of carbonyl stretching vibration of AOT molecule is situated in(1739 ± 1) and(1725 ± 2) cm-1. The two peaks correspond to different carbonyls in gau-che conformation and trans conformation of AOT molecules, respectively. With different water contents(W0), the variations of peak intensity ratio(Ir1 = I1739/I1725) reflect the change of the ratio for the two conformation populations and the variations of the effective head-group area of AOT mo-lecule have relations to the ratio of two conformation populations.

  6. Density functional theory study, FT-IR and FT-Raman spectra and SQM force field calculation for vibrational analysis of 1, 3-Bis (hydroxymethyl) benzimidazolin-2-one.

    Science.gov (United States)

    Joseph, Lynnette; Sajan, D; Chaitanya, K; Devarajegowda, H C; Isac, Jayakumary

    2013-10-01

    FT-IR and FT-Raman spectra of 1, 3-Bis (hydroxymethyl) benzimidazolin-2-one were recorded and analyzed in the solid phase. The optimized molecular geometry and vibrational wavenumbers have also been calculated in optimized structure by using DFT method. Scaled quantum mechanical force fields have also been used to calculate potential energy distributions in order to make conspicuous vibrational assignments. The red shifting of the O-H stretching wavenumber is due to the formation of O-H···O intermolecular hydrogen bonding. The lowering and splitting of the carbonyl stretching vibrational modes is assigned to the intermolecular association based on C=O···H type hydrogen bonding in the molecule. Chemical interpretation of hyperconjugative interactions was done by natural bond orbital analysis.

  7. Poly-3-hydroxy butyric acid interaction with the transgenic flax fibers: FT-IR and Raman spectra of the composite extracted from a GM flax

    Science.gov (United States)

    Wróbel-Kwiatkowska, Magdalena; Żuk, Magdalena; Szopa, Jan; Dymińska, Lucyna; Mączka, Mirosław; Hanuza, Jerzy

    2009-07-01

    The FT-IR and FT-Raman studies have been performed on commercial 3-hydroxy-butyric acid, commercial poly-3-hydroxy butyric acid as well as poly-3-hydroxy butyric acid (PHB) produced by bacteria. The data were compared to those obtained for poly-3-hydroxy butyric acid extracted from natural and genetically modified flax. Genetically modified flax was generated by expression of three bacterial genes coding for synthesis of poly-3-hydroxy butyric acid. Thus transgenic flaxes were enhanced with different amount of the PHB. The discussion of polymer structure and vibrational properties has been done in order to get insight into differences among these materials. The interaction between the cellulose of flax fibers and embedded poly-3-hydroxybutyric acid has been also discussed. The spectroscopic data provide evidences for structural changes in cellulose and in PHB when synthesized in fibers. Based on this data it is suggesting that cellulose and PHB interact by hydrogen and ester bonds.

  8. X-ray, FT-IR, NMR and PM5 structural studies and antibacterial activity of unexpectedly stable salinomycin-benzotriazole intermediate ester

    Science.gov (United States)

    Huczyński, Adam; Janczak, Jan; Antoszczak, Michał; Stefańska, Joanna; Brzezinski, Bogumil

    2012-08-01

    The unexpectedly stable benzotriazole ester of salinomycin (SAL-HOBt) - an intermediate product of the amidation reaction of salinomycin has been isolated and structurally characterised (using a single crystal) by X-ray, FT-IR, NMR and semiempirical methods. The results of the X-ray and spectroscopic studies demonstrated that this intermediate ester exist in the solid state and in solution exclusively as the stable O-acyl form. The molecular structure of SAL-HOBt is stabilised by relatively weak intramolecular hydrogen bonds. The PM5 calculation of possible structures of SAL-HOBt has shown that the O-acyl form is more energetically favourable than its N-oxide-N-acyl isomers. The antimicrobial tests show that SAL-HOBt is active against Gram-positive bacteria and clinical isolates methicillin-resistant Staphylococcus aureus (MIC = 1-2 μg/ml).

  9. Vibrational spectroscopic (FT-IR, FT-Raman) studies, Hirshfeld surfaces analysis, and quantum chemical calculations of m-acetotoluidide and m-thioacetotoluidide

    Science.gov (United States)

    Śmiszek-Lindert, Wioleta Edyta; Chełmecka, Elżbieta; Góralczyk, Stefan; Kaczmarek, Marian

    2017-01-01

    Theoretical calculations of the m-acetotoluidide and m-thioacetotoluidide isolated molecules were performed by using density functional theory (DFT) method at B3LYP/6-311++G (d,p) and B3LYP/6-311++G (3df,2pd) basis set levels. The Hirshfeld surfaces analysis and FT-IR and FT-Raman spectroscopy studies have been reported. The geometrical parameters of the title amide and thioamide are in a good agreement with the XRD experiment. The vibrational frequencies were calculated and scaled, and subsequently values have been compared with the experimental Infrared and Raman spectra. The observed and calculated frequencies are found to be in good agreement. The analysis of the Hirshfeld surface has been well correlated to the spectroscopic studies. Additionally, the highest occupied molecular orbital energy (EHOMO), lowest unoccupied molecular orbital energy (ELUMO) and the energy gap between EHOMO and ELUMO (ΔEHOMO-LUMO) have been calculated.

  10. Structural study, NCA, FT-IR, FT-Raman spectral investigations, NBO analysis, thermodynamic functions of N-acetyl-L-phenylalanine

    Science.gov (United States)

    Raja, B.; Balachandran, V.; Revathi, B.

    2015-03-01

    The FT-IR and FT-Raman spectra of N-acetyl-L-phenylalanine were recorded and analyzed. Natural bond orbital analysis has been carried out for various intramolecular interactions that are responsible for the stabilization of the molecule. HOMO-LUMO energy gap has been computed with the help of density functional theory. The statistical thermodynamic functions (heat capacity, entropy, vibrational partition function and Gibbs energy) were obtained for the range of temperature 100-1000 K. The polarizability, first hyperpolarizability, anisotropy polarizability invariant has been computed using quantum chemical calculations. The infrared and Raman spectra were also predicted from the calculated intensities. Comparison of the experimental and theoretical spectra values provides important information about the ability of the computational method to describe the vibrational modes.

  11. FT-IR spectroscopy, scanning electron microscopy and porosity measurements to determine the firing temperature of ancient megalithic period potteries excavated at Adichanallur in Tamilnadu, South India

    Science.gov (United States)

    Velraj, G.; Ramya, R.; Hemamalini, R.

    2012-11-01

    Scientific examination of archaeological pottery mainly aims to determine the style of production and the techniques involved in its manufacture. Technological characterization includes the evaluation of the original firing conditions. Maximum firing temperatures may be evaluated by firing clays of compositions similar to those used for the production of the ancient objects. In the present work, some of the ancient pottery samples were collected from recently excavated site at Adichanallur, Tirunelveli District, Tamilnadu, India to estimate the firing temperature of the pottery samples and atmosphere prevailed at the time of manufacturing those potteries by the ancient artisans. From the Fourier transform infrared spectra of the samples the lower limit of firing temperature have been determined. The upper limit of firing temperature was evaluated by porosimetry method. The scanning electron microscopic analysis is used to narrow down the range of firing temperature and the results are consistent with the results obtained from FT-IR spectroscopic study and porosimetry method.

  12. Molecular structure and vibrational analysis of Trifluoperazine by FT-IR, FT-Raman and UV-Vis spectroscopies combined with DFT calculations.

    Science.gov (United States)

    Rajesh, P; Gunasekaran, S; Gnanasambandan, T; Seshadri, S

    2015-02-25

    The complete vibrational assignment and analysis of the fundamental vibrational modes of Trifluoperazine (TFZ) was carried out using the experimental FT-IR, FT-Raman and UV-Vis data and quantum chemical studies. The observed vibrational data were compared with the wavenumbers derived theoretically for the optimized geometry of the compound from the DFT-B3LYP gradient calculations employing 6-31G (d,p) basis set. Thermodynamic properties like entropy, heat capacity and enthalpy have been calculated for the molecule. The HOMO-LUMO energy gap has been calculated. The intramolecular contacts have been interpreted using natural bond orbital (NBO) and natural localized molecular orbital (NLMO) analysis. Important non-linear properties such as first hyperpolarizability of TFZ have been computed using B3LYP quantum chemical calculation.

  13. Revealing the Nature and Distribution of Metal Carboxylates in Jackson Pollock's Alchemy (1947) by Micro-Attenuated Total Reflection FT-IR Spectroscopic Imaging.

    Science.gov (United States)

    Gabrieli, Francesca; Rosi, Francesca; Vichi, Alessandra; Cartechini, Laura; Pensabene Buemi, Luciano; Kazarian, Sergei G; Miliani, Costanza

    2017-01-17

    Protrusions, efflorescence, delamination, and opacity decreasing are severe degradation phenomena affecting oil paints with zinc oxide, one of the most common white pigments of the 20th century. Responsible for these dramatic alterations are the Zn carboxylates (also known as Zn soaps) originated by the interaction of the pigment and the fatty acids resulting from the hydrolysis of glycerides in the oil binding medium. Despite their widespread occurrence in paintings and the growing interest of the scientific community, the process of formation and evolution of Zn soaps is not yet fully understood. In this study micro-attenuated total reflection (ATR)-FT-IR spectroscopic imaging was required for the investigation at the microscale level of the nature and distribution of Zn soaps in the painting Alchemy by J. Pollock (1947, Peggy Guggenheim Collection, Venice) and for comparison with artificially aged model samples. For both actual samples and models, the role of AlSt(OH)2, a jellifying agent commonly added in 20th century paint tube formulations, proved decisive for the formation of zinc stearate-like (ZnSt2) soaps. It was observed that ZnSt2-like soaps first form around the added AlSt(OH)2 particles and then eventually grow within the whole painting stratigraphy as irregularly shaped particles. In some of the Alchemy samples, and diversely from the models, a peculiar distribution of ZnSt2 aggregates arranged as rounded and larger particles was also documented. Notably, in one of these samples, larger agglomerates of ZnSt2 expanding toward the support of the painting were observed and interpreted as the early stage of the formation of internal protrusions. Micro-ATR-FT-IR spectroscopic imaging, thanks to a very high chemical specificity combined with high spatial resolution, was proved to give valuable information for assessing the conservation state of irreplaceable 20th century oil paintings, revealing the chemical distribution of Zn soaps within the paint

  14. Identification of authentic and adulterated Aquilariae Lignum Resinatum by Fourier transform infrared (FT-IR) spectroscopy and two-dimensional correlation analysis

    Science.gov (United States)

    Qu, Lei; Chen, Jian-bo; Zhou, Qun; Zhang, Gui-jun; Sun, Su-qin; Guo, Yi-zhen

    2016-11-01

    As a kind of expensive perfume and valuable herb, the commercial Aquilariae Lignum Resinatum (ALR) is often adulterated for economic motivations. In this research, Fourier transform infrared (FT-IR) spectroscopy and two-dimensional (2D) correlation analysis are employed to establish a simple and quick identification method for the authentic and adulterated ALR. In the conventional infrared spectra, the standard ALR has a strong peak at 1658 cm-1 referring to the conjugated carbonyl of resin, while this peak is absent in the adulterated samples. The position, intensity, and shape of the auto-peaks and cross-peaks of the authentic and adulterated ALR are much different in the synchronous 2D correlation spectra with thermal perturbation. In the range of 1700-1500 cm-1, the standard ALR has four obvious auto-peaks, while the strongest one is at 1659 cm-1. The adulterated sample w-1 has three obvious auto-peaks and the strongest one is at 1647 cm-1. The adulterated sample w-2 has three obvious auto-peaks and the strongest one is at 1519 cm-1. The adulterated sample w-3 has four obvious auto-peaks and the strongest one is at 1690 cm-1. The above auto-peaks confirm that the standard ALR contains a certain content of resin compounds, while the three counterfeits contain little or different resins. The results show the potential of FT-IR spectroscopy and 2D correlation analysis in the simple and quick identification of authentic and adulterated ALR.

  15. Correcting the effect of refraction and dispersion of light in FT-IR spectroscopic imaging in transmission through thick infrared windows.

    Science.gov (United States)

    Chan, K L Andrew; Kazarian, Sergei G

    2013-01-15

    Transmission mode is one of the most common sampling methods for FT-IR spectroscopic imaging because the spectra obtained generally have a reasonable signal-to-noise ratio. However, dispersion and refraction of infrared light occurs when samples are sandwiched between infrared windows or placed underneath a layer of liquid. Dispersion and refraction cause infrared light to focus with different focal lengths depending on the wavelength (wavenumber) of the light. As a result, images obtained are in focus only at a particular wavenumber while they are defocused at other wavenumber values. In this work, a solution to correct this spread of focus by means of adding a lens on top of the infrared transparent window, such that a pseudo hemisphere is formed, has been investigated. Through this lens (or pseudo hemisphere), refraction of light is removed and the light across the spectral range has the same focal depth. Furthermore, the lens acts as a solid immersion objective and an increase of both magnification and spatial resolution (by 1.4 times) is demonstrated. The spatial resolution was investigated using an USAF resolution target, showing that the Rayleigh criterion can be achieved, as well as a sample with a sharp polymer interface to indicate the spatial resolution that can be expected in real samples. The reported approach was used to obtain chemical images of cross sections of cancer tissue and hair samples sandwiched between infrared windows showing the versatility and applicability of the method. In addition to the improved spatial resolution, the results reported herein also demonstrate that the lens can reduce the effect of scattering near the edges of tissue samples. The advantages of the presented approach, obtaining FT-IR spectroscopic images in transmission mode with the same focus across all wavenumber values and simultaneous improvement in spatial resolution, will have wide implications ranging from studies of live cells to sorption of drugs into tissues.

  16. Nutritional, phytochemical and antioxidant evaluation and FT-IR analysis of freeze dried extracts of Ecballium elaterium fruit juice from three localities

    Directory of Open Access Journals (Sweden)

    Samir FELHI

    2016-01-01

    Full Text Available Abstract This study was designed to investigate chemical composition, the total phenolic content, flavonoid content, antioxidant activity and to analyze through FT-IR spectroscopy method the freeze-dried extract of Ecballium elaterium fruit from three different localities. The highest level of phenolic and flavonoid contents was recorded for the fruit juice from the Cap-Bon region, with 106.4 ± 0.4 mg GAE/g and 6.5 ± 0.2 mg QE/g, respectively. Antioxidant activity varied in dose-dependent manner with IC50 values for DPPH scavenging of the freeze-dried fruit juice extracts from Cap-Bon, Kef and Sidi Bouzid were 38.6 ± 0.2, 50.1 ± 0.7, and 50.7 ± 0.2 µg/mL, respectively. The results from the FRAP test showed that the freeze-dried extracts of Cap-Bon exhibited potent activity, followed by those from Kef and Sidi Bouzid. Similar trend were revealed for ABTS•+ test, with the fruit juice extract from Cap-Bon (IC50 = 0.6 ± 0.0 mg/mL. Furthermore, a good positive correlation was observed between the total phenols and three assays, especially DPPH. The freeze-dried extracts of fruit juice from Cap-Bon showed strong ability to act as antioxidants and can be considered as promising natural source of bioactive compounds. FT-IR analysis of each freeze-dried extract confirmed its richness on polyphenols and biological active functional groups.

  17. Automated Fast Screening Method for Cocaine Identification in Seized Drug Samples Using a Portable Fourier Transform Infrared (FT-IR) Instrument.

    Science.gov (United States)

    Mainali, Dipak; Seelenbinder, John

    2016-05-01

    Quick and presumptive identification of seized drug samples without destroying evidence is necessary for law enforcement officials to control the trafficking and abuse of drugs. This work reports an automated screening method to detect the presence of cocaine in seized samples using portable Fourier transform infrared (FT-IR) spectrometers. The method is based on the identification of well-defined characteristic vibrational frequencies related to the functional group of the cocaine molecule and is fully automated through the use of an expert system. Traditionally, analysts look for key functional group bands in the infrared spectra and characterization of the molecules present is dependent on user interpretation. This implies the need for user expertise, especially in samples that likely are mixtures. As such, this approach is biased and also not suitable for non-experts. The method proposed in this work uses the well-established "center of gravity" peak picking mathematical algorithm and combines it with the conditional reporting feature in MicroLab software to provide an automated method that can be successfully employed by users with varied experience levels. The method reports the confidence level of cocaine present only when a certain number of cocaine related peaks are identified by the automated method. Unlike library search and chemometric methods that are dependent on the library database or the training set samples used to build the calibration model, the proposed method is relatively independent of adulterants and diluents present in the seized mixture. This automated method in combination with a portable FT-IR spectrometer provides law enforcement officials, criminal investigators, or forensic experts a quick field-based prescreening capability for the presence of cocaine in seized drug samples.

  18. Molecular structure, spectroscopic characterization (FT-IR, FT-Raman, UV and NMR), HOMO and LUMO analysis of 3-ethynylthiophene with DFT quantum chemical calculations

    Science.gov (United States)

    Karabacak, Mehmet; Bilgili, Sibel; Mavis, Tugba; Eskici, Mustafa; Atac, Ahmet

    2013-11-01

    In this work, FT-IR, FT-Raman, UV and NMR spectra of 3-ethynylthiophene (3-ETP, C6H4S) were carried out by using density functional theory DFT/B3LYP method with the 6-311++G(d,p), 6-311+G(d,p), 6-311G(d,p), 6-31++G(d,p), 6-31+G(d,p), 6-31G(d,p) basis sets. FT-IR and FT-Raman spectra were recorded in the regions of 3500-400 cm-1 and 3500-50 cm-1, respectively. The geometrical parameters, energies and wavenumbers were obtained and the complete assignments of fundamental vibrations were performed on the basis of the total energy distribution (TED) of the vibrational modes, calculated with scaled quantum mechanics (SQM) method and PQS program. The 1H, 13C and HMQC (1H-13C correlation) NMR spectra in chloroform (CDCl3) were recorded and calculated. The UV spectrum of investigated compound were recorded in the region of 200-400 nm in ethanol solution. The electronic properties, such as excitation energies, absorption wavelengths, HOMO and LUMO energies were performed by DFT/B3LYP approach and the results were compared with experimental observations. The thermodynamic properties such zero-point vibrational energy, thermal energy, specific heat capacity, rotational constants, entropy, and dipole moment of the studied compound were calculated. As a result, the calculated results were compared with the observed data and found to be in good agreement.

  19. NMR, FT-IR, Raman and UV-Vis spectroscopic investigation and DFT study of 6-Bromo-3-Pyridinyl Boronic Acid

    Science.gov (United States)

    Dikmen, Gökhan; Alver, Özgür

    2015-11-01

    Possible stable conformers and geometrical molecular structures of 6-Bromo-3-Pyridinyl Boronic acid (6B3PBA; C5H5BBrNO2) were studied experimentally and theoretically using FT-IR and Raman spectroscopic methods. FT-IR and Raman spectra were recorded in the region of 4000-400 cm-1 and 3700-400 cm-1, respectively. The structural properties were investigated further, using 1H, 13C, 1H coupled 13C, HETCOR, COSY and APT NMR techniques. The optimized geometric structures were searched by Becke-3-Lee-Yang-Parr (B3LYP) hybrid density functional theory method with 6-311++G(d, p) basis set. Vibrational wavenumbers of 6B3PBA were calculated whereby B3LYP density functional methods including 6-311++G(d, p), 6-311G(d, p), 6-311G(d), 6-31G(d, p) and 6-31G(d) basis sets. The comparison of the experimentally and theoretically obtained results using mean absolute error and experimental versus calculated correlation coefficients for the vibrational wavenumbers indicates that B3LYP method with 6-311++G(d, p) gives more satisfactory results for predicting vibrational wavenumbers when compared to the 6-311G(d, p), 6-311G(d), 6-31G(d, p) and 6-31G(d) basis sets. However, this method and none of the mentioned methods here seem suitable for the calculations of OH stretching modes, most likely because increasing unharmonicity in the high wave number region and possible intra and inter molecular interactions at OH edges lead some deviations between experimental and theoretical results. Moreover, reliable vibrational assignments were made on the basis of total energy distribution (TED) calculated using scaled quantum mechanical (SQM) method.

  20. Experimental (FT-IR, FT-Raman, UV-Vis, 1H and 13C NMR) and computational (density functional theory) studies on 3-bromophenylboronic acid

    Science.gov (United States)

    Karabacak, M.; Kose, E.; Atac, A.; Sas, E. B.; Asiri, A. M.; Kurt, M.

    2014-11-01

    Structurally, boronic acids are trivalent boron-containing organic compounds that possess one alkyl substituent (i.e., C-Br bond) and two hydroxyl groups to fill the remaining valences on the boron atom. We studied 3-bromophenylboronic acid (3BrPBA); a derivative of boronic acid. This study includes the experimental (FT-IR, FT-Raman, 1H and 13C NMR, UV-Vis) techniques and theoretical (DFT-density functional theory) calculations. The experimental data are recorded, FT-IR (4000-400 cm-1) and FT-Raman spectra (3500-10 cm-1) in the solid phase. 1H and 13C NMR spectra are recorded in DMSO solution. UV-Vis spectrum is recorded in the range of 200-400 nm for each solution (in ethanol and water). The theoretical calculations are computed DFT/B3LYP/6-311++G(d,p) basis set. The optimum geometry is also obtained from inside for possible four conformers using according to position of hydrogen atoms after the scan coordinate of these structures. The fundamental vibrations are assigned on the basis of the total energy distribution (TED) of the vibrational modes, calculated with scaled quantum mechanics (SQM) method and parallel quantum solutions (PQS) program. 1H and 13C NMR chemical shifts are racked on by using the gauge-invariant atomic orbital (GIAO) method. The time-dependent density functional theory (TD-DFT) is used to find HOMO and LUMO energies, excitation energies, oscillator strengths. The density of state of the studied molecule is investigated as total and partial density of state (TDOS and PDOS) and overlap population density of state (OPDOS or COOP) diagrams have been presented. Besides, frontier molecular orbitals (FMOs), molecular electrostatic potential surface (MEPs) and thermodynamic properties are performed. At the end of this work, the results are ensured beneficial for the literature contribution.

  1. Estudo de coprólito da bacia sedimentar do Araripe por meios de espectroscopia FT-IR e difração de Raios-X Study of coprolites from the Araripe sedimentary basin through FT-IR spectroscopy and x-ray diffraction

    Directory of Open Access Journals (Sweden)

    Ricardo Jorge Cruz Lima

    2007-01-01

    Full Text Available Coprolites are fossilized faeces that constitute an important source of palaeobiological informations. This paper describes the characterization of some coprolite materials originated from the Romualdo Member of the Santana Formation (Araripe Basin, south of Ceará State in Brazil by means of two techniques: X-ray powder diffraction and Fourier transform infrared spectroscopy (FT-IR. This characterization allowed us to determine the main composition of the coprolites, of the nodulus (where the coprolites were extracted and of the sediment (where the nodulus was found suggesting that the material was produced by a carnivorous fish of the Lower Cretaceous.

  2. Quantitative analysis of surface amine groups on plasma-polymerized ethylenediamine films using UV-visible spectroscopy compared to chemical derivatization with FT-IR spectroscopy, XPS and TOF-SIMS

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jinmo [Department of Physics, Brain Korea 21 Physics Research Division and Institute of Basic Science, Sungkyunkwan University (SKKU), Suwon 440-746 (Korea, Republic of); Division of Advanced Technology, Korea Research Institute of Standards and Science (KRISS), Daejeon 305-600 (Korea, Republic of); Jung, Donggeun [Department of Physics, Brain Korea 21 Physics Research Division and Institute of Basic Science, Sungkyunkwan University (SKKU), Suwon 440-746 (Korea, Republic of); Park, Yongsup [Division of Advanced Technology, Korea Research Institute of Standards and Science (KRISS), Daejeon 305-600 (Korea, Republic of); Kim, Yongki [Department of Physics, Brain Korea 21 Physics Research Division and Institute of Basic Science, Sungkyunkwan University (SKKU), Suwon 440-746 (Korea, Republic of); Division of Advanced Technology, Korea Research Institute of Standards and Science (KRISS), Daejeon 305-600 (Korea, Republic of); Moon, Dae Won [Division of Advanced Technology, Korea Research Institute of Standards and Science (KRISS), Daejeon 305-600 (Korea, Republic of); Lee, Tae Geol [Division of Advanced Technology, Korea Research Institute of Standards and Science (KRISS), Daejeon 305-600 (Korea, Republic of)]. E-mail: tglee@kriss.re.kr

    2007-02-28

    A quantitative analysis of the surface density of amine groups on a plasma-polymerized ethylenediamine thin film deposited on a platinum surface using inductively coupled plasma chemical vapor deposition method is described. UV-visible spectroscopy together with a chemical derivatization technique using Fourier transform infrared (FT-IR) spectroscopy was used to obtain the quantitative information. Chemical tags of pentafluorobenzaldehyde were hybridized with the surface amine groups and were easily detected due to the characteristic absorption bands of C-F stretching, aromatic ring and C=N stretching vibrations in the reflection-absorption FT-IR spectra. The surface amine density was reproducibly controlled as a function of deposition plasma power and quantified using UV-visible spectroscopy. A good linear correlation was observed between the FT-IR intensities of the characteristic absorption bands and the surface amine densities, suggesting the possibility of using this chemical derivatization technique to quantify the surface densities of specific functional groups on an organic surface. Chemical derivatization was also used with X-ray photoelectron spectroscopy on the same samples, and the results were compared with those obtained from FT-IR and time-of-flight secondary ion mass spectrometry. Although each analysis technique has different probing depths from the surface, the three different data sets obtained from the chemical tags correlated well with each other since each analysis technique measured the chemical tags on the sample surface.

  3. Pyrolysis Mechanism of Sawdust Based on TG-FT IR Analysis%基于TG-FT IR分析的木屑热解机理

    Institute of Scientific and Technical Information of China (English)

    顾晓利; 马旭; 李丽鲜; 程康华; 李忠正; 肖睿

    2013-01-01

    Pyrolysis of certain sawdust was studied by using thermogravimetric analyzer coupled with Fourier transform infrared spectroscopy (TG-FT IR). The dynamics parameters of sawdust pyrolysis were calculated by the methods of Kissinger and Ozawa, respectively. Large-scale experiment of sawdust pyrolysis was conducted in the fixed bed device. With different heating rates and at the final temperature of 950℃ , a total loss mass fraction of 77% -83% was observed. The temperature trend of evolving gaseous products, such as CH4 , CO and CO2 was investigated. At a temperature above 200°C , the pyrolysis of sawdust was clearly accelerated and the maximum temperature corresponding to the pyrolysis shifted to high temperature with the increase of heating rates. The activation energy of sawdust was of 130. 14 and 133. 21 kJ/mol, respectively, and the frequency factor(lnA) of 26. 28 and 26. 47 min-1 calculated by Kissinger and Ozawa methods. The optimal sawdust pyrolysis temperature was above 700℃ with CO, CO2 , CH4 and H2 as the main pyrolysis products. With the increase of temperature, the volume fraction of CO decreased rapidly while the volume fraction of H2 increased evidently, and the volume fractions of CO2 and CH4 maintained relatively unchanged during the pyrolysis. The results obtained by the experiment in  fixed bed device were consistent with the results of TG-FT IR experiment.%采用热重-红外联用(TG-FT IR)方法考察了木屑的热解规律,选择Kissinger和Ozawa 2种算法对木屑热解动力学参数进行估算,并采用固定床实验装置考察了木屑热解反应温度对产物分布的影响.结果表明,在不同升温速率及热解终温为950℃的热解条件下,木屑底物的失重率维持在77%~83%,且热解产物以气相产物为主,包括CO2、CH4、CO等;当温度高于200℃时,底物出现明显的热解过程,最高失重率下对应的温度随着升温速率的增加而升高.Kissinger和Ozawa 2种算法得出木屑

  4. Cysteine, thiourea and thiocyanate interactions with clays: FT-IR, Mössbauer and EPR spectroscopy and X-ray diffractometry studies.

    Science.gov (United States)

    de Santana, Henrique; Paesano, Andrea; da Costa, Antonio C S; di Mauro, Eduardo; de Souza, Ivan G; Ivashita, Flávio F; de Souza, Cláudio M D; Zaia, Cássia T B V; Zaia, Dimas A M

    2010-04-01

    The present study examined the adsorption of cysteine, thiourea and thiocyanate on bentonite and montmorillonite at two different pHs (3.00, 8.00). The conditions used here are closer to those of prebiotic earth. As shown by FT-IR, Mössbauer and EPR spectroscopy and X-ray diffractometry, the most important finding of this work is that cysteine and thiourea penetrate into the interlayer of the clays and reduce Fe(3+) to Fe(2+), and as consequence, cystine and c,c'-dithiodiformamidinium ion are formed. This mechanism resembles that which occurs with aconitase. This is a very important result for prebiotic chemistry; we should think about clays not just sink of molecules, but as primitive vessels of production of biomolecules. At pH 8.00, an increasing expansion was observed in the following order for both minerals: thiourea > thiocyanate > cysteine. At pH 3.00, the same order was not observed and thiourea had an opposite behavior, being the compound producing the lowest expansion. Mössbauer spectroscopy showed that at pH 8.00, the proportion of Fe(2+) ions in bentonite increased, doubling for thiourea, or more than doubling for cysteine, in both clays. However, at pH 3.00, cysteine and thiourea did not change significantly the relative amount of Fe(2+) and Fe(3+) ions, when compared to clays without adsorption. For thiocyanate, the amount of Fe(2+) produced was independent of the pH or clay used, probably because the interlayers of clays are very acidic and HSCN formed does not reduce Fe(3+) to Fe(2+). For the interaction of thiocyanate with the clays, it was not possible to identify any potential compound formed. For the samples of bentonite and montmorillonite at pH 8.00 with cysteine, EPR spectroscopy showed that intensity of the lines due to Fe(3+) decreased because the reaction of Fe(3+)/cysteine. Intensity of EPR lines did not change when the samples of bentonite at pH 3.00 with and without cysteine were compared. These results are in accordance with those

  5. Physicochemical characterization by AFM, FT-IR and DSC and biological assays of a promising antileishmania delivery system loaded with a natural Brazilian product.

    Science.gov (United States)

    Marquele-Oliveira, Franciane; Torres, Elina Cassia; Barud, Hernane da Silva; Zoccal, Karina Furlani; Faccioli, Lúcia Helena; Hori, Juliana I; Berretta, Andresa Aparecida

    2016-05-10

    The control and treatment of Leishmaniasis, a neglected and infectious disease affecting approximately 12 million people worldwide, are challenging. Leishmania parasites multiply intracellularly within macrophages located in deep skin and in visceral tissues, and the currently employed treatments for this disease are subject to significant drawbacks, such as resistance and toxicity. Thus, the search for new Leishmaniasis treatments is compulsory, and Ocotea duckei Vattimo, a plant-derived product from the biodiverse Brazilian flora, may be a promising new treatment for this disease. In this regard, the aim of this work was to develop and characterize a delivery system based on solid lipid nanoparticles (SLN) that contain the liposoluble lignan fraction (LF) of Ocotea duckei Vattimo, which targets the Leishmania phagolysosome of infected macrophages. LF-loaded SLNs were obtained via the hot microemulsion method, and their physical and chemical properties were comprehensively assessed using PCS, AFM, SEM, FT-IR, DSC, HPLC, kinetic drug release studies, and biological assays. The size of the developed delivery system was 218.85±14.2 nm, its zeta potential was -30 mV and its entrapment efficiency (EE%) was high (the EEs% of YAN [yangambin] and EPI-YAN [epi-yangambin] markers were 94.21±0.40% and 94.20±0.00%, respectively). Microscopy, FT-IR and DSC assays confirmed that the delivery system was nanosized and indicated a core-shell encapsulation model, which corroborated the measured kinetics of drug release. The total in vitro release rates of YAN and EPI-YAN in buffer (with sink conditions attained) were 29.6±8.3% and 34.3±8.9%, respectively, via diffusion through the cellulose acetate membrane of the SLN over a period of 4 h. After 24 h, the release rates of both markers reached approximately 45%, suggesting a sustained pattern of release. Mathematical modeling indicated that both markers, YAN and EPI-YAN, followed matrix diffusion-based release kinetics (Higuchi

  6. 14NH_3 Line Positions and Intensities in the Far-Infrared Comparison of Ft-Ir Measurements to Empirical Hamiltonian Model Predictions

    Science.gov (United States)

    Sung, Keeyoon; Yu, Shanshan; Pearson, John; Pirali, Olivier; Kwabia Tchana, F.; Manceron, Laurent

    2016-06-01

    We have analyzed multiple spectra of high purity (99.5%) normal ammonia sample recorded at room temperatures using the FT-IR and AILES beamline at Synchrotron SOLEIL, France. More than 2830 line positions and intensities are measured for the inversion-rotation and rovibrational transitions in the 50 - 660 wn region. Quantum assignments were made for 2047 transitions from eight bands including four inversion-rotation bands (gs(a-s), νb{2}(a-s), 2νb{2}(a-s), and νb{4}(a-s)) and four ro-vibrational bands (νb{2} - gs, 2νb{2} - gs, νb{4} - νb{2}, and 2νb{2} -νb{4}), as well as covering more than 300 lines of ΔK = 3 forbidden transitions. Out of the eight bands, we note that 2νb{2} - νb{4} has not been listed in the HITRAN 2012 database. The measured line positions for the assigned transitions are in an excellent agreement (typically better than 0.001 wn) with the predictions from the empirical Hamiltonian model [S. Yu, J.C. Pearson, B.J. Drouin, et al.(2010)] in a wide range of J and K for all the eight bands. The comparison with the HITRAN 2012 database is also satisfactory, although systematic offsets are seen for transitions with high J and K and those from weak bands. However, differences of 20% or so are seen in line intensities for allowed transitions between the measurements and the model predictions, depending on the bands. We have also noticed that most of the intensity outliers in the Hamiltonian model predictions belong to transitions from gs(a-s) band. We present the final results of the FT-IR measurements of line positions and intensities, and their comparisons to the model predictions and the HITRAN 2012 database. Research described in this paper was performed at the Jet Propulsion Laboratory and California Institute of Technology, under contracts and cooperative agreements with the National Aeronautics and Space Administration.

  7. Investigation of the Changes in Surface Area and FT-IR Spectra of Activated Carbons Obtained from Hazelnut Shells by Physicochemical Treatment Methods

    Directory of Open Access Journals (Sweden)

    Aziz Şencan

    2015-01-01

    Full Text Available In this study, raw hazelnut shells were used to obtain charcoal by pyrolysis at 250°C. The obtained material was subjected to physical, chemical, and physicochemical treatment methods to obtain activated carbons (ACs. Effect of the treatment procedures was determined by measuring the surface area of the produced ACs. In addition, changes in the functional groups of the obtained ACs during these treatments were determined with the Fourier transform infrared spectroscopy (FT-IR. To determine the most effective chemical agent, the charcoal samples were examined for Pb(II adsorption from aqueous solutions under different pH conditions of 4 to 6. According to the results, the most effective chemical agent was determined as Ca(OCl2. Effect of microwave and ultrasound treatments was also examined during Pb(II adsorption by the chemically treated AC. The results showed that chemical treatment with Ca(OCl2, microwave treatment for 5 minutes, ultrasound treatment for 20 minutes, and pyrolysis at 700°C together were the most suitable combination enhancing the surface area of the adsorbent. This combination increased the surface area and the adsorption capacity of the adsorbent by 202 and 4.76 times, respectively, when compared to those of the raw hazelnut shell.

  8. Time-resolved spectral characterization of ring cavity surface emitting and ridge-type distributed feedback quantum cascade lasers by step-scan FT-IR spectroscopy.

    Science.gov (United States)

    Brandstetter, Markus; Genner, Andreas; Schwarzer, Clemens; Mujagic, Elvis; Strasser, Gottfried; Lendl, Bernhard

    2014-02-10

    We present the time-resolved comparison of pulsed 2nd order ring cavity surface emitting (RCSE) quantum cascade lasers (QCLs) and pulsed 1st order ridge-type distributed feedback (DFB) QCLs using a step-scan Fourier transform infrared (FT-IR) spectrometer. Laser devices were part of QCL arrays and fabricated from the same laser material. Required grating periods were adjusted to account for the grating order. The step-scan technique provided a spectral resolution of 0.1 cm(-1) and a time resolution of 2 ns. As a result, it was possible to gain information about the tuning behavior and potential mode-hops of the investigated lasers. Different cavity-lengths were compared, including 0.9 mm and 3.2 mm long ridge-type and 0.97 mm (circumference) ring-type cavities. RCSE QCLs were found to have improved emission properties in terms of line-stability, tuning rate and maximum emission time compared to ridge-type lasers.

  9. Copper Enhanced Monooxygenase Activity and FT-IR Spectroscopic Characterisation of Biotransformation Products in Trichloroethylene Degrading Bacterium: Stenotrophomonas maltophilia PM102

    Directory of Open Access Journals (Sweden)

    Piyali Mukherjee

    2013-01-01

    Full Text Available Stenotrophomonas maltophilia PM102 (NCBI GenBank Acc. no. JQ797560 is capable of growth on trichloroethylene as the sole carbon source. In this paper, we report the purification and characterisation of oxygenase present in the PM102 isolate. Enzyme activity was found to be induced 10.3-fold in presence of 0.7 mM copper with a further increment to 14.96-fold in presence of 0.05 mM NADH. Optimum temperature for oxygenase activity was recorded at 36∘C. The reported enzyme was found to have enhanced activity at pH 5 and pH 8, indicating presence of two isoforms. Maximum activity was seen on incubation with benzene compared to other substrates like TCE, chloroform, toluene, hexane, and petroleum benzene. Km and Vmax for benzene were 3.8 mM and 340 U/mg/min and those for TCE were 2.1 mM and 170 U/mg/min. The crude enzyme was partially purified by ammonium sulphate precipitation followed by dialysis. Zymogram analysis revealed two isoforms in the 70% purified enzyme fraction. The activity stain was more prominent when the native gel was incubated in benzene as substrate in comparison to TCE. Crude enzyme and purified enzyme fractions were assayed for TCE degradation by the Fujiwara test. TCE biotransformation products were analysed by FT-IR spectroscopy.

  10. Acid-base properties, FT-IR, FT-Raman spectroscopy and computational study of 1-(pyrid-4-yl)piperazine.

    Science.gov (United States)

    Mary, Y Sheena; Panicker, C Yohannan; Varghese, Hema Tresa; Van Alsenoy, Christian; Procházková, Markéta; Sevčík, Richard; Pazdera, Pavel

    2014-01-01

    We report the vibrational spectral analysis was carried out using FT-IR and FT-Raman spectroscopy for 1-(pyrid-4-yl)piperazine (PyPi). Single crystals of PyPi suitable for X-ray structural analysis were obtained. The acid-base properties are also reported. PyPi supported on a weak acid cation-exchanger in the single protonated form and this system can be used efficiently as the solid supported analogue of 4-N,N-dimethyl-aminopyridine. The complete vibrational assignments of wavenumbers were made on the basis of potential energy distribution. The HOMO and LUMO analysis is used to determine the charge transfer within the molecule and with the molecular electrostatic potential map was applied for the reactivity assessment of PyPi molecule toward proton, electrophiles and nucleopholes as well. The stability of the molecule arising from hyper-conjugative interaction and charge delocalization has been analyzed using NBO analysis. The calculated first hyperpolarizability of PyPi is 17.46 times that of urea.

  11. Curcumin-β-cyclodextrin inclusion complex: stability, solubility, characterisation by FT-IR, FT-Raman, X-ray diffraction and photoacoustic spectroscopy, and food application.

    Science.gov (United States)

    Mangolim, Camila Sampaio; Moriwaki, Cristiane; Nogueira, Ana Claudia; Sato, Francielle; Baesso, Mauro Luciano; Neto, Antônio Medina; Matioli, Graciette

    2014-06-15

    Curcumin was complexed with β-CD using co-precipitation, freeze-drying and solvent evaporation methods. Co-precipitation enabled complex formation, as indicated by the FT-IR and FT-Raman techniques via the shifts in the peaks that were assigned to the aromatic rings of curcumin. In addition, photoacoustic spectroscopy and X-ray diffraction, with the disappearance of the band related to aromatic rings, by Gaussian fitting, and modifications in the spectral lines, respectively, also suggested complex formation. The possible complexation had an efficiency of 74% and increased the solubility of the pure colourant 31-fold. Curcumin-β-CD complex exhibited a sunlight stability 18% higher than the pure colourant. This material was stable to pH variations and storage at -15 and 4°C. With an isothermal heating at 100 and 150°C for 2h, the material exhibited a colour retention of approximately 99%. The application of curcumin-β-CD complex in vanilla ice creams intensified the colour of the products and produced a great sensorial acceptance.

  12. FT-IR, FT-Raman, UV/Vis spectra and fluorescence imaging studies on 2-(bromoacetyl)benzo(b)furan by ab initio DFT calculations.

    Science.gov (United States)

    Veeraiah, A

    2015-08-05

    The vibrational and electronic properties of 2-(bromoacetyl)benzo(b)furan have been studied in the ground state using experimental techniques (FT-IR, FT-Raman and UV) and density functional theory (DFT) employing B3LYP exchange correlation with the 6-31G(d,p) basis set. The theoretically calculated optimized parameters, vibrational frequencies etc., were compared with the experimental values, which yield good agreement between the observed and calculated values. The complete assignments of fundamental modes were performed on the basis of the potential energy distribution (PED). UV-visible spectrum of the compound was recorded in the region 300-600 nm and compared with the theoretical spectrum obtained from SAC-CI calculations. A good agreement is observed between the experimental and theoretical spectra. Fluorescence microscopic imaging studies proved that the compound can be used as one of the potential light sources in the yellow region with suitable excitation. Further, the predicted electronic transitions between the MOs 47→64, 52→62, 56→65, 56→72, 56→77 of the compound show a strong line at 569.8 nm. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Proteolytically-induced changes of secondary structural protein conformation of bovine serum albumin monitored by Fourier transform infrared (FT-IR) and UV-circular dichroism spectroscopy

    Science.gov (United States)

    Güler, Günnur; Vorob'ev, Mikhail M.; Vogel, Vitali; Mäntele, Werner

    2016-05-01

    Enzymatically-induced degradation of bovine serum albumin (BSA) by serine proteases (trypsin and α-chymotrypsin) in various concentrations was monitored by means of Fourier transform infrared (FT-IR) and ultraviolet circular dichroism (UV-CD) spectroscopy. In this study, the applicability of both spectroscopies to monitor the proteolysis process in real time has been proven, by tracking the spectral changes together with secondary structure analysis of BSA as proteolysis proceeds. On the basis of the FTIR spectra and the changes in the amide I band region, we suggest the progression of proteolysis process via conversion of α-helices (1654 cm- 1) into unordered structures and an increase in the concentration of free carboxylates (absorption of 1593 and 1402 cm- 1). For the first time, the correlation between the degree of hydrolysis and the concentration of carboxylic groups measured by FTIR spectroscopy was revealed as well. The far UV-CD spectra together with their secondary structure analysis suggest that the α-helical content decreases concomitant with an increase in the unordered structure. Both spectroscopic techniques also demonstrate that there are similar but less spectral changes of BSA for the trypsin attack than for α-chymotrypsin although the substrate/enzyme ratio is taken the same.

  14. A unique manganese (II) complex of 4-methoxy-pyridine-2-carboxylate: Synthesis, crystal structure, FT-IR and UV-Vis spectra and DFT calculations

    Science.gov (United States)

    Tamer, Ömer

    2017-09-01

    The first metal complex of 4-Methoxy-pyridine-2-carboxylic acid, [Mn(4-mpic)2(H2O)2], has been synthesized, and its crystal structure has been determined by X-Ray diffraction method. The FT-IR spectrum for [Mn(4-mpic)2(H2O)2] complex has been presented in this paper, as compared with that of single 4-mpic ligand. The electronic absorption spectrum recorded in DMSO solvent revealed that the ligand metal charge transfer (LMCT) interactions occur in Mn(II) complex. In order to support experimental results, density functional theory (DFT) calculations have been also carried out with the hybrid B3LYP functional. The coordination sphere of central Mn(II) ion has been evaluated by using the hyperconjugative interactions between the lone pair electrons of metal and donor atoms (N and O). The natural charge of Mn(II) ion demonstrated that the electronic transitions from metal ion to 4-mpic are higher than those in reverse direction. The carboxylate group has been determined as the most reactive side of Mn(II) complex in chemical reactions. A comparison among Mulliken, NBO and APT charges has been carried out for Mn(II) complex system. The first static hyperpolarizability parameter for Mn(II) complex has been also investigated by using B3LYP level.

  15. Preparation and characterizations of SnO2 nanopowder and spectroscopic (FT-IR, FT-Raman, UV-Visible and NMR) analysis using HF and DFT calculations.

    Science.gov (United States)

    Ayeshamariam, A; Ramalingam, S; Bououdina, M; Jayachandran, M

    2014-01-24

    In this work, pure and singe phase SnO2 Nano powder is successfully prepared by simple sol-gel combustion route. The photo luminescence and XRD measurements are made and compared the geometrical parameters with calculated values. The FT-IR and FT-Raman spectra are recorded and the fundamental frequencies are assigned. The optimized parameters and the frequencies are calculated using HF and DFT (LSDA, B3LYP and B3PW91) theory in bulk phase of SnO2 and are compared with its Nano phase. The vibrational frequency pattern in nano phase gets realigned and the frequencies are shifted up to higher region of spectra when compared with bulk phase. The NMR and UV-Visible spectra are simulated and analyzed. Transmittance studies showed that the HOMO-LUMO band gap (Kubo gap) is reduced from 3.47 eV to 3.04 eV while it is heated up to 800°C. The Photoluminescence spectra of SnO2 powder showed a peak shift towards lower energy side with the change of Kubo gap from 3.73 eV to 3.229 eV for as-prepared and heated up to 800°C. Crown Copyright © 2013. Published by Elsevier B.V. All rights reserved.

  16. Experimental and theoretical studies of (FT-IR, FT-Raman, UV-Visible and DFT) 4-(6-methoxynaphthalen-2-yl) butan-2-one.

    Science.gov (United States)

    Govindasamy, P; Gunasekaran, S

    2015-01-01

    In this work, the vibrational spectral analysis was carried out by using FT-Raman and FT-IR spectroscopy in the range 4000-50 cm(-1) and 4000-450 cm(-1) respectively for 4-(6-methoxynaphthalen-2-yl) butan-2-one (abbreviated as 4MNBO) molecule. Theoretical calculations were performed by density functional theory (DFT/B3LYP) method using 6-311G(d,p) and 6-311++G(d,p) basis sets. The difference between the observed and calculated wavenumber value of most of the fundamentals were very small. The complete vibrational assignments of wavenumbers were made on the basis of potential energy distribution (PED). The UV-Vis spectrum was recorded in the methanol solution. The energy, wavelength and oscillator's strength were calculated by Time Dependent Density Functional Theory (TD-DFT) and matched to the experimental findings. The intramolecular contacts have been interpreted using natural bond orbital (NBO) and natural localized molecular orbital (NLMO) analysis. Thermodynamic properties of 4MNBO at different temperature have been calculated. The molecular electrostatic potential surface (MESP) and Frontier molecular orbital's (FMO's) analysis were investigated using theoretical calculations. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Molecular vibrational investigation [FT-IR, FT-Raman, UV-Visible and NMR] on Bis(thiourea) Nickel chloride using HF and DFT calculations.

    Science.gov (United States)

    Anand, S; Sundararajan, R S; Ramachandraraja, C; Ramalingam, S; Durga, R

    2015-03-05

    In the present research work, the FT-IR, FT-Raman spectra of the Bis(thiourea) Nickel chloride (BTNC) were recorded and analyzed. The observed fundamental frequencies in finger print and functional group regions were assigned according to their uniqueness region. The computational calculations were carried out by HF and DFT (B3LYP and B3PW91) methods with 6-31++G(d,p) and 6-311++G(d,p) basis sets and the corresponding results were tabulated. The present organo-metallic compound was made up of covalent and coordination covalent bonds. The modified vibrational pattern of the complex molecule associated with ligand group was analyzed. Furthermore, the (13)C NMR and (1)H NMR spectral data were calculated by using the gauge independent atomic orbital (GIAO) method with B3LYP/6-311++G(d,p) basis set and their spectra were simulated and the chemical shifts linked to TMS were compared. A investigation on the electronic and optical properties; absorption wavelengths, excitation energy, dipole moment and frontier molecular orbital energies were carried out. The kubo gap of the present compound was calculated related to HOMO and LUMO energies which confirm the occurring of charge transformation between the base and ligand. Besides frontier molecular orbitals (FMO), molecular electrostatic potential (MEP) was performed. The NLO properties related to Polarizability and hyperpolarizability based on the finite-field approach were also discussed. Crown Copyright © 2014. Published by Elsevier B.V. All rights reserved.

  18. NMR, FT-IR, FT-Raman, UV spectroscopic, HOMO-LUMO and NBO analysis of cumene by quantum computational methods

    Science.gov (United States)

    Sivaranjani, T.; Xavier, S.; Periandy, S.

    2015-03-01

    This work presents the investigation of cumene using the FT-IR, FT-Raman, NMR and UV spectra obtained through various spectroscopic techniques. The theoretical vibrational frequencies and optimized geometric parameters have been calculated by using HF and density functional theory with the hybrid methods B3LYP, B3PW91 and 6-311+G(d,p)/6-311++G(d,p) basis sets. The theoretical vibrational frequencies have been scaled and compared with the corresponding experimental data. 1H and 13C NMR spectra were recorded and chemical shifts of the molecule were compared to TMS by using the Gauge-Independent Atomic Orbital (GIAO) method. A study on the electronic and optical properties, absorption wavelengths, excitation energy, dipole moment and frontier molecular orbital energies, and potential energy surface (PES) is performed using HF and DFT methods. The thermodynamic properties (heat capacity, entropy and enthalpy) at different temperatures are also calculated. NBO analysis is carried out to picture the charge transfer between the localized bonds and lone pairs. NLO properties related to polarizability and hyperpolarizability are also discussed.

  19. Tianeptine, olanzapine and fluoxetine show similar restoring effects on stress induced molecular changes in mice brain: An FT-IR study

    Science.gov (United States)

    Türker-Kaya, Sevgi; Mutlu, Oğuz; Çelikyurt, İpek K.; Akar, Furuzan; Ulak, Güner

    2016-05-01

    Chronic stress which can cause a variety of disorders and illness ranging from metabolic and cardiovascular to mental leads to alterations in content, structure and dynamics of biomolecules in brain. The determination of stress-induced changes along with the effects of antidepressant treatment on these parameters might bring about more effective therapeutic strategies. In the present study, we investigated unpredictable chronic mild stress (UCMS)-induced changes in biomolecules in mouse brain and the restoring effects of tianeptine (TIA), olanzapine (OLZ) and fluoxetine (FLX) on these variations, by Fourier transform infrared (FT-IR) spectroscopy. The results revealed that chronic stress causes different membrane packing and an increase in lipid peroxidation, membrane fluidity. A significant increment for lipid/protein, Cdbnd O/lipid, CH3/lipid, CH2/lipid, PO-2/lipid, COO-/lipid and RNA/protein ratios but a significant decrease for lipid/protein ratios were also obtained. Additionally, altered protein secondary structure components were estimated, such as increment in random coils and beta structures. The administration of TIA, OLZ and FLX drugs restored these stress-induced variations except for alterations in protein structure and RNA/protein ratio. This may suggest that these drugs have similar restoring effects on the consequences of stress activity in brain, in spite of the differences in their action mechanisms. All findings might have importance in understanding molecular mechanisms underlying chronic stress and contribute to studies aimed for drug development.

  20. Application of experimental design in examination of the dissolution rate of carbamazepine from formulations: Characterization of the optimal formulation by DSC, TGA, FT-IR and PXRD analysis

    Directory of Open Access Journals (Sweden)

    Krstić Marko

    2015-01-01

    Full Text Available Poor solubility is one of the key reasons for the poor bioavailability of these drugs. This paper displays a formulation of a solid surfactant system with carbamazepine, in order to increase its dissolution rate. Solid state surfactant systems are formed by application of fractal experimental design. Poloxamer 237 and Poloxamer 338 were used as surfactants and Brij® 35 was used as the co-surfactant. The ratios of the excipients and carbamazepine were varied and their effects on the dissolution rate of carbamazepine were examined. Moreover, the effects of the addition of natural (diatomite and a synthetic adsorbent carrier (Neusiline UFL2 on the dissolution rate of carbamazepine were also tested. The prepared surfactant systems were characterized and the influence of the excipients on possible changes of the polymorphous form of carbamazepine examined by application of analytical techniques (DSC, TGA, FT-IR, PXRD. It was determined that an appropriate selection of the excipient type and ratio could provide a significant increase in the carbamazepine dissolution rate. By application of analytical techniques, it was found that that the employed excipients induce a transition of carbamazepine into the amorphous form and that the selected sample was stable for three months, when kept under ambient conditions. [Projekat Ministarstva nauke Republike Srbije, br. TR34007

  1. Molecular structure, vibrational analysis (FT-IR, FT-Raman), NMR, UV, NBO and HOMO-LUMO analysis of N,N-Diphenyl Formamide based on DFT calculations.

    Science.gov (United States)

    Mathammal, R; Monisha, N R; Yasaswini, S; Krishnakumar, V

    2015-03-15

    In this work, the vibrational spectral analysis is carried out by using Raman and infrared spectroscopy in the range 4000-400 cm(-1) and 4000-50 cm(-1) respectively for N,N-Diphenyl Formamide (DPF) molecule. The optimized molecular structures, vibrational frequencies and corresponding vibrational assignments, nuclear magnetic resonance (NMR) and ultraviolet-visible (UV-VIS) spectra of the title molecule are evaluated using density functional theory (DFT) with standard B3LYP/6-31G(d,p) basis set. The harmonic vibrational frequencies are calculated and the scaled values have been compared with experimental FT-IR and FT-Raman spectra. The observed and calculated frequencies are found to be in good agreement. The stability of the molecule arising from hyper conjugative interactions and the charge delocalization has been analyzed using natural bond (NBO) analysis. The possible electronic transitions are determined by HOMO-LUMO orbital shapes and their energies. Thermodynamic properties (heat capacity, entropy and enthalpy) and the first hyperpolarizability of the title compound are calculated. The Mulliken charges and electric dipole moment of the molecule are computed using DFT calculations. The (1)H and (13)C nuclear magnetic resonance (NMR) chemical shift of the molecules are calculated by the gauge independent atomic orbital (GIAO) method and compared with experimental results. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. The spectroscopic properties of anticancer drug Apigenin investigated by using DFT calculations, FT-IR, FT-Raman and NMR analysis

    Science.gov (United States)

    Mariappan, G.; Sundaraganesan, N.; Manoharan, S.

    2012-09-01

    The FT-Raman and FT-Infrared spectra of solid Apigenin sample were measured in order to elucidate the spectroscopic properties of title molecule in the spectral range of 3500-50 cm-1 and 4000-400 cm-1, respectively. The recorded FT-IR and FT-Raman spectral measurements favor the calculated (by B3LYP/6-31G(d,p) method) structural parameters which are further supported by spectral simulation. Additional support is given by the collected 1H and 13C NMR spectra recorded with the sample dissolved in DMSO. The predicted chemical shifts at the B3LYP/6-31G(d) level obtained using the Gauge-Invariant Atomic Orbitals (GIAO) method with and without inclusion of solvent using the Polarizable Continuum Model (PCM). By using TD-DFT method, electronic absorption spectra of the title compound have been predicted and a good agreement with the TD-DFT method and the experimental one is determined. The UV-visible absorption spectra of the compound that dissolved in Ethanol, Methanol and DMSO were recorded in the range of 800-200 nm. The formation of hydrogen bond and the most possible interaction are explained using natural bond orbital (NBO) analysis. In addition, the molecular electrostatic potential (MEP), frontier molecular orbitals (FMO) analysis and atomic charges of the title compound were investigated using theoretical calculations. The results are discussed herein and compared with similar molecules whenever appropriate.

  3. Determinação por FT-IR de transmissão e reflexão (UATR de etileno e propileno em EPDM

    Directory of Open Access Journals (Sweden)

    Denis Damazio

    2014-12-01

    Full Text Available Foi desenvolvida uma metodologia para a determinação dos teores de etileno (ET e propileno (P em amostras de borracha (elastômero puro, crua e vulcanizada, à base do copolímero de etileno-propileno-dieno monômero (EPDM, por espectroscopia no infravermelho com transformada de Fourier (FT-IR de reflexão total atenuada universal (UATR e de transmissão, sendo as amostras analisadas tal como recebidas ou após pirólise, respectivamente. Embora ambas as técnicas tenham apresentado boa precisão, com a análise UATR sendo mais adequada para o elastômero puro, a realizada por transmissão/pirólise mostrou-se mais adequada à análise de todos os tipos de EPDM (elastômero puro, crua e vulcanizada, podendo ser usada para formulações similares.

  4. Quantum chemical calculation (electronic and topologic) and experimental (FT-IR, FT-Raman and UV) analysis of isonicotinic acid N-oxide

    Science.gov (United States)

    Karaca, Caglar; Atac, Ahmet; Karabacak, Mehmet

    2015-04-01

    In this work, the molecular conformation, vibrational and electronic analysis of isonicotinic acid N-oxide (iso-NANO) were presented in the ground state using experimental techniques (FT-IR, FT-Raman and UV) and density functional theory (DFT) employing B3LYP exchange correlation with the 6-311++G(d,p) basis set. The geometry optimization and energies associated possible two conformers (Rot-I and Rot-II) were computed. The vibrational spectra were calculated and fundamental vibrations were assigned on the basis of the total energy distribution (TED) of the vibrational modes, calculated with scaled quantum mechanics (SQM) method and PQS program. The obtained structures were analyzed with the Atoms in Molecules (AIMs) methodology. The computational results diagnose the most stable conformer of iso-NANO as the Rot-I form. Total density of state (TDOS) and partial density of state (PDOS) and also overlap population density of state (OPDOS) diagrams analysis for the most stable conformer (Rot-I) were calculated using the same method. Thermodynamic properties (heat capacity, entropy and enthalpy) of the title compound at different temperatures were calculated. As a result, the optimized geometry and calculated spectroscopic data show a good agreement with the experimental results.

  5. Acid-base properties, FT-IR, FT-Raman spectroscopy and computational study of 1-(pyrid-4-yl)piperazine

    Science.gov (United States)

    Mary, Y. Sheena; Panicker, C. Yohannan; Varghese, Hema Tresa; Van Alsenoy, Christian; Procházková, Markéta; Ševčík, Richard; Pazdera, Pavel

    2014-03-01

    We report the vibrational spectral analysis was carried out using FT-IR and FT-Raman spectroscopy for 1-(pyrid-4-yl)piperazine (PyPi). Single crystals of PyPi suitable for X-ray structural analysis were obtained. The acid-base properties are also reported. PyPi supported on a weak acid cation-exchanger in the single protonated form and this system can be used efficiently as the solid supported analogue of 4-N,N-dimethyl-aminopyridine. The complete vibrational assignments of wavenumbers were made on the basis of potential energy distribution. The HOMO and LUMO analysis is used to determine the charge transfer within the molecule and with the molecular electrostatic potential map was applied for the reactivity assessment of PyPi molecule toward proton, electrophiles and nucleopholes as well. The stability of the molecule arising from hyper-conjugative interaction and charge delocalization has been analyzed using NBO analysis. The calculated first hyperpolarizability of PyPi is 17.46 times that of urea.

  6. Pressure effects on the structure, kinetic, and thermodynamic properties of heat-induced aggregation of protein studied by FT-IR spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Taniguchi, Y [Applied Chemistry Department, Ritsumeikan University, Kusatsu, Shiga 525-8577 (Japan); Okuno, A [Research Department 3, Central Research, Bridgestone Co. Kodaira, Tokyo 187-8531 (Japan); Kato, M, E-mail: taniguti@sk.ritsumei.ac.j [Pharmaceutical Sciences Department, Ritsumeikan University, Kusatsu, Shiga 525-8577 (Japan)

    2010-03-01

    Pressure can retrain the heat-induced aggregation and dissociate the heat-induced aggregates. We observed the aggregation-preventing pressure effect and the aggregates-dissociating pressure effect to characterize the heat-induced aggregation of equine serum albumin (ESA) by FT-IR spectroscopy. The results suggest the {alpha}-helical structure collapses at the beginning of heat-induced aggregation through the swollen structure, and then the rearrangement of structure to the intermolecular {beta}-sheet takes place through partially unfolded structure. We determined the activation volume for the heat-induced aggregation ({Delta}V'' = +93 ml/mol) and the partial molar volume difference between native state and heat-induced aggregates ({Delta}V=+32 ml/mol). This positive partial molar volume difference suggests that the heat-induced aggregates have larger internal voids than the native structure. Moreover, the positive volume change implies that the formation of the intermolecular {beta}-sheet is unfavorable under high pressure.

  7. Using attenuated total reflection Fourier transform infrared spectroscopy (ATR FT-IR) to study the molecular conformation of parchment artifacts in different macroscopic states.

    Science.gov (United States)

    Gonzalez, Lee; Wade, Matthew; Bell, Nancy; Thomas, Kate; Wess, Tim

    2013-02-01

    Maintaining appropriate temperatures and relative humidity is considered essential to extending the useful life of parchment artifacts. Although the relationship between environmental factors and changes to the physical state of artifacts is reasonably understood, an improved understanding of the relationship between the molecular conformation and changes to the macroscopic condition of parchment is needed to optimize environmental conditions. Using Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR FT-IR) analysis, the conformation of the molecular structure in selected parchment samples with specific macroscopic conditions, typically discoloration and planar deformations (e.g., cockling and tearing), have been made. The results of this investigation showed that the Fourier transform infrared signal differs for parchment samples exhibiting different macroscopic conditions. In areas exhibiting planar deformation, a change in the Fourier Transform Infrared signal was observed that indicates unfolding of the molecular conformation. In comparison, the discolored samples showed a change in molecular conformation that indicates a chemical change within the collagen molecular structure. This paper discusses the possible causal associations and implications of these findings for the conservation and preservation of parchment artifacts.

  8. Combined experimental and quantum chemical studies on spectroscopic (FT-IR, FT-Raman, UV-Vis, and NMR) and structural characteristics of quinoline-5-carboxaldehyde

    Science.gov (United States)

    Kumru, Mustafa; Altun, Ahmet; Kocademir, Mustafa; Küçük, Vesile; Bardakçı, Tayyibe; Şaşmaz, İbrahim

    2016-12-01

    Comparative experimental and theoretical studies have been performed on the structure and spectral (FT-IR, FT-Raman, UV-Vis and NMR) features of quinoline-5-carboxaldehyde. Quantum chemical calculations have been carried out at Hartree-Fock and density functional B3LYP levels with the triple-zeta 6-311++G** basis set. Two stable conformers of quinoline-5-carboxaldehyde arising from the orientation of the carboxaldehyde moiety have been located at the room temperature. The energetic separation of these conformers is as small as 2.5 kcal/mol with a low transition barrier (around 9 kcal/mol). Therefore, these conformers are expected to coexist at the room temperature. Several molecular characteristics of quinoline-5-carboxaldehyde obtained through B3LYP and time-dependent B3LYP calculations, such as conformational stability, key geometry parameters, vibrational frequencies, IR and Raman intensities, UV-Vis vertical excitation energies and the corresponding oscillator strengths have been analyzed. The 1H and 13C NMR chemical shifts of quinoline-5-carboxaldehyde were also investigated.

  9. FT-IR, FT-Raman and computational study of (E)-N-carbamimidoyl-4-((4-methoxybenzylidene)amino)benzenesulfonamide.

    Science.gov (United States)

    Chandran, Asha; Varghese, Hema Tresa; Mary, Y Sheena; Panicker, C Yohannan; Manojkumar, T K; Van Alsenoy, Christian; Rajendran, G

    2012-06-15

    The FT-IR and FT-Raman spectra of (E)-N-carbamimidoyl-4-((4-methoxybenzylidene)amino)benzenesulfonamide were recorded and analyzed. Geometry and harmonic vibrational wavenumbers were calculated theoretically using Gaussian 03 set of quantum chemistry codes. Calculations were performed at the Hartree-Fock (HF) and density functional theory (DFT) levels of theory. The calculated wavenumbers (B3LYP) agree well with the observed wavenumbers. Potential energy distribution is done using GAR2PED program. The red shift of the N-H stretching bands in the infrared spectrum from the computed wavenumber indicates the weakening of the N-H bond. The calculated first hyperpolarizability is comparable with the reported value of similar derivative and may be an attractive object for further studies of nonlinear optics. The variations in the CN bond lengths of the title molecule suggest an extended π-electron delocalization over the sulfaguanidine moiety which is responsible for the nonlinearity of the molecule. The geometrical parameters of the title compound are in agreement with that of reported similar derivatives. Copyright © 2012 Elsevier B.V. All rights reserved.

  10. FT-IR, FT-Raman and UV spectroscopic investigation, electronic properties, electric moments, and NBO analysis of anethole using quantum chemical calculations.

    Science.gov (United States)

    Sinha, L; Prasad, O; Chand, S; Sachan, A K; Pathak, S K; Shukla, V K; Karabacak, M; Asiri, A M

    2014-12-10

    FT-IR and FT-Raman spectra of anethole (1-Methoxy-4-(1-propenyl)benzene), a flavoring agent of commercial value, have been recorded in the regions 4000-400 and 4000-100cm(-1) respectively. The structure of the title molecule has been optimized and the structural parameters have been calculated by DFT/B3LYP method with 6-311++G(d,p) basis set. The fundamental vibrational wavenumbers as well as their intensities were calculated and a good agreement between observed and scaled calculated wavenumbers has been achieved. UV-Vis spectrum of the title compound was recorded in the region 200-500nm and the electronic properties such as HOMO and LUMO energies and associated energy gap were calculated by Time dependent-density functional theory (TD-DFT) approach. Nonlinear optical (NLO) study divulges the nonlinear properties of the molecule. Stability of the title molecule arising from hyper-conjugative interactions and charge delocalization has been investigated using natural bond orbital (NBO) analysis. The theoretical results were found to be in coherence with the measured experimental data. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. Análise por FT-IR (UATR e PAS de microbicidas em filmes poliméricos de tintas comerciais

    Directory of Open Access Journals (Sweden)

    Ricardo Pedro

    2014-01-01

    Full Text Available Este trabalho mostra a avaliação de duas técnicas de espectroscopia no infravermelho por transformada de Fourier (FT-IR, Universal Reflexão Total Atenuada (UATR e Detecção Fotoacústica (PAS, para a caracterização dos microbicidas, OIT, carbendazim e diuron, mais comuns em tintas acrílicas imobiliárias, levando-se em conta as características de cada técnica de análise de superfície tal como a profundidade de amostragem, sob o aspecto qualitativo. A análise PAS, utilizando-se a velocidade de 0,20 cm.s- 1, mostrou-se a única adequada ao estudo. A presença dos microbicidas na película de tinta seca foi, também, confirmada por meio de análises microbiológicas e HPLC.

  12. Quantum mechanical, spectroscopic studies (FT-IR, FT-Raman, NMR, UV) and normal coordinates analysis on 3-([2-(diaminomethyleneamino) thiazol-4-yl] methylthio)-N'-sulfamoylpropanimidamide

    Science.gov (United States)

    Muthu, S.; Uma Maheswari, J.; Sundius, Tom

    2013-05-01

    Famotidine (3-([2-(diaminomethyleneamino) thiazol-4-yl] methylthio)-N'-sulfamoylpropanimidamide) is a histamine H2-receptor antagonist that inhibits stomach acid production, and it is commonly used in the treatment of peptic ulcer disease (PUD) and gastroesophageal reflux disease (GERD/GORD). Quantum chemical calculations of the equilibrium geometry of famotidine in the ground state were carried out using density functional theory (DFT/B3LYP) with the 6-311G(d,p) basis set. In addition, harmonic vibrational frequencies, infrared intensities and Raman activities were calculated at the same level of theory. A detailed interpretation of the infrared and Raman spectrum of the drug is also reported. Theoretical simulations of the FT-IR, and FT-Raman spectra of the title compound have been calculated. Good correlations between the experimental 1H and 13C NMR chemical shifts and calculated GIAO shielding tensors were found. The results of the energy and oscillator strength calculations by time-dependent density functional theory (TD-DFT) supplement the experimental findings. Total and partial density of state (TDOS and PDOS) and also overlap population density of state (COOP or OPDOS) diagrams analysis were presented. The dipole moment, linear polarizability and first order hyperpolarizability values were also computed. The linear polarizability and first order hyperpolarizabilities of the studied molecule indicate that the compound is a good candidate for nonlinear optical materials.

  13. Vibrational frequency analysis, FT-IR, DFT and M06-2X studies on tert-Butyl N-(thiophen-2yl)carbamate

    Science.gov (United States)

    Sert, Yusuf; Singer, L. M.; Findlater, M.; Doğan, Hatice; Çırak, Ç.

    2014-07-01

    In this study, the experimental and theoretical vibrational frequencies of a newly synthesized tert-Butyl N-(thiophen-2yl)carbamate have been investigated. The experimental FT-IR (4000-400 cm-1) spectrum of the molecule in the solid phase have been recorded. The theoretical vibrational frequencies and optimized geometric parameters (bond lengths and bond angles) have been calculated by using density functional theory (DFT/B3LYP: Becke, 3-parameter, Lee-Yang-Parr) and DFT/M06-2X (the highly parametrized, empirical exchange correlation function) quantum chemical methods with the 6-311++G(d,p) basis set by Gaussian 09W software, for the first time. The vibrational frequencies have been assigned using potential energy distribution (PED) analysis by using VEDA 4 software. The computational optimized geometric parameters and vibrational frequencies have been found to be in good agreement with the corresponding experimental data, and with related literature results. In addition, the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) energies and the other related molecular energy values have been calculated and are depicted.

  14. Attenuated Total Reflection Fourier Transform Infrared Spectroscopy (ATR FT-IR) Applied to Study the Distribution of Ink Components in Printed Newspapers.

    Science.gov (United States)

    Gómez, Nuria; Molleda, Cristina; Quintana, Ester; Carbajo, José M; Rodríguez, Alejandro; Villar, Juan C

    2016-09-01

    A new method was developed to study how the oil and cyan pigments of cold-set ink are distributed in newspaper thickness. The methodology involved laboratory printing followed by delamination of the printed paper. The unprinted side, printed side, and resulting layers were analyzed using attenuated total reflection Fourier transform infrared spectroscopy (ATR FT-IR). Three commercial newspapers and black and cyan cold-set inks were chosen for the study. Attenuated total reflection Fourier transform infrared spectroscopy enabled the proportion of oil and cyan pigment on the printed surface and throughout the sheet thickness to be measured. Oil percentage was evaluated as the area increment of the region from 2800 cm(-1) to 3000 cm(-1) The relative amount of cyan pigment was determined as the area of the absorption band at 730 cm(-1) The ink oil was found mainly below half the paper thickness, whereas the pigment was detected at the layers closer to the printed surface, at a depth penetration of less than 15 µm (20% of thickness). Distribution of these two components in paper thickness depended on the type of cold-set ink, the amount of ink transferred, and the newspaper properties.

  15. Conformational stability, spectroscopic (FT-IR, FT-Raman and UV-Vis) analysis, NLO, NBO, FMO and Fukui function analysis of 4-hexylacetophenone by density functional theory.

    Science.gov (United States)

    Saravanan, S; Balachandran, V

    2015-03-05

    The experimental and theoretical study on the structures and vibrations of 4-hexylacetophenone (abbreviated as 4HAP) are presented. The FT-IR and FT-Raman spectra of the title compound have been recorded in the region 4000-400cm(-1) and 3500-100cm(-1) respectively. The molecular structures, vibrational wavenumbers, infrared intensities and Raman activities were calculated using DFT (B3LYP and LSDA) method with 6-311++G(d,p) basis set. The most stable conformer of 4HAP is identified from the computational results. The assignments of the vibrational spectra have been carried out with the aid of normal coordinate analysis (NCA) following the scaled quantum mechanical force field methodology (SQMEF). The linear polarizability (α) and the first hyperpolarizability (βtot) values of the investigated molecule have been computed using B3LYP and LSDA with 6-311++G(d,p) basis set. Stability of the molecule arising from hyper conjugative interaction and charge transfer delocalization has been analyzed using natural bond orbital (NBO) analysis. The molecule orbital contributions are studied by density of energy states (DOSs). UV-Vis spectrum and effects of solvents have been discussed effects of solvents have been discussed and the electronic properties such as HOMO and LUMO energies were determined by time-dependent TD-DFT approach. Fukui function and Mulliken analysis on atomic charges of the title compound have been calculated. Finally, electrophilic and nucleophilic descriptors of the title molecule have been calculated.

  16. Speciation of organic matter in sandy soil size fractions as revealed by analytical pyrolysis (Py-GC/MS) and FT-IR spectroscopy

    Science.gov (United States)

    Jiménez-Morillo, Nicasio T.; González-Vila, Francisco J.; Jordán, Antonio; Zavala, Lorena M.; de la Rosa, José M.; González-Pérez, José A.

    2015-04-01

    This research deals with the assessment of organic matter structural differences in soil physical fractions before and after lipid extractions. Soil samples were collected in sandy soils, Arenosols (WRB 2006) from the Doñana National Park (SW Spain) under different vegetation cover: cork oak (Quercus suber, QS), eagle fern (Pteridium aquilinum, PA), pine (Pinus pinea, PP) and rockrose (Halimium halimifolium, HH). Two size fractions; coarse (C: 1-2 mm) and fine (F: 0.05-0.25 mm) were studied from each soil. . In addition, the two fractions from each soil were exhaustively Soxhlet extracted with a Dichlorometane-Methanol (3:1) mixture to obtain the lipid-free fractions (LF) from each size fraction (LFC and LFF). The composition of the organic matter at a molecular level in the different soil fractions was approached by analytical pyrolysis (Py-GC/MS) and FT-IR spectroscopy. These techniques are complementary and have been found suitable for the structural characterization of complex organic matrices (Moldoveanu, 1998; Piccolo and Stevenson, 1982); whereas Py-GC/MS provides detailed structural information of individual compounds present and a finger-printing of soil organic matter, FT-IR is informative about major functional groups present. The advantages of these techniques are well known: no need for pretreatment are fast to perform, highly reproducible and only small amount of samples are needed. Soil size fractions show contrasting differences in organic matter content (C 4-7 % and F > 40 %) and conspicuous differences were found in the pyrolysis products released by the fractions studied. The main families of pyrolysis compounds have well defined macromolecular precursors, such as lignin, polypeptides, polysaccharides and lipids (González-Vila et al., 2001). The C fractions yield higher relative abundance of lignin and polysaccharide derived pyrolysis compounds. Regarding the differences in the soil organic matter as affected by the different vegetation covers

  17. Probing the role of chemical enhancers in facilitating drug release from patches: Mechanistic insights based on FT-IR spectroscopy, molecular modeling and thermal analysis.

    Science.gov (United States)

    Song, Wenting; Quan, Peng; Li, Shanshan; Liu, Chao; Lv, Siji; Zhao, Yongshan; Fang, Liang

    2016-04-10

    In patches, a drug must release from patches prior to its percutaneous absorption. Chemical enhancers have been used for several decades, but their roles in drug release from patches are poorly understood. In this work, the roles of chemical enhancers in bisoprolol tartrate (BSP-T) release from patches were probed in vitro and in vivo. More importantly, an innovative mechanism insight of chemical enhancers in drug release process was provided at molecular level. FT-IR spectroscopy and molecular modeling were employed to investigate the influence of chemical enhancers on drug-adhesive interaction. The results showed chemical enhancers like Span 80, which had a strong ability forming hydrogen bonds, could decrease drug-adhesive interaction leading to the release of drug from adhesive of patches. Thermal analysis was conducted to research the influence of chemical enhancers on the thermodynamic properties of patch system. It showed that chemical enhancers promoted the formation of free volume of adhesive, which facilitated drug release process. By contrast, the influence on the thermodynamic properties of BSP-T was less effective in influencing BSP-T release process. In conclusion, chemical enhancers played an important role in facilitating BSP-T release from the adhesive DURO-TAK® 87-2287 of patches by decreasing drug-adhesive interaction and promoting the formation of free volume of adhesive. This work may be an important step in understanding the important roles of chemical enhancers in drug release process.

  18. Structural, spectroscopic (FT-IR, NMR, UV-visible), nonlinear optical (NLO), cytotoxic and molecular docking studies of 4-nitro-isonitrosoacetophenone (ninapH) by DFT method

    Science.gov (United States)

    Kucuk, Ilhan; Kaya, Yunus; Kaya, A. Asli

    2017-07-01

    (4-Nitro-phenyl)-oxo-acetaldehyde oxime (ninapH) is a type of oxime, which has a oxime and α-carbonyl groups. This molecule has been synthesized from literature procedure. The structural properties and conformational behaviors were examined using the density functional theory (DFT) with the B3LYP method combined with the 6-311++G(d,p) basis set. As a result of the conformational studies, the most stable conformer was determined, and then this molecule was optimized with the same basis set. Comprehensive theoretical and experimental structural studies on the molecule have been carried out by FT-IR, NMR and UV-vis spectrometry. The calculated HOMO and LUMO energies show that charge transfer within the molecule. The first order hyperpolarizability and molecular electrostatic potential (MEP) were also performed. The thermodynamic properties (heat capacity, entropy, and enthalpy) of the ninapH have been calculated at different temperatures, 100-1000 K. In addition, the molecular docking studies have been performed with DNA and protein structures (downloaded from Protein Data Bank).

  19. GC-MS and FT-IR analysis of a coastal medicinal plant-Hyptis suaveolens (L. Poit

    Directory of Open Access Journals (Sweden)

    Joselin Joseph

    2016-05-01

    Full Text Available Objective: To investigate the bioactive components of a coastal medicinal plant, Hyptis suaveolens (L. Poit. (H. suaveolens leaves using fourier transform-infrared spectroscopy and gas chromatography-mass spectrometer (GC-MS. Methods: The chemical compositions of the ethanol extract of whole plant of H. suaveolens was investigated using PerkinElmer GC-MS, while the mass spectra of the compounds found in the extract was matched with the National Institute of Standard and Technology library. Results: The results of fourier transform-infrared spectroscopy analysis confirmed the presence of secondary alcohols, phenols, alkanes, alkynes, aromatics, nitro compounds and aliphatic compounds. GC-MS analysis of the ethanolic extract revealed the existence of 30 phytochemical compounds. 5,5-Dimethylimidazolidin-2,4-diamine (20.35% was found to be the major compound. Conclusions: The results of this study offer a platform to use H. suaveolens leaves as herbal alternative for various diseases.

  20. GC-MS and FT-IR analysis of a coastal medicinal plant-Hyptis suaveolens (L.) Poit

    Institute of Scientific and Technical Information of China (English)

    Joselin Joseph; Solomon Jeeva

    2016-01-01

    Objective:To investigate the bioactive components of a coastal medicinal plant,Hyptis suaveolens (L.) Poit. (H. suaveolens) leaves using fourier transform-infrared spectroscopy and gas chromatography-mass spectrometer (GC-MS). Methods: The chemical compositions of the ethanol extract of whole plant ofH. suaveolens was investigated using PerkinElmerGC-MS, while the mass spectra of the compounds found in the extract was matched with the National Institute of Standard and Technology library. Results: The results of fourier transform-infrared spectroscopy analysis confirmed the presence of secondary alcohols, phenols, alkanes, alkynes, aromatics, nitro compounds and aliphatic compounds.GC-MS analysis of the ethanolic extract revealed the existence of 30 phytochemical compounds. 5,5-Dimethylimidazolidin-2,4-diamine (20.35%) was found to be the major compound. Conclusions: The results of this study offer a platform to useH. suaveolens leaves as herbal alternative for various diseases.

  1. Estudio FT-IR de la superficie de óxidos mixtos de Fe y Ga mediante la adsorción de moléculas prueba

    Directory of Open Access Journals (Sweden)

    Gallardo Amores, J. M.

    2000-06-01

    Full Text Available Several Fe Ga mixed oxide samples denoted as Fe1-xGaxOy (x = 0, 0.20, 0.25, 0.50, 0.80, 0.90 have been synthesised by a conventional coprecipitation method at controlled pH, dried at 90 ºC for 24 hours and calcined at 400 y 800 ºC for 3 hours. All samples were characterised by X-ray diffraction, chemical analyses and thermogravimetry and differential thermal analysis (TG-DTA and FT-IR and UV-VIS spectroscopies. It was found all materials formed a solid solution, α-(Fe,Ga2O3, in the entire Fe/Ga compositional range until 400 ºC. Samples calcined at 800 ºC gave rise to biphasic samples for x > 0.5 due to different structure of the β-Ga2O3 with respect to the α-Fe2O3 one. Surface acidity of samples was studied by pivalonitrile molecule adsorption on the pressed pellet of each material, founding weak Lewis acid in all cases and not being possible distinguish both cation sites on the surface and Brönsted one that increased by increasing Ga content. Methanol molecule was also adsorbed, showing an increase of reactivity for those samples with a little bit of Ga content.

    Se han sintetizado varias muestras de óxidos mixtos de Fe y Ga con estequiometría Fe1-xGaxOy (x = 0, 0.20, 0.25, 0.50, 0.80, 0.90 mediante un método convencional de coprecipitación a pH controlado, secado a 90 ºC y calcinación a 400 y 800 ºC durante 3 horas. Todas las muestras se caracterizaron mediante difracción de rayos X, análisis químico, análisis térmicos (TG-ATD, espectroscopías FT-IR y VIS-UV. Se encontró que las muestras formaban una solución sólida α-(Fe,Ga2O3 en todo el rango de composiciones Fe/Ga hasta 400 ºC, produciéndose muestras bifásicas a partir de 800 ºC para x > 0.50, debido a la distinta estructura de la β-Ga2O3 respecto a la α-Fe2O3. La acidez se estudió mediante la adsorción de pivalonitrilo sobre pastillas prensadas del propio material, observándose acidez tipo Lewis débil no siendo posible distinguir ambos cationes y Br

  2. Vibrational spectroscopy (FT-IR and FT-Raman) investigation, and hybrid computational (HF and DFT) analysis on the structure of 2,3-naphthalenediol.

    Science.gov (United States)

    Shoba, D; Periandy, S; Karabacak, M; Ramalingam, S

    2011-12-01

    The FT-IR and FT-Raman vibrational spectra of 2,3-naphthalenediol (C(10)H(8)O(2)) have been recorded using Bruker IFS 66V spectrometer in the range of 4000-100 cm(-1) in solid phase. A detailed vibrational spectral analysis has been carried out and the assignments of the observed fundamental bands have been proposed on the basis of peak positions and relative intensities. The optimized molecular geometry and vibrational frequencies in the ground state are calculated by using the ab initio Hartree-Fock (HF) and DFT (LSDA and B3LYP) methods with 6-31+G(d,p) and 6-311+G(d,p) basis sets. There are three conformers, C1, C2 and C3 for this molecule. The computational results diagnose the most stable conformer of title molecule as the C1 form. The isotropic computational analysis showed good agreement with the experimental observations. Comparison of the fundamental vibrational frequencies with calculated results by HF and DFT methods. Comparison of the simulated spectra provides important information about the capability of computational method to describe the vibrational modes. A study on the electronic properties, such as absorption wavelengths, excitation energy, dipole moment and Frontier molecular orbital energies, are performed by time dependent DFT approach. The electronic structure and the assignment of the absorption bands in the electronic spectra of steady compounds are discussed. The calculated HOMO and LUMO energies show that charge transfer occurs within the molecule. On the basis of the thermodynamic properties of the title compound at different temperatures have been calculated. The statistical thermodynamic properties (standard heat capacities, standard entropies, and standard enthalpy changes) and their correlations with temperature have been obtained from the theoretical vibrations.

  3. FT-IR, FT-Raman, UV-visible, and NMR spectroscopy and vibrational properties of the labdane-type diterpene 13-epi-sclareol.

    Science.gov (United States)

    Chain, Fernando E; Leyton, Patricio; Paipa, Carolina; Fortuna, Mario; Brandán, Silvia A

    2015-03-05

    In this work, FT-IR, FT-Raman, UV-Visible and NMR spectroscopies and density functional theory (DFT) calculations were employed to study the structural and vibrational properties of the labdane-type diterpene 13-epi-sclareol using the hybrid B3LYP method together with the 6-31G(∗) basis set. Three stable structures with minimum energy found on the potential energy curves (PES) were optimized, and the corresponding molecular electrostatic potentials, atomic charges, bond orders, stabilization energies and topological properties were computed at the same approximation level. The complete assignment of the bands observed in the vibrational spectrum of 13-epi-sclareol was performed taking into account the internal symmetry coordinates for the three structures using the scaled quantum mechanical force field (SQMFF) methodology at the same level of theory. In addition, the force constants were calculated and compared with those reported in the literature for similar compounds. The predicted vibrational spectrum and the calculated (1)H NMR and (13)C NMR chemical shifts are in good agreement with the corresponding experimental results. The theoretical UV-Vis spectra for the most stable structure of 13-epi-sclareol demonstrate a better correlation with the corresponding experimental spectrum. The study of the three conformers by means of the theory of atoms in molecules (AIM) revealed different H bond interactions and a strong dependence of the interactions on the distance between the involved atoms. Furthermore, the natural bond orbital (NBO) calculations showed the characteristics of the electronic delocalization for the two six-membered rings with chair conformations.

  4. Pigment analyses of a portrait and paint box of Turkish artist Feyhaman Duran (1886-1970): the EDXRF, FT-IR and micro Raman spectroscopic studies.

    Science.gov (United States)

    Akyuz, Sevim; Akyuz, Tanil; Emre, Gulder; Gulec, Ahmet; Basaran, Sait

    2012-04-01

    The samples obtained from nine different places of Ataturk portrait (oil on canvas, 86 cm×136 cm) by Feyhaman Duran (1886-1970), one of the famous Turkish painters of the 20th century, together with five pigment samples (two different white, two different yellow and blue), obtained as powders from artist's paint box, were analysed by EDXRF, FT-IR and micro-Raman spectroscopic methods, in order to characterise the pigments used by the artist. Informative Raman signals were not obtained from most of the samples of the portrait, due to huge fluorescence caused by the presence of impurities and organic materials in the samples, however the Raman spectrum of the sample from skin coloured part of the portrait and the pigment samples obtained from the paint box of the artist were found to be very informative to shed light on the determination of the pigments used. Analysis revealed the presences of chrome yellow (PbCrO4), strontium yellow (SrCrO4) and Cadmium yellow (CdS) as yellow, chromium oxides (Cr2O3 and Cr2O3·2H2O) as green, natural red ochre as red, brown ochre as brown and ivory black or bone black (C+Ca3(PO4)2) and manganese oxides (Mn2O3 and MnO2) as black pigments, in the composition of the Ataturk portrait. Lead white (2PbCO3·Pb(OH)2), calcite (CaCO3), barite (BaSO4), zinc white (ZnO) and titanium white (TiO2) were used as extenders to lighten the colours and/or as for ground level painting. Powder pigment samples, obtained from the paint box of artist, were found to be mixed pigments rather than pure ones. Copyright © 2011 Elsevier B.V. All rights reserved.

  5. Spectroscopic (FT-IR, FT-Raman, UV, NMR, NBO, NLO) investigation and molecular docking study of (R)-2-Methylamino-1-Phenylethanol (Halostachine)

    Science.gov (United States)

    Subashini, K.; Govindarajan, R.; Surendran, R.; Mukund, K.; Periandy, S.

    2016-12-01

    FT-IR (4000-400 cm-1) and FT-Raman (4000-100 cm-1) spectra of (R)-2-Methylamino-1-Phenylethanol have been recorded in solid phase, 1H and 13C NMR in deuterated chloroform (CDCl3) phase and UV spectrum (200-400 nm) in solid phase and in ethanol solution. The different conformers of the compound and their minimum energies were studied by potential energy surface scan, using semi-empirical method PM6. The computed wavenumbers obtained from B3LYP and B3PW91 functionals along with 6-311++G (d, p) basis sets were scaled so as to agree with the experimental values and the scaling factors have been reported. All the fundamental modes have been assigned based on the potential energy distribution (PED) values and the structure of the molecule was analyzed in parameters like bond length, bond angle and dihedral angles through B3LYP and B3PW91 functionals along with 6-311++G(d,p) basis set. The values of dipole moment (μ), polarizability (α) and hyper polarizability (β) of the molecule were calculated using which, the non-linear optical property of the molecule has been discussed. The observed HOMO-LUMO mappings reveals the different charge transfer possibilities within the molecule. Natural Bond Orbital analysis was computed and possible transitions were correlated with the electronic transitions. Mulliken charges, electrostatic potential charges and natural charges are also predicted. The theoretical 1H and 13C NMR chemical shifts were computed using B3LYP functionals using 6-311++G (2d, p) basis sets. The temperature dependence of the thermodynamic properties; heat capacity, entropy and enthalpy for the title compound were also determined by B3LYP functionals with 6-311++G (d, p) basis set. Molecular docking study shows that the title compound might exhibit inhibitory activity against Bacillus anthracis (3V5O).

  6. Spectroscopic [FT-IR and FT-Raman] and theoretical [UV-Visible and NMR] analysis on α-Methylstyrene by DFT calculations.

    Science.gov (United States)

    Karthikeyan, N; Joseph Prince, J; Ramalingam, S; Periandy, S

    2015-05-15

    In the present research work, the FT-IR, FT-Raman and (13)C and (1)H NMR spectra of the α-Methylstyrene were recorded. The observed fundamental frequencies in finger print as well as functional group regions were assigned according to their uniqueness region. The Gaussian computational calculations are carried out by HF and DFT (B3LYP and B3PW91) methods with 6-31++G(d,p) and 6-311++G(d,p) basis sets and the corresponding results were tabulated. The impact of the presence of vinyl group in phenyl structure of the compound is investigated. The modified vibrational pattern of the molecule associated vinyl group was analyzed. Moreover, (13)C NMR and (1)H NMR were calculated by using the gauge independent atomic orbital (GIAO) method with B3LYP methods and the 6-311++G(d,p) basis set and their spectra were simulated and the chemical shifts linked to TMS were compared. A study on the electronic and optical properties; absorption wavelengths, excitation energy, dipole moment and frontier molecular orbital energies were carried out. The kubo gap of the present compound was calculated related to HOMO and LUMO energies which confirm the occurring of charge transformation between the base and ligand. Besides frontier molecular orbitals (FMO), molecular electrostatic potential (MEP) was performed. The NLO properties related to Polarizability and hyperpolarizability based on the finite-field approach were also discussed. Crown Copyright © 2015. Published by Elsevier B.V. All rights reserved.

  7. Pigment analyses of a portrait and paint box of Turkish artist Feyhaman Duran (1886-1970): The EDXRF, FT-IR and micro Raman spectroscopic studies

    Science.gov (United States)

    Akyuz, Sevim; Akyuz, Tanil; Emre, Gulder; Gulec, Ahmet; Basaran, Sait

    2012-04-01

    The samples obtained from nine different places of Ataturk portrait (oil on canvas, 86 cm × 136 cm) by Feyhaman Duran (1886-1970), one of the famous Turkish painters of the 20th century, together with five pigment samples (two different white, two different yellow and blue), obtained as powders from artist's paint box, were analysed by EDXRF, FT-IR and micro-Raman spectroscopic methods, in order to characterise the pigments used by the artist. Informative Raman signals were not obtained from most of the samples of the portrait, due to huge fluorescence caused by the presence of impurities and organic materials in the samples, however the Raman spectrum of the sample from skin coloured part of the portrait and the pigment samples obtained from the paint box of the artist were found to be very informative to shed light on the determination of the pigments used. Analysis revealed the presences of chrome yellow (PbCrO4), strontium yellow (SrCrO4) and Cadmium yellow (CdS) as yellow, chromium oxides (Cr2O3 and Cr2O3·2H2O) as green, natural red ochre as red, brown ochre as brown and ivory black or bone black (C + Ca3(PO4)2) and manganese oxides (Mn2O3 and MnO2) as black pigments, in the composition of the Ataturk portrait. Lead white (2PbCO3·Pb(OH)2), calcite (CaCO3), barite (BaSO4), zinc white (ZnO) and titanium white (TiO2) were used as extenders to lighten the colours and/or as for ground level painting. Powder pigment samples, obtained from the paint box of artist, were found to be mixed pigments rather than pure ones.

  8. Organic matter from benthic foraminifera (Ammonia beccarii) shells by FT-IR spectroscopy: A study on Tupilipalem, South east coast of India.

    Science.gov (United States)

    Sreenivasulu, G; Jayaraju, N; Sundara Raja Reddy, B C; Lakshmi Prasad, T; Nagalakshmi, K; Lakshmanna, B

    2017-01-01

    Fourier Transform Infrared Spectroscopy (FTIR) was used to study the variations in organic matters of benthic foraminifera (Ammonia beccarii) from four samples collected from beach environments from brackish environments along Tupilipalem coast (South east coast of India). Common absorption bands were observed as peaks in the range of 3600-3400 cm(-1), 3000-2850 cm(-1), 1750-1740 cm(-1), 1640-1600 cm(-1), 1450-1350 cm(-1), 885-870 cm(-1) and 725-675 cm(-1) in all the shells of Ammonia beccarii. The FTIR spectrum of station-1 represents the presence of alkanes (CH3) and alkyl halide (C-F stretching) with absorptions at the range 1385-1255 and 1350-1150 cm(-1) were observed and ether (C-O stretching) absorption band was observed at stations 1 and 3 with wavenumber of 1115 cm(-1) and 1117 cm(-1) respectively. Alkynes C-H bend was observed at station-1 with the wavenumber of 667.43 cm(-1). The shifting of peak positions in all the samples is could be due to presence of organic matter in the samples. Satellite remote sensing and field observation data revealed that the river mouth at Tupilipalem coast was closed by a sand bar. Consequentially, this waterbody may affect the species diversity. •Positions of the sampling locations were identified using a hand-held Garmin Global Positioning System (GPS).•Foraminifera from the sediment were obtained using a mixture of Bromoform and Acetone.•The functional groups present in the benthic foraminifera shells were recorded in the spectral range of 4000-400 cm(-1) using an FT-IR Spectrophotometer.

  9. Spectroscopic (FT-IR, FT-Raman, UV, NMR, NLO) investigation and molecular docking study of 1-(4-Methylbenzyl) piperazine

    Science.gov (United States)

    Subashini, K.; Periandy, S.

    2017-04-01

    The title compound, 1-(4-Methylbenzyl) piperazine, was analyzed by recording FT-IR (4000-400 cm-1) and FT-Raman (4000-100 cm-1) spectra in solid phase, 1H and 13C NMR in CDCl3 (deuterated chloroform) and UV spectrum (200-400 nm) in solid phase and in ethanol solution. The different conformers of the compound and their minimum energies were studied by potential energy surface scan, using semi-empirical method PM6. Density functional theory (DFT) calculation with 6-311++G (d, p) basis set along with B3LYP and B3PW91 functionals have been used to compute ground state molecular geometries and vibrational frequencies. The assignments of the vibrational spectra have carried out with the help of Potential Energy distribution (PED) analysis. Factor group analysis has also been tabulated. Charge distribution, Frontier Molecular Orbitals, UV-Vis spectra, Molecular Electrostatic Potential (MEP) maps, Non-linear optical (NLO) property and thermodynamic properties of the title compound at different temperatures, were determined using B3LYP functional along with 6-311++G (d, p) basis set. The theoretical 1H and 13C NMR chemical shifts were computed using B3LYP functional with 6-311++G (2d, p) basis sets. Natural Bond orbital analysis were computed and possible transitions were correlated with the electronic transitions. The title compound not only exhibits appreciable dipole moment and hyper polarizability (indicating good NLO properties) but also forms a stable complex with Bacillus cereus, (2HUC), with binding affinity -6.7 kcal/mol through molecular docking, suggesting that, it might exhibit inhibitory activity against Bacillus cereus.

  10. Experimental (X-ray, FT-IR and UV-vis spectra) and theoretical methods (DFT study) of (E)-3-methoxy-2-[(p-tolylimino)methyl]phenol.

    Science.gov (United States)

    Demircioğlu, Zeynep; Albayrak, Çiğdem; Büyükgüngör, Orhan

    2014-07-15

    A suitable single crystal of (E)-3-methoxy-2-[(p-tolylimino)methyl]phenol, formulated as C15H15N1O2, reveals that the structure is adopted to its E configuration about the azomethine C=N double bond. The compound adopts a enol-imine tautomeric form with a strong intramolecular O-H⋯N hydrogen bond. The single crystal X-ray diffraction analysis at 296K crystallizes in the monoclinic space group P21/c with a = 13.4791(11) Å, b = 6.8251(3) Å, c = 18.3561(15) Å, α = 90°, β = 129.296(5)°, γ = 90° and Z = 4. Comprehensive theoretical and experimental structural studies on the molecule have been carried out by FT-IR and UV-vis spectrometry. Optimized molecular structure and harmonic vibrational frequencies have been investigated by DFT/B3LYP method with 6-31G(d,p) basis set. Stability of the molecule, hyperconjugative interactions, charge delocalization and intramolecular hydrogen bond has been analyzed by using natural bond orbital (NBO) analysis. Electronic structures were discussed by TD-DFT method and the relocation of the electron density were determined. The energetic behavior of the title compound has been examined in solvent media using polarizable continuum model (PCM). Molecular electrostatic potential (MEP), Mulliken population method and natural population analysis (NPA) have been studied. Nonlinear optical (NLO) properties were also investigated. In addition, frontier molecular orbitals analysis have been performed from the optimized geometry. An ionization potential (I), electron affinity (A), electrophilicity index (ω), chemical potential (μ), electronegativity (χ), hardness (η), and softness (S), have been investigated.

  11. Optimized data analysis algorithm for on-site chemical identification using a hand-held attenuated total reflection Fourier transform infrared (ATR FT-IR) spectrometer.

    Science.gov (United States)

    Ron, Izhar; Zaltsman, Amalia; Kendler, Shai

    2013-12-01

    On-site identification of organic compounds in the presence of interfering materials using a field-portable attenuated total reflection Fourier transform infrared (ATR FT-IR) spectrometer is presented. Identification is based on an algorithm that compares the analyte's infrared absorption spectrum with the reference spectra. The comparison is performed at several predetermined frequencies, and a similarity value (distance) between the measured and the reference spectra is calculated either at each frequency individually, or, alternatively, the average distance for all frequencies is calculated. The examined frequencies are selected to give the best contrast between the target materials of interest. In this study, the algorithm was optimized to identify three common chemical warfare agents (CWAs): O-ethyl S-[2-(diisopropylamino)ethyl] methylphosphonothioic acid (VX), sarin (GB), and sulfur mustard (bis(2-chloroethyl) sulfide) (HD), in the presence of field-related interfering materials (fuels, water, and dust). Receiver operating characteristics analysis was performed in order to determine the probabilities for detection (PD) and for false alerts (PF). Challenging the algorithm with a set of data that contains mixtures of CWAs and interfering materials resulted in PD of 90% and PF of 0%, 0%, and 1% for VX, GB, and HD, respectively, using the average distance approach, which was found to be much more effective than analyzing each frequency individually. This finding was validated for all possible combinations of 2-7 peaks per material. It is suggested that this algorithm provides a reliable mean for the identification of a predetermined set of target analytes and interfering materials.

  12. FT-IR spectroelectrochemical study of the reduction of 1,4-dinitrobenzene on Au electrode: Hydrogen bonding and protonation in proton donor mixed media

    Energy Technology Data Exchange (ETDEWEB)

    Tian Dexiang [Department of Chemistry, Anhui University, 230039, Hefei, Anhui province (China); Jin Baokang, E-mail: bkjinhf@yahoo.com.cn [Department of Chemistry, Anhui University, 230039, Hefei, Anhui province (China)

    2011-10-30

    Highlights: > 1,4-Dinitrobenzene electrochemical reduction on the Au electrode is explored. > Radical anion (PNB{center_dot}{sup -}) is found both in aprotic media and in proton donors mixed media. > The H-bonding forming between PNB{center_dot}{sup -}, PNB{sup 2-} and proton donors in low donors concentration. > The protonation of PNB{sup 2-} occurs in high concentration proton donor mixed media. - Abstract: The electrochemical behavior of 1,4-dinitrobenzene (1,4-PNB) on the Au electrode was investigated by cyclic voltammetry (CV), in situ FT-IR spectroelectrochemistry, cyclic voltabsorptometry (CVA) and derivative cyclic voltabsorptometry (DCVA) techniques. In aprotic media, 1,4-dinitrobenzene is reversibly reduced in two-step one-electron transfer. A series of IR absorption bands at 1056, 1210, 1341, 1356, 1464 and 1549 cm{sup -1}, tracing to PNB; PNB{center_dot}{sup -} and PNB{sup 2-} are observed. In the presence of proton donors mixed media, with increasing concentrations of proton donors, hydrogen-bonding and protonation process are found successively. The values of combining proton donors with per PNB{sup 2-} to form hydrogen-bonding are estimated by using electrochemical parameters. The result of forming aromatic nitroso compound is supported by tracing the change of IR absorption bands at 1149 and 1587 cm{sup -1} at high concentration of proton donors. Based on CVA and DCVA techniques, it is clearly distinguished that the mechanisms of electrochemical reduction of PNB are elaborated in different systems.

  13. FT-IR, FT-Raman, UV-Visible, and NMR spectroscopy and vibrational properties of the labdane-type diterpene 13-epi-sclareol

    Science.gov (United States)

    Chain, Fernando E.; Leyton, Patricio; Paipa, Carolina; Fortuna, Mario; Brandán, Silvia A.

    2015-03-01

    In this work, FT-IR, FT-Raman, UV-Visible and NMR spectroscopies and density functional theory (DFT) calculations were employed to study the structural and vibrational properties of the labdane-type diterpene 13-epi-sclareol using the hybrid B3LYP method together with the 6-31G∗ basis set. Three stable structures with minimum energy found on the potential energy curves (PES) were optimized, and the corresponding molecular electrostatic potentials, atomic charges, bond orders, stabilization energies and topological properties were computed at the same approximation level. The complete assignment of the bands observed in the vibrational spectrum of 13-epi-sclareol was performed taking into account the internal symmetry coordinates for the three structures using the scaled quantum mechanical force field (SQMFF) methodology at the same level of theory. In addition, the force constants were calculated and compared with those reported in the literature for similar compounds. The predicted vibrational spectrum and the calculated 1H NMR and 13C NMR chemical shifts are in good agreement with the corresponding experimental results. The theoretical UV-Vis spectra for the most stable structure of 13-epi-sclareol demonstrate a better correlation with the corresponding experimental spectrum. The study of the three conformers by means of the theory of atoms in molecules (AIM) revealed different H bond interactions and a strong dependence of the interactions on the distance between the involved atoms. Furthermore, the natural bond orbital (NBO) calculations showed the characteristics of the electronic delocalization for the two six-membered rings with chair conformations.

  14. In Situ FT-IR Spectroscopic Studies of CO Adsorption on Fresh Mo2C/Al2O3 Catalyst.

    Science.gov (United States)

    Wu, Weicheng; Wu, Zili; Liang, Changhai; Chen, Xiaowei; Ying, Pinliang; Li, Can

    2003-07-24

    The surface sites of supported molybdenum carbide catalyst derived from different synthesis stages have been studied by in situ FT-IR spectroscopy using CO as the probe molecule. Adsorbed CO on the reduced passivated Mo2C/Al2O3 catalyst gives a main band at 2180 cm(-1), which can be assigned to linearly adsorbed CO on Mo(4+) sites. The IR results show that the surface of reduced passivated sample is dominated by molybdenum oxycarbide. However, a characteristic IR band at 2054 cm(-1) was observed for the adsorbed CO on MoO3/Al2O3 carburized with CH4/H2 mixture at 1033 K (fresh Mo2C/Al2O3), which can be assigned to linearly adsorbed CO on Mo(δ+) (0 Mo2C/Al2O3. Unlike adsorbed CO on reduced passivated Mo2C/Al2O3 catalyst, the IR spectra of adsorbed CO on fresh Mo2C/Al2O3 shows similarity to that on some of the group VIII metals (such as Pt and Pd), suggesting that fresh carbide resembles noble metals. To study the stability of Mo2C catalyst during H2 treatment and find proper conditions to remove the deposited carbon species, H2 treatment of fresh Mo2C/Al2O3 catalyst at different temperatures was conducted. Partial amounts of carbon atoms in Mo2C along with some surface-deposited carbon species can be removed by the H2 treatment even at 450 K. Both the surface-deposited carbon species and carbon atoms in carbide can be extensively removed at temperatures above 873 K.

  15. Comprehensive GC–FID, GC–MS and FT-IR spectroscopic analysis of the volatile aroma constituents of Artemisia indica and Artemisia vestita essential oils

    Directory of Open Access Journals (Sweden)

    Manzoor A. Rather

    2017-05-01

    Full Text Available In the current study, the leaf volatile constituents of the essential oils of Artemisia indica Willd. and Artemisia vestita Wall were studied using a combination of capillary GC–FID, GC–MS and FT-IR (Fourier-Transform Infra-Red analytical techniques. The analysis led to the identification of 42 compounds in the essential oil of A. indica, representing 96.6% of the essential oil and the major components were found to be artemisia ketone (42.1%, germacrene D (8.6%, borneol (6.1% and cis-chrysanthenyl acetate (4.8%. The essential oil was dominated by the presence of oxygenated monoterpenes constituting 65.2% of the total oil composition followed by sesquiterpene hydrocarbons and monoterpene hydrocarbons constituting 15.7% and 10.7%, respectively of the total oil composition. The essential oil composition of A. vestita was found to contain a total of 18 components representing 94.2% of the total oil composition. The principal components were found to be 1,8-cineole (46.8%, (E-citral (13.7%, limonene (9.8%, α-phellandrene (6.4%, camphor (5.0%, (Z and (E-thujones (3.0% each. Oxygenated monoterpenes were the dominant group of terpenes in the essential oil constituting 73.1% of the total oil composition followed by monoterpene hydrocarbons (17.3%. The results of the current study reveal remarkable differences in the essential oil compositions of these two Artemisia species already reported in the literature from other parts of the globe.

  16. A combined experimental and theoretical studies on FT-IR, FT-Raman and UV-vis spectra of 2-chloro-3-quinolinecarboxaldehyde.

    Science.gov (United States)

    Prasad, M V S; Udaya Sri, N; Veeraiah, V

    2015-09-05

    In the present study, the FT-IR and FT-Raman spectra of 2-chloro-3-quinolinecarboxaldehyde (2Cl3QC) have been recorded in the region 4000-400 and 3500-50 cm(-1), respectively. The fundamental modes of vibrational frequencies of 2Cl3QC are assigned. Theoretical information on the optimized geometry, harmonic vibrational frequencies, infrared and Raman intensities were obtained by means of density functional theory (DFT) gradient calculations with complete relaxation in the potential energy surface using 6-31G(d,p) basis set. The vibrational frequencies which were determined experimentally from the spectral data are compared with those obtained theoretically from DFT calculations. A close agreement was achieved between the observed and calculated frequencies by refinement of the scale factors. The infrared and Raman spectra were also predicted from the calculated intensities. Thermodynamic properties like entropy, heat capacity, zero point energy, have been calculated for the molecule. The predicted first hyperpolarizability also shows that the molecule might have a reasonably good non-linear optical (NLO) behavior. The calculated HOMO-LUMO energy gap reveals that charge transfer occurs within the molecule. Stability of the molecule arising from hyper conjugative interactions, charge delocalization have been analyzed using natural bond orbitals (NBO) analysis. The results show that charge in electron density (ED) in the π(∗) antibonding orbitals and E((2)) energies confirms the occurrence of ICT (intra-molecular charge transfer) within the molecule. UV-visible spectrum of the title molecule has also been calculated using TD-DFT/CAM-B3LYP/6-31G(d,p) method. The calculated energy and oscillator strength almost exactly reproduces reported experimental data.

  17. The spectroscopic (FT-IR, UV-vis), Fukui function, NLO, NBO, NPA and tautomerism effect analysis of (E)-2-[(2-hydroxy-6-methoxybenzylidene)amino]benzonitrile.

    Science.gov (United States)

    Demircioğlu, Zeynep; Kaştaş, Çiğdem Albayrak; Büyükgüngör, Orhan

    2015-03-15

    A new o-hydroxy Schiff base, (E)-2-[(2-hydroxy-6-methoxybenzylidene)amino]benzonitrile was isolated and investigated by experimental and theoretical methodologies. The solid state molecular structure was determined by X-ray diffraction method. The vibrational spectral analysis was carried out by using FT-IR spectroscopy in the range of 4000-400cm(-)(1). Theoretical calculations were performed by density functional theory (DFT) method using 6-31G(d,p) basis set. The results of the calculations were applied to simulated spectra of the title compound, which show excellent agreement with observed spectra. The UV-vis spectrum of the compound was recorded in the region 200-800 nm in several solvents and electronic properties such as excitation energies, and wavelengths were calculated by TD-DFT/B3LYP method. The most prominent transitions were corresponds to π→π∗. Hybrid density functional theory (DFT) was used to investigate the enol-imine and keto-amine tautomers of titled compound. The titled compound showed the preference of enol form, as supported by X-ray and spectroscopic analysis results. The geometric and molecular properties were compaired for both enol-imine and keto-amine forms. Additionally, geometry optimizations in solvent media were performed with the same level of theory by the integral equation formalism polarizable continuum (IEF-PCM). Stability of the molecule arises from hyperconjugative interactions, charge delocalization and intramolecular hydrogen bond has been analyzed using natural bond orbital (NBO) analysis. Mulliken population method and natural population analysis (NPA) have been studied. Also, condensed Fukui function and relative nucleophilicity indices calculated from charges obtained with orbital charge calculation methods (NPA). Molecular electrostatic potential (MEP) and non linear optical (NLO) properties are also examined.

  18. Spectroscopic (FT-IR, FT-Raman, UV, NMR, NLO) investigation, molecular docking and molecular simulation dynamics on 1-Methyl-3-Phenylpiperazine

    Science.gov (United States)

    Subashini, K.; Periandy, S.

    2017-09-01

    The title compound was analyzed, by recording FT-IR (4000-400 cm-1) and FT-Raman (4000-100 cm-1) spectra in solid phase, 1H and 13C NMR in CDCl3 (deuterated chloroform) and UV spectrum (200-400 nm) in solid phase and in ethanol solution. Conformational analysis was done using semi-empirical method PM6. The computed wavenumbers obtained from B3LYP and B3PW91 functionals along with 6-311++G (d, p) basis sets were scaled so as to agree with the experimental values and the scaling factors have been reported. All fundamental modes have been assigned based on the potential energy distribution (PED) values and the structure of the molecule was analyzed in terms of parameters like bond length, bond angle and dihedral angles through B3LYP and B3PW91 functionals along with 6-311++G(d,p) basis set. The observed HOMO-LUMO mappings reveal the different charge transfer possibilities within the molecule. The percentage contribution of a group to each molecular orbital was calculated using Gauss Sum program. Natural bond orbital analysis was computed and possible transition were correlated with the electronic transitions. Mulliken charges, electrostatic potential charges and natural charges are also predicted. The theoretical 1H and 13C NMR chemical shifts were computed using B3LYP functionals using 6-311++G (2d, p) basis sets. The temperature dependence of the thermodynamic properties; heat capacity, entropy and enthalpy for the title compound were also determined by B3LYP functional with 6-311++G (d, p) basis set. Molecular docking study shows that the title compound might exhibit inhibitory activity against Clostridium botulinum (2J3X). The interaction of the ligand (title molecule) with 2J3X for 2 ns duration and radial distribution function have been observed through molecular dynamics simulations.

  19. Quantitative determination and evaluation of Paris polyphylla var. yunnanensis with different harvesting times using UPLC-UV-MS and FT-IR spectroscopy in combination with partial least squares discriminant analysis.

    Science.gov (United States)

    Yang, Yuan-Gui; Zhang, Ji; Zhao, Yan-Li; Zhang, Jin-Yu; Wang, Yuan-Zhong

    2017-07-01

    A rapid method was developed and validated by ultra-performance liquid chromatography-triple quadrupole mass spectroscopy with ultraviolet detection (UPLC-UV-MS) for simultaneous determination of paris saponin I, paris saponin II, paris saponin VI and paris saponin VII. Partial least squares discriminant analysis (PLS-DA) based on UPLC and Fourier transform infrared (FT-IR) spectroscopy was employed to evaluate Paris polyphylla var. yunnanensis (PPY) at different harvesting times. Quantitative determination implied that the various contents of bioactive compounds with different harvesting times may lead to different pharmacological effects; the average content of total saponins for PPY harvested at 8 years was higher than that from other samples. The PLS-DA of FT-IR spectra had a better performance than that of UPLC for discrimination of PPY from different harvesting times. Copyright © 2016 John Wiley & Sons, Ltd.

  20. A new Density Functional Theory (DFT) based method for supporting the assignment of vibrational signatures of mannan and cellulose—Analysis of palm kernel cake hydrolysis by ATR-FT-IR spectroscopy as a case study

    DEFF Research Database (Denmark)

    Barsberg, Søren Talbro; Sanadi, Anand Ramesh; Jørgensen, Henning

    2011-01-01

    method for polysaccharide IR band assignments. Palm kernel cake is enzymatically hydrolyzed and fermented, which targets cellulose and mannan in particular. The DFT method helps to identify their spectral changes and gives new knowledge on their spectral signatures. This method thus provides...... a prerequisite for FT-IR analysis. The removal of mannan is identified and correlates with positional shifts of both the mannan glycosidic linkage vibration at 1180 cm-1 and the 896 cm-1 cellulose exocyclic C6H2 vibration. This indicates a cellulose environment change, and for mannan the theoretical results show...... a decreasing degree of polymerization to be a plausible cause, although others may interfere. Keywords: Cellulose; Mannan; FT-IR; DFT; Molecular modelling; Palm kernel...

  1. Validación del método para la determinación de número de onda por ft-ir en películas de poliestireno

    OpenAIRE

    Herrera-Basurto, Raúl; Mercader-Trejo, F.; Martínez Suárez, F.

    2013-01-01

    Se utilizó la Guía EURACHEM “The Fitness for Purpose of Analytical Methods”1, para realizar la validación del método empleado en la determinación del número de onda de películas de poliestireno. Las películas de poliestireno son patrones utilizados en la calibración de la escala de número de onda de espectrómetros infrarrojos con transformada de Fourier (FT-IR), también son usados para el control de calidad en las determinaciones por FT-IR. La guía señala que tiene como fin pri...

  2. FT-IR光谱在电离辐射作用于微生物研究中的应用%Application of FT-IR Spectroscopy in Study of Biological Effects on Microorganisms Induced by Ionizing Radiation

    Institute of Scientific and Technical Information of China (English)

    刘京华; 黄青

    2012-01-01

    傅里叶变换红外光谱(Fourier transform infrared spectroscopy,FT-IR)是一种很有用的生物分析检测技术,通过FT-IR光谱技术可以得到有关蛋白质、脂类、核酸和多糖等微生物和细胞各类组成成分的信息.基于同步辐射光源的显微FT-IR光谱具有更高的空间分辨率和更快的测量速度,因而在生物学研究中具有进行快速、实时、动态和无损检测等优势.本文介绍了FT-IR光谱技术在微生物及电离辐射作用于微生物引起的生物学效应研究中的应用,并对该领域未来研究的发展趋势进行了展望.%Fourier transform infrared (FT-IR) spectroscopy is a useful and powerful technique that can provide rich information on proteins,lipids,nucleic acids and carbohydrates in biological systems. Especially,the high-resolution synchrotron Fourier-transform infrared (SR-FTIR) microspectroscopy and imaging technique can be employed as an excellent tool for convenient,fast,non-invasive,and real-time monitoring of varied complicated processes occuring in a biological system. In this review,the authors discuss the recent progress on the application of FT-IR spectroscopy in the study of biological effects on microorganisms induced by ionizing radiation,and also give an outlook for the future FT-IR spectroscopy research in this field.

  3. Changes in the aggregation patterns of Z-2,3-diphenylpropenoic acid and its methyl ester on substituting the olefinic hydrogen with CF 3 group—an FT-IR study

    Science.gov (United States)

    Kiss, J. T.; Felföldi, K.; Pálinkó, I.

    2005-06-01

    While in the unsubstituted Z-2,3-diphenylpropenoic acid and its methyl ester the olefinic protons rarely were part of any hydrogen bonding interaction, upon substitution by CF 3 group, the possibility of (aromatic)C-H⋯F intermolecular hydrogen bond appeared and indeed realised for the molecules ( E-2,3-diphenyl-3-CF 3-propenoic acid and its methyl ester) in the solid state. This type of close contact was indicated experimentally by FT-IR spectroscopy.

  4. FT-IR and 1H NMR studies of the state of solubilized water in water-in-oil microemulsions stabilized by mixtures of single- and double-tailed cationic surfactants.

    Science.gov (United States)

    Bumajdad, Ali; Madkour, Metwally; Shaaban, Ehab; El Seoud, Omar A

    2013-03-01

    The structure of solubilized water in water-in-n-heptane aggregates stabilized by mixtures of single- and double-tail quaternary ammonium surfactants, namely didodecyldimethylammonium chloride/dodecyltrimethylammonium chloride (DDAC/DTAC) or didodecyldimethylammonium bromide/dodecyltrimethylammonium bromide (DDAB/DTAB) was studied by two noninvasive techniques, (1)H NMR and FT-IR. In the former, the chemical shift data, δ(obs), were used to calculate the so-called deuterium/protium fractionation factor, φ(M), of the aggregate-solubilized water and were found to be unity. In the FT-IR study, upon increasing water/surfactant molar ratio, W, the frequency, ν(OD), of the HOD species decreases, while its full width at half height and its area increase. The results obtained from both techniques indicate that the water appears to be present as a single nano-phase and the structure varies continuously as a result of increasing W. In addition, the effect of changing the counter-ion (Br(-) or Cl(-)) on (1)H NMR and FT-IR results was investigated. In spite of the known difference in the dissociation of these counter-ions from micellar aggregates, this was found not to affect the state of solubilized water. This report gives further insight into the contradictory scientific debates on the structure of water in the polar nano-cores of microemulsions.

  5. Antimycobacterial, antimicrobial activity, experimental (FT-IR, FT-Raman, NMR, UV-Vis, DSC) and DFT (transition state, chemical reactivity, NBO, NLO) studies on pyrrole-isonicotinyl hydrazine.

    Science.gov (United States)

    Rawat, Poonam; Singh, R N; Ranjan, Alok; Ahmad, Sartaj; Saxena, Rajat

    2017-05-15

    As part of a study of pyrrole hydrazone, we have investigated quantum chemical calculations, molecular geometry, relative energy, vibrational properties and antimycobacterial/antimicrobial activity of pyrrole-2-carboxaldehyde isonicotinyl hydrazone (PCINH), by applying the density functional theory (DFT) and Hartree Fock (HF). Good reproduction of experimental values is obtained and with small percentage error in majority of the cases in comparison to theoretical result (DFT). The experimental FT-IR and Raman wavenumbers were compared with the respective theoretical values obtained from DFT calculations and found to agree well. In crystal structure studies the hydrated PCINH (syn-syn conformer) shows different conformation than from anhydrous form (syn-anti conformer). The rotational barrier between syn-syn and syn-anti conformers of PCINH is 12.7kcal/mol in the gas phase. In this work, use of FT-IR, FT-Raman, (1)H NMR, (13)C NMR and UV-Vis spectroscopies has been made for full characterization of PCINH. A detailed interpretation of the vibrational spectrum was carried out with the aid of normal coordinate analysis using single scaling factor. Our results support the hydrogen bonding pattern proposed by reported crystalline structure. The calculated nature of electronic transitions within molecule found to be π→π*. The electronic descriptors study indicates that PCINH can be used as robust synthon for synthesis of new heterocyclic compounds. The first static hyperpolarizability (β0) of PCINH is calculated as 33.89×10(-30)esu, (gas phase); 68.79×10(-30) (CHCl3), esu; 76.76×10(-30)esu (CH2Cl2), 85.16×10(-30)esu (DMSO). The solvent induced effects on the first static hyperpolarizability were studied and found to increase as dielectric constants of the solvents increases. Investigated molecule shows better NLO value than Para nitroaniline (PNA). The compound PCINH shows good antifungal and antibacterial activity against Aspergillus niger and gram

  6. Determinação quantitativa da concentração de silicone em antiespumantes por espectroscopia FT-IR / ATR e calibração multivariada Quantitative determination of silicone in antifoaming products by FT-IR / ATR spectroscopy and multivariate calibration

    Directory of Open Access Journals (Sweden)

    Marcelo H. F. Garcia

    2004-12-01

    Full Text Available Neste trabalho apresentamos uma alternativa para a dosagem do teor de silicone (polidimetilsiloxano em antiespumantes por meio da técnica de espectroscopia no infravermelho com transformada de Fourier (FT-IR, com a utilização do acessório de reflectância total atenuada (ATR. Os espectros foram registrados na faixa espectral de 2500 a 780 cm-1, com resolução de 4 cm-1 e 128 varreduras. A calibração de um modelo linear por meio da utilização do método de mínimos quadrados parciais (PLS aplicado aos espectros foi capaz de determinar satisfatoriamente a concentração de silicone nas amostras. Este método é de extrema importância para indústrias produtoras de antiespumantes siliconados, uma vez que o desempenho de tais produtos geralmente é avaliado em função da viscosidade dos mesmos. Muitas vezes no processo de fabricação de tais produtos ocorre uma homogeneização incompleta do silicone no solvente, o que leva a resultados de viscosidade que não são representativos das amostras analisadas. A determinação da concentração do teor de silicone é uma importante ferramenta para o Controle Estatístico de Processo (CEP, pois evita o desperdício de matérias-primas empregadas na fabricação dos antiespumantes.This work presents an alternative method to determine the concentration of silicone (polydimethylsiloxane in antifoaming products using Fourier Transformed Infrared Spectroscopy (FT-IR with the attenuated total reflectance (ATR accessory. The spectra were recorded in the range from 2500 to 780 cm-1, with a resolution of 4 cm-1 and 128 scans. With calibration of a linear model using PLS regression method applied to spectral data we were able to determine the silicone concentration in the samples. This method may be useful for antifoaming producers since the performance of such products generally is evaluated as a function of their viscosity. Moreover, during manufacturing an incomplete homogenization of silicone in the

  7. Z-DNA's conformer substates revealed by FT-IR difference spectroscopy of nonoriented left-handed double helical poly(dG-dC).

    Science.gov (United States)

    Rauch, Christine; Pichler, Arthur; Trieb, Michael; Wellenzohn, Bernd; Liedl, Klaus R; Mayer, Erwin

    2005-04-01

    Nonoriented hydrated films of double helical poly(dG-dC) in the Z-form were studied by Fourier transform infrared (FT-IR) spectroscopy either as equilibrated slow-cooled samples between 290 and 220 K or, after quenching into the glassy state, as nonequilibrated film isothermally at 200, 220, and 240 K. IR spectral changes on isothermal relaxation at 200 and 220 K toward equilibrium, caused by interconversion of two conformer substates (CS) called Z1 and Z2, are revealed by IR difference spectra. Pronounced spectral changes on Z1-to-Z2 interconversion occur between approximately 750-1250 cm(-1) and these are attributed to structural changes of the phosphodiester-sugar backbone caused by changes of torsion angles, and to decreasing hydrogen-bonding of the ionic phosphate group with water molecules. These spectral changes on Z1-to-Z2 transition can be related to structural differences between ZI and ZII CS observed in single crystals. ZI/ZII CS occurs only at (dGpdC) base steps, and similar behavior is assumed for Z1/Z2. The Z1/Z2 population ratio was determined via curve resolution of marker bands for Z1 and Z2 centered at 785 and 779 cm(-1). This ratio is 0.64 at 290 K, corresponding to 39% of the phosphates of the (dGpdC) base steps in Z1 and 61% in Z2, and it increases to 1.24 on cooling to 220 K. For the Z2Z1 equilibrium, an enthalpy change of -4.9 +/- 0.2 kJ mol(dGpdC)(-1) is obtained from the temperature dependence of the equilibrium constant. Z1 interconverts into Z2 at isothermal relaxation at 200 and 220 K, whereas on slow cooling from ambient temperature, Z2 interconverts into Z1. This unexpected reversal of CS interconversion is attributed to slow restructuring of hydration shells of the CS on quenching, in the same manner reported by Pichler et al. for the BI and BII CS of B-DNA (J. Phys. Chem. B 106, 3263-3274 (2002)). IR difference curves demonstrate two time scales on isothermal relaxation of Z1-->Z2 interconversion, a fast one for structural

  8. THz and Ft-Ir Study of 18-O Isotopologues of Sulfur Dioxide: 32S16O18O and 32S18O_2

    Science.gov (United States)

    Margulès, L.; Motiyenko, R. A.; Demaison, J.; Perrin, Agnes; Kwabia Tchana, F.; Manceron, Laurent

    2016-06-01

    Sulfur dioxide is a molecule that have a great interest in different domains: for atmospheric and planetology chemistry, it is also ubiquitous and abundant in interstellar medium. If the 16O species were extensively studied, this is not the case of the 18O isotopologues. The aim of this study is first to complete the rotational spectra of the ground state with these new measurements up to 1.5 THz, previous measurements are up to 1050 GHz for the 32S16O18O species, and 145 GHz concerning the 32S18O_2 species. The second part is making a global fit of the rotational and vibrational transitions for the excited vibrational states. For the v_2 band, we will complete the recent I.R. analysis. About the triad (v_1, 2v_2, v_3): 32S18O_2 species was studied, but not the 32S16O18O one. and 145 GHz concerning the 32S18O_2 species. The second part is making a global fit of the rotational and vibrational transitions for the excited vibrational states. For the v_2 band, we will complete the recent I.R. analysis. About the triad (v_1, 2v_2, v_3): 32S18O_2 species was studied, but not the 32S16O18O one. The FT-IR spectra were recorded on the AILES Beamline at Synchrotron SOLEIL using the Synchrotron light source, coupled to the Bruker IFS125HR Fourier transform spectrometer. The THz spectra were obtained from 150 to 1500 GHz using the Lille's solid state spectrometer. The analysis is in progress, the latest results will be presented. Support from the French Laboratoire d'Excellence CaPPA (Chemical and Physical Properties of the Atmosphere) through contract ANR-10-LABX-0005 of the Programme d'Investissements d'Avenir is acknowledged Belov, S. P.; et al., 1998, J. Mol. Spectrosc. 191, 17 Lindermayer, J.; et al., 1985, J. Mol. Spectrosc. 110, 357 Gueye, F.; et al. Mol. Phys. in press Ulenikov, O. N.; et al., 2015, JQSRT 166, 13 Brubach, J.; et al., 2010, AIP Conf. Proc. 1214, 81 Zakharenko, O.; et al., 2015, J. Mol. Spectrosc. 317, 41

  9. Synthesis, electronic structure investigation of 3-pentyl-2,6-di(furan-2-yl)piperidin-4-one by FT-IR, FT-Raman and UV-Visible spectral studies and ab initio/DFT calculations.

    Science.gov (United States)

    Arockia Doss, M; Savithiri, S; Rajarajan, G; Thanikachalam, V; Anbuselvan, C

    2015-12-05

    FT-IR and FT-Raman spectra of 3-pentyl-2,6-di(furan-2-yl) piperidin-4-one (3-PFPO) were recorded in the solid phase. The structural and spectroscopic analyses of 3-PFPO were made by using B3LYP/HF level with 6-311++G(d, p) basis set. The fundamental vibrations are assigned on the basis of the total energy distribution (TED) of the vibrational modes, calculated with scaled quantum mechanics (SQM) method and PQS program. Comparison of the observed fundamental vibrational frequencies of 3-PFPO with calculated results by HF and DFT methods indicates that B3LYP is superior to HF method for molecular vibrational problems. The electronic properties such as excitation energies, oscillator strength, wavelengths and HOMO-LUMO energies were obtained by time-dependent DFT (TD-DFT) approach. The polarizability and first order hyperpolarizability of the title molecule were calculated and interpreted. The hyperconjugative interaction energy (E((2))) and electron densities of donor (i) and acceptor (j) bonds were calculated using NBO analysis. In addition, MEP and atomic charges of carbon, nitrogen, oxygen and hydrogen were calculated using B3LYP/6-311++G(d, p) level theory. Moreover, thermodynamic properties (heat capacities, entropy and enthalpy) of the title compound at different temperatures were calculated in gas phase. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Vibrational spectroscopy (FT-IR and Laser-Raman) investigation, and computational (M06-2X and B3LYP) analysis on the structure of 4-(3-fluorophenyl)-1-(propan-2-ylidene)-thiosemicarbazone.

    Science.gov (United States)

    Sert, Yusuf; Miroslaw, Barbara; Çırak, Çağrı; Doğan, Hatice; Szulczyk, Daniel; Struga, Marta

    2014-07-15

    In this study, the experimental and theoretical vibrational spectral analysis of 4-(3-fluorophenyl)-1-(propan-2-ylidene)-thiosemicarbazone have been carried out. The experimental FT-IR (4000-400 cm(-1)) and Laser-Raman spectra (4000-100 cm(-1)) have been recorded for the solid state samples. The theoretical vibrational frequencies and the optimized geometric parameters (bond lengths and angles) have been calculated for gas phase using density functional theory (DFT/B3LYP: Becke, 3-parameter, Lee-Yang-Parr) and M06-2X (the highly parametrized, empirical exchange correlation function) quantum chemical methods with 6-311++G(d,p) basis set. The diversity in molecular geometry of fluorophenyl substituted thiosemicarbazones has been discussed based on the X-ray crystal structure reports and theoretical calculation results from the literature. The assignments of the vibrational frequencies have been done on the basis of potential energy distribution (PED) analysis by using VEDA4 software. A good correlation was found between the computed and experimental geometric and vibrational data. In addition, the highest occupied (HOMO) and lowest unoccupied (LUMO) molecular orbital energy levels and other related molecular energy values of the compound have been determined using the same level of theoretical calculations.

  11. Avaliação do uso de técnicas FT-IR para caracterização de cobertura polimérica de material energético Evaluation of FT-IR techniques for polymeric coating characterization of energetic material

    Directory of Open Access Journals (Sweden)

    Elizabeth C. Mattos

    2004-06-01

    Full Text Available Técnicas FT-IR de transmissão, reflexão e fotoacústica (PAS foram utilizadas para a caracterização da cobertura polimérica do hexahidro-1,3,5-trinitro-1,3,5-triazina (RDX usando um poliuretano (Estane. Verificou-se no decorrer deste trabalho que, embora seja possível observar as bandas do polímero por meio das diferentes técnicas, as de transmissão (filme vazado e fotoacústica foram aquelas que melhor evidenciaram as absorções do poliuretano na amostra analisada da cobertura polimérica do material energético. Entre as técnicas consideradas de análise de superfície, a espectroscopia PAS apresentou melhor resultado, provavelmente em função da espessura de poucos micra da camada polimérica.The transmission, reflection and photoacoustic FTIR techniques have been used for characterization of polymeric coating of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX using a polyurethane (Estane. Although the bands characteristic of the polymer were indicated by the various techniques, the transmission (casting film and photoacoustic techniques showed better evidence of polyurethane absorptions in the polymer coating of energetic material. Among the surface-sensitive techniques, PAS spectroscopy shows better result, probably because the polymer coating is at few microns from the surface.

  12. FT-IR, UV-vis, 1H and 13C NMR spectra and the equilibrium structure of organic dye molecule disperse red 1 acrylate: a combined experimental and theoretical analysis.

    Science.gov (United States)

    Cinar, Mehmet; Coruh, Ali; Karabacak, Mehmet

    2011-12-01

    This study reports the characterization of disperse red 1 acrylate compound by spectral techniques and quantum chemical calculations. The spectroscopic properties were analyzed by FT-IR, UV-vis, (1)H NMR and (13)C NMR techniques. FT-IR spectrum in solid state was recorded in the region 4000-400 cm(-1). The UV-vis absorption spectrum of the compound that dissolved in methanol was recorded in the range of 200-800 nm. The (1)H and (13)C NMR spectra were recorded in CDCl(3) solution. The structural and spectroscopic data of the molecule in the ground state were calculated using density functional theory (DFT) employing B3LYP exchange correlation and the 6-311++G(d,p) basis set. The vibrational wavenumbers were calculated and scaled values were compared with experimental FT-IR spectrum. A satisfactory consistency between the experimental and theoretical spectra was obtained and it shows that the hybrid DFT method is very useful in predicting accurate vibrational structure, especially for high-frequency region. The complete assignments were performed on the basis of the experimental results and total energy distribution (TED) of the vibrational modes, calculated with scaled quantum mechanics (SQM) method. Isotropic chemical shifts were calculated using the gauge-invariant atomic orbital (GIAO) method. A study on the electronic properties were performed by timedependent DFT (TD-DFT) and CIS(D) approach. To investigate non linear optical properties, the electric dipole moment μ, polarizability α, anisotropy of polarizability Δα and molecular first hyperpolarizability β were computed. The linear polarizabilities and first hyperpolarizabilities of the studied molecule indicate that the compound can be a good candidate of nonlinear optical materials.

  13. Spectroscopic (FT-IR, FT-Raman, NMR and UV-Visible) and quantum chemical studies of molecular geometry, Frontier molecular orbital, NLO, NBO and thermodynamic properties of salicylic acid

    Science.gov (United States)

    Suresh, S.; Gunasekaran, S.; Srinivasan, S.

    2014-11-01

    The solid phase FT-IR and FT-Raman spectra of 2-hydroxybenzoic acid (salicylic acid) have been recorded in the region 4000-400 and 4000-100 cm-1 respectively. The optimized molecular geometry and fundamental vibrational frequencies are interpreted with the aid of structure optimizations and normal coordinate force field calculations based on density functional theory (DFT) method and a comparative study between Hartree Fork (HF) method at 6-311++G(d,p) level basis set. The calculated harmonic vibrational frequencies are scaled and they are compared with experimentally obtained FT-IR and FT-Raman spectra. A detailed interpretation of the vibrational spectra of this compound has been made on the basis of the calculated potential energy distribution (PED). The time dependent DFT method is employed to predict its absorption energy and oscillator strength. The linear polarizability (α) and the first order hyper polarizability (β) values of the investigated molecule have been computed. The electronic properties, such as HOMO and LUMO energies, molecular electrostatic potential (MEP) are also performed. Stability of the molecule arising from hyper conjugative interaction, charge delocalization has been analyzed using natural bond orbital (NBO) analysis.

  14. Synthesis, structural, spectral (FT-IR, FT-Ra, and UV-Vis), thermal, and density functional studies on p-methylaniline complexes of Mn(II), Co(II), and Ni(II) bromides

    Science.gov (United States)

    Bardakçı, Tayyibe; Altun, Ahmet; Golcuk, Kurtulus; Kumru, Mustafa

    2015-11-01

    Transition metal complexes of the form MBr2L2, where M = Mn(II), Co(II) and Ni(II); L = p-methylaniline, were prepared and characterized by elemental and thermogravimetric analyses, magnetic moment measurements, and UV-vis, FT-IR and FT-Raman spectral studies. Geometries, spin-state energetics, and vibrational spectra of the complexes were obtained at the B3LYP/def2-TZVP level. The present experimental and theoretical data suggest 5-coordinate polymeric bromide bridged structure for the Mn complex, distorted tetrahedral structure for the Co complex, and distorted octahedral coordination site for the Ni complex. The experimental FT-IR and FT-Raman bands of the complexes were assigned based on the computational results expressed in terms of internal coordinates with percent potential energy distributions. The vibrational spectra suggest that the coordination occurs via nitrogen atom of p-methylaniline. The thermal characteristics of the complexes indicate that their decompositions start through p-methylaniline.

  15. Spectroscopic (FT-IR, FT-Raman, NMR and UV-Visible) and quantum chemical studies of molecular geometry, Frontier molecular orbital, NLO, NBO and thermodynamic properties of salicylic acid.

    Science.gov (United States)

    Suresh, S; Gunasekaran, S; Srinivasan, S

    2014-11-11

    The solid phase FT-IR and FT-Raman spectra of 2-hydroxybenzoic acid (salicylic acid) have been recorded in the region 4000-400 and 4000-100 cm(-1) respectively. The optimized molecular geometry and fundamental vibrational frequencies are interpreted with the aid of structure optimizations and normal coordinate force field calculations based on density functional theory (DFT) method and a comparative study between Hartree Fork (HF) method at 6-311++G(d,p) level basis set. The calculated harmonic vibrational frequencies are scaled and they are compared with experimentally obtained FT-IR and FT-Raman spectra. A detailed interpretation of the vibrational spectra of this compound has been made on the basis of the calculated potential energy distribution (PED). The time dependent DFT method is employed to predict its absorption energy and oscillator strength. The linear polarizability (α) and the first order hyper polarizability (β) values of the investigated molecule have been computed. The electronic properties, such as HOMO and LUMO energies, molecular electrostatic potential (MEP) are also performed. Stability of the molecule arising from hyper conjugative interaction, charge delocalization has been analyzed using natural bond orbital (NBO) analysis. Published by Elsevier B.V.

  16. Characterization of recombinant human granulocyte colony-stimulating factor expression by FT-IR spectroscopy: Studies on thermal induction and media formulation on the stability of the protein secondary structure.

    Science.gov (United States)

    Vemula, Sandeep; Vemula, Sushma; Dedaniya, Akshay; Kante, Rajesh Kumar; Ronda, Srinivasa Reddy

    2016-08-17

    The Fourier-transform infrared (FT-IR) spectroscopic approach has been employed to understand the recombinant human G-CSF (rhG-CSF) protein accumulation, secondary structure, and thermal stability in Escherichia coli grown under a temperature shift strategy (37 and 28°C) in various media formulations. The choline + sodium pyruvate (37°C) and sodium pyruvate (28°C) formulations have shown the highest inclusion body (IB) accumulation of 0.41 and 0.46 mg/mL, respectively. Furthermore, insights on the structure of the rhG-CSF within IBs and intact cells have been investigated through secondary structure analysis. Thermal stability experiments were also carried out to explain the pattern of the second derivative structure of rhG-CSF. The studies showed that choline + sodium pyruvate formulation has preserved the protein secondary structure even at 82°C. Overall, the FT-IR spectroscopic technique can also be adopted to accelerate the characterization of other recombinant therapeutic proteins of E. coli origin.

  17. Spectroscopic investigations (FT-IR & FT-Raman) and molecular docking analysis of 6-[1-methyl-4-nitro-1H-imidazol-5-yl) sulfonyl]-7H-purine

    Science.gov (United States)

    Prasath, M.; Govindammal, M.; Sathya, B.

    2017-10-01

    The Azathioprine is used as anticancer agent. Azathioprine is chemically called 6-[1-methyl-4-nitro-1H-imidazol-5-yl) sulfonyl]-7H-purine (6M4N5P). The vibrational analysis of the 6M4N5P compound was carried out by using FT-IR and FT-Raman spectroscopic techniques and compared with aspects. The optimized geometry, frequency and intensity of the vibrational bands of 6M4N5P were obtained from the HF and DFT methods with 6-31G (d,p) basis set. The harmonic vibrational frequencies were calculated and the scaled values have been compared with experimental FT-IR and FT-Raman spectra. The calculated Highest Occupied Molecular Orbital (HOMO) and Lowest Unoccupied Molecular Orbital (LUMO) energies show that charge transfer occur within the molecule. MEP (Molecular Electrostatic Potential) is very useful in the investigation of the charge distributions and molecular structure. The molecule orbital contributions were determined by using the total density of states (TDOS). A molecular docking analysis has been carried out to understand the conformational change and electrostatic properties of 6M4N5P in the active site of Rac1-Receptor.

  18. Molecular Orientation and Structural Characterization of Ultrathin Films of C12AzoNaph(1,4)C6N-SDS Studied by FT-IR and NIR-SERS Spectroscopies

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The orientation and structural characterization of the ultrathin film of azobenzene-containing amphiphilic compound, C12AzoNaph(1,4)C6N+Br-, were studied in the present study. The compound can form a stable monolayer with sodium dextrin sulfate(SDS) by means of electrostatic interaction. Fourier-transform infrared(FT-IR) and near-infrared surface-enhanced Raman scattering(NIR-SERS) spectroscopies were used to study the orientation and characterize the structure of the Langmuir-Blodgett(LB) film and the dipping film. The FT-IR spectra indicate that the alkyl tail is nearly perpendicular to the substrate surface without any aggregation and adopts largely trans-zigzag conformation in the LB film. The NIR-SERS spectra demonstrate that the chromorphoric part in C12AzoNaph(1,4)C6N+Br is also nearly perpendicular to the surface of silver substrate both in the dipping film and the LB film. A new "sandwiched system" model was designed to investigate the orientation and structural characterization of the chromophoric part in the multi-monolayer LB films on the non-SERS active substrate. The SERS mechanism of the "sandwiched system" is discussed in the present paper.

  19. Copper(II) and nickel(II) complexes of tetradentate Schiff base ligand: UV-Vis and FT-IR spectra and DFT calculation of electronic, vibrational and nonlinear optical properties

    Science.gov (United States)

    Zarei, Seyed Amir; Khaledian, Donya; Akhtari, Keivan; Hassanzadeh, Keyumars

    2015-11-01

    The experimental fourier transform infrared (FT-IR) and ultraviolet-visible (UV-Vis) spectra of copper(II) and nickel(II) complexes of the deprotonated tetradentate Schiff base ligand N,N‧-bis(2-hydroxybenzylidene)-2,2-dimethyl-1,3-propanediamine (H2L) are compared with their corresponding theoretical ones. The applied theoretical method is based on the density functional theory and time-dependent density functional theory at the UPBE0/PBE0 levels using Def2-TZVP basis set. The computational optimised geometric parameters of the complexes are in good agreement with their corresponding experimental data. The FT-IR and UV-Vis spectra of the complexes were reproduced on the basis of their optimised structures. The vibrational assignments of some fundamental modes of the complexes are performed. The highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) energies are calculated. The analyses of the calculated electronic absorption spectra of the complexes are carried out to elucidate the electronic transitions assignments and their characters. Second-order nonlinear optical property of the complexes is evaluated by the above-mentioned theoretical method that implies much greater values for the complexes in comparison with the corresponding value of urea.

  20. Synthesis, X-ray, NMR, FT-IR, UV/vis, DFT and TD-DFT studies of N-(4-chlorobutanoyl)-N'-(2-, 3- and 4-methylphenyl)thiourea derivatives.

    Science.gov (United States)

    Abosadiya, Hamza M; Anouar, El Hassane; Hasbullah, Siti Aishah; Yamin, Bohari M

    2015-06-05

    A new isomers of thiourea derivatives, namely N-(4-chlorobutanoyl)-N'-(2-methylphenyl)-thiourea (1a), N-(4-chlorobutanoyl)-N'-(3-methylphenyl)thiourea (1b) and N-(4-chlorobutanoyl)-N'-(4-methylphenyl)thiourea (1c) have been synthesized by refluxing mixture of equimolar amounts of 4-chlorobutanoylisothiocyanate with 2, 3 or 4-toluidine, respectively. The three isomers were characterized by spectroscopic (UV/vis, FT-IR and NMR) and X-ray crystallography techniques. To investigate the isomerization effect on spectroscopic data, DFT and TD-DFT calculations have been carried out using five hybrid functionals (B3LYP, B3P86, CAM-B3LYP, M06-2X and PBE0) to predict UV/vis absorption bands (n→π∗ and π→π∗), (1)H and (13)C NMR chemical shifts, FT-IR vibration modes and X-ray parameters (bonds, bond angles and torsion angles) for 1a, 1b and 1c isomers. The results showed that the isomerization effect is significant on λ(MAX) absorption bands, while for IR and NMR the effect is negligible. In accordance with previous studies, B3LYP, B3P86 and PBE0 gave the most reliable to predict the excitation energies of thiourea derivatives.

  1. A theoretical study on the molecular structure and vibrational (FT-IR and Raman) spectra of new organic-inorganic compound [N(C3H7)4]2SnCl6.

    Science.gov (United States)

    Hajlaoui, Sondes; Chaabane, Iskandar; Oueslati, Abderrazak; Guidara, Kamel; Bulou, Alain

    2014-01-03

    Tetrapropylammoniumchloride was used as a ligand for the synthesis of the new organic-inorganic compound bis-tetrapropylammoniumhexachlorostannate. Vibrational study in the solid state was performed by FT-IR of the free Tetrapropylammoniumchloride ligand (TPACL) and by FT-IR and FT-Raman spectroscopies of the [N(C3H7)4]2SnCl6 compound. The comparative analysis of the Infrared spectra of the title compound with that of the free ligand was discussed. The structure of the [N(C3H7)4]2SnCl6 compound was optimized by density functional theory (DFT) using B3LYP method and shows that the calculated values obtained by B3LYP/LanL2MB basis are in much better agreement with the experimental data than those obtained by B3LYP/LanL2DZ. The vibrational frequencies were evaluated using density functional theory (DFT) with the standard B3LYP/LanL2MB basis, and were scaled using various scale factors. Root mean square (RMS) value was calculated and the small difference between experimental and calculated modes has been interpreted by intermolecular interactions in the crystal. Copyright © 2013 Elsevier B.V. All rights reserved.

  2. Synthesis, spectroscopic (UV-Vis, FT-IR and NMR), single crystal XRD of 3,5-diethyl -2,6-di(thiophen-2-yl)piperidin-4-on-1-ium picrate: A comprehensive experimental and computational study

    Science.gov (United States)

    Arockia doss, M.; Rajarajan, G.; Thanikachalam, V.; Selvanayagam, S.; Sridhar, B.

    2017-01-01

    A piperidin-4-one containing picrate 3,5-diethyl -2,6-di(thiophen-2-yl)piperidin-4-on-1-ium picrate [3,5-DPPP] was synthesized. The molecular structure of 3,5-DPPP was confirmed by FT-IR, NMR, Uv-Vis, single crystal XRD analysis and DFT and HF methods with 6-31G(d,p) basis set. The XRD data confirm the transfer of protons from picric acid (O2) to piperidin-4-one ring (N1). The 3,5-DPPP compound is stabilized by the presence of intermolecular and intramolecular hydrogen bonds (N-H⋯O, C-H⋯S and C-H⋯O). Density functional theory and HF calculations have been used widely for calculating a wide variety of molecular properties such as optimized structure, FT-IR and Uv-Vis spectra, and provided reliable results which are in agreement with experimental data. The charge density data have been used to understand the properties of molecular systems. Furthermore, several quantum chemical insights have been obtained in the form of the total and partial density of states, the HOMO-LUMO energy gap and electrostatic potential map etc. In addition, the polarizability and first hyperpolarizability were calculated to show the potential applications of 3,5-DPPP in nonlinear optics.

  3. Nondestructive Handheld Fourier Transform Infrared (FT-IR) Analysis of Spectroscopic Changes and Multivariate Modeling of Thermally Degraded Plain Portland Cement Concrete and its Slag and Fly Ash-Based Analogs.

    Science.gov (United States)

    Leung Tang, Pik; Alqassim, Mohammad; Nic Daéid, Niamh; Berlouis, Leonard; Seelenbinder, John

    2016-05-01

    Concrete is by far the world's most common construction material. Modern concrete is a mixture of industrial pozzolanic cement formulations and aggregate fillers. The former acts as the glue or binder in the final inorganic composite; however, when exposed to a fire the degree of concrete damage is often difficult to evaluate nondestructively. Fourier transform infrared (FT-IR) spectroscopy through techniques such as transmission, attenuated total reflectance, and diffuse reflectance have been rarely used to evaluate thermally damaged concrete. In this paper, we report on a study assessing the thermal damage of concrete via the use of a nondestructive handheld FT-IR with a diffuse reflectance sample interface. In situ measurements can be made on actual damaged areas, without the need for sample preparation. Separate multivariate models were developed to determine the equivalent maximal temperature endured for three common industrial concrete formulations. The concrete mixtures were successfully modeled displaying high predictive power as well as good specificity. This has potential uses in forensic investigation and remediation services particularly for fires in buildings.

  4. Signal-to-noise ratio of FT-IR CO gas spectra

    DEFF Research Database (Denmark)

    Bak, J.; Clausen, Sønnik

    1999-01-01

    that the SNR was at a local minimum at a spectral resolution of 4 cm(-1). As a result of the investigations, we suggest that the specific spectral resolution which smears out the vibrational-rotational line structure of the smaller molecules should be considered to be low (4 cm(-1) for CO)....... simulated signals, and (3) determine the SNR of CO from high to low spectral resolutions related to the molecular linewidth and vibrational-rotational lines spacing. In addition, SNR values representing different spectral resolutions but scaled to equal measurement times were compared. It was found...

  5. Determinação do teor de ENB em EPDM (elastômero puro por FT-IR de transmissão, por meio de banda relativa

    Directory of Open Access Journals (Sweden)

    Denis Damazio

    2015-04-01

    Full Text Available Foi desenvolvida uma metodologia para a determinação do teor de 5-etilideno 2-norboneno (ENB em amostras de borracha (elastômero puro, à base do copolímero de etileno-propileno-dieno (EPDM, por espectroscopia no infravermelho com transformada de Fourier (FT-IR de transmissão, sendo as amostras analisadas, após pirólise controlada e em bico de Bunsen. Embora ambas as técnicas tenham apresentado boa precisão, a realizada por pirólise em bico de Bunsen, com uso de banda e concentração relativa, mostrou-se mais adequada à determinação e ao uso em cálculos complementares de teores de ET e P.

  6. Thiol-thione tautomeric analysis, spectroscopic (FT-IR, Laser-Raman, NMR and UV-vis) properties and DFT computations of 5-(3-pyridyl)-4H-1,2,4-triazole-3-thiol molecule.

    Science.gov (United States)

    Gökce, Halil; Öztürk, Nuri; Ceylan, Ümit; Alpaslan, Yelda Bingöl; Alpaslan, Gökhan

    2016-06-15

    In this study, the 5-(3-pyridyl)-4H-1,2,4-triazole-3-thiol molecule (C7H6N4S) molecule has been characterized by using FT-IR, Laser-Raman, NMR and UV-vis spectroscopies. Quantum chemical calculations have been performed to investigate the molecular structure (thione-thiol tautomerism), vibrational wavenumbers, electronic transition absorption wavelengths in DMSO solvent and vacuum, proton and carbon-13 NMR chemical shifts and HOMOs-LUMOs energies at DFT/B3LYP/6-311++G(d,p) level for all five tautomers of the title molecule. The obtained results show that the calculated vibrational wavenumbers, NMR chemical shifts and UV-vis wavelengths are in a good agreement with experimental data. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Thiol-thione tautomeric analysis, spectroscopic (FT-IR, Laser-Raman, NMR and UV-vis) properties and DFT computations of 5-(3-pyridyl)-4H-1,2,4-triazole-3-thiol molecule

    Science.gov (United States)

    Gökce, Halil; Öztürk, Nuri; Ceylan, Ümit; Alpaslan, Yelda Bingöl; Alpaslan, Gökhan

    2016-06-01

    In this study, the 5-(3-pyridyl)-4H-1,2,4-triazole-3-thiol molecule (C7H6N4S) molecule has been characterized by using FT-IR, Laser-Raman, NMR and UV-vis spectroscopies. Quantum chemical calculations have been performed to investigate the molecular structure (thione-thiol tautomerism), vibrational wavenumbers, electronic transition absorption wavelengths in DMSO solvent and vacuum, proton and carbon-13 NMR chemical shifts and HOMOs-LUMOs energies at DFT/B3LYP/6-311 ++G(d,p) level for all five tautomers of the title molecule. The obtained results show that the calculated vibrational wavenumbers, NMR chemical shifts and UV-vis wavelengths are in a good agreement with experimental data.

  8. Synthesis, structural, spectral (FT-IR, 1H and 13C NMR and UV-Vis), NBO and first order hyperpolarizability analysis of N-(4-nitrophenyl)-2, 2-dibenzoylacetamide by density functional theory

    Science.gov (United States)

    Yalçın, Şerife Pınar; Ceylan, Ümit; Sarıoğlu, Ahmet Oral; Sönmez, Mehmet; Aygün, Muhittin

    2015-10-01

    The title compound, C22H16N2O5, was synthesized and characterized by experimental techniques (FT-IR, 1H NMR, 13C NMR, UV-Vis and X-Ray single crystal determination) and theoretical calculations. The molecular geometry, vibrational frequencies, molecular electrostatic potential (MEP), thermodynamic properties, the dipole moments, HOMO-LUMO energy has been calculated by using the Density Functional Theory (DFT) method with 6-311G(d,p) and 6-311++G(d,p) basis sets. 1H and 13C NMR chemical shifts show good agreement with experimental values. According to calculated results, the 6-311G(d,p) and 6-311++G(d,p) basis sets have showed similar results. The optimized geometry can well reproduce the crystal structure parameters.

  9. Vibrational (FT-IR, FT-Raman) and UV-Visible spectroscopic studies, HOMO-LUMO, NBO, NLO and MEP analysis of Benzyl (imino (1H-pyrazol-1-yl) methyl) carbamate using DFT calculaions

    Science.gov (United States)

    Shankar Rao, Y. B.; Prasad, M. V. S.; Udaya Sri, N.; Veeraiah, V.

    2016-03-01

    This paper contains a combined experimental and theoretical study of vibrational and electronic properties of Benzyl(imino(1H-pyrazol-1-yl)methyl)carbamate (BPMC) molecule. The FT-IR and FT-Raman spectra of the title molecule in solid phase were recorded in the region 4000-400 cm-1 and 4000-50 cm-1, respectively. The UV absorption spectrum of the studied compound dissolved in ethanol was recorded in the range of 180-400 nm. The molecular geometries calculated using density functional theory (DFT) was compared with available experimental data. The vibrational spectra calculated at the B3LYP/6-31G(d,p) level were compared with the experimental spectra and assignment to each vibrational frequency was assigned on the basis of potential energy distribution (PED). The calculated electronic and nonlinear optical properties of the title molecule were reported. Furthermore, the thermodynamic properties of the molecule were discussed.

  10. Analysis of molecular structure, spectroscopic properties (FT-IR, micro-Raman and UV-vis) and quantum chemical calculations of free and ligand 2-thiopheneglyoxylic acid in metal halides (Cd, Co, Cu, Ni and Zn).

    Science.gov (United States)

    Gökce, Halil; Bahçeli, Semiha

    2013-12-01

    In this study, molecular geometries, experimental vibrational wavenumbers, electronic properties and quantum chemical calculations of 2-thiopheneglyoxylic acid molecule, (C6H4O3S), and its metal halides (Cd, Co, Cu, Ni and Zn) which are used as pharmacologic agents have been investigated experimentally by FT-IR, micro-Raman and UV-visible spectroscopies and elemental analysis. Meanwhile the vibrational calculations were verified by DFT/B3LYP method with 6-311++G(d,p) and LANL2DZ basis sets in the ground state, for free TPGA molecule and its metal halide complexes, respectively, for the first time. The calculated fundamental vibrational frequencies for the title compounds are in a good agreement with the experimental data.

  11. Spectroscopic (FT-IR, FT-Raman, 1H, 13C NMR, UV/VIS), thermogravimetric and antimicrobial studies of Ca(II), Mn(II), Cu(II), Zn(II) and Cd(II) complexes of ferulic acid

    Science.gov (United States)

    Kalinowska, M.; Piekut, J.; Bruss, A.; Follet, C.; Sienkiewicz-Gromiuk, J.; Świsłocka, R.; Rzączyńska, Z.; Lewandowski, W.

    2014-03-01

    The molecular structure of Mn(II), Cu(II), Zn(II), Cd(II) and Ca(II) ferulates (4-hydroxy-3-methoxycinnamates) was studied. The selected metal ferulates were synthesized. Their composition was established by means of elementary and thermogravimetric analysis. The following spectroscopic methods were used: infrared (FT-IR), Raman (FT-Raman), nuclear magnetic resonance (13C, 1H NMR) and ultraviolet-visible (UV/VIS). On the basis of obtained results the electronic charge distribution in studied metal complexes in comparison with ferulic acid molecule was discussed. The microbiological study of ferulic acid and ferulates toward Escherichia coli, Bacillus subtilis, Candida albicans, Pseudomonas aeruginosa, Staphylococcus aureus and Proteus vulgaris was done.

  12. Vibrational (FT-IR and FT-Raman), electronic (UV-Vis), NMR (1H and 13C) spectra and reactivity analyses of 4,5-dimethyl-o-phenylenediamine.

    Science.gov (United States)

    Atac, Ahmet; Karaca, Caglar; Gunnaz, Salih; Karabacak, Mehmet

    2014-09-15

    The structure of 4,5-dimethyl-o-phenylenediamine (C8H12N2, DMPDA) was investigated on the basis of spectroscopic data and theoretical calculations. The sterochemical structure was determined by FT-IR, FT-Raman, UV, 1H and 13C NMR spectra. An experimental study and a theoretical analysis were associated by using the B3LYP method with Gaussian09 package program. FT-IR and FT-Raman spectra were recorded in the region of 4000-400 cm(-1) and 4000-10 cm(-1), respectively. The vibrational spectra were calculated by DFT method and the fundamental vibrations were assigned on the basis of the total energy distribution (TED), calculated with scaled quantum mechanics (SQM) method with Parallel Quantum Solutions (PQS) program. The UV absorption spectrum of the compound that dissolved in ethanol solution were recorded in the range of 190-400 nm. Total density of state (TDOS) and partial density of state (PDOS) of the DMPDA in terms of HOMOs and LUMOs were calculated and analyzed. Chemical shifts were reported in ppm relative to tetramethylsilane (TMS) for 1H and 13C NMR spectra. The compound was dissolved in dimethyl sulfoxide (DMSO). Also, 1H and 13C chemical shifts calculated using the gauge independent atomic orbital (GIAO) method. Mullikan atomic charges and other thermo-dynamical parameters were investigated with the help of B3LYP (DFT) method using 6-311++G** basis set. On the basis of the thermodynamic properties of the title compound at different temperatures have been carried out, revealing the correlations between heat capacity (C), entropy (S), enthalpy changes (H) and temperatures. The optimized bond lengths, bond angles, chemical shifts and vibrational wavenumbers showed the best agreement with the experimental results. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Binding of cationic peptides (KX)4K to DPPG bilayers. Increasing the hydrophobicity of the uncharged amino acid X drives formation of membrane bound β-sheets: A DSC and FT-IR study.

    Science.gov (United States)

    Hädicke, André; Blume, Alfred

    2016-06-01

    The binding of cationic peptides of the sequence (KX)4K to lipid vesicles of negatively charged dipalmitoyl-phosphatidylglycerol (DPPG) was investigated by differential scanning calorimetry (DSC) and temperature dependent Fourier-transformed infrared (FT-IR) spectroscopy. The hydrophobicity of the uncharged amino acid X was changed from G (glycine) over A (alanine), Abu (α-aminobutyric acid), V (valine) to L (leucine). The binding of the peptides caused an increase of the phase transition temperature (Tm) of DPPG by up to 20°C. The shift depended on the charge ratio and on the hydrophobicity of the amino acid X. Unexpectedly, the upward shift of Tm increased with increasing hydrophobicity of X. FT-IR spectroscopy showed a shift of the CH2 stretching vibrations of DPPG to lower frequency, particularly for bilayers in the liquid-crystalline phase, indicating an ordering of the hydrocarbon chains when the peptides were bound. Changes in the lipid C=O vibrational band indicated a dehydration of the lipid headgroup region after peptide binding. (KG)4K was bound in an unordered structure at all temperatures. All other peptides formed intermolecular antiparallel β-sheets, when bound to gel phase DPPG. However, for (KA)4K and (KAbu)4K, the β-sheets converted into an unordered structure above Tm. In contrast, the β-sheet structures of (KV)4K and (KL)4K remained stable even at 80°C when bound to the liquid-crystalline phase of DPPG. Strong aggregation of DPPG vesicles occurred after peptide binding. For the aggregates, we suggest a structure, where aggregated single β-sheets are sandwiched between opposing DPPG bilayers with a dehydrated interfacial region.

  14. Spectroscopic (FT-IR, FT-Raman and UV) investigation, NLO, NBO, molecular orbital and MESP analysis of 2-{2-[(2,6-dichlorophenyl)amino]phenyl}acetic acid

    Science.gov (United States)

    Govindasamy, P.; Gunasekaran, S.

    2015-02-01

    In this work, FT-IR and FT-Raman spectra of 2-{2-[(2,6-dichlorophenyl)amino]phenyl}acetic acid (abbreviated as 2DCPAPAA) have been reported in the regions 4000-450 cm-1 and 4000-50 cm-1, respectively. The molecular structure, geometry optimization, intensities, vibrational frequencies were obtained by the ab initio and DFT levels of theory B3LYP with 6-311++G(d,p) standard basis set and a different scaling of the calculated wave numbers. The complete vibrational assignments were performed on the basis of the potential energy distribution (PED) of the vibrational modes calculated using vibrational energy distribution analysis (VEDA 4) program. The harmonic frequencies were calculated and the scaled values were compared with experimental FT-IR and FT-Raman data. The observed and the calculated frequencies are found to be in good agreement. Stability of the molecule arising from hyper conjugative interactions, charge delocalization has been analyzed using natural bond orbital (NBO) analysis. The thermodynamic properties of the title compound at different temperature reveal the correlations between standard heat capacities (C) standard entropies (S) standard enthalpy changes (ΔH). The important non-linear optical properties such as electric dipole momentum, polarizability and first hyperpolarizability of 2DCPAPAA have been computed using B3LYP/6-311++G(d,p) quantum chemical calculations. The Natural charges, HOMO, LUMO, chemical hardness (η), chemical potential (μ), Electro negativity (χ) and electrophilicity values (ω) are calculated and reported. The oscillator's strength, wave length, and energy calculated by TD-DFT and 2DCPAPAA is approach complement with the experimental findings. The molecular electrostatic potential (MESP) surfaces of the molecule were constructed.

  15. Synthesis, spectral (FT-IR, UV-visible, NMR) features, biological activity prediction and theoretical studies of 4-Amino-3-(4-hydroxybenzyl)-1H-1,2,4-triazole-5(4H)-thione and its tautomer

    Science.gov (United States)

    Srivastava, Ambrish Kumar; Kumar, Abhishek; Misra, Neeraj; Manjula, P. S.; Sarojini, B. K.; Narayana, B.

    2016-03-01

    Triazole compounds constitute an important class of organic chemistry due to their various biological and corrosion inhibition activities. The synthesis scheme of a new triazole compound namely, 4-Amino-3-(4-hydroxybenzyl)-1H-1,2,4-triazole-5(4H)-thione (4AHT) has been theoretically analyzed. Our density functional theory (DFT) based calculations show that the synthesis of 4AHT is energetically feasible at the room temperature as the reaction is exothermic, spontaneous as well as favored in forward direction. The calculated bond-lengths are found to be in good agreement with corresponding crystallographic values. We have considered two possible tautomers of 4AHT viz. thione and thiol forms. The FT-IR (KBr disc), UV-visible (ethanol) and 1H-NMR (DMSO) spectra of 4AHT have been recorded. The vibrational modes have been assigned on the basis of their potential energy distributions and scaled wavenumbers agree well with the FT-IR wavenumbers. Time dependent DFT calculations are performed to analyze the electronic transitions for various excited states which reproduce the experimental peak observed in UV-visible spectrum. Using gauge independent atomic orbital method 1H-NMR chemical shifts have been calculated and correlated with the experimental chemical shifts with the linear correlation coefficient of 0.9453. Our spectral analyses reveal the dominance of thione over thiol form of 4AHT. The chemical reactivity of 4AHT has been discussed by molecular electrostatic potential surface as well as various electronic parameters. The biological activities of 4AHT have also been explored theoretically and it has been found that the title molecule can act as a potential inhibitor of cyclin-dependent kinase 5 enzyme. These findings may guide the synthesis and design of new triazole compounds with interesting biological activity.

  16. FT-IR跟踪双酚S/环氧氯丙烷醚化反应动力学%A quantitative FT-IR study of the kinetics of the etherification reaction of bisphenol-S and epichlorohydrin

    Institute of Scientific and Technical Information of China (English)

    张汇萌; 程珏; 尚子扬; 于恒; 林欣; 张军营

    2012-01-01

    The etherification reaction of bisphenol-S (BPS) and epichlorohydrin (ECH) has been studied by a quantitative FT-IR method. The relationship between the changes in the absorption intensities of the FT-IR stretching bands corresponding to phenolic hydroxyl groups and the ether group was studied by regression analysis. The results showed that they have an excellent quadratic function correlation. Based on this result, a standard working curve was set up which could be used to measure the conversion rate of the phenolic hydroxyl group in the etherification reaction of BPS and ECH. This curve was also used in studying the kinetics of the etherification reaction of BPS and ECH. The results showed that the reaction rate is determined by the concentration of the phenolic hydroxyl groups when the ECH is present in large excess. However there is a critical concentration of phenolic hydroxyl groups. When the concentration of the phenolic hydroxyl groups is less than the critical concentration, the reaction follows first order kinetics, with the reaction rate being proportional to the concentration of phenolic hydroxyl groups. However when the concentration of the phenolic hydroxyl groups is greater than the critical concentration, the reaction is zero order, and the reaction has a maximum reaction rate, which is not related to the concentration of phenolic hydroxyl groups.%采用FT-IR跟踪法研究了双酚S与环氧氯丙烷的醚化反应,使用回归分析法研究了醚化物在FT-IR中的醚键特征峰强度与酚羟基转化率之间的关系,结果表明两者间存在良好的二次函数关系.建立了FT-IR法测定醚化反应中酚羟基转化率的标准工作曲线,利用该曲线研究了双酚S与环氧氯丙烷的醚化反应动力学,结果表明,在环氧氯丙烷大大过量的情况下,醚化反应速率与酚羟基浓度相关,当酚羟基浓度小于临界浓度时,该反应为一级反应;当酚羟基浓度大于临界浓度时,该反应为零级反应.

  17. Determination of Acetaminophen in Anti-cold Drugs by Internal Standard Method of FT-IR%抗感冒药中对乙酰氨基酚含量的红外光谱法测定

    Institute of Scientific and Technical Information of China (English)

    何优选; 卢凯; 陈燕娜; 邱冰花; 梁奇峰

    2016-01-01

    建立了红外光谱内标法测定抗感冒药中对乙酰氨基酚的方法。选择铁氰化钾作为内标物,定量添加到对乙酰氨基酚中,在对乙酰氨基酚百分含量为0.16%~1.67%范围内,测得混合物红外光谱中对乙酰氨基酚测量峰(1564.1cm-1)和铁氰化钾内标峰(2117.6cm-1)的峰高比(y=hi/hs)与两者质量比(x=mi/ms)有良好的线性关系,其线性回归方程为y=0.8448x+0.0842,相关系数r=0.9983。据此测得抗感冒药样品中对乙酰氨基酚的含量,测定结果与药典法相近。%A novel method for the determination of acetaminophen in anti-cold drugs by internal standard method of Fourier transform infrared spectrophotometry (FT-IR) was establlished. Potassium ferricyanide was added into acetaminophen as internal reference and the mixtures were detected by FT-IR. The peak of acetaminophen at (1564±1)cm-1 was chosen as quantitative peak and the one of potassium ferricyanide at (2117±1) cm-1 was chosen as inside mark quantitative peak. The ratio of two peak’s absorbance (y=hi/hs ) had good linear relationship with their mass ratio (x=mi/ms) when the mass fraction of acetaminophen was 0.16%~1.67%. The linear regression equation wasy=0.8448x+0.0842, and the linear correlation coefficient was 0.9983. The contents of acetaminophen in the anti-cold drugs sample was detected and the determination results were similar to those of pharmacopoeia method.

  18. Spectral (FT-IR, FT-Raman, UV, and fluorescence), DFT, and solid state interaction analyses of (E)-4-(3,4-dimethoxybenzylideneamino)-1,5-dimethyl-2-phenyl-1H-pyrazol-3(2H)-one

    Science.gov (United States)

    Alam, Mohammad Sayed; Lee, Dong-Ung

    2017-01-01

    Here, the authors report a combined experimental and theoretical study on the molecular structure and vibrational spectral analyses of (E)-4-(3,4-dimethoxybenzylideneamino)-1,5-dimethyl-2-phenyl-1H-pyrazol-3(2H)-one (DMBADPP), a pyrazolone-based bioactive molecule. Density functional theory (DFT) calculations were carried out to obtain the ground state optimized geometry of the molecule using the B3LYP method and the 6-311G(d,p) basis set. Calculated results agreed well with X-ray data. The vibrational spectra of DMBADPP were calculated at the same level of theory and theoretical scaled vibrational frequencies and assignments were found to agree well with experimental FT-IR and FT-Raman values. Partial atomic charge and molecular electrostatic potential (MEP) surface map analyses were performed to study reactive sites. Calculated frontier molecular orbitals (FMOs) energies and chemical reactivity parameters indicated that the DMBADPP exhibits high polarizability and low kinetic susceptibility. Excitation energy, wavelength, and oscillator strength were calculated using the Time Dependant-DFT/B3LYP/6-311G(d,p) method and compared with experimental UV-Vis spectra obtained in ethanol. However, UV-Vis and fluorescence spectroscopic experiments showed that DMBADPP has good absorption and fluorescent properties and a large Stokes shift. In addition, the solid state behaviors of molecules in crystals were analyzed quantitatively and qualitatively using 3D Hirshfeld surface analysis and associated 2D fingerprint plots.

  19. Synthesis, molecular structure and vibrational analysis of D-D-A based carbazole decorated phenothiazine-3-carbaldehyde: Experimental (FT-IR, UV and NMR) and density functional theory (DFT) calculations

    Science.gov (United States)

    Karuppasamy, Ayyanar; Gokula Krishnan, Kannan; Pillai Velayutham Pillai, Muthiah; Ramalingan, Chennan

    2017-01-01

    A novel molecule, 10-(9-hexyl-9H-carbazol-3yl)-10H-phenothiazine-3-carbaldehyde (CZPTZA) has been synthesized and characterized through FT-IR, UV-Vis, NMR spectroscopic studies and molecular orbital calculations. Optimized geometrical structure, harmonic vibrational frequencies and NMR are computed with B3LYP method using 6-311++G (d,p) basis set. The geometrical parameters of the title compound obtained from Single Crystal XRD studies have been found in accord with the calculated (DFT) values. The experimentally observed vibrational frequencies are compared with the calculated ones, which were found to be in good agreement with each other. UV-Vis spectra of the title compound have also been recorded and the electronic properties, viz. excitation energies, calculated energies, oscillator strengths, frontier orbital energies and band gap energies are computed with TD-DFT/CAM-B3LYP method using 6-311++G (d,p) as the basis set. The 1H and 13C NMR chemical shifts of the molecule have been calculated by the Gauge Independent Atomic Orbital (GIAO) method and compared with the experimental outcome. Also, the values of dipole moment, polarizabilities and first order hyperpolarizabilities have been computed.

  20. Spectroscopic investigation (FT-IR and FT-Raman), vibrational assignments, HOMO-LUMO analysis and molecular docking study of 2-(Adamantan-1-yl)-5-(4-nitrophenyl)-1,3,4-oxadiazole

    Science.gov (United States)

    Haress, Nadia G.; Al-Omary, Fatmah; El-Emam, Ali A.; Mary, Y. Sheena; Panicker, C. Yohannan; Al-Saadi, Abdulaziz A.; War, Javeed Ahmad; Van Alsenoy, Christian

    2015-01-01

    FT-IR and FT-Raman spectra of 2-(Adamantan-1-yl)-5-(4-nitrophenyl)-1,3,4-oxadiazole were recorded and analyzed. The vibrational wavenumbers were computed using DFT quantum chemical calculations. The data obtained from wavenumber calculations are used to assign vibrational bands obtained experimentally. The energy barriers of the internal rotations about the Csbnd C bonds connecting the oxadiazole to the adamantane and benzene rings are reported. The geometrical parameters (DFT) of the title compound are in agreement with the XRD results. The calculated HOMO and LUMO energies allow the calculations of atomic and molecular properties and they also showed that charge transfer occurs in the molecule. A detailed molecular picture of the title compound and its interactions were obtained from NBO analysis. As can be seen from the MEP map of the title compound, which regions having the negative potential are over the electro negative atoms, the region having the positive potential are over the phenyl and adamantine rings and the remaining species are surrounded by zero potential. The molecular docking studies reveal that the adamantyl derivative may exhibit C-South African HIV-proteas inhibitory activity.

  1. Normal coordinate analysis and vibrational spectroscopy (FT-IR and FT-Raman) studies of (2S)-2-amino-3-(3,4-dihydroxyphenyl)-2-methylpropanoic acid using ab initio HF and DFT method.

    Science.gov (United States)

    Prabakaran, A; Muthu, S

    2012-12-01

    The FT-IR and FT-Raman spectra of (2S)-2-amino-3-(3,4-dihydroxyphenyl)-2-methylpropanoic acid (2ADMA) were recorded in the region 4000-400 cm(-1) and 4000-100 cm(-1), respectively. The geometrical structure, harmonic vibrational frequency, infrared intensity, Raman activities and bonding features of this compound was carried out by ab initio HF and DFT methods with 6-31G (d,p) basis set. The complete vibrational frequency assignments were made by normal coordinate analysis (NCA) following the scaled quantum mechanical force field methodology (SQMF). The electric dipole moment (μ) and the first-order hyperpolarizability (β(0)) values have been the computed quantum mechanically. The calculated HOMO and LUMO energies show that, the charge transfer occurs within the molecule. The charge delocalizations of these molecules have been analyzed using NBO analysis. The solvent effects have been calculated using TD-DFT in combination with the polarized continuum model (PCM), and the results are in good agreement with experimental measurements. The other molecular properties like Mulliken population analysis, electrostatic potential (ESP) and thermodynamic properties of the title compound at the different temperatures have been calculated. Finally, the calculation results were applied to simulate infrared and Raman spectra of the title compound which shows good agreement with observed spectra.

  2. Attenuated Total Reflection Fourier Transform Infrared (ATR FT-IR) Spectroscopy as a Forensic Method to Determine the Composition of Inks Used to Print the United States One-cent Blue Benjamin Franklin Postage Stamps of the 19th Century.

    Science.gov (United States)

    Brittain, Harry G

    2016-01-01

    Through the combined use of infrared (IR) absorption spectroscopy and attenuated total reflectance (ATR) sampling, the composition of inks used to print the many different types of one-cent Benjamin Franklin stamps of the 19th century has been established. This information permits a historical evaluation of the formulations used at various times, and also facilitates the differentiation of the various stamps from each other. In two instances, the ink composition permits the unambiguous identification of stamps whose appearance is identical, and which (until now) have only been differentiated through estimates of the degree of hardness or softness of the stamp paper, or through the presence or absence of a watermark in the paper. In these instances, the use of ATR Fourier transform infrared spectroscopy (FT-IR) spectroscopy effectively renders irrelevant two 100-year-old practices of stamp identification. Furthermore, since the use of ATR sampling makes it possible to obtain the spectrum of a stamp still attached to its cover, it is no longer necessary to identify these blue Franklin stamps using their cancellation dates.

  3. Normal coordinate analysis and vibrational spectroscopy (FT-IR and FT-Raman) studies of 5-methyl-N-[4-(trifluoromethyl) phenyl]-isoxazole-4-carboxamide using density functional method.

    Science.gov (United States)

    Shahidha, R; Muthu, S; Elamurugu Porchelvi, E; Govindarajan, M

    2014-11-11

    Vibrational spectral analysis of 5-methyl-N-[4-(trifluoromethyl) phenyl]-isoxazole-4-carboxamide is (5MN4TPI4C) molecule was carried out using FT-IR and FT-Raman spectroscopic techniques. The equilibrium geometry, harmonic vibrational wavenumbers, various bonding features have been computed using density functional B3LYP method with 6-311G(d,p) as basis set. The assignments of the vibrational spectra have been carried out with the aid of normal coordinate analysis (NCA) following the scaled quantum mechanical force field methodology (SQMFFM). Stability of the molecule arising from hyper conjugative interactions, charge delocalization has been analyzed using natural bond orbital (NBO) analysis. The non-linear optical (NLO) behavior of 5MN4TPI4C has been studied by determination of the electric dipole moment (μ) and hyperpolarizability (β) by using B3LYP/6-311G(d,p) method. The molecular orbital compositions and their contributions to the chemical bonding are studied by Total density of energy states (TDOS), sum of α and β electron (αβDOS) density of states. Thermodynamic properties (heat capacity, entropy and enthalpy) of the title compound at different temperatures are calculated.

  4. Molecular structure, spectroscopic (FT-IR, FT-Raman, NMR, UV) studies and first-order molecular hyperpolarizabilities of 1,2-bis(3-methoxy-4-hydroxybenzylidene)hydrazine by density functional method

    Science.gov (United States)

    Subramanian, N.; Sundaraganesan, N.; Jayabharathi, J.

    2010-07-01

    Quantum chemical calculations of energies, geometrical structure and vibrational wavenumbers of 1,2-bis(3-methoxy-4-hydroxybenzylidene)hydrazine [vanillin azine (VA)] were carried out by using density functional (DFT/B3LYP) method with 6-31G(d) as basis set. The optimized geometrical parameters obtained by DFT calculations are in good agreement with single crystal XRD data. The vibrational spectral data obtained from solid phase FT-IR and FT-Raman spectra are assigned based on the results of the theoretical calculations. The observed spectra are found to be in good agreement with calculated values. The electric dipole moment ( μ) and the first hyperpolarizability ( β) values of the investigated molecule have been computed using ab initio quantum mechanical calculations. The calculation results also show that the VA molecule might have microscopic nonlinear optical (NLO) behavior with non-zero values. A detailed interpretation of the infrared and Raman spectra of VA was also reported. The energy and oscillator strength calculated by time-dependent density functional theory (TD-DFT) results complements with the experimental findings. The calculated HOMO and LUMO energies show that charge transfer occurs within the molecule. The theoretical NMR chemical shifts complement with experimentally measured ones.

  5. Synthesis, X-ray crystallography, spectroscopic (FT-IR, 1H &13C NMR and UV), computational (DFT/B3LYP) and enzymes inhibitory studies of 7-hydroximinocholest-5-en-3-ol acetate

    Science.gov (United States)

    Ahmad, Faheem; Parveen, Mehtab; Alam, Mahboob; Azaz, Shaista; Malla, Ali Mohammed; Alam, Mohammad Jane; Lee, Dong-Ung; Ahmad, Shabbir

    2016-07-01

    The present study reports the synthesis of 7-Hydroximinocholest-5-en-3-ol acetate (syn. 3β-acetoxycholest-5-en-7-one oxime; in general, steroidal oxime). The identity of steroidal molecule was confirmed by NMR, FT-IR, MS, CHN microanalysis and X-ray crystallography. DFT calculations on the titled molecule have been performed. The molecular structure and spectra interpreted by Gaussian hybrid computational analysis theory (B3LYP) are found to be in good correlation with the experimental data obtained from the various spectrophotometric techniques. The vibrational bands appearing in the FTIR are assigned with great accuracy using harmonic frequencies along with intensities and animated modes. Molecular properties like HOMO-LUMO analysis, chemical reactivity descriptors, MEP mapping, dipole moment and natural atomic charges have been presented at the same level of theory. Moreover, the Hirshfeld analysis was carried out to ascertain the secondary interactions and associated 2D fingerprint plots. The percentages of various interactions are pictorialized by fingerprint plots of Hirshfeld surface. Steroidal oxime exhibited promising inhibitory activity against acetylcholinesterase (AChE) as compared to the reference drug, tacrine. Molecular docking was performed to introduce steroidal molecules into the X-ray crystal structures of acetylcholinesterase at the active site to find out the probable binding mode. The results of molecular docking admitted that steroidal oxime may exhibit enzyme inhibitor activity.

  6. Spectroscopic studies (FT-IR, FT-Raman, UV-Visible), normal co-ordinate analysis, first-order hyperpolarizability and HOMO, LUMO studies of 3,4-dichlorobenzophenone by using Density Functional Methods.

    Science.gov (United States)

    Venkata Prasad, K; Samatha, K; Jagadeeswara Rao, D; Santhamma, C; Muthu, S; Mark Heron, B

    2015-01-01

    The vibrational frequencies of 3,4-dichlorobenzophenone (DCLBP) were obtained from the FT-IR and Raman spectral data, and evaluated based on the Density Functional Theory using the standard method B3LYP with 6-311+G(d,p) as the basis set. On the basis of potential energy distribution together with the normal-co-ordinate analysis and following the scaled quantum mechanical force methodology, the assignments for the various frequencies were described. The values of the electric dipole moment (μ) and the first-order hyperpolarizability (β) of the molecule were computed. The UV-absorption spectrum was also recorded to study the electronic transitions. The calculated HOMO and LUMO energies show that charge transfer occurs within the molecule. The NBO analysis, to study the intramolecular hyperconjugative interactions, was carried out. Mulliken's net charges were evaluated. The MEP and thermodynamic properties were also calculated. The electron density-based local reactivity descriptor, such as Fukui functions, was calculated to explain the chemical selectivity or reactivity site in 3,4-dichlorobenzophenone. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Spectroscopic (FT-IR, FT-Raman, and UV-visible) and quantum chemical studies on molecular geometry, Frontier molecular orbitals, NBO, NLO and thermodynamic properties of 1-acetylindole.

    Science.gov (United States)

    Shukla, Vikas K; Al-Abdullah, Ebtehal S; El-Emam, Ali A; Sachan, Alok K; Pathak, Shilendra K; Kumar, Amarendra; Prasad, Onkar; Bishnoi, Abha; Sinha, Leena

    2014-12-10

    Quantum chemical calculations of ground state energy, geometrical structure and vibrational wavenumbers of 1-acetylindole were carried out using density functional (DFT/B3LYP) method with 6-311++G(d,p) basis set. The FT-IR and FT-Raman spectra were recorded in the condensed state. The fundamental vibrational wavenumbers were calculated and a good correlation between experimental and scaled calculated wavenumbers has been accomplished. Electric dipole moment, polarizability and first static hyperpolarizability values of 1-acetylindole have been calculated at the same level of theory and basis set. The results show that the 1-acetylindole molecule possesses nonlinear optical (NLO) behavior with non-zero values. Stability of the molecule arising from hyper-conjugative interactions and charge delocalization has been analyzed using natural bond orbital (NBO) analysis. UV-Visible spectrum of the molecule was recorded in the region 200-500nm and the electronic properties like HOMO and LUMO energies and composition were obtained using TD-DFT method. The calculated energies and oscillator strengths are in good correspondence with the experimental data. The thermodynamic properties of the compound under investigation were calculated at different temperatures. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Synthesis, spectroscopic investigations (FT-IR, NMR, UV-Vis, and TD-DFT), and molecular docking of (E)-1-(benzo[d][1, 3]dioxol-6-yl)-3-(6-methoxynaphthalen-2-yl)prop-2-en-1-one

    Science.gov (United States)

    Therasa Alphonsa, A.; Loganathan, C.; Athavan Alias Anand, S.; Kabilan, S.

    2017-02-01

    The compound (E)-1-(benzo [d] [1, 3] dioxol-6-yl)-3-(6-methoxy naphthalen-2-yl) prop-2-en-1-one (AKN) was synthesized and characterized by FT-IR, NMR, and UV-Vis spectrometer. The optimized molecular geometry, bond lengths, bond angles, atomic charges, harmonic vibrational wave numbers and intensities of vibrational bonds of the title compound have been investigated by Time dependent- Density Functional Theory (TD-DFT) using a standard B3LYP method with 6-31 G (d, p) basis set available in the Gaussian 09W package. 1H and 13C NMR chemical shifts of the molecule were calculated using Gauge-independent atomic orbital method (GIAO). Experimental excitation energies of the molecules were matched with the theoretically calculated energies. The atomic charge distributions of the various atoms present in the AKN were obtained by Mulliken charge population analysis. The Molecular Electrostatic Potential (MEP) analysis reveals the sites for electrophilic attack and nucleophilic reactions in the molecule. The difference between the observed and scaled frequencies was small. The HOMO to LUMO transition implies an electron density transfer. The intramolecular contacts have been interpreted using Natural Bond Orbital (NBO) analysis. The calculation results were applied to simulate spectra of the title compound, which show excellent agreement with observed spectra. To provide information about the interactions between human cytochrome protein and the novel compound theoretically, docking studies were carried out using Schrödinger software.

  9. FT-IR study on interactions between medroxyprogesterone acetate and solvent in CHCl3/cyclo-C6H12 and CCl4/cyclo-C6H12 binary solvent systems

    Science.gov (United States)

    Shi, Jie-hua; Fan, Chun-hui

    2012-09-01

    The intermolecular interactions between medroxyprogesterone acetate (MPA) and CHCl3 and CCl4 solvent in CHCl3/cyclo-C6H12 and CCl4/cyclo-C6H12 binary solvent systems have been studied by Fourier transform infrared spectroscopy (FT-IR). The experimental results showed that there are hydrogen bonding interactions between oxygen atoms of all carbonyl groups in MPA and hydrogen atom of CHCl3 so as to form 1:3 complex of MPA with CHCl3 and produce three new absorption bands at 1728.9-1736.1, 1712.7-1717.4 and 1661.9-1673.8 cm-1, respectively. And, 1:1 complex of MPA with CCl4 is formed in CCl4/cyclo-C6H12 binary solvent as a result of hydrogen bonding interaction between C3 carbonyl group and empty d-orbital in chlorine atom of CCl4 leading to producing new absorption band at 1673.2-1674.2 cm-1. However, all free carbonyl and associated carbonyl stretching vibrations of MPA in CHCl3/cyclo-C6H12 and CCl4/cyclo-C6H12 binary solvent systems shift to lower wavenumbers with the increasing of volume fraction of CHCl3 and CCl4 in binary solvent systems owing to the dipole-dipole interaction and the dipole-induced dipole interaction between MPA and solvents.

  10. FT-IR, FT-Raman and NMR characterization of 2-isopropyl-5-methylcyclohexyl quinoline-2-carboxylate and investigation of its reactive and optoelectronic properties by molecular dynamics simulations and DFT calculations

    Science.gov (United States)

    Menon, Vidya V.; Fazal, Edakot; Mary, Y. Sheena; Panicker, C. Yohannan; Armaković, Stevan; Armaković, Sanja J.; Nagarajan, Subban; Van Alsenoy, C.

    2017-01-01

    The FT-IR and FT-Raman spectra of the synthesized compound, 2-isopropyl-5-methylcyclohexyl quinoline-2-carboxylate is recorded and analyzed. Optimized molecular structure, wave numbers, corresponding assignments regarding 2-isopropyl-5-methylcyclohexyl quinoline-2-carboxylate has become screened tentatively as well as hypothetically using Gaussian09 program package. Natural bonding orbital assessment has been completed with a reason to clarify charge transfer or conjugative interaction, the intra-molecular re-hybridization and delocalization of electron density within the molecule. The NMR spectral assessment had been made choosing structure property relationship by chemical shifts along with the magnetic shielding effects regarding the title compound. The first and second hyperpolarizabilities were calculated. The calculated first order hyperpolarizability is commensurate with the documented worth of very similar derivatives and could be an interesting object for more experiments on nonlinear optics. Local reactivity properties have been investigated using average local ionization energies and Fukui functions. Investigation of optoelectronic properties encompassed calculations of reorganization energies and hopping rates of charge carriers within the framework of Marcus semi-empiric approach. The docked ligand title compound forms a stable complex with CDK inhibitors and gives a binding affinity value of -9.7 kcal/mol and molecular docking results suggest that the compound might exhibit inhibitory activity against CDK inhibitors.

  11. Spectroscopic (FT-IR, FT-Raman, 1H- and 13C-NMR, Theoretical and Microbiological Study of trans o-Coumaric Acid and Alkali Metal o-Coumarates

    Directory of Open Access Journals (Sweden)

    Małgorzata Kowczyk-Sadowy

    2015-02-01

    Full Text Available This work is a continuation of research on a correlation between the molecular structure and electronic charge distribution of phenolic compounds and their biological activity. The influence of lithium, sodium, potassium, rubidium and cesium cations on the electronic system of trans o-coumaric (2-hydroxy-cinnamic acid was studied. We investigated the relationship between the molecular structure of the tested compounds and their antimicrobial activity. Complementary molecular spectroscopic techniques such as infrared (FT-IR, Raman (FT-Raman, ultraviolet-visible (UV-VIS and nuclear magnetic resonance (1H- and 13C-NMR were applied. Structures of the molecules were optimized and their structural characteristics were calculated by the density functional theory (DFT using the B3LYP method with 6-311++G** as a basis set. Geometric and magnetic aromaticity indices, atomic charges, dipole moments and energies were also calculated. Theoretical parameters were compared to the experimental characteristics of investigated compounds. Correlations between certain vibrational bands and some metal parameters, such as electronegativity, ionization energy, atomic and ionic radius, were found. The microbial activity of studied compounds was tested against Escherichia coli, Bacillus subtilis, Pseudomonas aeruginosa, Staphylococcus aureus, Proteus vulgaris and Candida albicans.

  12. Infrared spectra of U.S. automobile original finishes (post - 1989). VIII: In situ identification of bismuth vanadate using extended range FT-IR spectroscopy, Raman spectroscopy, and X-ray fluorescence spectrometry.

    Science.gov (United States)

    Suzuki, Edward M

    2014-03-01

    Chrome Yellow (PbCrO4 ·xPbSO4 ) was a common pigment in U.S. automobile OEM finishes for more than three decades, but in the early 1990s its use was discontinued. One of its main replacements was Bismuth Vanadate (BiVO4 ·nBi2 MoO6 , n = 0-2), which was commercially introduced in 1985, as this inorganic pigment also produces a very bright hue and has excellent outdoor durability. This paper describes the in situ identification of Bismuth Vanadate in automotive finishes using FT-IR and dispersive Raman spectroscopy and XRF spectrometry. Some differentiation of commercial formulations of this pigment is possible based on far-infrared absorptions, Raman data, and elemental analysis. The spectral differences arise from the presence or absence of molybdenum, the use of two crystal polymorphs of BiVO4 , and differences in pigment stabilizers. Bismuth Vanadate is usually not used alone, and it is typically found with Isoindoline Yellow, hydrous ferric oxide, rutile, Isoindolinone Yellow 3R, or various combinations of these.

  13. FT-IR, HOMO-LUMO, NBO, MEP analysis and molecular docking study of 3-Methyl-4-{(E)-[4-(methylsulfanyl)-benzylidene]amino}1H-1,2,4-triazole-5(4H)-thione.

    Science.gov (United States)

    Panicker, C Yohannan; Varghese, Hema Tresa; Manjula, P S; Sarojini, B K; Narayana, B; War, Javeed Ahamad; Srivastava, S K; Van Alsenoy, C; Al-Saadi, Abdulaziz A

    2015-01-01

    FT-IR spectrum of 3-Methyl-4-{(E)-[4-(methylsulfanyl)-benzylidene]amino}1H-1,2,4-triazole-5(4H)-thione was recorded and analysed. The vibrational wavenumbers were computed and at HF and DFT levels of theory. The data obtained from wavenumber calculations are used to assign the vibrational bands obtained in the IR spectrum. The NH stretching wavenumber is red shifted in the IR spectrum from the computed value, which indicates the weakening of the NH bond. The geometrical parameters of the title compound are in agreement with the XRD results. NBO analysis, HOMO-LUMO, first and second order hyperpolarizability and molecular electrostatic potential results are also reported. From the MEP map it is evident that the negative regions are localized over the sulphur atoms and N3 atom of triazole ring and the maximum positive region is localized on NH group, indicating a possible site for nucleophilic attack. Prediction of Activity Spectra analysis of the title compound predicts anti-tuberculostic activity with probability to be active value of 0.543. Molecular docking studies reveal that the triazole nitrogen atoms and the thione sulphur atom play vital role in bonding and results draw us to the conclusion that the compound might exhibit anti-tuberculostic activity.

  14. Synthesis, UV/vis, FT-IR and Mössbauer spectroscopic characterization and molecular structure of the Bis[4-(2-aminoethyl)morpholine](tetrakis(4-metoxyphenyl)porphyrinato) iron(II) complex

    Science.gov (United States)

    Ben Haj Hassen, Leila; Ezzayani, Khaireddine; Rousselin, Yoann; Stern, Christine; Nasri, Habib; Schulz, Charles E.

    2016-04-01

    The synthesis, the UV-visible, FT-IR and Mössbauer spectroscopy and the crystal structure characterizations of the bis[4-(2-Aminoethyl)morpholine]tetrakis(4-metoxyphenyl)porphy-rinato)iron(II) complex are described. The title compound crystallizes in the triclinic, space group P-1, with a = 11.1253(4) Å, b = 11.2379(4) Å, c = 11.5488(4) Å, α = 72.304(2)°, β = 86.002(2)°, γ = 72.066(2)°, V = 1308.28(8) Å3, Z = 1. The Môssbauer data are consistent with an iron(II) low-spin (S = 0) porphyin species. The spin-state is confirmed by the value of the average equatorial iron-nitrogen pyrrole distance (Fe__Np = 1.988(2) Å) which is in the normal range of low-spin iron(II) porphyrins. The supramolecular architecture involve hydrogen bonding including C__H … O and weak C__H … Cg π intermolecular interactions involving centroides (Cg) pyrrole and phenyl rings.

  15. Theoretical study on molecular structure and vibrational analysis included FT-IR, FT-Raman and UV techniques of 2,4,5-trimethylbenzoic acid (monomer and dimer structures)

    Science.gov (United States)

    Karabacak, Mehmet; Bilgili, Sibel; Atac, Ahmet

    2015-01-01

    Theoretical study on the structural and vibrational analysis of monomer and dimer structures of 2,4,5-trimethylbenzoic acid (2,4,5-TMBA, C10H12O2) were presented. The geometry of the molecule was fully optimized. The Fourier transform infrared (FT-IR) and the Fourier transform Raman (FT-Raman) spectra of the title molecule in solid phase were recorded in the region 4000-400 cm-1 and 4000-50 cm-1, respectively. The geometrical parameters and energies were investigated with the help of Density Functional Theory (DFT) employing B3LYP method and 6-311++G(d,p) basis set. The spectroscopic data of the molecule in the ground state were calculated by using DFT/B3LYP method with the 6-311++G(d,p) basis set. The vibrational spectra were calculated and fundamental vibrations were assigned on the basis of the potential energy distribution (PED) of the vibrational modes. The geometric parameters were compared with experimental data of the title molecule. The UV absorption spectrum of the studied compound was computed and recorded in the range of 190-400 nm dissolved in water and ethanol. Besides, charge transfer occurring in the molecule between HOMO and LUMO energies, frontier energy gap, molecular electrostatic potential (MEP) were calculated and presented. In addition these, thermodynamic properties and Mulliken atomic charges were performed.

  16. Conformational stability, vibrational spectra, HOMO-LUMO and NBO analysis of 1,3,4-thiadiazolidine-2,5-dithione with experimental (FT-IR and FT-Raman) techniques and scaled quantum mechanical calculations.

    Science.gov (United States)

    Xavier, R John; Dinesh, P

    2013-09-01

    The experimental and theoretical study on the structure and vibrations of 1,3,4-thiadiazolidine-2,5-dithione (TDZD) is presented. The FT-IR spectra (4000-400 cm(-1)) and the FT-Raman spectra (4000-50 cm(-1)) of the title molecule have been recorded. The energies of TDZD were obtained for all the possible four conformers from HF and DFT with 6-311G(d,p) and 6-311++G(d,p) basis set calculations. From the computational results, conformer C4 is identified as the most stable conformers of TDZD. The spectroscopic and theoretical results are compared with the corresponding properties for TDZD of C4 conformer. The temperature dependence of thermodynamic properties has been analyzed. Molecular stability and bond strength were investigated by applying the natural bond orbital analysis (NBO). The calculated HOMO and LUMO energies show that charge transfer occurs in the molecules. Information about the size, shape, charge density distribution, and site of chemical reactivity of the molecules has been obtained by mapping electron density isosurface with electrostatic potential (ESP). The dipole moment (λ) and polarizability (α), anisotropy polarizability (Δα) and first hyperpolarizability (βtotal) of the molecule have been reported.

  17. FT-Raman, FT-IR, UV spectroscopic, NBO and DFT quantum chemical study on the molecular structure, vibrational and electronic transitions of clopidogrel hydrogen sulfate form 1: a comparison to form 2.

    Science.gov (United States)

    Srivastava, Anubha; Mishra, Rashmi; Tandon, Poonam; Bansal, A K

    2013-03-01

    Clopidogrel hydrogen sulfate (+)-(S)-(2-chlorophenyl)-6,7-dihydrothieno[3,2-c]pyridine-5(4H)-acetate sulfate (1:1), is a selective adenosine diphosphate (ADP) receptor antagonist often used in the treatment of coronary artery, peripheral vascular and cerebrovascular diseases. In the present communication, a comparative study of two polymorphic forms (forms 1 and 2) of clopidogrel hydrogen sulfate (CLP) has been reported. There is difference in conformation and intermolecular hydrogen bonding pattern of two forms. These differences are nicely reflected in the vibrational spectra. The molecular structure, fundamental vibrational frequencies and intensity of the vibrational bands of CLP form 1 are interpreted with the aid of structure optimizations and normal mode analysis based on ab initio HF and DFT method employing 6-311++G(d,p) basis. Polymorphism in CLP have been studied using various characterization tools like FT-Raman, FT-IR spectroscopy and DSC in combination with the quantum chemical calculations. UV-vis spectroscopic studies along with HOMO-LUMO analysis of both polymorphs were performed. The solvent effect calculated by TD-DFT/IEF-PCM/6-31G model results complements with the experimental findings. Stability of the molecule arising from hyper conjugative interactions and charge delocalization has been analyzed using natural bond orbital (NBO) analysis.

  18. FT-IR, molecular structure, HOMO-LUMO, MEP, NBO analysis and first order hyperpolarizability of Methyl 4,4″-difluoro-5";-methoxy-1,1";:3";,1″-terphenyl-4";-carboxylate

    Science.gov (United States)

    Sheena Mary, Y.; Yohannan Panicker, C.; Narayana, B.; Samshuddin, S.; Sarojini, B. K.; Van Alsenoy, C.

    2014-12-01

    Methyl 4,4″-difluoro-5";-methoxy-1,1";:3";,1″-terphenyl-4";-carboxylate was prepared by the aromatization of a cyclohexenone derivative, Methyl 4,6-bis(4-fluorophenyl)-2-oxocyclohex-3-ene-1-carboxylate using iodine and methanol at reflux conditions. The structure of the compound was confirmed by IR and single crystal X-ray diffraction studies. FT-IR spectrum was recorded and analyzed. The crystal structure is also described. The vibrational wavenumbers are calculated using HF and DFT methods and are assigned with the help of potential energy distribution. The geometrical parameters of the title compound obtained from XRD studies are in agreement with the calculated (DFT) values. The stability of the molecule arising from hyper-conjugative interaction and charge delocalization has been analyzed using NBO analysis. According to the MEP analysis, negative region (red) is mainly over the carbonyl group showing large activity. The calculated hyperpolarizability of the title compound is greater than that of the standard NLO material urea and the title compound is an attractive object for future studies of nonlinear optical properties.

  19. Spectroscopic (FT-IR, FT-Raman, UV, 1H and 13C NMR) profiling and computational studies on methyl 5-methoxy-1H-indole-2-carboxylate: A potential precursor to biologically active molecules

    Science.gov (United States)

    Almutairi, Maha S.; Xavier, S.; Sathish, M.; Ghabbour, Hazem A.; Sebastian, S.; Periandy, S.; Al-Wabli, Reem I.; Attia, Mohamed I.

    2017-04-01

    Methyl 5-methoxy-1H-indole-2-carboxylate (MMIC) was prepared via esterification of commercially available 5-methoxyindole-2-carboxylic acid. The title molecule MMIC was characterised using FT-IR and FT-Raman in the ranges of 4000-500 and 4000-50 cm-1, respectively. The fundamental modes of the vibrations were assigned and the UV-visible spectrum of the MMIC molecule was recorded in the range of 200-400 nm to explore its electronic nature. The HOMO-LUMO energy distribution was calculated and the bonding and anti-bonding structures of the title molecule were studied and analysed using the natural bond orbital (NBO) approach. The reactivity of the MMIC molecule was also investigated and both the positive and negative centres of the molecule were identified using chemical descriptors and molecular electrostatic potential (MEP) analysis. The chemical shifts of the 1H and 13C NMR spectra were noted and the magnetic field environment of the MMIC molecule are discussed. The non-linear optical (NLO) properties of the title molecule were studied based on its calculated values of polarisability and hyperpolarisability. All computations were obtained by DFT methods using the 6-311++G (d,p) basis set.

  20. FT-Raman, FT-IR, UV spectroscopic, NBO and DFT quantum chemical study on the molecular structure, vibrational and electronic transitions of clopidogrel hydrogen sulfate form 1: A comparison to form 2

    Science.gov (United States)

    Srivastava, Anubha; Mishra, Rashmi; Tandon, Poonam; Bansal, A. K.

    2013-03-01

    Clopidogrel hydrogen sulfate (+)-(S)-(2-chlorophenyl)-6,7-dihydrothieno[3,2-c]pyridine-5(4H)-acetate sulfate (1:1), is a selective adenosine diphosphate (ADP) receptor antagonist often used in the treatment of coronary artery, peripheral vascular and cerebrovascular diseases. In the present communication, a comparative study of two polymorphic forms (forms 1 and 2) of clopidogrel hydrogen sulfate (CLP) has been reported. There is difference in conformation and intermolecular hydrogen bonding pattern of two forms. These differences are nicely reflected in the vibrational spectra. The molecular structure, fundamental vibrational frequencies and intensity of the vibrational bands of CLP form 1 are interpreted with the aid of structure optimizations and normal mode analysis based on ab initio HF and DFT method employing 6-311++G(d,p) basis. Polymorphism in CLP have been studied using various characterization tools like FT-Raman, FT-IR spectroscopy and DSC in combination with the quantum chemical calculations. UV-vis spectroscopic studies along with HOMO-LUMO analysis of both polymorphs were performed. The solvent effect calculated by TD-DFT/IEF-PCM/6-31G model results complements with the experimental findings. Stability of the molecule arising from hyper conjugative interactions and charge delocalization has been analyzed using natural bond orbital (NBO) analysis.

  1. Synthesis, spectroscopic (FT-IR, FT-Raman, NMR, UV-Visible), Fukui function, antimicrobial and molecular docking study of (E)-1-(3-bromobenzylidene)semicarbazide by DFT method

    Science.gov (United States)

    Raja, M.; Raj Muhamed, R.; Muthu, S.; Suresh, M.; Muthu, K.

    2017-02-01

    The title compound, (E)-1-(3-bromobenzylidene)semicarbazide (3BSC) was synthesized and characterized by FT-IR, FT-Raman, UV, 1HNMR and 13CNMR spectral analysis. The optimized molecular geometry, the vibrational wavenumbers, the infrared intensities and the Raman scattering activities were calculated by using density functional theory (DFT) B3LYP method with 6-311++G(d,p) basis set. The calculated HOMO and LUMO energies show that charge transfer within the molecule. Stability of the molecule arising from hyperconjugative interactions, charge delocalization have been analyzed using natural bond orbital analysis (NBO). The hyperpolarizability calculation reveals the present material has a reasonably good propensity for nonlinear optical activity. Molecular electrostatic potential (MEP) and Fukui functions were also performed. The thermodynamic properties (heat capacity, entropy, and enthalpy) of the 3BSC at different temperatures have been calculated. The biological applications of 3BSC have been screened for its antimicrobial activity and found to exhibit antifungal and antibacterial effects. In addition, the Molecular docking was also performed for the different receptors.

  2. Molecular structure, spectroscopic (FT-IR, FT Raman, UV, NMR and THz) investigation and hyperpolarizability studies of 3-(2-Chloro-6-fluorophenyl)-1-(2-thienyl) prop-2-en-1-one

    Science.gov (United States)

    Kumar, Rajesh; Kumar, Amit; Deval, Vipin; Gupta, Archana; Tandon, Poonam; Patil, P. S.; Deshmukh, Prathmesh; Chaturvedi, Deepika; Watve, J. G.

    2017-02-01

    In the present work, a combined experimental and theoretical study on ground state molecular structure, spectroscopic and nonlinear optical properties of the chalcone derivative 3-(2-Chloro-6-fluorophenyl)-1-(2-thienyl) prop-2-en-1-one (2C6F2SC) is reported. Initial geometry generated from single crystal X-ray diffraction parameters was minimized at DFT level employing B3LYP/6-311++G (d,p) without any constraint to the potential energy surface. The molecule has been characterized using various experimental techniques FT-IR, FT-Raman, UV-Vis, 1H NMR, TD-THz and the spectroscopic data have been analyzed theoretically by Density Functional Theory (DFT) method. Harmonic vibrational frequencies were calculated theoretically using the optimized ground state geometry and the spectra were interpreted by means of potential energy distribution. Time Dependent Density Functional Theory (TD-DFT) has been used to calculate energies, absorption wavelengths, oscillator strengths of electronic singlet-singlet transitions. The calculated energy and oscillator strength complement with the experimental findings. The HOMO-LUMO energy gap explains the charge interaction taking place within the molecule. Good correlations between the experimental 1H NMR chemical shifts and calculated GIAO shielding tensors were found. Stability of the molecule, hyperconjugative interactions and charge delocalization has been analyzed by natural bond orbital (NBO) analysis. The first order hyperpolarizability (β) of this molecular system and related properties (μ, and Δα) have been calculated using the finite-field approach.

  3. Molecular structure, vibrational spectroscopic (FT-IR, FT-Raman), UV-vis spectra, first order hyperpolarizability, NBO analysis, HOMO and LUMO analysis, thermodynamic properties of benzophenone 2,4-dicarboxylic acid by ab initio HF and density functional method.

    Science.gov (United States)

    Chaitanya, K

    2012-02-01

    The FT-IR (4000-450 cm(-1)) and FT-Raman spectra (3500-100 cm(-1)) of benzophenone 2,4-dicarboxylic acid (2,4-BDA) have been recorded in the condensed state. Density functional theory calculation with B3LYP/6-31G(d,p) basis set have been used to determine ground state molecular geometries (bond lengths and bond angles), harmonic vibrational frequencies, infrared intensities, Raman activities and bonding features of the title compounds. The assignments of the vibrational spectra have been carried out with the help of normal co-ordinate analysis (NCA) following the scaled quantum mechanical force field (SQMFF) methodology. The first order hyperpolarizability (β0) and related properties (β, α0 and Δα) of 2,4-BDA is calculated using HF/6-31G(d,p) method on the finite-field approach. The stability of molecule has been analyzed by using NBO analysis. The calculated first hyperpolarizability shows that the molecule is an attractive molecule for future applications in non-linear optics. The calculated HOMO and LUMO energies show that charge transfer occurs within these molecules. Mulliken population analysis on atomic charges is also calculated. Because of vibrational analyses, the thermodynamic properties of the title compound at different temperatures have been calculated. Finally, the UV-vis spectra and electronic absorption properties were explained and illustrated from the frontier molecular orbitals.

  4. Structural, vibrational (FT-IR and FT-Raman) and UV-Vis spectral analysis of 1-phenyl-3-(1,2,3-thiadiazol-5-yl)urea by DFT method.

    Science.gov (United States)

    Meganathan, C; Sebastian, S; Sivanesan, I; Lee, Keun Woo; Jeong, Byoung Ryong; Oturak, Halil; Sudha, S; Sundaraganesan, N

    2012-09-01

    The Fourier Transform Infrared (FT-IR) and FT-Raman spectra of 1-phenyl-3-(1,2,3-thiadiazol-5-yl)urea (TDZ) have been recorded and analyzed. The molecular structure and vibrational spectra (harmonic and anharmonic) of TDZ were calculated by the Density Functional Theory (DFT) method using the B3LYP function with 6-31G(d,p) as the basis set. A detailed interpretation of the Infrared and Raman spectra of TDZ was reported based on Potential Energy Distribution (PED). The first order hyperpolarizability (β(0)) of this novel molecular system and related properties (β, α(0) and Δα) were calculated using HF/6-31G(d,p) method on the finite-field approach. Stability of the molecule arising from hyperconjugative interactions and charge delocalization have been analyzed using Natural Bond Orbital analysis. The results show that charge in electron density in the σ(∗) and π(∗) antibonding orbitals and second order delocalization energies E(2) confirm the occurrence of Intramolecular Charge Transfer (ICT) within the molecule. UV-Vis spectrum of the title molecule was recorded and the electronic properties such as HOMO and LUMO energies were determined by Time-Dependent Density Functional Theory approach.

  5. Synthesis, spectroscopic (FT-IR, FT-Raman, NMR, UV-Visible), NLO, NBO, HOMO-LUMO, Fukui function and molecular docking study of (E)-1-(5-bromo-2-hydroxybenzylidene)semicarbazide

    Science.gov (United States)

    Raja, M.; Raj Muhamed, R.; Muthu, S.; Suresh, M.

    2017-08-01

    The title compound, (E)-1-(5-bromo-2-hydroxybenzylidene)semicarbazide (15BHS) was synthesized and characterized by FT-IR, FT-Raman, UV, 1HNMR and 13CNMR spectral analysis. The optimized molecular geometry, the vibrational wavenumbers, the infrared intensities and the Raman scattering activities were calculated by using density functional theory(DFT) B3LYP method with 6-311++G(d,p) basis set. The detailed interpretation of the vibrational spectra has been carried out by VEDA program. The calculated HOMO and LUMO energies show that charge transfer within the molecule. Stability of the molecule arising from hyperconjugative interactions, charge delocalization have been analyzed using natural bond orbital analysis (NBO). The first order hyperpolarizability, Molecular electrostatic potential (MEP) and Fukui functions were also performed. To study the biological activity of the investigation molecule, molecular docking was done to identify the hydrogen bond lengths and binding energy with different antifungal proteins. The thermodynamic properties (heat capacity, entropy, and enthalpy) of the 15BHS at different temperatures have been calculated.

  6. Analytical study of canvas painting collection from the Basilica de la Virgen de los Desamparados using SEM/EDX, FT-IR, GC and electrochemical techniques.

    Science.gov (United States)

    Doménech-Carbó, M T; Casas-Catalán, M J; Doménech-Carbó, A; Mateo-Castro, R; Gimeno-Adelantado, J V; Bosch-Reig, F

    2001-04-01

    A new method, based on the combined use of scanning electron microscopy-x-ray microanalysis, Fourier transform infrared spectroscopy, gas chromatography and differential pulse voltammetry, is proposed which permits a parallel investigation of organic and inorganic materials and the characterization of the artistic technique employed in canvas painting. The proposed method has led to analyze succesfully the canvas painting collection exhibited in the Basílica de la Virgen de los Desamparados (Valencia, Spain) which includes art works from 17th to 20th century.

  7. Molecular structure (monomeric and dimeric) and hydrogen bonds in 5-benzyl 2-thiohydantoin studied by FT-IR and FT-Raman spectroscopy and DFT calculations.

    Science.gov (United States)

    Deval, Vipin; Kumar, Amit; Gupta, Vineet; Sharma, Anamika; Gupta, Archana; Tandon, Poonam; Kunimoto, Ko-Ki

    2014-11-11

    In the present work the structural and spectral characteristics of 5-benzyl-2-thiohydantoin (5-BTH) have been studied by methods of infrared, Raman spectroscopy and quantum chemistry. Electrostatic potential surface, optimized geometry, harmonic vibrational frequencies, infrared intensities and activities of Raman scattering were calculated by density functional theory (DFT) employing B3LYP with complete relaxation in the potential energy surface using 6-311G++(d,p) basis set. Our results support the hydrogen bonding pattern proposed by reported crystalline structure. Stability of the molecule arising from hyperconjugative interactions, charge delocalization have been analyzed using natural bond orbital (NBO) analysis. The 13C nuclear magnetic resonance (NMR) chemical shifts of the molecule are calculated by the gauge independent atomic orbital (GIAO) method and compared with experimental results. UV-vis spectrum of the compound was recorded in methanol solvent. The TD-DFT calculations have been performed to explore the influence of electronic absorption spectra in the gas phase, as well as in solution environment using PCM and 6-311++G(d,p) basis set. In addition, the thermodynamic properties of the compound were calculated at different temperatures and corresponding relations between the properties and temperature were also studied.

  8. In situ FT-IR and UV-vis spectroscopy of the low-temperature NO disproportionation mediated by solid state manganese(II) porphyrinates.

    Science.gov (United States)

    Martirosyan, Garik G; Azizyan, Arsen S; Kurtikyan, Tigran S; Ford, Peter C

    2006-05-15

    The heterogeneous reaction between NO gas and sublimed layers of manganese(II) porphyrinato complexes Mn(Por) (Por = TPP (tetraphenylporphyrinato dianion), TMP (tetramesitylporphyrinato dianion), or TPP(d20) (perdeuterated tetraphenylporphyrinato dianion)) has been monitored by IR and optical spectroscopy over the temperature range of 77 K to room temperature. These manganese porphyrins promote NO disproportionation to NO2 species and N2O, and the reaction proceeds via several distinct stages. At 90 K, the principal species observed spectrally are the nitric oxide dimer, cis-ONNO, two manganese nitrosyls, the simple NO adduct Mn(Por)(NO), and another intermediate (1) that is apparently critical to the disproportionation mechanism. This key intermediate is formed prior to N2O evolution, and proposals regarding its likely structure are offered. When the system is warmed to 130 K, the disproportionation products, N2O and the O-coordinated nitrito complex Mn(Por)(NO)(ONO) (2), are formed. IR spectral changes show that, upon further warming to 200 K, 2 isomerizes into the N-bonded nitro linkage isomer Mn(Por)(NO)(NO2) (3). After it is warmed to room temperature, the latter species loses NO and converts to the known 5-coordinate nitrito complex Mn(Por)(ONO) (4).

  9. Catalytic behavior of metal catalysts in high-temperature RWGS reaction: In-situ FT-IR experiments and first-principles calculations

    Science.gov (United States)

    Choi, Sungjun; Sang, Byoung-In; Hong, Jongsup; Yoon, Kyung Joong; Son, Ji-Won; Lee, Jong-Ho; Kim, Byung-Kook; Kim, Hyoungchul

    2017-01-01

    High-temperature chemical reactions are ubiquitous in (electro) chemical applications designed to meet the growing demands of environmental and energy protection. However, the fundamental understanding and optimization of such reactions are great challenges because they are hampered by the spontaneous, dynamic, and high-temperature conditions. Here, we investigated the roles of metal catalysts (Pd, Ni, Cu, and Ag) in the high-temperature reverse water-gas shift (RWGS) reaction using in-situ surface analyses and density functional theory (DFT) calculations. Catalysts were prepared by the deposition-precipitation method with urea hydrolysis and freeze-drying. Most metals show a maximum catalytic activity during the RWGS reaction (reaching the thermodynamic conversion limit) with formate groups as an intermediate adsorbed species, while Ag metal has limited activity with the carbonate species on its surface. According to DFT calculations, such carbonate groups result from the suppressed dissociation and adsorption of hydrogen on the Ag surface, which is in good agreement with the experimental RWGS results.

  10. Structure–acidity correlation of supported tungsten(VI)-oxo-species: FT-IR and TPD studies of adsorbed pyridine and catalytic decomposition of 2-propanol

    Energy Technology Data Exchange (ETDEWEB)

    Zaki, M.I., E-mail: mizaki@mu.edu.eg; Mekhemer, G.A.H.; Fouad, N.E.; Rabee, A.I.M.

    2014-07-01

    The amount of 10 wt%-WO{sub 3} was supported on alumina, titania or silica by impregnation with aqueous solution of ammonium paratungstate and subsequent calcination at 500 °C for 10 h. Tungstate-related chemical and physical changes in the calcination products were resolved by ex-situ infrared (IR) spectroscopy. Nature of exposed surface acid sites were probed by in-situ IR spectroscopy of adsorbed pyridine (Py) molecules at room temperature (RT). The relative strength of the acid sites thus probed was gauged by combining results of temperature-programmed desorption (TPD) measurements of the RT-adsorbed Py with those communicated by in-situ IR spectra of residual Py on the surface after a brief thermoevacuation at high temperatures (100–300 °C). Reactivity of the surface acid sites was tested toward 2-propanal catalytic decomposition, and observed by in-situ IR gas phase spectra. Results obtained were correlated with predominant structures assumed by the supported tungstate species. Accordingly, polymerization of the supported tungstate into 2-/3-dimensional structures, was found to be relatively most advanced on favorable locations of titania surfaces as compared to the case on alumina or silica surfaces. Consequently, the Lewis acidity was strengthened, and strong Bronsted acidity was evolved, leading to a 2-propanol dehydration catalyst (tungstate/titania) of optimal activity and selectivity. Strong tungstate/support interfacial interactions were found to hamper the formation of the strongly acidic and catalytically active polymeric structures of the supported tungstate (i.e., the case on alumina or silica).

  11. Rapid differentiation and identification of five species of Salmonella by FT-IR spectroscopy%傅立叶变换红外光谱技术对5种沙门氏菌的快速分类鉴定

    Institute of Scientific and Technical Information of China (English)

    杨丽君; 李兆杰; 宋晓华; 王静; 刘玉敏; 崔凤杰

    2013-01-01

    [Objective] To establish a standard fourier transform infrared (FT-IR) spectral library and a FT-IR method of differentiation and identification of five species of Salmonella, viz Salmonella typhimurium, Salmonella enteritidis, Salmonella choleraesuis, Salmonella arizonae and Salmonella potsdam.[Methods] FT-IR fingerprint absorption spectra of five species of Salmonella were collected and analyzed by chemometric methods.[Results] A standard FT-IR spectral library was created and could be used to compare with those of the target Salmonella and identify them; two cluster models of principal component analysis (PCA) and hierarchical cluster analysis (HCA) were established and could differentiate and identify well the five species of Salmonella.[Conclusion] As a rapid, easy-to-use and accurate technique, FT-IR spectroscopy is an effective tool to differentiate and identify five species of Salmonella studied here.%[目的]建立沙门氏菌属内鼠伤寒沙门氏菌、肠炎沙门氏菌、猪霍乱沙门氏菌、亚利桑那沙门氏菌、波斯坦沙门氏菌5种菌的傅立叶变换红外(Fourier transform infrared,FT-IR)光谱数据库及FT-IR分类鉴定方法.[方法]应用FT-IR技术对5种沙门氏菌进行指纹图谱数据采集,应用化学计量学分析方法对光谱进行分析.[结果]建立了5种沙门氏菌的标准FT-IR光谱数据库,用于FT-IR技术对5种可疑目标沙门氏菌进行鉴定;建立了基于主成分分析(Principal component analysis,PCA)和分级聚类分析(Hierarchical cluster analysis,HCA)两种聚类分析模型,均可成功将5种沙门氏菌进行区分.[结论]傅立叶变换红外光谱分析方法简便、快速、易操作,结果重现性好,是一种区分5种沙门氏菌的有效方法.

  12. 基于热重红外的硫酸盐法黑液热解特性分析%TG-FT-IR Analysis of Pyrolysis Characteristics of Sulfate Black Liquor

    Institute of Scientific and Technical Information of China (English)

    刘超; 武书彬; 戴涛

    2014-01-01

    为了深入地探讨黑液热解的反应机理以及黑液热解过程中产物的释放规律,采用热重-红外联用( TG-FT-IR)技术对竹子和桉木混合硫酸盐法制浆黑液固形物( BLS)的热裂解过程进行了研究。 TG-FT-IR结果显示,BLS热解产物的释放主要集中在500~2000 s,热解产物主要是 CO2、CH4、H2O、CO、醇酚类化合物和醛酮类化合物。 BLS的整个热解过程可分为3个阶段,第1阶段的失重主要是原料中结合水的挥发引起的,此阶段的最大失重速率出现在105℃;第2失重阶段主要发生在173~518℃,失重率约为25.19%,主要产物是CO2、CH4、H2O、醇酚类化合物、醛酮类化合物以及少量的CO,此阶段CO2的生成量最大;第3阶段主要发生在722~1000℃,失重率接近39.05%,产物主要是CO,其它小分子产物的产率都很低。%To investigate the pyrolysis mechanism and the release law of pyrolysis products, the sulfate black liquor ( BLS) from bamboo&eucalyptus was pyrolyzed and the process was investigated by thermogravimetric analyzer coupled with Fourier transform infrared spectrometry ( TG-FT-IR) . The results revealed that the release of BLS pyrolysis products, such as CO2 , CH4 , H2 O, CO and alcohols & phenols, aldehydes & ketones, were mainly concentrated in 500-2 000 s. The BLS pyrolysis process could be divided into three stages. The weight loss in the first stage should be attributed to the release of bound water in the raw material and the maximum weight loss rate was observed at 105 ℃. During the second weight loss stage from 173 ℃ to 518 ℃, the weight loss rate was about 25. 19%, and the release products were CO2 , CH4 , H2 O, alcohols & phenols, aldehydes &ketones and a small amount of CO, and CO2 was the dominant product. The third weight loss stage was from 722℃ to 1 000℃, and the weight loss rate was nearly 39. 05%. In this stage, CO was the dominant product and very few amounts of other small molecule products

  13. Relationship between Oxidation of Unsaturated Natural Oils and Isomerization Characterized by FT-IR%FT-IR表征天然油脂不饱和结构氧化深度与异构化的关系

    Institute of Scientific and Technical Information of China (English)

    周华龙; 邹永鹏; 程正伟; 于华东; 熊江

    2013-01-01

    Plenty of researches and analysis prove that the oxidation of unsaturated oils is the generation of hydrogen peroxide (—OOH ) —the level - one oxidation reaction. And further research shows that the oxidation of the unsaturated oils is neither the epoxidation reaction, nor the traditional oxidation mechanism. The oxidation is performed in double bonds. Characterized by Fourier Transform Infrared Spectroscopy(FT - IR) , the unsaturated structural isomerization of common unsaturated natural plant oils and synthetic esters aggravates with oxidation depth increasing in the process of oxidation. And the unsaturated double bond structure changes from homeopathy into trans - structure. The more linoleic acid and linolenic acid contained in the unsaturated oils, the more obvious the degree of isomerization turns and the faster the speed of oxidation is.%经过大量的研究与分析,证明不饱和油脂的氧化生成是过氧化氢(-OOH)的一级氧化反应.进一步研究发现,不饱和油脂的氧化不是环氧化反应,更不是传统的氧化机理-氧化是在双键上发生的.通过红外光谱进行表征,常见的不饱和天然植物油脂、合成单酯在氧化过程中,随着氧化深度的加剧,其不饱和结构异构化加剧,即不饱和双键从顺势结构转变为反式结构;油脂的脂肪酸中含亚油酸、亚麻酸成分越多,异构化程度越明显,氧化速度越快.

  14. Quantum mechanical study and spectroscopic (FT-IR, FT-Raman, UV-Visible) study, potential energy surface scan, Fukui function analysis and HOMO-LUMO analysis of 3-tert-butyl-4-methoxyphenol by DFT methods.

    Science.gov (United States)

    Saravanan, S; Balachandran, V

    2014-09-15

    This study represents an integral approach towards understanding the electronic and structural aspects of 3-tert-butyl-4-methoxyphenol (TBMP). Fourier-transform Infrared (FT-IR) and Fourier-transform Raman (FT-Raman) spectra of TBMP was recorded in the region 4000-400 cm(-1) and 3500-100 cm(-1), respectively. The molecular structures, vibrational wavenumbers, infrared intensities and Raman activities were calculated using DFT (B3LYP and LSDA) methods using 6-311++G (d,p) basis set. The most stable conformer of TBMP was identified from the computational results. The assignments of vibrational spectra have been carried out with the help of normal co-ordinate analysis (NCA) following the scaled quantum mechanical force field (SQMFF) methodology. The first order hyperpolarizability (β0) and related properties (β, α0 and Δα) of TBMP have been discussed. The stability and charge delocalization of the molecule was studied by Natural Bond Orbital (NBO) analysis. UV-Visible spectrum and effects of solvents have been discussed and the electronic properties such as HOMO and LUMO energies were determined by time-dependent TD-DFT approach with B3LYP/6-311++G (d,p) level of theory. The molecule orbital contributions are studied by density of energy states (DOSs). The reactivity sites are identified by mapping the electron density into electrostatic potential surface (MEP). Mulliken analysis of atomic charges is also calculated. The thermodynamic properties at different temperatures were calculated, revealing the correlations between standard heat capacities, standard entropy and standard enthalpy changes with temperatures. Global hardness, global softness, global electrophilicity and ionization potential of the title compound are determined. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. FT—IR分析芳纶纸基纤维氢键结构%Analysis on the Structure of Hydrogen Bond of Aramid Paper Fibers by FT-IR

    Institute of Scientific and Technical Information of China (English)

    杨斌; 张美云; 李涛; 张素风

    2011-01-01

    高性能芳纶纤维除了刚性芳环结构贡献外,分子链之间的氢键结构也对其性能有显著影响。本研究采用傅里叶红外光谱分析方法,对比了不同芳纶纤维的红外吸收峰与吸收强度的差异性,揭示不同芳纶纤维表观结晶性能的差异性。研究结果表明:所用的3种芳纶纤维化学结构并无明显差别,而吸收强度的不同很大程度来源于大分子链之间的氢键缔合程度的不同。本方法可以应用于其他含酰胺键的聚合物纤维研究工作。%Aramid fiber not only has rigid aromatic rings, the organizational structure built by the hydrogen bond also have a significant impact on its performance. In this paper, classical analysis on aramid fiber by FT-IR has been used, it has clearly revealed that aramid fiber with different manufacturing process has different apparent crystalline properties. The results showed that: there is no difference in chemical structure with the three samples, there is the difference of absorptivity mostly because of the the difference of crystallinity. Aslo, the crystallinity of aramid pulp are lower than aramid fiber. This method can also be applied to other polymer fibers containing amide bond.

  16. HOMO-LUMO, UV, NLO, NMR and vibrational analysis of 3-methyl-1-phenylpyrazole using FT-IR, FT-RAMAN FT-NMR spectra and HF-DFT computational methods

    Science.gov (United States)

    Carthigayan, K.; Xavier, S.; Periandy, S.

    2015-05-01

    In this paper, the spectral analysis of 3-methyl-1-phenylpyrazole is carried out using the FT-IR, FT Raman, FT NMR and UV-Vis spectra with the help of quantum mechanical computations using HF and density functional theories. The different conformers of the compound and their minimum energies are studied using B3LYP functional with 6-311+G (d, p) basis set and the most stable conformer with minimum energy was identified and the same conformer was used for further computations. The computed wave numbers from different methods are scaled so as to agree with the experimental values and the scaling factors are reported. All the modes of vibrations are assigned and the structure the molecule is analyzed in terms of parameters like bond length, bond angle and dihedral angle predicted by both HF and B3LYP methods with 6-311+G (d, p) and 6-311++G (d, p) basis sets. The values of dipole moment (μ), polarizability (α) and hyperpolarizability (β) of the molecule are reported, using which the non-linear property of the molecule is discussed. The HOMO-LUMO mappings are reported which reveals the different charge transfer possibilities within the molecule. The isotropic chemical shifts predicted for 1H and 13C atoms using gauge invariant atomic orbital (GIAO) theory show good agreement with experimental shifts. NBO analysis is carried out to picture the charge transfer between the localized bonds and lone pairs. The thermodynamic properties (heat capacity, entropy and enthalpy) at different temperatures are also calculated.

  17. An experimental and theoretical investigation of Acenaphthene-5-boronic acid: conformational study, NBO and NLO analysis, molecular structure and FT-IR, FT-Raman, NMR and UV spectra.

    Science.gov (United States)

    Karabacak, Mehmet; Sinha, Leena; Prasad, Onkar; Asiri, Abdullah M; Cinar, Mehmet

    2013-11-01

    The solid state Fourier transform infrared (FT-IR) and FT-Raman spectra of Acenaphthene-5-boronic acid (AN-5-BA), have been recorded in the range 4000-400cm(-1) and 4000-10cm(-1), respectively. Density functional theory (DFT), with the B3LYP functional was used for the optimization of the ground state geometry and simulation of the infrared and Raman spectra of the molecule. The vibrational wave numbers and their assignments were examined theoretically using the Gaussian 09 set of quantum chemistry codes and the normal modes were assigned by a scaled quantum mechanical (SQM) force field approach. Hydrogen-bonded dimer of AN-5-BA, optimized by counterpoise correction, has also been studied by B3LYP at the 6-311++G(d,p) level and the effects of molecular association through O-H⋯O hydrogen bonding have been discussed. The (1)H and (13)C nuclear magnetic resonance (NMR) chemical shifts of the molecule were calculated by Gauge-Including Atomic Orbital (GIAO) method. Natural bond orbital (NBO) analysis has been applied to study stability of the molecule arising from charge delocalization. UV spectrum of the title compound was also recorded and the electronic properties, such as frontier orbitals, and band gap energies were measured by TD-DFT approach. The first order hyperpolarizability 〈β〉, its components and associated properties such as average polarizability and anisotropy of the polarizability (α and Δα) of AN-5-BA was calculated using the finite-field approach.

  18. Lipid profiles of adipose and muscle tissues in mouse models of juvenile onset of obesity without high fat diet induction: a Fourier transform infrared (FT-IR) spectroscopic study.

    Science.gov (United States)

    Sen, Ilke; Bozkurt, Ozlem; Aras, Ebru; Heise, Sebastian; Brockmann, Gudrun Anni; Severcan, Feride

    2015-06-01

    The current study aims to determine lipid profiles in terms of the content and structure of skeletal muscle and adipose tissues to better understand the characteristics of juvenile-onset spontaneous obesity without high fat diet induction. For the purposes of this study, muscle (longissimus, quadriceps) and adipose (inguinal, gonadal) tissues of 10-week-old male DBA/2J and Berlin fat mouse inbred (BFMI) lines (BFMI856, BFMI860, BFMI861) fed with a standard breeding diet were used. Biomolecular structure and composition was determined using attenuated total reflection Fourier transform (ATR FT-IR) spectroscopy, and muscle triglyceride content was further quantified using high-performance liquid chromatography (HPLC) coupled with an evaporative light scattering detector (ELSD). The results revealed a loss of unsaturation in BFMI860 and BFMI861 lines in both muscles and inguinal adipose tissue, together with a decrease in the hydrocarbon chain length of lipids, especially in the BFMI860 line in muscles, suggesting an increased lipid peroxidation. There was an increase in saturated lipid and triglyceride content in all tissues of BFMI lines, more profoundly in longissimus muscle, where the increased triglyceride content was quantitatively confirmed by HPLC-ELSD. Moreover, an increase in the metabolic turnover of carbohydrates in muscles of the BFMI860 line was observed. The results demonstrated that subcutaneous (inguinal) fat also displayed considerable obesity-induced alterations. Taken together, the results revealed differences in lipid structure and content of BFMI lines, which may originate from different insulin sensitivity levels of the lines, making them promising animal models for spontaneous obesity. The results will contribute to the understanding of the generation of insulin resistance in obesity without high fat diet induction.

  19. Rapid Differentiation and Identification of Three Species of Listeria by FT-IR Spectroscopy%傅立叶变换红外光谱技术对3种李斯特氏菌的快速分类鉴定

    Institute of Scientific and Technical Information of China (English)

    杨丽君; 李兆杰; 王静; 王骏; 胡巧茹; 刘玉敏; 崔凤杰

    2013-01-01

    To establish a standard fourier transform infrared (FT-IR) spectral library and a FT-IR method of differentiation and identification of three species of Listeria, viz Listeria monocytogenes, Listeria iuanuii and Listeria innocua, FT -IR fingerprint absorption spectra of three species of Listeria were collected, and a standard spectral derivatives library was created. Combined with chemometrics methods,two cluster models of principal component analysis (PCA) and hierarchical cluster analysis (HCA) were established. It was found that three species of Listeria could be well differentiated and identified, and the standard spectral derivatives library created could be used to compare with those of target Listeria and identify them. As a rapid, easy-to-use and accurate technique, FT-IR spectroscopy is an effective tool to differentiate and identify three species of Listeria studied here.%为建立李斯特氏菌属内单核细胞增生李斯特氏菌、绵羊李斯特氏菌、英诺克李斯特氏菌3种菌的傅立叶变换红外(Fourier transform infrared,FT-IR)光谱数据库及FT-IT分类鉴定方法,作者应用FT-IR技术对3种李斯特氏菌进行指纹图谱数据采集,建立了3种李斯特氏菌的标准FT-IR导数谱数据库,同时结合化学计量学分析方法,建立了基于主成分分析(principalcomponent analysis,PCA)和分级聚类分析(hierarchical cluster analysis,HCA)两种聚类分析模型.结果表明,两种聚类模型均可成功将3种李斯特氏菌进行区分,FT-IR光谱数据库可用于FT-IR技术对3种可疑李斯特氏菌进行鉴定.FT-IR分析方法简便、快速、易操作,结果重现性好,是一种区分3种李斯特氏菌的有效方法.

  20. 傅立叶变换红外光谱技术对2种葡萄球菌的快速分类鉴定%Rapid Differentiation and Identification of Staphylococcus aureus and Staphylococcus epidermidis by FT-IR spectroscopy

    Institute of Scientific and Technical Information of China (English)

    李兆杰; 王静; 隋涛; 宋晓华; 刘玉敏; 崔凤杰; 杨丽君

    2012-01-01

    [Objective] The research aimed to establish a standard Fourier transform infrared (FT-IR) spectral library and a FT-IR method of differentiation and identification of Staphylococcus aureus and Staphylococcus epidermidis. [Method] FT-IR fingerprint absorption spectra of two species of Staphylococcus were collected and analyzed by chemometric methods- [ Result ] A standard FT-IR spectral library was created and could be used to compare with those of the target Staphylococcus and identify them. A cluster model of principal component analysis was established and could differentiate and identify well the two species of Staphylococcus. [Conclusion] As a rapid, easy-to-use and accurate technique , FT-IR spectroscopy is an effective tool to differentiate and identify two species of Staphylococcus.%[目的]建立金黄色葡萄球菌和表皮葡萄球菌2种菌的傅立叶变换红外光谱数据库及FT-IT分类鉴定方法.[方法]应用FT-IR技术对2种葡萄球菌进行指纹图谱数据采集,应用化学计量学分析方法对光谱进行分析.[结果]建立2种葡萄球菌的标准FT-IR光谱数据库,用于FT-IR技术对2种可疑目标葡萄球菌进行鉴定;建立一种基于主成分分析的聚类分析模型,可成功地区分2种葡萄球菌.[结论]傅立叶变换红外光谱分析方法简便、快速、易操作,结果重现性好,是一种区分金黄色葡萄球菌和表皮葡萄球菌的有效方法.

  1. Direct Observation by Rapid-Scan FT-IR Spectroscopy of Two-Electron-Reduced Intermediate of Tetraaza Catalyst [Co(II)N4H(MeCN)](2+) Converting CO2 to CO.

    Science.gov (United States)

    Sheng, Hua; Frei, Heinz

    2016-08-10

    In the search for the two-electron-reduced intermediate of the tetraaza catalyst [Co(II)N4H(MeCN)](2+) (N4H = 2,12-dimethyl-3,7,11,17-tetraazabicyclo[11.3.1]heptadeca-1(17),2,11,13,15-pentaene) for CO2 reduction and elementary steps that result in the formation of CO product, rapid-scan FT-IR spectroscopy of the visible-light-sensitized catalysis, using Ir(ppy)3 in wet acetonitrile (CD3CN) solution, led to the observation of two sequential intermediates. The initially formed one-electron-reduced [Co(I)N4H](+)-CO2 adduct was converted by the second electron to a transient [Co(I)N4H](+)-CO2(-) complex that spontaneously converted CO2 to CO in a rate-limiting step on the second time scale in the dark under regeneration of the catalyst (room temperature). The macrocycle IR spectra of the [Co(I)N4H](+)-CO2(-) complex and the preceding one-electron [Co(I)N4H](+)-CO2 intermediate show close similarity but distinct differences in the carboxylate modes, indicating that the second electron resides mainly on the CO2 ligand. Vibrational assignments are corroborated by (13)C isotopic labeling. The structure and stability of the two-electron-reduced intermediate derived from the time-resolved IR study are in good agreement with recent predictions by DFT electronic structure calculations. This is the first observation of an intermediate of a molecular catalyst for CO2 reduction during the bond-breaking step producing CO. The reaction pathway for the Co tetraaza catalyst uncovered here suggests that the competition between CO2 reduction and proton reduction of a macrocyclic multi-electron catalyst is steered toward CO2 activation if the second electron is directly captured by an adduct of CO2 and the one-electron-reduced catalyst intermediate.

  2. Reversible dimer formation and stability of the anti-tumour single-chain Fv antibody MFE-23 by neutron scattering, analytical ultracentrifugation, and NMR and FT-IR spectroscopy.

    Science.gov (United States)

    Lee, Yie Chia; Boehm, Mark K; Chester, Kerry A; Begent, Richard H J; Perkins, Stephen J

    2002-06-28

    MFE-23 is a single chain Fv (scFv) antibody molecule used to target colorectal cancer through its high affinity for the tumour marker carcinoembryonic antigen (CEA). ScFv molecules are formed from peptide-linked antibody V(H) and V(L) domains, and many of these form dimers. Our recent crystal structure for MFE-23 showed that this formed an unusual symmetric back-to-back association of two monomers that is consistent with a domain-swapped diabody structure. Neutron scattering and modelling fits showed that MFE-23 existed as compact V(H)-V(L)-linked monomers at therapeutically relevant concentrations below 1 mg/ml. Size-exclusion gel chromatography showed that the monomeric and dimeric forms of MFE-23 could be separated, and that the proportions of these two forms depended on the starting MFE-23 concentration. Sedimentation equilibrium experiments by analytical ultracentrifugation at nine concentrations of MFE-23 indicated a reversible monomer-dimer self-association equilibrium with an association constant of 1.9x10(3)-2.2x10(3) M(-1). Sedimentation velocity experiments using the time derivative g(s(*)) method showed that MFE-23-His has a concentration-dependent weight average sedimentation coefficient that increased from 1.8 S for the monomer to about 3-6 S for the dimer. Both values agreed with those calculated from the MFE-23 crystal structure. In relation to the thermal stability of MFE-23, denaturation experiments by (1)H NMR and FT-IR spectroscopy showed that the molecule is stable up to 47 degrees C, after which denaturation was irreversible. MFE-23 dimerisation is discussed in terms of a new model for diabody structures, in which the V(H) and V(L) domains in the monomer are able to dissociate and reassociate to form a dimer, or diabody, but in which symmetric back-to-back contacts between the two monomers are formed. This dimerisation in solution is attributed to the complementary nature of the C-terminal surface of the MFE-23 monomer. Crystal structures for

  3. Experimental, computational and chemometrics studies of BSA-vitamin B6 interaction by UV-Vis, FT-IR, fluorescence spectroscopy, molecular dynamics simulation and hard-soft modeling methods.

    Science.gov (United States)

    Manouchehri, Firouzeh; Izadmanesh, Yahya; Aghaee, Elham; Ghasemi, Jahan B

    2016-10-01

    The interaction of pyridoxine (Vitamin B6) with bovine serum albumin (BSA) is investigated under pseudo-physiological conditions by UV-Vis, fluorescence and FTIR spectroscopy. The intrinsic fluorescence of BSA was quenched by VB6, which was rationalized in terms of the static quenching mechanism. According to fluorescence quenching calculations, the bimolecular quenching constant (kq), dynamic quenching (KSV) and static quenching (KLB) at 310K were obtained. The efficiency of energy transfer and the distance between the donor (BSA) and the acceptor (VB6) were calculated by Foster's non-radiative energy transfer theory and were equal to 41.1% and 2.11nm. The collected UV-Vis and fluorescence spectra were combined into a row-and column-wise augmented matrix and resolved by multivariate curve resolution-alternating least squares (MCR-ALS). MCR-ALS helped to estimate the stoichiometry of interactions, concentration profiles and pure spectra for three species (BSA, VB6 and VB6-BSA complex) existed in the interaction procedure. Based on the MCR-ALS results, using mass balance equations, a model was developed and binding constant of complex was calculated using non-linear least squares curve fitting. FT-IR spectra showed that the conformation of proteins was altered in presence of VB6. Finally, the combined docking and molecular dynamics (MD) simulations were used to estimate the binding affinity of VB6 to BSA. Five-nanosecond MD simulations were performed on bovine serum albumin (BSA) to study the conformational features of its ligand binding site. From MD results, eleven BSA snapshots were extracted, at every 0.5ns, to explore the binding affinity (GOLD score) of VB6 using a docking procedure. MD simulations indicated that there is a considerable flexibility in the structure of protein that affected ligand recognition. Structural analyses and docking simulations indicated that VB6 binds to site I and GOLD score values depend on the conformations of both BSA and ligand

  4. 维生素C反相微乳液的构建及红外光谱研究%Construction and FT-IR Investigation of Vitamin C Reverse Microemulsions

    Institute of Scientific and Technical Information of China (English)

    孟照永; 王如梅; 赵新; 韩正; 王仲妮

    2015-01-01

    Objective To construct Vitamin C (Vit C) encapsulated microemulsions by employing isoamyl acetate, isopropyl myristate, sunflower oil or castor oil as the continuous phase and analyze their infrared spectral (IR) properties. Methods The ternary phase diagrams were constructed by water-dilution method to determine the phase behaviors of aqueous solution of nonionic surfactant polyoxyethylene (10) oleyl ether (Brij97) in isoamyl acetate, isopropyl myristate, sunflower oil and castor oil;the reverse emulsions were formed with Brij97, oil phase and Vit C, and the structural difference of the microemulsion systems with or without Vit C was investigated through FT-IR;the O-H stretching vibration peak and micro-environment of each microemulsion system were analyzed using Gaussian curve fitting method. Results Reverse microemulsions have been formed with Brij97 aqueous solution in four oils respectively. FT-IR measurements and analyses indicated after solubilization of Vit C, the fourth new Gaussian peak in high frequency zone is obtained for the O-H stretching vibration of the microemulsion. The new peak waved irregularly along with changes of oil concentration in the isoamyl acetate and isopropyl myristate systems, while moved to lower frequency region along with the decrease of oil content for the sunflower oil and castor oil systems. Conclusion It is more effective in forming reverse microemulsion with isoamyl acetate and isopropyl myristate as continuous phase than with sunflower oil or castor oil as continuous phase. In addition, FR-IR spectra showed that Vit C was completely wrapped into the hydrophilic kernel of reverse microemulsion, and the multipeak fitting results showed that the introduction of Vit C resulted in a new combined water in the microenvironment of the system.%目的:分别构筑以乙酸异戊酯、肉豆蔻酸异丙酯、葵花籽油和蓖麻油为连续相的包载维生素C(Vit C)微乳液,并研究其红外光谱(IR)性质。方法

  5. In situ FT-IR study on CO oxidation over Co3O4/CeO2 catalyst%Co3O4/CeO2CO氧化的原位红外光谱研究

    Institute of Scientific and Technical Information of China (English)

    邵建军; 朱锡; 张永坤; 王明贵

    2012-01-01

    Co3O4/CeO2 catalyst was prepared by co-precipitation-oxidation method. Adsorption of carbon monoxide and the co-adsorption of CO/O2 over Co3O4/CeO2 sample were investigated. In situ FT-IR analysis of the mechanism in CO oxidation was interpreted over Co3O4/CeO2 sample. Effects of the reaction conditions on the catalytic performance over Co3O4/CeO2 catalyst for carbon monoxide oxidation was investigated at humid and dry conditions. Results indicated that the addition of cerium to the cobalt oxide was beneficial for CO oxidation over Co3O4 at humid condition. The formation of carbonate species with reaction on Co3O4/CeO2 composite oxide slightly deactivated the catalyst. When the temperature was as low as 453 K, the dynamic equilibrium of formation and decomposition of carbonate species existed in Co3O4/CeO2 composite oxide catalyst. The carbonate species disappeared above 493 K. The strong interaction between CeO2 and Co3O4 may contribute to the excellent water resistance for low-temperature CO oxidation over Co3O4/CeO2 catalyst at humid condition.%采用沉淀氧化法制备了Co3O4/CeO2催化剂.分别在干、湿条件下进行了一氧化碳氧化反应研究.运用FT-IR表征手段,在钴铈复合氧化物上进行了CO吸附及CO/O2共吸附研究.结果表明,与纯的Co3O4样品相比,Co3O4/CeO2具有明显的抗湿气能力.Co3O4/CeO2催化剂在进行CO氧化时,表面形成了类碳酸盐物种.当环境温度低于453K时,催化剂上类碳酸盐的生成与形成类碳酸盐物种后受热分解存在着动态平衡.当环境温度高于493K,催化剂上生成的类碳酸盐物全部受热分解.氧化铈的加入提高了催化剂的抗湿气性能.较小粒径的Co3O4与CeO2产生的强相互作用可使CeO2向Co3O4提供氧,因而间接提供了CO氧化需要的氧.

  6. Quantum mechanical and spectroscopic (FT-IR, FT-Raman,1H,13C NMR, UV-Vis) studies, NBO, NLO, HOMO, LUMO and Fukui function analysis of 5-Methoxy-1H-benzo[d]imidazole-2(3H)-thione by DFT studies

    Science.gov (United States)

    Pandey, Manju; Muthu, S.; Nanje Gowda, N. M.

    2017-02-01

    Theoretical analysis of the molecular structure, spectroscopic (FT-IR, FT-Raman, 1H, 13C NMR, UV-Vis) studies, and thermodynamic characteristics of 5-Methoxy-1H-benzo[d]imidazole-2(3H)-thione (5MBIT) molecule were done by DFT/B3LYP using 6-311++G(d, p) basis set. Theoretical parameters were compared with experimental data. The dipole moment (μ), polarizability (Δα) and first order hyperpolarizability (β) of the molecule were calculated. Thermodynamic properties, HOMO and LUMO energies were determined. Global reactivity parameters and Fukui function of the 5MBIT molecule were predicted.

  7. Solvent effect in implicit/explicit model on FT-IR, 1H, 13C and 19F NMR, UV-vis and fluorescence spectra, linear, second- and third-nonlinear optical parameters of 2-(trifluoromethyl)benzoic acid: Experimental and computational study

    Science.gov (United States)

    Avcı, Davut; Altürk, Sümeyye; Tamer, Ömer; Kuşbazoğlu, Mustafa; Atalay, Yusuf

    2017-09-01

    FT-IR, 1H, 13C and 19F NMR, UV-vis and fluorescence spectra for 2-(trifluoromethyl)benzoic acid (2-TFMBA) were recorded. DFT//B3LYP/6-31++G(d,p) calculations were used to determine the optimized molecular geometry, vibrational frequencies, 1H, 13C and 19F GIAO-NMR chemical shifts of 2-TFMBA. The detailed assignments of vibrational frequencies were carried out on the basis of potential energy distribution (PED) by using VEDA program. TD-DFT/B3LYP/6-31++G(d,p) calculations with the PCM (polarizable continuum model) in ethanol and DMSO solvents based on implicit/explicit model and gas phase in the excited state were employed to investigate UV-vis absorption and fluorescence emission wavelengths. The UV-vis and emission spectra were given in ethanol and DMSO solvents, and the major contributions to the electronic transitions were obtained. In addition, the NLO parameters (β, γ and χ(3)) and frontier molecular orbital energies of 2-TFMBA were calculated by using B3LYP/6-31++G(d,p) level. The NLO parameters of 2-TFMBA were compared with that of para-Nitroaniline (pNA) and urea which are the typical NLO materials. The refractive index (n) is calculated by using the Lorentz-Lorenz equation to observe polarization behavior of 2-TFMBA in DMSO and ethanol solvents. In order to investigate intramolecular and hydrogen bonding interactions, NBO calculations were also performed by the same level. To sum up, considering the well-known biological role, photochemical properties of 2-TFMBA were discussed.

  8. Experimental and theoretical (FT-IR, FT-Raman, UV-vis, NMR) spectroscopic analysis and first order hyperpolarizability studies of non-linear optical material: (2E)-3-[4-(methylsulfanyl) phenyl]-1-(4-nitrophenyl) prop-2-en-1-one using density functional theory.

    Science.gov (United States)

    Kumar, Amit; Deval, Vipin; Tandon, Poonam; Gupta, Archana; Deepak D'silva, E

    2014-09-15

    A combined experimental and theoretical investigation on FT-IR, FT-Raman, NMR, UV-vis spectra of a chalcone derivative (2E)-3-[4-(methylsulfanyl) phenyl]-1-(4-nitrophenyl) prop-2-en-1-one (4N4MSP) has been reported. 4N4MSP has two planar rings connected through conjugated double bond and it provides a necessary configuration to show non-linear optical (NLO) response. The molecular structure, fundamental vibrational frequencies and intensity of the vibrational bands are interpreted with the aid of structure optimizations and normal coordinate force field calculations based on density functional theory (DFT) with B3LYP functional and 6-311++G(d,p) basis set combination. The analysis of the fundamental modes was made with the help of potential energy distribution (PED). Molecular electrostatic potential (MEP) surface was plotted over the geometry primarily for predicting sites and relative reactivities towards electrophilic and nucleophilic attack. The delocalization of electron density of various constituents of the molecule has been discussed with the aid of NBO analysis. The electronic properties, such as excitation energies, oscillator strength, wavelengths, HOMO and LUMO energies, were calculated by time-dependent density functional theory (TD-DFT) and the results complement the experimental findings. The recorded and calculated 1H chemical shifts in gas phase and MeOD solution are gathered for reliable calculations of magnetic properties. Thermodynamic properties like heat capacity (C°p,m), entropy (S°m), enthalpy (H°m) have been calculated for the molecule at the different temperatures. Based on the finite-field approach, the non-linear optical (NLO) parameters such as dipole moment, mean polarizability, anisotropy of polarizability and first order hyperpolarizability of 4N4MSP molecule are calculated. The predicted first hyperpolarizability shows that the molecule has a reasonably good nonlinear optical (NLO) behavior.

  9. 基于FT-IR对不同脱木素程度尾巨桉内部化学结构的分析%Analysis on chemical structure of Eucalyptus organdies with different levels of delignification based on FT-IR

    Institute of Scientific and Technical Information of China (English)

    侯广强; 韩卿

    2013-01-01

    In this paper, Eucalyptus urograndis fibers were treated with delignification in different extent, then the chemical structure components of Eucalyptus urograndis fibers contained different lignin content were analyzed, DP of cellulose were researched, and results were characterized by FT-IR, in order to find out the relationship between the delignification extent and cellulose degradation and the rule of its structure changes during delignification process. The results show that DP of cellulose reduced along with reduction of lignin, and the fastest rate of delignification and`the maximum degradation happened in the process within 2~3 h. According to the FT-IR, carbohydrate structure gradually exposed and more hydroxyl group, uronic acids and COO- end group emerged in the whole process.%  对尾巨桉进行不同程度脱木素处理,然后对不同木素含量的尾巨桉进行组分、聚合度和FT-IR分析,研究木素去除程度和纤维素降解之间的关系以及处理过程中纤维内各组分化学结构的变化。结果表明:纤维素聚合度随木素含量的减少不断降低,在处理2~3h时间内,木素含量下降最快,纤维素降解也最为严重;脱木素过程中糖类大分子结构逐步裸露出来,并出现了较多的游离羟基、糖醛酸小分子和COO-末端基。

  10. Aplicação de análise multivariada aos dados de espectroscopia no infravermelho obtidos na polimerização in situ de adesivo à base de cianoacrilato Multivariate analyses on FT-IR data of polymerization in situ of cyanoacrylate adhesive

    Directory of Open Access Journals (Sweden)

    Francisco A. A. Miranda

    1998-06-01

    Full Text Available A polimerização de adesivo à base de cianoacrilato foi acompanhada por FT-IR durante 30 minutos. A aplicação das técnicas de estatística multivariada (análise de agrupamento hierárquico e a análise dos componentes principais aos espectros de infravermelho, permitiram uma melhor identificação das diferenças espectrais entre monômero e polímero e possibilitou, também, inferir que a quantidade de monômero e do mero no polímero se eqüivalem com seis minutos de polimerização. A técnica de infravermelho mostrou-se uma ferramenta adequada para o acompanhamento da cinética de reação de adesivo à base de cianoacrilato, que torna-se ainda mais eficiente quando associada às técnicas de estatística multivariada.The polymerization of a cyanoacrylate adhesive was accompanied by FT-IR during 30 minutes. The application of multivariate statistics techniques (Hierarchical Clusters Analyses and Principal Components on infrared spectra allowed a better identification of spectral differences between monomer and polymer and also permitted to infer that the quantity of monomer and of mer of the polymer are equal in six minutes polymerization (half-life. The infrared technique appeared as an apropriate tool for observing the kinetics of cyanoacrylate adhesive reaction, which becomes even more efficient when associated to multivariate statistics techniques.

  11. Curve-Fitting Analysis of Micro FT-IR and Its Application on Individual Oil Inclusion and Micro-Area Bitumens%单个油包裹体和微区沥青显微红外光谱 分峰拟合技术及应用

    Institute of Scientific and Technical Information of China (English)

    王倩茹; 陈红汉; 胡守志; 赵玉涛; 陈慧钦

    2016-01-01

    Curve-fitting analysis of micro FT-IR,in the theory of Gaussian,Lorentz function or their combination (Gaussian-Lorentz)model,can break through the limit of overlapping spectra resulting from complicated structures of samples (e.g.indi-vidual oil inclusion and bitumens).Hence,curve-fitting analysis of micro FT-IR was used for analyzing maturity of individual oil inclusion and the origin of bitumens in Shuntuoguole area of Tazhong northeastern slope systematically,and four conclusions have been obtained:firstly,curve-fitting analysis of micro FT-IR may be more accurate for calculating absorption peaks,and some easily neglected peaks can be detected by this method in contrast with the method of interval oriented by Pironon.Second-ly,Gaussian-Lorentz fitting is more approaching to actual spectra and the lower noise level is corresponding to better fit but re-quiring longer computation time.As a result,Gaussian-Lorentz fitting with 1~10 noise level is preferred.Thirdly,based on in-clusion system analysis and burial history projection with homogenization temperature,infrared parameters (e.g.CH2a/CH3a, Xinc and Xstd)reveal three hydrocarbon charging events occurred,including Late Caledonian,Late Hercynian and the Himala-ya.Finally,micro FT-IR is an effective means for analyzing multi-hydrocarbon charging events and complicated origin of bitu-mens undergoing biodegradation,oxidative degradation and water eluviation quantitatively in study area.%针对单个油包裹体和储层沥青等结构复杂样品傅里叶变换显微红外光谱吸收峰严重重叠的问题,基于高斯、洛伦茨函数或其组合(高斯-洛伦茨)模型理论,采用显微红外分峰拟合技术,对塔中北坡顺托果勒地区单个油包裹体成熟度和储层沥青成因进行了系统分析,并取得了4点认识:(1)通过与Pironon对合成油包裹体的峰位坐标区域化划分吸收峰对比,认为分峰拟合技术更为真实地反映各子峰的面积,而且能够识别重叠区

  12. Vibrational investigation on FT-IR and FT-Raman spectra, IR intensity, Raman activity, peak resemblance, ideal estimation, standard deviation of computed frequencies analyses and electronic structure on 3-methyl-1,2-butadiene using HF and DFT (LSDA/B3LYP/B3PW91) calculations.

    Science.gov (United States)

    Ramalingam, S; Jayaprakash, A; Mohan, S; Karabacak, M

    2011-11-01

    FT-IR and FT-Raman (4000-100 cm(-1)) spectral measurements of 3-methyl-1,2-butadiene (3M12B) have been attempted in the present work. Ab-initio HF and DFT (LSDA/B3LYP/B3PW91) calculations have been performed giving energies, optimized structures, harmonic vibrational frequencies, IR intensities and Raman activities. Complete vibrational assignments on the observed spectra are made with vibrational frequencies obtained by HF and DFT (LSDA/B3LYP/B3PW91) at 6-31G(d,p) and 6-311G(d,p) basis sets. The results of the calculations have been used to simulate IR and Raman spectra for the molecule that showed good agreement with the observed spectra. The potential energy distribution (PED) corresponding to each of the observed frequencies are calculated which confirms the reliability and precision of the assignment and analysis of the vibrational fundamentals modes. The oscillation of vibrational frequencies of butadiene due to the couple of methyl group is also discussed. A study on the electronic properties such as HOMO and LUMO energies, were performed by time-dependent DFT (TD-DFT) approach. The calculated HOMO and LUMO energies show that charge transfer occurs within the molecule. The thermodynamic properties of the title compound at different temperatures reveal the correlations between standard heat capacities (C) standard entropies (S), and standard enthalpy changes (H).

  13. Thermal analysis of paracetamol polymorphs by FT-IR spectroscopies.

    Science.gov (United States)

    Zimmermann, Boris; Baranović, Goran

    2011-01-25

    A simple IR spectroscopy based methodology in routine screening studies of polymorphism is proposed. Reflectance and transmittance temperature-dependent IR measurements (coupled with the 2D-IR data presentation and the baseline analysis) offer a positive identification of each polymorphic phase, therefore allowing simple and rapid monitoring of the measured system. Applicability and flexibility of the methodology was demonstrated on the measurement of the model polymorphic compound paracetamol under various conditions (including geometric constraints and elevated pressure). The thermal behavior of paracetamol strongly depends on slight variations in experimental conditions that can result in formation of various phases (three polymorphs and the amorphous form). The amorphous phase can crystallize during heating into either Form II or Form III within almost identical temperature range. Likewise, the crystal transformations II→I and III→II also can proceed within almost identical temperature range. Furthermore, the thermal behavior is even more diverse than that, and includes the crystallizations of Forms I, II and III from the melt, and the high temperature II→I transition. The variety of the temperatures of the transformations is a major obstacle for unambiguous identification of a particular phase by DSC and a major reason for the implementation of these IR methods.

  14. Determination of Ethanol in Gasoline by FT-IR Spectroscopy

    Science.gov (United States)

    Conklin, Alfred, Jr.; Goldcamp, Michael J.; Barrett, Jacob

    2014-01-01

    Ethanol is the primary oxygenate in gasoline in the United States. Gasoline containing various percentages of ethanol is readily available in the market place. A laboratory experiment has been developed in which the percentage of ethanol in hexanes can easily be determined using the O-H and alkane C-H absorptions in an infrared spectrum. Standard…

  15. FT-IR, NMR SPECTROSCOPIC and QUANTUM MECHANICAL ...

    African Journals Online (AJOL)

    ... and The Authors. Printed in Ethiopia ..... often attributed to the neglected anharmonicity and incomplete inclusion of electronic correlation ... molecule receptor systems using ferrocene's “atomic ball bearing” character as the flexible element.

  16. Preliminary Discrimination of Cheese Adulteration by FT-IR Spectroscopy

    Directory of Open Access Journals (Sweden)

    Lucian Cuibus

    2014-11-01

    Full Text Available The present work describes a preliminary study to compare some traditional Romanian cheeses and adulterated cheeses using Attenuated Total Reflectance-Fourier transform infrared spectroscopy (ATR-FTIR. For PLS model calibration (6 concentration levels and validation (5 concentration levels sets were prepared from commercial Dalia Cheese from different manufacturers by spiking it with palm oil at concentrations ranging 2-50 % and 5-40 %, respectively. Fifteen Dalia Cheese were evaluated as external set. The spectra of each sample, after homogenization, were acquired in triplicate using a FTIR Shimatsu Prestige 21 Spectrophotometer, with a horizontal diamond ATR accessory in the MIR region 4000-600 cm-1. Statistical methods as PLS were applied using MVC1 routines written for Matlab R2010a. As first step the optimal condition for PLS model were obtained using cross-validation on the Calibration set. Spectral region in 3873-652 cm-1, and 3 PLS-factors were stated as the best conditions and showed an R2 value of 0.9338 and a relative error in the calibration of 17.2%. Then validation set was evaluated, obtaining good recovery rates (108% and acceptable dispersion of the data (20%. The curve of actual vs. predicted values shows slope near to 1 and origin close to 0, with an R2 of 0.9695. When the external sample set was evaluated, samples F19, F21, F22 and F24, showed detectable levels of palm fats. The results proved that FTIR-PLS is a reliable non-destructive technique for a rapid quantification the level of adulteration in cheese.  The spectroscopic methods could assist the quality control authority, traders and the producers to discriminate the adulterated cheeses with palm oil.

  17. Water analysis of glass ceramics by FT-IR spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Nease, A B; Hale, M D; Kramer, D P

    1983-12-15

    A method for measuring water concentration in glasses has been described and the results of the study of ten batches of glasses have been tabulated. It has been shown that infrared spectroscopy is a satisfactory tool for measuring water concentration in glass ceramics. The water concentrations of ten batches of glass have been shown to differ significantly, and these variances are associated with environmental humidity and glass preparation method.

  18. 5-羟甲基糠醛热解机理的 PY-GC-MS及原位红外法分析%Analysis of Pyrolysis Mechanism of 5-Hydroxymethyl Furfural by Using PY-GC-MS and In-Situ FT-IR

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    采用PY-GC-MS(快速热裂解-色质联用)对5-羟甲基糠醛(5-HMF)进行热裂解实验,发现裂解产物中将近86%为呋喃环类物质,同时存在小分子物质,表明其热解主要为侧链降解,但也存在呋喃环的开环断裂。结合原位红外光谱分析,实时监测5-HMF热裂解产物随反应过程的转化规律,发现在130~230℃之间主要生成糠醛、5-甲基糠醛,250℃后主要生成2-糠醇及5-乙酰甲氧基-2-糠醛,这两者的生成持续至反应中后期;作为5-HMF热解最主要产物的2,5-呋喃二甲醛的生成则在整个反应过程持续进行。结合快速热解及原位红外实验结果,推测5-HMF的热解机理如下:侧链羟甲基处连续两次脱氢生成2,5-呋喃二甲醛是最主要的反应,羟甲基去羟基后加氢生成5-甲基糠醛,羟甲基侧链及醛基侧链的整体断裂分别生成糠醛及糠醇,在此基础上还会发生二次裂解反应生成2-甲基呋喃。%Pyrolysis experiments of 5-hydroxymethyl furfural (5-HMF) were conducted and the product composi-tion was detected by using a PY-GC-MS analyzer .The results show that nearly 86%of the pyrolysis product is fu-ran ring-contained substance , and that a certain amount of small molecules exist in the product , which means that the pyrolysis process of 5-HMF is mainly a side-chain degradation process concomitantly with the fracture of furan rings.Moreover, the converting law of the product in the pyrolysis process was supervised in real time via in-situ FT-IR.The results show that furfural and 5-methyl furfural mainly form when the temperature ranges from 130 to 230℃, furfuryl alcohol and 5-formyl-2-furfurylacetate mainly form after 250℃ and the formation continues to the middle and later periods of the whole process , while the dominant pyrolysis product of 5-HMF, namely furan-2, 5-dicarbaldehyde , forms throughout the whole pyrolysis process .According to the results obtained

  19. Synthesis, crystal structure analysis, spectral (NMR, FT-IR, FT-Raman and UV-Vis) investigations, molecular docking studies, antimicrobial studies and quantum chemical calculations of a novel 4-chloro-8-methoxyquinoline-2(1H)-one: An effective antimicrobial agent and an inhibition of DNA gyrase and lanosterol-14α-demethylase enzymes

    Science.gov (United States)

    Murugavel, S.; Sundramoorthy, S.; Lakshmanan, D.; Subashini, R.; Pavan Kumar, P.

    2017-03-01

    The novel title compound 4-chloro-8-methoxyquinoline-2(1H)-one (4CMOQ) has been synthesized by slow evaporation solution growth technique at room temperature. The synthesized 4CMOQ molecule was characterized experimentally by FT-IR, FT-Raman, UV-Vis, NMR and single crystal diffraction (XRD) and theoretically by quantum chemical calculations. The molecular geometry was also optimized using density functional theory (DFT/B3LYP) method with the 6-311++G (d,p) basis set in ground state and compared with the experimental data. The entire vibrational assignments of wave numbers were made on the basis of potential energy distribution (PED) by VEDA 4 programme. The nuclear magnetic resonance spectra (1H and 13C NMR) are obtained by using the gauge-invariant atomic orbital (GIAO) method. The change in electron density (ED) in the antibonding orbital's and stabilization energies E(2) of the molecule have been evaluated by natural bond orbital (NBO) analysis to give clear evidence of stabilization. Moreover, electronic characteristics such as HOMO and LUMO energies, Mulliken atomic charges and molecular electrostatic potential surface are investigated. Absorption spectrum analysis, nonlinear optical properties, chemical reactivity descriptors and thermodynamic features are also outlined theoretically. Molecular docking studies were executed to understand the inhibitory activity of 4CMOQ against DNA gyrase and Lanosterol 14 α-demethylase. The antimicrobial activity of 4CMOQ was determined against bacterial strains such as Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa and fungal strains such as Aspergillus niger, Monascus purpureus and Penicillium citrinum. The obtained results show that the compound exhibited good to moderate antimicrobial activity.

  20. Molecular structure, spectral investigation (1H NMR, 13C NMR, UV-Visible, FT-IR, FT-Raman), NBO, intramolecular hydrogen bonding, chemical reactivity and first hyperpolarizability analysis of formononetin [7-hydroxy-3(4-methoxyphenyl)chromone]: A quantum chemical study

    Science.gov (United States)

    Srivastava, Anubha; Mishra, Rashmi; Kumar, Sudhir; Dev, Kapil; Tandon, Poonam; Maurya, Rakesh

    2015-03-01

    Formononetin [7-hydroxy-3(4-methoxyphenyl)chromone or 4‧-methoxy daidzein] is a soy isoflavonoid that is found abundantly in traditional Chinese medicine Astragalus mongholicus (Bunge) and Trifolium pretense L. (red clover), and in an Indian medicinal plant, Butea (B.) monosperma. Crude extract of B.monosperma is used for rapid healing of fracture in Indian traditional medicine. In this study, a combined theoretical and experimental approach is used to study the properties of formononetin. The optimized geometry was calculated by B3LYP method using 6-311++G(d,p) as a large basis set. The FT-Raman and FT-IR spectra were recorded in the solid phase, and interpreted in terms of potential energy distribution (PED) analysis. Density functional theory (DFT) is applied to explore the nonlinear optical properties of the molecule. Good consistency is found between the calculated results and observed data for the electronic absorption, IR and Raman spectra. The solvent effects have been calculated using time-dependent density functional theory in combination with the integral equation formalism polarized continuum model, and the results are in good agreement with observed measurements. The double well potential energy curve of the molecule about the respective bonds, have been plotted, as obtained from DFT/6-31G basis set. The computational results diagnose the most stable conformer of formononetin. The HOMO-LUMO energy gap of possible conformers has been calculated for comparing their chemical activity. Chemical reactivity has been measured by reactivity descriptors and molecular electrostatic potential surface (MEP). The 1H and 13C NMR chemical shifts of the molecule were calculated by the Gauge including atomic orbital (GIAO) method. Furthermore, the role of CHsbnd O intramolecular hydrogen bond in the stability of molecule is investigated on the basis of the results of topological properties of AIM theory and NBO analysis. The calculated first hyperpolarizability shows

  1. In situ FT-IR studies on low temperature NH3-SCR mechanism of NOx over MnOx/WO3/TiO2catalyst%MnOx/WO3/TiO2低温选择性催化还原NOx机理的原位红外研究

    Institute of Scientific and Technical Information of China (English)

    廖永进; 张亚平; 余岳溪; 李娟; 郭婉秋; 汪小蕾

    2016-01-01

    15% MnOx/5% WO3/ TiO2catalyst for low-temperature selective catalytic reduction of NOx was synthesized by an impregnation method. NH3-SCR mechanism was explored systematically and possible pathway was proposed throughin situ FT-IR study on microscopic transient and steady states under various conditions of single or mixed gas feed with multiple pre-treatment. The results revealed that NH3-SCR reaction over the 15%MnOx/5%WO3/TiO2catalyst proceeded mainly by the Eley-Rideal mechanism with the Langmuir- Hinshclwood pathway only at certain temperature. NH3 adsorbed on the Lewis acid sites of the catalyst surface was the main source of reductant; however, more NH+4adsorbed on the Brønsted acid sites of the catalyst surface involved in the NOx reduction with increase of reaction temperature. The adsorption and activation of NH3was key step for the whole SCR reaction. NO2 easily reacted with adsorbed NH3 with stronger affinity to catalyst surface than NO. The bidentate nitrate, which formed considerably at oxidation active centers of the catalyst by NO adsorption, didn’t participate in NH3-SCR reaction but obstructed adsorption and activation of NH3. O2could promote NH3-SCR by blocking formation of bidentate nitrate. The adsorption of NO and NH3 on the catalyst surface was competitive at room temperature, which NO adsorption was higher than NH3 at O2 absence. The absorbed NH3 could be massively activated and reacted with NOxupon temperature reached to 100℃.%浸渍法制备15% MnOx/5% WO3/TiO2低温脱硝催化剂,利用原位傅里叶变换红外(in situ FT-IR)设计包括多种吸附反应以及不同预处理方式的微观暂态试验与微观稳态试验,研究其NH3-SCR脱硝反应机理,并推测反应路径。结果表明,催化剂的 NH3-SCR 反应主要以 Eley-Rideal 机理方式进行,仅在一定温度条件下可以看到Langmuir-Hinshclwood反应路径。催化剂表面Lewis酸位的NH3吸附是还原剂的主要来

  2. Structure Development of Bombyx Mori Silk During Heating Study In Situ Wide-Angle X-Ray Scattering and FT-IR%原位显微红外和X射线研究升温过程中桑蚕丝微观结构变化

    Institute of Scientific and Technical Information of China (English)

    张瑞静; 邵春光; 李倩; 曹伟; 张阳; 刘成刚; 申长雨

    2012-01-01

    The microstructure and surface morphology evolution of degummed Bombyx mori silk were investigated by X-ray diffraction,FT-IR microscope and polarization microscope over a broad temperature range from 30 ℃ to 300 ℃.The results indicate that the thermal expansion coefficients of lattice are highly anisotropic along a and b axial during heating.The thermal expansion coefficient along a axial is much smaller than that along b axial because of strong hydrogen bonding force along a axial.Besides,the crystallinity of baves begins to increase from 180 ℃ for the transition from the random coil to β-sheet,and decrease significantly at 280 ℃ when the carbonization occurs.It is also found that the degree of orientation increases slightly during the entire heating process.%在30℃~300℃温度范围内利用二维广角X射线、显微红外光谱(FT-IR)和偏光显微镜原位检测升温过程中脱胶桑蚕丝微观结构的变化。结果表明,升温过程中,晶格的膨胀系数沿a轴和b轴表现出明显的各向异性,具有氢键作用的a轴方向晶格膨胀系数远远小于b轴方向;温度〈180℃时,蚕丝结晶度变化不明显,但温度≥180℃,结晶度开始升高,部分分子链由无规线团构象向β-sheet构象转变;由于纤维的炭化,280℃以后蚕丝的结晶度开始显著下降;整个加热过程中,晶体的取向度略微增加。

  3. Conformational and structural studies of 1-chloropropane and 1-bromopropane from temperature-dependant FT-IR spectra of rare gas solutions and ab initio calculations

    Science.gov (United States)

    Durig, J. R.; Zhu, X.; Shen, S.

    2001-08-01

    Variable temperature (-55 to -150°C) studies of the infrared spectra (3500-400 cm -1) of 1-chloropropane (CH 3CH 2CH 2Cl) and 1-bromopropane (CH 3CH 2CH 2Br) dissolved in liquid krypton and xenon, respectively, have been recorded. Utilizing two conformer pairs in krypton solution for chloride and three conformer pairs in xenon solution for bromide, enthalpy differences of 52±3 cm -1 (0.62±0.06 kJ/mol) and 72±7 cm -1 (0.86±0.08 kJ/mol) were obtained for the chloride and bromide, respectively, with the gauche form being the more stable conformer for both molecules. From these data, it is estimated that 28 and 26% of trans form are present at ambient temperature for the chloride and bromide, respectively. The conformation stabilities, harmonic force constants, fundamental frequencies, infrared intensities and Raman activities have been obtained from RHF/6-31G(d) and/or MP2/6-31G(d) ab initio calculations for both halopropanes and these quantities have been compared to the experimental values when appropriate. The optimized geometries have also been obtained with several different ab initio basis sets with full electron correlation by the perturbation method up to MP2/6-311+G(2d,2p). The r0 structural parameters of both halopropanes have been obtained by combining the ab initio data with the previously reported microwave rotational constants for both conformers. The quantities are compared to the corresponding results for some similar molecules.

  4. Quantitative Analysis of Adsorbate Concentrations by Diffuse Reflectance FT-IR

    OpenAIRE

    Phanichphant, S; Meunier, Frederic; Sirita, S.

    2007-01-01

    Fully quantitative analyses of DRIFTS data are required when the surface concentrations and the specific rate constants of reaction (or desorption) of adsorbates are needed to validate microkinetic models. The relationship between the surface coverage of adsorbates and various functions derived from the signal collected by DRIFTS is discussed here. The Kubelka-Munk and pseudoabsorbance (noted here as absorbance, for the sake of brevity) transformations were considered, since those are the mos...

  5. FT-Raman, FT-IR spectroscopic and DFT studies of hexaphenoxycyclotriphosphazene

    Science.gov (United States)

    Furer, V. L.; Vandyukov, A. E.; Padie, C.; Majoral, J. P.; Caminade, A. M.; Kovalenko, V. I.

    2016-07-01

    The FTIR and FT Raman measurements of zero Gc0‧ -H and first Gc1‧ -H generations of phosphorus dendrimer built from cyclotriphosphazene core with phenoxy and deuterophenoxy terminal groups have been performed. In order to evaluate how much the frequencies, shift when changing the electronics of the system the FTIR and FT Raman spectra of phosphorus‒containing dendron with five terminal oxybenzaldehyde and one ester function Gci‧ have been also studied. Structural optimization and normal mode analysis were obtained for Gc0‧ -H and Gc0‧ -D by the density functional theory (DFT). It is discovered that dendrimer molecule exists in a stable conformation with six phenoxy terminal groups spaced above and below the flat cyclotriphosphazene core. Optimized geometric bond length and angles obtained by DFT show good agreement with a previously-published X-ray study. The phenoxy terminal groups are characterized by the well-defined line at 993 cm-1 in the experimental Raman spectrum of Gc0‧ -H and by line at 960 cm-1 in the Raman spectrum of Gc0‧ -D. Relying on DFT calculations a complete vibrational assignment is proposed for the studied dendrimers. The frequencies and relative intensity of the bands at 1589, 1487 cm-1 in the IR spectra show marked difference in dependence of the substituents on the aromatic ring.

  6. Detection of metanil yellow contamination in turmeric using FT-Raman and FT-IR spectroscopy

    Science.gov (United States)

    Turmeric is well known for its medicinal value and is often used in Asian cuisine. Economically motivated contamination of turmeric by chemicals such as metanil yellow has been repeatedly reported. Although traditional technologies can detect such contaminants in food, high operational costs and ope...

  7. Analytical methodology for authentication of Ropinirole using HPLC and FT-IR

    Directory of Open Access Journals (Sweden)

    Abhishek Chandra

    2015-03-01

    Full Text Available Ropinirole hydrochloride is a modern selective non-ergoline dopamine D2-like receptor agonist with affinity for D2, D3 and D4 receptor subtypes, indicated for the treatment of the signs and symptoms of Parkinson’s disease and moderate-to severe primary RLS (Restless Legs Syndrome. It hasmoderate in vitro affinity for the opioid receptors. Ropinirole HCl is weakly active at the 5-HT2, and α2 receptors and is said to have virtually no affinity for the 5-HT1, benzodiazepine, GABA, muscarinic, α1 and β-adrenoreceptors. Ropinirole is metabolized primarily by cytochrome P450 CYP1A2, and at doses higher than clinical, is also metabolized by CYP3A4. At doses greater than 24 mg, CYP2D6 may be inhibited, although this has only been tested in vitro. Ropinirole HCl is a highly water soluble drug. UV spectroscopic studies show that ropinirole HCl gives maximum absorbance at λmax 250nm. Ropinirole HCL has been characterized by HPLC method which was achieved on a C18(250 x 4.6mm 5 – micron Hypersil BDS using a mobile phase consisting of a degassed mixture of 0.05m glacial acetic acid (2.85 ml of glacial acetic acid in 1000 mL of water and acetonitrile (50:50 with a flow rate of 1.0 mL/min. The mobile phase showed most favorable chromatographic parameter for analysis. The detection of the constituent was done using UV detector at 250nm.The retention time of ropinirole HCl was found to be 3.566 minutes. Ropinirole HCl was further characterized on the basis of FTIR studies.

  8. MEMS based miniature FT-IR engine with built-in photodetector

    Science.gov (United States)

    Warashina, Yoshihisa; Suzuki, Tomofumi; Kasamori, Kohei; Okumura, Ryosuke; Matsuo, Yuki; Takemura, Mitsutaka

    2014-03-01

    A MEMS-FTIR engine has been developed as a key device for the Fourier-Transform Infrared Spectrometer, which consists of a Michelson interferometer including an electro-static actuator to control a moving mirror, an optical fiber groove for incident light and a photodetector. All these elements except for the photodetector are monolithically fabricated in Silicon using MEMS technology. The optical elements such as a beam splitter, a fixed mirror and a moving mirror are formed and aligned simultaneously with high degree of precision by Deep Reactive Ion Etching (DRIE). The vertical side walls are utilized as optical planes so that the incident light path is located in parallel with the Silicon substrate. The moving mirror is driven by an electro-static MEMS actuator. The photodetector is placed above an angled mirror, which is formed by alkaline wet etching exposing the Silicon crystal plane at the end position of light path. All the elements including the photodetector are hermetically covered by a lid of Silicon in the vacuum chamber by using a surface activate bonding technology. In order to reduce the cost, wafer level process and separation of each chip by a laser dicer after all assembly processes are introduced. The realized MEMS-FTIR is 10×17×1 mm in size and a signal noise ratio (SNR) of better than 35dB, which comes from a good verticality of less than 0.2 degree in the vertical side walls as optical planes by managing the DRIE etching conditions.

  9. FT-IR and 29 Si-NMR for evaluating aluminium silicate precursors for geopolymers

    NARCIS (Netherlands)

    Valcke, S.L.A.; Pipilikaki, P.; Fischer, H.R.; Verkuijlen, M.H.W.; Eck, E.R.H.

    2014-01-01

    Geopolymers are systems of inorganic binders that can be used for sustainable, cementless concrete and are formed by alkali activation of an aluminium–silicate precursor (often secondary resources like fly ash or slag). The type of aluminium– silicate precursor and its potential variations within on

  10. Using FT-IR spectroscopy to measure charge organization in ionic liquids.

    Science.gov (United States)

    Burba, Christopher M; Janzen, Jonathan; Butson, Eric D; Coltrain, Gage L

    2013-07-25

    A major goal in the field of ionic liquids is correlating transport property trends with the underlying liquid structure of the compounds, such as the degree of charge organization among the constituent ions. Traditional techniques for experimentally assessing charge organization are specialized and not readily available for routine measurements. This represents a significant roadblock in elucidating these correlations. We use a combination of transmission and polarized-ATR infrared spectroscopy to measure the degree of charge organization for ionic liquids. The technique is illustrated with a family of 1-alkyl-3-methylimidazolium trifluoromethanesulfonate ionic liquids at 30 °C. As expected, the amount of charge organization decreases as the alkyl side chain is lengthened, highlighting the important role of short-range repulsive interactions in defining quasilattice structure. Inherent limitations of the method are identified and discussed. The quantitative measurements of charge organization are then correlated with trends in the transport properties of the compounds to highlight the relationship between charge and momentum transport and the underlying liquid structure. Most research laboratories possess infrared spectrometers capable of conducting these measurements; thus, the proposed method may represent a cost-effective solution for routinely measuring charge organization in ionic liquids.

  11. Coordination properties of warfarin towards Pr(III) predicted from DFT and FT-IR studies

    Energy Technology Data Exchange (ETDEWEB)

    Mihaylov, Tz., E-mail: tzmihay@svr.igic.bas.bg [Institute of General and Inorganic Chemistry, Bulgarian Academy of Sciences, Sofia (Bulgaria); Trendafilova, N.; Georgieva, I. [Institute of General and Inorganic Chemistry, Bulgarian Academy of Sciences, Sofia (Bulgaria); Kostova, I., E-mail: irenakostova@yahoo.com [Department of Chemistry, Faculty of Pharmacy, Medical University, Sofia (Bulgaria)

    2010-08-23

    Graphical abstract: The coordination behavior of warfarin towards Pr(III) in Pr(L){sub 3}.5H{sub 2}O complex (L - warfarin) is investigated through molecular modeling at B3LYP/6-31G(d,p) level and consequent exhaustive comparative vibrational analysis of the ligand and the complex. The calculations predicted that the ligand binds to the metal through the deprotonated enol group and the keto C=O group in pseudo-octahedral polyhedron. The simulated vibrational spectrum of the model complex proposed is in excellent agreement with the experimental one. - Abstract: The coordination behavior of warfarin towards Pr(III) in Pr(L){sub 3}.5H{sub 2}O complex (L - warfarin) is investigated through molecular modeling at B3LYP/6-31G(d,p) level and consequent exhaustive comparative vibrational analysis of the ligand and the complex. The calculated NPA charges, Fukui functions and MEP values of the anionic ligand in solution pointed out that the oxygen atoms of the deprotonated hydroxyl and the coumarin carbonyl groups are the most probable reactive sites upon coordination. The metal-ligand binding mode of warfarin is predicted through molecular modeling and energy estimation of different Pr(III)-warfarin structures. In the most stable model structure, the ligand-metal binding is realized through the oxygen of the deprotonated OH group and the oxygen of the keto C=O group in pseudo-octahedral polyhedron. The suggested metal-ligand binding mode is confirmed by comparative vibrational analysis of the free ligand and various model structures with different metal-ligand binding modes.

  12. In-situ Microscopic FT-IR Spectroelectrochemical Investigation of Polythiophene Film Modified Electrode

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A polythiophene film was electrochemically deposited on a Pt micro-plate electrode and investigated by cyclic voltammetry and in-situ reflection microscopic FTIR spectroscopy. The FTIR analysis showed that the electropolymerization of thiophene on the Pt surface was affected by the surface adsorption processes of thiophene molecules. Two adsorption modes were identified. Two structure models of the polythiophene chain were observed simultaneously. It was proposed that the good conductibility of the polythiophene film was originated from a co-vibratory equilibrium of the link part of model Ⅰ and model Ⅱ.

  13. Intramolecular hydrogen bonds in crystals of thiophosphorylbenzopyrane derivatives X-ray and FT-IR studies

    Science.gov (United States)

    Rybarczyk-Pirek, Agnieszka J.; Dubis, Alina T.; Grabowski, Sławomir J.; Nawrot-Modranka, Jolanta

    2006-01-01

    The crystal structures of two new benzopyrane derivatives are analyzed and compared with previous X-ray investigations on related compounds. A particular attention is focused on intramolecular interactions. For the chromone derivatives ( 1 and 3) only one kind of interaction is possible, i.e., N-H⋯O, whereas for the coumarine derivatives ( 2 and 4) two types of intramolecular hydrogen bonding are observed - N-H⋯O and O-H⋯N. Two types of H-bond for coumarine derivatives are the result of the existence of two tautomeric forms - enamine and iminoenol. Combined spectroscopic, NMR and IR measurements confirm such tautomeric equilibrium in solution. The influence of the additional intermolecular hydrogen bonds on the stabilization of tautomeric forms in crystals is also discussed here.

  14. Ageing of Starch Based Systems as observed with FT-IR and Solid State NMR Spectroscopy

    NARCIS (Netherlands)

    Smits, A.L.M.; Ruhnau, F.C.; Vliegenthart, J.F.G.; Soest, van J.J.G.

    1998-01-01

    The retrogradation and physical ageing of model starch systems with respect to their glass transition temperatures Tg have been investigated by Fourier transform infrared spectroscopy and solid state NMR spectroscopy. Diffuse reflectance Fourier transform infrared (DRIFT) spectra demonstrate the com

  15. Ageing of starch based systems as observed with FT-IR and solid state NMR spectroscopy

    NARCIS (Netherlands)

    Vliegenthart, J.F.G.; Smits, A.L.M.; Ruhnau, F.C.; Soest, J.J.G. van

    1998-01-01

    The retrogradation and physical ageing of model starch systems with respect to their glass transition temperatures Tg have been investigated by Fourier transform infrared Spectroscopy and solid state NMR spectroscopy. Diffuse reflectance Fourier transform infrared (DRIFT) spectra demonstrate the com

  16. GC/FT-IR ANALYSIS OF THE THERMALLY LABILE COMPOUND TRIS (2,3-DIBROMOPROPYL) PHOSPHATE

    Science.gov (United States)

    A fast and convenient GC method has been developed for a compound [tris(2,3-dibromopropyl)phosphate] that poses a difficult analytical problem for both GC (thermal instability/low volatility) and LC (not amenable to commonly available, sensitive detectors) analysis. his method em...

  17. Imaging of human colon carcinoma thin sections by FT-IR microspectrometry

    Science.gov (United States)

    Lasch, Peter; Waesche, Wolfgang; McCarthy, W. J.; Mueller, Gerhard J.; Naumann, Dieter

    1998-04-01

    FTIR microspectroscopic maps of unstained colon carcinoma thin sections were obtained on a conventional IR microscope equipped with an automatic x, y stage, or alternatively by using a MCT focal plane array detector system. IR data were analyzed by different image re-assembling techniques. One main goal of the present study was to test the influence of different spectra data compression approaches on the quality of the FTIR images. The images, re-assembled by Principal component analysis (PCA) on the basis of spectral information available from the fingerprint region exhibited an excellent image contrast confirming standard histo- pathological examinations. The second approach included a systematic search for spectral windows which were supposed to contain the relevant information, necessary for spectra classification and identification. Data from these spectral windows were analyzed by an ANN and output data were utilized for image construction. In contrast to the PCA approach, the image contrast was lower although the main morphological structures were exactly classified. From the spectroscopic point of view, the spectral feature selection method delivered useful information which could be discussed in terms of structural alternations upon carcinogenesis.

  18. GC/FT-IR ANALYSIS OF THE THERMALLY LABILE COMPOUND TRIS (2,3-DIBROMOPROPYL) PHOSPHATE

    Science.gov (United States)

    A fast and convenient GC method has been developed for a compound [tris(2,3-dibromopropyl)phosphate] that poses a difficult analytical problem for both GC (thermal instability/low volatility) and LC (not amenable to commonly available, sensitive detectors) analysis. his method em...

  19. Characterization of the curing agents used in epoxy resins with TG/FT-IR technique

    OpenAIRE

    Benedita M. V. Romão; Diniz,Milton F.; Margarete F. P. Azevedo; Vera L. Lourenço; Luiz C. Pardini; Rita C.L. Dutra; Fabrice Burel

    2006-01-01

    Samples of epoxy resin (EP) based on the diglycidyl ether of bisphenol A (DGEBA), cured with nadic methyl anhydride (NMA) and mercaptan (CAPCURE 3-800), or amine-phenol (CAPCURE EH-30), respectively, SE 4 and SE 5, were prepared in the stoichiometric ratio determined by the supplier. The curing behaviour of the epoxy systems SE 4 and SE 5 was followed by DSC (Differential Scanning Calorimetry). These SE and their ingredients were analyzed using FTIR transmission techniques (KBr pellets, pyrol...

  20. Spectroscopic study on the active site of a SiO2 supported niobia catalyst used for the gas-phase Beckmann rearrangement of cyclohexanone oxime to ε-caprolactam

    NARCIS (Netherlands)

    Maronna, M M; Kruissink, E C; Parton, R F; Soulimani, F; Weckhuysen, B M; Hoelderich, W F

    2016-01-01

    NbOx/SiO2 with a very high catalytic activity for the gas-phase Beckmann rearrangement of cyclohexanone oxime to ε-caprolactam, was investigated by different spectroscopic methods in order to obtain new insights in the formation and nature of the active sites. FT-IR spectroscopy in combination with

  1. Evaluation of turmeric powder adulterated with metanil yellow using FT-Raman and FT-IR spectroscopy

    Science.gov (United States)

    Turmeric powder (Curcuma longa L.) is valued both for its medicinal properties and for its popular culinary use such as being a component in curry powder. Due to its high demand in international trade, turmeric powder has been subject to economically driven, hazardous chemical adulteration. This stu...

  2. COMPOSITION DETERMINATION OF MULTI-COMPONENT ORGANIC AEROSOLS BY ON-LINE FT-IR SPECTROSCOPY. (R826767)

    Science.gov (United States)

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  3. Direct, non-destructive, and rapid evaluation of developmental cotton fibers by ATR FT-IR spectroscopy

    Science.gov (United States)

    Chemical, compositional, and structural differences within the fibers at different growth stages have been investigated considerably through a number of methodologies. Due to its direct, non-destructive, and rapid attribute, this study reports the utilization of attenuated total reflection Fourier t...

  4. FT-IR and computer modeling study of hydrogen bonding in N-alkyl acrylamide-toluene binary mixtures

    Science.gov (United States)

    Rumyantsev, Misha; Kazantsev, Oleg A.; Kamorina, Sofia I.; Kamorin, Denis M.; Sivokhin, Alexey P.

    2016-10-01

    Degree of hydrogen bonding driven self-association of N-(n-butyl)acrylamide, N-(n-octyl)acrylamide, N-(sec-octyl)acrylamide and N-(tert-octyl)acrylamide in toluene was investigated using IR spectroscopy and computer modeling methods. Consistent results were demonstrated in the treatment of the Amide-I (νC=O), Amide-II (δN-H and νC-N) and Amide-A (νN-H) absorption bands in IR spectra. Thus, the content of non-bonded (free) amide groups decreases from 83-98% to 8-20% and the content of linear polyassociates increases to 80-90% with an increase in monomer concentration from 0.5 wt% to 50 wt%. The content of cyclic dimers was equal to the value between 5 and 10% regardless of the initial monomer concentration. Dependences of the association degree and the content of the linear polyassociates on the concentration were found to be similar for all of the studied amides.

  5. Hydrogen-producing Escherichia coli strains overexpressing lactose permease: FT-IR analysis of the lactose-induced stress.

    Science.gov (United States)

    Grube, Mara; Dimanta, Ilze; Gavare, Marita; Strazdina, Inese; Liepins, Janis; Juhna, Talis; Kalnenieks, Uldis

    2014-01-01

    The lactose permease gene (lacY) was overexpressed in the septuple knockout mutant of Escherichia coli, previously engineered for hydrogen production from glucose. It was expected that raising the lactose transporter activity would elevate the intracellular lactose concentration, inactivate the lactose repressor, induce the lactose operon, and as a result stimulate overall lactose consumption and conversion. However, overexpression of the lactose transporter caused a considerable growth delay in the recombinant strain on lactose, resembling to some extent the "lactose killing" phenomenon. Therefore, the recombinant strain was subjected to selection on lactose-containing media. Selection on plates with 3% lactose yielded a strain with a decreased content of the recombinant plasmid but with an improved ability to grow and produce hydrogen on lactose. Macromolecular analysis of its biomass by means of Fourier transform-infrared spectroscopy demonstrated that increase of the cellular polysaccharide content might contribute to the adaptation of E. coli to lactose stress.

  6. The FT-IR studies of the interactions of CO2 and polymers having different chain groups

    NARCIS (Netherlands)

    Nalawade, SP; Picchioni, F; Marsman, JH; Janssen, LPBM; Nalawade, Sameer P.

    A Fourier transform-infrared spectroscopy (Fr-IR) set up has been successfully modified in order to characterize different polymeric materials under sub- and supercritical CO2 conditions. Polymers used in this study are polyesters (P120 and P130), poly(ethylene glycol) (PEG) and polyphenylene oxide

  7. The first observation of memory effects in the infrared (FT-IR) measurements: do successive measurements remember each other?

    Science.gov (United States)

    Nigmatullin, Raoul R; Osokin, Sergey I; Baleanu, Dumitru; Al-Amri, Sawsan; Azam, Ameer; Memic, Adnan

    2014-01-01

    Over the past couple of decades there have been major advances in the field of nanoscience and nanotechnology. Many applications have sprouted from these fields of research. It is essential, given the scale of the materials, to attain accurate, valid and reproducible measurements. Material properties have shown to be a function of their size and composition. Physiochemical properties of the nanomaterials can significantly alter material behavior compared to bulk counterparts. For example, metal oxide nanoparticles have found broad applications ranging from photo-catalysis to antibacterial agents. In our study, we synthesized CuO nanoparticles using well established sol-gel based methods with varying levels of Ni doping. However, upon analysis of measured infrared data, we discovered the presence of quasi-periodic (QP) processes. Such processes have previously been reported to be tightly associated with measurement memory effects. We were able to detect the desired QP process in these measurements from three highly accurate repetitive experiments performed on each Ni (1-7%) doped CuO sample. In other words, successive measurements performed in a rather short period of time remember each other at least inside a group of neighboring measurements.

  8. Laser-Raman and FT-IR spectroscopic studies of peptide-analogues of silkmoth chorion protein segments.

    Science.gov (United States)

    Benaki, D C; Aggeli, A; Chryssikos, G D; Yiannopoulos, Y D; Kamitsos, E I; Brumley, E; Case, S T; Boden, N; Hamodrakas, S J

    1998-07-01

    Silkmoth chorion, the proteinaceous major component of the eggshell, with extraordinary mechanical and physiological properties, consists of a complex set of proteins, which have a tripartite structure: a central, evolutionarily conserved, domain and two more variable 'arms'. Peptide-analogues of silkmoth chorion protein central domain segments have been synthesized. Laser-Raman and infrared spectroscopic studies suggest the preponderance of antiparallel beta-pleated sheet structure for these peptides, both in solution and in the solid state.

  9. Preparation and Characterization of the Phenolated Wood Using Sulfuric Acid as a Catalyst Ⅱ. FT-IR and GPC Characterization

    Institute of Scientific and Technical Information of China (English)

    IKEDA; Atsushi

    2003-01-01

    By means of gel permeation chromatography analysis, the molecular weight of liquefied wood under different reaction conditions was investigated to trace the change in the structural characteristics of the liquefied wood. The insoluble residues were analyzed by Fourier transform infrared to investigate the liquefaction order of three main wood components. The results indicate that both reaction temperature and reaction time could affect the molecular characteristics of the liquefied wood obtained. The mo...

  10. Use of ATR FT-IR spectroscopy in non-destructive and rapid assessment of developmental cotton fibers

    Science.gov (United States)

    The knowledge of chemical and compositional components in cotton fibers is of value to cotton breeders and growers for cotton enhancement and to textile processors for quality control. In this work, we applied the previously proposed simple algorithms to analyze the attenuated total reflection Fouri...

  11. A review of the main factors influencing the FT-IR-PLS abilities exemplified with petrochemical qualimetric applications.

    Science.gov (United States)

    Andrade, J M; Garcia, M V; Lopez-Mahia, P; Prada, D

    1997-12-01

    Quality control usually involves monitoring several variables directly related with industrial necessities using univariate tests. One powerful alternative is to link multivariate analytical techniques and multivariate chemometrics. In this way, Fourier Transform Infrared spectroscopy and Partial Least Squares regression are used to discuss and review several advantages and drawbacks encountered in using such combination in industrial facilities. Typical drawbacks are selection of data pretreatment, errors in reference methods, selection of calibration and validation sets and model-aging. This review is exemplified with petrochemical applications although other fields are also considered (mainly when dealing with data pretreatment).

  12. FT-IR spectroscopy as a tool for the study of the quality of processed meat products

    Directory of Open Access Journals (Sweden)

    Murcia, M. Antonia

    1994-10-01

    Full Text Available Attenuated total reflectance Fourier transform infrared spectroscopy has been used to characterize processed meat products. Proteins were estimated through the amide I band centered at 1650 cm-1 and lipids through the carbonyl stretching band at 1735 cm-1.
    Estimations of protein/lipid ratios were obtained by dividing the area under the 1650 cm-1 band by the area under the 1735 cm-1 band. These protein/lipid ratios correlated well with those obtained for the same samples using conventional chemical analysis. Attenuated total reflectance Fourier transform infrared spectroscopy is therefore a quick and analytical technique with the advantage over other procedures of being non destructive and which can be used to assess the quality of processed meat products.

    Se ha utilizado la espectroscopia de infrarrojo de transformada de Fourier por reflectancia total atenuada para caracterizar productos cárnicos procesados. Las proteínas se valoraron a través de la banda amida I centrada a 1650 cm-1 y los lípidos por la banda de tensión del carbonilo a 1735 cm-1.
    Los valores de los cocientes proteína/lípido fueron calculados dividiendo el área bajo la banda a 1650 cm-1 por el área bajo la banda a 1735 cm-1. Los cocientes proteína/lípido se correlacionan bien con aquellos obtenidos para las mismas muestras usando análisis químicos convencionales. La espectroscopia de infrarrojo de transformada de Fourier por reflectancia total atenuada es una técnica analítica rápida y con la ventaja sobre otros métodos de ser no destructiva, que puede ser usada para determinar la calidad de productos cárnicos procesados.

  13. FT-IR spectroscopy and multivariate analysis as an auxiliary tool for diagnosis of mental disorders: Bipolar and schizophrenia cases

    Science.gov (United States)

    Ogruc Ildiz, G.; Arslan, M.; Unsalan, O.; Araujo-Andrade, C.; Kurt, E.; Karatepe, H. T.; Yilmaz, A.; Yalcinkaya, O. B.; Herken, H.

    2016-01-01

    In this study, a methodology based on Fourier-transform infrared spectroscopy and principal component analysis and partial least square methods is proposed for the analysis of blood plasma samples in order to identify spectral changes correlated with some biomarkers associated with schizophrenia and bipolarity. Our main goal was to use the spectral information for the calibration of statistical models to discriminate and classify blood plasma samples belonging to bipolar and schizophrenic patients. IR spectra of 30 samples of blood plasma obtained from each, bipolar and schizophrenic patients and healthy control group were collected. The results obtained from principal component analysis (PCA) show a clear discrimination between the bipolar (BP), schizophrenic (SZ) and control group' (CG) blood samples that also give possibility to identify three main regions that show the major differences correlated with both mental disorders (biomarkers). Furthermore, a model for the classification of the blood samples was calibrated using partial least square discriminant analysis (PLS-DA), allowing the correct classification of BP, SZ and CG samples. The results obtained applying this methodology suggest that it can be used as a complimentary diagnostic tool for the detection and discrimination of these mental diseases.

  14. Low inversion energy barrier of cytisine NH group—an explanation for the FT-IR bands splitting

    Science.gov (United States)

    Rode, Joanna E.; Raczyńska, Ewa D.; Górnicka, Elżbieta; Dobrowolski, Jan Cz.

    2005-07-01

    The DFT calculations using B3PW91 hybrid functional and 6-311++G** basis set were performed for the two most stable isomers of cytisine ( 1a and 1b). The conformation 1a differs from 1b by the orientation ( equatorial and axial, respectively) of the hydrogen atom at the piperidine nitrogen atom. In terms of the Gibbs free energy, the conformation 1a is less stable than 1b by 0.25 kcal mol -1, only. The isomers are separated by 3.6 kcal mol -1—an activation energy barrier, which is higher in energy than the vibrational modes inverting one isomer into another. Presence of such a barrier explains the existence of the two isomers ( equatorial and axial) observed previously in apolar solvents.

  15. Aqueous Solvation of Ammonia and Ammonium: Probing Hydrogen Bond Motifs with FT-IR and Soft X-ray Spectroscopy.

    Science.gov (United States)

    Ekimova, Maria; Quevedo, Wilson; Szyc, Łukasz; Iannuzzi, Marcella; Wernet, Philippe; Odelius, Michael; Nibbering, Erik T J

    2017-09-13

    In a multifaceted investigation combining local soft X-ray and vibrational spectroscopic probes with ab initio molecular dynamics simulations, hydrogen-bonding interactions of two key principal amine compounds in aqueous solution, ammonia (NH3) and ammonium ion (NH4(+)), are quantitatively assessed in terms of electronic structure, solvation structure, and dynamics. From the X-ray measurements and complementary determination of the IR-active hydrogen stretching and bending modes of NH3 and NH4(+) in aqueous solution, the picture emerges of a comparatively strongly hydrogen-bonded NH4(+) ion via N-H donating interactions, whereas NH3 has a strongly accepting hydrogen bond with one water molecule at the nitrogen lone pair but only weakly N-H donating hydrogen bonds. In contrast to the case of hydrogen bonding among solvent water molecules, we find that energy mismatch between occupied orbitals of both the solutes NH3 and NH4(+) and the surrounding water prevents strong mixing between orbitals upon hydrogen bonding and, thus, inhibits substantial charge transfer between solute and solvent. A close inspection of the calculated unoccupied molecular orbitals, in conjunction with experimentally measured N K-edge absorption spectra, reveals the different nature of the electronic structural effects of these two key principal amine compounds imposed by hydrogen bonding to water, where a pH-dependent excitation energy appears to be an intrinsic property. These results provide a benchmark for hydrogen bonding of other nitrogen-containing acids and bases.

  16. Structural modifications of Tilia cordata wood during heat treatment investigated by FT-IR and 2D IR correlation spectroscopy

    Science.gov (United States)

    Popescu, Maria-Cristina; Froidevaux, Julien; Navi, Parviz; Popescu, Carmen-Mihaela

    2013-02-01

    It is known that heat treatment of wood combined with a low percent of relative humidity causes transformations in the chemical composition of it. The modifications and/or degradation of wood components occur by hydrolysis, oxidation, and decarboxylation reactions. The aim of this study was to give better insights on wood chemical modifications during wood heat treatment under low temperature at about 140 °C and 10% percentage of relative humidity, by infrared, principal component analysis and two dimensional infrared correlation spectroscopy. For this purpose, hardwood samples of lime (Tilia cordata) were investigated and analysed. The infrared spectra of treated samples were compared with the reference ones, the most important differences being observed in the "fingerprint" region. Due to the complexity of this region, which have contributions from all the wood constituents the chemical changes during hydro-thermal treatment were examined in detail using principal component analysis and 2D IR correlation spectroscopy. By hydro-thermal treatment of wood results the formation of acetic acid, which catalyse the hydrolysis reactions of hemicelluloses and amorphous cellulose. The cleavage of the β-O-4 linkages and splitting of the aliphatic methoxyl chains from the aromatic lignin ring was also observed. For the first treatment interval, a higher extent of carbohydrates degradation was observed, then an increase of the extent of the lignin degradation also took place.

  17. Photoinduced FT-IR spectroscopy of conjugated polymer/fullerene composites embedded into conventional host polymer matrices

    NARCIS (Netherlands)

    Johansson, H.; Brabec, C.J.; Neugebauer, H.; Kvarnstrom, C.; Hummelen, J.C.; Janssen, R.A.J.; Sariciftci, N.S.

    1999-01-01

    In this work, we report on the investigation of photoexcited states in conjugated polymer (donor) - fullerene (acceptor) interpenetrating networks (polythiophene derivatives - PC61BM) embedded into conventional polymer hosts like polystyrene, polyvinylcarbazole, polycarbonate or polyvinylbenzenechlo

  18. Analysis of Complex Carbohydrate Composition in Plant Cell Wall Using Fourier Transformed Mid-Infrared Spectroscopy (FT-IR).

    Science.gov (United States)

    Badhan, Ajay; Wang, Yuxi; McAllister, Tim A

    2017-01-01

    Fourier transformed mid-infrared spectroscopy (FTIR) is a powerful tool for compositional analysis of plant cell walls (Acebes et al., Front Plant Sci 5:303, 2014; Badhan et al., Biotechnol Biofuels 7:1-15, 2014; Badhan et al., BioMed Res Int 2015: 562952, 2015; Roach et al., Plant Physiol 156:1351-1363, 2011). The infrared spectrum generates a fingerprint of a sample with absorption peaks corresponding to the frequency of vibrations between the bonds of the atoms making up the material. Here, we describe a method focused on the use of FTIR in combination with principal component analysis (PCA) to characterize the composition of the plant cell wall. This method has been successfully used to study complex enzyme saccharification processes like rumen digestion to identify recalcitrant moieties in low-quality forage which resist rumen digestion (Badhan et al., BioMed Res Int 2015: 562952, 2015), as well as to characterize cell wall mutant lines or transgenic lines expressing exogenous hydrolases (Badhan et al., Biotechnol Biofuels 7:1-15, 2014; Roach et al., Plant Physiol 156:1351-1363, 2011). The FTIR method described here facilitates high-throughput identification of the major compositional differences across a large set of samples in a low cost and nondestructive manner.

  19. Structural diversity of metal phytate compounds: a solid state C-13 NMR and FT-IR spectroscopic investigation

    Science.gov (United States)

    Phytate (myo-inositol-1,2,3,4,5,6-hexakisphosphate) is the major organic phosphorus component in the environment. Phytate contains a 6-carbon ring with 1 hydrogen and 1 phosphate attached to each carbon. Each of the 6 phosphate groups is attached in an ester linkage. Phytate exists in aqueous soluti...

  20. The first observation of memory effects in the infrared (FT-IR measurements: do successive measurements remember each other?

    Directory of Open Access Journals (Sweden)

    Raoul R Nigmatullin

    Full Text Available Over the past couple of decades there have been major advances in the field of nanoscience and nanotechnology. Many applications have sprouted from these fields of research. It is essential, given the scale of the materials, to attain accurate, valid and reproducible measurements. Material properties have shown to be a function of their size and composition. Physiochemical properties of the nanomaterials can significantly alter material behavior compared to bulk counterparts. For example, metal oxide nanoparticles have found broad applications ranging from photo-catalysis to antibacterial agents. In our study, we synthesized CuO nanoparticles using well established sol-gel based methods with varying levels of Ni doping. However, upon analysis of measured infrared data, we discovered the presence of quasi-periodic (QP processes. Such processes have previously been reported to be tightly associated with measurement memory effects. We were able to detect the desired QP process in these measurements from three highly accurate repetitive experiments performed on each Ni (1-7% doped CuO sample. In other words, successive measurements performed in a rather short period of time remember each other at least inside a group of neighboring measurements.