FTIR spectroscopy

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Species-level determination of closely related araucarian resins using FTIR spectroscopy and its implications for the provenance of New Zealand amber

Species-level determination of closely related araucarian resins using FTIR spectroscopy and its implications for the provenance of New Zealand amber

This is the first study to apply FTIR spectroscopy to resins produced across closely related members of the Araucariaceae from Agathis and Araucaria plants growing in New Zealand and New Caledonia, and Wollemia from Australia (but grown in Germany). FTIR spectra of resins sampled across the Araucariaceae show unexpected variation, despite the small sample size: environmental variation could be a reason for the variability, but the spectra also show that the species’ resins are similar in chemical composition. When the resin FTIR spectra are compared with a Miocene New Zealand amber sample, a clear relationship is supported showing that the amber is indeed a fossilized Araucariaceae plant resin, but a contradiction appears since the amber has some features of a (relatively) immature fossil resin, particularly when compared to other fossil resins of the same age from New Zealand, perhaps indicating differences in diagenetic histories.
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Water vapour profiles by ground-based FTIR spectroscopy: study for an optimised retrieval and its validation

Water vapour profiles by ground-based FTIR spectroscopy: study for an optimised retrieval and its validation

As for the smoothing error, the random and systematic errors caused by parameter uncertainties are separated by means of least squares fits. Therefore, the retrievals of spectra simu- lated with correct parameters are correlated to the retrievals of spectra simulated with erroneous parameters. In this sub- section, errors due to measurement noise, uncertainties in so- lar angle, instrumental line shape (ILS: modulation efficiency and phase error Hase et al., 1999), temperature profile, and spectroscopic parameters (line intensity and pressure broad- ening coefficient) are estimated. The assumed parameter un- certainties are listed in Table 1. Two sources are consid- ered as errors in the temperature profile: first, the measure- ment uncertainty of the sonde, which is assumed to be 0.5 K throughout the whole troposphere and to have no interlevel correlations. Second, the temporal differences between the FTIR and the sonde’s temperature measurements, which are estimated to be 1.5 K at the surface and 0.5 K in the rest of the troposphere, with 5 km correlation length for the inter- level correlations.
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ATR-FTIR Spectroscopy for the Assessment of Biochemical Changes in Skin Due to Cutaneous Squamous Cell Carcinoma

ATR-FTIR Spectroscopy for the Assessment of Biochemical Changes in Skin Due to Cutaneous Squamous Cell Carcinoma

FTIR spectra can be acquired mainly in three different experimental configurations: transmission, reflection-absorption (transflection) or attenuated total reflection (ATR) [9]. The first one operates by transmitting IR radiation through sample-substrate, whereas in transflection the radiation interacts with sample and is back reflected off by the substrate [9]. Finally, on the ATR mode the sample is placed on a crystal with refractive index higher than sample, inducing total internal reflection of incident radiation, which is attenuated and penetrates into the sample as an evanescent wave [9,10].
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Extraction and Biochemical Characterization of Sulphated Glycosaminoglycans from Chicken Keel Cartilage

Extraction and Biochemical Characterization of Sulphated Glycosaminoglycans from Chicken Keel Cartilage

Qualitative analysis: GAGs in extracted semi-purified polysaccharides samples (n=3) was identified by FTIR spectroscopy technique using potassium bromide pellet and by comparing with standard CS, major component of total GAGs. Characteristic peaks of CS (standard) and samples extracted from chicken keel cartilages at mid infra red region at wavelength of 400 – 4000cm -1 are presented at Table 1. Characteristic Peak of C-O-S was observed at 856cm -1 in standard CS and same was recorded in extracted samples at 853 and 854cm -1 by FTIR spectroscopy. Spectra
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The effect of UV radiation on DNA in the presence of

The effect of UV radiation on DNA in the presence of

When designing drugs to treat diseases like cancer, which is characterized by an abnor- mal cellular growth, targeting the DNA seems logical in order to regulate cell functions. One possible way is to find molecules that are able to intercalate with DNA, and that in the presence of UV radiation will induce specific DNA lesions. These lesions could affect processes such as DNA transcription and replication, contributing to the non-proliferation of cancer cells. On this dissertation the influence of the intercalator 1,10-phenanthroline (Phen) on DNA degradation was analyzed in the presence of UV radiation, 254 nm. The damages caused by UV radiation were studied by vacuum ultraviolet (VUV), ultraviolet-visible (UV-Vis), and Fourier transform infrared (FTIR) spectroscopy. The obtained results showed that the presence of water is essen- tial in order to observe the effect of UV radiation. Both DNA and Phen were degraded when exposed to UV radiation. Through FTIR characterization it was possible to conclude that de- spite the fact that Phen had a degrading effect on some DNA components, it generally had a protective effect on most of the DNA components.
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J. Braz. Chem. Soc.  vol.24 número4

J. Braz. Chem. Soc. vol.24 número4

Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) are the most commonly used thermal techniques in drug-excipient and drug-drug compatibility assessments. Fourier-transform infrared (FTIR) spectroscopy is another approach used in compatibility tests based on the hypothesis that some functional groups change during drug- excipient and drug-drug interactions. 16-18 Other techniques,

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Cerium doped hydroxyapatite nanoparticles synthesized by coprecipitation method

Cerium doped hydroxyapatite nanoparticles synthesized by coprecipitation method

Department of Science and Engineering of Oxide Materials and Nanomaterials, 1–7 Polizu Street, P. O. Box 12–134, 011061 Bucharest, Romania (Received 24 August, revised 20 December, accepted 25 December 2015) Abstract: The present work reports a simple adapted co-precipitation method for the synthesis of stable Ce-substituted Ca hydroxyapatite (HAp) nano- particles. The structural and morphological properties of the Ce-doped hydro- xyapatite (Ce:HAp) were characterized by X-ray diffraction (XRD), trans- mission electron microscopy (TEM), scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDAX). The optical properties of the Ce- doped hydroxyapatite were also investigated using Fourier transform infrared (FTIR) spectroscopy, Fourier transform Raman spectroscopy and photolumine- scence analysis. The results of the XRD studies revealed the progressive inc- rease in the a- and c-axes with increasing Ce concentration. In the FTIR studies of Ce:HAp powders, a structure similar to that of hydroxyapatite was observed. The IR and Raman wavenumbers and the peak strengths of the bands asso- ciated with the P–O and O–H bonds decreased progressively with increasing Ce concentration. All the emission maxima could be attributed to 5d–4f tran- sitions of the Ce ions. The displacements of the maximum emission bands with increasing Cerium in the samples were in agreement with the results obtained by XRD studies. The Ce:HAp samples with x Ce = 0.03 and 0.05 exhibited
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Evaluation of polybutadiene rubbers using FTIR spectra

Evaluation of polybutadiene rubbers using FTIR spectra

In Figure 1 the FTIR Spectroscopy spectra for polybutadiene samples are shown for different absorbed doses of gamma radiation. The peaks are shown with their respectively wave numbers. The polybutadiene samples present characteristic absorptions from CH2 vibration on 1500-1400 cm -1 ; CH2 stretching on 1300-1200 cm -1 and also CH2 deformation on 1450-1340 cm -1 [10].

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Braz. J. Chem. Eng.  vol.25 número2

Braz. J. Chem. Eng. vol.25 número2

Abstract - Cellulose acetate-based molecularly imprinted polymeric membranes were prepared using vanillin as template molecule. The microscopic structure of the resultant polymeric membranes was characterized by SEM and FTIR spectroscopy, and the selective binding properties and separation capacity of the membranes for vanillin and o-vanillin were tested with binding experiments and separate experiments, respectively. The results showed that the vanillin-imprinted polymeric membranes displayed higher binding and separation capacity for vanillin in comparison with the non-imprinted polymeric membranes; the maximum binding amount Q max for vanillin is 387.3 µmol/g and the selectivity factor is 3.82 for vanillin/o-vanillin. In addition,
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Magnetic Amphiphilic Composites Based on Carbon Nanotubes and Nanofibers Grown on an Inorganic Matrix: Effect on Water-Oil Interfaces

Magnetic Amphiphilic Composites Based on Carbon Nanotubes and Nanofibers Grown on an Inorganic Matrix: Effect on Water-Oil Interfaces

New magnetic amphiphilic composites were prepared by the catalytic carbon vapor deposition (CVD) growth of carbon nanotubes and nanofibers using ethanol as carbon source and red mud waste (RM, a by-product of the Bayer process of alumina production) as catalyst and support. Temperature-programmed CVD (TPCVD), analyses by X-ray diffractometry (XRD), Mössbauer spectroscopy, energy dispersive X-ray spectroscopy (EDS), Raman spectroscopy, thermogravimetry (TG/DTA), elemental analysis (CHN), superficial area determination (BET), scanning (SEM) and transmission (TEM) electron microscopies and magnetic measurements showed that ethanol reduces the iron ions in the red mud to form magnetic phases, e.g., Fe 3 O 4 and Fe
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Polímeros  vol.7 número1

Polímeros vol.7 número1

R Resumo: esumo: esumo: esumo: esumo: A distribuição dos isômeros configuracionais de polióis PBLH utilizados na fabricação de propelentes foi determinada por FTIR empregando-se a técnica de análise em solução e o método desenvolvido neste trabalho, envolvendo análise por filme líquido. Os resultados obtidos são concordantes entre si e com os fornecidos por análise 1 H NMR.

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J. Braz. Chem. Soc.  vol.21 número12

J. Braz. Chem. Soc. vol.21 número12

New magnetic amphiphilic composites were prepared by the catalytic carbon vapor deposition (CVD) growth of carbon nanotubes and nanoibers using ethanol as carbon source and red mud waste (RM, a by-product of the Bayer process of alumina production) as catalyst and support. Temperature-programmed CVD (TPCVD), analyses by X-ray diffractometry (XRD), Mössbauer spectroscopy, energy dispersive X-ray spectroscopy (EDS), Raman spectroscopy, thermogravimetry (TG/DTA), elemental analysis (CHN), supericial area determination (BET), scanning (SEM) and transmission (TEM) electron microscopies and magnetic measurements showed that ethanol reduces the iron ions in the red mud to form magnetic phases, e.g., Fe 3 O 4 and Fe
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Sphingolipids of the mycopathogen Sporothrix schenckii: identification of a glycosylinositol phosphorylceramide with novel core GlcNH(2)alpha 1 -> 2Ins motif

Sphingolipids of the mycopathogen Sporothrix schenckii: identification of a glycosylinositol phosphorylceramide with novel core GlcNH(2)alpha 1 -> 2Ins motif

Abbreviations : NMR, nuclear magnetic resonance; COSY, correla- tion spectroscopy ; TOCSY, total correlation spectroscopy; NOESY, nuclear Overhauser e¡ect spectroscopy; HPLC, high performance liq- uid chromatography; HPTLC, high performance thin layer chroma- tography; GC, gas chromatography; ESI, electrospray ionization; MS, mass spectrometry ; CID, collision-induced decomposition; DMSO, dimethyl sulfoxide; TMS, trimethylsilyl ; FAME, fatty acid methyl ester

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Rev. Esc. Minas  vol.64 número1

Rev. Esc. Minas vol.64 número1

As camadas de fosfato do tipo hopeíta, nas quais o zinco é parcialmente substi- tuído por outros metais, como manganês e níquel, são de grande interesse para a in- dústria automotiva e de eletrodomésticos. Essas indústrias utilizam aços galvanizados, fosfatizados e pintados com eletropintura cataforética. Os fosfatos de zinco modii- cados com manganês e níquel são isomorfos com a hopeíta, e de difícil identiicação usando-se a técnica de difração de raios X. Nesse trabalho, as camadas de conversão de fosfato foram identiicadas usando-se a espectroscopia no infravermelho por trans- formada de Fourier (FTIR).
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Braz. oral res.  vol.25 número3

Braz. oral res. vol.25 número3

tional methods, such as infrared spectroscopy (FTIR) and Raman spectroscopy (FT-Raman), offers a direct approach to quantify the ratio of monomers’ con- version into polymers; this quantiication is accom- plished by assessing the speciic band positions and by comparing the residual unpolymerized aliphatic C=C stretching band at 1640  cm −1 to the aromatic C=C stretching band at 1610 cm −1 . 8,9,16 Thus, the ra-

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Application of functional data analysis and FTIR-ATR spectroscopy to discriminate wine spirits ageing technologies

Application of functional data analysis and FTIR-ATR spectroscopy to discriminate wine spirits ageing technologies

First, the different groups based on the ageing technology and kind of wood (AC, AL, TC, and TL) were tested. The contrast is different for each ageing time (18 months, 12 months, and 6 months). With an 18-month period, the hypothesis of similarity between all groups is rejected in all areas of the whole curve and from both points of view (Table 4). The samples of wine spirits aged by the alternative technology, on average, have higher absorbance units than the aged by the traditional one. Within the alternative technology, the wine spirit aged in oak wood always showed higher absorbance units than the one aged in chestnut wood (Figure 3). With an ageing period of 12 months, the similarity hypothesis is also rejected in all areas by the two analyses (Table 4). Even so, in this case, the differences between alternative and traditional ageing technologies are small. The spectrometric curves can hardly be differentiated in the functional part of Figure 4, and the p-values Figure 2. Fourier transform infrared spectroscopy–Attenuated Total Reflection (FTIR-ATR) absorbance spectra of wine spirit samples.
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INFLUENCE OF REACTION TIME ON THE STRUCTURE OF POLYANILINE SYNTHESIZED ON A PRE-PILOT SCALE

INFLUENCE OF REACTION TIME ON THE STRUCTURE OF POLYANILINE SYNTHESIZED ON A PRE-PILOT SCALE

In this study, the synthesis of PAni was carried out on a pre-pilot scale, with different times of reaction, keeping the other parameters of synthesis constant. Through spec- trometric analysis by Fourier Transform Infrared (FTIR), Raman spectroscopy and UV-Visible, the quantification of the degree of oxidation and yield seeks to determine the changes that occur in the structure of PAni during the chemical synthesis, following the addition of oxidant until 2 h after the end of this addition, aiming at contributing to the optimization of this synthesis process.

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APROVEITAMENTO DE RESÍDUOS AGROINDUSTRIAIS: CARACTERIZAÇÃO FÍSICO – QUÍMICA E PRODUÇÃO DE CARVÃO PARA ENERGIA

APROVEITAMENTO DE RESÍDUOS AGROINDUSTRIAIS: CARACTERIZAÇÃO FÍSICO – QUÍMICA E PRODUÇÃO DE CARVÃO PARA ENERGIA

El carbón vegetal tiene gran participación en el mercado brasileño y es consumido actualmente en su mayoría por la industria de hierro fundido. Aunque su producción tradicional es a partir de madera, otras fuentes como la biomasa pueden ser utilizadas como materia prima. El objetivo de este trabajo fue producir carbón vegetal a partir de cáscara de coco, tuza de maíz y corteza de eucalipto, como alternativa para sustituir el carbón vegetal producido a partir de madera nativa y utilizado como fuente de energía en la industria. Se utilizaron cinco temperaturas de pirolisis: 300, 350, 400, 450 y 500°C. Todos los materiales se caracterizaron mediante análisis próximo, poder calorífico superior (PCS), composición química, termogravimetria (TG), termogravimetria derivada (DTG) y espectroscopia en el infrarrojo (FTIR). Las muestras después de la pirolisis se compararon con la biomasa in natura para evaluar los cambios en las características del combustible. En los resultados de análisis próximo se observó, para todos los tipos de biomasa, un aumento estadísticamente significativo en el contenido de carbono fijo, y consecuente disminución en el contenido de materiales volátiles, con el aumento de la temperatura. El aumento en el PCS de los carbones probablemente se debió al hecho del contenido de carbono fijo haber aumentado después de las pirolisis. Los resultados de composición química y rendimiento gravimétrico (RG) mostraron que cuanto mayor el contenido de lignina y celulosa en la biomasa in natura, mayor fue el RG de los carbones para todas las temperaturas utilizadas. Las temperaturas de 300-350°C fueron suficientes para producir carbón vegetal con RG superior al 34% con posible aplicación residencial. La producción de carbón vegetal con posible uso industrial (metalúrgico) necesitó temperaturas superiores a los 400°C dependiendo del tipo de biomasa, pero obtuvieron RG inferiores al 30%. Se comprobó que los carbones producidos a 450 y 500°C tuvieron el mayor PCS pero con bajo RG y rendimiento energético (RE). Las curvas de DTG y FTIR permitieron comprobar la degradación de la hemicelulosa y la celulosa en los carbones producidos.
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Quím. Nova  vol.35 número7

Quím. Nova vol.35 número7

Since ionic content is one of the most important parameters that affect swelling, knowledge of the real acrylamide/acrylate ratio in these hydrogels is a subject of interest. The aim of the present work was to report a procedure to determine acrylate/acrylamide ratio in poly(sodium acrylate-co-acrylamide) hydrogels, based on the widely used spectroscopic technique of FTIR.

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PROTEIN IDENTIFICATION USING FOURIER TRANFORM INFRARED (FTIR)

PROTEIN IDENTIFICATION USING FOURIER TRANFORM INFRARED (FTIR)

Table 1 shows types of amide in protein samples. Amide is the easiest protein group marker to be identified in protein samples. Therefore, to determine protein content of a sample, the easiest way is to detect the amide in it. Various types of amide show specific functional groups in different protein samples. All amides should have been identified by FTIR due to its specific functional groups. However, overlapping or weakening absorbance of same functional groups could happen so that only few amides FTIR could detect as shown in Table 3.

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