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Sample records for reflectance-fourier transform infrared

  1. Preliminary Method for Direct Quantification of Colistin Methanesulfonate by Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy

    PubMed Central

    Niece, Krista L.

    2015-01-01

    Colistin use has increased in response to the advent of infections caused by multidrug-resistant organisms. It is administered parenterally as an inactive prodrug, colistin methanesulfonate (CMS). Various formulations of CMS and labeling conventions can lead to confusion about colistin dosing, and questions remain about the pharmacokinetics of CMS. Since CMS does not have strong UV absorbance, current methods employ a laborious process of chemical conversion to colistin followed by precolumn derivatization to detect formed colistin by high-performance liquid chromatography. Here, we report a method for direct quantification of colistin methanesulfonate by attenuated total reflectance Fourier transform infrared spectroscopy (ATR FTIR). PMID:26124160

  2. Preliminary method for direct quantification of colistin methanesulfonate by attenuated total reflectance Fourier transform infrared spectroscopy.

    PubMed

    Niece, Krista L; Akers, Kevin S

    2015-09-01

    Colistin use has increased in response to the advent of infections caused by multidrug-resistant organisms. It is administered parenterally as an inactive prodrug, colistin methanesulfonate (CMS). Various formulations of CMS and labeling conventions can lead to confusion about colistin dosing, and questions remain about the pharmacokinetics of CMS. Since CMS does not have strong UV absorbance, current methods employ a laborious process of chemical conversion to colistin followed by precolumn derivatization to detect formed colistin by high-performance liquid chromatography. Here, we report a method for direct quantification of colistin methanesulfonate by attenuated total reflectance Fourier transform infrared spectroscopy (ATR FTIR).

  3. Estimation of blood alcohol concentration by horizontal attenuated total reflectance-Fourier transform infrared spectroscopy.

    PubMed

    Sharma, Kakali; Sharma, Shiba P; Lahiri, Sujit C

    2010-06-01

    Numerous methods like distillation followed by iodometric titrations, gas chromatograph (GC)-flame ionization detector, gas chromatograph-mass spectrophotometer, GC-Headspace, Breath analyzer, and biosensors including alcohol dehydrogenase (enzymatic) have been used to determine blood alcohol concentration (BAC). In the present study, horizontal attenuated total reflectance-Fourier transform infrared spectroscopy had been used to determine BAC in whole blood. The asymmetric stretching frequency of C-C-O group of ethanol in water (1,045 cm(-1)) had been used to calculate BAC using Beer's Law. A seven-point calibration curve of ethanol was drawn in the concentration range 24-790 mg dL(-1). The curve showed good linearity over the concentration range used (r(2)=0.999, standard deviation=0.0023). The method is accurate, reproducible, rapid, simple, and nondestructive in nature. PMID:20541351

  4. Attenuated total reflectance Fourier-transform infrared spectroscopy of carboxylic acids adsorbed onto mineral surfaces

    NASA Astrophysics Data System (ADS)

    Kubicki, J. D.; Schroeter, L. M.; Itoh, M. J.; Nguyen, B. N.; Apitz, S. E.

    1999-09-01

    A suite of naturally-occurring carboxylic acids (acetic, oxalic, citric, benzoic, salicylic and phthalic) and their corresponding sodium salts were adsorbed onto a set of common mineral substrates (quartz, albite, illite, kaolinite and montmorillonite) in batch slurry experiments. Solution pH's of approximately 3 and 6 were used to examine the effects of pH on sorption mechanisms. Attenuated total reflectance Fourier-transform infrared (ATR FTIR) spectroscopy was employed to obtain vibrational frequencies of the organic ligands on the mineral surfaces and in solution. UV/visible spectroscopy on supernatant solutions was also employed to confirm that adsorption from solution had taken place for benzoic, salicylic and phthalic acids. Molecular orbital calculations were used to model possible surface complexes and interpret the experimental spectra. In general, the tectosilicates, quartz and albite feldspar, did not chemisorb (i.e., strong, inner-sphere adsorption) the carboxylate anions in sufficient amounts to produce infrared spectra of the organics after rinsing in distilled water. The clays (illite, kaolinite and montmorillonite) each exhibited similar ATR FTIR spectra. However, the illite sample used in this study reacted to form strong surface and aqueous complexes with salicylic acid before being treated to remove free Fe-hydroxides. Chemisorption of carboxylic acids onto clays is shown to be limited without the presence of Fe-hydroxides within the clay matrix.

  5. Secondary cell wall development in cotton fibers as examined with attenuated total reflection Fourier transform infrared spectroscopy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cotton fibers harvested at 18, 20, 24, 28, 32, 36 and 40 days after flowering were examined using attenuated total reflection Fourier transform-infrared (ATR FT-IR) spectroscopy. The selected harvesting points coincide with secondary cell wall (SCW) development in the fibers. Progressive but moderat...

  6. Attenuated total reflectance Fourier transform infrared spectroscopy method to differentiate between normal and cancerous breast cells.

    PubMed

    Lane, Randy; See, Seong S

    2012-09-01

    Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) is used to find the structural differences between cancerous breast cells (MCF-7 line) and normal breast cells (MCF-12F line). Gold nanoparticles were prepared and the hydrodynamic diameter of the gold nanoparticles found to be 38.45 nm. The Gold nanoparticles were exposed to both MCF-7 and MCF-12F cells from lower to higher concentrations. Spectroscopic studies founds nanoparticles were within the cells, and increasing the nanoparticles concentration inside the cells also resulted in sharper IR peaks as a result of localized surface Plasmon resonance. Asymmetric and symmetric stretching and bending vibrations between phosphate, COO-, CH2 groups were found to give negative shifts in wavenumbers and a decrease in peak intensities when going from noncancerous to cancerous cells. Cellular proteins produced peak assignments at the 1542 and 1644 cm(-1) wavenumbers which were attributed to the amide I and amide II bands of the polypeptide bond of proteins. Significant changes were found in the peak intensities between the cell lines in the spectrum range from 2854-2956 cm(-1). Results show that the concentration range of gold nanoparticles used in this research showed no significant changes in cell viability in either cell line. Therefore, we believe ATR-FTIR and gold nanotechnology can be at the forefront of cancer diagnosis for some time to come.

  7. Attenuated total reflectance fourier transform infrared analysis of fly ash geopolymer gel aging.

    PubMed

    Rees, Catherine A; Provis, John L; Lukey, Grant C; van Deventer, Jannie S J

    2007-07-17

    Structural changes in fly ash geopolymers activated with different sodium hydroxide and silicate concentrations are investigated using attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy over a period of 200 days. A strong correlation is found between the concentration of silicate monomer in the activating solution and the position of the main Si-O-T stretching band in the FTIR spectrum, which gives an indication of the relative changes in the gel Si/Al ratio. The FTIR spectra of geopolymer samples with activating solution concentrations of up to 1.2 M SiO2 indicate that an Al-rich gel forms before the final gel composition is reached. The time required for the system to reach a steady gel composition depends on the silicate activating solution concentration and speciation. Geopolymers activated with solutions containing predominantly high-order silicate species rapidly reach a steady gel composition without first forming an Al-rich gel. A minimum silicate monomer concentration of approximately 0.6 M is required to shift the geopolymer synthesis mechanism from hydroxide activation to silicate activation. Silicate speciation in the activating solutions also affects zeolite formation and geopolymer microstructures, with a more homogeneous microstructure and less zeolite formation observed at a higher SiO2 content.

  8. [Attenuated total reflection-fourier transform infrared spectroscopic study of dried shark fin products].

    PubMed

    Han, Wan-qing; Luo, Hai-ying; Xian, Yan-ping; Luo, Dong-hui; Mu, Torng-na; Guo, Xin-dong

    2015-02-01

    Sixty-four pieces of shark fin dried products (including real, fake and artificial shark fin products) and real products coated with gelatin were rapidly and nondestructively analyzed by attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR). The characteristic of IR spectrograms among the above four kinds of samples were systematically studied and comparied, the results showed that the spectrograms of the same kind of samples were repeatable, and different kinds of shark fin products presented significant differences in the spectrograms, which mainly manifested as the specific absorption peaks of amido bonds in protein (1650, 1544 cm(-1)) and skeletal vibration in polysaccharide (1050 cm(-1)). The spectrograms of real shark fins were characterized by the strong absorption peaks of protein characteristic amide I and II absorbent (1650, 1544 cm(-1)) and relatively weak C--O--C vibration absorbent (1050 cm(-1)) owing to the high content of protein and relatively low level of polysaccharide. For fake shark fin products that were molded form by mixing together with the offcut of shark, collagen and other substances, the introduction of non-protein materials leaded to the weaker amido bonds absorbent than real products along with a 30 cm(-1) blue shift of amide I absorbent. Opposite to the real sample, the relatively strong absorption peak of polysaccharide (approximately 1047 cm(-1)) and barely existed amide absorbent were the key features of the spectrogram of artificial samples, which was synthersized by polysaccharide like sodium alginate. Real samples coated with gelatin, the peak strength of protein and polysaccharide were decreased simultaneously when the data collection was taken at the surface of sample, while the spectrogram presented no significant difference to real samples when the data was collected in the section. The results above indicated that by analyzing the characteristic of IR spectrograms and the value range of Apro

  9. Evaluation of various polyethylene as potential dosimeters by attenuated total reflectance-Fourier-transform infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Halperin, Fred; Collins, Greta; DiCicco, Michael; Logar, John

    2014-12-01

    Various types of polyethylene (PE) have been evaluated in the past for use as a potential dosimeter, chiefly via the formation of an unsaturated transvinylene (TV) double-bond resulting from exposure to ionizing radiation. The utilization of attenuated total reflectance Fourier-transform infrared (ATR-FTIR) spectroscopy in characterizing TV formation in irradiated PE for a potential dosimeter has yet to be fully developed. In this initial investigation, various PE films/sheets were exposed to ionizing radiation in a high-energy 5 megaelectron volt (MeV) electron beam accelerator in the 10-500 kilogray (kGy) dose range, followed by ATR-FTIR analysis of TV peak formation at the 965 cm-1 wavenumber. There was an upward trend in TV formation for low-density polyethylene (LDPE) films and high-density polyethylene (HDPE) sheets as a function of absorbed dose in the 10-50 kGy dose range, however, the TV response could not be equated to a specific absorbed dose. LDPE film displayed a downward trend from 50 kGy to 250 kGy and then scattering up to 500 kGy; HDPE sheets demonstrated an upward trend in TV formation up to 500 kGy. For ultra-high molecular weight polyethylene (UHMWPE) sheets irradiated up to 150 kGy, TV response was equivalent to non-irradiated UHMWPE, and a minimal upward trend was observed for 200 kGy to 500 kGy. The scatter of the data for the irradiated PE films/sheets is such that the TV response could not be equated to a specific absorbed dose. A better correlation of the post-irradiation TV response to absorbed dose may be attained through a better understanding of variables.

  10. Geographical differentiation of dried lentil seed (Lens culinaris) samples using diffuse reflectance Fourier transform infrared spectroscopy (DRIFTS) and discriminant analysis.

    PubMed

    Kouvoutsakis, G; Mitsi, C; Tarantilis, P A; Polissiou, M G; Pappas, C S

    2014-02-15

    Diffuse reflectance Fourier transform infrared spectroscopy (DRIFTS) and discriminant analysis were used for the geographical differentiation of dried lentil seed (Lens culinaris) samples. Specifically, 18 Greek samples and nine samples imported from other countries were distinguished using the 2250-1720 and 1275-955 cm⁻¹ spectral regions. The differentiation is complete. The combination of DRIFTS and discriminant analysis enables simple, rapid, cheap and accurate differentiation of commercial lentil seeds in terms of geographical origin.

  11. Use of attenuated total reflectance Fourier transform infrared spectroscopy to identify microbial metabolic products on carbonate mineral surfaces.

    PubMed

    Bullen, Heather A; Oehrle, Stuart A; Bennett, Ariel F; Taylor, Nicholas M; Barton, Hazel A

    2008-07-01

    This paper demonstrates the use of attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy to detect microbial metabolic products on carbonate mineral surfaces. By creating an ATR-FTIR spectral database for specific organic acids using ATR-FTIR spectroscopy we were able to distinguish metabolic acids on calcite surfaces following Escherichia coli growth. The production of these acids by E. coli was verified using high-performance liquid chromatography with refractive index detection. The development of this technique has allowed us to identify microbial metabolic products on carbonate surfaces in nutrient-limited cave environments.

  12. Use of Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy To Identify Microbial Metabolic Products on Carbonate Mineral Surfaces▿ †

    PubMed Central

    Bullen, Heather A.; Oehrle, Stuart A.; Bennett, Ariel F.; Taylor, Nicholas M.; Barton, Hazel A.

    2008-01-01

    This paper demonstrates the use of attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy to detect microbial metabolic products on carbonate mineral surfaces. By creating an ATR-FTIR spectral database for specific organic acids using ATR-FTIR spectroscopy we were able to distinguish metabolic acids on calcite surfaces following Escherichia coli growth. The production of these acids by E. coli was verified using high-performance liquid chromatography with refractive index detection. The development of this technique has allowed us to identify microbial metabolic products on carbonate surfaces in nutrient-limited cave environments. PMID:18502924

  13. Use of attenuated total reflection-Fourier transform infrared spectroscopy to measure collagen degradation in historical parchments.

    PubMed

    Gonzalez, Lee; Wess, Tim

    2008-10-01

    Developing a noninvasive method to assess the degraded state of historical parchments is essential to providing the best possible care for these documents. The conformational changes observed when collagen molecules, the primary constituent of parchment, unfold have been analyzed using attenuated total reflection-Fourier transform infrared (ATR-FT-IR) spectroscopy and the nanoscopic structural changes have been analyzed using X-ray diffraction (XRD). The relationship between the results obtained from these techniques was studied using principal component analysis, where correlation was found. The extent of gelatinization of historical parchments has been assessed using ATR-FT-IR and XRD and the frequency shifts observed as collagen degrades into gelatin have been reported. These results indicate that collagen degradation can be measured noninvasively in parchment and demonstrate the utility of ATR-FT-IR spectroscopy as a method to investigate historical documents.

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

    PubMed

    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. PMID:26896150

  15. New diagnostic method for monitoring plasma reactor walls: Multiple total internal reflection Fourier transform infrared surface probe

    NASA Astrophysics Data System (ADS)

    Godfrey, Anna R.; Ullal, Saurabh J.; Braly, Linda B.; Edelberg, Erik A.; Vahedi, Vahid; Aydil, Eray S.

    2001-08-01

    Films and adsorbates that deposit on reactor walls during plasma etching and deposition affect the discharge properties such as the charged particle and reactive radical concentrations. A systematic study of this plasma-wall interaction is made difficult by a lack of diagnostic methods that enable one to monitor the chemical nature of the reactor wall surface. A new diagnostic technique based on multiple total internal reflection Fourier transform infrared (MTIR-FTIR) spectroscopy was developed to monitor films and adsorbates on plasma etching and deposition reactor walls with monolayer sensitivity. Applications of this MTIR-FTIR probe are demonstrated. Specifically, we use this probe to (i) detect etch products and films that deposit on the reactor walls during Cl2 plasma etching of Si, (ii) determine the efficacy of a SF6 plasma to clean films deposited on reactor walls during Cl2/O2 etching of Si, and (iii) monitor wafer-to-wafer etching reproducibility.

  16. Characterization of historic silk by polarized attenuated total reflectance Fourier transform infrared spectroscopy for informed conservation.

    PubMed

    Garside, Paul; Lahlil, Sophia; Wyeth, Paul

    2005-10-01

    When assessing historic textiles and considering appropriate conservation, display, and storage strategies, characterizing the physical condition of the textiles is essential. Our work has concentrated on developing nondestructive or micro-destructive methodologies that will permit this. Previously, we have demonstrated a correlation between the physical deterioration of unweighted and "pink" tin (IV) chloride weighted silk and certain measurable spectroscopic and chromatographic signatures, derived from polarized Fourier transform infrared attenuated total reflectance (FTIR-ATR) spectroscopy (Pol-ATR) and high-performance liquid chromatography (HPLC) microsampling analyses. The application of the Pol-ATR technique to aged silk characterization has now been extended to include a more comprehensive range of weighting methods and aging regimes. This was intended to replicate the full spectrum of states of deterioration observed in silk textiles, from pristine to heavily degraded. Breaking strength was employed as a measure of the physical integrity of the fibers, and, as expected, decreased with aging. An orientational crystallinity parameter, reflecting the microstructural ordering of the fibroin polymer within the fibers, was derived from the Pol-ATR spectra. A good correlation was observed between the breaking strength of the variety of fibers and this parameter. This suggests that the physical state of historic silk fabrics might be adequately characterized for conservation purposes by such indirect micromethodology.

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

    PubMed

    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. PMID:27412186

  18. Application of attenuated total reflectance Fourier transform infrared spectroscopy in the mineralogical study of a landslide area, Hungary

    NASA Astrophysics Data System (ADS)

    Udvardi, Beatrix; Kovács, István János; Kónya, Péter; Földvári, Mária; Füri, Judit; Budai, Ferenc; Falus, György; Fancsik, Tamás; Szabó, Csaba; Szalai, Zoltán; Mihály, Judith

    2014-11-01

    This study demonstrates that the unpolarized attenuated total reflectance Fourier transform infrared spectroscopy (ATR FTIR) is a practical and quick tool to distinguish different types of sediments in landslide-affected areas, and potentially other types of physical environments too. Identification and quantification of minerals by ATR FTIR is implemented on a set of powdered natural sediments from a loess landslide (Kulcs, Hungary). A protocol including sample preparation, analytical conditions and evaluation of sediment ATR spectra is outlined in order to identify and estimate major minerals in sediments. The comparison of the defined FTIR parameters against qualitative and quantitative results of X-ray diffraction and thermal analysis was used to validate the use of ATR FTIR spectroscopy for the considered sediments. The infrared band areas and their ratios (water/carbonates; silicates/carbonates; kaolinite) appear to be the most sensitive parameters to identify strongly weathered sediments such as paleosols and red clays which most likely facilitate sliding and could form sliding zones. The effect of grain size and orientation of anisotropic minerals on the wave number and intensity of some major absorption bands is also discussed.

  19. Analysis of captan on nitrile glove surfaces using a portable attenuated total reflection fourier transform infrared spectrometer.

    PubMed

    Phalen, R N; Que Hee, Shane S

    2005-06-01

    This study developed a method to produce uniform captan surface films on a disposable nitrile glove for quantitation with a portable attenuated total reflection Fourier transform infrared (ATR-FTIR) spectrometer. A permeation test was performed using aqueous captan formulation. Uniform captan surface films were produced using solvent casting with 2-propanol and a 25 mm filter holder connected to a vacuum manifold to control solvent evaporation. The coefficient of variation of the reflectance at 1735 +/- 5 cm(-1) was minimized by selection of the optimum solvent volume, airflow rate, and evaporation time. At room temperature, the lower to upper quantifiable limits were 0.31-20.7 microg/cm2 (r = 0.9967; p < or = 0.05) for the outer glove surface and 0.55-17.5 microg/cm2 (r = 0.9409; p < or = 0.05) for the inner surface. Relative humidity and temperature did not affect the uncoated gloves at the wavelength of captan analysis. Glove screening using ATR-FTIR was necessary as a control for between-glove variation. Captan permeation, after 8 hours exposure to an aqueous concentration of 217 mg/mL of Captan 50-WP, was detected at 0.8 +/- 0.3 microg/cm2 on the inner glove surface. ATR-FTIR can detect captan permeation and can determine the protectiveness of this glove in the field.

  20. Quantitative determination of competitive molecular adsorption on gold nanoparticles using attenuated total reflectance-Fourier transform infrared spectroscopy.

    PubMed

    Tsai, De-Hao; Davila-Morris, Melissa; DelRio, Frank W; Guha, Suvajyoti; Zachariah, Michael R; Hackley, Vincent A

    2011-08-01

    Surface-sensitive quantitative studies of competitive molecular adsorption on nanoparticles were conducted using a modified attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy method. Adsorption isotherms for thiolated poly(ethylene glycol) (SH-PEG) on gold nanoparticles (AuNPs) as a function of molecular mass (1, 5, and 20 kDa) were characterized. We find that surface density of SH-PEG on AuNPs is inversely proportional to the molecular mass (M(m)). Equilibrium binding constants for SH-PEG, obtained using the Langmuir adsorption model, show the binding affinity for SH-PEG is proportional to M(m). Simultaneous competitive adsorption between mercaptopropionic acid (MPA) and 5 kDa SH-PEG (SH-PEG5K) was investigated, and we find that MPA concentration is the dominant factor influencing the surface density of both SH-PEG5K and MPA, whereas the concentration of SH-PEG5K affects only SH-PEG5K surface density. Electrospray differential mobility analysis (ES-DMA) was employed as an orthogonal characterization technique. ES-DMA results are consistent with the results obtained by ATR-FTIR, confirming our conclusions about the adsorption process in this system. Ligand displacement competitive adsorption, where the displacing molecular species is added after completion of the ligand surface binding, was also interrogated by ATR-FTIR. Results indicate that for SH-PEG increasing M(m) yields greater stability on AuNPs when measured against displacement by bovine serum albumin (BSA) as a model serum protein. In addition, the binding affinity of BSA to AuNPs is inhibited for SH-PEG conjugated AuNPs, an effect that is enhanced at higher SH-PEG M(m) values.

  1. Attenuated total reflection fourier transform infrared spectroscopy towards disclosing mechanism of bacterial adhesion on thermally stabilized titanium nano-interfaces.

    PubMed

    Gopal, Judy; Chun, Sechul; Doble, Mukesh

    2016-08-01

    Titanium is widely used as medical implant material and as condenser material in the nuclear industry where its integrity is questioned due to its susceptibility to bacterial adhesion. A systematic investigation on the influence of thermally (50-800 °C) stabilized titanium (TS-Ti) nano oxide towards bacterial adhesion was carried out. The results showed that below 350 °C significant bacterio-phobicity was observed, while above 500 °C significant affinity towards bacterial cells was recorded. Conventional characterization tools such as HR-TEM and XRD did not provide much insight on the changes occurring on the oxide film with heat treatment, however, attenuated total reflection fourier transform infrared spectroscopy (ATR-FTIR) of the surface showed significant changes in the spectral pattern as a function of increasing heat treatment. It was observed that elevated OH, N-H and C=O groups and rutile titania on the TS-Ti oxide films led to higher affinity for bacterial adhesion. On the other hand low temperature TS-Ti nanooxide films (<350 °C) showed high C-H groups and decreased OH groups on their surface, which possibly contributed towards their bacterio-phobicity. The TS-Ti nanooxide film grown at 50 °C was observed to be the most efficient anti-bacterial adhesion interface, while the 800 °C interface was the one showing highest affinity towards bacterial adhesion. This study confirms the successful application of ATR-FTIR technique for nano-oxide film characterization and towards understanding the variations in bacterial interaction of such nano interfaces. PMID:27412653

  2. Attenuated Total Reflection Fourier Transform Infrared Spectroscopy (ATR FT-IR) Applied to Study the Distribution of Ink Components in Printed Newspapers.

    PubMed

    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. PMID:27129363

  3. Attenuated Total Reflection Fourier Transform Infrared Spectroscopy (ATR FT-IR) Applied to Study the Distribution of Ink Components in Printed Newspapers.

    PubMed

    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.

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

    PubMed

    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.

  5. Historical perspective and modern applications of Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy (ATR-FTIR).

    PubMed

    Blum, Marc-Michael; John, Harald

    2012-01-01

    Vibrational spectroscopy has a long history as an important spectroscopic method in chemical and pharmaceutical analysis. Instrumentation for infrared (IR) spectroscopy was revolutionized by the introduction of Fourier Transform Infrared (FTIR) spectrometers. In addition, easier sampling combined with better sample-to-sample reproducibility and user-to-user spectral variation became available with attenuated total reflectance (ATR) probes and their application for in situ IR spectroscopy. These innovations allow many new applications in chemical and pharmaceutical analysis, such as the use of IR spectroscopy in Process Analytical Chemistry (PAC), the quantitation of drugs in complex matrix formulations, the analysis of protein binding and function and in combination with IR microscopy to the emergence of IR imaging technologies. The use of ATR-FTIR instruments in forensics and first response to 'white powder' incidents is also discussed. A short overview is given in this perspective article with the aim to renew and intensify interest in IR spectroscopy.

  6. Classification of pumpkin seed oils according to their species and genetic variety by attenuated total reflection Fourier-transform infrared spectroscopy.

    PubMed

    Saucedo-Hernández, Yanelis; Lerma-García, María Jesús; Herrero-Martínez, José Manuel; Ramis-Ramos, Guillermo; Jorge-Rodríguez, Elisa; Simí-Alfonso, Ernesto F

    2011-04-27

    Attenuated total reflection Fourier-transform infrared spectroscopy (ATR-FTIR), followed by multivariate treatment of the spectral data, was used to classify seed oils of the genus Cucurbita (pumpkins) according to their species as C. maxima, C. pepo, and C. moschata. Also, C. moschata seed oils were classified according to their genetic variety as RG, Inivit C-88, and Inivit C-2000. Up to 23 wavelength regions were selected on the spectra, each region corresponding to a peak or shoulder. The normalized absorbance peak areas within these regions were used as predictors. Using linear discriminant analysis (LDA), an excellent resolution among all categories concerning both Cucurbita species and C. moschata varieties was achieved. The proposed method was straightforward and quick and can be easily implemented. Quality control of pumpkin seed oils is important because Cucurbita species and genetic variety are both related to the pharmaceutical properties of the oils.

  7. Using attenuated total reflection Fourier transform infrared spectroscopy (ATR FT-IR) to study the molecular conformation of parchment artifacts in different macroscopic states.

    PubMed

    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. Application of attenuated total reflectance Fourier transform infrared spectroscopy for determination of cefixime in oral pharmaceutical formulations

    NASA Astrophysics Data System (ADS)

    Kandhro, Aftab A.; Laghari, Abdul Hafeez; Mahesar, Sarfaraz A.; Saleem, Rubina; Nelofar, Aisha; Khan, Salman Tariq; Sherazi, S. T. H.

    2013-11-01

    A quick and reliable analytical method for the quantitative assessment of cefixime in orally administered pharmaceutical formulations is developed by using diamond cell attenuated total reflectance (ATR) Fourier transform infrared (FT-IR) spectroscopy as an easy procedure for quality control laboratories. The standards for calibration were prepared in aqueous medium ranging from 350 to 6000 mg/kg. The calibration model was developed based on partial least square (PLS) using finger print region of FT-IR spectrum in the range from 1485 to 887 cm-1. Excellent coefficient of determination (R2) was achieved as high as 0.99976 with root mean square error of 44.8 for calibration. The application of diamond cell (smart accessory) ATR FT-IR proves a reliable determination of cefixime in pharmaceutical formulations to assess the quality of the final product.

  9. Application of attenuated total reflectance Fourier transform infrared spectroscopy for determination of cefixime in oral pharmaceutical formulations.

    PubMed

    Kandhro, Aftab A; Laghari, Abdul Hafeez; Mahesar, Sarfaraz A; Saleem, Rubina; Nelofar, Aisha; Khan, Salman Tariq; Sherazi, S T H

    2013-11-01

    A quick and reliable analytical method for the quantitative assessment of cefixime in orally administered pharmaceutical formulations is developed by using diamond cell attenuated total reflectance (ATR) Fourier transform infrared (FT-IR) spectroscopy as an easy procedure for quality control laboratories. The standards for calibration were prepared in aqueous medium ranging from 350 to 6000mg/kg. The calibration model was developed based on partial least square (PLS) using finger print region of FT-IR spectrum in the range from 1485 to 887cm(-1). Excellent coefficient of determination (R(2)) was achieved as high as 0.99976 with root mean square error of 44.8 for calibration. The application of diamond cell (smart accessory) ATR FT-IR proves a reliable determination of cefixime in pharmaceutical formulations to assess the quality of the final product.

  10. Membrane molecule reorientation in an electric field recorded by attenuated total reflection Fourier-transform infrared spectroscopy.

    PubMed

    Le Saux, A; Ruysschaert, J M; Goormaghtigh, E

    2001-01-01

    Electric fields play an important role in the physiological function of macromolecules. Much is known about the role that electric fields play in biological systems, but membrane molecule structure and orientation induced by electric fields remain essentially unknown. In this paper, we present a polarized attenuated total reflection (ATR) experiment we designed to study the effect of electric fields on membrane molecule structure and orientation by Fourier-transform infrared (FTIR) spectroscopy. Two germanium crystals used as the internal reflection element for ATR-FTIR experiments were coated with a thin layer of polystyrene as insulator and used as electrodes to apply an electric field on an oriented stack of membranes made of dioleylphosphatidylcholine (DOPC) and melittin. This experimental set up allowed us for the first time to show fully reversible orientational changes in the lipid headgroups specifically induced by the electric potential difference.

  11. Membrane molecule reorientation in an electric field recorded by attenuated total reflection Fourier-transform infrared spectroscopy.

    PubMed Central

    Le Saux, A; Ruysschaert, J M; Goormaghtigh, E

    2001-01-01

    Electric fields play an important role in the physiological function of macromolecules. Much is known about the role that electric fields play in biological systems, but membrane molecule structure and orientation induced by electric fields remain essentially unknown. In this paper, we present a polarized attenuated total reflection (ATR) experiment we designed to study the effect of electric fields on membrane molecule structure and orientation by Fourier-transform infrared (FTIR) spectroscopy. Two germanium crystals used as the internal reflection element for ATR-FTIR experiments were coated with a thin layer of polystyrene as insulator and used as electrodes to apply an electric field on an oriented stack of membranes made of dioleylphosphatidylcholine (DOPC) and melittin. This experimental set up allowed us for the first time to show fully reversible orientational changes in the lipid headgroups specifically induced by the electric potential difference. PMID:11159405

  12. Detection and identification of explosive particles in fingerprints using attenuated total reflection-Fourier transform infrared spectromicroscopy.

    PubMed

    Mou, Yongyan; Rabalais, J Wayne

    2009-07-01

    The application of attenuated total reflection (ATR)-Fourier transform infrared (FTIR) spectromicroscopy for detection of explosive particles in fingerprints is described. The combined functions of ATR-FTIR spectromicroscopy are visual searching of particles in fingerprints and measuring the FTIR spectra of the particles. These functions make it possible to directly identify whether a suspect has handled explosives from the fingerprints alone. Particles in explosive contaminated fingerprints are either ingredients of the explosives, finger residues, or other foreign materials. These cannot normally be discriminated by their morphology alone. ATR-FTIR spectra can provide both particle morphology and composition. Fingerprints analyzed by ATR-FTIR can be used for further analysis and identification because of its non-destructive character. Fingerprints contaminated with three different types of explosives, or potential explosives, have been analyzed herein. An infrared spectral library was searched in order to identify the explosive residues. The acquired spectra are compared to those of finger residue alone, in order to differentiate such residue from explosive residue.

  13. Rapid Quantification of Methamphetamine: Using Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR-FTIR) and Chemometrics

    PubMed Central

    Hughes, Juanita; Ayoko, Godwin; Collett, Simon; Golding, Gary

    2013-01-01

    In Australia and increasingly worldwide, methamphetamine is one of the most commonly seized drugs analysed by forensic chemists. The current well-established GC/MS methods used to identify and quantify methamphetamine are lengthy, expensive processes, but often rapid analysis is requested by undercover police leading to an interest in developing this new analytical technique. Ninety six illicit drug seizures containing methamphetamine (0.1%–78.6%) were analysed using Fourier Transform Infrared Spectroscopy with an Attenuated Total Reflectance attachment and Chemometrics. Two Partial Least Squares models were developed, one using the principal Infrared Spectroscopy peaks of methamphetamine and the other a Hierarchical Partial Least Squares model. Both of these models were refined to choose the variables that were most closely associated with the methamphetamine % vector. Both of the models were excellent, with the principal peaks in the Partial Least Squares model having Root Mean Square Error of Prediction 3.8, R2 0.9779 and lower limit of quantification 7% methamphetamine. The Hierarchical Partial Least Squares model had lower limit of quantification 0.3% methamphetamine, Root Mean Square Error of Prediction 5.2 and R2 0.9637. Such models offer rapid and effective methods for screening illicit drug samples to determine the percentage of methamphetamine they contain. PMID:23936058

  14. Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy: An analytical technique to understand therapeutic responses at the molecular level

    PubMed Central

    Kalmodia, Sushma; Parameswaran, Sowmya; Yang, Wenrong; Barrow, Colin J.; Krishnakumar, Subramanian

    2015-01-01

    Rapid monitoring of the response to treatment in cancer patients is essential to predict the outcome of the therapeutic regimen early in the course of the treatment. The conventional methods are laborious, time-consuming, subjective and lack the ability to study different biomolecules and their interactions, simultaneously. Since; mechanisms of cancer and its response to therapy is dependent on molecular interactions and not on single biomolecules, an assay capable of studying molecular interactions as a whole, is preferred. Fourier Transform Infrared (FTIR) spectroscopy has become a popular technique in the field of cancer therapy with an ability to elucidate molecular interactions. The aim of this study, was to explore the utility of the FTIR technique along with multivariate analysis to understand whether the method has the resolution to identify the differences in the mechanism of therapeutic response. Towards achieving the aim, we utilized the mouse xenograft model of retinoblastoma and nanoparticle mediated targeted therapy. The results indicate that the mechanism underlying the response differed between the treated and untreated group which can be elucidated by unique spectral signatures generated by each group. The study establishes the efficiency of non-invasive, label-free and rapid FTIR method in assessing the interactions of nanoparticles with cellular macromolecules towards monitoring the response to cancer therapeutics. PMID:26568521

  15. Application of multibounce attenuated total reflectance fourier transform infrared spectroscopy and chemometrics for determination of aspartame in soft drinks.

    PubMed

    Khurana, Harpreet Kaur; Cho, Il Kyu; Shim, Jae Yong; Li, Qing X; Jun, Soojin

    2008-02-13

    Aspartame is a low-calorie sweetener commonly used in soft drinks; however, the maximum usage dose is limited by the U.S. Food and Drug Administration. Fourier transform infrared (FTIR) spectroscopy with attenuated total reflectance sampling accessory and partial least-squares regression (PLS) was used for rapid determination of aspartame in soft drinks. On the basis of spectral characterization, the highest R2 value, and lowest PRESS value, the spectral region between 1600 and 1900 cm(-1) was selected for quantitative estimation of aspartame. The potential of FTIR spectroscopy for aspartame quantification was examined and validated by the conventional HPLC method. Using the FTIR method, aspartame contents in four selected carbonated diet soft drinks were found to average from 0.43 to 0.50 mg/mL with prediction errors ranging from 2.4 to 5.7% when compared with HPLC measurements. The developed method also showed a high degree of accuracy because real samples were used for calibration, thus minimizing potential interference errors. The FTIR method developed can be suitably used for routine quality control analysis of aspartame in the beverage-manufacturing sector.

  16. Multivariate analysis of attenuated total reflection-Fourier transform infrared spectroscopic data to confirm the origin of honeys.

    PubMed

    Hennessy, Siobhán; Downey, Gerard; O'Donnell, Colm

    2008-10-01

    Fourier transform infrared (FT-IR) spectroscopy and chemometrics were used to verify the origin of honey samples (n=150) from Europe and South America. Authentic honey samples were collected from five sources, namely unfiltered samples from Mexico in 2004, commercially filtered samples from Ireland and Argentina in 2004, commercially filtered samples from the Czech Republic in 2005 and 2006, and commercially filtered samples from Hungary in 2006. Samples were diluted with distilled water to a standard solids content (70 degrees Brix) and their spectra (2500-12 500 nm) recorded at room temperature using an FT-IR spectrometer equipped with a germanium attenuated total reflection (ATR) accessory. First- and second-derivative and standard normal variate (SNV) data pretreatments were applied to the recorded spectra, which were analyzed using partial least squares (PLS) regression analysis, factorial discriminant analysis (FDA), and soft independent modeling of class analogy (SIMCA). In general, when an attenuated wavelength range (6800-11 500 nm) rather than the whole spectrum (2500-12 500 nm) was studied, higher correct classification rates were achieved. An overall correct classification of 93.3% was obtained for honeys by PLS discriminant analysis, while FDA techniques correctly classified 94.7% of honey samples. Correct classifications of up to 100% were achieved using SIMCA, but models describing some classes had very high false positive rates.

  17. Determination of antioxidant capacity and phenolic content of chocolate by attenuated total reflectance-Fourier transformed-infrared spectroscopy.

    PubMed

    Hu, Yaxi; Pan, Zhi Jie; Liao, Wen; Li, Jiaqi; Gruget, Pierre; Kitts, David D; Lu, Xiaonan

    2016-07-01

    Antioxidant capacity and phenolic content of chocolate, containing different amounts of cacao (35-100%), were determined using attenuated total reflectance (ATR)-Fourier transformed-infrared (FT-IR) spectroscopy (4000-550cm(-1)). Antioxidant capacities were first characterized using DPPH (2,2-diphenyl-1-picrylhydrazyl) and ORAC (oxygen radical absorbance capacity) assays. Phenolic contents, including total phenol and procyanidins monomers, were quantified using the Folin-Ciocalteu assay and high performance liquid chromatography coupled with photodiode array detector (HPLC-DAD), respectively. Five partial least-squares regression (PLSR) models were constructed and cross-validated using FT-IR spectra from 18 types of chocolate and corresponding reference values determined using DPPH, ORAC, Folin-Ciocalteu, and HPLC assays. The models were validated using seven unknown samples of chocolate. PLSR models showed good prediction capability for DPPH [R(2)-P (prediction)=0.88, RMSEP (root mean squares error of prediction)=12.62μmol Trolox/g DFW], ORAC (R(2)-P=0.90, RMSEP=37.92), Folin-Ciocalteu (R(2)-P=0.88, RMSEP=5.08), and (+)-catechin (R(2)-P=0.86, RMSEP=0.10), but lacked accuracy in the prediction of (-)-epicatechin (R(2)-P=0.72, RMSEP=0.57). ATR-FT-IR spectroscopy can be used for rapid prediction of antioxidant capacity, total phenolic content, and (+)-catechin in chocolate. PMID:26920292

  18. Evaluation of low trans fat edible oils by attenuated total reflection-Fourier transform infrared spectroscopy and gas chromatography: a comparison of analytical approaches.

    PubMed

    Tyburczy, Cynthia; Mossoba, Magdi M; Fardin-Kia, Ali Reza; Rader, Jeanne I

    2012-08-01

    Current interest by the food industry in exploring reformulation options that lower the content of trans fat in edible fats and oils requires methods to accurately measure low levels of trans fat. In the present study, the quantitation of trans fat in 25 edible fat and oil samples was evaluated using two current analytical approaches, attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR), and gas chromatography with flame ionization detection (GC-FID) according to Official Methods of the American Oil Chemists' Society. Significant differences between the ATR-FTIR and reference GC-FID quantitations were found for samples with a trans fat content <2% of total fat. These discrepancies could be explained, in part, by the presence of certain oil constituents (e.g., vitamins, carotenoids, high levels of saturated fat) that produced absorbance bands at or near 966 cm(-1) in the ATR-FTIR spectra, a region that was previously identified as being characteristic of isolated trans double bonds. Results demonstrate that the natural content of such oil constituents could result in significant overestimations of trans fat when ATR-FTIR is used to analyze edible fats and oils with a trans fat content <2% of total fat.

  19. Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy on Intact Dried Leaves of Sage (Salvia officinalis L.): Accelerated Chemotaxonomic Discrimination and Analysis of Essential Oil Composition.

    PubMed

    Gudi, Gennadi; Krähmer, Andrea; Krüger, Hans; Schulz, Hartwig

    2015-10-01

    Sage (Salvia officinalis L.) is cultivated worldwide for its aromatic leaves, which are used as herbal spice, and for phytopharmaceutical applications. Fast analytical strategies for essential oil analysis, performed directly on plant material, would reduce the delay between sampling and analytical results. This would enhance product quality by improving technical control of cultivation. The attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) method described here provides a reliable calibration model for quantification of essential oil components [EOCs; R(2) = 0.96; root-mean-square error of cross-validation (RMSECV) = 0.249 mL 100 g(-1) of dry matter (DM); and range = 1.115-5.280 mL 100 g(-1) of DM] and main constituents [e.g., α-thujone/β-thujone; R(2) = 0.97/0.86; RMSECV = 0.0581/0.0856 mL 100 g(-1) of DM; and range = 0.010-1.252/0.005-0.893 mL 100 g(-1) of DM] directly on dried intact leaves of sage. Except for drying, no further sample preparation is required for ATR-FTIR, and the measurement time of less than 5 min per sample contrasts with the most common alternative of hydrodistillation followed by gas chromatography analysis, which can take several hours per sample. PMID:26360136

  20. Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy on Intact Dried Leaves of Sage (Salvia officinalis L.): Accelerated Chemotaxonomic Discrimination and Analysis of Essential Oil Composition.

    PubMed

    Gudi, Gennadi; Krähmer, Andrea; Krüger, Hans; Schulz, Hartwig

    2015-10-01

    Sage (Salvia officinalis L.) is cultivated worldwide for its aromatic leaves, which are used as herbal spice, and for phytopharmaceutical applications. Fast analytical strategies for essential oil analysis, performed directly on plant material, would reduce the delay between sampling and analytical results. This would enhance product quality by improving technical control of cultivation. The attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) method described here provides a reliable calibration model for quantification of essential oil components [EOCs; R(2) = 0.96; root-mean-square error of cross-validation (RMSECV) = 0.249 mL 100 g(-1) of dry matter (DM); and range = 1.115-5.280 mL 100 g(-1) of DM] and main constituents [e.g., α-thujone/β-thujone; R(2) = 0.97/0.86; RMSECV = 0.0581/0.0856 mL 100 g(-1) of DM; and range = 0.010-1.252/0.005-0.893 mL 100 g(-1) of DM] directly on dried intact leaves of sage. Except for drying, no further sample preparation is required for ATR-FTIR, and the measurement time of less than 5 min per sample contrasts with the most common alternative of hydrodistillation followed by gas chromatography analysis, which can take several hours per sample.

  1. Structure and orientation of two voltage-dependent anion-selective channel isoforms. An attenuated total reflection fourier-transform infrared spectroscopy study.

    PubMed

    Abrecht, H; Goormaghtigh, E; Ruysschaert, J M; Homble, F

    2000-12-29

    Two VDAC (voltage-dependent anion-selective channel) isoforms were purified from seed cotyledons of Phaseolus vulgaris by chromatofocusing chromatography. Attenuated total reflection Fourier-transform infrared (ATR-FTIR) spectroscopy was used to study the structural properties of the two isoforms reconstituted in a mixture of asolectin and 5% stigmasterol. The IR spectra of the two VDAC isoforms were highly similar indicating 50 to 53% anti-parallel beta-sheet. The orientation of the beta-strands relative to the barrel axis was calculated from the experimentally obtained dichroic ratios of the amide I beta-sheet component and the amide II band. Comparing the IR spectra of the reconstituted VDAC isoforms with the IR spectra of the bacterial porin OmpF, for which a high resolution structure is available, provided evidence for a general structural organization of the VDAC isoforms similar to that of bacterial porins. Hydrogen-deuterium exchange measurements indicated that the exchange of the amide protons occurs to a higher extent in the two VDAC isoforms than in the OmpF porin.

  2. Optimized data analysis algorithm for on-site chemical identification using a hand-held attenuated total reflection Fourier transform infrared (ATR FT-IR) spectrometer.

    PubMed

    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.

  3. Optimized data analysis algorithm for on-site chemical identification using a hand-held attenuated total reflection Fourier transform infrared (ATR FT-IR) spectrometer.

    PubMed

    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. PMID:24359653

  4. A simple, sensitive and non-destructive technique for characterizing bovine dental enamel erosion: attenuated total reflection Fourier transform infrared spectroscopy

    PubMed Central

    Kim, In-Hye; Son, Jun Sik; Min, Bong Ki; Kim, Young Kyoung; Kim, Kyo-Han; Kwon, Tae-Yub

    2016-01-01

    Although many techniques are available to assess enamel erosion in vitro, a simple, non-destructive method with sufficient sensitivity for quantifying dental erosion is required. This study characterized the bovine dental enamel erosion induced by various acidic beverages in vitro using attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy. Deionized water (control) and 10 acidic beverages were selected to study erosion, and the pH and neutralizable acidity were measured. Bovine anterior teeth (110) were polished with up to 1 200-grit silicon carbide paper to produce flat enamel surfaces, which were then immersed in 20 mL of the beverages for 30 min at 37 °C. The degree of erosion was evaluated using ATR-FTIR spectroscopy and Vickers' microhardness measurements. The spectra obtained were interpreted in two ways that focused on the ν1, ν3 phosphate contour: the ratio of the height amplitude of ν3 PO4 to that of ν1 PO4 (Method 1) and the shift of the ν3 PO4 peak to a higher wavenumber (Method 2). The percentage changes in microhardness after the erosion treatments were primarily affected by the pH of the immersion media. Regression analyses revealed highly significant correlations between the surface hardness change and the degree of erosion, as detected by ATR-FTIR spectroscopy (P<0.001). Method 1 was the most sensitive to these changes, followed by surface hardness change measurements and Method 2. This study suggests that ATR-FTIR spectroscopy is potentially advantageous over the microhardness test as a simple, non-destructive, sensitive technique for the quantification of enamel erosion. PMID:27025266

  5. A simple, sensitive and non-destructive technique for characterizing bovine dental enamel erosion: attenuated total reflection Fourier transform infrared spectroscopy.

    PubMed

    Kim, In-Hye; Son, Jun Sik; Min, Bong Ki; Kim, Young Kyoung; Kim, Kyo-Han; Kwon, Tae-Yub

    2016-03-30

    Although many techniques are available to assess enamel erosion in vitro, a simple, non-destructive method with sufficient sensitivity for quantifying dental erosion is required. This study characterized the bovine dental enamel erosion induced by various acidic beverages in vitro using attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy. Deionized water (control) and 10 acidic beverages were selected to study erosion, and the pH and neutralizable acidity were measured. Bovine anterior teeth (110) were polished with up to 1 200-grit silicon carbide paper to produce flat enamel surfaces, which were then immersed in 20 mL of the beverages for 30 min at 37 °C. The degree of erosion was evaluated using ATR-FTIR spectroscopy and Vickers' microhardness measurements. The spectra obtained were interpreted in two ways that focused on the ν1, ν3 phosphate contour: the ratio of the height amplitude of ν3 PO4 to that of ν1 PO4 (Method 1) and the shift of the ν3 PO4 peak to a higher wavenumber (Method 2). The percentage changes in microhardness after the erosion treatments were primarily affected by the pH of the immersion media. Regression analyses revealed highly significant correlations between the surface hardness change and the degree of erosion, as detected by ATR-FTIR spectroscopy (P<0.001). Method 1 was the most sensitive to these changes, followed by surface hardness change measurements and Method 2. This study suggests that ATR-FTIR spectroscopy is potentially advantageous over the microhardness test as a simple, non-destructive, sensitive technique for the quantification of enamel erosion.

  6. Determination of thermally induced trans-fatty acids in soybean oil by attenuated total reflectance fourier transform infrared spectroscopy and gas chromatography analysis.

    PubMed

    Li, An; Ha, Yiming; Wang, Feng; Li, Weiming; Li, Qingpeng

    2012-10-24

    The intake of edible oil containing trans-fatty acids has deleterious effects mainly on the cardiovascular system. Thermal processes such as refining and frying cause the formation of trans-fatty acids in edible oil. This study was conducted to investigate the possible formation of trans-fatty acids because of the heat treatment of soybean oil. The types of trans-fatty acids in heated soybean oil are determined by attenuated total reflectance Fourier transform infrared spectroscopy and gas chromatography-mass spectrometry methods. The effects of the heating temperature on the trans-fatty acids in soybean oil were evaluated using gas chromatography flame ionization detection analysis. Results show that heat treatment at 240 °C causes the formation of trans-fatty acids in soybean oil and the amount of trans-fatty acids increases with heating time. The only peak observed at 966 cm(-1) of the samples indicates the formation of nonconjugated trans isomers in the heated soybean oil. The major types of trans-fatty acids formed were trans-polyunsaturated fatty acids. Significant increases (P < 0.05) in the amounts of two trans-linoleic acids (C18:2-9c,12t and C18:2-9t,12c) and four trans-linolenic acids (C18:3-9c,12c,15t, C18:3-9t,12c,15c, and C18:3-9t,12t,15c/C18:3-9t,12c,15t) in soybean oil heated to temperatures exceeding 200 °C were compared with those of the control sample. The heating temperature and duration should be considered to reduce the formation of trans-fatty acids during thermal treatment.

  7. Chemical Functionalization of Germanium with Dextran Brushes for Immobilization of Proteins Revealed by Attenuated Total Reflection Fourier Transform Infrared Difference Spectroscopy.

    PubMed

    Schartner, Jonas; Hoeck, Nina; Güldenhaupt, Jörn; Mavarani, Laven; Nabers, Andreas; Gerwert, Klaus; Kötting, Carsten

    2015-07-21

    Protein immobilization studied by attenuated total reflection Fourier transform infrared (ATR-FT-IR) difference spectroscopy is an emerging field enabling the study of proteins at atomic detail. Gold or glass surfaces are frequently used for protein immobilization. Here, we present an alternative method for protein immobilization on germanium. Because of its high refractive index and broad spectral window germanium is the best material for ATR-FT-IR spectroscopy of thin layers. So far, this technique was mainly used for protein monolayers, which lead to a limited signal-to-noise ratio. Further, undesired protein-protein interactions can occur in a dense layer. Here, the germanium surface was functionalized with thiols and stepwise a dextran brush was generated. Each step was monitored by ATR-FT-IR spectroscopy. We compared a 70 kDa dextran with a 500 kDa dextran regarding the binding properties. All surfaces were characterized by atomic force microscopy, revealing thicknesses between 40 and 110 nm. To analyze the capability of our system we utilized N-Ras on mono-NTA (nitrilotriacetic acid) functionalized dextran, and the amount of immobilized Ras corresponded to several monolayers. The protein stability and loading capacity was further improved by means of tris-NTA for immobilization. Small-molecule-induced changes were revealed with an over 3 times higher signal-to-noise ratio compared to monolayers. This improvement may allow the observation of very small and so far hidden changes in proteins upon stimulus. Furthermore, we immobilized green fluorescent protein (GFP) and mCherry simultaneously enabling an analysis of the surface by fluorescence microscopy. The absence of a Förster resonance energy transfer (FRET) signal demonstrated a large protein-protein distance, indicating an even distribution of the protein within the dextran.

  8. A simple, sensitive and non-destructive technique for characterizing bovine dental enamel erosion: attenuated total reflection Fourier transform infrared spectroscopy.

    PubMed

    Kim, In-Hye; Son, Jun Sik; Min, Bong Ki; Kim, Young Kyoung; Kim, Kyo-Han; Kwon, Tae-Yub

    2016-03-01

    Although many techniques are available to assess enamel erosion in vitro, a simple, non-destructive method with sufficient sensitivity for quantifying dental erosion is required. This study characterized the bovine dental enamel erosion induced by various acidic beverages in vitro using attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy. Deionized water (control) and 10 acidic beverages were selected to study erosion, and the pH and neutralizable acidity were measured. Bovine anterior teeth (110) were polished with up to 1 200-grit silicon carbide paper to produce flat enamel surfaces, which were then immersed in 20 mL of the beverages for 30 min at 37 °C. The degree of erosion was evaluated using ATR-FTIR spectroscopy and Vickers' microhardness measurements. The spectra obtained were interpreted in two ways that focused on the ν1, ν3 phosphate contour: the ratio of the height amplitude of ν3 PO4 to that of ν1 PO4 (Method 1) and the shift of the ν3 PO4 peak to a higher wavenumber (Method 2). The percentage changes in microhardness after the erosion treatments were primarily affected by the pH of the immersion media. Regression analyses revealed highly significant correlations between the surface hardness change and the degree of erosion, as detected by ATR-FTIR spectroscopy (P<0.001). Method 1 was the most sensitive to these changes, followed by surface hardness change measurements and Method 2. This study suggests that ATR-FTIR spectroscopy is potentially advantageous over the microhardness test as a simple, non-destructive, sensitive technique for the quantification of enamel erosion. PMID:27025266

  9. Nondestructive and rapid determination of nitrate in soil, dry deposits and aerosol samples using KBr-matrix with diffuse reflectance Fourier transform infrared spectroscopy (DRIFTS).

    PubMed

    Verma, Santosh Kumar; Deb, Manas Kanti

    2007-01-23

    This paper presents the development of a new, rapid and precise analytical method for submicrogram levels of nitrate (NO3-) in environmental samples like soil, dry deposit samples, and coarse and fine aerosol particles. The determination of submicrogram levels of nitrate is based on the selection of a quantitative analytical peak at 1385 cm(-1) among the three observed vibrational peaks and preparing calibration curves using different known concentrations of nitrate by diffuse reflectance Fourier transform infra red spectrometric (DRIFTS) technique. Pre-weighed and ground infrared (IR) grade KBr was used as substrate over which remarkably wide range of known concentration of nitrate was sprayed and dried. The dried sample was analyzed by DRIFTS and absorbance was measured. Eight calibration curves for four different concentration ranges of nitrate for absorbance as well as peak area were prepared for samples containing lower and relatively higher values of nitrate. The relative standard deviation (n=8) for the nitrate concentration ranges, 0.05-40, 0.05-1.5, 1.5-25, 5-40 microg/0.1 g KBr were in the range 1.6-2.3% for the above calibration curves. The limit of detection (LOD) of the method is 0.07 microg g(-1) NO3-. The F- and t-tests were performed to check the analytical quality assurance test. The noteworthy feature of the reported method is the noninterference of any of the associated cations. The results were compared with that of ion-chromatographic method with high degree of acceptability. The method can be applied in wide concentration ranges. The method is reagent less, nondestructive, very fast, repeatable, and accurate and has high sample throughput value.

  10. Quantitative determination of polyphosphate in sediments using Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR) spectroscopy and partial least squares regression.

    PubMed

    Khoshmanesh, Aazam; Cook, Perran L M; Wood, Bayden R

    2012-08-21

    Phosphorus (P) is a major cause of eutrophication and subsequent loss of water quality in freshwater ecosystems. A major part of the flux of P to eutrophic lake sediments is organically bound or of biogenic origin. Despite the broad relevance of polyphosphate (Poly-P) in bioremediation and P release processes in the environment, its quantification is not yet well developed for sediment samples. Current methods possess significant disadvantages because of the difficulties associated with using a single extractant to extract a specific P compound without altering others. A fast and reliable method to estimate the quantitative contribution of microorganisms to sediment P release processes is needed, especially when an excessive P accumulation in the form of polyphosphate (Poly-P) occurs. Development of novel approaches for application of emerging spectroscopic techniques to complex environmental matrices such as sediments significantly contributes to the speciation models of P mobilization, biogeochemical nutrient cycling and development of nutrient models. In this study, for the first time Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR) spectroscopy in combination with partial least squares (PLS) was used to quantify Poly-P in sediments. To reduce the high absorption matrix components in sediments such as silica, a physical extraction method was developed to separate sediment biological materials from abiotic particles. The aim was to achieve optimal separation of the biological materials from sediment abiotic particles with minimum chemical change in the sample matrix prior to ATR-FTIR analysis. Using a calibration set of 60 samples for the PLS prediction models in the Poly-P concentration range of 0-1 mg g(-1) d.w. (dry weight of sediment) (R(2) = 0.984 and root mean square error of prediction RMSEP = 0.041 at Factor-1) Poly-P could be detected at less than 50 μg g(-l) d.w. Using this technique, there is no solvent extraction or chemical

  11. Quantitative determination of polyphosphate in sediments using Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR) spectroscopy and partial least squares regression.

    PubMed

    Khoshmanesh, Aazam; Cook, Perran L M; Wood, Bayden R

    2012-08-21

    Phosphorus (P) is a major cause of eutrophication and subsequent loss of water quality in freshwater ecosystems. A major part of the flux of P to eutrophic lake sediments is organically bound or of biogenic origin. Despite the broad relevance of polyphosphate (Poly-P) in bioremediation and P release processes in the environment, its quantification is not yet well developed for sediment samples. Current methods possess significant disadvantages because of the difficulties associated with using a single extractant to extract a specific P compound without altering others. A fast and reliable method to estimate the quantitative contribution of microorganisms to sediment P release processes is needed, especially when an excessive P accumulation in the form of polyphosphate (Poly-P) occurs. Development of novel approaches for application of emerging spectroscopic techniques to complex environmental matrices such as sediments significantly contributes to the speciation models of P mobilization, biogeochemical nutrient cycling and development of nutrient models. In this study, for the first time Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR) spectroscopy in combination with partial least squares (PLS) was used to quantify Poly-P in sediments. To reduce the high absorption matrix components in sediments such as silica, a physical extraction method was developed to separate sediment biological materials from abiotic particles. The aim was to achieve optimal separation of the biological materials from sediment abiotic particles with minimum chemical change in the sample matrix prior to ATR-FTIR analysis. Using a calibration set of 60 samples for the PLS prediction models in the Poly-P concentration range of 0-1 mg g(-1) d.w. (dry weight of sediment) (R(2) = 0.984 and root mean square error of prediction RMSEP = 0.041 at Factor-1) Poly-P could be detected at less than 50 μg g(-l) d.w. Using this technique, there is no solvent extraction or chemical

  12. Application of micro-attenuated total reflectance Fourier transform infrared spectroscopy to ink examination in signatures written with ballpoint pen on questioned documents.

    PubMed

    Nam, Yun Sik; Park, Jin Sook; Lee, Yeonhee; Lee, Kang-Bong

    2014-05-01

    Questioned documents examined in a forensic laboratory sometimes contain signatures written with ballpoint pen inks; these signatures were examined to assess the feasibility of micro-attenuated total reflectance (ATR) Fourier transform infrared (FTIR) spectroscopy as a forensic tool. Micro-ATR FTIR spectra for signatures written with 63 ballpoint pens available commercially in Korea were obtained and used to construct an FTIR spectral database. A library-searching program was utilized to identify the manufacturer, blend, and model of each black ballpoint pen ink based upon their FTIR peak intensities, positions, and patterns in the spectral database. This FTIR technique was also successfully used in determining the sequence of homogeneous line intersections from the crossing lines of two ballpoint pen signatures. We have demonstrated with a set of sample documents that micro-ATR FTIR is a viable nondestructive analytical method that can be used to identify the origin of the ballpoint pen ink used to mark signatures. PMID:24661236

  13. In situ nondestructive identification of natural dyes in ancient textiles by reflection fourier transform mid-infrared (FT-MIR) spectroscopy.

    PubMed

    De Luca, Eleonora; Bruni, Silvia; Sali, Diego; Guglielmi, Vittoria; Belloni, Paolo

    2015-01-01

    Silk embroideries and cotton grounds of ancient Caucasian (Kaitag) textiles were analyzed in situ by a portable Fourier transform infrared (FT-IR) spectrometer equipped with a reflection module. Differently colored areas were analyzed for the purpose of identifying the dyes fixed on the fibers. The spectra so obtained were elaborated by calculating the corresponding second derivative, and a library search was then performed using a database including the second derivative spectra of a large range of historical dyes and the corresponding undyed fibers. The results presented here suggest that this technique, combined with the library search method, has a good capability of recognizing natural dyes on both types of ancient textile fibers, in an entirely non-destructive way.

  14. In situ nondestructive identification of natural dyes in ancient textiles by reflection fourier transform mid-infrared (FT-MIR) spectroscopy.

    PubMed

    De Luca, Eleonora; Bruni, Silvia; Sali, Diego; Guglielmi, Vittoria; Belloni, Paolo

    2015-01-01

    Silk embroideries and cotton grounds of ancient Caucasian (Kaitag) textiles were analyzed in situ by a portable Fourier transform infrared (FT-IR) spectrometer equipped with a reflection module. Differently colored areas were analyzed for the purpose of identifying the dyes fixed on the fibers. The spectra so obtained were elaborated by calculating the corresponding second derivative, and a library search was then performed using a database including the second derivative spectra of a large range of historical dyes and the corresponding undyed fibers. The results presented here suggest that this technique, combined with the library search method, has a good capability of recognizing natural dyes on both types of ancient textile fibers, in an entirely non-destructive way. PMID:25587824

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

    PubMed

    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. PMID:24067568

  16. Direct and simultaneous quantification of tannin mean degree of polymerization and percentage of galloylation in grape seeds using diffuse reflectance fourier transform-infrared spectroscopy.

    PubMed

    Pappas, Christos; Kyraleou, Maria; Voskidi, Eleni; Kotseridis, Yorgos; Taranilis, Petros A; Kallithraka, Stamatina

    2015-02-01

    The direct and simultaneous quantitative determination of the mean degree of polymerization (mDP) and the degree of galloylation (%G) in grape seeds were quantified using diffuse reflectance infrared Fourier transform spectroscopy and partial least squares (PLS). The results were compared with those obtained using the conventional analysis employing phloroglucinolysis as pretreatment followed by high performance liquid chromatography-UV and mass spectrometry detection. Infrared spectra were recorded in solid state samples after freeze drying. The 2nd derivative of the 1832 to 1416 and 918 to 739 cm(-1) spectral regions for the quantification of mDP, the 2nd derivative of the 1813 to 607 cm(-1) spectral region for the degree of %G determination and PLS regression were used. The determination coefficients (R(2) ) of mDP and %G were 0.99 and 0.98, respectively. The corresponding values of the root-mean-square error of calibration were found 0.506 and 0.692, the root-mean-square error of cross validation 0.811 and 0.921, and the root-mean-square error of prediction 0.612 and 0.801. The proposed method in comparison with the conventional method is simpler, less time consuming, more economical, and requires reduced quantities of chemical reagents and fewer sample pretreatment steps. It could be a starting point for the design of more specific models according to the requirements of the wineries. PMID:25588697

  17. Direct and simultaneous quantification of tannin mean degree of polymerization and percentage of galloylation in grape seeds using diffuse reflectance fourier transform-infrared spectroscopy.

    PubMed

    Pappas, Christos; Kyraleou, Maria; Voskidi, Eleni; Kotseridis, Yorgos; Taranilis, Petros A; Kallithraka, Stamatina

    2015-02-01

    The direct and simultaneous quantitative determination of the mean degree of polymerization (mDP) and the degree of galloylation (%G) in grape seeds were quantified using diffuse reflectance infrared Fourier transform spectroscopy and partial least squares (PLS). The results were compared with those obtained using the conventional analysis employing phloroglucinolysis as pretreatment followed by high performance liquid chromatography-UV and mass spectrometry detection. Infrared spectra were recorded in solid state samples after freeze drying. The 2nd derivative of the 1832 to 1416 and 918 to 739 cm(-1) spectral regions for the quantification of mDP, the 2nd derivative of the 1813 to 607 cm(-1) spectral region for the degree of %G determination and PLS regression were used. The determination coefficients (R(2) ) of mDP and %G were 0.99 and 0.98, respectively. The corresponding values of the root-mean-square error of calibration were found 0.506 and 0.692, the root-mean-square error of cross validation 0.811 and 0.921, and the root-mean-square error of prediction 0.612 and 0.801. The proposed method in comparison with the conventional method is simpler, less time consuming, more economical, and requires reduced quantities of chemical reagents and fewer sample pretreatment steps. It could be a starting point for the design of more specific models according to the requirements of the wineries.

  18. Application of multivariate chemometric techniques for simultaneous determination of five parameters of cottonseed oil by single bounce attenuated total reflectance Fourier transform infrared spectroscopy.

    PubMed

    Talpur, M Younis; Kara, Huseyin; Sherazi, S T H; Ayyildiz, H Filiz; Topkafa, Mustafa; Arslan, Fatma Nur; Naz, Saba; Durmaz, Fatih; Sirajuddin

    2014-11-01

    Single bounce attenuated total reflectance (SB-ATR) Fourier transform infrared (FTIR) spectroscopy in conjunction with chemometrics was used for accurate determination of free fatty acid (FFA), peroxide value (PV), iodine value (IV), conjugated diene (CD) and conjugated triene (CT) of cottonseed oil (CSO) during potato chips frying. Partial least square (PLS), stepwise multiple linear regression (SMLR), principal component regression (PCR) and simple Beer׳s law (SBL) were applied to develop the calibrations for simultaneous evaluation of five stated parameters of cottonseed oil (CSO) during frying of French frozen potato chips at 170°C. Good regression coefficients (R(2)) were achieved for FFA, PV, IV, CD and CT with value of >0.992 by PLS, SMLR, PCR, and SBL. Root mean square error of prediction (RMSEP) was found to be less than 1.95% for all determinations. Result of the study indicated that SB-ATR FTIR in combination with multivariate chemometrics could be used for accurate and simultaneous determination of different parameters during the frying process without using any toxic organic solvent. PMID:25127621

  19. Detection and quantification of soymilk in cow-buffalo milk using Attenuated Total Reflectance Fourier Transform Infrared spectroscopy (ATR-FTIR).

    PubMed

    Jaiswal, Pranita; Jha, Shyam Narayan; Borah, Anjan; Gautam, Anuj; Grewal, Manpreet Kaur; Jindal, Gaurav

    2015-02-01

    Milk consumption is steadily increasing, especially in India and China, due to rising income. To bridge the gap between supply and demand, unscrupulous milk vendors add milk-like products from vegetable sources (soymilk) to milk without declaration. A rapid detection technique is required to enforce the safety norms of food regulatory authorities. Fourier Transform Infrared (FTIR) spectroscopy has demonstrated potential as a rapid quality monitoring method and was therefore explored for detection of soymilk in milk. In the present work, spectra of milk, soymilk (SM), and milk adulterated with known quantity of SM were acquired in the wave number range of 4000-500cm(-1) using Attenuated Total Reflectance (ATR)-FTIR. The acquired spectra revealed differences amongst milk, SM and adulterated milk (AM) samples in the wave number range of 1680-1058cm(-1). This region encompasses the absorption frequency of amide-I, amide-II, amide-III, beta-sheet protein, α-tocopherol and Soybean Kunitz Trypsin Inhibitor. Principal component analysis (PCA) showed clustering of samples based on SM concentration at 5% level of significance and thus SM could be detected in milk using ATR-FTIR. The SM was best predicted in the range of 1472-1241cm(-1) using multiple linear regression with coefficient of determination (R(2)) of 0.99 and 0.92 for calibration and validation, respectively.

  20. Sampling and quantitative analysis of clean B. subtilis spores at sub-monolayer coverage by reflectance fourier transform infrared microscopy using gold-coated filter substrates.

    PubMed

    Brooke, Heather; Perkins, David L; Setlow, Barbara; Setlow, Peter; Bronk, Burt V; Myrick, Michael L

    2008-08-01

    A study was conducted to determine the concentration dependency of the mid-infrared (MIR) absorbance of bacterial spores. A range of concentrations of Bacillus subtilis endospores filtered across gold-coated filter membranes were analyzed by Fourier transform infrared (FT-IR) reflectance microscopy. Calibration curves were derived from the peak absorbances associated with Amide A, Amide I, and Amide II vibrational frequencies by automatic baseline fitting to remove most of the scattering contribution. Linear relationships (R2 >or= 0.99) were observed between the concentrations of spores and the baseline-corrected peak absorbance for each frequency studied. Detection limits for our sampled area of 100 x100 microm2 were determined to be 79, 39, and 184 spores (or 7.92 x 10(5), 3.92 x 10(5), and 1.84 x 10(6) spores/cm2) for the Amide A, Amide I, and Amide II peaks, respectively. Absorbance increased linearly above the scattering baseline with particle surface concentration up to 0.9 monolayer (ML) coverage, with the monolayer density calculated to be approximately 1.17 x 10(8) spores/cm2. Scattering as a function of surface concentration, as estimated from extinction values at wavelengths exhibiting low absorbance, becomes nonlinear at a much lower surface concentration. The apparent scattering cross-section per spore decreased monotonically as concentrations increased toward 1.2 ML, while the absolute scattering decreased between 0.9 ML and 1.2 ML coverage. Calculations suggest that transverse spatial coherence effects are the origin of this nonlinearity, while the onset of nonlinearity in the baseline-corrected absorption is probably due to multiple scattering effects, which appear at a high surface concentration. Absorption cross-sections at peaks of the three bands were measured to be (2.15 +/- 0.05) x 10(-9), (1.48 +/- 0.03) x 10(-9), and (0.805 +/- 0.023) x 10(-9) cm2, respectively. These values are smaller by a factor of 2-4 than expected from the literature

  1. Surface effects in photochemistry: an in situ cylindrical internal reflection-Fourier transform infrared investigation of the effect of ring substituents on chemisorption onto TiO[sub 2] ceramic membranes

    SciTech Connect

    Tunesi, S.; Anderson, M.A. )

    1992-02-01

    The role of phenyl substituent groups in the formation of surface complexes at the surface of titanium dioxide semiconducting ceramic membranes is investigated with cylindrical internal reflection-Fourier transform infrared (CIR-FTIR) spectroscopy. The CIR-FTIR study presented in this article allows for direct comparison between adsorption mechanisms derived from vibrational spectra at the semiconductor-liquid interface and surface structures influencing aqueous heterogeneous photochemical reactions. Therefore, chemisorption mechanisms we derived for benzoic acid and its substituted compounds could be used for the prediction of their photodegradation behavior. This IR investigation confirms that no adsorption is detectable on the rutile phase of TiO[sub 2], thus excluding the role of 5-fold coordinated Ti cations in the adsorption mechanisms. We observed that, for anatase surface, isolated carboxyl groups do not generate a favorable adsorption equilibrium (e.g., benzoic acid). It is proposed that amino and hydroxyl groups substituted in ortho position to a carboxyl group (e.g., salicylic, 3-chlorosalicylic, and anthranilic acids) may lead to a mononuclear bidentate coordination complex with 4-fold coordinated surface titanium cations. The higher adsorption level observed for phthalic acid is interpreted as due to its possibility of adsorbing on a greater number of anatase surface sites, by forming two different surface complexes, involving one or both carboxyl groups. A relationship between change in vibrational spectra of the carboxyl group, for substituted benzoic derivatives, and acidic dissociation constants is presented. 37 refs., 7 figs., 1 tab.

  2. Direct determination of sorbitol and sodium glutamate by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) in the thermostabilizer employed in the production of yellow-fever vaccine.

    PubMed

    de Castro, Eduardo da S G; Cassella, Ricardo J

    2016-05-15

    Reference methods for quality control of vaccines usually require treatment of the samples before analysis. These procedures are expensive, time-consuming, unhealthy and require careful manipulation of the sample, making them a potential source of analytical errors. This work proposes a novel method for the quality control of thermostabilizer samples of the yellow fever vaccine employing attenuated total reflectance Fourier transform infrared spectrometry (ATR-FTIR). The main advantage of the proposed method is the possibility of direct determination of the analytes (sodium glutamate and sorbitol) without any pretreatment of the samples. Operational parameters of the FTIR technique, such as the number of accumulated scans and nominal resolution, were evaluated. The best conditions for sodium glutamate were achieved when 64 scans were accumulated using a nominal resolution of 4 cm(-1). The measurements for sodium glutamate were performed at 1347 cm(-1) (baseline correction between 1322 and 1369 cm(-1)). In the case of sorbitol, the measurements were done at 890cm(-1) (baseline correction between 825 and 910 cm(-1)) using a nominal resolution of 2 cm(-1) with 32 accumulated scans. In both cases, the quantitative variable was the band height. Recovery tests were performed in order to evaluate the accuracy of the method and recovery percentages in the range 93-106% were obtained. Also, the methods were compared with reference methods and no statistical differences were observed. The limits of detection and quantification for sodium glutamate were 0.20 and 0.62% (m/v), respectively, whereas for sorbitol they were 1 and 3.3% (m/v), respectively. PMID:26992492

  3. Direct determination of sorbitol and sodium glutamate by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) in the thermostabilizer employed in the production of yellow-fever vaccine.

    PubMed

    de Castro, Eduardo da S G; Cassella, Ricardo J

    2016-05-15

    Reference methods for quality control of vaccines usually require treatment of the samples before analysis. These procedures are expensive, time-consuming, unhealthy and require careful manipulation of the sample, making them a potential source of analytical errors. This work proposes a novel method for the quality control of thermostabilizer samples of the yellow fever vaccine employing attenuated total reflectance Fourier transform infrared spectrometry (ATR-FTIR). The main advantage of the proposed method is the possibility of direct determination of the analytes (sodium glutamate and sorbitol) without any pretreatment of the samples. Operational parameters of the FTIR technique, such as the number of accumulated scans and nominal resolution, were evaluated. The best conditions for sodium glutamate were achieved when 64 scans were accumulated using a nominal resolution of 4 cm(-1). The measurements for sodium glutamate were performed at 1347 cm(-1) (baseline correction between 1322 and 1369 cm(-1)). In the case of sorbitol, the measurements were done at 890cm(-1) (baseline correction between 825 and 910 cm(-1)) using a nominal resolution of 2 cm(-1) with 32 accumulated scans. In both cases, the quantitative variable was the band height. Recovery tests were performed in order to evaluate the accuracy of the method and recovery percentages in the range 93-106% were obtained. Also, the methods were compared with reference methods and no statistical differences were observed. The limits of detection and quantification for sodium glutamate were 0.20 and 0.62% (m/v), respectively, whereas for sorbitol they were 1 and 3.3% (m/v), respectively.

  4. Quantitative determination of two polymorphic forms of imatinib mesylate in a drug substance and tablet formulation by X-ray powder diffraction, differential scanning calorimetry and attenuated total reflectance Fourier transform infrared spectroscopy.

    PubMed

    Bellur Atici, Esen; Karlığa, Bekir

    2015-10-10

    Imatinib has been identified as a tyrosine kinase inhibitor that selectively inhibits the Abl tyrosine kinases, including Bcr-Abl. The active substance used in drug product is the mesylate salt form of imatinib, a phenylaminopyrimidine derivative and chemically named as N-(3-(4-(pyridin-3-yl) pyrimidin-2-ylamino)-4-methylphenyl)-4-((4-methylpiperazin-1-yl) methyl)-benzamide methanesulfonic acid salt. It exhibits many polymorphic forms and most stable and commercialized polymorphs are known as α and β forms. Molecules in α and β polymorphic forms exhibit significant conformational differences due to their different intra- and intermolecular interactions, which stabilize their molecular conformations and affect their physicochemical properties such as bulk density, melting point, solubility, stability, and processability. The manufacturing process of a drug tablet included granulation, compression, coating, and drying may cause polymorphic conversions. Therefore, polymorphic content of the drug substance should be controlled during quality control and stability testing. Attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy, differential scanning calorimetry (DSC), and powder X-ray diffraction (PXRD) methods were evaluated for determination of the polymorphic content of the drug substance and drug product; and PXRD was the most accurate technique and selected as preferred method and validated. Prior to development of a quantification method, pure α and β polymorphs were characterized and used throughout the method development and validation studies. Mixtures with different ratios of α and β forms were scanned using X-ray diffractometer with a scan rate of 0.250°/min over an angular range of 19.5-21.0° 2θ and the peak heights for characteristic peak of β form at 20.5 ± 0.2° 2θ diffraction angle were used to generate a calibration curve. The detection limit of β polymorph in α form imatinib mesylate tablets was found as 4% and

  5. Characterization of silver halide fiber optics and hollow silica waveguides for use in the construction of a mid-infrared attenuated total reflection fourier transform infrared (ATR FT-IR) spectroscopy probe.

    PubMed

    Damin, Craig A; Sommer, André J

    2013-11-01

    Advances in fiber optic materials have allowed for the construction of fibers and waveguides capable of transmitting infrared radiation. An investigation of the transmission characteristics associated with two commonly used types of infrared-transmitting fibers/waveguides for prospective use in a fiber/waveguide-coupled attenuated total internal reflection (ATR) probe was performed. Characterization of silver halide polycrystalline fiber optics and hollow silica waveguides was done on the basis of the transmission of infrared light using a conventional fiber optic coupling accessory and an infrared microscope. Using the fiber optic coupling accessory, the average percent transmission for three silver halide fibers was 18.1 ± 6.1% relative to a benchtop reflection accessory. The average transmission for two hollow waveguides (HWGs) using the coupling accessory was 8.0 ± 0.3%. (Uncertainties in the relative percent transmission represent the standard deviations.) Reduced transmission observed for the HWGs was attributed to the high numerical aperture of the coupling accessory. Characterization of the fibers/waveguides using a zinc selenide lens objective on an infrared microscope indicated 24.1 ± 7.2% of the initial light input into the silver halide fibers was transmitted. Percent transmission obtained for the HWGs was 98.7 ± 0.1%. Increased transmission using the HWGs resulted from the absence or minimization of insertion and scattering losses due to the hollow air core and a better-matched numerical aperture. The effect of bending on the transmission characteristics of the fibers/waveguides was also investigated. Significant deviations in the transmission of infrared light by the solid-core silver halide fibers were observed for various bending angles. Percent transmission greater than 98% was consistently observed for the HWGs at the bending angles. The combined benefits of high percent transmission, reproducible instrument responses, and increased bending

  6. 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.

    PubMed

    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.

  7. Nondestructive Determination of the Age of 20th-Century Oil-Binder Ink Prints Using Attenuated Total Reflection Fourier Transform Infrared Spectroscopy (ATR FT-IR): A Case Study with Postage Stamps from the Łódź Ghetto.

    PubMed

    Bower, Nathan W; Blanchet, Conor J K; Epstein, Michael S

    2016-01-01

    The ability to determine the production date for a painting or print would be of great benefit in the forensic detection of fakes and forgeries as well as in art history and conservation. Changes in the pigments used at different times have been invaluable in detecting incongruities that suggest fraud, but relatively little work has been published that uses the chemical changes in oil binders as they dry to determine when an ink print or an oil painting was made. Using attenuated total reflectance-Fourier transform infrared (ATR FT-IR) spectroscopy and samples with known dates, we calibrate the drying of oil binders in inks and paints and cross-validate the paints with pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS). We apply the ink calibration to a case study involving the age determination of possible philatelic counterfeits from a World War II Jewish Ghetto in Occupied Poland, obtaining a date of 1946 ± 6 (1 s, n = 9) for the genuine stamps, and 1963 ± 16 (1 s, n = 19) for the various reproductions. PMID:26767642

  8. Attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopic analysis of regenerated bone

    NASA Astrophysics Data System (ADS)

    Benetti, Carolina; Kazarain, Sergei G.; Alves, Marco A. V.; Blay, Alberto; Correa, Luciana; Zezell, Denise M.

    2014-03-01

    The cutting of bone is routinely required in medical procedures, especially in dental applications. In such cases, bone regeneration and new bone quality can determine the success of the treatment. This study investigated the main spectral differences of undamaged and healed bone using the ATR-FTIR spectroscopy technique. Three rabbits were submitted to a surgical procedure; a small piece of bone (3x3 mm2) was removed from both sides of their jaws using a high speed drill. After 15 days, the rabbits were euthanized and the jaws were removed. A bone slice was cut from each side of the jaw containing regions of undamaged and newly formed bone, resulting in six samples which were polished for spectroscopic comparison. The samples were analyzed by FTIR spectroscopy using a diamond ATR accessory. Spectral characteristics were compared and particular attention was paid to the proportion of phosphate to amide I bands and the width of the phosphate band. The results show that the ratio of phosphate to amide I is smaller in new bone tissue than in the undamaged bone, indicating a higher organic content in the newly formed bone. The analysis of the width of the phosphate band suggests a crystallinity difference between both tissues, since the width was higher in the new bone than in the natural bone. These results suggest that the differences observed in bone aging processes by FTIR spectroscopic can be applied to the study of healing processes.

  9. Attenuated total reflection-Fourier transform infrared spectroscopic imaging of pharmaceuticals in microfluidic devices.

    PubMed

    Ewing, Andrew V; Clarke, Graham S; Kazarian, Sergei G

    2016-03-01

    The poor aqueous solubility of many active pharmaceutical ingredients presents challenges for effective drug delivery. In this study, the combination of attenuated total reflection (ATR)-FTIR spectroscopic imaging with specifically designed polydimethylsiloxane microfluidic devices to study drug release from pharmaceutical formulations has been developed. First, the high-throughput analysis of the dissolution of micro-formulations studied under flowing conditions has been introduced using a model formulation of ibuprofen and polyethylene glycol. The behaviour and release of the drug was monitored in situ under different pH conditions. In contrast to the neutral solution, where both the drug and excipient dissolved at a similar rate, structural change from the molecularly dispersed to a crystalline form of ibuprofen was characterised in the obtained spectroscopic images and the corresponding ATR-FTIR spectra for the experiments carried out in the acidic medium. Further investigations into the behaviour of the drug after its release from formulations (i.e., dissolved drug) were also undertaken. Different solutions of sodium ibuprofen dissolved in a neutral medium were studied upon contact with acidic conditions. The phase transition from a dissolved species of sodium ibuprofen to the formation of solid crystalline ibuprofen was revealed in the microfluidic channels. This innovative approach could offer a promising platform for high-throughput analysis of a range of micro-formulations, which are of current interest due to the advent of 3D printed pharmaceutical and microparticulate delivery systems. Furthermore, the ability to study dissolved drug in solution under flowing conditions can be useful for the studies of the diffusion of drugs into tissues or live cells. PMID:27158293

  10. Rapid identification and classification of Staphylococcus aureus by attenuated total reflectance fourier transform infrared spectroscopy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Staphylococcus aureus is an important bacterium that can cause serious infections in humans such as pneumonia and bacteremia. Rapid detection of this pathogen is crucial in food industries and clinical laboratories to control S. aureus food poisoning and human infections. In this study, fourier tran...

  11. Compositional features of cotton plant biomass fractions characterized by attenuated total reflection Fourier transform infrared spectroscopy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cotton is one of the most important and widely grown crops in the world. In addition to natural textile fiber production as a primary purpose, it yields a high grade vegetable oil for human consumption and also carbohydrate fiber and protein byproducts for animal feed. In this work, attenuated total...

  12. Phosphorylation-induced conformational changes of cystic fibrosis transmembrane conductance regulator monitored by attenuated total reflection-Fourier transform IR spectroscopy and fluorescence spectroscopy.

    PubMed

    Grimard, Vinciane; Li, Canhui; Ramjeesingh, Mohabir; Bear, Christine E; Goormaghtigh, Erik; Ruysschaert, Jean-Marie

    2004-02-13

    Cystic fibrosis transmembrane conductance regulator (CFTR) is a member of the ABC protein superfamily. Phosphorylation of a regulatory domain of this protein is a prerequisite for activity. We analyzed the effect of protein kinase A (PKA) phosphorylation on the structure of purified and reconstituted CFTR protein. 1H/2H exchange monitored by attenuated total reflection Fourier transform IR spectroscopy demonstrates that CFTR is highly accessible to aqueous medium. Phosphorylation of the regulatory (R) domain by PKA further increases this accessibility. More specifically, fluorescence quenching of cytosolic tryptophan residues revealed that the accessibility of the cytoplasmic part of the protein is modified by phosphorylation. Moreover, the combination of polarized IR spectroscopy with 1H/2H exchange suggested an increase of the accessibility of the transmembrane domains of CFTR. This suggests that CFTR phosphorylation can induce a large conformational change that could correspond either to a displacement of the R domain or to long range conformational changes transmitted from the phosphorylation sites to the nucleotide binding domains and the transmembrane segments. Such structural changes may provide better access for the solutes to the nucleotide binding domains and the ion binding site.

  13. Development of secondary cell wall in cotton fibers as examined with Fourier transform-infrared spectroscopy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Our presentation will focus on continuing efforts to examine secondary cell wall development in cotton fibers using infrared Spectroscopy. Cotton fibers harvested at 18, 20, 24, 28, 32, 36 and 40 days after flowering were examined using attenuated total reflection Fourier transform-infrared (ATR FT-...

  14. Botanical trash mixtures analyzed with near-infrared and attenuated total reflectance fourier transform spectroscopy and thermogravimetric analysis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Botanical cotton trash mixed with lint reduces cotton’s marketability and appearance. During cotton harvesting, ginning, and processing, trash size reduction occurs, thus complicating its removal and identification. This trash causes problems by increasing ends down in yarn formation and thus proce...

  15. Surface Inspection using fourier transform infrared spectroscopy

    SciTech Connect

    Powell, G.L.; Smyrl, N.R.; Williams, D.M.; Meyers, H.M. III; Barber, T.E.; Marrero-Rivera, M.

    1994-08-08

    The use of reflectance Fourier transform infrared (FTIR) spectroscopy as a tool for surface inspection is described. Laboratory instruments and portable instruments can support remote sensing probes that can map chemical contaminants on surfaces. Detection limits under the best of conditions are in the subnanometer range (i.e., near absolute cleanliness), excellent performance is obtained in the submicrometer range, and useful performance may exist for films tens of microns thick. Identifying and quantifying contamination such as mineral oils and greases, vegetable oils, and silicone oils on aluminum foil, galvanized sheet steel, smooth aluminum tubing, and gritblasted 7075 aluminum alloy and D6AC steel are described. The ability to map in time and space the distribution of oil stains on metals is demonstrated. Techniques for quantitatively applying oils to metals, subsequently verifying the application, and nonlinear relationships between reflectance and the quantity of oil are discussed.

  16. Fourier transform infrared spectroscopy

    SciTech Connect

    Ferraro, J.R.; Basile, L.J.

    1985-01-01

    The final and largest volume to complete this four-volume treatise is published in response to the intense commercial and research interest in Fourier Transform Interferometry. Volume 4 introduces new information on, for example, applications of Diffuse Reflectance Spectroscopy in the Far-infrared Region. The editors place emphasis on surface studies and address advances in Capillary Gas Chromatography-Fourier Transform Interferometry.

  17. Structural effects of insulin-loading into HII mesophases monitored by electron paramagnetic resonance (EPR), small angle X-ray spectroscopy (SAXS), and attenuated total reflection Fourier transform spectroscopy (ATR-FTIR).

    PubMed

    Mishraki, Tehila; Ottaviani, Maria Francesca; Shames, Alexander I; Aserin, Abraham; Garti, Nissim

    2011-06-30

    Insulin entrapment within a monoolein-based reverse hexagonal (H(II)) mesophase was investigated under temperature-dependent conditions at acidic (pH 3) and basic (pH 8) conditions. Studying the structure of the host H(II) system and the interactions of insulin under temperature-dependent conditions has great impact on the enhancement of its thermal stabilization and controlled release for the purposes of transdermal delivery. Small angle X-ray spectroscopy (SAXS) measurements show that pH variation and/or insulin entrapment preserve the hexagonal structure and do not influence the lattice parameter. Attenuated total reflection Fourier transform spectroscopy (ATR-FTIR) spectra indicate that, although insulin interacts with hydroxyl groups of GMO in the interface region, it is not affected by pH variations. Hence different microenvironments within the H(II) mesophase were monitored by a computer-aided electron paramagnetic resonance (EPR) analysis using 5-doxylstearic acid (5-DSA) as a pH-dependent probe. The microviscosity, micropolarity, order of systems, and distribution of the probes in different microenvironments were influenced by three factors: temperature, pH, and insulin solubilization. When the temperature is increased, microviscosity and order parameters decreased at both pH 3 and 8, presenting different decrease trends. It was found that, at pH 3, the protein perturbs the lipid structure while "pushing aside" the un-ionized 5-DSA probe to fit into the narrow water cylinders. At the interface region (pH 8), the probe was distributed in two differently structured environments that significantly modifies by increasing temperature. Insulin loading within the H(II) mesophase decreased the order and microviscosity of both the microenvironments and increased their micropolarity. Finally, the EPR analysis also provides information about the unfolding/denaturation of insulin within the channel at high temperatures.

  18. Static Fourier transform infrared spectrometer.

    PubMed

    Schardt, Michael; Murr, Patrik J; Rauscher, Markus S; Tremmel, Anton J; Wiesent, Benjamin R; Koch, Alexander W

    2016-04-01

    Fourier transform spectroscopy has established itself as the standard method for spectral analysis of infrared light. Here we present a robust and compact novel static Fourier transform spectrometer design without any moving parts. The design is well suited for measurements in the infrared as it works with extended light sources independent of their size. The design is experimentally evaluated in the mid-infrared wavelength region between 7.2 μm and 16 μm. Due to its large etendue, its low internal light loss, and its static design it enables high speed spectral analysis in the mid-infrared.

  19. Application of Attenuated Total Reflectance-Fourier Transformed Infrared (ATR-FTIR) Spectroscopy To Determine the Chlorogenic Acid Isomer Profile and Antioxidant Capacity of Coffee Beans.

    PubMed

    Liang, Ningjian; Lu, Xiaonan; Hu, Yaxi; Kitts, David D

    2016-01-27

    The chlorogenic acid isomer profile and antioxidant activity of both green and roasted coffee beans are reported herein using ATR-FTIR spectroscopy combined with chemometric analyses. High-performance liquid chromatography (HPLC) quantified different chlorogenic acid isomer contents for reference, whereas ORAC, ABTS, and DPPH were used to determine the antioxidant activity of the same coffee bean extracts. FTIR spectral data and reference data of 42 coffee bean samples were processed to build optimized PLSR models, and 18 samples were used for external validation of constructed PLSR models. In total, six PLSR models were constructed for six chlorogenic acid isomers to predict content, with three PLSR models constructed to forecast the free radical scavenging activities, obtained using different chemical assays. In conclusion, FTIR spectroscopy, coupled with PLSR, serves as a reliable, nondestructive, and rapid analytical method to quantify chlorogenic acids and to assess different free radical-scavenging capacities in coffee beans. PMID:26725502

  20. Application of Attenuated Total Reflectance-Fourier Transformed Infrared (ATR-FTIR) Spectroscopy To Determine the Chlorogenic Acid Isomer Profile and Antioxidant Capacity of Coffee Beans.

    PubMed

    Liang, Ningjian; Lu, Xiaonan; Hu, Yaxi; Kitts, David D

    2016-01-27

    The chlorogenic acid isomer profile and antioxidant activity of both green and roasted coffee beans are reported herein using ATR-FTIR spectroscopy combined with chemometric analyses. High-performance liquid chromatography (HPLC) quantified different chlorogenic acid isomer contents for reference, whereas ORAC, ABTS, and DPPH were used to determine the antioxidant activity of the same coffee bean extracts. FTIR spectral data and reference data of 42 coffee bean samples were processed to build optimized PLSR models, and 18 samples were used for external validation of constructed PLSR models. In total, six PLSR models were constructed for six chlorogenic acid isomers to predict content, with three PLSR models constructed to forecast the free radical scavenging activities, obtained using different chemical assays. In conclusion, FTIR spectroscopy, coupled with PLSR, serves as a reliable, nondestructive, and rapid analytical method to quantify chlorogenic acids and to assess different free radical-scavenging capacities in coffee beans.

  1. Label-Free Determination of Protein Binding in Aqueous Solution using Overlayer Enhanced Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (OE-ATR-FTIR)

    NASA Astrophysics Data System (ADS)

    Ruthenburg, Travis; Aweda, Tolulope; Park, Simon; Meares, Claude; Land, Donald

    2009-03-01

    Protein binding/affinity studies are often performed using Surface Plasmon Resonance techniques that don't produce much spectral information. Measurement of protein binding affinity using FTIR is traditionally performed using high protein concentration or deuterated solvent. By immobilizing a protein near the surface of a gold-coated germanium internal reflection element interactions can be measured between an immobilized protein and free proteins or small molecules in aqueous solution. By monitoring the on and off rates of these interactions, the dissociation constant for the system can be determined. The dissociation constant for the molecule Yttrium-DOTA binding to the antibody 2D12.5 system was determined to be 100nM. Results will also be presented from our measurements of Bovine Serum Albumin (BSA) binding to anti-BSA.

  2. Prepreg cure monitoring using diffuse reflectance-FTIR. [Fourier Transform Infrared Technique

    NASA Technical Reports Server (NTRS)

    Young, P. R.; Chang, A. C.

    1984-01-01

    An in situ diffuse reflectance-Fourier transform infrared technique was developed to determine infrared spectra of graphite fiber prepregs as they were being cured. A bismaleimide, an epoxy, and addition polyimide matrix resin prepregs were studied. An experimental polyimide adhesive was also examined. Samples were positioned on a small heater at the focal point of diffuse reflectance optics and programmed at 15 F/min while FTIR spectra were being scanned, averaged, and stored. An analysis of the resulting spectra provided basic insights into changes in matrix resin molecular structure which accompanied reactions such as imidization and crosslinking. An endo-exothermal isomerization involving reactive end-caps was confirmed for the addition polyimide prepregs. The results of this study contribute to a fundamental understanding of the processing of composites and adhesives. Such understanding will promote the development of more efficient cure cycles.

  3. Authentication of canned fish packing oils by means of Fourier transform infrared spectroscopy.

    PubMed

    Dominguez-Vidal, Ana; Pantoja-de la Rosa, Jaime; Cuadros-Rodríguez, Luis; Ayora-Cañada, María José

    2016-01-01

    The authentication of packing oil from commercial canned tuna and other tuna-like fish species was examined by means of attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) and chemometrics. Using partial least squares discriminant analysis (PLS-DA), it was possible to differentiate olive oil from seed oils. Discrimination of olive oil from high-oleic sunflower oil was possible, despite the latter having a degree of unsaturation more similar to olive oil than to sunflower oil. However, in the samples analyzed, sunflower oil could not be differentiated clearly from those labeled with the generic term "vegetable oil". Furthermore, the authentication of extra virgin olive oil, although more difficult, could be achieved using ATR-FTIR spectroscopy. The method could be applied regardless of fish type, without interference from fish lipids.

  4. Authentication of canned fish packing oils by means of Fourier transform infrared spectroscopy.

    PubMed

    Dominguez-Vidal, Ana; Pantoja-de la Rosa, Jaime; Cuadros-Rodríguez, Luis; Ayora-Cañada, María José

    2016-01-01

    The authentication of packing oil from commercial canned tuna and other tuna-like fish species was examined by means of attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) and chemometrics. Using partial least squares discriminant analysis (PLS-DA), it was possible to differentiate olive oil from seed oils. Discrimination of olive oil from high-oleic sunflower oil was possible, despite the latter having a degree of unsaturation more similar to olive oil than to sunflower oil. However, in the samples analyzed, sunflower oil could not be differentiated clearly from those labeled with the generic term "vegetable oil". Furthermore, the authentication of extra virgin olive oil, although more difficult, could be achieved using ATR-FTIR spectroscopy. The method could be applied regardless of fish type, without interference from fish lipids. PMID:26212950

  5. Noninvasive biochemical monitoring of physiological stress by Fourier transform infrared saliva spectroscopy.

    PubMed

    Khaustova, Svetlana; Shkurnikov, Maxim; Tonevitsky, Evgeny; Artyushenko, Viacheslav; Tonevitsky, Alexander

    2010-12-01

    Physical stress affects the immune system, activates the sympathetic (SNS) and parasympathetic (PNS) subsystems of autonomic nervous system (ANS), and increases the activity of the hypothalamic-pituitary-adrenal axis (HPA). The specific response of the major regulatory systems depends on the human functional state. Saliva is a unique diagnostic fluid, the composition of which immediately reflects the SNS, PNS, HPA and immune system response to stress. A new method of saliva biomarker determination by Attenuated Total Reflection Fourier-Transform Infrared (ATR FTIR) spectroscopy has been developed to monitor the exercise induced metabolic changes in saliva from male endurance athletes. The method has been tested using a group of professional athletes by analysing saliva samples collected before and after the exercise, and the saliva composition monitoring by ATR FTIR spectroscopy was shown to be suitable for real-time checking of response to stress.

  6. Livermore Imaging Fourier Transform Infrared Spectrometer (LIFTIRS)

    SciTech Connect

    Carter, M.R.; Bennett, C.L.; Fields, D.J.; Lee, F.D.

    1995-05-10

    Lawrence Livermore National Laboratory is currently operating a hyperspectral imager, the Livermore Imaging Fourier Transform Infrared Spectrometer (LIFTIRS). This instrument is capable of operating throughout the infrared spectrum from 3 to 12.5 {mu}m with controllable spectral resolution. In this presentation we report on it`s operating characteristics, current capabilities, data throughput and calibration issues.

  7. Mid-Infrared and Near Infrared Calibrations for Nutritional Parameters of Triticale (Triticosecale) and Pea (Pisum sativum)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Data is lacking about the relative effectiveness of diffuse reflectance Fourier transformed mid-infrared (MidIR) versus near infrared (NIR) spectroscopy for calibration development of forage constituents. The objective of this study was to develop MidIR and NIR calibrations for acid detergent fiber ...

  8. Fourier-Transform Infrared Spectrometer

    NASA Technical Reports Server (NTRS)

    Schindler, R. A.

    1986-01-01

    Fourier-transform spectrometer provides approximately hundredfold increase in luminosity at detector plane over that achievable with older instruments of this type. Used to analyze such weak sources as pollutants and other low-concentration substances in atmosphere. Interferometer creates fringe patterns on two distinct arrays of light detectors, which observe different wavelength bands. Objective lens focuses scene on image plane, which contains optical chopper. To make instrument less susceptible to variations in scene under observation, field and detector lenses focus entrance aperture, rather that image, onto detector array.

  9. Fourier transform infrared imaging of bone.

    PubMed

    Paschalis, Eleftherios P

    2012-01-01

    Fourier transform infrared imaging (FTIRI) is a technique that can be used to analyze the material properties of bone using tissue sections. In this chapter I describe the basic principles of FTIR and the methods for capturing and analyzing FTIR images in bone sections.

  10. Fourier transform infrared spectrometery: an undergraduate experiment

    NASA Astrophysics Data System (ADS)

    Lerner, L.

    2016-11-01

    Simple apparatus is developed, providing undergraduate students with a solid understanding of Fourier transform (FT) infrared (IR) spectroscopy in a hands on experiment. Apart from its application to measuring the mid-IR spectra of organic molecules, the experiment introduces several techniques with wide applicability in physics, including interferometry, the FT, digital data analysis, and control theory.

  11. An evaluation of Fourier transforms infrared spectroscopy method for the classification and discrimination of bovine, porcine and fish gelatins.

    PubMed

    Cebi, Nur; Durak, M Zeki; Toker, Omer Said; Sagdic, Osman; Arici, Muhammet

    2016-01-01

    The objective of this research was to develop a rapid spectroscopic technique as an alternative method for the differentiation and authentication of gelatin sources in food products by using attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectra combined with chemometrics. Clear discrimination and classification of all the studied gelatin sources (bovine, porcine, and fish) were achieved by hierarchical cluster and principle component analysis (PCA). Amide-I (1700-1600 cm(-1)) and Amide-II (1565-1520 cm(-1)) spectral bands were used in a chemometric method. Moreover, ATR-FTIR spectral data successfully discriminated pure bovine gelatin from mixture of bovine and porcine gelatins, which is very important for the food industry. The method that we adopted could be beneficial for rapid, simple and economic determination of both gelatin presence and its origin from food products such as yogurt, ice cream, milk dessert or other gelatin containing products such as pharmaceuticals and cosmetics.

  12. Authentication of yerba mate according to the country of origin by using Fourier transform infrared (FTIR) associated with chemometrics.

    PubMed

    Marcelo, Marcelo C A; Pozebon, Dirce; Ferrão, Marco F

    2015-01-01

    This study deals with the development of a method for classification of yerba mate (Ilex paraguariensis) using attenuated total-reflectance Fourier transform infrared (ATR-FTIR) and multivariate analysis. Fifty-four brands of yerba mate from southern South America were analysed in order to classify the commercialised yerba mate according to the respective country of yerba mate processing. The yerba mate was ground in a cryogenic mill, and the reflectance was directly measured in the region ranging from 4000 to 650 cm(-1). Different pre-processing algorithms and three methods of multivariate analysis were investigated, including principal component analysis (PCA), partial least square discriminant analysis (PLS-DA) and support vector machine discriminant analysis (SVM-DA). The yerba mate classification was 100% correct when the reflectance spectra were pre-treated (derived at first order, normalised by standard normal variation, smoothed and mean centred) and analysed using the SVM-DA method.

  13. Fourier transform infrared spectroscopy for Mars science

    NASA Astrophysics Data System (ADS)

    Anderson, Mark S.; Andringa, Jason M.; Carlson, Robert W.; Conrad, Pamela; Hartford, Wayne; Shafer, Michael; Soto, Alejandro; Tsapin, Alexandre I.; Dybwad, Jens Peter; Wadsworth, Winthrop; Hand, Kevin

    2005-03-01

    Presented here is a Fourier transform infrared spectrometer (FTIR) for field studies that serves as a prototype for future Mars science applications. Infrared spectroscopy provides chemical information that is relevant to a number of Mars science questions. This includes mineralogical analysis, nitrogen compound recognition, truth testing of remote sensing measurements, and the ability to detect organic compounds. The challenges and scientific opportunities are given for the in situ FTIR analysis of Mars soil and rock samples. Various FTIR sampling techniques are assessed and compared to other analytical instrumentation. The prototype instrument presented is capable of providing field analysis in a Mars analog Antarctic environment. FTIR analysis of endolithic microbial communities in Antarctic rocks and a Mars meteor are given as analytical examples.

  14. Use of attenuated total reflection Fourier transform infrared (ATR FT-IR) spectroscopy in direct, non-destructive, and rapid assessment of developmental cotton fibers grown in planta and in culture

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cotton fibers are routinely harvested from cotton plants (in planta), and their end-use qualities depend on their development stages. Cotton fibers are also cultured at controlled laboratory environments, so that cotton researchers can investigate many aspects of experimental protocols in cotton bre...

  15. Ectomycorrhizal identification in environmental samples of tree roots by Fourier-transform infrared (FTIR) spectroscopy

    PubMed Central

    Pena, Rodica; Lang, Christa; Naumann, Annette; Polle, Andrea

    2014-01-01

    Roots of forest trees are associated with various ectomycorrhizal (ECM) fungal species that are involved in nutrient exchange between host plant and the soil compartment. The identification of ECM fungi in small environmental samples is difficult. The present study tested the feasibility of attenuated total reflection Fourier-transform infrared (ATR-FTIR) spectroscopy followed by hierarchical cluster analysis (HCA) to discriminate in situ collected ECM fungal species. Root tips colonized by distinct ECM fungal species, i.e., Amanita rubescens, Cenococcum geophilum, Lactarius subdulcis, Russula ochroleuca, and Xerocomus pruinatus were collected in mono-specific beech (Fagus sylvatica) and mixed deciduous forests in different geographic areas to investigate the environmental variability of the ECM FTIR signatures. A clear HCA discrimination was obtained for ECM fungal species independent of individual provenance. Environmental variability neither limited the discrimination between fungal species nor provided sufficient resolution to discern species sub-clusters for different sites. However, the de-convoluted FTIR spectra contained site-related spectral information for fungi with wide nutrient ranges, but not for Lactarius subdulcis, a fungus residing only in the litter layer. Specific markers for distinct ECM were identified in spectral regions associated with carbohydrates (i.e., mannans), lipids, and secondary protein structures. The present results support that FTIR spectroscopy coupled with multivariate analysis is a reliable and fast method to identify ECM fungal species in minute environmental samples. Moreover, our data suggest that the FTIR spectral signatures contain information on physiological and functional traits of ECM fungi. PMID:24904624

  16. Fourier-transform infrared spectroscopy for rapid screening and live-cell monitoring: application to nanotoxicology

    SciTech Connect

    Sundaram, S. K.; Sacksteder, Colette A.; Weber, T. J.; Riley, Brian J.; Addleman, Raymond S.; Harrer, Bruce J.; Peterman, John W.

    2013-01-01

    A significant challenge to realize the full potential of nanotechnology for therapeutic and diagnostic applications is to understand and evaluate how live-cells interact with an external stimulus, e.g., a nanosized particle (NSP), and the toxicity and broad risk associated with these stimuli. NSPs are increasingly used in medicine with largely undetermined hazards in complex cell dynamics and environments. It is difficult to capture the complexity and dynamics of these interactions by following an omics-based approach exclusively, which are expensive and time-consuming. Additionally, this approach needs destructive sampling methods. Live-cell attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectrometry is well suited to provide noninvasive approach to provide rapid screening of cellular responses to potentially toxic NSPs or any stimuli. Herein we review the technical basis of the approach, the instrument configuration and interface with the biological media, and various effects that impact the data, data analysis, and toxicity. Our preliminary results on live-cell monitoring show promise for rapid screening the NSPs.

  17. Ectomycorrhizal identification in environmental samples of tree roots by Fourier-transform infrared (FTIR) spectroscopy.

    PubMed

    Pena, Rodica; Lang, Christa; Naumann, Annette; Polle, Andrea

    2014-01-01

    Roots of forest trees are associated with various ectomycorrhizal (ECM) fungal species that are involved in nutrient exchange between host plant and the soil compartment. The identification of ECM fungi in small environmental samples is difficult. The present study tested the feasibility of attenuated total reflection Fourier-transform infrared (ATR-FTIR) spectroscopy followed by hierarchical cluster analysis (HCA) to discriminate in situ collected ECM fungal species. Root tips colonized by distinct ECM fungal species, i.e., Amanita rubescens, Cenococcum geophilum, Lactarius subdulcis, Russula ochroleuca, and Xerocomus pruinatus were collected in mono-specific beech (Fagus sylvatica) and mixed deciduous forests in different geographic areas to investigate the environmental variability of the ECM FTIR signatures. A clear HCA discrimination was obtained for ECM fungal species independent of individual provenance. Environmental variability neither limited the discrimination between fungal species nor provided sufficient resolution to discern species sub-clusters for different sites. However, the de-convoluted FTIR spectra contained site-related spectral information for fungi with wide nutrient ranges, but not for Lactarius subdulcis, a fungus residing only in the litter layer. Specific markers for distinct ECM were identified in spectral regions associated with carbohydrates (i.e., mannans), lipids, and secondary protein structures. The present results support that FTIR spectroscopy coupled with multivariate analysis is a reliable and fast method to identify ECM fungal species in minute environmental samples. Moreover, our data suggest that the FTIR spectral signatures contain information on physiological and functional traits of ECM fungi.

  18. Rapid Isolation of Phenol Degrading Bacteria by Fourier Transform Infrared (FTIR) Spectroscopy.

    PubMed

    Li, Fei; Song, Wen-jun; Wei, Ji-ping; Wang, Su-ying; Liu, Chong-ji

    2015-05-01

    Phenol is an important chemical engineering material and ubiquitous in industry wastewater, its existence has become a thorny issue in many developed and developing country. More and more stringent standards for effluent all over the world with human realizing the toxicity of phenol have been announced. Many advanced biological methods are applied to industrial wastewater treatment with low cost, high efficiency and no secondary pollution, but the screening of function microorganisms is certain cumbersome process. In our study a rapid procedure devised for screening bacteria on solid medium can degrade phenol coupled with attenuated total reflection fourier transform infrared (ATR-FTIR) which is a detection method has the characteristics of efficient, fast, high fingerprint were used. Principal component analysis (PCA) is a method in common use to extract fingerprint peaks effectively, it couples with partial least squares (PLS) statistical method could establish a credible model. The model we created using PCA-PLS can reach 99. 5% of coefficient determination and validation data get 99. 4%, which shows the promising fitness and forecasting of the model. The high fitting model is used for predicting the concentration of phenol at solid medium where the bacteria were grown. The highly consistent result of two screening methods, solid cultural with ATR-FTIR detected and traditional liquid cultural detected by GC methods, suggests the former can rapid isolate the bacteria which can degrade substrates as well as traditional cumbersome liquid cultural method. Many hazardous substrates widely existed in industry wastewater, most of them has specialize fingerprint peaks detected by ATR-FTIR, thereby this detected method could be used as a rapid detection for isolation of functional microorganisms those can degrade many other toxic substrates.

  19. Fourier Transform Infrared Spectroscopy Part III. Applications.

    ERIC Educational Resources Information Center

    Perkins, W. D.

    1987-01-01

    Discusses the use of the FT-IR spectrometer in analyses that were previously avoided. Examines some of the applications of this spectroscopy with aqueous solutions, circular internal reflection, samples with low transmission, diffuse reflectance, infrared emission, and the infrared microscope. (TW)

  20. Fourier Transforms Simplified: Computing an Infrared Spectrum from an Interferogram

    ERIC Educational Resources Information Center

    Hanley, Quentin S.

    2012-01-01

    Fourier transforms are used widely in chemistry and allied sciences. Examples include infrared, nuclear magnetic resonance, and mass spectroscopies. A thorough understanding of Fourier methods assists the understanding of microscopy, X-ray diffraction, and diffraction gratings. The theory of Fourier transforms has been presented in this "Journal",…

  1. Diagnostic segregation of human brain tumours using Fourier-transform infrared and/or Raman spectroscopy coupled with discriminant analysis†

    PubMed Central

    Gajjar, Ketan; Heppenstall, Lara D.; Pang, Weiyi; Ashton, Katherine M.; Trevisan, Júlio; Patel, Imran I.; Llabjani, Valon; Stringfellow, Helen F.; Martin-Hirsch, Pierre L.; Dawson, Timothy; Martin, Francis L.

    2013-01-01

    The most common initial treatment received by patients with a brain tumour is surgical removal of the growth. Precise histopathological diagnosis of brain tumours is to some extent subjective. Furthermore, currently available diagnostic imaging techniques to delineate the excision border during cytoreductive surgery lack the required spatial precision to aid surgeons. We set out to determine whether infrared (IR) and/or Raman spectroscopy combined with multivariate analysis could be applied to discriminate between normal brain tissue and different tumour types (meningioma, glioma and brain metastasis) based on the unique spectral “fingerprints” of their biochemical composition. Formalin-fixed paraffin-embedded tissue blocks of normal brain and different brain tumours were de-waxed, mounted on low-E slides and desiccated before being analyzed using attenuated total reflection Fourier-transform IR (ATR-FTIR) and Raman spectroscopy. ATR-FTIR spectroscopy showed a clear segregation between normal and different tumour subtypes. Discrimination of tumour classes was also apparent with Raman spectroscopy. Further analysis of spectral data revealed changes in brain biochemical structure associated with different tumours. Decreased tentatively-assigned lipid-to-protein ratio was associated with increased tumour progression. Alteration in cholesterol esters-to-phenylalanine ratio was evident in grade IV glioma and metastatic tumours. The current study indicates that IR and/or Raman spectroscopy have the potential to provide a novel diagnostic approach in the accurate diagnosis of brain tumours and have potential for application in intra-operative diagnosis. PMID:24098310

  2. Quantitative determination of fatty acid compositions in micro-encapsulated fish-oil supplements using Fourier transform infrared (FTIR) spectroscopy.

    PubMed

    Vongsvivut, Jitraporn; Heraud, Philip; Zhang, Wei; Kralovec, Jaroslav A; McNaughton, Don; Barrow, Colin J

    2012-11-15

    The research describes a rapid method for the determination of fatty acid (FA) contents in a micro-encapsulated fish-oil (μEFO) supplement by using attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopic technique and partial least square regression (PLSR) analysis. Using the ATR-FTIR technique, the μEFO powder samples can be directly analysed without any pre-treatment required, and our developed PLSR strategic approach based on the acquired spectral data led to production of a good linear calibration with R(2)=0.99. In addition, the subsequent predictions acquired from an independent validation set for the target FA compositions (i.e., total oil, total omega-3 fatty acids, EPA and DHA) were highly accurate when compared to the actual values obtained from standard GC-based technique, with plots between predicted versus actual values resulting in excellent linear fitting (R(2)≥0.96) in all cases. The study therefore demonstrated not only the substantial advantage of the ATR-FTIR technique in terms of rapidness and cost effectiveness, but also its potential application as a rapid, potentially automated, online monitoring technique for the routine analysis of FA composition in industrial processes when used together with the multivariate data analysis modelling.

  3. Fourier transform infrared spectroscopy of deuterated proteins

    NASA Astrophysics Data System (ADS)

    Marcano O., A.; Markushin, Y.; Melikechi, N.; Connolly, D.

    2008-08-01

    We report on Fourier transform spectra of deuterated proteins: Bovine Serum Albumin, Leptin, Insulin-like Growth Factor II, monoclonal antibody to ovarian cancer antigen CA125 and Osteopontin. The spectra exhibit changes in the relative amplitude and spectral width of certain peaks. New peaks not present in the non-deuterated sample are also observed. Ways for improving the deuteration of proteins by varying the temperature and dilution time are discussed. We propose the use of deuterated proteins to increase the sensitivity of immunoassays aimed for early diagnostic of diseases most notably cancer.

  4. Analysis of Counterfeit Coated Tablets and Multi-Layer Packaging Materials Using Infrared Microspectroscopic Imaging.

    PubMed

    Winner, Taryn L; Lanzarotta, Adam; Sommer, André J

    2016-06-01

    An effective method for detecting and characterizing counterfeit finished dosage forms and packaging materials is described in this study. Using attenuated total internal reflection Fourier transform infrared spectroscopic imaging, suspect tablet coating and core formulations as well as multi-layered foil safety seals, bottle labels, and cigarette tear tapes were analyzed and compared directly with those of a stored authentic product. The approach was effective for obtaining molecular information from structures as small as 6 μm.

  5. Analysis of Counterfeit Coated Tablets and Multi-Layer Packaging Materials Using Infrared Microspectroscopic Imaging.

    PubMed

    Winner, Taryn L; Lanzarotta, Adam; Sommer, André J

    2016-06-01

    An effective method for detecting and characterizing counterfeit finished dosage forms and packaging materials is described in this study. Using attenuated total internal reflection Fourier transform infrared spectroscopic imaging, suspect tablet coating and core formulations as well as multi-layered foil safety seals, bottle labels, and cigarette tear tapes were analyzed and compared directly with those of a stored authentic product. The approach was effective for obtaining molecular information from structures as small as 6 μm. PMID:27068491

  6. Fourier transform infrared spectroscopic analysis of cell differentiation

    NASA Astrophysics Data System (ADS)

    Ishii, Katsunori; Kimura, Akinori; Kushibiki, Toshihiro; Awazu, Kunio

    2007-02-01

    Stem cells and its differentiations have got a lot of attentions in regenerative medicine. The process of differentiations, the formation of tissues, has become better understood by the study using a lot of cell types progressively. These studies of cells and tissue dynamics at molecular levels are carried out through various approaches like histochemical methods, application of molecular biology and immunology. However, in case of using regenerative sources (cells, tissues and biomaterials etc.) clinically, they are measured and quality-controlled by non-invasive methods from the view point of safety. Recently, the use of Fourier Transform Infrared spectroscopy (FT-IR) has been used to monitor biochemical changes in cells, and has gained considerable importance. The objective of this study is to establish the infrared spectroscopy of cell differentiation as a quality control of cell sources for regenerative medicine. In the present study, as a basic study, we examined the adipose differentiation kinetics of preadipocyte (3T3-L1) and the osteoblast differentiation kinetics of bone marrow mesenchymal stem cells (Kusa-A1) to analyze the infrared absorption spectra. As a result, we achieved to analyze the adipose differentiation kinetics using the infrared absorption peak at 1739 cm-1 derived from ester bonds of triglyceride and osteoblast differentiation kinetics using the infrared absorption peak at 1030 cm-1 derived from phosphate groups of calcium phosphate.

  7. Fourier Transform Infrared Spectroscopy for Identification and Quantification of Organic Functional Groups in Aqueous Phase Secondary Organic Aerosol

    NASA Astrophysics Data System (ADS)

    George, K.; Ruthenburg, T. C.; Smith, J.; Anastasio, C.; Dillner, A. M.

    2011-12-01

    Particles in the atmosphere influence visibility, climate, and human health. Secondary organic aerosols (SOA) formed from chemical reactions in the atmosphere constitute a portion of total organic particle mass. Most research on SOA has focused on gas phase reactions; however, reactions taking place in cloud and fog drops may be significant. One group of water-soluble compounds that participate in these reactions is phenols. Phenols, emitted from biomass burning, react in the aqueous phase to form low-volatility SOA products. The products formed from these reactions are currently poorly characterized. In order to characterize laboratory-generated samples, we are developing an attenuated total reflectance-Fourier transform infrared spectroscopic (ATR-FTIR) technique to identify and quantify organic functional groups in SOA. Aqueous SOA is made in the laboratory by illuminating solutions of phenolic compounds with an oxidant. The illuminated solution is then blown to dryness in order to determine the mass of SOA produced. The dry SOA is reconstituted in water and drops of this solution are placed onto a single-reflection ATR accessory. In order to identify and quantify functional groups in the complex SOA samples, it is necessary to calibrate with compounds and mixtures of compounds containing bond types similar to those found in the laboratory-generated SOA. Initially, focus has been placed on multiple peaks located in the region between 1800 cm-1 and 800 cm-1, including peaks for C=O and C-O. We distinguish between characteristic absorbances to begin determining the organic functional group composition of the SOA samples. This ATR-FTIR technique complements information from mass spectrometry measurements and allows us to quantify organic mass for non-volatile SOA products.

  8. [Biological Process Oriented Online Fourier Transform Infrared Spectrometer].

    PubMed

    Xie, Fei; Wu, Qiong-shui; Zeng, Li-bo

    2015-08-01

    An online Fourier Transform Infrared Spectrometer and an ATR (Attenuated Total Reflection) probe, specifically at the application of real time measurement of the reaction substrate concentration in biological processes, were designed. (1) The spectrometer combined the theories of double cube-corner reflectors and flat mirror, which created a kind of high performance interferometer system. The light path folding way was utilized to makes the interferometer compact structure. Adopting double cube-corner reflectors, greatly reduces the influence of factors in the process of moving mirror movement such as rotation, tilt, etc. The parallelogram oscillation flexible support device was utilized to support the moving mirror moves. It cancelled the friction and vibration during mirror moving, and ensures the smooth operation. The ZnSe splitter significantly improved the hardware reliability in high moisture environment. The method of 60° entrance to light splitter improves the luminous flux. (2) An ATR in situ measuring probe with simple structure, large-flux, economical and practical character was designed in this article. The transmission of incident light and the light output utilized the infrared pipe with large diameter and innerplanted-high plating membrane, which conducted for the infrared transmission media of ATR probe. It greatly reduced the energy loss of infrared light after multiple reflection on the inner wall of the light pipe. Therefore, the ATR probe obtained high flux, improved the signal strength, which make the signal detected easily. Finally, the high sensitivity of MCT (Mercury Cadmium Telluride) detector was utilized to realize infrared interference signal collection, and improved the data quality of detection. The test results showed that the system yields the advantages of perfect moisture-proof performance, luminous flux, online measurement, etc. The designed online Fourier infrared spectrometer can real-time measured common reactant substrates

  9. A high-resolution Fourier-transform infrared spectrometer.

    NASA Technical Reports Server (NTRS)

    Johnson, H. L.; Forbes, F. F.; Thompson, R. I.; Steinmetz , D. L.; Harris, O.

    1973-01-01

    We have developed a Fourier-transform infrared spectrometer having a resolution of 0.5/cm over the range of wavelength from 1 to 5.5 microns. It has been used to observe the sun over this wavelength range from a Lear Jet flying at an altitude of 14 km, and to observe a number of stars from the ground, using the 229-cm telescope of the Steward Observatory and the 152-cm aluminum-mirror telescope at the Observatorio Astronomico Nacional in the Sierra de San Pedro Martir, Baja California, Mexico. The solar spectrum is given here, while the ground-based spectra are being published separately.

  10. Homogeneous Nature of Malaysian Marine Fish Epinephelus fuscoguttatus (Perciformes; Serranidae): Evidence Based on Molecular Markers, Morphology and Fourier Transform Infrared Analysis.

    PubMed

    Nurdalila, A'wani Aziz; Bunawan, Hamidun; Kumar, Subbiah Vijay; Rodrigues, Kenneth Francis; Baharum, Syarul Nataqain

    2015-07-02

    Taxonomic confusion exists within the genus Epinephelus due to the lack of morphological specializations and the overwhelming number of species reported in several studies. The homogenous nature of the morphology has created confusion in the Malaysian Marine fish species Epinephelus fuscoguttatus and Epinephelus hexagonatus. In this study, the partial DNA sequence of the 16S gene and mitochondrial nucleotide sequences of two gene regions, Cytochrome Oxidase Subunit I and III were used to investigate the phylogenetic relationship between them. In the phylogenetic trees, E. fuscoguttatus was monophyletic with E. hexagonatus species and morphology examination shows that no significant differences were found in the morphometric features between these two taxa. This suggests that E. fuscoguttatus is not distinguishable from E. hexagonatus species, and that E. fuscoguttatus have been identified to be E. hexagonatus species is likely attributed to differences in environment and ability to camouflage themselves under certain conditions. Interestingly, this finding was also supported by Principal Component Analysis on Attenuated Total Reflectance-Fourier-transform Infrared (ATR-FTIR) data analysis. Molecular, morphological and meristic characteristics were combined with ATR-FTIR analysis used in this study offer new perspectives in fish species identification. To our knowledge, this is the first report of an extensive genetic population study of E. fuscoguttatus in Malaysia and this understanding will play an important role in informing genetic stock-specific strategies for the management and conservation of this highly valued fish.

  11. Development of attenuated total reflection based compression modulation step-scan Fourier transform infrared spectroscopy and its applications to rheo-spectral characterizations of polymer films.

    PubMed

    Nishikawa, Yuji; Nakano, Tatsuhiko; Miyauchi, Hiroshi; Nishikida, Koichi; Jiang, Eric Y

    2004-08-01

    Dynamic compression modulation attenuated total reflection Fourier transform infrared (ATR FT-IR) spectroscopic methods have been developed in this paper for characterizing polymer films. To obtain dynamic compression polarized ATR spectra, internal reflection element (IRE) secure assemblies made of tungsten carbide with very high hardness (Knoop hardness of > 1000 kgf/mm(2)) have been designed. These assemblies are mounted on the Harrick Seagull ATR attachment and measured by step-scan FT-IR spectroscopy. The effect of static compression, air gaps, and refractive index changes were examined. Experimental and simulated results showed that the effect of air gaps between the sample and IRE and refractive index changes of the sample and IRE are negligible at values larger than a static torque of 40 cN m and good signal-to-noise ratios (SNR) and reproducible data can be obtained. Uniaxially and biaxially drawn poly(ethylene terephthalate) films were measured by the presented method. Both bipolar and unipolar bands were observed in the dynamic in-phase ATR spectra, which can be associated with their micro-structural environmental changes. This technique shows promise in evaluating various polymer film materials, including biaxially oriented films, multilayer coated film surfaces, and molecular interactions between polymer-polymer and polymer-additives at the film surface.

  12. QUANTITATIVE FOURIER TRANSFORM INFRARED SPECTROSCOPIC INVESTIGATION OF HUMIC SUBSTANCE FUNCTIONAL GROUP COMPOSITION

    EPA Science Inventory

    Infrared (IR) spectroscopy has been widely used for the structural investigation of humic substances. Although Fourier Transform Infrared (FTIR) instrumentation has been available for sometime, relatively little work with these instruments has been reported for humic substances,...

  13. ENVIRONMENTAL ANALYSIS BY AB INITIO QUANTUM MECHANICAL COMPUTATION AND GAS CHROMATOGRAPHY/FOURIER TRANSFORM INFRARED SPECTROMETRY.

    EPA Science Inventory

    Computational chemistry, in conjunction with gas chromatography/mass spectrometry/Fourier transform infrared spectrometry (GC/MS/FT-IR), was used to tentatively identify seven tetrachlorobutadiene (TCBD) isomers detected in an environmental sample. Computation of the TCBD infrare...

  14. Discrimination of different Chrysanthemums with Fourier transform infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Liu, Hong-xia; Zhou, Qun; Sun, Su-qin; Bao, Hong-juan

    2008-07-01

    Use Fourier transform infrared spectroscopy (FT-IR) to analyze simultaneously the main chemical constituents in different solvent extracts of seven kinds of Chrysanthemum samples of different regions. The findings indicate that different Chrysanthemum samples have dissimilar fingerprint characters in FT-IR spectra. Such spectral technique can provide substance structural information of the complicated test samples. According to these spectral fingerprint features, we cannot only identify the main components of different extracts, but also distinguish the origins of the Chrysanthemum samples from different regions easily, which is a troublesome work by existing analytical methods. FT-IR, with the characters of speediness, good repeatability and easy operation, can be used as an effective analytical means to study the complicated system, in our research, the tradition Chinese medicines.

  15. A rheumatoid arthritis study by Fourier transform infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Carvalho, Carolina S.; Silva, Ana Carla A.; Santos, Tatiano J. P. S.; Martin, Airton A.; dos Santos Fernandes, Ana Célia; Andrade, Luís E.; Raniero, Leandro

    2012-01-01

    Rheumatoid arthritis is a systemic inflammatory disease of unknown causes and a new methods to identify it in early stages are needed. The main purpose of this work is the biochemical differentiation of sera between normal and RA patients, through the establishment of a statistical method that can be appropriately used for serological analysis. The human sera from 39 healthy donors and 39 rheumatics donors were collected and analyzed by Fourier Transform Infrared Spectroscopy. The results show significant spectral variations with p<0.05 in regions corresponding to protein, lipids and immunoglobulins. The technique of latex particles, coated with human IgG and monoclonal anti-CRP by indirect agglutination known as FR and CRP, was performed to confirm possible false-negative results within the groups, facilitating the statistical interpretation and validation of the technique.

  16. Fourier transform infrared phase shift cavity ring down spectrometer

    NASA Astrophysics Data System (ADS)

    Schundler, Elizabeth; Mansur, David J.; Vaillancourt, Robert; Benedict-Gill, Ryan; Newbry, Scott P.; Engel, James R.; Rentz Dupuis, Julia

    2013-05-01

    We report on our current status towards the development of a prototype Fourier transform infrared phase shift cavity ring down spectrometer (FTIR-PS-CRDS) system under a U.S. EPA SBIR contract. Our system uses the inherent wavelength-dependent modulation imposed by the FTIR on a broadband thermal source for the phase shift measurement. This spectrally-dependent phase shift is proportional to the spectrally-dependent ring down time, which is proportional to the losses of the cavity including those due to molecular absorption. Our approach is a broadband and spectral range enhancement to conventional CRDS which is typically done in the near IR at a single wavelength; at the same time our approach is a sensitivity enhancement to traditional FTIR owing to the long effective path of the resonant cavity. In this paper we present a summary of the theory including performance projections and the design details of the prototype FTIR-PS-CRDS system.

  17. Understanding coal using thermal decomposition and fourier transform infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Solomon, P. R.; Hamblen, D. G.

    1981-02-01

    Fourier Transform Infrared Spectroscopy (FTIR) is being used to provide understanding of the organic structure of coals and coal thermal decomposition products. The research has developed a relationship between the coal organic structure and the products of thermal decomposition. The work has also led to the discovery that many of the coal structural elements are preserved in the heavy molecular weight products (tar) released in thermal decomposition and that careful analysis of these products in relation to the parent coal can supply clues to the original structure. Quantitative FTIR spectra for coals, tars and chars are used to determine concentrations of the hydroxyl, aliphatic and aromatic hydrogen. Concentrations of aliphatic carbon are computed using an assumed aliphatic stoichiometry; aromatic carbon concentrations are determined by difference. The values are in good agreement with date determined by 13C and proton NMR. Analysis of the solid produ ts produced by successive stages in the thermal decomposition provides information on the changes in the chemical bonds occurring during the process. Time resolved infrared scans (129 msec/scan) taken during the thermal decomposition provide data on the amount, composition and rate of evolution of light gas species. The relationship between the evolved light species and their sources in the coal is developed by comparing the rate of evolution with the rate of change in the chemical bonds. With the application of these techniques, a general kinetic model has been developed which relates the products of thermal decomposition to the organic structure of the parent coal.

  18. Fourier transform infrared phase shift cavity ring down spectrometer

    NASA Astrophysics Data System (ADS)

    Schundler, Elizabeth; Mansur, David J.; Vaillancourt, Robert; Benedict-Gill, Ryan; Newbry, Scott P.; Engel, James R.; Dupuis, Julia Rentz

    2014-05-01

    OPTRA has developed a Fourier transform infrared phase shift cavity ring down spectrometer (FTIR-PS-CRDS) system under a U.S. EPA SBIR contract. This system uses the inherent wavelength-dependent modulation imposed by the FTIR on a broadband thermal source for the phase shift measurement. This spectrally-dependent phase shift is proportional to the spectrally-dependent ring down time. The spectral dependence of both of these values is introduced by the losses of the cavity including those due to the molecular absorption of the sample. OPTRA's approach allows broadband detection of chemicals across the feature-rich fingerprint region of the long-wave infrared. This represents a broadband and spectral range enhancement to conventional CRDS which is typically done at a single wavelength in the near IR; at the same time the approach is a sensitivity enhancement to traditional FTIR, owing to the long effective path of the resonant cavity. In previous papers1,2, OPTRA has presented a breadboard system aimed at demonstrating the feasibility of the approach and a prototype design implementing performance enhancements based on the results of breadboard testing. In this final paper in the series, we will present test results illustrating the realized performance of the fully assembled and integrated breadboard, thereby demonstrating the utility of the approach.

  19. Fourier transform infrared imaging and infrared fiber optic probe spectroscopy identify collagen type in connective tissues.

    PubMed

    Hanifi, Arash; McCarthy, Helen; Roberts, Sally; Pleshko, Nancy

    2013-01-01

    Hyaline cartilage and mechanically inferior fibrocartilage consisting of mixed collagen types are frequently found together in repairing articular cartilage. The present study seeks to develop methodology to identify collagen type and other tissue components using Fourier transform infrared (FTIR) spectral evaluation of matrix composition in combination with multivariate analyses. FTIR spectra of the primary molecular components of repair cartilage, types I and II collagen, and aggrecan, were used to develop multivariate spectral models for discrimination of the matrix components of the tissues of interest. Infrared imaging data were collected from bovine bone, tendon, normal cartilage, meniscus and human repair cartilage tissues, and composition predicted using partial least squares analyses. Histology and immunohistochemistry results were used as standards for validation. Infrared fiber optic probe spectral data were also obtained from meniscus (a tissue with mixed collagen types) to evaluate the potential of this method for identification of collagen type in a minimally-invasive clinical application. Concentration profiles of the tissue components obtained from multivariate analysis were in excellent agreement with histology and immunohistochemistry results. Bone and tendon showed a uniform distribution of predominantly type I collagen through the tissue. Normal cartilage showed a distribution of type II collagen and proteoglycan similar to the known composition, while in repair cartilage, the spectral distribution of both types I and II collagen were similar to that observed via immunohistochemistry. Using the probe, the outer and inner regions of the meniscus were shown to be primarily composed of type I and II collagen, respectively, in accordance with immunohistochemistry data. In summary, multivariate analysis of infrared spectra can indeed be used to differentiate collagen type I and type II, even in the presence of proteoglycan, in connective tissues

  20. Rapid Bacterial Identification Using Fourier Transform Infrared Spectroscopy

    SciTech Connect

    Valentine, Nancy B.; Johnson, Timothy J.; Su, Yin-Fong; Forrester, Joel B.

    2007-02-01

    Recent studies at Pacific Northwest National Laboratory (PNNL) using infrared spectroscopy combined with statistical analysis have shown the ability to identify and discriminate vegetative bacteria, bacterial spores and background interferents from one another. Since the anthrax releases in 2001, rapid identification of unknown powders has become a necessity. Bacterial endospores are formed by some Bacillus species as a result of the vegetative bacteria undergoing environmental stress, e.g. a lack of nutrients. Endospores are formed as a survival mechanism and are extremely resistant to heat, cold, sunlight and some chemicals. They become airborne easily and are thus readily dispersed which was demonstrated in the Hart building. Fourier Transform Infrared (FTIR) spectroscopy is one of several rapid analytical methods used for bacterial endospore identification. The most common means of bacterial identification is culturing, but this is a time-consuming process, taking hours to days. It is difficult to rapidly identify potentially harmful bacterial agents in a highly reproducible way. Various analytical methods, including FTIR, Raman, photoacoustic FTIR and Matrix Assisted Laser Desorption/Ionization (MALDI) have been used to identify vegetative bacteria and bacterial endospores. Each has shown certain areas of promise, but each has shortcomings in terms of sensitivity, measurement time or portability. IR spectroscopy has been successfully used to distinguish between the sporulated and vegetative state. [1,2] It has also shown its utility at distinguishing between the spores of different species. [2-4] There are several Bacillus species that occur commonly in nature, so it is important to be able to distinguish between the many different species versus those that present an imminent health threat. The spectra of the different sporulated species are all quite similar, though there are some subtle yet reproducible spectroscopic differences. Thus, a more robust and

  1. Fourier domain target transformation analysis in the thermal infrared

    NASA Technical Reports Server (NTRS)

    Anderson, D. L.

    1993-01-01

    Remote sensing uses of principal component analysis (PCA) of multispectral images include band selection and optimal color selection for display of information content. PCA has also been used for quantitative determination of mineral types and abundances given end member spectra. The preliminary results of the investigation of target transformation PCA (TTPCA) in the fourier domain to both identify end member spectra in an unknown spectrum, and to then calculate the relative concentrations of these selected end members are presented. Identification of endmember spectra in an unknown sample has previously been performed through bandmatching, expert systems, and binary classifiers. Both bandmatching and expert system techniques require the analyst to select bands or combinations of bands unique to each endmember. Thermal infrared mineral spectra have broad spectral features which vary subtly with composition. This makes identification of unique features difficult. Alternatively, whole spectra can be used in the classification process, in which case there is not need for an expert to identify unique spectra. Use of binary classifiers on whole spectra to identify endmember components has met with some success. These techniques can be used, along with a least squares fit approach on the endmembers identified, to derive compositional information. An alternative to the approach outlined above usese target transformation in conjunction with PCA to both identify and quantify the composition of unknown spectra. Preprocessing of the library and unknown spectra into the fourier domain, and using only a specific number of the components, allows for significant data volume reduction while maintaining a linear relationship in a Beer's Law sense. The approach taken here is to iteratively calculate concentrations, reducing the number of endmember components until only non-negative concentrations remain.

  2. Variable Temperature Infrared Spectroscopy Investigations of Benzoic Acid Desorption from Sodium and Calcium Montmorillonite Clays.

    PubMed

    Nickels, Tara M; Ingram, Audrey L; Maraoulaite, Dalia K; White, Robert L

    2015-12-01

    Processes involved in thermal desorption of benzoic acid from sodium and calcium montmorillonite clays are investigated by using variable temperature diffuse reflection Fourier transform infrared spectroscopy (DRIFTS). By monitoring the temperature dependence of infrared absorbance bands while heating samples, subtle changes in molecular vibrations are detected and employed to characterize specific benzoic acid adsorption sites. Abrupt changes in benzoic acid adsorption site properties occur for both clay samples at about 125 °C. Difference spectra absorbance band frequency variations indicate that adsorbed benzoic acid interacts with interlayer cations through water bridges and that these interactions can be disrupted by the presence of organic anions, in particular, benzoate. PMID:26647147

  3. Fourier Transform Microwave and Infrared Spectroscopic Investigation of Propiolactone

    NASA Astrophysics Data System (ADS)

    Chen, Ziqiu; van Wijngaarden, Jennifer

    2009-06-01

    The pure rotational spectrum of the four-membered ester ring propiolactone (C{_3}H{_4}O{_2}) has been measured in a supersonic jet between 7 and 22 GHz using Fourier transform microwave (FTMW) spectroscopy. For the normal isotopologue, a total of 19 a- and b-type transitions have been recorded. Fifteen transitions due to three different ^{13}C isotopologues have also been observed. The microwave spectrum was analyzed to obtain an improved set of ground state rotational constants in comparison to earlier microwave experiments. The new set of rotational parameters was used to predict the rovibrational band structure of the lowest frequency modes of propiolactone. A total of 12 vibrational band origins have been observed between 400 and 1500 cm^{-1} using the far infrared beamline of the Canadian Light Source coupled to a Bruker IFS125HR spectrometer. The spectra were recorded with a resolution of 0.000969 cm^{-1} and although the intensities of the bands vary, 9 bands are of sufficient quality for complete rovibrational assignment. The progress of the assignment of this rich spectrum will be discussed. D. W. Boone, C O. Britt and J. E. Boggs J. Chem. Phys. 43 (1190), 1965.

  4. Fourier transform infrared spectroscopy (FTIR) of laser-irradiated cementum

    NASA Astrophysics Data System (ADS)

    Rechmann, Peter; White, Joel M.; Cecchini, Silvia C. M.; Hennig, Thomas

    2003-06-01

    Utilizing Fourier Transform Infrared Spectroscopy (FTIR) in specular reflectance mode chemical changes of root cement surfaces due to laser radiation were investigated. A total of 18 samples of root cement were analyzed, six served as controls. In this study laser energies were set to those known for removal of calculus or for disinfection of periodontal pockets. Major changes in organic as well as inorganic components of the cementum were observed following Nd:YAG laser irradiation (wavelength 1064 nm, pulse duration 250 μs, free running, pulse repetition rate 20 Hz, fiber diameter 320 μm, contact mode; Iskra Twinlight, Fontona, Slovenia). Er:YAG laser irradiation (wavelength 2.94 μm, pulse duration 250 μs, free running, pulse repetition rate 6 Hz, focus diameter 620 μm, air water cooling 30 ml/min; Iskra Twinlight, Fontona, Slovenia) significantly reduced the Amid bands due to changes in the organic components. After irradiation with a frequency doubled Alexandrite laser (wavelength 377 nm, pulse duration 200 ns, q-switched, pulse repetition rate 20 Hz, beam diameter 800 μm, contact mode, water cooling 30 ml/min; laboratory prototype) only minimal reductions in the peak intensity of the Amide-II band were detected.

  5. Quantitative analysis of polyethylene blends by Fourier transform infrared spectroscopy.

    PubMed

    Cran, Marlene J; Bigger, Stephen W

    2003-08-01

    The quantitative analysis of binary polyethylene (PE) blends by Fourier transform infrared (FT-IR) spectroscopy has been achieved based on the ratio of two absorbance peaks in an FT-IR spectrum. The frequencies for the absorbance ratio are selected based on structural entities of the PE components in the blend. A linear relationship between the absorbance ratio and the blend composition was found to exist if one of the absorbance peaks is distinct to one of the components and the other peak is common to both components. It was also found that any peak resulting from short-chain branching in copolymers (such as linear low-density polyethylene (LLDPE) or metallocene-catalyzed LLDPE (mLLDPE)), is suitable for use as the peak that is designated as being distinct to that component. In order to optimize the linearity of the equation, however, the selection of the second common peak is the most important and depends on the blend system studied. Indeed, under certain circumstances peaks that are not spectrally distinct can be used successfully to apply the method. The method exhibits potential for the routine analysis of PE blends that have been calibrated prior to its application.

  6. Fourier Transform Infrared Spectroscopy and Photoacoustic Spectroscopy for Saliva Analysis.

    PubMed

    Mikkonen, Jopi J W; Raittila, Jussi; Rieppo, Lassi; Lappalainen, Reijo; Kullaa, Arja M; Myllymaa, Sami

    2016-09-01

    Saliva provides a valuable tool for assessing oral and systemic diseases, but concentrations of salivary components are very small, calling the need for precise analysis methods. In this work, Fourier transform infrared (FT-IR) spectroscopy using transmission and photoacoustic (PA) modes were compared for quantitative analysis of saliva. The performance of these techniques was compared with a calibration series. The linearity of spectrum output was verified by using albumin-thiocyanate (SCN(-)) solution at different SCN(-) concentrations. Saliva samples used as a comparison were obtained from healthy subjects. Saliva droplets of 15 µL were applied on the silicon sample substrate, 6 drops for each specimen, and dried at 37 ℃ overnight. The measurements were carried out using an FT-IR spectrometer in conjunction with an accessory unit for PA measurements. The findings with both transmission and PA modes mirror each other. The major bands presented were 1500-1750 cm(-1) for proteins and 1050-1200 cm(-1) for carbohydrates. In addition, the distinct spectral band at 2050 cm(-1) derives from SCN(-) anions, which is converted by salivary peroxidases to hypothiocyanate (OSCN(-)). The correlation between the spectroscopic data with SCN(-) concentration (r > 0.990 for transmission and r = 0.967 for PA mode) was found to be significant (P < 0.01), thus promising to be utilized in future applications.

  7. Fourier transform infrared studies in hypergolic ignition of ionic liquids.

    PubMed

    Chambreau, Steven D; Schneider, Stefan; Rosander, Michael; Hawkins, Tom; Gallegos, Christopher J; Pastewait, Matthew F; Vaghjiani, Ghanshyam L

    2008-08-28

    A class of room-temperature ionic liquids (RTILs) that exhibit hypergolic activity toward fuming nitric acid is reported. Fast ignition of dicyanamide ionic liquids when mixed with nitric acid is contrasted with the reactivity of the ionic liquid azides, which show high reactivity with nitric acid, but do not ignite. The reactivity of other potential salt fuels is assessed here. Rapid-scan, Fourier transform infrared (FTIR) spectroscopy of the preignition phase indicates the evolution of N 2O from both the dicyanamide and azide RTILs. Evidence for the evolution of CO 2 and isocyanic acid (HNCO) with similar temporal behavior to N 2O from reaction of the dicyanamide ionic liquids with nitric acid is presented. Evolution of HN 3 is detected from the azides. No evolution of HCN from the dicyanamide reactions was detected. From the FTIR observations, biuret reaction tests, and initial ab initio calculations, a mechanism is proposed for the formation of N 2O, CO 2, and HNCO from the dicyanamide reactions during preignition. PMID:18681416

  8. Ribosomal DNA nanoprobes studied by Fourier transform infrared spectroscopy.

    PubMed

    Fagundes, Jaciara; Castilho, Maiara L; Téllez Soto, Claudio A; Vieira, Laís de Souza; Canevari, Renata A; Fávero, Priscila P; Martin, Airton A; Raniero, Leandro

    2014-01-24

    Paracoccidioides brasiliensis (P. brasiliensis) is a thermo-dimorphic fungus that causes paracoccidioidomycosis. Brazil epidemiological data shows that endemic areas are the subtropical regions, especially where agricultural activities predominate such as the Southeast, South, and Midwest. There are several tests to diagnose paracoccidioidomycosis, but they have many limitations such as low sensitivity, high cost, and a cross-reacting problem. In this work, gold nanoprobes were used to identify P. brasiliensis as an alternative diagnostic technique, which is easier to apply, costs less, and has great potential for application. The specific Ribosomal sequence of P. brasiliensis DNA was amplified and used to design the nanoprobes using a thiol-modified oligonucleotide. The results of positive and negative tests were done by UV-visible and Fourier Transform Infrared (FT-IR) measurements. The deconvolution of FT-IR sample spectra showed differences in the vibrational modes from the hydrogen bridge NHN and NHO bands that form the double helix DNA for samples matching the DNA sequence of nanoprobes that could be used to classify the samples.

  9. Fourier transform infrared spectroscopy and near infrared spectroscopy for the quantification of defects in roasted coffees.

    PubMed

    Craig, Ana Paula; Franca, Adriana S; Oliveira, Leandro S; Irudayaraj, Joseph; Ileleji, Klein

    2015-03-01

    The coffee strip-picking harvesting method, preferred in Brazil, results in high percentages of immature and overripe beans, as the fruits in a single tree branch do not reach ripeness at the same time. This practice, together with inappropriate processing and storage conditions, contribute to the production of high amounts of defective coffee beans in Brazil, which upon roasting will impart negative sensory aspects to the beverage. Therefore, the development of analytical methodologies that will enable the discrimination and quantification of defective and non-defective coffees after roasting is rather desirable. Given that infrared spectroscopy has been successfully applied to coffee analysis, the objective of this work was to evaluate and to compare the performances of Fourier transform infrared (FTIR) and near infrared (NIR) spectroscopies for the quantification of defective beans in roasted coffees. Defective and non-defective Arabica coffee beans were manually selected, roasted, ground and sieved. Mixtures of defective and non-defective roasted and ground coffees were produced and analyzed, with % defects ranging from 0% to 30%. FTIR and NIR spectra were recorded, respectively, within a range of 3100-800 cm(-1) and 1200-2400 nm and submitted to mathematical processing. Quantitative models were developed by partial least squares regression (PLSR). Excellent predictive results were obtained indicating that defective coffees could be satisfactorily quantified. The correlation coefficients and the root mean squared errors of validation for the FTIR and NIR models developed to quantify the amount of defective roasted coffees mixed with non-defective ones were, respectively, as high as 0.891 and as low as 0.032, and as high as 0.953 and as low as 0.026. A comparison between the two techniques indicated that NIR provided more robust models. PMID:25618683

  10. Biomedical investigations using Fourier transform-infrared microspectroscopy.

    PubMed

    Bunaciu, Andrei A; Fleschin, Şerban; Aboul-Enein, Hassan Y

    2014-01-01

    One of the most exciting recent developments in infrared spectroscopy has been the coupling of the spectrometer to an infrared microscope. The combination of the new infrared spectrometer and a microscope was a natural thought of scientists in these fields. This development has been so rewarding and so useful in solving today's chemical problems that infrared microspectroscopy has quickly become a significant subclassification of infrared spectroscopy. Infrared microspectroscopy has a much longer history than the recent enthusiasm would imply, however. The great interest in the use of infrared spectroscopy to solve biomedical problems that occurred in recent years shortly spread into the medical and biological fields. The aim of this review is to discuss the new developments in applications of FT-IR microspectroscopy in biomedical analysis, covering the period between 2008 and 2013.

  11. Biomedical investigations using Fourier transform-infrared microspectroscopy.

    PubMed

    Bunaciu, Andrei A; Fleschin, Şerban; Aboul-Enein, Hassan Y

    2014-01-01

    One of the most exciting recent developments in infrared spectroscopy has been the coupling of the spectrometer to an infrared microscope. The combination of the new infrared spectrometer and a microscope was a natural thought of scientists in these fields. This development has been so rewarding and so useful in solving today's chemical problems that infrared microspectroscopy has quickly become a significant subclassification of infrared spectroscopy. Infrared microspectroscopy has a much longer history than the recent enthusiasm would imply, however. The great interest in the use of infrared spectroscopy to solve biomedical problems that occurred in recent years shortly spread into the medical and biological fields. The aim of this review is to discuss the new developments in applications of FT-IR microspectroscopy in biomedical analysis, covering the period between 2008 and 2013. PMID:25391565

  12. Air quality monitoring based on Fourier transform infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Zheng, Wei; Wang, Yan; Wang, Rui

    2006-09-01

    The use of optical techniques to identify and quantify atmospheric pollutants has been focused within the past two decades. Fourier Transform Infrared (FTIR) spectroscopy has proven to be a powerful tool for multi-component analysis of air quality monitoring. The technique has been used for gaseous samples by extractive sampling as well as in the open-path configuration. The present contribution has described the application of FTIR to analyze gaseous pollutants in ambient air in detail. The study for the detection limits of the interested gas, the design of the multipass White mirror system, and the experimental results are described. The White cell is employed to increase the absorbance relative to noise in the absorbance spectrum by increasing the path length without proportional loss of signal. A classical least squares (CLS) fit is used to match the scaled standards or previously measured absorption profiles to those of the observed spectrum in the specified spectral analysis regions for simultaneous quantification of the compounds of interest, plus several other ambient air constituents. The regions were chosen carefully to provide optimum detection of the compounds of interest with minimum interference by other compounds. Specially, spectrum subtraction and differential absorption concepts are introduced into FTIR data analysis. The optimal window for CO, S0 II, NO II, NO and CO II would be the region at 2250-2020 cm -1, 1230-1070 cm -1, 2940-2840 cm -1, 1965-1775 cm -1, and around 668.24 cm -1 respectively. Deviations from traditional measured results for all approaches are in 10%.

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

    ERIC Educational Resources Information Center

    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)

  14. Midwave infrared imaging Fourier transform spectrometry of combustion plumes

    NASA Astrophysics Data System (ADS)

    Bradley, Kenneth C.

    A midwave infrared (MWIR) imaging Fourier transform spectrometer (IFTS) was used to successfully capture and analyze hyperspectral imagery of combustion plumes. Jet engine exhaust data from a small turbojet engine burning diesel fuel at a low rate of 300 cm3/min was collected at 1 cm -1 resolution from a side-plume vantage point on a 200x64 pixel window at a range of 11.2 meters. Spectral features of H2O, CO, and CO2 were present, and showed spatial variability within the plume structure. An array of thermocouple probes was positioned within the plume to aid in temperature analysis. A single-temperature plume model was implemented to obtain spatially-varying temperatures and plume concentrations. Model-fitted temperatures of 811 +/- 1.5 K and 543 +/- 1.6 K were obtained from plume regions in close proximity to thermocouple probes measuring temperatures of 719 K and 522 K, respectively. Industrial smokestack plume data from a coal-burning stack collected at 0.25 cm-1 resolution at a range of 600 meters featured strong emission from NO, CO, CO2, SO 2, and HCl in the spectral region 1800-3000 cm-1. A simplified radiative transfer model was employed to derive temperature and concentrations for clustered regions of the 128x64 pixel scene, with corresponding statistical error bounds. The hottest region (closest to stack centerline) was 401 +/- 0.36 K, compared to an in-stack measurement of 406 K, and model-derived concentration values of NO, CO2, and SO2 were 140 +/- 1 ppmV, 110,400 +/- 950 ppmV, and 382 +/- 4 ppmV compared to in-stack measurements of 120 ppmV (NOx), 94,000 ppmV, and 382 ppmV, respectively. In-stack measurements of CO and HCl were not provided by the stack operator, but model-derived values of 19 +/- 0.2 ppmV and 111 +/- 1 ppmV are reported near stack centerline. A deployment to Dugway Proving Grounds, UT to collect hyperspectral imagery of chemical and biological threat agent simulants resulted in weak spectral signatures from several species. Plume

  15. Polymer standards for testing Fourier transform infrared spectrometers

    NASA Astrophysics Data System (ADS)

    Bowie, Bryan T.; Griffiths, Peter R.

    1998-06-01

    An ideal sample for monitoring the photometric accuracy of Fourier transform infrared (FT-IR) spectrometers should be a self-supporting solid that is stable over a period of several years. Ideally, the spectrum of this sample should also have no interference fringes and the bands of interest should be stable over a wide temperature range. Two differently processed isotactic polypropylene samples, one stress-relieved and the other extruded, mounted between two BaF2˙ windows were investigated for this purpose. The 841-cm-1 band of polypropylene has been investigated as a possible wavenumber and photometric standard, because it is sharp, is not overlapped by neighboring bands and absorbs in an atmospheric window. When measured at 2 cm-1 resolution, the band centers (as calculated by their center of mass) are 841.68 cm-1 and 840.08 cm-1 for the stress-relieved and extruded polymer respectively. When the sample temperature changes from 10 °C to 50 °C, the band shifts by 0.03 cm-1 and 0.014 cm-1 for the stress-relieved and extruded polymer respectively. The full width at half height (FWHH) of the band increases by 0.33 cm-1 for both films when the temperature is increased from 10 °C to 50 °C. Conversely, the absorbance decreases by 0.085 and 0.058 for the stress-relieved and extruded film respectively when the temperature is increased from 10 °C to 50 °C. The percent deviation of the band area is 4.69 and 2.96 for the stress-relieved and extruded polymer respectively. Another possible issue to be concerned with when using a polymer as a standard is the effect of dichroism. The intensity of the 841-cm-1 band of the stress relieved polymer varies by 4.5% when the orientation of incident polarized radiation is varied by 90° about an axis normal to the plane of the polymer sample. When two layers of the polymer are overlaid such that the backbone chains of each layer are oriented orthogonally, the intensity of the analogous band for the extruded polymer changes by

  16. Predicting cotton stelometer fiber strength by fourier transform infrared spectroscopy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The strength of cotton fibers is one of several important end-use characteristics. In routine programs, it has been mostly assessed by automation-oriented high volume instrument (HVI) system. An alternative method for cotton strength is near infrared (NIR) spectroscopy. Although previous NIR models ...

  17. Reflective Fourier ptychography.

    PubMed

    Pacheco, Shaun; Zheng, Guoan; Liang, Rongguang

    2016-02-01

    The Fourier ptychography technique in reflection mode has great potential applications in tissue imaging and optical inspection, but the current configuration either has a limitation on cut-off frequency or is not practical. By placing the imaging aperture stop outside the illumination path, the illumination numerical aperture (NA) can be greater than the imaging NA of the objective lens. Thus, the cut-off frequency achieved in the proposed optical system is greater than twice the objective's NA divided by the wavelength (2NAobj/λ ), which is the diffraction limit for the cut-off frequency in an incoherent epi-illumination configuration. We experimentally demonstrated that the synthesized NA is increased by a factor of 4.5 using the proposed optical concept. The key advantage of the proposed system is that it can achieve high-resolution imaging over a large field of view with a simple objective. It will have a great potential for applications in endoscopy, biomedical imaging, surface metrology, and industrial inspection. PMID:26891601

  18. Raman and infrared techniques for fighting drug-related crime: a preliminary assessment

    NASA Astrophysics Data System (ADS)

    Valussi, Silvia; Underhill, Mark

    2006-09-01

    A proof-of-concept hand-held Raman spectrometer and a commercial portable system based on Attenuated Total Reflectance Fourier Transform Infrared spectroscopy (ATR-FTIR) were assessed for the rapid, "at scene" analysis of illicit drugs. The objectives of such an assessment were twofold: 1) to determine the suitability of the systems in practical forensic casework and 2) to determine the potential of the use of such systems in covert operations. Data obtained are promising and demonstrate the potential advantages and limitations of the use of these techniques in these fields of operation.

  19. EVALUATION OF A PORTABLE FOURIER TRANSFORM INFRARED GAS ANALYZER FOR MEASUREMENTS OF AIR TOXICS IN POLLUTION PREVENTION RESEARCH

    EPA Science Inventory

    A portable Fourier transform infrared gas analyzer with a photoacoustic detector performed reliably during pollution prevention research at two industrial facilities. It exhibited good agreement (within approximately 6%) with other analytical instruments (dispersive infrared and ...

  20. Discrimination of different red wine by Fourier-transform infrared and two-dimensional infrared correlation spectroscopy

    NASA Astrophysics Data System (ADS)

    Zhang, Yan-ling; Chen, Jian-bo; Lei, Yu; Zhou, Qun; Sun, Su-qin; Noda, Isao

    2010-06-01

    Fourier-transform infrared spectroscopy (FT-IR) and two-dimensional infrared (2D IR) correlation spectroscopy were applied to analyze main components of liquid red wine with different sugar contents and volatilization residues of dry red wine from different manufactures. The infrared spectra, second derivative spectra of dry red wine show the typical peaks of alcohol, while the spectra of sweet wine are composed of the peaks of both alcohol and sugar, and the contribution of sugar enhanced as the increase of sugar content. Using principal component analysis (PCA) method, dry and sweet wine can be readily classified. Analysis of the infrared spectra of the volatilization residues of dry red wine samples from five different manufactures indicates that dry red wine may be composed of glycerol, carboxylic acids or esters and carboxyl ate, at the same time, different dry red wine show different characteristic peaks in the second derivative spectra and 2D IR correlation spectra, which can be used to discriminate the different manufactures and evaluate the quality of wine samples. The results suggested that infrared spectroscopy is a direct and effective method for the analysis of principle components of different red wines and discrimination of different red wines.

  1. Maskelynite formation via solid-state transformation: Evidence of infrared and x-ray anisotropy

    DOE PAGESBeta

    Jaret, Steven J.; Ehm, Lars; Woerner, William R.; Phillips, Brian L.; Nekvasil, Hanna; Wright, Shawn P.; Glotch, Timothy D.

    2015-03-24

    We present optical microscopy, micro-Raman spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, high-energy X-ray total scattering experiments, and micro-Fourier transform infrared (micro-FTIR) spectroscopy on shocked labradorite from the Lonar Crater, India. We show that maskelynite of shock class 2 is structurally more similar to fused glass than to crystalline plagioclase. However, there are slight but significant differences – preservation of original pre-impact igneous zoning, anisotropy at Infrared wavelengths, X-ray anisotropy, and preservation of some intermediate range order – which are all consistent with a solid-state transformation formation of maskelynite.

  2. Voigt line infrared atmospheric transmittance calculations by Fourier transform

    NASA Astrophysics Data System (ADS)

    Neuendorffer, A. C.

    1980-04-01

    The absorption coefficient space of an IR atmospheric path contains the linear superposition of many Voigt spectral lines. This paper discusses the practical application of Karp's method to the simulation of satellite transmittance and radiance observations by using fast Fourier transforms on the recursively generated Voigt transforms. Although the procedure is physically straightforward, it is nonetheless computationally demanding and suited primarily to narrow isolated Q-branch regions. Performing the calculation on a 2.4/cm wide 15-micron CO2 Q-branch region demonstrates that 4% of the total absorption takes place above 0.1 mb. This absorption is in the cold mesopause and results in a 1-2% radiation deficit with its inclusion in a satellite radiation calculation.

  3. Application of Fourier transform infrared spectroscopy to silica diagenesis: The opal-A to opal-CT transformation

    SciTech Connect

    Rice, S.B.; Freund, H.; Huang, W.L.; Clouse, J.A.; Isaacs, C.M.

    1995-10-02

    An important goal in silica diagenesis research is to understand the kinetics of opal transformation from noncrystalline opal-A to the disordered silica polymorph opal-CT. Because the conventional technique for monitoring the transformation, powder X-ray diffraction (XRD), is applicable only to phases with long-range order, the authors used Fourier transform infrared spectroscopy (FTIR) to monitor the transformation. They applied this technique, combined with XRD and TEM, to experimental run products and natural opals from the Monterey Formation and from siliceous deposits in the western Pacific Ocean. Using a ratio of two infrared absorption intensities ({omega} = I{sub 472 cm{sup {minus}1}}/I{sub 500 cm{sup {minus}1}}), the relative proportions of opal-A and opal-CT can be determined. The progress of the transformation is marked by changes in slope of {omega} vs. depth or time when a sufficient stratigraphic profile is available. There are three stages in the opal-A to opal-CT reaction: (1) opal-A dissolution; (2) opal-CT precipitation, whose end point is marked by completion of opal-A dissolution; and (3) opal-CT ordering, during which tridymite stacking is eliminated in favor of crystobalite stacking.

  4. Photoacoustic Fourier Transform Infrared (FTIR) Spectroscopy Of Solids

    NASA Astrophysics Data System (ADS)

    Vidrine, D. Warren

    1981-10-01

    After discovering the photoacoustic effect, Alexander Graham Bell predicted its use in spectrometers, and that it would find its greatest utility "in the ultra-red." More than ninety years were required to fulfil his first prediction, and the second is still a prophecy. There is no record whether he ever imagined that an invention being developed that same winter by a young protege of his named Albert Michelson would ever be combined with his photoacoustic effect. A century later, the combination was made by Farrow Burnham, and Eyring, using a visible-range interferometer spectrometer of their own design. Soon afterwards, Rockley and myself, working independently, applied the technique to infrared measurements of solid samples. Photoacoustic cells are now commercially available as FT-IR accessories, and the technique is in use in the field.

  5. An improved fusion algorithm for infrared and visible images based on multi-scale transform

    NASA Astrophysics Data System (ADS)

    Li, He; Liu, Lei; Huang, Wei; Yue, Chao

    2016-01-01

    In this paper, an improved fusion algorithm for infrared and visible images based on multi-scale transform is proposed. First of all, Morphology-Hat transform is used for an infrared image and a visible image separately. Then two images were decomposed into high-frequency and low-frequency images by contourlet transform (CT). The fusion strategy of high-frequency images is based on mean gradient and the fusion strategy of low-frequency images is based on Principal Component Analysis (PCA). Finally, the final fused image is obtained by using the inverse contourlet transform (ICT). The experiments and results demonstrate that the proposed method can significantly improve image fusion performance, accomplish notable target information and high contrast and preserve rich details information at the same time.

  6. Infrared small target enhancement via phase spectrum of Quaternion Fourier Transform

    NASA Astrophysics Data System (ADS)

    Qi, Shengxiang; Ma, Jie; Li, Hang; Zhang, Shuiping; Tian, Jinwen

    2014-01-01

    Small target enhancement is one of the crucial stages in infrared small target detection. In this paper, we propose a new method using phase spectrum of Quaternion Fourier Transform to enhance small targets while suppressing backgrounds for infrared images. This is inspired by the property that regularly Gaussian-like shape small targets could be considered as attractively salient signal in infrared images and the location information of such signal is implicitly contained in the phase spectrum from frequency domain. Formally, in the proposed method, we adopt the phase spectrum of Quaternion Fourier Transform instead of using traditional Fourier Transform to enhance the targets since the quaternion provides at most four data channels than only one for the latter, which could be helpful to broad types of background clutters by adding more information. For the construction of the quaternion, we present a second-order directional derivative filter via facet model to compute four second order directional derivative maps from four directions respectively as the four data channels. This filter is used to suppress noises and distinguish the targets and backgrounds into separably different textures so that it would boost the robustness of small target enhancement. In experiments, some typical infrared images with various scenes are tested to validate the effectiveness of the proposed method. The results demonstrate that our method actually has good performance and outperforms several state-of-the-art methods, which can be further used for infrared small target detection and tracking.

  7. High Speed Countercurrent Chromatography/Fourier Transform Infrared (HSCCC/FT-IR) Spectrometry

    NASA Astrophysics Data System (ADS)

    Romanach, Rodolfo J.; de Haseth, James A.

    1985-12-01

    High Speed Countercurrent Chromatography/Fourier transform infrared (HSCCC/FT-IR) spectrometry is present-ed. High solute-to-solvent ratios can be obtained in separations performed using HSCCC. At these high solute concentrations it is possible to obtain spectra of solutes without solvent elimination, even in the presence of polar solvents, such as water and methanol.

  8. Postdispersion system for astronomical observations with Fourier transform spectrometers in the thermal infrared

    NASA Technical Reports Server (NTRS)

    Wiedermann, Guenter; Jennings, D. E.; Hanel, R. H.; Kunde, V. G.; Moseley, S. H.

    1989-01-01

    A postdispersion system for astronomical observations with Fourier transform spectrometers in the thermal infrared has been developed which improves the sensitivity of radiation noise limited observations by reducing the spectral range incident on the detector. Special attention is given to the first-generation blocked impurity band detector. Planetary, solar, and stellar observations are reported.

  9. Topics in Chemical Instrumentation: Fourier Transform-Infrared Spectroscopy: Part I. Instrumentation.

    ERIC Educational Resources Information Center

    Perkins, W. D.

    1986-01-01

    Discusses: (1) the design of the Fourier Transform-Infrared Spectroscopy (FT-IR) spectrometer; (2) the computation of the spectrum from the interferogram; and (3) the use of apodization. (Part II will discuss advantages of FT-IR over dispersive techniques and show applications of FT-IR to difficult spectroscopic measurements.) (JN)

  10. Limitations and potential of spectral subtractions in fourier-transform infrared (FTIR) spectroscopy of soil samples

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil science research is increasingly applying Fourier transform infrared (FTIR) spectroscopy for analysis of soil organic matter (SOM). However, the compositional complexity of soils and the dominance of the mineral component can limit spectroscopic resolution of SOM and other minor components. The...

  11. PARTICULATE MATTER MEASUREMENTS USING OPEN-PATH FOURIER TRANSFORM INFRARED SPECTROSCOPY

    EPA Science Inventory

    Open-path Fourier transform infrared (OP-FT1R) spectroscopy is an accepted technology for measuring gaseous air contaminants. OP-FT1R absorbance spectra acquired during changing aerosols conditions reveal related changes in very broad baseline features. Usually, this shearing of ...

  12. Transfer of Calibration for barley quality from dispersive intrument to fourier transform near-infrared instrument

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study deals with transferring the near-infrared (NIR) calibration models for quality assessment of barley between two instruments with different resolutions and number of data points, a Fourier transform instrument (master) and a dispersive instrument (slave). A file of spectra from 206 ground ...

  13. Chemometric Analysis of Multicomponent Biodegradable Plastics by Fourier Transform Infrared Spectrometry: The R-Matrix Method

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A new chemometric method based on absorbance ratios from Fourier transform infrared spectra was devised to analyze multicomponent biodegradable plastics. The method uses the BeerLambert law to directly compute individual component concentrations and weight losses before and after biodegradation of c...

  14. Imaging Fourier Transform Spectro-polarimetry in the Infrared

    NASA Astrophysics Data System (ADS)

    Jurgenson, C. A.; Stencel, R. E.; Stout, J.

    2004-12-01

    Imaging spectro-polarimetry has the capability to trace polarization changes in dust grains throughout an extended region of interest. An instrument that has the capability to achieve moderately high resolution (R = 2000 at 10 microns) via a stepping Fourier transform spectrometer, while preserving imaging polarimetry capabilities (TNTCAM2, Jurgenson et al. 2003), is set to achieve first light during early 2005. Motion control of the interferometer, as well as array control/readout is accomplished via an FPGA card programmed in LabVIEW(c). Mid-IR polarization studies are useful in approximating grain shapes and sizes in dusty environments. Correlation studies between mid and near-IR features can be used to test the core-mantle arrangement of grain growth. Polarization analysis is currently only possible between 8-13 microns, but the interferometer, as well as TNTCAM2, can operate at selected bandpasses in the near-IR region. A wire grid and waveplate would need to be purchased for work in the near-IR. Laboratory calibration results, both spectral and polarization, are reported. We are seeking collaborators in shared-risk science with this instrument, so please contact the authors if interested. Sigma Xi Grants In Aid of Research as well as the estate of William Herschel Womble provided funding for this endeavor.

  15. Broadband Mid-Infrared Comb-Resolved Fourier Transform Spectroscopy

    NASA Astrophysics Data System (ADS)

    Lee, Kevin; Mills, Andrew; Mohr, Christian; Jiang, Jie; Fermann, Martin; Maslowski, Piotr

    2014-06-01

    We report on a comb-resolved, broadband, direct-comb spectroscopy system in the mid-IR and its application to the detection of trace gases and molecular line shape analysis. By coupling an optical parametric oscillator (OPO), a 100 m multipass cell, and a high-resolution Fourier transform spectrometer (FTS), sensitive, comb-resolved broadband spectroscopy of dilute gases is possible. The OPO has radiation output at 3.1-3.7 and 4.5-5.5 μm. The laser repetition rate is scanned to arbitrary values with 1 Hz accuracy around 417 MHz. The comb-resolved spectrum is produced with an absolute frequency axis depending only on the RF reference (in this case a GPS disciplined oscillator), stable to 1 part in 10^9. The minimum detectable absorption is 1.6x10-6 wn Hz-1/2. The operating range of the experimental setup enables access to strong fundamental transitions of numerous molecular species for applications based on trace gas detection such as environmental monitoring, industrial gas calibration or medical application of human breath analysis. In addition to these capabilities, we show the application for careful line shape analysis of argon-broadened CO band spectra around 4.7 μm. Fits of the obtained spectra clearly illustrate the discrepancy between the measured spectra and the Voigt profile (VP), indicating the need to include effects such as Dicke narrowing and the speed-dependence of the collisional width and shift in the line shape model, as was shown in previous cw-laser studies. In contrast to cw-laser based experiments, in this case the entire spectrum (˜ 250 wn) covering the whole P and R branches can be measured in 16 s with 417 MHz resolution, decreasing the acquisition time by orders of magnitude. The parallel acquisition allows collection of multiple lines simultaneously, removing the correlation of possible temperature and pressure drifts. While cw-systems are capable of measuring spectra with higher precision, this demonstration opens the door for fast

  16. Pentachlorodibenzo-p-dioxin isomer differentiation by capillary gas chromatography fourier transform infrared spectroscopy

    SciTech Connect

    Grainger, J.; Reddy, V.V.; Patterson, D.G. Jr. )

    1988-09-01

    Analysis of polychlorinated dibenzo-p-dioxin (PCDD) isomers has been the focus of a number of recent investigations due to the extreme toxicities of specific laterally tetrachlorinated isomers. These investigations have primarily been directed toward 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD), the most toxic PCDD isomer and toward isomer differentiation of TCDD isomers as a group. With the exception of pentachlorodibenzo-p-dioxin (PnCDD) isomer specific determinations based on calculated retention indices, isomer differentiation of the 14 PnCDD isomers has not been reported although 1,2,3,7,8-PnCDD is nearly as toxic as 2,3,7,8-TCDD. Chromatographically independent methods for PCDD isomer assignment have been reported by x-ray powder diffraction, proton nuclear magnetic resonance ({sup 1}H NMR), gas chromatography/matrix isolation Fourier transform infrared (MI/FTIR) spectroscopy, diffuse reflectance infrared Fourier transformation (DRIFT) spectroscopy and gas chromatography/Fourier transform infrared (GC/FTIR) spectroscopy. Although TCDD isomer assignments by the various methods are substantially in agreement, some differences are yet to be resolved. Vapor-phase reference infrared spectra are presented for the 14 PnCDD isomers. These spectra were recorded from low (< 10) microgram quantities for each isomer. The spectrum of each isomer is unique, allowing for positive isomer identification and individual group frequency absorption characteristics as a function of isomer structure.

  17. Infrared and multi-type images fusion algorithm based on contrast pyramid transform

    NASA Astrophysics Data System (ADS)

    Xu, Hua; Wang, Yan; Wu, Yujing; Qian, Yunsheng

    2016-09-01

    A fusion algorithm for infrared and multi-type images based on contrast pyramid transform (CPT) combined with Otsu method and morphology is proposed in this paper. Firstly, two sharpened images are combined to the first fused image based on information entropy weighted scheme. Afterwards, two enhanced images and the first fused one are decomposed into a series of images with different dimensions and spatial frequencies. To the low-frequency layer, the Otsu method is applied to calculate the optimal segmentation threshold of the first fused image, which is subsequently used to determine the pixel values in top layer fused image. With respect to the high-frequency layers, the top-bottom hats morphological transform is employed to each layer before maximum selection criterion. Finally, the series of decomposed images are reconstructed and then superposed with the enhanced image processed by morphological gradient operation as a second fusion to get the final fusion image. Infrared and visible images fusion, infrared and low-light-level (LLL) images fusion, infrared intensity and infrared polarization images fusion, and multi-focus images fusion are discussed in this paper. Both experimental results and objective metrics demonstrate the effectiveness and superiority of the proposed algorithm over the conventional ones used to compare.

  18. Tensor Fukunaga-Koontz transform for small target detection in infrared images

    NASA Astrophysics Data System (ADS)

    Liu, Ruiming; Wang, Jingzhuo; Yang, Huizhen; Gong, Chenglong; Zhou, Yuanshen; Liu, Lipeng; Zhang, Zhen; Shen, Shuli

    2016-09-01

    Infrared small targets detection plays a crucial role in warning and tracking systems. Some novel methods based on pattern recognition technology catch much attention from researchers. However, those classic methods must reshape images into vectors with the high dimensionality. Moreover, vectorizing breaks the natural structure and correlations in the image data. Image representation based on tensor treats images as matrices and can hold the natural structure and correlation information. So tensor algorithms have better classification performance than vector algorithms. Fukunaga-Koontz transform is one of classification algorithms and it is a vector version method with the disadvantage of all vector algorithms. In this paper, we first extended the Fukunaga-Koontz transform into its tensor version, tensor Fukunaga-Koontz transform. Then we designed a method based on tensor Fukunaga-Koontz transform for detecting targets and used it to detect small targets in infrared images. The experimental results, comparison through signal-to-clutter, signal-to-clutter gain and background suppression factor, have validated the advantage of the target detection based on the tensor Fukunaga-Koontz transform over that based on the Fukunaga-Koontz transform.

  19. Study on Senna alata and its different extracts by Fourier transform infrared spectroscopy and two-dimensional correlation infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Adiana, M. A.; Mazura, M. P.

    2011-04-01

    Senna alata L. commonly known as candle bush belongs to the family of Fabaceae and the plant has been reported to possess anti-inflammatory, analgesic, laxative and antiplatelet-aggregating activity. In order to develop a rapid and effective analysis method for studying integrally the main constituents in the medicinal materials and their extracts, discriminating the extracts from different extraction process, comparing the categories of chemical constituents in the different extracts and monitoring the qualities of medicinal materials, we applied Fourier transform infrared spectroscopy (FT-IR) associated with second derivative infrared spectroscopy and two-dimensional infrared correlation spectroscopy (2D-IR) to study the main constituents of S. alata and its different extracts (extracted by hexane, dichloromethane, ethyl acetate and methanol in turn). The findings indicated that FT-IR and 2D-IR can provide many holistic variation rules of chemical constituents. Use of the macroscopical fingerprint characters of FT-IR and 2D-IR spectrum can identify the main chemical constituents in medicinal materials and their extracts, but also compare the components differences among similar samples. In a conclusion, FT-IR spectroscopy combined with 2D correlation analysis provides a powerful method for the quality control of traditional medicines.

  20. Infrared refractive index dispersion of polymethyl methacrylate spheres from Mie ripples in Fourier-transform infrared microscopy extinction spectra.

    PubMed

    Blümel, R; Bağcioğlu, M; Lukacs, R; Kohler, A

    2016-09-01

    We performed high-resolution Fourier-transform infrared (FTIR) spectroscopy of a polymethyl methacrylate (PMMA) sphere of unknown size in the Mie scattering region. Apart from a slow, oscillatory structure (wiggles), which is due to an interference effect, the measured FTIR extinction spectrum exhibits a ripple structure, which is due to electromagnetic resonances. We fully characterize the underlying electromagnetic mode structure of the spectrum by assigning mode numbers to each of the ripples in the measured spectrum. We show that analyzing the ripple structure in the spectrum in the wavenumber region from about 3000  cm-1 to 8000  cm-1 allows us to determine both the unknown radius of the sphere and the PMMA index of refraction, which shows a strong frequency dependence in this infrared spectral region. While in this paper we focus on examining a PMMA sphere as an example, our method of determining the refractive index and its dispersion from infrared extinction spectra is generally applicable for the determination of the index of refraction of any transparent substance that can be shaped into micron-sized spheres. PMID:27607489

  1. High-pressure-low-temperature cryostat designed for use with fourier transform infrared spectrometers and time-resolved infrared spectroscopy.

    PubMed

    Calladine, James A; Love, Ashley; Fields, Peter A; Wilson, Richard G M; George, Michael W

    2014-01-01

    The design for a new high-pressure-low-temperature infrared (IR) cell for performing experiments using conventional Fourier transform infrared or fast laser-based time-resolved infrared spectroscopy, in a range of solvents, is described. The design builds upon a commercially available compressor and cold end (Polycold PCC(®) and CryoTiger(®)), which enables almost vibration-free operation, ideal for use with sensitive instrumentation. The design of our cell and cryostat allows for the study of systems at temperatures from 77 to 310 K and at pressures up to 250 bar. The CaF2 windows pass light from the mid-IR to the ultraviolet (UV), enabling a number of experiments to be performed, such as Raman, UV-visible absorption spectroscopy, and time-resolved techniques where sample excitation/probing using continuous wave or pulsed lasers is required. We demonstrate the capabilities of this cell by detailing two different applications: (i) the reactivity of a range of Group V-VII organometallic alkane complexes using time-resolved spectroscopy on the millisecond timescale and (ii) the gas-to-liquid phase transition of CO2 at low temperature, which is applicable to measurements associated with transportation issues related to carbon capture and storage.

  2. Infrared refractive index dispersion of polymethyl methacrylate spheres from Mie ripples in Fourier-transform infrared microscopy extinction spectra.

    PubMed

    Blümel, R; Bağcioğlu, M; Lukacs, R; Kohler, A

    2016-09-01

    We performed high-resolution Fourier-transform infrared (FTIR) spectroscopy of a polymethyl methacrylate (PMMA) sphere of unknown size in the Mie scattering region. Apart from a slow, oscillatory structure (wiggles), which is due to an interference effect, the measured FTIR extinction spectrum exhibits a ripple structure, which is due to electromagnetic resonances. We fully characterize the underlying electromagnetic mode structure of the spectrum by assigning mode numbers to each of the ripples in the measured spectrum. We show that analyzing the ripple structure in the spectrum in the wavenumber region from about 3000  cm-1 to 8000  cm-1 allows us to determine both the unknown radius of the sphere and the PMMA index of refraction, which shows a strong frequency dependence in this infrared spectral region. While in this paper we focus on examining a PMMA sphere as an example, our method of determining the refractive index and its dispersion from infrared extinction spectra is generally applicable for the determination of the index of refraction of any transparent substance that can be shaped into micron-sized spheres.

  3. Research on algorithm for infrared hyperspectral imaging Fourier transform spectrometer technology

    NASA Astrophysics Data System (ADS)

    Wan, Lifang; Chen, Yan; Liao, Ningfang; Lv, Hang; He, Shufang; Li, Yasheng

    2015-08-01

    This paper reported the algorithm for Infrared Hyperspectral Imaging Radiometric Spectrometer Technology. Six different apodization functions are been used and compared, and the phase corrected technologies of Forman is researched and improved, fast fourier transform(FFT)is been used in this paper instead of the linear convolution to reduce the quantity of computation.The interferograms is achieved by the Infrared Hyperspectral Imaging Radiometric Spectrometer which are corrected and rebuilded by the improved algorithm, this algorithm reduce the noise and accelerate the computing speed with the higher accuracy of spectrometers.

  4. Detection and measurement of electroreflectance on quantum cascade laser device using Fourier transform infrared microscope

    SciTech Connect

    Enobio, Eli Christopher I.; Ohtani, Keita; Ohno, Yuzo; Ohno, Hideo

    2013-12-02

    We demonstrate the use of a Fourier Transform Infrared microscope system to detect and measure electroreflectance (ER) from mid-infrared quantum cascade laser (QCL) device. To characterize intersubband transition (ISBT) energies in a functioning QCL device, a microscope is used to focus the probe on the QCL cleaved mirror. The measured ER spectra exhibit resonance features associated to ISBTs under applied electric field in agreement with the numerical calculations and comparable to observed photocurrent, and emission peaks. The method demonstrates the potential as a characterization tool for QCL devices.

  5. Study on the Identification of Radix Bupleuri from Its Unofficial Varieties Based on Discrete Wavelet Transformation Feature Extraction of ATR-FTIR Spectroscopy Combined with Probability Neural Network

    PubMed Central

    Jin, Wenying; Wan, Chayan; Cheng, Cungui

    2015-01-01

    The attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR) was employed to acquire the infrared spectra of Radix Bupleuri and its unofficial varieties: the root of Bupleurum smithii Wolff and the root of Bupleurum bicaule Helm. The infrared spectra and spectra of Fourier self-deconvolution (FSD), discrete wavelet transform (DWT), and probability neural network (PNN) of these species were analyzed. By the method of FSD, there were conspicuous differences of the infrared absorption peak intensity of different types between Radix Bupleuri and its unofficial varieties. But it is hard to tell the differences between the root of Bupleurum smithii Wolff and the root of Bupleurum bicaule. The differences could be shown more clearly when the DWT was used. The research result shows that by the DWT technology it is easier to identify Radix Bupleuri from its unofficial varieties the root of Bupleurum smithii Wolff and the root of Bupleurum bicaule. PMID:25784938

  6. Evaluation of different grades of ginseng using Fourier-transform infrared and two-dimensional infrared correlation spectroscopy

    NASA Astrophysics Data System (ADS)

    Zhang, Yan-ling; Chen, Jian-bo; Lei, Yu; Zhou, Qun; Sun, Su-qin; Noda, Isao

    2010-06-01

    Ginseng is one of the most widely used herbal medicines which have many kinds of pharmaceutical values. The discrimination of grades of ginseng includes the cultivation types and the growth years herein. To evaluate the different grades of ginseng, the fibrous roots and rhizome roots of ginseng were analyzed by Fourier-transform infrared and two-dimensional infrared correlation spectroscopy in this paper. The fibrous root and rhizome root of ginseng have different content of starch, calcium oxalate and other components. For the fibrous roots of ginseng, mountain cultivation ginseng (MCG), garden cultivation ginseng (GCG) and transplanted cultivation ginseng (TCG) have clear difference in the infrared spectra and second derivative spectra in the range of 1800-400 cm -1, and clearer difference was observed in the range of 1045-1160 and 1410-1730 cm -1 in 2D synchronous correlation spectra. Three kinds of ginseng can be clustered very well by using SIMCA analysis on the basis of PCA as well. For the rhizome roots, the content of calcium oxalate and starch change with growth years in the IR spectra, and some useful procedure can be obtained by the analysis of 2D IR synchronous spectra in the range of 1050-1415 cm -1. Also, ginsengs cultivated in different growth years were clustered perfectly by using SIMCA analysis. The results suggested that different grades of ginseng can be well recognized using the mid-infrared spectroscopy assisted by 2D IR correlation spectroscopy, which provide the macro-fingerprint characteristics of ginseng in different parts and supplied a rapid, effective approach for the evaluation of the quality of ginseng.

  7. Fourier Transform Infrared Spectroscopic Studies Of Wheat In The Mid Infrared

    NASA Astrophysics Data System (ADS)

    Olinger, Jill M.; Griffiths, Peter R.

    1989-12-01

    Official grain standards of the United States state that wheat may be divided into seven classes which are: Durum, Red Durum, Hard Red Spring, Hard Red Winter, Soft Red Winter, White, and Mixed.1 Most end uses of wheat involve converting the grain into flour through one of a variety of grinding methods. The quality of wheat-based products is often very dependent upon the type or class of wheat which was used to make the flour. Pasta products, for example, are made almost exclusively from the flour of durum wheats, which are the hardest of the wheats listed above. The highest quality breads are produced using flour from wheats classed as hard, whereas cakes, cookies and pastries are considered best when flour from wheats classed as soft are used. It is obvious then that the capability of determining the class of a particular wheat, especially with respect to hardness, is of economic importance to growers, processors, and merchants of wheat and wheat products. Hardness has been measured in many different ways 2-5 but, as of yet, no one method has become the method of choice. This paper reports on the use of principal components analysis (PCA) of mid infrared diffuse reflectance (DR) spectra of diluted ground wheats to aid in the classification of those wheats with respect to their hardness. The theory and mathematics involved in a principal component analysis have been described elsewhere.9

  8. Fourier transform infrared study of a phase transition in solid chlorodifluoromethane

    NASA Astrophysics Data System (ADS)

    Anderson, A.; Beardsall, A. J.; Fraser, Jim

    1994-01-01

    Infrared spectra of solid chlorodifluoromethane (CHClF2 or Freon 22) at temperatures between 12 K and 105 K have been recorded. Both lattice and internal mode regions have been investigated by utilizing two Fourier transform spectrometers, one for the far-infrared region (20 - 400 cm-1) and the other for the mid-infrared region (400 - 4000 cm-1). Evidence for a solid state phase transition at 55 +/- 5 K is presented. Multiplet structure for the nine internal modes is observed over a wide range of temperature and in most cases is shown to result from crystal field rather than isotopic or other effects. This indicates that both phases are ordered with rather large unit cells, and that the phase transition is therefore of a displacive type.

  9. Use of in situ Fourier transform infrared spectroscopy to study freezing and drying of cells.

    PubMed

    Wolkers, Willem F; Oldenhof, Harriëtte

    2015-01-01

    An infrared spectrum gives information about characteristic molecular vibrations of specific groups in molecules. Fourier transform infrared spectroscopy can be applied to study lipids and proteins in cells or tissues. Spectra can be collected during cooling, heating, or dehydration of a sample using a temperature-controlled sample holder or a sample holder for controlled dehydration. In the current chapter, acquisition and analysis of infrared spectra during cooling, warming, or dehydration is described. Spectra analysis involving assessment of specific band positions, areas, or ratios is described. Special emphasis is given on studying membrane phase behavior and protein denaturation in cells or tissues. In addition, methods are presented to determine the water-to-ice phase change during freezing, dehydration kinetics, and the glass transition temperature of amorphous systems.

  10. Terahertz time-domain and Fourier-transform infrared spectroscopy of traditional Korean pigments

    NASA Astrophysics Data System (ADS)

    Hong, Taeyoon; Choi, Kyujin; Ha, Taewoo; Park, Byung Cheol; Sim, Kyung Ik; Kim, Jong Hyeon; Kim, Jae Hoon; Kwon, Jy Eun; Lee, Sanghyun; Kang, Dai Ill; Lee, Han Hyoung

    2014-03-01

    Representative traditional Korean pigments (oyster shell white [hobun], massicot [miltaseung], indigo [jjok], azurite [seokcheong], malachite [seokrok], and red lead [yeondan]) have been studied with terahertz time-domain spectroscopy (THz-TDS) and Fourier-transform infrared spectroscopy (FTIRS) over the spectral region of 0.1-7.5 THz. Both the refractive index n and the extinction coefficient k were simultaneously and independently determined in the terahertz region without a Kramers-Kronig analysis while the absoprtion coefficient spectra were acquired in the infrared region. All pigments studied in the present work exhibited a set of characteristic absorption peaks unique to the pigment species in addition to a background that increased with increasing frequency. Our study demonstrates that terahertz and infrared techniques can be useful identification and diagnostic tools for the traditional Korean pigments used in heritage buildings and artworks.

  11. Lime kiln source characterization: Lime manufacturing industry Fourier transform infrared spectroscopy. Final report

    SciTech Connect

    Toney, M.L.

    1999-07-01

    The purpose of this testing program is to obtain uncontrolled and controlled hydrogen chloride (HCl) and speciated hydrocarbon Hazardous Air Pollutants (HAPs) emissions data from lime production plants to support a national emission standard for hazardous air pollutants (NESHAP). This report presents data from the Fourier Transform Infrared Spectroscopy (FTIR) measurements. FTIR source testing was conducted for the following purposes: Quantify HCl emission levels; and Gather screening (i.e., qualitative) data on other HAP emissions.

  12. The Characterisation of Pluripotent and Multipotent Stem Cells Using Fourier Transform Infrared Microspectroscopy

    PubMed Central

    Cao, Julie; Ng, Elizabeth S.; McNaughton, Donald; Stanley, Edouard G.; Elefanty, Andrew G.; Tobin, Mark J.; Heraud, Philip

    2013-01-01

    Fourier transform infrared (FTIR) microspectroscopy shows potential as a benign, objective and rapid tool to screen pluripotent and multipotent stem cells for clinical use. It offers a new experimental approach that provides a holistic measurement of macromolecular composition such that a signature representing the internal cellular phenotype is obtained. The use of this technique therefore contributes information that is complementary to that acquired by conventional genetic and immunohistochemical methods. PMID:24065090

  13. Metabolic fingerprinting of lichen Usnea baileyi by Fourier transform infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Bakar, Siti Zaharah Abu; Latip, Jalifah; bin Din, Laily; Samsuddin, Mohd Wahid

    2014-09-01

    The lichen Usnea baileyi collected from different environments was characterised using Fourier transform infrared spectroscopy. This preliminary study was done to determine the effects of different environment populations on U. baileyi chemical composition. Results showed that the absorbance peaks of Golf Course 2 (GCU2) are more intense compared to Taman Awana (TA), Jalan Awana (JA) and Jalan Gohtong (JG). U. baileyi contains of dibenzofurans, depsides, depsidones, xanthones and terpenoids.

  14. Fourier transform infrared spectroscopic study of intact cells of the nitrogen-fixing bacterium Azospirillum brasilense

    NASA Astrophysics Data System (ADS)

    Kamnev, A. A.; Ristić, M.; Antonyuk, L. P.; Chernyshev, A. V.; Ignatov, V. V.

    1997-06-01

    The data of Fourier transform infrared (FTIR) spectroscopic measurements performed on intact cells of the soil nitrogen-fixing bacterium Azospirillum brasilense grown in a standard medium and under the conditions of an increased metal uptake are compared and discussed. The structural FTIR information obtained is considered together with atomic absorption spectrometry (AAS) data on the content of metal cations in the bacterial cells. Some methodological aspects concerning preparation of bacterial cell samples for FTIR measurements are also discussed.

  15. Source brightness fluctuation correction of solar absorption fourier transform mid infrared spectra

    NASA Astrophysics Data System (ADS)

    Ridder, T.; Warneke, T.; Notholt, J.

    2011-06-01

    The precision and accuracy of trace gas observations using solar absorption Fourier Transform infrared spectrometry depend on the stability of the light source. Fluctuations in the source brightness, however, cannot always be avoided. Current correction schemes, which calculate a corrected interferogram as the ratio of the raw DC interferogram and a smoothed DC interferogram, are applicable only to near infrared measurements. Spectra in the mid infrared spectral region below 2000 cm-1 are generally considered uncorrectable, if they are measured with a MCT detector. Such measurements introduce an unknown offset to MCT interferograms, which prevents the established source brightness fluctuation correction. This problem can be overcome by a determination of the offset using the modulation efficiency of the instrument. With known modulation efficiency the offset can be calculated, and the source brightness correction can be performed on the basis of offset-corrected interferograms. We present a source brightness fluctuation correction method which performs the smoothing of the raw DC interferogram in the interferogram domain by an application of a running mean instead of high-pass filtering the corresponding spectrum after Fourier transformation of the raw DC interferogram. This smoothing can be performed with the onboard software of commercial instruments. The improvement of MCT spectra and subsequent ozone profile and total column retrievals is demonstrated. Application to InSb interferograms in the near infrared spectral region proves the equivalence with the established correction scheme.

  16. Identification of geographical origin of Lignosus samples using Fourier transform infrared and two-dimensional infrared correlation spectroscopy

    NASA Astrophysics Data System (ADS)

    Choong, Yew-Keong; Xu, Chang-Hua; Lan, Jin; Chen, Xiang-Dong; Jamal, Jamia Azdina

    2014-07-01

    Lignosus spp. is a medicinal mushroom that has been used as a folk remedy for ‘clearing heat’, eliminating phlegm, ‘moistening the lungs’ and as an anti-breast cancer agent. The objective of this study was to identify the active chemical constituents of the mushroom limited number of sample by using Fourier transform infrared (FTIR) and two-dimensional correlation Fourier transform infrared spectroscopy (2DIR). The sample M26/08 was purchased from a Chinese medicine shop in Kuala Lumpur, while M49/07 and M23/08 were collected from Semenyih and Kuala Lipis respectively. The three samples have strong absorption peaks corresponding to the stretching vibration of conjugated carbonyl Cdbnd O group. Both fresh sample M49/07 and M23/08 showed an identical peak of 1655 cm-1, whereby M26/08 contained stretching vibration of 1648 cm-1. The peaks from 1260 cm-1 onwards were assignation of carbohydrate content including saccharides. Spectrum of M26/08 showed region from 1260 cm-1 to 950 cm-1 which was 99.4% similar to M23/08. The chemical constitutes of M26/08 and M23/08 were closely correlated (r = 0.97), whereas the correlation coefficient of M26/08 and M49/07 was 0.94. The use of second derivative and 2DIR spectroscopy enhanced the distinct differences to a more significant level. Although the geographical origin of M26/08 was unknown, its origin was determined by comparing with M49/07 and M23/08. The visual and colorful 2DIR spectra provided dynamic structural information of the chemical components analyzed and demonstrated a powerful and useful approach using the spectroscopy of different samples.

  17. Chemometric evaluation of near infrared, fourier transform infrared, and Raman spectroscopic models for the prediction of nimodipine polymorphs.

    PubMed

    Siddiqui, Akhtar; Rahman, Ziyaur; Sayeed, Vilayat A; Khan, Mansoor A

    2013-11-01

    The objective of this study was to assess the performance of the chemometric model to predict the proportion of the recrystallized polymorphs of nimodipine from the cosolvent formulations. Ranging from 100% to 0% (w/w) of polymorph I, the two polymorphs mixtures were prepared and characterized spectroscopically using Fourier transformed infrared spectroscopy (FTIR), near-infrared spectroscopy (NIR), and Raman spectroscopy. Instrumental responses were treated to construct multivariate calibration model using principal component regression (PCR) and partial least square regression approaches. Treated data showed better model fitting than without treatment, which demonstrated higher correlation coefficient (R(2) ) and lower root mean square of standard error (RMSE) and standard error (SE). Multiple scattering correction and standard normal variate exhibited higher R(2) and lower RMSE and SE values than second derivative. Goodness of fit for FTIR and NIR (R(2) ∼ 0.99) data was better than Raman (R(2) ∼ 0.95). Furthermore, the models were applied on the recrystallized polymorphs obtained by storing nimodipine-cosolvent formulations at selected stability conditions. The relative composition of the polymorphs differed with storage conditions. NIR-chemical imaging on recrystallized sample of nimodipine at 15°C qualitatively corroborated the model-based prediction of the two polymorphs. Therefore, these studies strongly suggest the importance of the potential utility of the chemometric model in predicting nimodipine polymorphs.

  18. Infrared and visible image fusion based on region growing and contourlet transform

    NASA Astrophysics Data System (ADS)

    Zhao, Bingjie; Gao, Wei; Song, Zongxi

    2013-09-01

    According to the characteristics of infrared and visible images, a new image fusion method based on region growing and contourlet transform is proposed in this paper. To obtain more complementary information, the method is designed as a two-stage procedure. Firstly, the input infrared image is processed with region growing to segment the thermal target. Different fusion rules are adopted in target and background regions, respectively. For the target region, local energy is utilized as the fusion rule of the first fusion to fuse the thermal target and the visible image, while for the non-target region, we reserve the visible background information. Secondly, in order to fully add original information of the source images and avoid loss of information caused by segmentation, we make the second fusion between the visible image and the result image of the one-stage fusion. For good properties of localization, directionality and anisotropy, we adopt contourlet transform as the second fusion method. Experiments are carried out and the results show that our method is clearer in visual quality and effective in quantitative evaluations and the fused images are better than those resulting of using wavelet transform and contourlet transform.

  19. Measurement of nitrogen content in a gas mixture by transforming the nitrogen into a substance detectable with nondispersive infrared detection

    DOEpatents

    Owen, Thomas E.; Miller, Michael A.

    2007-03-13

    A method of determining the amount of nitrogen in a gas mixture. The constituent gases of the mixture are dissociated and transformed to create a substance that may measured using nondispersive infrared adsorption techniques.

  20. Measurement of nitrogen content in a gas mixture by transforming the nitrogen into a substance detectable with nondispersive infrared detection

    DOEpatents

    Owen, Thomas E.; Miller, Michael A.

    2010-08-24

    A method of determining the amount of nitrogen in a gas mixture. The constituent gases of the mixture are dissociated and transformed to create a substance that may measured using nondispersive infrared adsorption techniques.

  1. Identification and characterization of salmonella serotypes using DNA spectral characteristics by fourier transform infrared (FT-IR) spectroscopy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Analysis of DNA samples of Salmonella serotypes (Salmonella Typhimurium, Salmonella Enteritidis, Salmonella Infantis, Salmonella Heidelberg and Salmonella Kentucky) were performed using Fourier transform infrared spectroscopy (FT-IR) spectrometer by placing directly in contact with a diamond attenua...

  2. Quantitative determination of the fat, protein, lactose, and water content in cow milk using Fourier transform infrared spectrometry

    NASA Astrophysics Data System (ADS)

    Luinge, Hendrik J.; Hop, E.; Lutz, E. T.; van der Maas, John H.; Holstra, A.; van Hemert, H. A.; Koops, J.; Wooldrik, H.; de Jong, E. A.; Ellen, G.

    1992-03-01

    In this paper the quantitative analysis of the four major components in cow milk using Fourier transform infrared spectrometry is described. Least squares regression using selected wavenumber regions is compared with full spectrum methods such as principal component regression (PCR) and partial least squares regression (PLS). Results are comparable with data obtained from infrared filter instruments with respect to precision and accuracy.

  3. Characterising cytotoxic agent action as a function of the cell cycle using Fourier transform infrared microspectroscopy.

    PubMed

    Jimenez-Hernandez, M; Brown, M D; Hughes, C; Clarke, N W; Gardner, P

    2015-07-01

    Fourier Transform Infrared (FTIR) micro-spectroscopy measurements were acquired to study infrared signatures of chemotherapeutic response as a function of the cell cycle. Renal carcinoma Caki-2 cells were exposed to IC50 doses of 5-fluorouracil and Paclitaxel for a period of 24 hours. The inherent cell cycle infrared signatures from untreated and drug-treated cells were successfully retrieved by the construction of a robust SVM able to discriminate the cell cycle phases of this cell line with an average accuracy of 83.7%. The overriding infrared signature observed relates to an apoptotic biochemical response that does not appear to be correlated with the events affected by the drugs' mode of action or the cell cycle. Since apoptosis is a well conserved mechanism among living species, these results suggest that both the stages of proliferation as well as the absence/presence of apoptosis need to be taken into account in order to elucidate the fine biochemical details revealing the immediate cellular response to the drug in order to assign reliable spectral patterns of drug action. PMID:26030288

  4. Macromolecular concentrations in bovine nasal cartilage by Fourier transform infrared imaging and principal component regression.

    PubMed

    Yin, Jianhua; Xia, Yang

    2010-11-01

    Fourier transform infrared imaging (FT-IRI) and principal component regression (PCR) were used to quantitatively determine collagen and proteoglycan concentrations in bovine nasal cartilage (BNC). An infrared spectral library was first established by obtaining eleven infrared spectra from a series of collagen and chondroitin 6-sulfate mixed in different ratios. FT-IR images were obtained from 6-μm-thick sections of BNC specimens at 6.25-μm pixel size. The spectra from the FT-IR images were imported into a PCR program to obtain the relative concentrations of collagen and proteoglycan in BNC, based on the spectral library of pure chemicals. These PCR-determined concentrations agreed with the molecular concentrations determined biochemically using an enzyme digestion assay. Use of the imaging approach revealed that proteoglycan loss in the specimens occurs first at the surface of the tissue block when compared with the middle portion of the tissue block. The quantitative correlation of collagen and proteoglycan revealed that their infrared absorption peak areas at 1338 and 1072-855 cm(-1) can only be used as qualitative indicators of the molecular contents. The use of PCR with FT-IRI offers an accurate tool to spatially determine the distributions of macromolecular concentration in cartilage.

  5. Fourier transform infrared absorption spectroscopy characterization of gaseous atmospheric pressure plasmas with 2 mm spatial resolution

    SciTech Connect

    Laroche, G.; Vallade, J.; Bazinette, R.; Hernandez, E.; Hernandez, G.; Massines, F.; Nijnatten, P. van

    2012-10-15

    This paper describes an optical setup built to record Fourier transform infrared (FTIR) absorption spectra in an atmospheric pressure plasma with a spatial resolution of 2 mm. The overall system consisted of three basic parts: (1) optical components located within the FTIR sample compartment, making it possible to define the size of the infrared beam (2 mm Multiplication-Sign 2 mm over a path length of 50 mm) imaged at the site of the plasma by (2) an optical interface positioned between the spectrometer and the plasma reactor. Once through the plasma region, (3) a retro-reflector module, located behind the plasma reactor, redirected the infrared beam coincident to the incident path up to a 45 Degree-Sign beamsplitter to reflect the beam toward a narrow-band mercury-cadmium-telluride detector. The antireflective plasma-coating experiments performed with ammonia and silane demonstrated that it was possible to quantify 42 and 2 ppm of these species in argon, respectively. In the case of ammonia, this was approximately three times less than this gas concentration typically used in plasma coating experiments while the silane limit of quantification was 35 times lower. Moreover, 70% of the incoming infrared radiation was focused within a 2 mm width at the site of the plasma, in reasonable agreement with the expected spatial resolution. The possibility of reaching this spatial resolution thus enabled us to measure the gaseous precursor consumption as a function of their residence time in the plasma.

  6. Comprehensive Infrared Study of Tetryl, Dinitrotoluene, and Trinitrotoluene Compounds.

    PubMed

    Puiu, Adriana; Giubileo, Gianfranco; Cesaro, Stella Nunziante; Bencivenni, Luigi

    2015-12-01

    The present work describes an experimental and theoretical study of energetic materials used for detecting explosives in order to prevent terrorist actions, as well as for de-mining projects. Particular attention was devoted to examining the infrared absorption spectroscopy of classic explosives in order to create a useful mobile apparatus for on-field detection of explosives. This paper reports the vibrational absorption spectra of tetryl, dinitrotoluene, and trinitrotoluene molecules approached using two different spectroscopic techniques, Fourier transform infrared spectroscopy (FT-IR) and laser photoacoustic spectroscopy (LPAS). Diffuse reflectance Fourier transform infrared spectra of all samples were analyzed in a very wide spectral range (400-7500 cm(-1)) showing for the first time the existence of weak absorption bands attributable to overtones or combination bands, while laser photoacoustic spectroscopy spectra have been investigated in the fingerprint region of organic compounds that share the CO2 laser emission range (~920-1100 cm(-1)). The Fourier transform infrared spectra of both matrix isolated dinitrotoluenes have been also investigated. The theoretical treatment of tetryl is reported for the first time.

  7. Differentiation of neotropical fish species with statistical analysis of fourier transform infrared photoacoustic spectroscopy data.

    PubMed

    Almeida, Francylaine S; Lima, Sandro M; Andrade, Luis H C; Súarez, Yzel R

    2012-07-01

    Fourier transform infrared photoacoustic spectroscopy (FTIR-PAS) was applied to nineteen fish species in Brazil's Upper Paraná River basin to identify differences in the structural composition of their scales. To differentiate the species, a canonical discriminant analysis was used to indicate the most important absorption peaks in the mid-infrared region. Significant differences were found in the chemical composition of scales among the studied fish species, with Wilk's lambda = 5.2 × 10(-6), F((13,18,394)) = 37.57, and P < 0.001, indicating that O-CH(2) wag at 1396 cm(-1) can be used as a biomarker of this species group. The species could be categorized into four groups according to phylogenetic similarity, suggesting that the O-CH(2) 1396 cm(-1) absorbance is related to the biological traits of each species. This procedure can also be used to complement evolutionary studies.

  8. Diamond cell Fourier transform infrared spectroscopy transmittance analysis of black toners on questioned documents.

    PubMed

    Assis, A C Almeida; Barbosa, M F; Nabais, J M Valente; Custódio, A F; Tropecelo, P

    2012-01-10

    This paper describes the use of a diamond cell Fourier transform infrared (FTIR) spectroscopy methodology for the analysis of black toners commercialised in Portugal. A total of one hundred and thirty-eight samples from eighteen manufacturers were analysed in transmittance mode through a diamond cell. This methodology was considered to be non-destructive as it allows the forensic analysis of the questioned documents while preserving their integrity. The questioned documents' substrate (paper sheets) has no influence on the final result. This technique shows high repeatability and intermediate precision. Spectra were organized in twenty distinct groups based on their main chemical characteristics and relative peak intensity; and a black toner infrared spectral library was developed. Spectral matches between forty-five blind samples and the database resulted in a 100% positive identification to the correct group. PMID:21831548

  9. Fourier transform infrared spectroscopy techniques for the analysis of drugs of abuse

    NASA Astrophysics Data System (ADS)

    Kalasinsky, Kathryn S.; Levine, Barry K.; Smith, Michael L.; Magluilo, Joseph J.; Schaefer, Teresa

    1994-01-01

    Cryogenic deposition techniques for Gas Chromatography/Fourier Transform Infrared (GC/FT-IR) can be successfully employed in urinalysis for drugs of abuse with detection limits comparable to those of the established Gas Chromatography/Mass Spectrometry (GC/MS) technique. The additional confidence of the data that infrared analysis can offer has been helpful in identifying ambiguous results, particularly, in the case of amphetamines where drugs of abuse can be confused with over-the-counter medications or naturally occurring amines. Hair analysis has been important in drug testing when adulteration of urine samples has been a question. Functional group mapping can further assist the analysis and track drug use versus time.

  10. High-definition Fourier transform infrared spectroscopic imaging of breast tissue

    NASA Astrophysics Data System (ADS)

    Leslie, L. Suzanne; Kadjacsy-Balla, Andre; Bhargava, Rohit

    2015-03-01

    Breast cancer diagnosis relies on staining serial sections of a biopsy in a process that can be time intensive and costly. Fourier transform infrared imaging (FT-IR) is a non-destructive, label-free chemical imaging technique that uses the vibrational structure of the biological molecules of the sample to provide contrast for images at any absorption peak in the mid-infrared. The full potential of spectroscopic imaging has been limited by the spatial resolution provided by most commercial instruments. By increasing the magnification and numerical aperture of the microscope, image pixel sizes on the order of 1.1 micron can be achieved, allowing HD FT-IR spectroscopic imaging to provide high quality images that could aid in histopathology, diagnosis, and studies of breast cancer progression.

  11. Preliminary study on diffuse axonal injury by Fourier transform infrared spectroscopy histopathology imaging.

    PubMed

    Yang, Tiantong; He, Guanglong; Zhang, Xiang; Chang, Lin; Zhang, Haidong; Ripple, Mary G; Fowler, David R; Li, Ling

    2014-01-01

    The objective of this study was to evaluate the application of Fourier transform infrared (FTIR) spectroscopy for detecting diffuse axonal injury (DAI) in a mouse model. Brain tissues from DAI mouse model were prepared with H&E, silver, and β-amyloid precursor protein (β-APP) immunohistochemistry stains and were also studied with FTIR. The infrared spectrum images showed high absorption of amide II in the subcortical white matter of the experimental mouse brain, while there was no obvious expression of amide II in the control mouse brain. The areas with high absorption of amide II were in the same distribution as the DAI region confirmed by the silver and β-APP studies. The result suggests that high absorption of amide II correlates with axonal injury. The use of FTIR imaging allows the biochemical changes associated with DAI pathologies to be detected in the tissues, thus providing an important adjunct method to the current conventional pathological diagnostic techniques.

  12. Infrared

    NASA Astrophysics Data System (ADS)

    Vollmer, M.

    2013-11-01

    underlying physics. There are now at least six different disciplines that deal with infrared radiation in one form or another, and in one or several different spectral portions of the whole IR range. These are spectroscopy, astronomy, thermal imaging, detector and source development and metrology, as well the field of optical data transmission. Scientists working in these fields range from chemists and astronomers through to physicists and even photographers. This issue presents examples from some of these fields. All the papers—though some of them deal with fundamental or applied research—include interesting elements that make them directly applicable to university-level teaching at the graduate or postgraduate level. Source (e.g. quantum cascade lasers) and detector development (e.g. multispectral sensors), as well as metrology issues and optical data transmission, are omitted since they belong to fundamental research journals. Using a more-or-less arbitrary order according to wavelength range, the issue starts with a paper on the physics of near-infrared photography using consumer product cameras in the spectral range from 800 nm to 1.1 µm [1]. It is followed by a series of three papers dealing with IR imaging in spectral ranges from 3 to 14 µm [2-4]. One of them deals with laboratory courses that may help to characterize the IR camera response [2], the second discusses potential applications for nondestructive testing techniques [3] and the third gives an example of how IR thermal imaging may be used to understand cloud cover of the Earth [4], which is the prerequisite for successful climate modelling. The next two papers cover the vast field of IR spectroscopy [5, 6]. The first of these deals with Fourier transform infrared spectroscopy in the spectral range from 2.5 to 25 µm, studying e.g. ro-vibrational excitations in gases or optical phonon interactions within solids [5]. The second deals mostly with the spectroscopy of liquids such as biofuels and special

  13. Structural study of photodegraded acrylic-coated lime wood using Fourier transform infrared and two-dimensional infrared correlation spectroscopy.

    PubMed

    Popescu, Carmen-Mihaela; Simionescu, Bogdan C

    2013-06-01

    The weathering of acrylic films and acrylic-coated lime wood (Tillia cordata Mill.) were examined using Fourier transform infrared (FT-IR) and two-dimensional infrared correlation spectroscopy. The obtained results showed chemical changes induced by exposure to weathering conditions, in both films and coated wood. The observed spectral changes of the acrylic films refer to the absorption band assigned to the C-O stretching, which progressively decreases with increasing exposure time. In the spectra of treated wood samples the main signal indicating the advance of oxidation during the photodegradation exposure is the gradual increase and broadening of the band in the carbonyl region. This is due to the formation of the non-hydrogen bonded aliphatic carboxylic acids and γ-lactone structures in the acrylic resin and of the nonconjugated ketones, carboxyl groups, and lactones in wood. As a consequence, the increase of the 1734 cm(-1) band is due to the degradation of lignin from wood surface. These observations are also supported by the decreased intensities of the bands at 1598 and 1505 cm(-1), assigned to C=C of aromatic skeletal (lignin). The relative intensity of the characteristic aromatic lignin band at 1505 cm(-1) decreases up to 25% of its original value after weathering, being less than half of the value obtained for uncoated wood. Two-dimensional infrared (2D IR) correlation spectroscopy was used to identify the sequence of the modifications of the different stretching vibrations bands under the weathering conditions, the method allowing the prediction of the order of degradation reactions. The acrylic resin degradation starts with the formation of radicals by abstraction of the tertiary hydrogen atoms of the methyl acrylate units and the α-CH3 groups from the ethyl methacrylate units. The subsequent decomposition and oxidation led to the formation of alcohol groups, hydroperoxides, ketones, and/or carboxylic acid groups. The 2D IR correlation spectra of

  14. Imaging open-path Fourier transform infrared spectrometer for 3D cloud profiling

    NASA Astrophysics Data System (ADS)

    Rentz Dupuis, Julia; Mansur, David J.; Vaillancourt, Robert; Carlson, David; Evans, Thomas; Schundler, Elizabeth; Todd, Lori; Mottus, Kathleen

    2009-05-01

    OPTRA is developing an imaging open-path Fourier transform infrared (I-OP-FTIR) spectrometer for 3D profiling of chemical and biological agent simulant plumes released into test ranges and chambers. An array of I-OP-FTIR instruments positioned around the perimeter of the test site, in concert with advanced spectroscopic algorithms, enables real time tomographic reconstruction of the plume. The approach is intended as a referee measurement for test ranges and chambers. This Small Business Technology Transfer (STTR) effort combines the instrumentation and spectroscopic capabilities of OPTRA, Inc. with the computed tomographic expertise of the University of North Carolina, Chapel Hill.

  15. Characterization of biotechnologically and medically relevant yeasts (fungi) by Fourier transform infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Serfas, Ottmar; Naumann, Dieter; Standfuss, Gabriele; Brueggemann, Lutz; Flemming, Ingeborg

    1992-03-01

    The Fourier-transform infrared spectra of intact procaryotic cells (bacteria) have already been used in the past to characterize (differentiate, classify and identify) a variety of bacterial strains and taxa. In this paper the essential features of a methodology are described which extend the FT-IR pattern recognition approach to intact eucaryotic cells (yeasts/fungi). Basically, the characteristic information pertaining to microbial FT-IR patterns is explored by applying multivariate statistics and cluster analysis to both the time and frequency domain of the mid-ir spectral data.

  16. HIGH-RESOLUTION FOURIER TRANSFORM SPECTROSCOPY OF Nb i IN THE NEAR-INFRARED

    SciTech Connect

    Er, A.; Güzelçimen, F.; Başar, Gö.; Öztürk, I. K.; Tamanis, M.; Ferber, R.; Kröger, S. E-mail: sophie.kroeger@htw-berlin.de

    2015-11-15

    In this study, a Fourier Transform spectrum of Niobium (Nb) is investigated in the near-infrared spectral range from 6000 to 12,000 cm{sup −1} (830–1660 nm). The Nb spectrum is produced using a hollow cathode discharge lamp in an argon atmosphere. Both Nb and Ar spectral lines are visible in the spectrum. A total of 110 spectral lines are assigned to the element Nb. Of these lines, 90 could be classified as transitions between known levels of atomic Nb. From these classified Nb i transitions, 27 have not been listed in literature previously. Additionally, 8 lines are classified for the first time.

  17. Fourier Transform Infrared Spectroscopic Analysis Of Plastic Capsule Materials Exposed To Deuterium-Tritium (DT) Gas

    SciTech Connect

    Schoonover, J R; Steckle, Jr., W P; Elliot, N; Ebey, P S; Nobile, A; Nikroo, A; Cook, R C; Letts, S A

    2005-06-16

    Planar samples of varying thicknesses of both CH and CD glow discharge polymer have been measured with Fourier transform infrared (FTIR) spectroscopy before and after exposure to deuterium-tritium (DT) gas at elevated temperature and pressure. Planar samples of polyimide films made from both hydrogenated and deuterated precursors have also been examined by FTIR before and after DT exposure. The post-exposure FTIR spectra demonstrated no measurable exchange of hydrogen with deuterium or tritium for either polymer. Evidence for oxidation of the glow discharge polymer due to atmospheric oxygen was the only chemical change indicated by the FTIR data.

  18. Planetary infrared astronomy using a cryogenic postdisperser on Fourier transform spectrometers

    NASA Technical Reports Server (NTRS)

    Jennings, D. E.; Kunde, V. G.; Hanel, R. A.; Maguire, W. C.; Lamb, G. M.

    1986-01-01

    High resolution infrared spectra of planets from ground-based observatories were analyzed and instrumentation to improve sensitivity was developed. A cryogenic postdisperser (a narrow bandpass spectral filter) for use with Fourier transform spectrometers (FTS's) at facility observatories was constructed. This instrument has improved the sensitivity of FTS observations at 8 to 20 microns by about an order of magnitude. Spectra of Jupiter, Saturn and Comet Halley were obtained using the postdisperser with FTS facilities at the Kitt Peak 4-meter and McMath telescopes. Spectral resolution as high as 0.01/cm was achieved.

  19. Design of spatio-temporally modulated static infrared imaging Fourier transform spectrometer.

    PubMed

    Wang, WenCong; Liang, JingQiu; Liang, ZhongZhu; Lü, JinGuang; Qin, YuXin; Tian, Chao; Wang, WeiBiao

    2014-08-15

    A novel static medium wave infrared (MWIR) imaging Fourier transform spectrometer (IFTS) is conceptually proposed and experimentally demonstrated. In this system, the moving mirror in traditional temporally modulated IFTS is replaced by multi-step micro-mirrors to realize the static design. Compared with the traditional spatially modulated IFTS, they have no slit system and are superior with larger luminous flux and higher energy efficiency. The use of the multi-step micro-mirrors can also make the system compact and light.

  20. Design and fabrication of step mirrors used in space-modulated Fourier transform infrared spectrometer.

    PubMed

    Zheng, Ying; Liang, Jingqiu; Liang, Zhongzhu

    2013-01-14

    A model of miniaturized space-modulated Fourier transform infrared spectrometer (FTIR) is given. The two step mirrors as the key components are designed and a lithography-electroplating technique used to fabricate the small step mirror is proposed. We analyze the effect of the experiment results resulted from fabricating technics on the recovery spectrum in theory, and demonstrate that the lithography-electroplating technique is an effective method to fabricate the step mirror, which make miniaturized FTIR realized. We believe that the performances of FTIR can be better realized by optimizing experimental conditions to make this fabricating method more attractive.

  1. Source brightness fluctuation correction of solar absorption Fourier Transform mid infrared spectra

    NASA Astrophysics Data System (ADS)

    Ridder, T.; Warneke, T.; Notholt, J.

    2011-01-01

    Solar absorption Fourier Transform infrared spectrometry is considered a precise and accurate method for the observation of trace gases in the atmosphere. The precision and accuracy of such measurements are dependent on the stability of the light source. Fluctuations in the source brightness reduce the precision and accuracy of the trace gas concentrations, but cannot always be avoided. Thus, a strong effort is made within the community to reduce the impact of source brightness fluctuations by applying a correction on the spectra following the measurements. So far, it could be shown that the precision and accuracy of CO2 total column concentrations could be improved by applying a source brightness fluctuation correction to spectra in the near infrared spectral region. The analysis of trace gas concentrations obtained from spectra in the mid infrared spectral region is fundamental. However, spectra below 2000 cm-1 are generally considered uncorrectable, if they are measured with a MCT detector. Such measurements introduce an unknown offset to MCT interferograms, which prevents a source brightness fluctuation correction. Here, we show a method of source brightness fluctuation correction, which can be applied on spectra in the whole infrared spectral region including spectra measured with a MCT detector. We present a solution to remove the unknown offset in MCT interferograms allowing MCT spectra for an application of source brightness fluctuation correction. This gives an improvement in the quality of MCT spectra and we demonstrate an improvement in the retrieval of O3 profiles and total column concentrations. For a comparison with previous studies, we apply our source brightness fluctuation correction method on spectra in the near infrared spectral region and show an improvement in the retrieval of CO2 total column concentrations.

  2. Aqueous infrared carboxylate absorbances: Aliphatic di-acids

    USGS Publications Warehouse

    Cabaniss, S.E.; Leenheer, J.A.; McVey, I.F.

    1998-01-01

    Aqueous attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectra of 18 aliphatic di-carboxylic acids are reported as a function of pH. The spectra show isosbestic points and intensity changes which indicate that Beer's law is obeyed, and peak frequencies lie within previously reported ranges for aqueous carboxylates and pure carboxylic acids. Intensity sharing from the symmetric carboxylate stretch is evident in many cases, so that bands which are nominally due to alkyl groups show increased intensity at higher pH. The asymmetric stretch of the HA- species is linearly related to the microscopic acidity constant of the H2A species, with ??pK 2 intervening atoms). The results suggest that aqueous ATR-FTIR may be able to estimate 'intrinsic' pKa values of carboxylic acids, in addition to providing quantitative estimates of ionization. ?? 1998 Elsevier Science B.V. All rights reserved.

  3. Identifying Raman and Infrared Vibrational Motions of Erythritol Tetranitrate.

    PubMed

    Oleske, Jeffrey B; Smith, Barry T; Barber, Jeffrey; Weatherall, James C

    2015-12-01

    The vibrational bands of erythritol tetranitrate (ETN) were measured experimentally with both Raman spectroscopy and attenuated total reflectance Fourier transform infrared (ATR FT-IR) spectroscopy. Seventy-two (3N-6) vibrational modes were predicted for ETN using density functional theory calculations performed using the B3LYP/6-31G* density functional basis set and geometry optimization. Raman spectroscopy and ATR FT-IR were used to measure observable Raman and IR signatures between 140 and 3100 wavenumbers (cm(-1)). Within this spectral range, 32 Raman bands and 21 IR bands were measured and identified by their predicted vibrational motion. The spectroscopic and theoretical analysis of ETN performed will advance the detection and identification capabilities of field measuring instruments for this explosive. PMID:26647149

  4. Rheo-attenuated total reflectance infrared spectroscopy: a new tool to study biopolymers.

    PubMed

    Boulet-Audet, Maxime; Vollrath, Fritz; Holland, Chris

    2011-03-01

    Whilst rheology is the reference technique to study the mechanical properties of unspun silk, we know little of the structure and the dynamics that generate them. By coupling infrared spectroscopy and shearing forces to study silk fibroin conversion, we are introducing a novel tool to address this gap in our knowledge. Here the silk conversion process has been studied dynamically using polarized attenuated total reflectance Fourier transform infrared spectroscopy whilst applying shear, thus revealing silk protein conformation and molecular orientation in situ. Our results show that the silk conversion process starts with a pre-alignment of the proteins followed by a rapid growth of the β-sheet formation and then a subsequent deceleration of the growth. We propose that this tool will provide further insight into not only silk but any biopolymer solution, opening a new window into biological materials.

  5. Infrared Signature of the Cation-π Interaction between Calcite and Aromatic Hydrocarbons.

    PubMed

    Wang, Haitao; Grant, Daniel J; Burns, Peter C; Na, Chongzheng

    2015-06-01

    The cation-π interaction is proposed as an important mechanism for the adsorption of aromatic hydrocarbons having non-zero quadrupole moments by mineral surfaces. Direct evidence supporting such a mechanism is, however, limited. Using the model mineral calcite, we probe the cation-π interaction with adsorbed benzene, toluene, and ethylbenzene (BTE) molecules using attenuated total reflectance Fourier transform infrared spectroscopy. We show that the presence of calcite increases the energy required to excite the synchronized bending of aromatic C-H bonds of BTE molecules. The unique conformation of this vibrational mode indicates that the planar aromatic rings of BTE molecules are constrained in a tilted face-down position by the cation-π interaction, as further confirmed by density functional theory calculations. Our results suggest that the shift of the excitation energy of the aromatic C-H bending may be used as an infrared signature for the cation-π interaction occurring on mineral surfaces.

  6. First direct body fat content measurement during pregnancy using Fourier transform near-infrared spectroscopy.

    PubMed

    Azizian, Hormoz; Kramer, John K G; Phillips, Stuart M

    2014-01-01

    Currently, there are no direct and reliable methods to measure the body fat content of women during pregnancy. Estimates of fat accretion can significantly affect calculations of energy requirements. We report here the first direct measurement of determining the body fat content of two women during pregnancy using the Fourier transform near-infrared spectroscopy (FT-NIR) method. Fourier transform near-infrared spectroscopy was shown to provide comparable results to dual-energy X-ray absorptiometry and magnetic resonance imaging. These latter methods, even though very reliable to measure body fat levels, cannot be used to measure the body fat of women during pregnancy because of health concerns, while FT-NIR poses no health risk. The FT-NIR results showed the percent body fat remained relatively constant throughout pregnancy, but fat mass and fat free mass increased. Fat mass followed an S curve with a maximum increase between 15 to 25 weeks of gestation that was only detected by repeated measurements using the FT-NIR technique. These results demonstrate the value of the FT-NIR method to directly measure the fat content of pregnant women in minutes instead of relying on indirect calculations or taking measurements before and after pregnancy to track gestational fat mass accretion.

  7. Quantitative diffuse reflectance infrared fourier transform spectrometric studies of cementitious blends

    SciTech Connect

    Rebagay, T.V.; Dodd, D.A.

    1989-07-01

    The effective immobilization of low-level radioactive liquid wastes in the form of grout depends on the quality of the dry cementitious blends used in the grout formulation. Variation in the mix ratios of the components of the blend can cause detrimental effects on the processing behavior of the grout slurry and the final properties of the cured grout. Thus the blends require thorough chemical characterization and monitoring by strict quality control protocols. In an earlier work at our laboratories, Fourier transform infrared- transmission method has been successfully applied in the analysis of blends of cement, fly ash, and clays. However, this method involved time-consuming sample preparation resulting in slow turnaround for repetitive sampling. A practical approach to quality control required a fast and simple method for the analysis of the blends. This paper describes a diffuse reflectance infrared Fourier transform (DRIFT) spectrometric procedure for the routine examination of neat blends consisting of cement, fly ash, clays and/or blast furnace slags. (1 ref., 10 figs., 4 tabs.)

  8. Identification of Propionibacteria to the species level using Fourier transform infrared spectroscopy and artificial neural networks.

    PubMed

    Dziuba, B

    2013-01-01

    Fourier transform infrared spectroscopy (FTIR) and artificial neural networks (ANN's) were used to identify species of Propionibacteria strains. The aim of the study was to improve the methodology to identify species of Propionibacteria strains, in which the differentiation index D, calculated based on Pearson's correlation and cluster analyses were used to describe the correlation between the Fourier transform infrared spectra and bacteria as molecular systems brought unsatisfactory results. More advanced statistical methods of identification of the FTIR spectra with application of artificial neural networks (ANN's) were used. In this experiment, the FTIR spectra of Propionibacteria strains stored in the library were used to develop artificial neural networks for their identification. Several multilayer perceptrons (MLP) and probabilistic neural networks (PNN) were tested. The practical value of selected artificial neural networks was assessed based on identification results of spectra of 9 reference strains and 28 isolates. To verify results of isolates identification, the PCR based method with the pairs of species-specific primers was used. The use of artificial neural networks in FTIR spectral analyses as the most advanced chemometric method supported correct identification of 93% bacteria of the genus Propionibacterium to the species level.

  9. Fusion of infrared polarization and intensity images using support value transform and fuzzy combination rules

    NASA Astrophysics Data System (ADS)

    Yang, Fengbao; Wei, Hong

    2013-09-01

    Infrared polarization and intensity imagery provide complementary and discriminative information in image understanding and interpretation. In this paper, a novel fusion method is proposed by effectively merging the information with various combination rules. It makes use of both low-frequency and high-frequency images components from support value transform (SVT), and applies fuzzy logic in the combination process. Images (both infrared polarization and intensity images) to be fused are firstly decomposed into low-frequency component images and support value image sequences by the SVT. Then the low-frequency component images are combined using a fuzzy combination rule blending three sub-combination methods of (1) region feature maximum, (2) region feature weighting average, and (3) pixel value maximum; and the support value image sequences are merged using a fuzzy combination rule fusing two sub-combination methods of (1) pixel energy maximum and (2) region feature weighting. With the variables of two newly defined features, i.e. the low-frequency difference feature for low-frequency component images and the support-value difference feature for support value image sequences, trapezoidal membership functions are proposed and developed in tuning the fuzzy fusion process. Finally the fused image is obtained by inverse SVT operations. Experimental results of visual inspection and quantitative evaluation both indicate the superiority of the proposed method to its counterparts in image fusion of infrared polarization and intensity images.

  10. The applicability of Fourier transform infrared (FT-IR) spectroscopy in waste management

    SciTech Connect

    Smidt, Ena . E-mail: ena.smidt@boku.ac.at; Meissl, Katharina

    2007-07-01

    State and stability or reactivity of waste materials are important properties that must be determined to obtain information about the future behavior and the emission potential of the materials. Different chemical and biological parameters are used to describe the stage of organic matter in waste materials. Fourier transform infrared spectroscopy provides information about the chemistry of waste materials in a general way. Several indicator bands that are referred to functional groups represent components or metabolic products. Their presence and intensity or their absence shed light on the phase of degradation or stabilization. The rapid assessment of the stage of organic matter decomposition is a very important field of application. Therefore, infrared spectroscopy is an appropriate tool for process and quality control, for the assessment of abandoned landfills and for checking of the successful landfill remediation. A wide range of applications are presented in this study for different waste materials. Progressing stages of a typical yard/kitchen waste composting process are shown. The fate of anaerobically 'stabilized' leftovers in a subsequent liquid aerobic process is revealed by spectroscopic characteristics. A compost that underwent the biological stabilization process is distinguished from a 'substrate' that comprises immature biogenic waste mixed with mineral compounds. Infrared spectra of freeze-dried leachate from untreated and aerated landfill material prove the effect of the aerobic treatment during 10 weeks in laboratory-scale experiments.

  11. Fourier transform infrared imaging spectroscopy analysis of collagenase-induced cartilage degradation.

    PubMed

    West, P A; Torzilli, P A; Chen, C; Lin, P; Camacho, N P

    2005-01-01

    Collagenase treatment of cartilage serves as an in vitro model of the pathological collagen degradation that occurs in the disease osteoarthritis (OA). Fourier transform infrared imaging spectroscopic (FT-IRIS) analysis of collagenase-treated cartilage is performed to elucidate the molecular origin of the spectral changes previously found at the articular surface of human OA cartilage. Bovine cartilage explants are treated with 0.1% collagenase for 0, 15, or 30 min. In situ collagen cleavage is assessed using immunofluorescent staining with an antibody specific for broken type II collagen. The FT-IRIS analysis of the control and treated specimens mirrors the differences previously found between normal and OA cartilage using an infrared fiber optic probe (IFOP). With collagenase treatment, the amide II/1338 cm(-1) area ratio increases while the 1238 cm(-1)/1227 cm(-1) peak ratio decreases. In addition, polarized FT-IRIS demonstrates a more random orientation of the collagen fibrils that correlate spatially with the immunofluorescent-determined regions of broken type II collagen. We can therefore conclude that the spectral changes observed in the collagenase-treated cartilage, and similarly in OA cartilage, arise from changes in collagen structure. These findings support the use of mid-infrared spectral analysis, in particular the minimally invasive IFOP, as potential techniques for the diagnosis and management of degenerative joint diseases such as osteoarthritis.

  12. A simple method to fabricate lenses for in situ Fourier transform infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Treffman, Lia M.; Morrison, Philip W., Jr.

    1996-04-01

    A process has been developed to hand grind and polish infrared KBr lenses with a wide choice of focal lengths. These lenses are designed for coupling the infrared (IR) beam from a Fourier transform infrared spectrometer into a hot filament chemical vapor deposition reactor. These IR lenses are ground using a glass lens as a mold; the mold lens is a commercial glass lens used for spectacles and is available in a wide range of focal lengths. Rough grinding begins with ♯100 sandpaper and followed by a sequence of fine grinding steps under ethanol: ♯400 SiC powder, ♯600 SiC powder, and emery powder. Polishing is done with a CeO slurry in water followed by a chamois cloth moistened with ethanol. As an indication of the surface finish of the lenses, a flat KBr window that is hand ground and polished in the above manner has a transmission of ≳89% at 8000 cm-1 and ≳91% at 500 cm-1; the commercially polished KBr window has a transmittance of 92% throughout this spectral range.

  13. Use of an endoscope-compatible probe to detect colonic dysplasia with Fourier transform infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Mackanos, Mark A.; Hargrove, John; Wolters, Rolf; Du, Christine B.; Friedland, Shai; Soetikno, Roy M.; Contag, Christopher H.; Arroyo, May R.; Crawford, James M.; Wang, Thomas D.

    2009-07-01

    Fourier transform infrared (FTIR) spectroscopy is sensitive to the molecular composition of tissue and has the potential to identify premalignant tissue (dysplasia) as an adjunct to endoscopy. We demonstrate collection of mid-infrared absorption spectra with a silver halide (AgCl0.4Br0.6) optical fiber and use spectral preprocessing to identify optimal subranges that classify colonic mucosa as normal, hyperplasia, or dysplasia. We collected spectra (n=83) in the 950 to 1800 cm-1 regime on biopsy specimens obtained from human subjects (n=37). Subtle differences in the magnitude of the absorbance peaks at specific wave numbers were observed. The best double binary algorithm for distinguishing normal-versus-dysplasia and hyperplasia-versus-dysplasia was determined from an exhaustive search of spectral intervals and preprocessing techniques. Partial least squares discriminant analysis was used to classify the spectra using a leave-one-subject-out cross-validation strategy. The results were compared with histology reviewed independently by two gastrointestinal pathologists. The optimal thresholds identified resulted in an overall sensitivity, specificity, accuracy, and positive predictive value of 96%, 92%, 93%, and 82%, respectively. These results indicated that mid-infrared absorption spectra collected remotely with an optical fiber can be used to identify colonic dysplasia with high accuracy, suggesting that continued development of this technique for the early detection of cancer is promising.

  14. Infrared

    NASA Astrophysics Data System (ADS)

    Vollmer, M.

    2013-11-01

    underlying physics. There are now at least six different disciplines that deal with infrared radiation in one form or another, and in one or several different spectral portions of the whole IR range. These are spectroscopy, astronomy, thermal imaging, detector and source development and metrology, as well the field of optical data transmission. Scientists working in these fields range from chemists and astronomers through to physicists and even photographers. This issue presents examples from some of these fields. All the papers—though some of them deal with fundamental or applied research—include interesting elements that make them directly applicable to university-level teaching at the graduate or postgraduate level. Source (e.g. quantum cascade lasers) and detector development (e.g. multispectral sensors), as well as metrology issues and optical data transmission, are omitted since they belong to fundamental research journals. Using a more-or-less arbitrary order according to wavelength range, the issue starts with a paper on the physics of near-infrared photography using consumer product cameras in the spectral range from 800 nm to 1.1 µm [1]. It is followed by a series of three papers dealing with IR imaging in spectral ranges from 3 to 14 µm [2-4]. One of them deals with laboratory courses that may help to characterize the IR camera response [2], the second discusses potential applications for nondestructive testing techniques [3] and the third gives an example of how IR thermal imaging may be used to understand cloud cover of the Earth [4], which is the prerequisite for successful climate modelling. The next two papers cover the vast field of IR spectroscopy [5, 6]. The first of these deals with Fourier transform infrared spectroscopy in the spectral range from 2.5 to 25 µm, studying e.g. ro-vibrational excitations in gases or optical phonon interactions within solids [5]. The second deals mostly with the spectroscopy of liquids such as biofuels and special

  15. Detailed near-infrared study of the `water'-related transformations in silcrete upon heat treatment

    NASA Astrophysics Data System (ADS)

    Schmidt, Patrick; Lauer, Christoph; Buck, Gerald; Miller, Christopher E.; Nickel, Klaus G.

    2016-08-01

    In archaeology, lithic heat treatment is the process of modifying a rock for stone tool production using fire. Although the earliest known cases of heat treatment come from South Africa and involved silcrete, a microcrystalline pedogenic silica rock, its thermal transformations remain poorly understood. We investigate the `water'-related transformations in silcrete using direct transmission near-infrared spectroscopy. We found that SiOH is noticeably lost between 250 and 450 °C and hydroxyl reacts with H2O, part of which is trapped in the structure of the rocks. This water can only be evaporated through heat-induced fracturing at high temperatures, imposing maximum temperatures for silcrete heat treatment of approximately 500 °C. Between 250 and 450 °C new siloxane bonds are formed according to the reaction 2SiOH → Si-O-Si + H2O, which can be expected to transform the rock's mechanical properties. The tolerance of silcrete for relatively fast ramp rates can be explained by its pore volume and low SiOH content, ensuring good water evaporation. These results shed light on the processes taking place in silcrete during heat treatment and allow for a better understanding of the parameters needed for it.

  16. Spectra Transfer Between a Fourier Transform Near-Infrared Laboratory and a Miniaturized Handheld Near-Infrared Spectrometer.

    PubMed

    Hoffmann, Uwe; Pfeifer, Frank; Hsuing, Chang; Siesler, Heinz W

    2016-05-01

    The aim of this contribution is to demonstrate the transfer of spectra that have been measured on two different laboratory Fourier transform near-infrared (FT-NIR) spectrometers to the format of a handheld instrument by measuring only a few samples with both spectrometer types. Thus, despite the extreme differences in spectral range and resolution, spectral data sets that have been collected and quantitative as well as qualitative calibrations that have been developed thereof, respectively, over a long period on a laboratory instrument can be conveniently transferred to the handheld system. Thus, the necessity to prepare completely new calibration samples and the effort required to develop calibration models when changing hardware platforms is minimized. The enabling procedure is based on piecewise direct standardization (PDS) and will be described for the data sets of a quantitative and a qualitative application case study. For this purpose the spectra measured on the FT-NIR laboratory spectrometers were used as "master" data and transferred to the "target" format of the handheld instrument. The quantitative test study refers to transmission spectra of three-component liquid solvent mixtures whereas the qualitative application example encompasses diffuse reflection spectra of six different current polymers. To prove the performance of the transfer procedure for quantitative applications, partial least squares (PLS-1) calibrations were developed for the individual components of the solvent mixtures with spectra transferred from the master to the target instrument and the cross-validation parameters were compared with the corresponding parameters obtained for spectra measured on the master and target instruments, respectively. To test the retention of the discrimination ability of the transferred polymer spectra sets principal component analyses (PCAs) were applied exemplarily for three of the six investigated polymers and their identification was demonstrated by

  17. Biochemical differentiation of mycelium and yeast forms of Paracoccidioides brasiliensis by Fourier transform infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Castilho, Maiara L.; Campos, Claudia B. L.; Matos, Tatiana G. F.; de Abreu, Geraldo M. A.; Martin, Airton A.; Raniero, Leandro

    2012-01-01

    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). The most prominent difference between both forms is probably the cell wall polysaccharide, being 1,3-β-glucan usually found in mycelia and 1,3-α-glucan found in yeasts, but a plethora of other differences have already been described. In this work, we performed a Fourier Transform Infrared Spectroscopy analysis to compare the yeast and mycelia forms of P. brasiliensis and found additional biochemical differences. The analysis of the spectra showed that differences were distributed in chemical bonds of proteins, lipids and carbohydrates.

  18. Fourier transform mid infrared spectroscopy applications for monitoring the structural plasticity of plant cell walls

    PubMed Central

    Largo-Gosens, Asier; Hernández-Altamirano, Mabel; García-Calvo, Laura; Alonso-Simón, Ana; Álvarez, Jesús; Acebes, José L.

    2014-01-01

    Fourier transform mid-infrared (FT-MIR) spectroscopy has been extensively used as a potent, fast and non-destructive procedure for analyzing cell wall architectures, with the capacity to provide abundant information about their polymers, functional groups, and in muro entanglement. In conjunction with multivariate analyses, this method has proved to be a valuable tool for tracking alterations in cell walls. The present review examines recent progress in the use of FT-MIR spectroscopy to monitor cell wall changes occurring in muro as a result of various factors, such as growth and development processes, genetic modifications, exposition or habituation to cellulose biosynthesis inhibitors and responses to other abiotic or biotic stresses, as well as its biotechnological applications. PMID:25071791

  19. Chemically functionalized carbon nanotubes and their characterization using thermogravimetric analysis, fourier transform infrared, and raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Titus, E.; Ali, N.; Cabral, G.; Gracio, J.; Ramesh Babu, P.; Jackson, M. J.

    2006-04-01

    This article reports key findings on the chemical functionalization of carbon nanotubes (CNT). The functionalization of chemical vapor-deposited CNT was carried out by treating tubes with polyvinyl alcohol through ultrasonication in water with the aid of a surfactant. The surfactant is expected to promote the unbundling of aggregated CNT. The characterization of functionalized samples using thermogravimetric analysis, Fourier transform infrared spectroscopy, and Raman spectroscopy revealed that the CNT were functionalized by the interaction of carboxylic acid and hydroxyl groups. From the characterization studies, it is apparent that there is a strong interaction between these functional groups and the covalently bonded carbon in the CNT network. The functionalization process enabled good CNT dispersion in the solution, and the CNT remained in suspension for many days. To support the effective functionalization of the tubes, the interaction of functionalized CNT with Ni ions is also demonstrated.

  20. Quantitative analysis of virgin coconut oil in cream cosmetics preparations using fourier transform infrared (FTIR) spectroscopy.

    PubMed

    Rohman, A; Man, Yb Che; Sismindari

    2009-10-01

    Today, virgin coconut oil (VCO) is becoming valuable oil and is receiving an attractive topic for researchers because of its several biological activities. In cosmetics industry, VCO is excellent material which functions as a skin moisturizer and softener. Therefore, it is important to develop a quantitative analytical method offering a fast and reliable technique. Fourier transform infrared (FTIR) spectroscopy with sample handling technique of attenuated total reflectance (ATR) can be successfully used to analyze VCO quantitatively in cream cosmetic preparations. A multivariate analysis using calibration of partial least square (PLS) model revealed the good relationship between actual value and FTIR-predicted value of VCO with coefficient of determination (R2) of 0.998.

  1. Bivariate distribution, correlation, and transformation properties of two-color infrared systems.

    PubMed

    Clow, R; McNolty, F

    1974-05-01

    A two-dimensional (two-color) statistical structure is formulated that is applicable to pattern recognition, discrimination, and detection problems occurring in infrared signal-processing systems. The methodology relates physical quantities such as the temperature T of an object, its projected area A, emissivity , range R from the sensor, and noise equivalent flux density (NEFD) to the geometry of a local orthogonal coordinate system where the coordinate axes correspond to the apparent radiant intensity J in each micron bandwidth. The bivariate distribution, correlation, and transformation properties attendant to this framework are discussed in detail. Additional insight into the structure of the problem is achieved by investigating the two-color system in terms of a nonorthogonal local coordinate system. The various results presented in the paper may be extended to three-, four-, or five-color systems by direct analogies.

  2. Geographical traceability of Marsdenia tenacissima by Fourier transform infrared spectroscopy and chemometrics

    NASA Astrophysics Data System (ADS)

    Li, Chao; Yang, Sheng-Chao; Guo, Qiao-Sheng; Zheng, Kai-Yan; Wang, Ping-Li; Meng, Zhen-Gui

    2016-01-01

    A combination of Fourier transform infrared spectroscopy with chemometrics tools provided an approach for studying Marsdenia tenacissima according to its geographical origin. A total of 128 M. tenacissima samples from four provinces in China were analyzed with FTIR spectroscopy. Six pattern recognition methods were used to construct the discrimination models: support vector machine-genetic algorithms, support vector machine-particle swarm optimization, K-nearest neighbors, radial basis function neural network, random forest and support vector machine-grid search. Experimental results showed that K-nearest neighbors was superior to other mathematical algorithms after data were preprocessed with wavelet de-noising, with a discrimination rate of 100% in both the training and prediction sets. This study demonstrated that FTIR spectroscopy coupled with K-nearest neighbors could be successfully applied to determine the geographical origins of M. tenacissima samples, thereby providing reliable authentication in a rapid, cheap and noninvasive way.

  3. Detection of sugar adulterants in apple juice using fourier transform infrared spectroscopy and chemometrics.

    PubMed

    Kelly, J F Daniel; Downey, Gerard

    2005-05-01

    Fourier transform infrared spectroscopy and attenuated total reflection sampling have been used to detect adulteration of single strength apple juice samples. The sample set comprised 224 authentic apple juices and 480 adulterated samples. Adulterants used included partially inverted cane syrup (PICS), beet sucrose (BS), high fructose corn syrup (HFCS), and a synthetic solution of fructose, glucose, and sucrose (FGS). Adulteration was carried out on individual apple juice samples at levels of 10, 20, 30, and 40% w/w. Spectral data were compressed by principal component analysis and analyzed using k-nearest neighbors and partial least squares regression techniques. Prediction results for the best classification models achieved an overall (authentic plus adulterated) correct classification rate of 96.5, 93.9, 92.2, and 82.4% for PICS, BS, HFCS, and FGS adulterants, respectively. This method shows promise as a rapid screening technique for the detection of a broad range of potential adulterants in apple juice.

  4. Imaging open-path Fourier transform infrared spectrometer for 3D cloud profiling

    NASA Astrophysics Data System (ADS)

    Rentz Dupuis, Julia; Mansur, David J.; Engel, James R.; Vaillancourt, Robert; Todd, Lori; Mottus, Kathleen

    2008-04-01

    OPTRA and University of North Carolina are developing an imaging open-path Fourier transform infrared (I-OP-FTIR) spectrometer for 3D profiling of chemical and biological agent simulant plumes released into test ranges and chambers. An array of I-OP-FTIR instruments positioned around the perimeter of the test site, in concert with advanced spectroscopic algorithms, enables real time tomographic reconstruction of the plume. The approach will be considered as a candidate referee measurement for test ranges and chambers. This Small Business Technology Transfer (STTR) effort combines the instrumentation and spectroscopic capabilities of OPTRA, Inc. with the computed tomographic expertise of the University of North Carolina, Chapel Hill. In this paper, we summarize progress to date and overall system performance projections based on the instrument, spectroscopy, and tomographic reconstruction accuracy. We then present a preliminary optical design of the I-OP-FTIR.

  5. Imaging open-path Fourier transform infrared spectrometer for 3D cloud profiling

    NASA Astrophysics Data System (ADS)

    Rentz Dupuis, Julia; Mansur, David J.; Vaillancourt, Robert; Carlson, David; Evans, Thomas; Schundler, Elizabeth; Todd, Lori; Mottus, Kathleen

    2010-04-01

    OPTRA has developed an imaging open-path Fourier transform infrared (I-OP-FTIR) spectrometer for 3D profiling of chemical and biological agent simulant plumes released into test ranges and chambers. An array of I-OP-FTIR instruments positioned around the perimeter of the test site, in concert with advanced spectroscopic algorithms, enables real time tomographic reconstruction of the plume. The approach is intended as a referee measurement for test ranges and chambers. This Small Business Technology Transfer (STTR) effort combines the instrumentation and spectroscopic capabilities of OPTRA, Inc. with the computed tomographic expertise of the University of North Carolina, Chapel Hill. In this paper, we summarize the design and build and detail system characterization and test of a prototype I-OP-FTIR instrument. System characterization includes radiometric performance and spectral resolution. Results from a series of tomographic reconstructions of sulfur hexafluoride plumes in a laboratory setting are also presented.

  6. Quantitative Fourier transform infrared analysis of gas phase cigarette smoke and other gas mixtures

    SciTech Connect

    Cueto, R.; Church, D.F.; Pryor, W.A. )

    1989-03-01

    A new method for the analysis of selected components in complex gas mixtures has been developed utilizing a relatively inexpensive Fourier transform infrared spectrometer and a continuous flow gas cell. The method was used to monitor nitric oxide and nitrogen dioxide concentrations in cigarette smoke with time. Using multivariate least-square regression analysis, it is possible to simultaneously quantitate both NO and NO{sub 2}, even in the presence of overlapping peaks. Using this method, the oxidation of nitric oxide in the presence of isoprene in cigarette smoke and in a model system was followed with time. The method also can be applied to other compounds in smoke or to any other gaseous mixture.

  7. Identification of Trueperella pyogenes Isolated from Bovine Mastitis by Fourier Transform Infrared Spectroscopy

    PubMed Central

    Nagib, Samy; Rau, Jörg; Sammra, Osama; Lämmler, Christoph; Schlez, Karen; Zschöck, Michael; Prenger-Berninghoff, Ellen; Klein, Guenter; Abdulmawjood, Amir

    2014-01-01

    The present study was designed to investigate the potential of Fourier transform infrared (FT-IR) spectroscopy to identify Trueperella (T.) pyogenes isolated from bovine clinical mastitis. FT-IR spectroscopy was applied to 57 isolates obtained from 55 cows in a period from 2009 to 2012. Prior to FT-IR spectroscopy these isolates were identified by phenotypic and genotypic properties, also including the determination of seven potential virulence factor encoding genes. The FT-IR analysis revealed a reliable identification of all 57 isolates as T. pyogenes and a clear separation of this species from the other species of genus Trueperella and from species of genus Arcanobacterium and Actinomyces. The results showed that all 57 isolates were assigned to the correct species indicating that FT-IR spectroscopy could also be efficiently used for identification of this bacterial pathogen. PMID:25133407

  8. Evaluation of a FTIR (Fourier Transform Infrared Spectrometer) mobile source measurement system

    NASA Astrophysics Data System (ADS)

    Sigsby, John E., Jr.; McArver, Alex; Snow, Richard

    1989-04-01

    An initial evaluation was made of a prototype Fourier transform infrared spectrometer on its ability to measure mobile source emissions. This prototype represents the commercialization of research technology developed by the Ford Motor Co. The system utilizes a Mattson Instruments Co. interferometer coupled to a Masscomp computer. The required software is still incomplete. This has resulted in the inability to correct errors or optimize results. Unreliability of both hardware and software is a major shortcoming of the system. When operating properly, the system measures carbon dioxide, nitric oxide, and formaldehyde accurately, both when compared to bag analysis and on direct point-by-point comparisons with real-time data. Completion of the evaluation awaits the final software translations and improvements in reliability.

  9. Oxidation of ultrahigh molecular weight polyethylene characterized by Fourier Transform Infrared Spectrometry.

    PubMed

    Goldman, M; Lee, M; Gronsky, R; Pruitt, L

    1997-10-01

    The effects of processing conditions, sterilization treatment, aging time, and poststerilization aging environment on the oxidation behavior of ultrahigh molecular weight polyethylene (UHMWPE) are examined. Oxidation is monitored by observing changes in the carbonyl peak appearing in Fourier Transform Infrared Spectrometry (FTIR) and is found to be relatively insensitive to processing conditions but strongly influenced by sterilization treatments and aging parameters. Oxygen uptake by UHMWPE increases as a result of gamma or electron beam irradiation and continues to rise during subsequent aging at a rate influenced by the aging environment. A hydrogen peroxide ambient causes more severe oxidation than either air or hyaluronic acid. Control (unsterilized) samples and those sterilized in ethylene oxide are resistant to oxidation under all conditions except hydrogen peroxide aging.

  10. Automated cervical precancerous cells screening system based on Fourier transform infrared spectroscopy features

    NASA Astrophysics Data System (ADS)

    Jusman, Yessi; Mat Isa, Nor Ashidi; Ng, Siew-Cheok; Hasikin, Khairunnisa; Abu Osman, Noor Azuan

    2016-07-01

    Fourier transform infrared (FTIR) spectroscopy technique can detect the abnormality of a cervical cell that occurs before the morphological change could be observed under the light microscope as employed in conventional techniques. This paper presents developed features extraction for an automated screening system for cervical precancerous cell based on the FTIR spectroscopy as a second opinion to pathologists. The automated system generally consists of the developed features extraction and classification stages. Signal processing techniques are used in the features extraction stage. Then, discriminant analysis and principal component analysis are employed to select dominant features for the classification process. The datasets of the cervical precancerous cells obtained from the feature selection process are classified using a hybrid multilayered perceptron network. The proposed system achieved 92% accuracy.

  11. Fourier transform infrared method validation at a carbon bed solvent recovery unit for four gaseous hydrocarbons

    SciTech Connect

    Reagen, W.K.; Wright, B.D.; Krueger, D.J.; Plummer, G.M.

    1999-05-15

    The authors report the results of a 1995 study in which Fourier transform infrared (FTIR) gas-phase spectrometry was employed to measure the concentrations of four organic compounds (tetrahydrofuran, toluene, 2-butanone, and cyclohexanone) in the gas stream of an industrial solvent recovery unit. The goals of the study were to demonstrate that the extractive FTIR technique is (1) suitable for compliance measurements of the four individual compound concentrations and (2) an accurate substitute for flame ionization detection determinations of the total hydrocarbon content of the gas stream. The US Environmental Protection Agency (EPA) provides guidance on this type of study in its Method 301, which lists specific procedures and statistical criteria, and in several recently published documents describing FTIR quality assurance/quality control measures. The EPA reviews of the procedures and results indicate that both goals of the study were met according to EPA standards.

  12. Fourier transform infrared imaging analysis in discrimination studies of St. John's wort (Hypericum perforatum).

    PubMed

    Huck-Pezzei, V A; Pallua, J D; Pezzei, C; Bittner, L K; Schönbichler, S A; Abel, G; Popp, M; Bonn, G K; Huck, C W

    2012-10-01

    In the present study, Fourier transform infrared (FTIR) imaging and data analysis methods were combined to study morphological and molecular patterns of St. John's wort (Hypericum perforatum) in detail. For interpretation, FTIR imaging results were correlated with histological information gained from light microscopy (LM). Additionally, we tested several evaluation processes and optimized the methodology for use of complex FTIR microscopic images to monitor molecular patterns. It is demonstrated that the combination of the used spectroscopic method with LM enables a more distinct picture, concerning morphology and distribution of active ingredients, to be gained. We were able to obtain high-quality FTIR microscopic imaging results and to distinguish different tissue types with their chemical ingredients.

  13. Fourier transform infrared and Raman spectroscopy studies on magnetite/Ag/antibiotic nanocomposites

    NASA Astrophysics Data System (ADS)

    Ivashchenko, Olena; Jurga-Stopa, Justyna; Coy, Emerson; Peplinska, Barbara; Pietralik, Zuzanna; Jurga, Stefan

    2016-02-01

    This article presents a study on the detection of antibiotics in magnetite/Ag/antibiotic nanocomposites using Fourier transform infrared (FTIR) and Raman spectroscopy. Antibiotics with different spectra of antimicrobial activities, including rifampicin, doxycycline, cefotaxime, and ceftriaxone, were studied. Mechanical mixtures of antibiotics and magnetite/Ag nanocomposites, as well as antibiotics and magnetite nanopowder, were investigated in order to identify the origin of FTIR bands. FTIR spectroscopy was found to be an appropriate technique for this task. The spectra of the magnetite/Ag/antibiotic nanocomposites exhibited very weak (for doxycycline, cefotaxime, and ceftriaxone) or even no (for rifampicin) antibiotic bands. This FTIR "invisibility" of antibiotics is ascribed to their adsorbed state. FTIR and Raman measurements show altered Csbnd O, Cdbnd O, and Csbnd S bonds, indicating adsorption of the antibiotic molecules on the magnetite/Ag nanocomposite structure. In addition, a potential mechanism through which antibiotic molecules interact with magnetite/Ag nanoparticle surfaces is proposed.

  14. United States Environmental Protection Agency Fourier transform infrared spectroscopy test program for emissions measurement

    SciTech Connect

    Lay, L.T.

    1994-12-31

    The US Environmental Protection Agency (EPA) published amendments to the Clean Air Act (CAA) November 15, 1990. Title 3 of the CAA amendments included a list of 189 hazardous air pollutants (HAPs) for which emission test procedures must be established. An extractive emission test method, using Fourier Transform Infrared (FTIR) spectroscopy, is being developed for measuring HAP compounds. The FTIR procedure has the potential to detect over 100 of the listed compounds plus additional compounds such as criteria pollutants. This procedure has the ability to detect multiple compounds simultaneously and will provide near real-time data. Since the development of the extractive FTIR procedure, many source categories have been screened for HAP emissions using this technique. Modifications to the procedure have been made and validation testing has been performed. Currently, this technique is being used to collect data for maximum achievable control technology (MACT) standard development.

  15. [Combustion temperature measurement of pyrotechnic composition using remote sensing Fourier transform infrared spectrometry].

    PubMed

    Zhou, Xin-li; Li, Yan; Liu, Zu-liang; Zhu, Chang-jiang; Wang, Jun-de; Lu, Chun-xu

    2002-10-01

    In this paper, combustion characterization of pyrotechnic composition is investigated using a remote sensing Fourier transform infrared spectrometry. The emission spectra have been recorded between 4,700 and 740 cm-1 with a spectral resolution of 4 cm-1. The combustion temperature can be determined remotely from spectral line intensity distribution of the fine structure of the emission fundamental band of gaseous products such as HF. The relationship between combustion temperature and combustion time has been given. Results show that there is a violent mutative temperature field with bigger temperature gradient near combustion surface. It reveals that the method of temperature measurement using remote sensing FTIR for flame temperature of unstable, violent and short time combustion on real time is a rapid, accurate and sensitive technique without interference the flame temperature field. Potential prospects of temperature measurement, gas product concentration measurement and combustion mechanism are also revealed.

  16. Microchemical Structure of Soybean Seeds Revealed in Situ by Ultraspatially Resolved Synchrotron Fourier Transformed Infrared Microspectroscopy

    SciTech Connect

    Pietrzak,L.; Miller, S.

    2005-01-01

    The distribution of water in soybean seeds during imbibition varies with the chemical composition of the tissue. To understand the dynamics of imbibition, the proteins, lipids, and carbohydrates of the cotyledons and hilum region in mature soybean seeds were mapped using synchrotron Fourier transformed infrared microspectroscopy, based on characteristic peaks for each component: amide I at 1650 cm{sup -1} and amide II at 1550 cm{sup -1} for protein, lipid ester stretch at 1545 cm{sup -1}, and the region from 1200 to 900 cm{sup -1} for carbohydrates. The amount and configuration of the proteins varied across the cotyledon, as well as the amount of lipid and carbohydrate. It was found that protein distribution across the cotyledon is similar to water distribution during imbibition. The chemistry of the hilum region was also studied, as this is the point of water entry, and differences in the chemical composition of the tissues studied were observed.

  17. High resolution infrared spectroscopy of planetary molecules using diode lasers and Fourier transform spectrometers

    NASA Technical Reports Server (NTRS)

    Jennings, Donald E.

    1990-01-01

    Modern observations of infrared molecular lines in planets are performed at spectral resolutions which are as high as those available in the laboratory. Analysis of such data requires laboratory measurements at the highest possible resolution, which also yield accurate line positions and intensities. For planetary purposes the spectrometer must be coupled to sample cells which can be reduced in temperature and varied in pressure. An approach which produces the full range of required molecular line parameters uses a combination of tunable diode lasers and Fourier transform spectrometers (FTS). The FTS provides board spectral coverage and good calibration accuracy, while the diode laser can be used to study those regions which are not resolved by the FTS.

  18. Pectin functionalised by fatty acids: Diffuse reflectance infrared Fourier transform (DRIFT) spectroscopic characterisation

    NASA Astrophysics Data System (ADS)

    Kamnev, Alexander A.; Calce, Enrica; Tarantilis, Petros A.; Tugarova, Anna V.; De Luca, Stefania

    2015-01-01

    Chemically modified pectin derivatives obtained by partial esterification of its hydroxyl moieties with fatty acids (FA; oleic, linoleic and palmitic acids), as well as the initial apple peel pectin were comparatively characterised using diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy. Characteristic changes observed in DRIFT spectra in going from pectin to its FA esters are related to the corresponding chemical modifications. Comparing the DRIFT spectra with some reported data on FTIR spectra of the same materials measured in KBr or NaCl matrices has revealed noticeable shifts of several polar functional groups both in pectin and in its FA-esterified products induced by the halide salts. The results obtained have implications for careful structural analyses of biopolymers with hydrophilic functional groups by means of different FTIR spectroscopic methodologies.

  19. Differentiation and detection of microorganisms using Fourier transform infrared photoacoustic spectroscopy

    NASA Astrophysics Data System (ADS)

    Irudayaraj, Joseph; Yang, Hong; Sakhamuri, Sivakesava

    2002-03-01

    Fourier transform infrared photoacoustic spectroscopy (FTIR-PAS) was used to differentiate and identify microorganisms on a food (apple) surface. Microorganisms considered include bacteria ( Lactobacillus casei, Bacillus cereus, and Escherichia coli), yeast ( Saccharomyces cerevisiae), and fungi ( Aspergillus niger and Fusarium verticilliodes). Discriminant analysis was used to differentiate apples contaminated with the different microorganisms from uncontaminated apple. Mahalanobis distances were calculated to quantify the differences. The higher the value of the Mahalanobis distance metric between different microorganisms, the greater is their difference. Additionally, pathogenic (O157:H7) E. coli was successfully differentiated from non-pathogenic strains. Results demonstrate that FTIR-PAS spectroscopy has the potential to become a non-destructive analysis tool in food safety related research.

  20. Reducing inter-replicate variation in fourier transform infrared spectroscopy by extended multiplicative signal correction.

    PubMed

    Kohler, A; Böcker, U; Warringer, J; Blomberg, A; Omholt, S W; Stark, E; Martens, H

    2009-03-01

    Fourier transform infrared (FT-IR) spectroscopy is a powerful tool for characterizing biological tissues and organisms, but it is plagued by replicate variation of various sources. Here, a method for estimating and correcting unwanted replicate variation in multivariate measurement signals, based on extended multiplicative signal correction (EMSC), is presented. Systematic patterns of unwanted methodological variations are estimated from replicate spectra, modeled by a linear subspace model, and implemented into EMSC. The method is applied to FT-IR spectra of two different sets of microorganisms (different double gene knockout strains of Saccharomyces cerevisiae and different species of Listeria) and compared to other preprocessing methods used in FT-IR absorption spectroscopy of microorganisms. The EMSC replicate correction turns out to perform best among the compared methods.

  1. Microchemical structure of soybean seeds revealed in situ by ultraspatially resolved synchrotron Fourier transformed infrared microspectroscopy.

    PubMed

    Pietrzak, Lukasz N; Miller, S Shea

    2005-11-30

    The distribution of water in soybean seeds during imbibition varies with the chemical composition of the tissue. To understand the dynamics of imbibition, the proteins, lipids, and carbohydrates of the cotyledons and hilum region in mature soybean seeds were mapped using synchrotron Fourier transformed infrared microspectroscopy, based on characteristic peaks for each component: amide I at 1650 cm(-1) and amide II at 1550 cm(-1) for protein, lipid ester stretch at 1545 cm(-1), and the region from 1200 to 900 cm(-1) for carbohydrates. The amount and configuration of the proteins varied across the cotyledon, as well as the amount of lipid and carbohydrate. It was found that protein distribution across the cotyledon is similar to water distribution during imbibition. The chemistry of the hilum region was also studied, as this is the point of water entry, and differences in the chemical composition of the tissues studied were observed.

  2. High-definition Fourier transform infrared spectroscopic imaging of prostate tissue

    NASA Astrophysics Data System (ADS)

    Wrobel, Tomasz P.; Kwak, Jin Tae; Kadjacsy-Balla, Andre; Bhargava, Rohit

    2016-03-01

    Histopathology forms the gold standard for cancer diagnosis and therapy, and generally relies on manual examination of microscopic structural morphology within tissue. Fourier-Transform Infrared (FT-IR) imaging is an emerging vibrational spectroscopic imaging technique, especially in a High-Definition (HD) format, that provides the spatial specificity of microscopy at magnifications used in diagnostic surgical pathology. While it has been shown for standard imaging that IR absorption by tissue creates a strong signal where the spectrum at each pixel is a quantitative "fingerprint" of the molecular composition of the sample, here we show that this fingerprint also enables direct digital pathology without the need for stains or dyes for HD imaging. An assessment of the potential of HD imaging to improve diagnostic pathology accuracy is presented.

  3. Histopathology mapping of biochemical changes in myocardial infarction by Fourier transform infrared spectral imaging.

    PubMed

    Yang, Tian T; Weng, Shi F; Zheng, Na; Pan, Qing H; Cao, Hong L; Liu, Liang; Zhang, Hai D; Mu, Da W

    2011-04-15

    Fourier transform infrared (FTIR) imaging and microspectroscopy have been extensively applied in the identification and investigation of both healthy and diseased tissues. FTIR imaging can be used to determine the biodistribution of several molecules of interest (carbohydrates, lipids, proteins) for tissue analysis, without the need for prior staining of these tissues. Molecular structure data, such as protein secondary structure and collagen triple helix exhibits, can also be obtained from the same analysis. Thus, several histopathological lesions, for example myocardial infarction, can be identified from FTIR-analyzed tissue images, the latter which can allow for more accurate discrimination between healthy tissues and pathological lesions. Accordingly, we propose FTIR imaging as a new tool integrating both molecular and histopathological assessment to investigate the degree of pathological changes in tissues. In this study, myocardial infarction is presented as an illustrative example of the wide potential of FTIR imaging for biomedical applications.

  4. Study of Fourier transform infrared spectra of cockroach nervous tissue and chitin

    NASA Astrophysics Data System (ADS)

    Ghadage, Vijay H.; Kulkarni, Gauri R.; Bhoraskar, Sudha V.

    2012-03-01

    Fourier Transform Infrared Spectroscopy (FTIR) is a very sensitive tool which is capable of providing strong insight on structural and functional changes in lipids and proteins induced by laser radiation. In the present work cockroach nervous tissue and chitin from tibia region are irradiated with Nd: YAG laser (λ= 1064 nm, Power =150mW) via fiber optics (Numerical aperture=0.22, diameter = 8 μ). Nd: YAG laser exposure time is varied from 10 sec to 50 sec for nervous tissue and chitin. FTIR (Fourier Transform Infra Red spectra) of cockroach nervous tissue and chitin are compared before and after laser irradiation. The FTIR spectrum of non irradiated cockroach nervous tissue shows clearly the peaks due to O-H (Carboxylic acid), C=O (Amide I), C=C (Aromatic), N=0 (Nitro), C-H (Alkenes), CH (Aromatics). FTIR Spectra of non irradiated cockroach chitin clearly shows O-H (Carboxylic acid), C=O (Carbonyl stretch), C=C (Aromatic), N=O (Nitro), C-O, (anhydrides), C-H (Alkenes stretch) group. FTIR spectra of laser radiated nervous tissue from cockroach tibia and chitin shows significant changes in transmittance for O-H, C=O, C=C, C-H, N=O, C-O and C-H groups. The percentage transmittance increases for O-H, C=C group for exposure time 10sec, 40sec and 50 sec for nervous tissue. The percentage transmittance increases for O-H, C=C group for exposure time 10sec, 20sec, 30sec and 40 sec for chitin. The study shows clearly that FTIR spectroscopy of nervous tissue can reveal the interactions between infrared laser light and nervous tissue.

  5. Studies on Nephrite and Jadeite Jades by Fourier Transform Infrared (ftir) and Raman Spectroscopic Techniques

    NASA Astrophysics Data System (ADS)

    Tan, T. L.; Ng, L. L.; Lim, L. C.

    2013-10-01

    The mineralogical properties of black nephrite jade from Western Australia are studied by Fourier transform infrared (FTIR) spectroscopy using both transmission and specular reflectance techniques in the 4000-400 cm-1 wavenumber region. The infrared absorption peaks in the 3700-3600 cm-1 region which are due to the O-H stretching mode provides a quantitative analysis of the Fe/(Fe+Mg) ratio in the mineral composition of jade samples. The Fe/(Fe+Mg) percentage in black nephrite is found to be higher than that in green nephrite, but comparable to that of actinolite (iron-rich nephrite). This implies that the mineralogy of black nephrite is closer to actinolite than tremolite. The jade is also characterized using Raman spectroscopy in the 1200-200 cm-1 region. Results from FTIR and Raman spectroscopic data of black nephrite jade are compared with those of green nephrite jade from New Zealand and jadeite jade from Myanmar. Black nephrite appears to have a slightly different chemical composition from green nephrite. Spectra from FTIR and Raman spectroscopic techniques were found to be useful in differentiating black nephrite, green nephrite, and green jadeite jades. Furthermore, data on refractive index, specific gravity, and hardness of black nephrite jade are measured and compared with those of green nephrite and of jadeite jade.

  6. In Situ Fourier transform infrared spectroscopic study of the thermal degradation of isotactic poly(propylene).

    PubMed

    He, Peng; Xiao, Yan; Zhang, Puming; Zhu, Na; Zhu, Xinyuan; Yan, Deyue

    2005-01-01

    The conformational change of isotactic poly(propylene) (iPP) during the thermal degradation process has been carefully studied by in situ Fourier transform infrared (FT-IR) spectroscopy. This new method of studying thermal degradation of iPP not only shows the conventional kinetic parameter information of thermal degradation such as the degradation activation energy DeltaE and the degradation factor n, which are in accord with the results of traditional thermogravimetry experiments, but also indicates that many significant molecular structure changes occur during the thermal degradation process that come from some characteristic absorption band changes of in situ FT-IR. A multivariate approach, principal components analysis (PCA), is applied to the analysis of infrared (IR) data, and the results further confirm the multi-step processes of the thermal degradation of iPP. Above all, this is a new application to polymer thermal degradation by in situ FT-IR that connects the intermediate conformational change with final results during thermal degradation.

  7. a Fourier Transform Infrared Study of Competing Equilibrium in P-Vinyl Phenol) Blends.

    NASA Astrophysics Data System (ADS)

    Lichkus, Andrew Murray

    In this thesis a Fourier transform infrared (FTIR) spectroscopic study of polymer blends containing poly(p -vinyl phenol) (PVPh) is presented. The characteristics of the intermolecular hydrogen bonding arising from the interaction between the phenolic hydroxyl and carbonyl groups of the different polyacrylates are discussed. The experimental work is focussed primarily on the PVPh with polyacrylate blend systems which include poly(methyl acrylate), poly(ethyl acrylate), poly(n-butyl acrylate), poly(n-pentyl acrylate) and poly(2-ethyl-hexyl acrylate). The infrared bands associated with the intermolecular hydrogen bonding between the phenolic hydroxyl and acrylate carbonyl group are identified. The proportion of hydrogen bonded carbonyl groups in these blends is quantified both as a function of composition and temperature. The effect of the pendant group on the extent of the intermolecular interaction is discussed. The experimental results from this study, including those obtained by other workers, are recast into theoretical phase diagrams via the application of an association model describing binary blends involving hydrogen bonds. The phase diagrams are compared with experimental observations and found to be in broad general agreement. The theoretical predictions of the model with respect to the effect of molecular weight and polymer repeat unit size on the predicted phase behavior is discussed. This study confirms that the phase behavior of polymer blends exhibiting hydrogen bonding can be adequately described by a model employing a competing equilibrium scheme which includes an excess free energy function to account for the specific interactions.

  8. Advances in data processing for open-path Fourier transform infrared spectrometry of greenhouse gases.

    PubMed

    Shao, Limin; Griffiths, Peter R; Leytem, April B

    2010-10-01

    The automated quantification of three greenhouse gases, ammonia, methane, and nitrous oxide, in the vicinity of a large dairy farm by open-path Fourier transform infrared (OP/FT-IR) spectrometry at intervals of 5 min is demonstrated. Spectral pretreatment, including the automated detection and correction of the effect of interrupting the infrared beam, is by a moving object, and the automated correction for the nonlinear detector response is applied to the measured interferograms. Two ways of obtaining quantitative data from OP/FT-IR data are described. The first, which is installed in a recently acquired commercial OP/FT-IR spectrometer, is based on classical least-squares (CLS) regression, and the second is based on partial least-squares (PLS) regression. It is shown that CLS regression only gives accurate results if the absorption features of the analytes are located in very short spectral intervals where lines due to atmospheric water vapor are absent or very weak; of the three analytes examined, only ammonia fell into this category. On the other hand, PLS regression works allowed what appeared to be accurate results to be obtained for all three analytes.

  9. Comparison of passive-remote and conventional Fourier transform infrared systems for continuously monitoring incinerator emissions

    SciTech Connect

    Demirgian, J.C.; Hammer, C.L.; Kroutil, R.T.

    1992-07-01

    Significant improvements in detection technology are needed to comply with the requirements in the Clean Air Act of 1990, Title 3, which requires the monitoring of air toxics. Fourier transform infrared (FTIR) spectroscopy can satisfy these requirements in two different modes. Conventional FTIR spectrometers can be installed on-stream so that a vapor stream enters an infrared cell for analysis. Other types of FTIR spectrometers can detect chemical plumes remotely, measure the natural emissions of the molecules in the plume. The samples do not come to the instrument, and the instrument has neither source nor reflector mirrors. We will discuss the applications of FTIR spectrometry for both conventional and passive-remote FTIR spectroscopy. Some applications of conventional FTIR include a continuous emission monitor for measuring incinerator emissions and determining indoor air quality. Passive-remote FTIR spectroscopy can be used to identify and track a chemical plume. It can also be used to detect fugitive emissions. Hence, it can be used as an independent means to assure compliance with environmental regulations in real-time. Because of the relatively simple instrumentation, passive-remote instruments can be helicopter- or vehicle-mounted for mobile detection of plumes.

  10. Comparison of passive-remote and conventional Fourier transform infrared systems for continuously monitoring incinerator emissions

    SciTech Connect

    Demirgian, J.C.; Hammer, C.L. ); Kroutil, R.T. )

    1992-01-01

    Significant improvements in detection technology are needed to comply with the requirements in the Clean Air Act of 1990, Title 3, which requires the monitoring of air toxics. Fourier transform infrared (FTIR) spectroscopy can satisfy these requirements in two different modes. Conventional FTIR spectrometers can be installed on-stream so that a vapor stream enters an infrared cell for analysis. Other types of FTIR spectrometers can detect chemical plumes remotely, measure the natural emissions of the molecules in the plume. The samples do not come to the instrument, and the instrument has neither source nor reflector mirrors. We will discuss the applications of FTIR spectrometry for both conventional and passive-remote FTIR spectroscopy. Some applications of conventional FTIR include a continuous emission monitor for measuring incinerator emissions and determining indoor air quality. Passive-remote FTIR spectroscopy can be used to identify and track a chemical plume. It can also be used to detect fugitive emissions. Hence, it can be used as an independent means to assure compliance with environmental regulations in real-time. Because of the relatively simple instrumentation, passive-remote instruments can be helicopter- or vehicle-mounted for mobile detection of plumes.

  11. Fourier Transform Infrared spectrum of the OCD bending mode in methanol-D1

    NASA Astrophysics Data System (ADS)

    Mukhopadhyay, Indra

    2016-03-01

    The infrared (IR) spectra corresponding to OCD bending vibration of asymmetrically deuterated methanol species CH2DOH have been recorded with a Fourier Transform Spectrometer. The spectrum shows a typical structure of a parallel a-type band. This is expected because the bending vibration mainly executed parallel to the symmetry axis The Q-branch lines are grouped closely around 896 cm-1 and the P- and R-Branches show complex structure. Nonetheless it was possible to assign a-type P- and R-branch lines up to K value of 8 and J value up to about 20 in most cases. The Q-branch lines for higher K values can be followed to about J = 15, the presence of which confirmed the assignments. The observations suggest that in the OCD bend some energy levels are highly interacted by highly excited torsional state from the ground torsional state. A full catalogue is presented along with the effective molecular parameters. An intensity anomaly was also observed in the transitions. So far it has been possible to assign only transitions between e0 ← e0 states. Plausible explanations of intensity anomaly are presented. Lastly, a number of optically pumped far infrared (FIR) laser lines have been assigned either to exact or tentative quantum states. These assignments should prove valuable for production of new FIR laser lines.

  12. Study on dietary fibre by Fourier transform-infrared spectroscopy and chemometric methods.

    PubMed

    Chylińska, Monika; Szymańska-Chargot, Monika; Kruk, Beata; Zdunek, Artur

    2016-04-01

    Fresh fruit is an important part of the diet of people all over the world as a significant source of water, vitamins and natural sugars. Nowadays it is also one of the main sources of dietary fibre. In fruit the dietary fibre is simply cell wall consisting essentially of polysaccharides. The aim of present study was to predict the contents of pectins, cellulose and hemicelluloses by partial least squares regression (PLS) analysis on the basis of Fourier transform-infrared (FT-IR) spectra of fruit cell wall residue. The second purpose was to analyse the composition of dietary fibre from fruit based on FT-IR spectral information in combination with chemometric methods (principle components analysis (PCA) and hierarchical cluster analysis (HCA)). Additionally the contents of polysaccharides in studied fruits were determined by analytical methods. It has been shown that the analysis of infrared spectra and the use of multivariate statistical methods can be useful for studying the composition of dietary fibre. PMID:26593472

  13. Fourier transform infrared spectroscopy studies of water-polymer interactions in chemically amplified photoresists

    SciTech Connect

    McDonough, Laurie A.; Chikan, Viktor; Kim, Zee Hwan; Leone, Stephen R.; Hinsberg, William D.

    2004-12-08

    Fourier-Transform Infrared (FTIR) absorption spectroscopy is implemented to measure the infrared spectrum of water absorbed by the Poly(t-butoxycarbonylstyrene) (tBOC) and the ketal-protected Poly(hydroxystyrene) (KRS-XE) polymer photoresists. The shape and intensity of the OH stretching band of the water spectrum is monitored in a variety of humidity conditions in order to obtain information on the hydrogen-bonding interactions between the water and the polymer chains. The band is deconvoluted into four sub-bands, which represent four types of water molecules in different environments. Because of the hydrophilicity of the polymers studied, a large portion of the sorbed water molecules is believed to be strongly bound to the polar sites of the polymer. The ratios of each type of water are found to be dependent on the humidity conditions to which the sample was exposed. At higher humidities, there is an increase in the fraction of free and weakly-bound water molecules. These findings are used to explain the humidity dependence of the deprotection reaction rates, since certain types of water may slow transport of reactive species within the polymer network.

  14. Characteristics of electrically injured skin from human hand tissue samples using Fourier transform infrared microspectroscopy.

    PubMed

    Li, Shi-Ying; Zou, Dong-Hua; Luo, Yi-Wen; Sun, Qi-Ran; Deng, Kai-Fei; Chen, Yi-Jiu; Huang, Ping

    2014-01-01

    This technical note describes a method for distinguishing normal skin tissue samples from those electrically injured by Fourier transform infrared microspectroscopy (FTIR MSP). Furthermore, the infrared spectral features of electrically injured cells and tissues were evaluated to identify molecular changes in epidermal cells. In the present study, 20 human hand tissue samples were evaluated macroscopically and histopathologically. The electrically injured skin samples were subdivided into 2 regions [normal cell regions (NCRs) and polarized cell regions (PCRs)] and 14 major spectral absorption bands were selected. The spectral results showed that the band absorbance at 1080, 1126, 1172, 1242, 1307, 1403, 1456, 1541, 2852, 2925, 2957, 3075, and 3300cm(-1) increased significantly both in the stratum and non-stratum corneum of the PCRs in electrically injured skin tissues samples. No significant difference was found between normal skin and the NCR of the electrically injured skin samples. The band absorbance ratios of A1172/A1126, A1456/A1403, and A2925/A2957 were significantly increased, whereas the A1652/A1541 ratio was decreased in the PCR of the stratum corneum and non-stratum corneum. Baseline changes from 4000 to near 1737cm(-1) were observed in the spectra of the electrically injured skin samples, which were interpreted in terms of the pathological process involved in electrical injury. FTIR-MSP presents a useful method to provide objective spectral markers for the assisted diagnosis of electrical marks.

  15. Representation and transformation of Langley's map of the infrared solar spectrum

    NASA Astrophysics Data System (ADS)

    Loettgers, Andrea

    In 1900, after 18 years of research, the American astrophysicist Samuel Pierpont Langley published the final report of his investigations in the infrared region of the solar spectrum. (See Samuel P. Langley: Annals of the Astrophysical Observatory of the Smithsonian Institution, Vol. 1, Washington: Goverment Printing Office, 1900.) In this report one finds three different types of maps of the infrared region, extending from 1.1 mu-m to 5.3 mu-m and showing the positions of 750 absorption lines: a bolograph, a line spectrum and a normal spectrum. (The bolograph, the line spectrum and the normal spectrum are accessible as pl. XX and XXIV at http://adsbit.harvard.edu/books/saoann/.) Looking at these three distinct forms of representation raises the questions: Why did Langley decide to use three representations for the visualization of his results? How are these distinct representations connected? An analysis of the first question will provide further insight into the ``connection between instruments, practices, and the visual'', into the recording, evaluation and processing of the data and, furthermore, into the historical and disciplinary contexts. The prevailing trend toward the automation of measuring and registration processes, and the associated claim of `mechanical objectivity', together with standards concerning precision and completeness set by Henry Rowland's photographic measurements in the visible part of the spectrum, turn out to be the strongest elements in the development of the different forms of representation and their respective transformations.

  16. Fourier transform infrared spectroscopic imaging of cardiac tissue to detect collagen deposition after myocardial infarction

    NASA Astrophysics Data System (ADS)

    Cheheltani, Rabee; Rosano, Jenna M.; Wang, Bin; Sabri, Abdel Karim; Pleshko, Nancy; Kiani, Mohammad F.

    2012-05-01

    Myocardial infarction often leads to an increase in deposition of fibrillar collagen. Detection and characterization of this cardiac fibrosis is of great interest to investigators and clinicians. Motivated by the significant limitations of conventional staining techniques to visualize collagen deposition in cardiac tissue sections, we have developed a Fourier transform infrared imaging spectroscopy (FT-IRIS) methodology for collagen assessment. The infrared absorbance band centered at 1338 cm-1, which arises from collagen amino acid side chain vibrations, was used to map collagen deposition across heart tissue sections of a rat model of myocardial infarction, and was compared to conventional staining techniques. Comparison of the size of the collagen scar in heart tissue sections as measured with this methodology and that of trichrome staining showed a strong correlation (R=0.93). A Pearson correlation model between local intensity values in FT-IRIS and immuno-histochemical staining of collagen type I also showed a strong correlation (R=0.86). We demonstrate that FT-IRIS methodology can be utilized to visualize cardiac collagen deposition. In addition, given that vibrational spectroscopic data on proteins reflect molecular features, it also has the potential to provide additional information about the molecular structure of cardiac extracellular matrix proteins and their alterations.

  17. Enzymatic transesterification monitored by an easy-to-use Fourier transform infrared spectroscopy method.

    PubMed

    Natalello, Antonino; Sasso, Francesco; Secundo, Francesco

    2013-01-01

    Transesterification of triglycerides with short chain alcohols is the key reaction in biodiesel production, in addition to other applications in chemical synthesis. However, it is crucial to optimize reaction conditions to make enzymatic transesterification a cost-effective and competitive process. In this work, a new, easy Fourier transform infrared (FTIR) spectroscopic approach for monitoring the transesterification reaction is reported and compared with a gas-chromatographic method. The concentration of the total methyl esters in the reaction mixture is determined from the peak intensity at ∼1435 cm(-1) in the second derivatives of the FTIR absorption spectra using a linear regression calibration. Interestingly, we found that the use of second derivatives allows an accurate determination of the methyl esters without the interference of free fatty acids. Moreover, information on substrate hydrolysis can be obtained within the same measurement by the infrared absorption at ∼1709 cm(-1) . We applied this approach to monitor methanolysis and hydrolysis reactions catalyzed by different commercial lipases, which displayed different sensitivities to methanol inhibition. Therefore, the FTIR approach reported in this work represents a rapid, inexpensive, and accurate method to monitor enzymatic transesterification, requiring very limited sample preparation and a simple statistical analysis of the spectroscopic data.

  18. Application of Fourier transform infrared spectroscopy to studies of aqueous protein solutions.

    PubMed

    Zuber, G; Prestrelski, S J; Benedek, K

    1992-11-15

    Modern protein Fourier transform infrared (FT-IR) spectroscopy has proven to be a versatile and sensitive technique, applicable to many aspects of protein characterization. The major practical drawback for the FT-IR spectroscopy of proteins is the large absorbance band of water, which overlaps the amide I resonances. D2O is often substituted for H2O in infrared experiments. Removal of water from protein samples can be complicated and tedious and potentially lead to denaturation, aggregation, or sample loss. Solvent removal by dialysis is difficult for suspensions and sols. A new method called the D2O dilution technique (Ddt) is described which simplifies the sample preparation step and improves the solvent subtraction. The effect of the D2O concentration on the IR spectrum of aqueous solutions of several model proteins was studied. Dilution of aqueous samples with D2O yields good quality spectra. The Ddt has been evaluated for quantitative analysis using standard proteins and its applicability to solutions and suspensions of a genetically engineered malaria antigen is demonstrated. Use of resolution-enhancement techniques with spectra in mixed solvents has also been investigated. PMID:1489088

  19. Discrimination of healthy and osteoarthritic articular cartilage by Fourier transform infrared imaging and Fisher's discriminant analysis.

    PubMed

    Mao, Zhi-Hua; Yin, Jian-Hua; Zhang, Xue-Xi; Wang, Xiao; Xia, Yang

    2016-02-01

    Fourier transform infrared spectroscopic imaging (FTIRI) technique can be used to obtain the quantitative information of content and spatial distribution of principal components in cartilage by combining with chemometrics methods. In this study, FTIRI combining with principal component analysis (PCA) and Fisher's discriminant analysis (FDA) was applied to identify the healthy and osteoarthritic (OA) articular cartilage samples. Ten 10-μm thick sections of canine cartilages were imaged at 6.25μm/pixel in FTIRI. The infrared spectra extracted from the FTIR images were imported into SPSS software for PCA and FDA. Based on the PCA result of 2 principal components, the healthy and OA cartilage samples were effectively discriminated by the FDA with high accuracy of 94% for the initial samples (training set) and cross validation, as well as 86.67% for the prediction group. The study showed that cartilage degeneration became gradually weak with the increase of the depth. FTIRI combined with chemometrics may become an effective method for distinguishing healthy and OA cartilages in future. PMID:26977354

  20. The study of a single BGC823 cell using Fourier transform infrared microspectroscopic imaging

    NASA Astrophysics Data System (ADS)

    Wang, Xin; Qi, Zeming; Wang, Shengyi; Liu, Gang; Gao, Helong; Tian, Yangchao

    2011-09-01

    In order to investigate gastric cancer at cellular and sub-cellular level, a single human gastric adenocarcinoma BGC823 cell was studied by an infrared microscope equipped with a focal plane array (FPA) detector. The spectra showed difference between the nucleus and the endoplasmic reticulum (ER) of the BGC823 cell. The peak of v asPO 2- was shifted to a higher wavenumber at the nucleus compared with that at the ER. The height ratios of 2954 cm -1/2922 cm -1 (CH 3/CH 2) and 1088 cm -1/1539 cm -1 (DNA/amide II) of the nucleus were significantly higher than those of the ER. Furthermore, chemical images reveal the intensity distributions of lipids, proteins and DNA of the single BGC823 cell, and the intense absorptions of proteins and DNA were observed in the nuclear region of the cell while the intense absorption of lipids was found in the ER region of the cell. The Fourier transform infrared (FTIR) microspectroscopic imaging result indicates the study of the single gastric cancer cell at sub-cellular level can be beneficial for knowing gastric cancer more which will be of great importance for the study and diagnosis of gastric cancer. The result also suggests that FPA is a useful tool in the study of a single cell and may be a powerful tool for study and diagnosis of gastric cancer.

  1. Various new applications of fiber optic infrared Fourier transform spectroscopy for dermatology

    NASA Astrophysics Data System (ADS)

    Bruch, Reinhard F.; Afanasyeva, Natalia I.; Sukuta, Sydney; Brooks, Angelique L.; Makhine, Volodymyr; Kolyakov, Sergei F.

    1999-02-01

    Fiberoptical evanescent wave Fourier transform infrared (FEW- FTIR) spectroscopy has been applied in the middle infrared (MIR) wavelength range (3 to 20 micrometer) to the in vivo diagnostics of normal skin tissue, acupuncture points as well as precancerous and cancerous conditions. The FTIR-FEW technique, using nontoxic unclad fibers, is suitable for noninvasive, sensitive investigations of skin tissue for various dermatological studies of skin caner, aging, laser treatment, cosmetics, skin allergies, etc. This method is direct, nondestructive, and fast (seconds). Our optical fibers are nonhygroscopic, flexible, and characterized by extremely low losses. In this study, we have noninvasively investigated more than 300 cases of normal skin, acupuncture points, precancerous and cancerous tissue in the range of 1400 to 1800 cm-1. The results of our analysis of skin and other tissue are discussed in terms of structural and mathematical similarities and differences on a molecular level. In addition, we have also performed cluster analysis, using principal component scores, to confirm pathological classifications and to discriminate between genders. We have found good agreement with prior pathological classifications for normal skin tissue and melanoma tumors and normal females were distinctly separate from males.

  2. Fourier transform infrared difference and time-resolved infrared detection of the electron and proton transfer dynamics in photosynthetic water oxidation.

    PubMed

    Noguchi, Takumi

    2015-01-01

    Photosynthetic water oxidation, which provides the electrons necessary for CO₂ reduction and releases O₂ and protons, is performed at the Mn₄CaO₅ cluster in photosystem II (PSII). In this review, studies that assessed the mechanism of water oxidation using infrared spectroscopy are summarized focusing on electron and proton transfer dynamics. Structural changes in proteins and water molecules between intermediates known as Si states (i=0-3) were detected using flash-induced Fourier transform infrared (FTIR) difference spectroscopy. Electron flow in PSII and proton release from substrate water were monitored using the infrared changes in ferricyanide as an exogenous electron acceptor and Mes buffer as a proton acceptor. Time-resolved infrared (TRIR) spectroscopy provided information on the dynamics of proton-coupled electron transfer during the S-state transitions. In particular, a drastic proton movement during the lag phase (~200μs) before electron transfer in the S3→S0 transition was detected directly by monitoring the infrared absorption of a polarizable proton in a hydrogen bond network. Furthermore, the proton release pathways in the PSII proteins were analyzed by FTIR difference measurements in combination with site-directed mutagenesis, isotopic substitutions, and quantum chemical calculations. Therefore, infrared spectroscopy is a powerful tool for understanding the molecular mechanism of photosynthetic water oxidation. This article is part of a Special Issue entitled: Vibrational spectroscopies and bioenergetic systems.

  3. Chemometric analysis of attenuated total reflectance infrared spectra of Proteus mirabilis strains with defined structures of LPS.

    PubMed

    Zarnowiec, Paulina; Mizera, Andrzej; Chrapek, Magdalena; Urbaniak, Mariusz; Kaca, Wieslaw

    2016-07-01

    Proteus spp. strains are some of the most important pathogens associated with complicated urinary tract infections and bacteremia affecting patients with immunodeficiency and long-term urinary catheterization. For epidemiological purposes, various molecular typing methods have been developed for this pathogen. However, these methods are labor intensive and time consuming. We evaluated a new method of differentiation between strains. A collection of Proteus spp. strains was analyzed by attenuated total reflectance Fourier transform infrared (ATR FT-IR) spectroscopy in the mid-infrared region. ATR FT-IR spectroscopy used in conjunction with a diamond ATR accessory directly produced the biochemical profile of the surface chemistry of bacteria. We conclude that a combination of ATR FT-IR spectroscopy and mathematical modeling provides a fast and reliable alternative for discrimination between Proteus isolates, contributing to epidemiological research. PMID:27189426

  4. [Fast determination of induction period of motor gasoline using Fourier transform attenuated total reflection infrared spectroscopy].

    PubMed

    Liu, Ya-Fei; Yuan, Hong-Fu; Song, Chun-Feng; Xie, Jin-Chun; Li, Xiao-Yu; Yan, De-Lin

    2014-11-01

    A new method is proposed for the fast determination of the induction period of gasoline using Fourier transform attenuated total reflection infrared spectroscopy (ATR-FTIR). A dedicated analysis system with the function of spectral measurement, data processing, display and storage was designed and integrated using a Fourier transform infrared spectrometer module and chemometric software. The sample presentation accessory designed which has advantages of constant optical path, convenient sample injection and cleaning is composed of a nine times reflection attenuated total reflectance (ATR) crystal of zinc selenide (ZnSe) coated with a diamond film and a stainless steel lid with sealing device. The influence of spectral scanning number and repeated sample loading times on the spectral signal-to-noise ratio was studied. The optimum spectral scanning number is 15 times and the optimum sample loading number is 4 times. Sixty four different gasoline samples were collected from the Beijing-Tianjin area and the induction period values were determined as reference data by standard method GB/T 8018-87. The infrared spectra of these samples were collected in the operating condition mentioned above using the dedicated fast analysis system. Spectra were pretreated using mean centering and 1st derivative to reduce the influence of spectral noise and baseline shift A PLS calibration model for the induction period was established by correlating the known induction period values of the samples with their spectra. The correlation coefficient (R2), standard error of calibration (SEC) and standard error of prediction (SEP) of the model are 0.897, 68.3 and 91.9 minutes, respectively. The relative deviation of the model for gasoline induction period prediction is less than 5%, which meets the requirements of repeatability tolerance in GB method. The new method is simple and fast. It takes no more than 3 minutes to detect one sample. Therefore, the method is feasible for implementing

  5. Practical protocols for fast histopathology by Fourier transform infrared spectroscopic imaging

    NASA Astrophysics Data System (ADS)

    Keith, Frances N.; Reddy, Rohith K.; Bhargava, Rohit

    2008-02-01

    Fourier transform infrared (FT-IR) spectroscopic imaging is an emerging technique that combines the molecular selectivity of spectroscopy with the spatial specificity of optical microscopy. We demonstrate a new concept in obtaining high fidelity data using commercial array detectors coupled to a microscope and Michelson interferometer. Next, we apply the developed technique to rapidly provide automated histopathologic information for breast cancer. Traditionally, disease diagnoses are based on optical examinations of stained tissue and involve a skilled recognition of morphological patterns of specific cell types (histopathology). Consequently, histopathologic determinations are a time consuming, subjective process with innate intra- and inter-operator variability. Utilizing endogenous molecular contrast inherent in vibrational spectra, specially designed tissue microarrays and pattern recognition of specific biochemical features, we report an integrated algorithm for automated classifications. The developed protocol is objective, statistically significant and, being compatible with current tissue processing procedures, holds potential for routine clinical diagnoses. We first demonstrate that the classification of tissue type (histology) can be accomplished in a manner that is robust and rigorous. Since data quality and classifier performance are linked, we quantify the relationship through our analysis model. Last, we demonstrate the application of the minimum noise fraction (MNF) transform to improve tissue segmentation.

  6. A prototype stationary Fourier transform spectrometer for near-infrared absorption spectroscopy.

    PubMed

    Li, Jinyang; Lu, Dan-feng; Qi, Zhi-mei

    2015-09-01

    A prototype stationary Fourier transform spectrometer (FTS) was constructed with a fiber-coupled lithium niobate (LiNbO3) waveguide Mach-Zehnder interferometer (MZI) for the purpose of rapid on-site spectroscopy of biological and chemical measurands. The MZI contains push-pull electrodes for electro-optic modulation, and its interferogram as a plot of intensity against voltage was obtained by scanning the modulating voltage from -60 to +60 V in 50 ms. The power spectrum of input signal was retrieved by Fourier transform processing of the interferogram combined with the wavelength dispersion of half-wave voltage determined for the MZI used. The prototype FTS operates in the single-mode wavelength range from 1200 to 1700 nm and allows for reproducible spectroscopy. A linear concentration dependence of the absorbance at λmax = 1451 nm for water in ethanolic solution was obtained using the prototype FTS. The near-infrared spectroscopy of solid samples was also implemented, and the different spectra obtained with different materials evidenced the chemical recognition capability of the prototype FTS. To make this prototype FTS practically applicable, work on improving its spectral resolution by increasing the maximum optical path length difference is in progress.

  7. In situ CF3 Detection in Low Pressure Inductive Discharges by Fourier Transform Infrared Spectroscopy

    NASA Technical Reports Server (NTRS)

    Kim, J. S.; Cappelli, M. A.; Sharma, S. P.; Arnold, J. O. (Technical Monitor)

    1998-01-01

    The detection of CF(x) (x=1-3) radicals in low pressure discharges using source gases such as CF4 and CHF3 is of importance to the understanding of their chemical structure and relevance in plasma based etching processes. These radicals are known to contribute to the formation of fluorocarbon polymer films, which affect the selectivity and anisotropy of etching. In this study, we present preliminary results of the quantitative measurement of trifluoromethyl radicals, CF3, in low pressure discharges. The discharge studied here is an inductively (transformer) coupled plasma (ICP) source in the GEC reference cell, operating on pure CF4 at pressures ranging from 10 - 100 mTorr, This plasma source generates higher electron number densities at lower operating pressures than obtainable with the parallel-plate capacitively coupled version of the GEC reference cell. Also, this expanded operating regime is more relevant to new generations of industrial plasma reactors being used by the microelectronics industry. Fourier transform infrared (FTIR) spectroscopy is employed to observe the absorption band of CF3 radicals in the electronic ground state X2Al in the region of 1233-1270/cm. The spectrometer is equipped with a high sensitivity HgCdTe (MCT) detector and has a fixed resolution of 0.125/cm. The CF3 concentrations are measured for a range of operating pressures and discharge power levels.

  8. Preliminary evidence of oxidation in standard oven drying of cotton: attenuated total reflectance/ Fourier transform spectroscopy, colorimetry, and particulate matter formation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Moisture is paramount to cotton fiber properties dictating harvesting, ginning, storage and spinning as well as others. Currently, oven drying in air is often utilized to generate the percentage of moisture in cotton fibers. Karl Fischer Titration another method for cotton moisture, has been compa...

  9. PLANE-INTEGRATED OPEN-PATH FOURIER TRANSFORM INFRARED SPECTROMETRY METHODOLOGY FOR ANAEROBIC SWINE LAGOON EMISSION MEASUREMENTS

    EPA Science Inventory

    Emissions of ammonia and methane from an anaerobic lagoon at a swine animal feeding operation were evaluated five times over a period of two years. The plane-integrated (PI) open-path Fourier transform infrared spectrometry (OP-FTIR) methodology was used to transect the plume at ...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  11. Determination of Carbon Dioxide, Carbon Monoxide, and Methane Concentrations in Cigarette Smoke by Fourier Transform Infrared Spectroscopy

    ERIC Educational Resources Information Center

    Tan, T. L.; Lebron, G. B.

    2012-01-01

    The integrated absorbance areas of vibrational bands of CO[subscript 2], CO, and CH[subscript 4] gases in cigarette smoke were measured from Fourier transform infrared (FTIR) spectra to derive the partial pressures of these gases at different smoke times. The quantity of the three gas-phase components of cigarette smoke at different smoke times…

  12. CHARACTERIZATION OF AMBIENT PM2.5 AEROSOL AT A SOUTHEASTERN US SITE: FOURIER TRANSFORM INFRARED ANALYSIS OR PARTICLE PHASE

    EPA Science Inventory

    During a field study in the summer of 2000 in the Research Triangle Park (RTP), aerosol samples were collected using a five stage cascade impactor and subsequently analyzed using Fourier Transform Infrared Spectroscopy (FTIR). The impaction surfaces were stainless steel disks....

  13. [Evaluation of nutrient release profiles from polymer coated fertilizers using Fourier transform mid-infrared photoacoustic spectroscopy].

    PubMed

    Shen, Ya-zhen; Du, Chang-wen; Zhou, Jian-min; Wang, Huo-yan; Chen, Xiao-qin

    2012-02-01

    The acrylate-like materials were used to develop the polymer coated controlled release fertilizer, the nutrients release profiles were determined, meanwhile the Fourier transform mid-infrared photoacoustic spectra of the coatings were recorded and characterized; GRNN model was used to predict the nutrients release profiles using the principal components of the mid-infrared photoacoustic spectra as input. Results showed that the GRNN model could fast and effectively predict the nutrient release profiles, and the predicted calibration coefficients were more than 0.93; on the whole, the prediction errors (RMSE) were influenced by the profiling depth of the spectra, the average prediction error was 10.28%, and the spectra from the surface depth resulted in a lowest prediction error with 7.14%. Therefore, coupled with GRNN modeling, Fourier transform mid-infrared photoacoustic spectroscopy can be used as an alternative new technique in the fast and accurate prediction of nutrient release from polymer coated fertilizer. PMID:22512162

  14. [Evaluation of nutrient release profiles from polymer coated fertilizers using Fourier transform mid-infrared photoacoustic spectroscopy].

    PubMed

    Shen, Ya-zhen; Du, Chang-wen; Zhou, Jian-min; Wang, Huo-yan; Chen, Xiao-qin

    2012-02-01

    The acrylate-like materials were used to develop the polymer coated controlled release fertilizer, the nutrients release profiles were determined, meanwhile the Fourier transform mid-infrared photoacoustic spectra of the coatings were recorded and characterized; GRNN model was used to predict the nutrients release profiles using the principal components of the mid-infrared photoacoustic spectra as input. Results showed that the GRNN model could fast and effectively predict the nutrient release profiles, and the predicted calibration coefficients were more than 0.93; on the whole, the prediction errors (RMSE) were influenced by the profiling depth of the spectra, the average prediction error was 10.28%, and the spectra from the surface depth resulted in a lowest prediction error with 7.14%. Therefore, coupled with GRNN modeling, Fourier transform mid-infrared photoacoustic spectroscopy can be used as an alternative new technique in the fast and accurate prediction of nutrient release from polymer coated fertilizer.

  15. [Passive detection of aeroengine exhaust based on Fourier transform infrared system].

    PubMed

    Li, Shao-cheng; Zuo, Hong-fu; Xia, Qing

    2008-10-01

    Since the composition and concentration of aeroengine exhaust can reflect the combustion efficiency, they can provide the basis for condition based maintenance, and also the basis for the analysis of environment pollution caused by aeroengine exhaust. So the importance of aeroengine exhaust detection is evident. Up to now, the measurement of aeroengine exhaust is based on sampling analysis which is not convenient and can't meet the detection requirements when an aeroplane is flying-off or flying in the sky. Hence, new methods of exhaust detection must be studied. The passive measurement technology based on Fourier transform infrared spectroscopy (FTIR) was applied to the measurement of aeroengine exhaust in the present paper. At first, the principle of passive measurement based on FTIR was introduced in detail. On this basis, a model algorithm for gas concentration calculation was deduced based on the principle of infrared transmission. Then the feasibility of aeroengine exhaust measurement based on passive FTIR was analyzed, and the passive measurement method of aeroengine exhaust based on FTIR was given. In the end, an experiment of aeroengine exhaust passive measurement was carried out by a FTIR with the type of Tensor 27 produced by BRUKER. Good quality spectra of the exhaust and the background were measured. Based on the model algo rithm of passive measurement, the absorbance spectra of CO and NO were obtained respectively, and the concentrations of CO and NO were figured out. To check up the veracity of this method, a comparison was made with another apparatus. There were only little differences between the results of the two experiments, showing that the passive measurement technology based on FTIR could meet the requirements of aeroengine exhaust detection.

  16. Detection of exposure damage in composite materials using Fourier transform infrared technology.

    SciTech Connect

    Roach, Dennis Patrick; Duvall, Randy L.

    2010-09-01

    Goal: to detect the subtle changes in laminate composite structures brought about by thermal, chemical, ultraviolet, and moisture exposure. Compare sensitivity of an array of NDI methods, including Fourier Transform Infrared Spectroscopy (FTIR), to detect subtle differences in composite materials due to deterioration. Inspection methods applied: ultrasonic pulse echo, through transmission ultrasonics, thermography, resonance testing, mechanical impedance analysis, eddy current, low frequency bond testing & FTIR. Comparisons between the NDI methods are being used to establish the potential of FTIR to provide the necessary sensitivity to non-visible, yet significant, damage in the resin and fiber matrix of composite structures. Comparison of NDI results with short beam shear tests are being used to relate NDI sensitivity to reduction in structural performance. Chemical analyses technique, which measures the infrared intensity versus wavelength of light reflected on the surface of a structure (chemical and physical information via this signature). Advances in instrumentation have resulted in hand-held portable devices that allow for field use (few seconds per scan). Shows promise for production quality assurance and in-service applications on composite aircraft structures (scarfed repairs). Statistical analysis on frequency spectrums produced by FTIR interrogations are being used to produce an NDI technique for assessing material integrity. Conclusions are: (1) Use of NDI to assess loss of composite laminate integrity brought about by thermal, chemical, ultraviolet, and moisture exposure. (2) Degradation trends between SBS strength and exposure levels (temperature and time) have been established for different materials. (3) Various NDI methods have been applied to evaluate damage and relate this to loss of integrity - PE UT shows greatest sensitivity. (4) FTIR shows promise for damage detection and calibration to predict structural integrity (short beam shear). (5

  17. An evaluation of IASI-NH3 with ground-based Fourier transform infrared spectroscopy measurements

    NASA Astrophysics Data System (ADS)

    Dammers, Enrico; Palm, Mathias; Van Damme, Martin; Vigouroux, Corinne; Smale, Dan; Conway, Stephanie; Toon, Geoffrey C.; Jones, Nicholas; Nussbaumer, Eric; Warneke, Thorsten; Petri, Christof; Clarisse, Lieven; Clerbaux, Cathy; Hermans, Christian; Lutsch, Erik; Strong, Kim; Hannigan, James W.; Nakajima, Hideaki; Morino, Isamu; Herrera, Beatriz; Stremme, Wolfgang; Grutter, Michel; Schaap, Martijn; Wichink Kruit, Roy J.; Notholt, Justus; Coheur, Pierre-F.; Erisman, Jan Willem

    2016-08-01

    Global distributions of atmospheric ammonia (NH3) measured with satellite instruments such as the Infrared Atmospheric Sounding Interferometer (IASI) contain valuable information on NH3 concentrations and variability in regions not yet covered by ground-based instruments. Due to their large spatial coverage and (bi-)daily overpasses, the satellite observations have the potential to increase our knowledge of the distribution of NH3 emissions and associated seasonal cycles. However the observations remain poorly validated, with only a handful of available studies often using only surface measurements without any vertical information. In this study, we present the first validation of the IASI-NH3 product using ground-based Fourier transform infrared spectroscopy (FTIR) observations. Using a recently developed consistent retrieval strategy, NH3 concentration profiles have been retrieved using observations from nine Network for the Detection of Atmospheric Composition Change (NDACC) stations around the world between 2008 and 2015. We demonstrate the importance of strict spatio-temporal collocation criteria for the comparison. Large differences in the regression results are observed for changing intervals of spatial criteria, mostly due to terrain characteristics and the short lifetime of NH3 in the atmosphere. The seasonal variations of both datasets are consistent for most sites. Correlations are found to be high at sites in areas with considerable NH3 levels, whereas correlations are lower at sites with low atmospheric NH3 levels close to the detection limit of the IASI instrument. A combination of the observations from all sites (Nobs = 547) give a mean relative difference of -32.4 ± (56.3) %, a correlation r of 0.8 with a slope of 0.73. These results give an improved estimate of the IASI-NH3 product performance compared to the previous upper-bound estimates (-50 to +100 %).

  18. Long open path Fourier transform spectroscopy measurements of greenhouse gases in the near infrared

    NASA Astrophysics Data System (ADS)

    Griffith, David; Pöhler, Denis; Schmidt, Stefan; Hammer, Samuel; Vardag, Sanam; Levin, Ingeborg; Platt, Ulrich

    2015-04-01

    Atmospheric composition measurements are an important tool to quantify local and regional emissions and sinks of greenhouse gases. But how representative are in situ measurements at one point in an inhomogeneous environment? Open path Fourier Transform Spectroscopy (FTS) measurements potentially offer spatial averaging and continuous measurements of several trace gases (including CO2, CH4, CO and N2O) simultaneously in the same airmass. Spatial averaging over kilometre scales is a better fit to the finest scale atmospheric models becoming available, and helps bridge the gap between models and in situ measurements. With what precision, accuracy and reliability can such measurements be made? Building on our pooled experience in ground-level open path Fourier transform spectroscopy and TCCON solar FTS in the infrared (Wollongong) and long path DOAS techniques in the UV-visible (Heidelberg), we set up a new type of open path measurement system across a 1.5 km one-way path in urban Heidelberg, Germany, using FTS in the near infrared. Direct open-atmosphere measurements of trace gases CO2, CH4, CO and N2O as well as O2 were retrieved from several absorption bands between 4000 and 8000 cm-1 (2.5 - 1.25 micron). At one end of the path an in situ FTIR analyser simultaneously collected well calibrated measurements of the same species for comparison with the open path-integrated measurements. The measurements ran continuously from June - November 2014. We introduce the open path FTS measurement system and present an analysis of the results, including assessment of precision, accuracy relative to co-incident in situ measurements, reliability, and avenues for further improvements and extensions. Short term precision of the open path measurement of CO2 was better than 1 ppm for 5 minute averages and thus sufficient for studies in urban and other non-background environments. Measurement bias relative to calibrated in situ measurements was stable across the measurement period. The

  19. Fourier-Transform Raman and Fourier-Transform Infrared Spectroscopy (An Investigation of Five Higher Plant Cell Walls and Their Components).

    PubMed Central

    Sene, CFB.; McCann, M. C.; Wilson, R. H.; Grinter, R.

    1994-01-01

    Infrared and Raman spectra of sequentially extracted primary cell walls and their pectic polymers were obtained from five angiosperm plants. Fourier-transform Raman spectrometry was shown to be a powerful tool for the investigation of primary cell-wall architecture at a molecular level, providing complementary information to that obtained by Fourier-transform infrared microspectroscopy. The use of an extraction procedure using imidazole instead of cyclohexane trans-1,2-N,N,N[prime],N[prime]-diaminotetraacetate allows the extension of the infrared spectral window for data interpretation from 1300 to 800 cm-1, to 2000 to 800 cm-1, and allows us to obtain Raman spectra from extracted cell-wall material. Wall constituents such as pectins, proteins, aromatic phenolics, cellulose, and hemicellulose have characteristic spectral features that can be used to identify and/or fingerprint these polymers without, in most cases, the need for any physical separation. The Gramineae (rice [Oryza sativa], polypogon [Polypogon fugax steud], and sweet corn [Zea mays]) are spectroscopically very different from the nongraminaceous monocotyledon (onion [Allium cepa]) and the dicotyledon (carrot [Daucus carota]); this reflects differences in chemical composition and cross-linking of the walls. The possibility of a taxonomic classification of plant cell walls based on infrared and Raman spectroscopies and the use of spectral fingerprinting for authentication and detection of adulteration of products rich in cell-wall materials are discussed. PMID:12232436

  20. A Fourier transform infrared spectroscopy analysis of carious dentin from transparent zone to normal zone.

    PubMed

    Liu, Y; Yao, X; Liu, Y W; Wang, Y

    2014-01-01

    It is well known that caries invasion leads to the differentiation of dentin into zones with altered composition, collagen integrity and mineral identity. However, understanding of these changes from the fundamental perspective of molecular structure has been lacking so far. In light of this, the present work aims to utilize Fourier transform infrared spectroscopy (FTIR) to directly extract molecular information regarding collagen's and hydroxyapatite's structural changes as dentin transitions from the transparent zone (TZ) into the normal zone (NZ). Unembedded ultrathin dentin films were sectioned from carious teeth, and an FTIR imaging system was used to obtain spatially resolved FTIR spectra. According to the mineral-to-matrix ratio image generated from large-area low-spectral-resolution scan, the TZ, the NZ and the intermediate subtransparent zone (STZ) were identified. High-spectral-resolution spectra were taken from each zone and subsequently examined with regard to mineral content, carbonate distribution, collagen denaturation and carbonate substitution patterns. The integrity of collagen's triple helical structure was also evaluated based on spectra collected from demineralized dentin films of selected teeth. The results support the argument that STZ is the real sclerotic layer, and they corroborate the established knowledge that collagen in TZ is hardly altered and therefore should be reserved for reparative purposes. Moreover, the close resemblance between the STZ and the NZ in terms of carbonate content, and that between the STZ and the TZ in terms of being A-type carbonate-rich, suggest that the mineral that initially occludes dentin tubules is hydroxyapatite newly generated from odontoblastic activities, which is then transformed into whitlockite in the demineralization/remineralization process as caries progresses.

  1. A Fourier Transform Infrared Spectroscopy Analysis of Carious Dentin from Transparent Zone to Normal Zone

    PubMed Central

    Liu, Y.; Yao, X.; Liu, Y.W.; Wang, Y.

    2015-01-01

    It is well known that caries invasion leads to the differentiation of dentin into zones with altered composition, collagen integrity and mineral identity. However, understanding of these changes from the fundamental perspective of molecular structure has been lacking so far. In light of this, the present work aims to utilize Fourier transform infrared spectroscopy (FTIR) to directly extract molecular information regarding collagen's and hydroxyapatite's structural changes as dentin transitions from the transparent zone (TZ) into the normal zone (NZ). Unembedded ultrathin dentin films were sectioned from carious teeth, and an FTIR imaging system was used to obtain spatially resolved FTIR spectra. According to the mineral-to-matrix ratio image generated from large-area low-spectral-resolution scan, the TZ, the NZ and the intermediate subtransparent zone (STZ) were identified. High-spectral-resolution spectra were taken from each zone and subsequently examined with regard to mineral content, carbonate distribution, collagen denaturation and carbonate substitution patterns. The integrity of collagen's triple helical structure was also evaluated based on spectra collected from demineralized dentin films of selected teeth. The results support the argument that STZ is the real sclerotic layer, and they corroborate the established knowledge that collagen in TZ is hardly altered and therefore should be reserved for reparative purposes. Moreover, the close resemblance between the STZ and the NZ in terms of carbonate content, and that between the STZ and the TZ in terms of being A-type carbonate-rich, suggest that the mineral that initially occludes dentin tubules is hydroxyapatite newly generated from odontoblastic activities, which is then transformed into whitlockite in the demineralization/remineralization process as caries progresses. PMID:24556607

  2. Rapid analysis of two food-borne microbial communities at the species level by Fourier-transform infrared microspectroscopy.

    PubMed

    Wenning, Mareike; Theilmann, Vera; Scherer, Siegfried

    2006-05-01

    The species composition of microbial communities in natural habitats may be extremely complex and therefore a quantitative analysis of the fraction each species contributes to the consortium has proven to be difficult. During recent years, the identification of bacterial pure cultures based on their infrared spectra has been established. Fourier-transform infrared microspectroscopy now proceeds a step further and allows identification of microorganisms directly plated from community dilutions. Infrared spectra of microcolonies of 70-250 microm in diameter can be recorded without producing a pure culture of the isolate. We have applied this novel technique for quantitative comparative analysis of two undefined, geographically separated food-borne smear cheese microbial consortia of limited complexity. Due to the high degree of automation, up to 200 microcolonies could be identified in 1 day and, in total, 3170 infrared spectra of microcolonies were recorded. The results obtained have been verified by Fourier-transform infrared macrospectroscopy and 16S rDNA sequencing. Interestingly, although the communities were unrelated, Staphylococcus equorum, Corynebacterium casei, Arthrobacter casei and Brevibacterium linens were found to be part of both consortia, however, with different incidence. In addition, Corynebacterium variabile, Microbacterium gubbeenense, Brachybacterium alimentarium, Enterococcus faecalis and an unknown species were detected in either one of the consortia.

  3. Identification of Yersinia ruckeri from diseased salmonid fish by Fourier transform infrared spectroscopy.

    PubMed

    Wortberg, F; Nardy, E; Contzen, M; Rau, J

    2012-01-01

    Yersinia ruckeri is the causative agent of enteric redmouth disease (ERM), which mainly affects salmonid fish. Isolates of Y. ruckeri from diseased salmonid fish were obtained over a 6-year period from eight fish farms in the State of Baden-Württemberg, Southwest Germany. The strains were characterized by biochemical methods and Fourier transform infrared spectroscopy (FT-IR) combined with artificial neural network analysis. These methods were complemented by 16S rDNA sequencing for several isolates. The set of strains from these fish farms included sorbitol-positive, gelatinase-positive and non-motile Y. ruckeri. These variants were differentiated with an advanced FT-IR module, which is part of a higher-ranking method including more than 200 well-defined Yersinia strains against a background of more than 1000 other Gram-negative isolates. Validation of the newly constructed method yielded 97.4% of Y. ruckeri identified correctly on the species level. Thus, the FT-IR analysis enables distinction of all Y. ruckeri from other Yersinia species (e.g. fish-borne Y. enterocolitica) and other Enterobacteriaceae typically misidentified because of similar biochemical reaction profiles, especially Hafnia alvei. The differentiation of sorbitol-positive variants of Y. ruckeri using FT-IR was demonstrated.

  4. Analysis of the DNA Fourier transform-infrared microspectroscopic signature using an all-reflecting objective.

    PubMed

    Mello, Maria Luiza S; Vidal, Benedicto C

    2014-06-01

    The Fourier transform-infrared (FT-IR) signature of dry samples of DNA and DNA-polypeptide complexes, as studied by IR microspectroscopy using a diamond attenuated total reflection (ATR) objective, has revealed important discriminatory characteristics relative to the PO2(-) vibrational stretchings. However, DNA IR marks that provide information on the sample's richness in hydrogen bonds have not been resolved in the spectral profiles obtained with this objective. Here we investigated the performance of an "all reflecting objective" (ARO) for analysis of the FT-IR signal of hydrogen bonds in DNA samples differing in base richness types (salmon testis vs calf thymus). The results obtained using the ARO indicate prominent band peaks at the spectral region representative of the vibration of nitrogenous base hydrogen bonds and of NH and NH2 groups. The band areas at this spectral region differ in agreement with the DNA base richness type when using the ARO. A peak assigned to adenine was more evident in the AT-rich salmon DNA using either the ARO or the ATR objective. It is concluded that, for the discrimination of DNA IR hydrogen bond vibrations associated with varying base type proportions, the use of an ARO is recommended.

  5. Effect of spectral resolution on pattern recognition analysis using passive fourier transform infrared sensor data

    SciTech Connect

    Bangalore, Arjun S.; Demirgian, Jack C.; Boparai, Amrit S.; Small, Gary W.

    1999-11-01

    The Fourier transform infrared (FT-IR) spectral data of two nerve agent simulants, diisopropyl methyl phosphonate (DIMP) and dimethyl methyl phosphonate (DMMP), are used as test cases to determine the spectral resolution that gives optimal pattern recognition performance. DIMP is used as the target analyte for detection, while DMMP is used to test the ability of the automated pattern recognition methodology to detect the analyte selectively. Interferogram data are collected by using a Midac passive FT-IR instrument. The methodology is based on the application of pattern recognition techniques to short segments of single-beam spectra obtained by Fourier processing the collected interferogram data. The work described in this article evaluates the effect of varying spectral resolution on the pattern recognition results. The objective is to determine the optimal spectral resolution to be used for data collection. The results of this study indicate that the data with a nominal spectral resolution of 16 cm{sup -1} provide sufficient selectivity to give pattern recognition results comparable to that obtained by using higher resolution data. We found that, while higher resolution does not increase selectivity sufficiently to provide better pattern recognition results, lower resolution decreases selectivity and degrades the pattern recognition results. These results can be used as guidelines to maximize detection sensitivity, to minimize the time needed for data collection, and to reduce data storage requirements. (c) 2000 Society for Applied Spectroscopy.

  6. Study of the hydrolysis of uranium hexafluoride by Fourier transform infrared spectroscopy

    SciTech Connect

    Anderson, S.P.

    1982-08-01

    The reaction of uranium hexafluoride with water has been studied by using Fourier transform infrared (FT-IR) spectroscopy. Several different methods for accomplishing this task have been carried out. In addition, interpretatins of the results have been made. These interpretations have been based on literature values for the reactants and for compounds analogous to possible products. It was shown that classical matrix-isolation techniques proved to be unsatisfactory for studying this reaction. Other methods were developed in order to obtain results. They were: (1) the codeposition of pure UF/sub 6/ and H/sub 2/O on a cold window at 16/sup 0/K, (2) the codeposition of argon matrix to sample ratios of 10:1 to 2:1 of UF/sub 6/ and H/sub 2/O at 16/sup 0/K, and (3) the annealing of the samples produced by (1) and (2) while they were being scanned with FT-IR. 78 refs., 86 figs., 7 tabs.

  7. Chemometric evaluation of physicochemical properties of carbonated-apatitic preparations by Fourier transform infrared spectroscopy.

    PubMed

    Otsuka, Makoto; Papangkorn, Kongnara; Baig, Arif A; Higuchi, William I

    2012-08-01

    The purpose of this study was to develop a simple and quick method of evaluating the physicochemical properties of carbonated apatite preparations (CAP) as an index of the bioaffinity of implantable materials based on Fourier-transformed-infrared (IR) spectra by chemometrics. The wet-synthesized CAPs contained various levels of carbonate content (CO(3)), and were analyzed microstrain parameter (MS), crystallite size parameter (CP), specific surface area (Sw), CO(3), and solubility parameter (pK(HAP)) using by X-ray powder diffraction, nitrogen gas adsorption, IR, and UV absorption. The IR spectral results of CAPs suggested that the peak intensities of CAP reflected the physicochemical properties of the samples. The IR data sets were calculated to obtain calibration models evaluating the physicochemical properties of CAPs by a partial least squares regression analysis (PLS). As validation of the calibration model, physicochemical properties of CAP could be evaluated based on validation IR data sets of independent samples, and those values had sufficient accuracy. The regression vector of each calibration model suggested that the physicochemical properties of CAP, such as CO(3), Sw, MS, CP, and pK(HAP), were affected by phosphate, hydroxyl, and carbonate groups.

  8. Spectroscopic analysis of bladder cancer tissues using Fourier transform infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Al-Muslet, Nafie A.; Ali, Essam E.

    2012-03-01

    Bladder cancer is one of the most common cancers in Africa. It takes several days to reach a diagnosis using histological examinations of specimens obtained by endoscope, which increases the medical expense. Recently, spectroscopic analysis of bladder cancer tissues has received considerable attention as a diagnosis technique due to its sensitivity to biochemical variations in the samples. This study investigated the use of Fourier transform infrared (FTIR) spectroscopy to analyze a number of bladder cancer tissues. Twenty-two samples were collected from 11 patients diagnosed with bladder cancer from different hospitals without any pretreatment. From each patient two samples were collected, one normal and another cancerous. FTIR spectrometer was used to differentiate between normal and cancerous bladder tissues via changes in spectra of these samples. The investigations detected obvious changes in the bands of proteins (1650, 1550 cm-1), lipids (2925, 2850 cm-1), and nucleic acid (1080, 1236 cm-1). The results show that FTIR spectroscopy is promising as a rapid, accurate, nondestructive, and easy to use alternative method for identification and diagnosis of bladder cancer tissues.

  9. Applications of Micro-Fourier Transform Infrared Spectroscopy (FTIR) in the Geological Sciences--A Review.

    PubMed

    Chen, Yanyan; Zou, Caineng; Mastalerz, Maria; Hu, Suyun; Gasaway, Carley; Tao, Xiaowan

    2015-12-18

    Fourier transform infrared spectroscopy (FTIR) can provide crucial information on the molecular structure of organic and inorganic components and has been used extensively for chemical characterization of geological samples in the past few decades. In this paper, recent applications of FTIR in the geological sciences are reviewed. Particularly, its use in the characterization of geochemistry and thermal maturation of organic matter in coal and shale is addressed. These investigations demonstrate that the employment of high-resolution micro-FTIR imaging enables visualization and mapping of the distributions of organic matter and minerals on a micrometer scale in geological samples, and promotes an advanced understanding of heterogeneity of organic rich coal and shale. Additionally, micro-FTIR is particularly suitable for in situ, non-destructive characterization of minute microfossils, small fluid and melt inclusions within crystals, and volatiles in glasses and minerals. This technique can also assist in the chemotaxonomic classification of macrofossils such as plant fossils. These features, barely accessible with other analytical techniques, may provide fundamental information on paleoclimate, depositional environment, and the evolution of geological (e.g., volcanic and magmatic) systems.

  10. Spectroscopic signature of mouse embryonic stem cell-derived hepatocytes using synchrotron Fourier transform infrared microspectroscopy

    NASA Astrophysics Data System (ADS)

    Thumanu, Kanjana; Tanthanuch, Waraporn; Ye, Danna; Sangmalee, Anawat; Lorthongpanich, Chanchao; Parnpai, Rangsun; Heraud, Philip

    2011-05-01

    Stem cell-based therapy for liver regeneration has been proposed to overcome the persistent shortage in the supply of suitable donor organs. A requirement for this to succeed is to find a rapid method to detect functional hepatocytes, differentiated from embryonic stem cells. We propose Fourier transform infrared (FTIR) microspectroscopy as a versatile method to identify the early and last stages of the differentiation process leading to the formation of hepatocytes. Using synchrotron-FTIR microspectroscopy, the means of identifying hepatocytes at the single-cell level is possible and explored. Principal component analysis and subsequent partial least-squares (PLS) discriminant analysis is applied to distinguish endoderm induction from hepatic progenitor cells and matured hepatocyte-like cells. The data are well modeled by PLS with endoderm induction, hepatic progenitor cells, and mature hepatocyte-like cells able to be discriminated with very high sensitivity and specificity. This method provides a practical tool to monitor endoderm induction and has the potential to be applied for quality control of cell differentiation leading to hepatocyte formation.

  11. Fourier transform infrared analysis of Tamra Bhasma at different levels: A preliminary study

    PubMed Central

    Chaudhari, Swapnil Y.; Rajput, Dhirajsingh S.; Galib, R.; Prajapati, Pradeep Kumar

    2015-01-01

    Introduction: Tamra Bhasma, one among the herbo-metallic preparations is extensively used in Ayurveda for different conditions. To make it safe to use, Tamra has to pass through a set of classical pharmaceutical procedures including a series of quenching in prescribed liquids, followed by incineration with black sulfide of mercury and herbal juice of Citrus jambhiri Lush. and corm of Amorphophallus campanulatus Linn. FTIR profiles of Tamra Bhasma at different levels is not available. Aim: To evaluate the chemical changes in Tamra Bhasma at different steps by following Fourier transform infrared (FTIR) spectroscopy. Materials and Methods: In current study, raw Tamra, intermediate samples obtained during purification, incineration and Amritikarana were analyzed using FTIR. Results: It was observed that Shodhana procedure leads in the formation of bonds between surface particles of Tamra and Shodhana media. These formed bonds on the surface of Shodhita Tamra samples gave various sharp peaks representing presence of many functional groups. Conclusion: The FTIR spectra revealed that both Bhasma samples contained organic compounds probably in the form of a complex with common functional groups like alkyl, methyl, etc., which need further studies for exact characterization of the complexes. PMID:26730144

  12. Multivariate Calibration and Model Integrity for Wood Chemistry Using Fourier Transform Infrared Spectroscopy

    PubMed Central

    Zhou, Chengfeng; Jiang, Wei; Cheng, Qingzheng; Via, Brian K.

    2015-01-01

    This research addressed a rapid method to monitor hardwood chemical composition by applying Fourier transform infrared (FT-IR) spectroscopy, with particular interest in model performance for interpretation and prediction. Partial least squares (PLS) and principal components regression (PCR) were chosen as the primary models for comparison. Standard laboratory chemistry methods were employed on a mixed genus/species hardwood sample set to collect the original data. PLS was found to provide better predictive capability while PCR exhibited a more precise estimate of loading peaks and suggests that PCR is better for model interpretation of key underlying functional groups. Specifically, when PCR was utilized, an error in peak loading of ±15 cm−1 from the true mean was quantified. Application of the first derivative appeared to assist in improving both PCR and PLS loading precision. Research results identified the wavenumbers important in the prediction of extractives, lignin, cellulose, and hemicellulose and further demonstrated the utility in FT-IR for rapid monitoring of wood chemistry. PMID:26576321

  13. Fourier transform infrared microspectroscopy is a new way to look at plant cell walls.

    PubMed

    McCann, M C; Hammouri, M; Wilson, R; Belton, P; Roberts, K

    1992-12-01

    Highly reproducible Fourier transform infrared (FTIR) spectra from both single onion (Allium cepa) cell walls and their constituent polymers were obtained under a variety of sampling conditions. The specificity of the chemical extraction sequence used in the preparation of the material was confirmed: pectins only are extracted by cyclohexanediaminetetraacetic acid and sodium carbonate, whereas xyloglucans are extracted by increasing concentrations of potassium hydroxide. There was very little contamination of the first potassium hydroxide extract with residual pectin. The low abundance of both phenolics and protein was also confirmed. The first sodium carbonate extraction almost completely removes esters remaining in the cell wall. We have demonstrated that FTIR spectroscopy can detect large conformational changes in pectic polymers on removal from the cell wall and on drying. FTIR spectroscopy provides a powerful and rapid assay for wall components and putative cross-links by identifying polymers and functional groups nondestructively in muro. The availability of micro-sampling and data acquisition techniques that permit subtraction of the blanket absorption of water make FTIR spectroscopy particularly suitable for studies of cell wall architecture. The use of polarizers with the microscope accessory permits determination of the orientation of particular functional groups with respect to the direction of cell elongation in carrot suspension cells.

  14. Structural effects of simvastatin on liver rate tissue: Fourier transform infrared and Raman microspectroscopic studies

    NASA Astrophysics Data System (ADS)

    Garip, Sebnem; Bayari, Sevgi Haman; Severcan, Mete; Abbas, Sherif; Lednev, Igor K.; Severcan, Feride

    2016-02-01

    Simvastatin is one of the most frequently prescribed statins because of its efficacy in the treatment of hypercholesterolemia, reducing cardiovascular risk and related mortality. Determination of its side effects on different tissues is mandatory to improve safe use of this drug. In the present study, the effects of simvastatin on molecular composition and structure of healthy rat livers were investigated by Fourier transform infrared and Raman imaging. Simvastatin-treated groups received 50 mg/kg/day simvastatin for 30 days. The ratio of the area and/or intensity of the bands assigned to lipids, proteins, and nucleic acids were calculated to get information about the drug-induced changes in tissues. Loss of unsaturation, accumulation of end products of lipid peroxidation, and alterations in lipid-to-protein ratio were observed in the treated group. Protein secondary structure studies revealed significant decrease in α-helix and increase in random coil, while native β-sheet decreases and aggregated β-sheet increases in treated group implying simvastatin-induced protein denaturation. Moreover, groups were successfully discriminated using principal component analysis. Consequently, high-dose simvastatin treatment induces hepatic lipid peroxidation and changes in molecular content and protein secondary structure, implying the risk of liver disorders in drug therapy.

  15. High-Throughput Metabolic Fingerprinting of Legume Silage Fermentations via Fourier Transform Infrared Spectroscopy and Chemometrics

    PubMed Central

    Johnson, Helen E.; Broadhurst, David; Kell, Douglas B.; Theodorou, Michael K.; Merry, Roger J.; Griffith, Gareth W.

    2004-01-01

    Silage quality is typically assessed by the measurement of several individual parameters, including pH, lactic acid, acetic acid, bacterial numbers, and protein content. The objective of this study was to use a holistic metabolic fingerprinting approach, combining a high-throughput microtiter plate-based fermentation system with Fourier transform infrared (FT-IR) spectroscopy, to obtain a snapshot of the sample metabolome (typically low-molecular-weight compounds) at a given time. The aim was to study the dynamics of red clover or grass silage fermentations in response to various inoculants incorporating lactic acid bacteria (LAB). The hyperspectral multivariate datasets generated by FT-IR spectroscopy are difficult to interpret visually, so chemometrics methods were used to deconvolute the data. Two-phase principal component-discriminant function analysis allowed discrimination between herbage types and different LAB inoculants and modeling of fermentation dynamics over time. Further analysis of FT-IR spectra by the use of genetic algorithms to identify the underlying biochemical differences between treatments revealed that the amide I and amide II regions (wavenumbers of 1,550 to 1,750 cm−1) of the spectra were most frequently selected (reflecting changes in proteins and free amino acids) in comparisons between control and inoculant-treated fermentations. This corresponds to the known importance of rapid fermentation for the efficient conservation of forage proteins. PMID:15006782

  16. Fourier transform infrared spectroscopy of DNA from Borrelia burgdorferi sensu lato and Ixodes ricinus ticks

    NASA Astrophysics Data System (ADS)

    Muntean, Cristina M.; Stefan, Razvan; Bindea, Maria; Cozma, Vasile

    2013-06-01

    In this work we present a method for detection of motile and immotile Borrelia burgdorferi genomic DNA, in relation with infectious and noninfectious spirochetes. An FT-IR study of DNA isolated from B. burgdorferi sensu lato strains and from positive and negative Ixodes ricinus ticks, respectively, is reported. Motile bacterial cells from the species B. burgdorferi sensu stricto, Borrelia garinii and Borrelia afzelii were of interest. Also, FT-IR absorbance spectra of DNA from immotile spirochetes of B. burgdorferi sensu stricto, in the absence and presence of different antibiotics (doxycycline, erythromycin, gentamicin, penicillin V or phenoxymethylpenicillin, tetracycline, respectively) were investigated. FT-IR spectra, providing a high molecular structural information, have been analyzed in the wavenumber range 400-1800 cm-1. FT-IR signatures, spectroscopic band assignments and structural interpretations of these DNAs are reported. Spectral differences between FT-IR absorbances of DNAs from motile bacterial cells and immotile spirochetes, respectively, have been found. Particularly, alterations of the sugar-phosphate B-form chain in the case of DNA from Borrelia immotile cells, as compared with DNA from B. burgdorferi sensu lato motile cells have been observed. Based on this work, specific B. burgdorferi sensu lato and I. ricinus DNA-ligand interactions, respectively, might be further investigated using Fourier transform infrared spectroscopy.

  17. [Rapid identification of microorganisms based on Fourier transform near infrared spectroscopy].

    PubMed

    Yue, Tian-li; Wang, Jun; Yuan, Ya-hong; Gao, Zhen-peng

    2010-11-01

    Fourier transform-near infrared (FT-NIR) spectra of microorganisms reflect the overall molecular composition of the sample. The spectra were specific and can serve as spectroscopic fingerprints that enable highly accurate identification of microorganisms. Bacterial powders of one yeast and five bacteria strains were prepared to collect FT-NIR spectra. FT-NIR measurements were done using a diffuse reflection-integrating sphere. Reduction of data was performed by principal component analysis (PCA) and two identification models based on linear discriminant analysis (LDA) and artificial neural network (ANN) were established to identify bacterial strains. The reproducibility of the method was proved to be excellent (D(yly2) : 1.61 +/- 1.05-10.97 +/- 6. 65) and high identification accuracy was achieved in both the LDA model (Accuracy rate: 100%) and the ANN model (Average relative error: 5.75%). FT-NIR spectroscopy combined with multivariate statistical analysis (MSA) may provide a novel answer to the fields which need for rapid microbial identification and it will have great prospect in industry.

  18. Classification of select category A and B bacteria by Fourier transform infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Samuels, Alan C.; Snyder, A. Peter; St. Amant, Diane; Emge, Darren K.; Minter, Jennifer; Campbell, Mark; Tripathi, Ashish

    2008-04-01

    Relatively few reports have investigated the determination and classification of pathogens such as the National Institute of Allergy and Infectious Diseases (NIAID) Category A Bacillus anthracis spores and cells (BA), Yersinia species, Francisella tularensis (FT), and Category B Brucella species from FTIR spectra. We investigated the classification ability of the Fourier transform infrared (FTIR) spectra of viable pathogenic and non-pathogenic NIAID Category A and B bacteria. The impact of different growth media, growth time and temperature, rolling circle filter of the data, and wavelength range were investigated for their microorganism differentiation. Various 2-D PC plots provided differential degrees of separation with respect to the four viable, bacterial genera including the BA sub-categories of pathogenic spores, vegetative cells, and nonpathogenic vegetative cells. FT spectra were separated from that of the three other genera. The BA pathogenic spore strains 1029, LA1, and Ames were clearly differentiated from the rest of the dataset. Yersinia species were distinctly separated from the remaining dataset and could also be classified by growth media. This work provided evidence that FTIR spectroscopy can separate the four major pathogenic bacterial genera of NIAID Category A and B biological threat agents.

  19. Renal Graft Fibrosis and Inflammation Quantification by an Automated Fourier-Transform Infrared Imaging Technique.

    PubMed

    Vuiblet, Vincent; Fere, Michael; Gobinet, Cyril; Birembaut, Philippe; Piot, Olivier; Rieu, Philippe

    2016-08-01

    Renal interstitial fibrosis and interstitial active inflammation are the main histologic features of renal allograft biopsy specimens. Fibrosis is currently assessed by semiquantitative subjective analysis, and color image analysis has been developed to improve the reliability and repeatability of this evaluation. However, these techniques fail to distinguish fibrosis from constitutive collagen or active inflammation. We developed an automatic, reproducible Fourier-transform infrared (FTIR) imaging-based technique for simultaneous quantification of fibrosis and inflammation in renal allograft biopsy specimens. We generated and validated a classification model using 49 renal biopsy specimens and subsequently tested the robustness of this classification algorithm on 166 renal grafts. Finally, we explored the clinical relevance of fibrosis quantification using FTIR imaging by comparing results with renal function at 3 months after transplantation (M3) and the variation of renal function between M3 and M12. We showed excellent robustness for fibrosis and inflammation classification, with >90% of renal biopsy specimens adequately classified by FTIR imaging. Finally, fibrosis quantification by FTIR imaging correlated with renal function at M3, and the variation in fibrosis between M3 and M12 correlated well with the variation in renal function over the same period. This study shows that FTIR-based analysis of renal graft biopsy specimens is a reproducible and reliable label-free technique for quantifying fibrosis and active inflammation. This technique seems to be more relevant than digital image analysis and promising for both research studies and routine clinical practice.

  20. Supercritical Fluid Chromatography/Fourier Transform Infrared Spectroscopy Of Food Components

    NASA Astrophysics Data System (ADS)

    Calvey, Elizabeth M.; Page, Samuel W.; Taylor, Larry T.

    1989-12-01

    Supercritical fluid (SF) technologies are being investigated extensively for applications in food processing. The number of SF-related patents issued testifies to the level of interest. Among the properties of materials at temperatures and pressures above their critical points (supercritical fluids) is density-dependent solvating power. Supercritical CO2 is of particular interest to the food industry because of its low critical temperature (31.3°C) and low toxicity. Many of the components in food matrices react or degrade at elevated temperatures and may be adversely affected by high temperature extractions. Likewise, these components may not be amenable to GC analyses. Our SF research has been in the development of methods employing supercritical fluid chromatography (SFC) and extraction (SFE) coupled to a Fourier transform infrared (FT-IR) spectrometer to investigate food composition. The effects of processing techniques on the isomeric fatty acid content of edible oils and the analysis of lipid oxidation products using SFC/FT-IR with a flow-cell interface are described.

  1. Applications of Micro-Fourier Transform Infrared Spectroscopy (FTIR) in the Geological Sciences—A Review

    PubMed Central

    Chen, Yanyan; Zou, Caineng; Mastalerz, Maria; Hu, Suyun; Gasaway, Carley; Tao, Xiaowan

    2015-01-01

    Fourier transform infrared spectroscopy (FTIR) can provide crucial information on the molecular structure of organic and inorganic components and has been used extensively for chemical characterization of geological samples in the past few decades. In this paper, recent applications of FTIR in the geological sciences are reviewed. Particularly, its use in the characterization of geochemistry and thermal maturation of organic matter in coal and shale is addressed. These investigations demonstrate that the employment of high-resolution micro-FTIR imaging enables visualization and mapping of the distributions of organic matter and minerals on a micrometer scale in geological samples, and promotes an advanced understanding of heterogeneity of organic rich coal and shale. Additionally, micro-FTIR is particularly suitable for in situ, non-destructive characterization of minute microfossils, small fluid and melt inclusions within crystals, and volatiles in glasses and minerals. This technique can also assist in the chemotaxonomic classification of macrofossils such as plant fossils. These features, barely accessible with other analytical techniques, may provide fundamental information on paleoclimate, depositional environment, and the evolution of geological (e.g., volcanic and magmatic) systems. PMID:26694380

  2. Strain dependent UV degradation of Escherichia coli DNA monitored by Fourier transform infrared spectroscopy.

    PubMed

    Muntean, Cristina M; Lapusan, Alexandra; Mihaiu, Liora; Stefan, Razvan

    2014-01-01

    In this work we present a method for detection of DNA isolated from nonpathogenic Escherichia coli strains, respectively. Untreated and UV irradiated bacterial DNAs were analyzed by FT-IR spectroscopy, to investigate their screening characteristic features and their structural radiotolerance at 253.7nm. FT-IR spectra, providing a high molecular structural information, have been analyzed in the wavenumber range 800-1800cm(-1). FT-IR signatures, spectroscopic band assignments and structural interpretations of these DNAs are reported. Also, UV damage at the DNA molecular level is of interest. Strain dependent UV degradation of DNA from E. coli has been observed. Particularly, alterations in nucleic acid bases, base pairing and base stacking have been found. Also changes in the DNA conformation and deoxyribose were detected. Based on this work, specific E. coli DNA-ligand interactions, drug development and vaccine design for a better understanding of the infection mechanism caused by an interference between pathogenic and nonpathogenic bacteria and for a better control of disease, respectively, might be further investigated using Fourier transform infrared spectroscopy. Besides, understanding the pathways for UV damaged DNA response, like nucleic acids repair mechanisms is appreciated.

  3. Localization of polyhydroxybutyrate in sugarcane using Fourier-transform infrared microspectroscopy and multivariate imaging

    SciTech Connect

    Lupoi, Jason S.; Smith-Moritz, Andreia; Singh, Seema; McQualter, Richard; Scheller, Henrik V.; Simmons, Blake A.; Henry, Robert J.

    2015-07-10

    Background: Slow-degrading, fossil fuel-derived plastics can have deleterious effects on the environment, especially marine ecosystems. The production of bio-based, biodegradable plastics from or in plants can assist in supplanting those manufactured using fossil fuels. Polyhydroxybutyrate (PHB) is one such biodegradable polyester that has been evaluated as a possible candidate for relinquishing the use of environmentally harmful plastics. Results: PHB, possessing similar properties to polyesters produced from non-renewable sources, has been previously engineered in sugarcane, thereby creating a high-value co-product in addition to the high biomass yield. This manuscript illustrates the coupling of a Fourier-transform infrared microspectrometer, equipped with a focal plane array (FPA) detector, with multivariate imaging to successfully identify and localize PHB aggregates. Principal component analysis imaging facilitated the mining of the abundant quantity of spectral data acquired using the FPA for distinct PHB vibrational modes. PHB was measured in the chloroplasts of mesophyll and bundle sheath cells, acquiescent with previously evaluated plant samples. Conclusion: This study demonstrates the power of IR microspectroscopy to rapidly image plant sections to provide a snapshot of the chemical composition of the cell. While PHB was localized in sugarcane, this method is readily transferable to other value-added co-products in different plants.

  4. Localization of polyhydroxybutyrate in sugarcane using Fourier-transform infrared microspectroscopy and multivariate imaging

    DOE PAGESBeta

    Lupoi, Jason S.; Smith-Moritz, Andreia; Singh, Seema; McQualter, Richard; Scheller, Henrik V.; Simmons, Blake A.; Henry, Robert J.

    2015-07-10

    Background: Slow-degrading, fossil fuel-derived plastics can have deleterious effects on the environment, especially marine ecosystems. The production of bio-based, biodegradable plastics from or in plants can assist in supplanting those manufactured using fossil fuels. Polyhydroxybutyrate (PHB) is one such biodegradable polyester that has been evaluated as a possible candidate for relinquishing the use of environmentally harmful plastics. Results: PHB, possessing similar properties to polyesters produced from non-renewable sources, has been previously engineered in sugarcane, thereby creating a high-value co-product in addition to the high biomass yield. This manuscript illustrates the coupling of a Fourier-transform infrared microspectrometer, equipped with a focalmore » plane array (FPA) detector, with multivariate imaging to successfully identify and localize PHB aggregates. Principal component analysis imaging facilitated the mining of the abundant quantity of spectral data acquired using the FPA for distinct PHB vibrational modes. PHB was measured in the chloroplasts of mesophyll and bundle sheath cells, acquiescent with previously evaluated plant samples. Conclusion: This study demonstrates the power of IR microspectroscopy to rapidly image plant sections to provide a snapshot of the chemical composition of the cell. While PHB was localized in sugarcane, this method is readily transferable to other value-added co-products in different plants.« less

  5. Fourier transform infrared study of the effect of different cations on bacteriorhodopsin protein thermal stability.

    PubMed Central

    Heyes, Colin D; Wang, Jianping; Sanii, Laurie S; El-Sayed, Mostafa A

    2002-01-01

    The effect of divalent ion binding to deionized bacteriorhodopsin (dI-bR) on the thermal transitions of the protein secondary structure have been studied by using temperature-dependent Fourier transform infrared (FT-IR) spectroscopy. The native metal ions in bR, Ca(2+), and Mg(2+), which we studied previously, are compared with Mn(2+), Hg(2+), and a large, synthesized divalent organic cation, ((Et)(3)N)(2)Bu(2+). It was found that in all cases of ion regeneration, there is a pre-melting, reversible conformational transition in which the amide frequency shifts from 1665 to 1652 cm(-1). This always occurs at approximately 80 degrees C, independent of which cation is used for the regeneration. The irreversible thermal transition (melting), monitored by the appearance of the band at 1623 cm(-1), is found to occur at a lower temperature than that for the native bR but higher than that for acid blue bR in all cases. However, the temperature for this transition is dependent on the identity of the cation. Furthermore, it is shown that the mechanism of melting of the organic cation regenerated bR is different than for the metal cations, suggesting a difference in the type of binding to the protein (either to different sites or different binding to the same site). These results are used to propose specific direct binding mechanisms of the ions to the protein of deionized bR. PMID:11867472

  6. Attenuated total reflection (ATR) Fourier transform infrared spectroscopy of dimyristoyl phosphatidylserine-cholesterol mixtures.

    PubMed

    Bach, D; Miller, I R

    2001-10-01

    Mixtures of cholesterol with dimyristoyl phosphatidylserine or deuterated dimyristoyl phosphatidylserine were investigated by polarized and non polarized attenuated total reflection (ATR) Fourier transform infrared (FTIR) Spectroscopy. From polarized spectra the dichroic ratios of various vibrations as a function of cholesterol were calculated. Dichroic ratios of methylene vibration (CH(2)) 2934 cm(-1) of cholesterol decreases with increase of cholesterol concentration leveling off in the region where cholesterol phase separation takes place. The orientation of deuterated methylene (CD(2)) symmetric and asymmetric bands of the deuterated dimyristoyl phosphatidylserine is influenced little by cholesterol. In the polar region of dimyristoyl phosphatidylserine no effect of cholesterol on the dichroic ratios of carbonyl (C==O) and asymmetric phosphate (PO(2)(-)) vibrations were detected. For nonpolarized spectra the broad bands in the polar region of the phospholipid were deconvoluted. The carbonyl band (C==O) in pure dimyristoyl phosphatidylserine is composed of five bands; in the presence of increasing concentrations of cholesterol conformational change of these vibrations takes place evolving into one predominant band. Similar conformational change takes place in the presence of 75 molecules water/molecule DMPS. For the asymmetric phosphate band very small shifts due to interaction with cholesterol were detected.

  7. Stereochemistry of quinoxaline antagonist binding to a glutamate receptor investigated by Fourier transform infrared spectroscopy.

    PubMed

    Madden, D R; Thiran, S; Zimmermann, H; Romm, J; Jayaraman, V

    2001-10-12

    The stereochemistry of the interactions between quinoxaline antagonists and the ligand-binding domain of the glutamate receptor 4 (GluR4) have been investigated by probing their vibrational modes using Fourier transform infrared spectroscopy. In solution, the electron-withdrawing nitro groups of both compounds establish a resonance equilibrium that appears to stabilize the keto form of one of the cyclic amide carbonyl bonds. Changes in the 6,7-dinitro-2,3-dihydroxyquinoxaline vibrational spectra on binding to the glutamate receptor, interpreted within the framework of a published crystal structure, illuminate the stereochemistry of the interaction and suggest that the binding site imposes a more polarized electronic bonding configuration on this antagonist. Similar spectral changes are observed for 6-cyano-7-dinitro-2,3-dihydroxyquinoxaline, confirming that its interactions with the binding site are highly similar to those of 6,7-dinitro-2,3-dihydroxyquinoxaline and leading to a model of the 6-cyano-7-dinitro-2,3-dihydroxyquinoxaline-S1S2 complex, for which no crystal structure is available. Conformational changes within the GluR ligand binding domain were also monitored. Compared with the previously reported spectral changes seen on binding of the agonist glutamate, only a relatively small change is detected on antagonist binding. This correlation between the functional effects of different classes of ligand and the magnitude of the spectroscopic changes they induce suggests that the spectral data reflect physiologically relevant conformational processes.

  8. Renal Graft Fibrosis and Inflammation Quantification by an Automated Fourier-Transform Infrared Imaging Technique.

    PubMed

    Vuiblet, Vincent; Fere, Michael; Gobinet, Cyril; Birembaut, Philippe; Piot, Olivier; Rieu, Philippe

    2016-08-01

    Renal interstitial fibrosis and interstitial active inflammation are the main histologic features of renal allograft biopsy specimens. Fibrosis is currently assessed by semiquantitative subjective analysis, and color image analysis has been developed to improve the reliability and repeatability of this evaluation. However, these techniques fail to distinguish fibrosis from constitutive collagen or active inflammation. We developed an automatic, reproducible Fourier-transform infrared (FTIR) imaging-based technique for simultaneous quantification of fibrosis and inflammation in renal allograft biopsy specimens. We generated and validated a classification model using 49 renal biopsy specimens and subsequently tested the robustness of this classification algorithm on 166 renal grafts. Finally, we explored the clinical relevance of fibrosis quantification using FTIR imaging by comparing results with renal function at 3 months after transplantation (M3) and the variation of renal function between M3 and M12. We showed excellent robustness for fibrosis and inflammation classification, with >90% of renal biopsy specimens adequately classified by FTIR imaging. Finally, fibrosis quantification by FTIR imaging correlated with renal function at M3, and the variation in fibrosis between M3 and M12 correlated well with the variation in renal function over the same period. This study shows that FTIR-based analysis of renal graft biopsy specimens is a reproducible and reliable label-free technique for quantifying fibrosis and active inflammation. This technique seems to be more relevant than digital image analysis and promising for both research studies and routine clinical practice. PMID:26683669

  9. Detailed description of oil shale organic and mineralogical heterogeneity via fourier transform infrared mircoscopy

    USGS Publications Warehouse

    Washburn, Kathryn E.; Birdwell, Justin E.; Foster, Michael; Gutierrez, Fernando

    2015-01-01

    Mineralogical and geochemical information on reservoir and source rocks is necessary to assess and produce from petroleum systems. The standard methods in the petroleum industry for obtaining these properties are bulk measurements on homogenized, generally crushed, and pulverized rock samples and can take from hours to days to perform. New methods using Fourier transform infrared (FTIR) spectroscopy have been developed to more rapidly obtain information on mineralogy and geochemistry. However, these methods are also typically performed on bulk, homogenized samples. We present a new approach to rock sample characterization incorporating multivariate analysis and FTIR microscopy to provide non-destructive, spatially resolved mineralogy and geochemistry on whole rock samples. We are able to predict bulk mineralogy and organic carbon content within the same margin of error as standard characterization techniques, including X-ray diffraction (XRD) and total organic carbon (TOC) analysis. Validation of the method was performed using two oil shale samples from the Green River Formation in the Piceance Basin with differing sedimentary structures. One sample represents laminated Green River oil shales, and the other is representative of oil shale breccia. The FTIR microscopy results on the oil shales agree with XRD and LECO TOC data from the homogenized samples but also give additional detail regarding sample heterogeneity by providing information on the distribution of mineral phases and organic content. While measurements for this study were performed on oil shales, the method could also be applied to other geological samples, such as other mudrocks, complex carbonates, and soils.

  10. Applications of Micro-Fourier Transform Infrared Spectroscopy (FTIR) in the Geological Sciences—A Review

    DOE PAGESBeta

    Chen, Yanyan; Zou, Caineng; Mastalerz, Maria; Hu, Suyun; Gasaway, Carley; Tao, Xiaowan

    2015-12-18

    Fourier transform infrared spectroscopy (FTIR) can provide crucial information on the molecular structure of organic and inorganic components and has been used extensively for chemical characterization of geological samples in the past few decades. In this paper, recent applications of FTIR in the geological sciences are reviewed. Particularly, its use in the characterization of geochemistry and thermal maturation of organic matter in coal and shale is addressed. These investigations demonstrate that the employment of high-resolution micro-FTIR imaging enables visualization and mapping of the distributions of organic matter and minerals on a micrometer scale in geological samples, and promotes an advancedmore » understanding of heterogeneity of organic rich coal and shale. Additionally, micro-FTIR is particularly suitable for in situ, non-destructive characterization of minute microfossils, small fluid and melt inclusions within crystals, and volatiles in glasses and minerals. This technique can also assist in the chemotaxonomic classification of macrofossils such as plant fossils. These features, barely accessible with other analytical techniques, may provide fundamental information on paleoclimate, depositional environment, and the evolution of geological (e.g., volcanic and magmatic) systems.« less

  11. Applications of Micro-Fourier Transform Infrared Spectroscopy (FTIR) in the Geological Sciences—A Review

    SciTech Connect

    Chen, Yanyan; Zou, Caineng; Mastalerz, Maria; Hu, Suyun; Gasaway, Carley; Tao, Xiaowan

    2015-12-18

    Fourier transform infrared spectroscopy (FTIR) can provide crucial information on the molecular structure of organic and inorganic components and has been used extensively for chemical characterization of geological samples in the past few decades. In this paper, recent applications of FTIR in the geological sciences are reviewed. Particularly, its use in the characterization of geochemistry and thermal maturation of organic matter in coal and shale is addressed. These investigations demonstrate that the employment of high-resolution micro-FTIR imaging enables visualization and mapping of the distributions of organic matter and minerals on a micrometer scale in geological samples, and promotes an advanced understanding of heterogeneity of organic rich coal and shale. Additionally, micro-FTIR is particularly suitable for in situ, non-destructive characterization of minute microfossils, small fluid and melt inclusions within crystals, and volatiles in glasses and minerals. This technique can also assist in the chemotaxonomic classification of macrofossils such as plant fossils. These features, barely accessible with other analytical techniques, may provide fundamental information on paleoclimate, depositional environment, and the evolution of geological (e.g., volcanic and magmatic) systems.

  12. Comparative analysis of smokeless gunpowders by Fourier transform infrared and Raman spectroscopy.

    PubMed

    López-López, María; Ferrando, Jose Luis; García-Ruiz, Carmen

    2012-03-01

    Fourier Transform Infrared (FTIR) and Raman spectroscopic techniques were used to perform a comparative study of the spectral profiles of single-base, double-base and triple-base smokeless gunpowders. Preliminary results based on visual comparison of the spectra point out that spectra obtained by both vibrational techniques were useful for a rapid identification of gunpowders containing dinitrotoluene as one of the major components and triple-base gunpowders. Additionally, the Raman spectra of gunpowders with diphenylamine in its primary composition showed a characteristic band, assigned to 2-nitro-diphenylamine, allowing the identification of this type of gunpowders. Further differentiation among the spectra of different types of smokeless gunpowders obtained by both vibrational spectroscopic techniques was investigated by discriminant analysis. Different analyses were applied to spectral data considering the different composition of gunpowders. The presence or absence of different compounds (such as dinitrotoluene, diphenylamine or dibutyl phthalate) or the type of gunpowder according to the number of active components (single-base or double-base gunpowder) has been taken into account. FTIR and Raman spectroscopy in combination with discriminant analyses were successful tools of forensic interest for the classification of gunpowders and the possible identification of unknown samples of gunpowders.

  13. Quantitative analysis of hemoglobin content in polymeric nanoparticles as blood substitutes using Fourier transform infrared spectroscopy.

    PubMed

    Shan, Xiaoqian; Chen, Ligen; Yuan, Yuan; Liu, Changsheng; Zhang, Xiaolan; Sheng, Yan; Xu, Feng

    2010-01-01

    Based on the penetrability of IR within the polymeric nanoparticles, a novel Fourier transform infrared spectroscopy (FTIR) method, with polyacrylonitrile (PAN) as the internal reference standard, was developed to quantify the hemoglobin (Hb) content in Hb-based polymeric nanoparticles (HbPN). The HbPN was fabricated by double emulsion method from poly(ethylene glycol)-poly(lactic acid)-poly(ethylene glycol) triblock copolymers. Depending on the characteristic un-overlapped IR absorbances at 1540 cm(-1) of Hb (amide II) and at 2241 cm(-1) of PAN(-C[triple bond]N), calibration equations, presenting the peak height ratio of Hb and PAN as a function of the weight ratio of Hb and PAN, were established. This new quantification method is validated and used to the determination Hb content in HbPN. Due to the good results of this calibration strategy, the proposed simple FTIR approach with minimal sample-needed and solvent-free makes it useful for routine analysis of protein content and could be also applied to any other drug/protein encapsulated particles.

  14. Fourier transform infrared microspectroscopy is a new way to look at plant cell walls.

    PubMed

    McCann, M C; Hammouri, M; Wilson, R; Belton, P; Roberts, K

    1992-12-01

    Highly reproducible Fourier transform infrared (FTIR) spectra from both single onion (Allium cepa) cell walls and their constituent polymers were obtained under a variety of sampling conditions. The specificity of the chemical extraction sequence used in the preparation of the material was confirmed: pectins only are extracted by cyclohexanediaminetetraacetic acid and sodium carbonate, whereas xyloglucans are extracted by increasing concentrations of potassium hydroxide. There was very little contamination of the first potassium hydroxide extract with residual pectin. The low abundance of both phenolics and protein was also confirmed. The first sodium carbonate extraction almost completely removes esters remaining in the cell wall. We have demonstrated that FTIR spectroscopy can detect large conformational changes in pectic polymers on removal from the cell wall and on drying. FTIR spectroscopy provides a powerful and rapid assay for wall components and putative cross-links by identifying polymers and functional groups nondestructively in muro. The availability of micro-sampling and data acquisition techniques that permit subtraction of the blanket absorption of water make FTIR spectroscopy particularly suitable for studies of cell wall architecture. The use of polarizers with the microscope accessory permits determination of the orientation of particular functional groups with respect to the direction of cell elongation in carrot suspension cells. PMID:16653221

  15. Cation Occupancy Determination in Manganese Zinc Ferrites using Fourier Transform Infrared Spectroscopy

    SciTech Connect

    Shultz,M.; Carpenter, E.; Morrison, S.; Calvin, S.

    2006-01-01

    The magnetic and electric properties of ferrites are influenced by the cation distribution within the crystalline spinel lattice. Methods such as extended x-ray-absorption fine structure (EXAFS) have been used to determine cation occupancies within the crystalline structure of materials such as manganese zinc ferrite (MZFO); however, it is not practical to be used for daily analysis. Fourier transform infrared (FTIR) spectroscopy is another technique which has the potential to determine cation occupancy while offering speed and convenience. In the literature it has been demonstrated that in ferrite systems FTIR data can be correlated to cation percentages when comparing tetrahedral (Td) and octahedral (Oh) sites. FTIR spectra were collected on a series of MZFO nanoparticles in the range from 200 to 600 cm-1 and two absorbance peaks were observed. The first absorption region shifted with changing sample composition as calculated from transmission EXAFS experiments and elemental analysis. The data was normalized to the maximum of the peak of interest and the shifts were correlated to cation occupancy.

  16. Advances in passive-remote and extractive Fourier transform infrared spectroscopic systems

    SciTech Connect

    Demirgian, J.C.; Hammer, C.; Hwang, E.; Mao, Zhuoxiong

    1993-10-01

    The Clean Air Act of 1990 requires the monitoring of air toxics including those from incinerator emissions. Continuous emission monitors (CEM) would demonstrate the safety of incinerators and address public concern about emissions of hazardous organic compounds. Fourier transform infrared (FTIR) spectroscopy can provide the technology for continuous emission monitoring of stacks. Stack effluent can be extracted and analyzed in less than one minute with conventional FTIR spectrometers. Passive-remote FTIR spectrometers can detect certain emission gases over 1 km away from a stack. The authors discuss advances in both extractive and passive-remote FTIR technology. Extractive systems are being tested with EPA protocols, which will soon replace periodic testing methods. Standard operating procedures for extractive systems are being developed and tested. Passive-remote FTIR spectrometers have the advantage of not requiring an extracted sample; however, they have less sensitivity. We have evaluated the ability of commercially available systems to detect fugitive plumes and to monitor carbon monoxide at a coal-fired power plant.

  17. Advances in passive-remote and extractive Fourier transform infrared systems

    SciTech Connect

    Demirgian, J.C.; Hammer, C.; Hwang, E.; Zhuoxiong Mao

    1993-07-01

    The Clean Air Act of 1990 requires the monitoring of air toxics including those from incinerator emissions. Continuous emission monitors (CEM) would demonstrate the safety of incinerators and address public concern about emissions of hazardous organic compounds. Fourier transform infrared (FTIR) spectroscopy can provide the technology for continuous emission monitoring of stacks. Stack effluent can be extracted and analyzed in under one minute with conventional FTIR spectrometers. Passive-remote FTIR spectrometers can detect certain emission gases over 1 km away from a stack. The authors will discuss advances in both extractive and passive-remote FTIR technology. Extractive systems are being tested with EPA protocols, which will soon replace periodic testing methods. Standard operating procedures for extractive systems are being developed and tested. Passive-remote FTIR spectrometers have the advantage of not requiring an extracted sample; however, they have less sensitivity. The authors have evaluated the ability of commercially available systems to detect fugitive plumes and to monitor carbon monoxide at a coal-fired power plant.

  18. Detection of emission sources using passive-remote Fourier transform infrared spectroscopy

    SciTech Connect

    Demirgian, J.C.; Macha, S.M.; Darby, S.M.; Ditillo, J.

    1995-04-01

    The detection and identification of toxic chemicals released in the environment is important for public safety. Passive-remote Fourier transform infrared (FTIR) spectrometers can be used to detect these releases. Their primary advantages are their small size and ease of setup and use. Open-path FTIR spectrometers are used to detect concentrations of pollutants from a fixed frame of reference. These instruments detect plumes, but they are too large and difficult to aim to be used to track a plume to its source. Passive remote FTIR spectrometers contain an interferometer, optics, and a detector. They can be used on tripods and in some cases can be hand-held. A telescope can be added to most units. We will discuss the capability of passive-remote FTIR spectrometers to detect the origin of plumes. Low concentration plumes were released using a custom-constructed vaporizer. These plumes were detected with different spectrometers from different distances. Passive-remote spectrometers were able to detect small 10 cm on a side chemical releases at concentration-pathlengths at the low parts per million-meter (ppm-m) level.

  19. Fourier Transform Near Infrared Spectrometry: Using Interferograms To Determine Chemical Composition

    NASA Astrophysics Data System (ADS)

    Hoy, R. M.; McClure, W. Fred

    1989-12-01

    Previous research conducted in this laboratory has demonstrated several advantages accrued by transforming near infrared spectra from the wavelength domain to the Fourier domain. Those advantages include: [1] smoothing wavelength domain data without loss of end points, [2] correcting for particle size phenomena encountered in solid sample analyses by simply omitting the mean term Fourier coefficient from the "retransformation process", [3] minimizing the multicollinearity problem prevalent in wavelength space, [4] generating wavelength-space derivatives from Fourier space without loss of end points, [5] performing band enhancements via Fourier self-deconvolution, [6] identifying sample type using Fourier vectors, [7] estimating chemical composition using only the first few Fourier coefficients, [8] cutting of computer storage requirements by more than 96%, [9] cutting of calibration time by more than 96%, hence [10] reducing the drudgery of maintaining calibrations. That the first 12 Fourier coefficients contain sufficient information to determine chemical constituents in many products has turned out to be a major advantage leading us to understand that the chemical absorption information in the wavelength spectrum of a sample obtained with an interferometer was also present in the interferogram.

  20. Analysis of Resistant Starches in Rat Cecal Contents Using Fourier Transform Infrared Photoacoustic Spectroscopy

    SciTech Connect

    Anderson, Timothy J.; Ai, Yongfeng; Jones, Roger W.; Houk, Robert S.; Jane, Jay-lin; Zhao, Yinsheng; Birt, Diane F.; McClelland, John F.

    2013-01-29

    Fourier transform infrared photoacoustic spectroscopy (FTIR-PAS) qualitatively and quantitatively measured resistant starch (RS) in rat cecal contents. Fisher 344 rats were fed diets of 55% (w/w, dry basis) starch for 8 weeks. Cecal contents were collected from sacrificed rats. A corn starch control was compared against three RS diets. The RS diets were high-amylose corn starch (HA7), HA7 chemically modified with octenyl succinic anhydride, and stearic-acid-complexed HA7 starch. To calibrate the FTIR-PAS analysis, samples from each diet were analyzed using an enzymatic assay. A partial least-squares cross-validation plot generated from the enzymatic assay and FTIR-PAS spectral results for starch fit the ideal curve with a R2 of 0.997. A principal component analysis plot of components 1 and 2 showed that spectra from diets clustered significantly from each other. This study clearly showed that FTIR-PAS can accurately quantify starch content and identify the form of starch in complex matrices.

  1. [Fourier transform infrared spectral analysis on peanut (Arachis Hypogaea) plants under calcium deficiency stress].

    PubMed

    Gao, Li-Li; Wang, Sheng-Feng; Han, Ya; Liu, Zi-Fei; Huang, Jin-Sheng; Hilman; Liu, Rong-Le; Wang, Hong

    2014-11-01

    The objective of the present study was to reveal different tolerance of peanut plants to Ca deficiency by determining Ca uptake and Fourier transform infrared spectral (FTIR) differences of two peanut cultivars grown in nutrition solution. Peanut cultivars LH11 and YZ9102 were selected. Seedlings at the first leaf stage were cultivated for 28 days in nutrient solution with 0, 0.01 and 2.0 mmol x L(-1) Ca treatments, respectively. The results showed that under 0 and 0.01 mmol x L(-1) Ca supply, YZ9102 did not show Ca deficiency symptoms and the plant biomass did not change, whereas LH11 exhibited shoot-tip necrosis, smaller plant size, more lateral branches, and plant dry matter weights decreased significantly. YZ9102 had higher plant Ca concentration and Ca accumulation than LH11. Besides, for LH11, Ca was mainly accumulated in roots, while for YZ9102 mainly in leaves. As compared with plants cultivated in 2.0 mol x L(-1) Ca nutrition, root, stem and leaf of LH11 plants under Ca deficiency stress showed higher transmittance at peaks 1 060, 1 380, 1 655, 2 922, and 3 420 cm(-1) in FTIR spectra, indicating that the contents of protein, sugar and lipid decreased obviously in LH11 plants in condition that Ca supply was limited. However, the FTIR spectra of YZ9102 were less affected by Ca deficiency. It is suggested that YZ9102 might be more tolerant to Ca deficiency.

  2. Fourier Transform Infrared Microspectroscopy Is a New Way to Look at Plant Cell Walls

    PubMed Central

    McCann, Maureen C.; Hammouri, Mahmoud; Wilson, Reg; Belton, Peter; Roberts, Keith

    1992-01-01

    Highly reproducible Fourier transform infrared (FTIR) spectra from both single onion (Allium cepa) cell walls and their constituent polymers were obtained under a variety of sampling conditions. The specificity of the chemical extraction sequence used in the preparation of the material was confirmed: pectins only are extracted by cyclohexanediaminetetraacetic acid and sodium carbonate, whereas xyloglucans are extracted by increasing concentrations of potassium hydroxide. There was very little contamination of the first potassium hydroxide extract with residual pectin. The low abundance of both phenolics and protein was also confirmed. The first sodium carbonate extraction almost completely removes esters remaining in the cell wall. We have demonstrated that FTIR spectroscopy can detect large conformational changes in pectic polymers on removal from the cell wall and on drying. FTIR spectroscopy provides a powerful and rapid assay for wall components and putative cross-links by identifying polymers and functional groups nondestructively in muro. The availability of micro-sampling and data acquisition techniques that permit subtraction of the blanket absorption of water make FTIR spectroscopy particularly suitable for studies of cell wall architecture. The use of polarizers with the microscope accessory permits determination of the orientation of particular functional groups with respect to the direction of cell elongation in carrot suspension cells. PMID:16653221

  3. Quantum chemical computations and Fourier transform infrared spectral studies of a nonlinear food dye E110

    NASA Astrophysics Data System (ADS)

    Snehalatha, M.; Sekar, N.; Jayakumar, V. S.; Joe, I. Hubert

    2008-01-01

    Fourier transform infrared (FTIR) spectrum of a well-known food dye sunset yellow FCF (E110) has been recorded and analysed. Assignments of the vibrational spectrum has been facilitated by density functional theory (DFT) calculations. The results of the optimized molecular structure obtained on the basis of B3LYP with 6-31G(d) along with the 'LANL2DZ' basis sets give clear evidence for the intramolecular charge transfer (ICT) and strong hydrogen bonding enhancing the optical nonlinearity of the molecule. The first hyperpolarizability of the acidic monoazo dye 'E110' is computed. Azo stretching frequencies have been lowered due to conjugation and π-electron delocalization. Hydroxyl vibrations with intramolecular H-bonding are analyzed, supported by the computed results. The natural bond orbitals (NBO) analysis confirms this strong hydrogen bond between the hydrogen of the hydroxyl group and nitrogen of the azo group of the molecule. Assignments of benzene and naphthalene ring vibrations are found to agree well with the theoretical wave numbers.

  4. Fourier Transform Infrared Spectroscopic Imaging of Fracture Healing in the Normal Mouse

    PubMed Central

    Gollwitzer, Hans; Yang, Xu; Spevak, Lyudmila; Lukashova, Lyudmila; Nocon, Allina; Fields, Kara; Pleshko, Nancy; Courtland, Hayden William; Bostrom, Mathias P.; Boskey, Adele L.

    2015-01-01

    Fourier transform infrared spectroscopic imaging (FTIRI) was used to study bone healing with spatial analysis of various callus tissues in wild type mice. Femoral fractures were produced in 28 male C57BL mice by osteotomy. Animals were sacrificed at 1, 2, 4, and 8 weeks to obtain callus tissue at well-defined healing stages. Following microcomputerized tomography, bone samples were cut in consecutive sections for FTIRI and histology, allowing for spatial correlation of both imaging methods in different callus areas (early calcified cartilage, woven bone, areas of intramembranous and endochondral bone formation). Based on FTIRI, mineral/matrix ratio increased significantly during the first 4 weeks of fracture healing in all callus areas and correlated with bone mineral density measured by micro-CT. Carbonate/phosphate ratio was elevated in newly formed calcified tissue and at week 2 attained values comparable to cortical bone. Collagen maturity and mineral crystallinity increased during weeks 1–8 in most tissues while acid phosphate substitution decreased. Temporal and callus area dependent changes were detected throughout the healing period. These data assert the usefulness of FTIRI for evaluation of fracture healing in the mouse and its potential to evaluate pathologic fracture healing and the effects of therapeutic interventions. PMID:26034749

  5. Identification of Yersinia ruckeri from diseased salmonid fish by Fourier transform infrared spectroscopy.

    PubMed

    Wortberg, F; Nardy, E; Contzen, M; Rau, J

    2012-01-01

    Yersinia ruckeri is the causative agent of enteric redmouth disease (ERM), which mainly affects salmonid fish. Isolates of Y. ruckeri from diseased salmonid fish were obtained over a 6-year period from eight fish farms in the State of Baden-Württemberg, Southwest Germany. The strains were characterized by biochemical methods and Fourier transform infrared spectroscopy (FT-IR) combined with artificial neural network analysis. These methods were complemented by 16S rDNA sequencing for several isolates. The set of strains from these fish farms included sorbitol-positive, gelatinase-positive and non-motile Y. ruckeri. These variants were differentiated with an advanced FT-IR module, which is part of a higher-ranking method including more than 200 well-defined Yersinia strains against a background of more than 1000 other Gram-negative isolates. Validation of the newly constructed method yielded 97.4% of Y. ruckeri identified correctly on the species level. Thus, the FT-IR analysis enables distinction of all Y. ruckeri from other Yersinia species (e.g. fish-borne Y. enterocolitica) and other Enterobacteriaceae typically misidentified because of similar biochemical reaction profiles, especially Hafnia alvei. The differentiation of sorbitol-positive variants of Y. ruckeri using FT-IR was demonstrated. PMID:22103737

  6. High-resolution subtyping of Staphylococcus aureus strains by means of Fourier-transform infrared spectroscopy.

    PubMed

    Johler, Sophia; Stephan, Roger; Althaus, Denise; Ehling-Schulz, Monika; Grunert, Tom

    2016-05-01

    Staphylococcus aureus causes a variety of serious illnesses in humans and animals. Subtyping of S. aureus isolates plays a crucial role in epidemiological investigations. Metabolic fingerprinting by Fourier-transform infrared (FTIR) spectroscopy is commonly used to identify microbes at species as well as subspecies level. In this study, we aimed to assess the suitability of FTIR spectroscopy as a tool for S. aureus subtyping. To this end, we compared the subtyping performance of FTIR spectroscopy to other subtyping methods such as pulsed field gel electrophoresis (PFGE) and spa typing in a blinded experimental setup and investigated the ability of FTIR spectroscopy for identifying S. aureus clonal complexes (CC). A total of 70 S. aureus strains from human, animal, and food sources were selected, for which clonal complexes and a unique virulence and resistance gene pattern had been determined by DNA microarray analysis. FTIR spectral analysis resulted in high discriminatory power similar as obtained by spa typing and PFGE. High directional concordance was found between FTIR spectroscopy based subtypes and capsular polysaccharide expression detected by FTIR spectroscopy and the cap specific locus, reflecting strain specific expression of capsular polysaccharides and/or other surface glycopolymers, such as wall teichoic acid, peptidoglycane, and lipoteichoic acid. Supervised chemometrics showed only limited possibilities for differentiation of S. aureus CC by FTIR spectroscopy with the exception of CC45 and CC705. In conclusion, FTIR spectroscopy represents a valuable tool for S. aureus subtyping, which complements current molecular and proteomic strain typing. PMID:27021524

  7. Vibrational mapping of sinonasal lesions by Fourier transform infrared imaging spectroscopy

    NASA Astrophysics Data System (ADS)

    Giorgini, Elisabetta; Sabbatini, Simona; Conti, Carla; Rubini, Corrado; Rocchetti, Romina; Re, Massimo; Vaccari, Lisa; Mitri, Elisa; Librando, Vito

    2015-12-01

    Fourier transform infrared imaging (FTIRI) is a powerful tool for analyzing biochemical changes in tumoral tissues. The head and neck region is characterized by a great variety of lesions, with different degrees of malignancy, which are often difficult to diagnose. Schneiderian papillomas are sinonasal benign neoplasms arising from the Schneiderian mucosa; they can evolve into malignant tumoral lesions (squamous cell carcinoma). In addition, they can sometimes be confused with the more common inflammatory polyps. Therefore, an early and definitive diagnosis of this pathology is mandatory. Progressing in our research on the study of oral cavity lesions, 15 sections consisting of inflammatory sinonasal polyps, benign Schneiderian papillomas, and sinonasal undifferentiated carcinomas were analyzed using FTIRI. To allow a rigorous description of these pathologies and to gain objective diagnosis, the epithelial layer and the adjacent connective tissue of each section were separately investigated by following a multivariate analysis approach. According to the nature of the lesion, interesting modifications were detected in the average spectra of the different tissue components, above all in the lipid and protein patterns. Specific band-area ratios acting as spectral markers of the different pathologies were also highlighted.

  8. Fourier transform infrared spectroscopy provides an evidence of papain denaturation and aggregation during cold storage.

    PubMed

    Rašković, Brankica; Popović, Milica; Ostojić, Sanja; Anđelković, Boban; Tešević, Vele; Polović, Natalija

    2015-01-01

    Papain is a cysteine protease with wide substrate specificity and many applications. Despite its widespread applications, cold stability of papain has never been studied. Here, we used differential spectroscopy to monitor thermal denaturation process. Papain was the most stabile from 45 °C to 60 °C with ΔG°321 of 13.9±0.3 kJ/mol and Tm value of 84±1 °C. After cold storage, papain lost parts of its native secondary structures elements which gave an increase of 40% of intermolecular β-sheet content (band maximum detected at frequency of 1621 cm(-1) in Fourier transform infrared (FT-IR) spectrum) indicating the presence of secondary structures necessary for aggregation. The presence of protein aggregates after cold storage was also proven by analytical size exclusion chromatography. After six freeze-thaw cycles around 75% of starting enzyme activity of papain was lost due to cold denaturation and aggregation of unfolded protein. Autoproteolysis of papain did not cause significant loss of the protein activity. Upon the cold storage, papain underwent structural rearrangements and aggregation that correspond to other cold denatured proteins, rather than autoproteolysis which could have the commercial importance for the growing polypeptide based industry. PMID:26051646

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

    NASA Technical Reports Server (NTRS)

    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.

  10. Fourier transform infrared spectroscopy provides an evidence of papain denaturation and aggregation during cold storage.

    PubMed

    Rašković, Brankica; Popović, Milica; Ostojić, Sanja; Anđelković, Boban; Tešević, Vele; Polović, Natalija

    2015-01-01

    Papain is a cysteine protease with wide substrate specificity and many applications. Despite its widespread applications, cold stability of papain has never been studied. Here, we used differential spectroscopy to monitor thermal denaturation process. Papain was the most stabile from 45 °C to 60 °C with ΔG°321 of 13.9±0.3 kJ/mol and Tm value of 84±1 °C. After cold storage, papain lost parts of its native secondary structures elements which gave an increase of 40% of intermolecular β-sheet content (band maximum detected at frequency of 1621 cm(-1) in Fourier transform infrared (FT-IR) spectrum) indicating the presence of secondary structures necessary for aggregation. The presence of protein aggregates after cold storage was also proven by analytical size exclusion chromatography. After six freeze-thaw cycles around 75% of starting enzyme activity of papain was lost due to cold denaturation and aggregation of unfolded protein. Autoproteolysis of papain did not cause significant loss of the protein activity. Upon the cold storage, papain underwent structural rearrangements and aggregation that correspond to other cold denatured proteins, rather than autoproteolysis which could have the commercial importance for the growing polypeptide based industry.

  11. Discrimination of the Acinetobacter calcoaceticus-Acinetobacter baumannii complex species by Fourier transform infrared spectroscopy.

    PubMed

    Sousa, C; Silva, L; Grosso, F; Nemec, A; Lopes, J; Peixe, L

    2014-08-01

    The main goal of this work was to assess the ability of Fourier transform infrared spectroscopy with attenuated total reflectance (FTIR-ATR) to discriminate between the species of the Acinetobacter calcoaceticus-Acinetobacter baumannii (Acb) complex, i.e. A. baumannii, A. nosocomialis, A. pittii, A. calcoaceticus, genomic species "Between 1 and 3" and genomic species "Close to 13TU". A total of 122 clinical isolates of the Acb complex previously identified by rpoB sequencing were studied. FTIR-ATR spectra was analysed by partial least squares discriminant analysis (PLSDA) and the model scores were presented in a dendrogram form. This spectroscopic technique proved to be effective in the discrimination of the Acb complex species, with sensitivities from 90 to 100%. Moreover, a flowchart aiming to help with species identification was developed and tested with 100% correct predictions for A. baumannii, A. nosocomialis and A. pittii test isolates. This rapid, low cost and environmentally friendly technique proved to be a reliable alternative for the identification of these closely related Acinetobacter species that share many clinical and epidemiological characteristics and are often difficult to distinguish. Its validation towards application on a routine basis could revolutionise high-throughput bacterial identification.

  12. Determination of the stability of laser deposited apatite coatings in phosphate buffered saline solution using Fourier transform infrared (FTIR) spectroscopy

    NASA Astrophysics Data System (ADS)

    Antonov, E. N.; Bagratashvili, V. N.; Popov, V. K.; Sobol, E. N.; Howdle, S. M.

    1996-01-01

    We report the use of grazing angle Fourier transform infrared spectroscopy for determination of the stability to erosion of hydroxyapatite coatings. A series of coatings were deposited by pulsed laser ablation onto titanium foils. The coatings were exposed to a phosphate buffered saline solution, and FTIR spectroscopy was used to monitor the depletion of infrared bands associated with phosphate moieties in the hydroxyapatite coatings. The technique allows determintion of the effects of the laser deposition parameters upon the stability to erosion of the coatings.

  13. Analysis of Chuanxiong Rhizoma and its active components by Fourier transform infrared spectroscopy combined with two-dimensional correlation infrared spectroscopy.

    PubMed

    Guo, Yizhen; Lv, Beiran; Wang, Jingjuan; Liu, Yang; Sun, Suqin; Xiao, Yao; Lu, Lina; Xiang, Li; Yang, Yanfang; Qu, Lei; Meng, Qinghong

    2016-01-15

    As complicated mixture systems, active components of Chuanxiong Rhizoma are very difficult to identify and discriminate. In this paper, the macroscopic IR fingerprint method including Fourier transform infrared spectroscopy (FT-IR), the second derivative infrared spectroscopy (SD-IR) and two-dimensional correlation infrared spectroscopy (2DCOS-IR), was applied to study and identify Chuanxiong raw materials and its different segmented production of HPD-100 macroporous resin. Chuanxiong Rhizoma is rich in sucrose. In the FT-IR spectra, water eluate is more similar to sucrose than the powder and the decoction. Their second derivative spectra amplified the differences and revealed the potentially characteristic IR absorption bands and combined with the correlation coefficient, concluding that 50% ethanol eluate had more ligustilide than other eluates. Finally, it can be found from 2DCOS-IR spectra that proteins were extracted by ethanol from Chuanxiong decoction by HPD-100 macroporous resin. It was demonstrated that the above three-step infrared spectroscopy could be applicable for quick, non-destructive and effective analysis and identification of very complicated and similar mixture systems of traditional Chinese medicines. PMID:26439523

  14. Analysis of Chuanxiong Rhizoma and its active components by Fourier transform infrared spectroscopy combined with two-dimensional correlation infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Guo, Yizhen; Lv, Beiran; Wang, Jingjuan; Liu, Yang; Sun, Suqin; Xiao, Yao; Lu, Lina; Xiang, Li; Yang, Yanfang; Qu, Lei; Meng, Qinghong

    2016-01-01

    As complicated mixture systems, active components of Chuanxiong Rhizoma are very difficult to identify and discriminate. In this paper, the macroscopic IR fingerprint method including Fourier transform infrared spectroscopy (FT-IR), the second derivative infrared spectroscopy (SD-IR) and two-dimensional correlation infrared spectroscopy (2DCOS-IR), was applied to study and identify Chuanxiong raw materials and its different segmented production of HPD-100 macroporous resin. Chuanxiong Rhizoma is rich in sucrose. In the FT-IR spectra, water eluate is more similar to sucrose than the powder and the decoction. Their second derivative spectra amplified the differences and revealed the potentially characteristic IR absorption bands and combined with the correlation coefficient, concluding that 50% ethanol eluate had more ligustilide than other eluates. Finally, it can be found from 2DCOS-IR spectra that proteins were extracted by ethanol from Chuanxiong decoction by HPD-100 macroporous resin. It was demonstrated that the above three-step infrared spectroscopy could be applicable for quick, non-destructive and effective analysis and identification of very complicated and similar mixture systems of traditional Chinese medicines.

  15. Discrimination of different genuine Danshen and their extracts by Fourier transform infrared spectroscopy combined with two-dimensional correlation infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Liu, Xin-hu; Xu, Chang-hua; Sun, Su-qin; Huang, Jian; Zhang, Ke; Li, Guo-yu; Zhu, Yun; Zhou, Qun; Zhang, Zhi-cheng; Wang, Jin-hui

    2012-11-01

    In this study, six varieties of Danshen from different populations and genuine ("Daodi" in Chinese transliteration) regions were discriminated and identified by a three-step infrared spectroscopy method (Fourier transform-infrared spectroscopy (FT-IR) coupled with second derivative infrared spectroscopy (SD-IR) and two dimensional correlation infrared spectroscopy (2D-IR)). Though only small differences were found among the FT-IR spectra of the six Danshen samples, the positions and intensities of peaks at 3393, 3371, 1613, 1050, and 1036 cm-1 could be considered as the key factors to discriminate them. More significant differences were exhibited in their SD-IR, particularly for the peaks around 1080, 1144, 695, 665, 800, 1610, 1510, 1450, 1117 and 1077 cm-1. The visual 2D-IR spectra provided dynamic chemical structure information of the six Danshen samples with presenting different particular auto-peak clusters, respectively. Moreover, the contents of salvianolic acid B in all samples were measured quantitatively by a validated ultra performance liquid chromatography (UPLC), which was consistent with the FT-IR findings. This study provides a promising method for characteristics and quality control of the complicated and extremely similar herbal medicine like Danshen, which is more cost effective and time saving.

  16. Analysis of Chuanxiong Rhizoma and its active components by Fourier transform infrared spectroscopy combined with two-dimensional correlation infrared spectroscopy.

    PubMed

    Guo, Yizhen; Lv, Beiran; Wang, Jingjuan; Liu, Yang; Sun, Suqin; Xiao, Yao; Lu, Lina; Xiang, Li; Yang, Yanfang; Qu, Lei; Meng, Qinghong

    2016-01-15

    As complicated mixture systems, active components of Chuanxiong Rhizoma are very difficult to identify and discriminate. In this paper, the macroscopic IR fingerprint method including Fourier transform infrared spectroscopy (FT-IR), the second derivative infrared spectroscopy (SD-IR) and two-dimensional correlation infrared spectroscopy (2DCOS-IR), was applied to study and identify Chuanxiong raw materials and its different segmented production of HPD-100 macroporous resin. Chuanxiong Rhizoma is rich in sucrose. In the FT-IR spectra, water eluate is more similar to sucrose than the powder and the decoction. Their second derivative spectra amplified the differences and revealed the potentially characteristic IR absorption bands and combined with the correlation coefficient, concluding that 50% ethanol eluate had more ligustilide than other eluates. Finally, it can be found from 2DCOS-IR spectra that proteins were extracted by ethanol from Chuanxiong decoction by HPD-100 macroporous resin. It was demonstrated that the above three-step infrared spectroscopy could be applicable for quick, non-destructive and effective analysis and identification of very complicated and similar mixture systems of traditional Chinese medicines.

  17. Chemical morphology of Areca nut characterized directly by Fourier transform near-infrared and mid-infrared microspectroscopic imaging in reflection modes.

    PubMed

    Chen, Jian-Bo; Sun, Su-Qin; Zhou, Qun

    2016-12-01

    Fourier transform near-infrared (NIR) and mid-infrared (MIR) imaging techniques are essential tools to characterize the chemical morphology of plant. The transmission imaging mode is mostly used to obtain easy-to-interpret spectra with high signal-to-noise ratio. However, the native chemical compositions and physical structures of plant samples may be altered when they are microtomed for the transmission tests. For the direct characterization of thick plant samples, the combination of the reflection NIR imaging and the attenuated total reflection (ATR) MIR imaging is proposed in this research. First, the reflection NIR imaging method can explore the whole sample quickly to find out typical regions in small sizes. Next, each small typical region can be measured by the ATR-MIR imaging method to reveal the molecular structures and spatial distributions of compounds of interest. As an example, the chemical morphology of Areca nut section is characterized directly by the above approach.

  18. [Tracking analysis of three extraction processes of Arenaria Polytrichoides by Fourier transform infrared spectrocopy].

    PubMed

    Ma, Jing; Wu, Xian-Xue; Tai, Xi; Xu, Liu-Xian; Zhu, Jin-Lan; Qin, Yao; Zhou, Qun; Sun, Su-Qin

    2014-10-01

    In order to develop a process analysis method to guide extraction process of Arenaria polytrichoides (AP) based on tracking analysis by Fourier transform infrared (FTIR), IR spectra of petroleum ether extracts (PE-E), ethyl acetate extracts (EtOAc-E), n-butanol extracts (n-BuOH-E) and water extracts (H2O-E) of AP from three extraction methods were recorded. The FTIR and corresponding second derivative infrared (SDIR) spectra were analyzed comparatively from two aspects, namely, different extracts from a same extraction process and the same extracts from different methods. The spectral analysis results show that different extracts obtained from a same extraction process have distinctly different spectral absorbance character. Although the IR spectral absorption characteristics of the same extracts from different methods are rather similar in holistic, some explicit spectral differences still could be found among each other. In extraction process one (M1), main flavonoids and their glycosides of AP migrated to EtOAc-E and the rest part of them shift to n-BuOH-E according to FTIR peaks such as 1,603 and 1,123 cm(-1). However, the circumstances in method two (M2) and method three (M3) were just the reverse. Moreover, a few flavonoid glycosides got into H2O-E. The relative content of all kinds of aglycones and higher saturated alkyl are much higher in EtOAc-E of M2 than that of M1 and M3 according to the relative absorption intensive of peak at 2,850 cm(-1). Similarly, n-BuOH-E of M3 has relative rich contents of glycosides: and polysaccharides than those of M1 and M2 by peaks, such as 1,066 and 2,927 cm(-1). These results demonstrate that the migration rules of AP components are not always same in different extrac- tion process. The substance migration information during the extraction process could be recorded and disclosed in an intuitive way by FTIR tracking analysis of corresponding extracts. Consequently, FTIR tracking analysis is a fast, efficient, low-carbon and

  19. Multipass open-path Fourier-transform infrared measurements for nonintrusive monitoring of gas turbine exhaust composition.

    PubMed

    Schäfer, Klaus; Brockmann, Klaus; Heland, Jörg; Wiesen, Peter; Jahn, Carsten; Legras, Olivier

    2005-04-10

    The detection limits for NO and NO2 in turbine exhausts by nonintrusive monitoring have to be improved. Multipass mode Fourier-transform infrared (FTIR) absorption spectrometry and use of a White mirror system were found from a sensitivity study with spectra simulations in the mid-infrared to be essential for the retrieval of NO2 abundances. A new White mirror system with a parallel infrared beam was developed and tested successfully with a commercial FTIR spectrometer in different turbine test beds. The minimum detection limits for a typical turbine plume of 50 cm in diameter are approximately 6 parts per million (ppm) for NO and 9 ppm for NO2 (as well 100 ppm for CO2 and 4 ppm for CO).

  20. Discrimination of Astyanax altiparanae (Characiformes, Characidae) populations by applying Fourier transform-infrared photoacoustic spectroscopy in the fish scales

    NASA Astrophysics Data System (ADS)

    de Almeida, F. S.; Santana, C. A.; Lima, D. M. V.; Andrade, L. H. C.; Súarez, Y. R.; Lima, S. M.

    2016-05-01

    Astyanax altiparanae fish species is considered very generalist and opportunist, occupying different types and sizes of environments. This characteristic turns it very appropriate as bioindicator or biomarked. Therefore, in this work, A. altiparanae fish species was used to identify populations by using the Fourier transform infrared spectroscopy directly in its scales. The discriminant analysis applied in the infrared spectra demonstrated a significant differentiation among the analyzed populations, with the first and second canonical roots explain together 100% of the data variation. The obtained results were correlated with environmental descriptors and diet of fishes, and a better agreement was obtained when spectroscopic data were compared with the composition of food present in the fish stomachs. However, this study indicates that the combination of infrared absorption spectroscopy with discriminant analysis is a very appropriate methodology to be used in fish scales as bioindicator for intraspecific study.

  1. On-line preferential solvation studies of polymers by coupled chromatographic-Fourier transform infrared spectroscopic flow-cell technique.

    PubMed

    Malanin, M; Eichhorn, K-J; Lederer, A; Treppe, P; Adam, G; Fischer, D; Voigt, D

    2009-12-18

    Qualitative and quantitative comparison between liquid chromatography (LC) and LC coupled with Fourier transform infrared spectroscopy (LC-FTIR) to evaluate preferential solvation phenomenon of polymers in a mixed solvent has been performed. These studies show that LC-FTIR technique leads to detailed structural information without the requirement for determination of additional parameters for quantitative analysis except calibration. Appropriate experimental conditions for preferential solvation study have been established by variation of polymer concentration, molar mass and eluent content.

  2. Vibrational spectroscopy of a transient species through time-resolved Fourier transform infrared emission spectroscopy: The vinyl radical

    SciTech Connect

    Letendre, Laura; Liu, Dean-Kuo; Pibel, Charles D.; Halpern, Joshua B.; Dai, Hai-Lung

    2000-06-01

    An approach for detecting the vibrational spectrum of transient species is demonstrated on the vinyl radical. Photodissociation of carefully chosen precursors at selected photolysis wavelengths produce highly vibrationally excited radicals. Infrared (IR) emission from these radicals is then measured by time-resolved Fourier transform spectroscopy with nanosecond time resolution. All nine vibrational bands of the vinyl radical, generated from four different precursors, are obtained and reported here for the first time. (c) 2000 American Institute of Physics.

  3. Analysis of aircraft exhausts with Fourier-transform infrared emission spectroscopy.

    PubMed

    Heland, J; Schäfer, K

    1997-07-20

    Because of the worldwide growth in air traffic and its increasing effects on the atmospheric environment, it is necessary to quantify the direct aircraft emissions at all altitudes. In this study Fourier-transform infrared emission spectroscopy as a remote-sensing multi-component-analyzing technique for aircraft exhausts was investigated at ground level with a double pendulum interferometer and a line-by-line computer algorithm that was applied to a multilayer radiative transfer problem. Initial measurements were made to specify the spectral windows for traceable compounds, to test the sensitivity of the system, and to develop calibration and continuum handling procedures. To obtain information about the radial temperature and concentration profiles, we developed an algorithm for the analysis of an axial-symmetric multilayered plume by use of the CO(2) hot band at approximately 2400 cm(-1). Measurements were made with several in-service engines. Effects that were due to engine aging were detected but have to be analyzed systematically in the near future. Validation measurements were carried out with a conventional propane gas burner to compare the results with those obtained with standard measurement equipment. These measurements showed good agreement to within +/-20% for the CO and NO(x) results. The overall accuracy of the system was found to be +/-30%. The detection limits of the system for a typical engine plume (380 degrees C, ? = 50 cm) are below 0.1% for CO(2), ~0.7% for H(2)O, ~20 ppmv (parts per million by volume) for CO, and ~90 ppmv for NO.

  4. Study of tissue engineered bone nodules by Fourier transform infrared spectroscopy.

    PubMed

    Aydin, Halil Murat; Hu, Bin; Suso, Josep Sulé; El Haj, Alicia; Yang, Ying

    2011-02-21

    The key criteria for assessing the success of bone tissue engineering are the quality and quantity of the produced minerals within the cultured constructs. The accumulation of calcium ions and inorganic phosphates in culture medium serves as nucleating agents for the formation of hydroxyapatite, which is the main inorganic component of bone. Bone nodule formation is one of the hallmarks of mineralization in such cell cultures. In this study, we developed a new two-step procedure to accelerate bone formation in which mouse bone cell aggregates were produced first on various chemically treated non-adhesive substrates. After this step, the bone cells' growth and mineralization were followed in conventional culture plates. The number and size of cell aggregates were studied with light microscopy. The minerals' formation in the form of nodules produced by the cell aggregates and the bone crystal quality were studied with Fourier Transform Infrared (FTIR) spectroscopy. The FTIR spectra of the ash specimens (mineral phase only) from thermal gravimetric analysis (TGA) provided valuable information of the quality of the minerals. The υ(4) PO(4) region (550-650 cm(-1)), which reveals apatitic and non-apatitic HPO(4) or PO(4) environments, and phosphate region (910-1180 cm(-1)) were examined for the minerals produced in the form of nodules. The peak position and intensity of the spectra demonstrate that the quality of the bone produced by cell aggregates, especially from the bigger ones, which were formed on Plunoric treated substrates, exhibit a composition more similar to that of native bone. This work establishes a new protocol for high quality bone formation and characterization, with the potential to be applied to bone tissue engineering.

  5. Fourier transform infrared spectroscopic imaging parameters describing acid phosphate substitution in biologic hydroxyapatite.

    PubMed

    Spevak, Lyudmila; Flach, Carol R; Hunter, Tracey; Mendelsohn, Richard; Boskey, Adele

    2013-05-01

    Acid phosphate substitution into mineralized tissues is an important determinant of their mechanical properties and their response to treatment. This study identifies and validates Fourier transform infrared spectroscopic imaging (FTIRI) spectral parameters that provide information on the acid phosphate (HPO4) substitution into hydroxyapatite in developing mineralized tissues. Curve fitting and Fourier self-deconvolution were used to identify subband positions in model compounds (with and without HPO4). The intensity of subbands at 1127 and 1110 cm(-1) correlated with the acid phosphate content in these models. Peak height ratios of these subbands to the ν3 vibration at 1096 cm(-1) found in stoichiometric apatite were evaluated in the model compounds and mixtures thereof. FTIRI spectra of bones and teeth at different developmental ages were analyzed using these spectral parameters. Factor analysis (a chemometric technique) was also conducted on the tissue samples and resulted in factor loadings with spectral features corresponding to the HPO4 vibrations described above. Images of both factor correlation coefficients and the peak height ratios 1127/1096 and 1112/1096 cm(-1) demonstrated higher acid phosphate content in younger vs. more mature regions in the same specimen. Maps of the distribution of acid phosphate content will be useful for characterizing the extent of new bone formation, the areas of potential decreased strength, and the effects of therapies such as those used in metabolic bone diseases (osteoporosis, chronic kidney disease) on mineral composition. Because of the wider range of values obtained with the 1127/1096 cm(-1) parameter compared to the 1110/1096 cm(-1) parameter and the smaller scatter in the slope, it is suggested that this ratio should be the parameter of choice.

  6. Determination of aluminium induced metabolic changes in mice liver: A Fourier transform infrared spectroscopy study

    NASA Astrophysics Data System (ADS)

    Sivakumar, S.; Sivasubramanian, J.; Khatiwada, Chandra Prasad; Manivannan, J.; Raja, B.

    2013-06-01

    In this study, we made a new approach to evaluate aluminium induced metabolic changes in liver tissue of mice using Fourier transform infrared spectroscopy analysis taking one step further in correlation with strong biochemical evidence. This finding reveals the alterations on the major biochemical constituents, such as lipids, proteins, nucleic acids and glycogen of the liver tissues of mice. The peak area value of amide A significantly decrease from 288.278 ± 3.121 to 189.872 ± 2.012 between control and aluminium treated liver tissue respectively. Amide I and amide II peak area value also decrease from 40.749 ± 2.052 to 21.170 ± 1.311 and 13.167 ± 1.441 to 8.953 ± 0.548 in aluminium treated liver tissue respectively. This result suggests an alteration in the protein profile. The absence of olefinicdbnd CH stretching band and Cdbnd O stretching of triglycerides in aluminium treated liver suggests an altered lipid levels due to aluminium exposure. Significant shift in the peak position of glycogen may be the interruption of aluminium in the calcium metabolism and the reduced level of calcium. The overall findings exhibit that the liver metabolic program is altered through increasing the structural modification in proteins, triglycerides and quantitative alteration in proteins, lipids, and glycogen. All the above mentioned modifications were protected in desferrioxamine treated mice. Histopathological results also revealed impairment of aluminium induced alterations in liver tissue. The results of the FTIR study were found to be in agreement with biochemical studies and which demonstrate FTIR can be used successfully to indicate the molecular level changes.

  7. Determination of aluminium induced metabolic changes in mice liver: a Fourier transform infrared spectroscopy study.

    PubMed

    Sivakumar, S; Sivasubramanian, J; Khatiwada, Chandra Prasad; Manivannan, J; Raja, B

    2013-06-01

    In this study, we made a new approach to evaluate aluminium induced metabolic changes in liver tissue of mice using Fourier transform infrared spectroscopy analysis taking one step further in correlation with strong biochemical evidence. This finding reveals the alterations on the major biochemical constituents, such as lipids, proteins, nucleic acids and glycogen of the liver tissues of mice. The peak area value of amide A significantly decrease from 288.278±3.121 to 189.872±2.012 between control and aluminium treated liver tissue respectively. Amide I and amide II peak area value also decrease from 40.749±2.052 to 21.170±1.311 and 13.167±1.441 to 8.953±0.548 in aluminium treated liver tissue respectively. This result suggests an alteration in the protein profile. The absence of olefinicCH stretching band and CO stretching of triglycerides in aluminium treated liver suggests an altered lipid levels due to aluminium exposure. Significant shift in the peak position of glycogen may be the interruption of aluminium in the calcium metabolism and the reduced level of calcium. The overall findings exhibit that the liver metabolic program is altered through increasing the structural modification in proteins, triglycerides and quantitative alteration in proteins, lipids, and glycogen. All the above mentioned modifications were protected in desferrioxamine treated mice. Histopathological results also revealed impairment of aluminium induced alterations in liver tissue. The results of the FTIR study were found to be in agreement with biochemical studies and which demonstrate FTIR can be used successfully to indicate the molecular level changes.

  8. Fourier-transform infrared study of the photoactivation process of Xenopus (6-4) photolyase.

    PubMed

    Yamada, Daichi; Zhang, Yu; Iwata, Tatsuya; Hitomi, Kenichi; Getzoff, Elizabeth D; Kandori, Hideki

    2012-07-24

    Photolyases (PHRs) are blue light-activated DNA repair enzymes that maintain genetic integrity by reverting UV-induced photoproducts into normal bases. The flavin adenine dinucleotide (FAD) chromophore of PHRs has four different redox states: oxidized (FAD(ox)), anion radical (FAD(•-)), neutral radical (FADH(•)), and fully reduced (FADH(-)). We combined difference Fourier-transform infrared (FTIR) spectroscopy with UV-visible spectroscopy to study the detailed photoactivation process of Xenopus (6-4) PHR. Two photons produce the enzymatically active, fully reduced PHR from oxidized FAD: FAD(ox) is converted to semiquinone via light-induced one-electron and one-proton transfers and then to FADH(-) by light-induced one-electron transfer. We successfully trapped FAD(•-) at 200 K, where electron transfer occurs but proton transfer does not. UV-visible spectroscopy following 450 nm illumination of FAD(ox) at 277 K defined the FADH(•)/FADH(-) mixture and allowed calculation of difference FTIR spectra among the four redox states. The absence of a characteristic C=O stretching vibration indicated that the proton donor is not a protonated carboxylic acid. Structural changes in Trp and Tyr are suggested by UV-visible and FTIR analysis of FAD(•-) at 200 K. Spectral analysis of amide I vibrations revealed structural perturbation of the protein's β-sheet during initial electron transfer (FAD(•-) formation), a transient increase in α-helicity during proton transfer (FADH(•) formation), and reversion to the initial amide I signal following subsequent electron transfer (FADH(-) formation). Consequently, in (6-4) PHR, unlike cryptochrome-DASH, formation of enzymatically active FADH(-) did not perturb α-helicity. Protein structural changes in the photoactivation of (6-4) PHR are discussed on the basis of these FTIR observations. PMID:22747528

  9. Fourier transform infrared double-flash experiments resolve bacteriorhodopsin's M1 to M2 transition.

    PubMed Central

    Hessling, B; Herbst, J; Rammelsberg, R; Gerwert, K

    1997-01-01

    The orientation of the central proton-binding site, the protonated Schiff base, away from the proton release side to the proton uptake side is crucial for the directionality of the proton pump bacteriorhodopsin. It has been proposed that this movement, called the reprotonation switch, takes place in the M1 to M2 transition. To resolve the molecular events in this M1 to M2 transition, we performed double-flash experiments. In these experiments a first pulse initiates the photocycle and a second pulse selectively drives bR molecules in the M intermediate back into the BR ground state. For short delay times between initiating and resetting pulses, most of the M molecules being reset are in the M1 intermediate, and for longer delay times most of the reset M molecules are in the M2 intermediate. The BR-M1 and BR-M2 difference spectra are monitored with nanosecond step-scan Fourier transform infrared spectroscopy. Because the Schiff base reprotonation rate is kM1 = 0.8 x 10(7) s(-1) in the light-induced M1 back-reaction and kM2 = 0.36 x 10(7) s(-1) in the M2 back-reaction, the two different M intermediates represent two different proton accessibility configurations of the Schiff base. The results show only a minute movement of one or two peptide bonds in the M1 to M2 transition that changes the interaction of the Schiff base with Y185. This backbone movement is distinct from the larger one in the subsequent M to N transition. No evidence of a chromophore isomerization is seen in the M1 to M2 transition. Furthermore, the results show time-resolved reprotonation of the Schiff base from D85 in the M photo-back-reaction, instead of from D96, as in the conventional cycle. Images Scheme 2 PMID:9336202

  10. Detection, identification, and estimation of biological aerosols and vapors with a Fourier-transform infrared spectrometer

    NASA Astrophysics Data System (ADS)

    Ben-David, Avishai; Ren, Hsuan

    2003-08-01

    Two experiments were conducted with a Fourier-transform infrared (FTIR) spectrometer. The purpose of the first experiment was to detect and identify Bacillus subtilis subsp. niger (BG) bioaerosol spores and kaolin dust in an open-air release for which the thermal contrast between the aerosol temperature and background brightness temperature is small. The second experiment estimated the concentration of a small amount of triethyl phosphate (TEP) vapor in a closed chamber in which an external blackbody radiation source was used and where the thermal contrast was large. The deduced BG (TEP) extinction spectrum (identification) showed an excellent match to the library BG (TEP) extinction spectrum. Analysis of the time sequence of the measurements coincided well with the presence (detection) of the BG during the measurements, and the estimated concentration of time-dependent TEP vapor was excellent. The data were analyzed with hyperspectral detection, identification, and estimation algorithms. The algorithms were based on radiative transfer theory and statistical signal-processing methods. A subspace orthogonal projection operator was used to statistically subtract the large thermal background contribution to the measurements, and a robust maximum-likelihood solution was used to deduce the target (aerosol or vapor cloud) spectrum and estimate its mass-column concentration. A Gaussian-mixture probability model for the deduced mass-column concentration was computed with an expectation-maximization algorithm to produce the detection threshold, the probability of detection, and the probability of false alarm. The results of this study are encouraging, as they suggest for the first time to the authors' knowledge the feasibility of detecting biological aerosols with passive FTIR sensors.

  11. Infrared absorption of CH3OSO detected with time-resolved Fourier-transform spectroscopy

    NASA Astrophysics Data System (ADS)

    Chen, Jin-Dah; Lee, Yuan-Pern

    2011-03-01

    A step-scan Fourier-transform spectrometer coupled with a multipass absorption cell was employed to detect temporally resolved infrared absorption spectra of CH3OSO produced upon irradiation of a flowing gaseous mixture of CH3OS(O)Cl in N2 or CO2 at 248 nm. Two intense transient features with origins near 1152 and 994 cm-1 are assigned to syn-CH3OSO; the former is attributed to overlapping bands at 1154 ± 3 and 1151 ± 3 cm-1, assigned to the S=O stretching mixed with CH3 rocking (ν8) and the S=O stretching mixed with CH3 wagging (ν9) modes, respectively, and the latter to the C-O stretching (ν10) mode at 994 ± 6 cm-1. Two weak bands at 2991 ± 6 and 2956 ± 3 cm-1 are assigned as the CH3 antisymmetric stretching (ν2) and symmetric stretching (ν3) modes, respectively. Observed vibrational transition wavenumbers agree satisfactorily with those predicted with quantum-chemical calculations at level B3P86/aug-cc-pVTZ. Based on rotational parameters predicted at that level, the simulated rotational contours of these bands agree satisfactorily with experimental results. The simulation indicates that the S=O stretching mode of anti-CH3OSO near 1164 cm-1 likely makes a small contribution to the observed band near 1152 cm-1. A simple kinetic model of self-reaction is employed to account for the decay of CH3OSO and yields a second-order rate coefficient k = (4 ± 2)×10-10 cm3 molecule-1 s-1.

  12. High-Throughput Biochemical Fingerprinting of Saccharomyces cerevisiae by Fourier Transform Infrared Spectroscopy

    PubMed Central

    Kohler, Achim; Böcker, Ulrike; Shapaval, Volha; Forsmark, Annabelle; Andersson, Mats; Warringer, Jonas; Martens, Harald; Omholt, Stig W.; Blomberg, Anders

    2015-01-01

    Single-channel optical density measurements of population growth are the dominant large scale phenotyping methodology for bridging the gene-function gap in yeast. However, a substantial amount of the genetic variation induced by single allele, single gene or double gene knock-out technologies fail to manifest in detectable growth phenotypes under conditions readily testable in the laboratory. Thus, new high-throughput phenotyping technologies capable of providing information about molecular level consequences of genetic variation are sorely needed. Here we report a protocol for high-throughput Fourier transform infrared spectroscopy (FTIR) measuring biochemical fingerprints of yeast strains. It includes high-throughput cultivation for FTIR spectroscopy, FTIR measurements and spectral pre-treatment to increase measurement accuracy. We demonstrate its capacity to distinguish not only yeast genera, species and populations, but also strains that differ only by a single gene, its excellent signal-to-noise ratio and its relative robustness to measurement bias. Finally, we illustrated its applicability by determining the FTIR signatures of all viable Saccharomyces cerevisiae single gene knock-outs corresponding to lipid biosynthesis genes. Many of the examined knock-out strains showed distinct, highly reproducible FTIR phenotypes despite having no detectable growth phenotype. These phenotypes were confirmed by conventional lipid analysis and could be linked to specific changes in lipid composition. We conclude that the introduced protocol is robust to noise and bias, possible to apply on a very large scale, and capable of generating biologically meaningful biochemical fingerprints that are strain specific, even when strains lack detectable growth phenotypes. Thus, it has a substantial potential for application in the molecular functionalization of the yeast genome. PMID:25706524

  13. Evaluation of a Fourier transform infrared continuous emission monitor field test at a TSCA incinerator

    SciTech Connect

    Mao, Z.; Demirgian, J.C.; Reedy, G.

    1994-06-01

    A Fourier transform infrared (FTIR) spectrometer was field tested as a continuous emission monitor (CEM) at the Toxic Substances Control Act (TSCA) incinerator at K-25 in Oak Ridge, Tenn., from August 23 to September 3, 1993. This paper reports results obtained from this field test. The FTIR spectrometer and the long-path cell used for the field test were specially designed and constructed, so that optical alignment of the system can be easily performed in the field. The system was tested in the laboratory and then in the field for instrument stability and signal-to-noise ratio. Time interval required for taking a new background spectrum was determined. It appears that the system performs well both in the laboratory and in the field. The field test followed a standard operation procedure (SOP), developed for the test, based on a proposed EPA protocol for applying FTIR in emission testing. Sixteen compounds were selected as target analytes. Ethylene was used as a calibration transfer standard to ensure that spectral performance of the FTIR spectrometer in the field is consistent with that in the laboratory. Spike tests were regularly conducted with a known concentration of a mixture of six compounds and also with SF{sub 6} to check the accuracy of the monitoring system. Data sampling, processing, and reporting were automated to collect data every 10 min, and data were collected throughout the test as long as liquid nitrogen was available in the detector. The instrumentation and software performed flawlessly. Although the field test was a success, further improvement is necessary. Suggestions for revising the SOP and the proposed EPA protocol are discussed.

  14. Identification of Yersinia enterocolitica at the Species and Subspecies Levels by Fourier Transform Infrared Spectroscopy ▿

    PubMed Central

    Kuhm, Andrea Elisabeth; Suter, Daniel; Felleisen, Richard; Rau, Jörg

    2009-01-01

    Yersinia enterocolitica and other Yersinia species, such as Y. pseudotuberculosis, Y. bercovieri, and Y. intermedia, were differentiated using Fourier transform infrared spectroscopy (FT-IR) combined with artificial neural network analysis. A set of well defined Yersinia strains from Switzerland and Germany was used to create a method for FT-IR-based differentiation of Yersinia isolates at the species level. The isolates of Y. enterocolitica were also differentiated by FT-IR into the main biotypes (biotypes 1A, 2, and 4) and serotypes (serotypes O:3, O:5, O:9, and “non-O:3, O:5, and O:9”). For external validation of the constructed methods, independently obtained isolates of different Yersinia species were used. A total of 79.9% of Y. enterocolitica sensu stricto isolates were identified correctly at the species level. The FT-IR analysis allowed the separation of all Y. bercovieri, Y. intermedia, and Y. rohdei strains from Y. enterocolitica, which could not be differentiated by the API 20E test system. The probability for correct biotype identification of Y. enterocolitica isolates was 98.3% (41 externally validated strains). For correct serotype identification, the probability was 92.5% (42 externally validated strains). In addition, the presence or absence of the ail gene, one of the main pathogenicity markers, was demonstrated using FT-IR. The probability for correct identification of isolates concerning the ail gene was 98.5% (51 externally validated strains). This indicates that it is possible to obtain information about genus, species, and in the case of Y. enterocolitica also subspecies type with a single measurement. Furthermore, this is the first example of the identification of specific pathogenicity using FT-IR. PMID:19617388

  15. Accuracy of noninvasive breath methane measurements using Fourier transform infrared methods on individual cows.

    PubMed

    Lassen, J; Løvendahl, P; Madsen, J

    2012-02-01

    Individual methane (CH(4)) production was recorded repeatedly on 93 dairy cows during milking in an automatic milking system (AMS), with the aim of estimating individual cow differences in CH(4) production. Methane and CO(2) were measured with a portable air sampler and analyzer unit based on Fourier transform infrared (FTIR) detection. The cows were 50 Holsteins and 43 Jerseys from mixed parities and at all stages of lactation (mean=156 d in milk). Breath was captured by the FTIR unit inlet nozzle, which was placed in front of the cow's head in each of the 2 AMS as an admixture to normal barn air. The FTIR unit was running continuously for 3 d in each of 2 AMS units, 1 with Holstein and another with Jersey cows. Air was analyzed every 20 s. From each visit of a cow to the AMS, CH(4) and CO(2) records were summarized into the mean, median, 75, and 90% quantiles. Furthermore, the ratio between CH(4) and CO(2) was used as a derived measure with the idea of using CO(2) in breath as a tracer gas to quantify the production of methane. Methane production records were analyzed with a mixed model, containing cow as random effect. Fixed effects of milk yield and daily intake of the total mixed ration and concentrates were also estimated. The repeatability of the CH(4)-to-CO(2) ratio was 0.39 for Holsteins and 0.34 for Jerseys. Both concentrate intake and total mixed ration intake were positively related to CH(4) production, whereas milk production level was not correlated with CH(4) production. In conclusion, the results from this study suggest that the CH(4)-to-CO(2) ratio measured using the noninvasive method is an asset of the individual cow and may be useful in both management and genetic evaluations. PMID:22281353

  16. Predicting bovine milk protein composition based on Fourier transform infrared spectra.

    PubMed

    Rutten, M J M; Bovenhuis, H; Heck, J M L; van Arendonk, J A M

    2011-11-01

    Phenotypic information on individual protein composition of cows is important for many aspects of dairy processing with cheese production as the center of gravity. However, measuring individual protein composition is expensive and time consuming. In this study, we investigated whether protein composition can be predicted based on inexpensive and routinely measured milk Fourier transform infrared (FTIR) spectra. Based on 900 calibration and 900 validation samples that had both capillary zone electrophoresis (CZE)-determined protein composition and FTIR spectra available, low to moderate validation R(2) were reached (from 0.18 for α(S1)-casein to 0.56 for β-lactoglobulin). The potential usefulness of this model on the phenotypic level was investigated by means of achieved selection differentials for 25% of the best animals. For α-lactalbumin (R(2)=0.20), the selection differential amounted to 0.18 g/100g and for casein index (R(2)=0.50) to 1.24 g/100g. We concluded that predictions of protein composition were not accurate enough to enable selection of individual animals. However, for specific purposes when, for example, groups of animals that meet a certain threshold are to be selected, the presented model could be useful in practice on the phenotypic level. The potential usefulness of this model on the genetic level was investigated by means of genetic correlations between CZE-determined and FTIR-predicted protein composition traits. The genetic correlations ranged from 0.62 (β-casein) to 0.97 (whey). Thus, predictions of protein composition, when used as input to estimate breeding values, provide an excellent means for genetic improvement of protein composition. In addition, estimated repeatabilities based on 3 repeated observations of predicted protein composition showed that a considerable amount of prediction error can be removed using repeated observations.

  17. [Effects of fullerene soot on the thermal decomposition and Fourier transform infrared spectrum of PEG].

    PubMed

    Han, Xu; Li, Shu-fen; Zhao, Feng-qi; Pan, Qing; Yi, Jian-hua

    2008-12-01

    Effects of fullerene soot (FS) on the thermal decomposition and Fourier transform infrared spectrum (FTIR) of polyethylene glycol (PEG, molecular weight= 20,000) were investigated by thermal analysis (TG-DTG) and in-situ FTIR experiments. The results of thermal analytical experiments showed that the addition of FS postponed not only the initial decomposition temperatures but also the temperatures at maximum decomposition rate of PEG. The maximum decomposition peak temperatures increased and the maximum decomposition rates were lowered even with the addition of 0.1%FS. The in-situ FTIR experiments proved that there was no difference between the IR spectra of PEG and PEG with 10%FS. There wasn't any new chemical band formed but Vander waals force between FS and PEG. Although the addition of FS didn't influence the constitution of decomposition products of PEG, it obviously increased the decomposition temperature and the decomposition rate of PEG. Through the researches on condensed phase and gaseous phase FTIR spectrum of PEG and PEG with 10%FS, one could see that the effect of FS on the condensed phase FTIR spectrum of PEG was not obvious, but the addition of FS markedly enhanced the occurrence temperatures of most gaseous decomposition products of PEG. These results showed that the effect of FS on thermal decomposition of PEG was through the absorbance and desorption of gaseous phase decomposition products. With the temperature elevated, the gaseous products were gradually desorbed from the activity centers and the decomposition of PEG continued. The thermal decomposition peak of PEG was moved toward hi gher temperature with the addition of FS than that without FS.

  18. Cubic smoothing splines background correction in on-line liquid chromatography-Fourier transform infrared spectrometry.

    PubMed

    Kuligowski, Julia; Carrión, David; Quintás, Guillermo; Garrigues, Salvador; de la Guardia, Miguel

    2010-10-22

    A background correction method for the on-line coupling of gradient liquid chromatography and Fourier transform infrared spectrometry (LC-FTIR) is proposed. The developed approach applies univariate background correction to each variable (i.e. each wave number) individually. Spectra measured in the region before and after each peak cluster are used as knots to model the variation of the eluent absorption intensity with time using cubic smoothing splines (CSS) functions. The new approach has been successfully tested on simulated as well as on real data sets obtained from injections of standard mixtures of polyethylene glycols with four different molecular weights in methanol:water, 2-propanol:water and ethanol:water gradients ranging from 30 to 90, 10 to 25 and from 10 to 40% (v/v) of organic modifier, respectively. Calibration lines showed high linearity with coefficients of determination higher than 0.98 and limits of detection between 0.4 and 1.4, 0.9 and 1.8, and 1.1 and 2.7 mgmL⁻¹ in methanol:water, 2-propanol:water and ethanol:water, respectively. Furthermore the method performance has been compared with a univariate background correction approach based on the use of a reference spectra matrix (UBC-RSM) to discuss the potential as well as pitfalls and drawbacks of the proposed approach. This method works without previous variable selection and provides minimal user-interaction, thus increasing drastically the feasibility of on-line coupling of gradient LC-FTIR.

  19. Fourier transform infrared emission spectra of MgH and MgD

    NASA Astrophysics Data System (ADS)

    Shayesteh, A.; Appadoo, D. R. T.; Gordon, I.; Le Roy, R. J.; Bernath, P. F.

    2004-06-01

    High resolution Fourier transform infrared emission spectra of MgH and MgD have been recorded. The molecules were generated in an emission source that combines an electrical discharge with a high temperature furnace. Several vibration-rotation bands were observed for all six isotopomers in the X 2Σ+ ground electronic state: v=1→0 to 4→3 for 24MgH, v=1→0 to 3→2 for 25MgH and 26MgH, v=1→0 to 5→4 for 24MgD, v=1→0 to 4→3 for 25MgD and 26MgD. The new data were combined with the previous ground state data, obtained from diode laser vibration-rotation measurements and pure rotation spectra, and spectroscopic constants were determined for the v=0 to 4 levels of 24MgH and the v=0 to 5 levels of 24MgD. In addition, Dunham constants and Born-Oppenheimer breakdown correction parameters were obtained in a combined fit of the six isotopomers. The equilibrium vibrational constants (ωe) for 24MgH and 24MgD were found to be 1492.776(7) cm-1 and 1077.298(5) cm-1, respectively, while the equilibrium rotational constants (Be) are 5.825 523(8) cm-1 and 3.034 344(4) cm-1. The associated equilibrium bond distances (re) were determined to be 1.729 721(1) Å for 24MgH and 1.729 157(1) Å for 24MgD.

  20. Fourier transform infrared spectroscopic imaging identifies early biochemical markers of tissue damage

    NASA Astrophysics Data System (ADS)

    Varma, Vishal K.; Ohlander, Samuel; Nguyen, Peter; Vendryes, Christopher; Parthiban, Sujeeth; Hamilton, Blake; Wallis, M. Chad; Kajdacsy-Balla, Andre; Hannaford, Blake; Lendvay, Thomas; Hotaling, James M.; Walsh, Michael J.

    2014-03-01

    Fourier Transform Infrared (FT-IR) spectroscopic imaging can allow for the rapid imaging of tissue biochemistry in a label-free and non-perturbing fashion. With the rapid adoption of new minimally invasive surgery (MIS) technologies over the last 20 years, adequate skill to safely and effectively use these technologies may not be achieved and risk of undue physical pressure being placed on tissues is a concern. Previous work has demonstrated that a number of histological stains can detect tissue damage, however, this process requires the initiation and progression of a signaling cascade that results in the epitope of interest being expressed. We proposed to identify the early biochemical markers associated with physical tissue damage from applied forces, thus not requiring transcriptional and translational protein synthesis as traditional immunohistochemistry does. To demonstrate that FT-IR can measure biochemical changes in tissues that have undergone physical force, we took ex-vivo lamb's liver that had been freshly excised and applied varying levels of physical pressure (0kPa to 30kPa). Tissues were then formalin-fixed, paraffin-embedded, and sectioned on to glass for H and E staining to identify damage and on to an IR slide for FT-IR imaging. Regions of interest containing hepatocytes were identified and average FT-IR spectra were extracted from the damaged and undamaged livers. FT-IR spectra showed clear biochemical changes associated with tissue damage. In addition, chemical changes could be observed proceeding histological changes observed when using conventional staining approaches.

  1. FTIR (Fourier transform infrared) spectrophotometry for thin film monitors: Computer and equipment integration for enhanced capabilities

    SciTech Connect

    Cox, J.N.; Sedayao, J.; Shergill, G.; Villasol, R. ); Haaland, D.M. )

    1990-01-01

    Fourier transform infrared spectrophotometry (FTIR) is a valuable technique for monitoring thin films used in semiconductor device manufacture. Determinations of the constituent contents in borophosphosilicate (BPSG), phosphosilicate (PSG), silicon oxynitride (SiON:H,OH), and spin-on-glass (SOG) thin films are a few applications. Due to the nature of the technique, FTIR instrumentation is one of the most extensively computer-dependent pieces of equipment that is likely to be found in a microelectronics plant. In the role of fab monitor or reactor characterization tool, FTIR instruments can rapidly generate large amounts of data. By linking a local FTIR data station to a remote minicomputer its capabilities are greatly improved. We discuss three caused of enhancement. First, the FTIR in the fab area communicates and interacts in real time with the minicomputer: transferring data segments to it, instructing it to perform sophisticated processing, and returning the result to the operator in the fab. Characterizations of PSG thin films by this approach are discussed. Second, the spectra of large numbers of samples are processed locally. The large database is then transmitted to the minicomputer for study by statistical/graphics software. Results of CVD-reactor spatial profiling experiments for plasma SiON are presented. Third, processing of calibration spectra is performed on the minicomputer to optimize the accuracy and precision of a Partial Least Squares'' analysis mode. This model is then transferred to the data station in the fab. The analysis of BPSG thin films is discussed in this regard. The prospects for fully automated at-line monitoring and for real-time, in-situ monitoring will be discussed. 10 refs., 4 figs.

  2. Application of Fourier transform infrared (FTIR) spectroscopy for the identification of wheat varieties.

    PubMed

    Amir, Rai Muhammad; Anjum, Faqir Muhammad; Khan, Muhammad Issa; Khan, Moazzam Rafiq; Pasha, Imran; Nadeem, Muhammad

    2013-10-01

    Quality characteristics of wheat are determined by different physiochemical and rheological analysis by using different AACC methods. AACC methods are expensive, time consuming and cause destruction of samples. Fourier transforms infrared (FTIR) spectroscopy is one of the most important and emerging tool used for analyzing wheat for different quality parameters. This technique is rapid and sensitive with a great variety of sampling techniques. In the present study different wheat varieties were analyzed for quality assessment and were also characterized by using AACC methods and FTIR technique. The straight grade flour was analyzed for physical, chemical and rheological properties by standard methods and results were obtained. FTIR works on the basis of functional groups and provide information in the form of peaks. On basis of peaks the value of moisture, protein, fat, ash, carbohydrates and hardness of grain were determined. Peaks for water were observed in the range 1,640 cm(-1) and 3,300 cm(-1) on the basis of functional group H and OH. Protein was observed in the range from 1,600 cm(-1) to 1,700 cm(-1) and 1,550 cm(-1) to 1,570 cm(-1) on the basis of bond amide I and amide II respectively. Fat was also observed within these ranges but on the basis of C-H bond and also starch was observed in the range from 2,800 and 3,000 cm(-1) (C-H stretch region) and in the range 3,000 and 3,600 cm(-1) (O-H stretch region). As FTIR is a fast tool it can be easily emplyed for wheat varieties identification according to a set criterion. PMID:24426012

  3. Fingermark initial composition and aging using Fourier transform infrared microscopy (μ-FTIR).

    PubMed

    Girod, Aline; Xiao, Linda; Reedy, Brian; Roux, Claude; Weyermann, Céline

    2015-09-01

    This study investigated fingermark residues using Fourier transform infrared microscopy (μ-FTIR) in order to obtain fundamental information about the marks' initial composition and aging kinetics. This knowledge would be an asset for fundamental research on fingermarks, such as for dating purposes. Attenuated total reflection (ATR) and single-point reflection modes were tested on fresh fingermarks. ATR proved to be better suited and this mode was subsequently selected for further aging studies. Eccrine and sebaceous material was found in fresh and aged fingermarks and the spectral regions 1000-1850cm(-1) and 2700-3600cm(-1) were identified as the most informative. The impact of substrates (aluminium and glass slides) and storage conditions (storage in the light and in the dark) on fingermark aging was also studied. Chemometric analyses showed that fingermarks could be grouped according to their age regardless of the substrate when they were stored in an open box kept in an air-conditioned laboratory at around 20°C next to a window. On the contrary, when fingermarks were stored in the dark, only specimens deposited on the same substrate could be grouped by age. Thus, the substrate appeared to influence aging of fingermarks in the dark. Furthermore, PLS regression analyses were conducted in order to study the possibility of modelling fingermark aging for potential fingermark dating applications. The resulting models showed an overall precision of ±3 days and clearly demonstrated their capability to differentiate older fingermarks (20 and 34 days old) from newer ones (1, 3, 7 and 9 days old) regardless of the substrate and lighting conditions. These results are promising from a fingermark dating perspective. Further research is required to fully validate such models and assess their robustness and limitations in uncontrolled casework conditions. PMID:26254626

  4. Detection, identification, and estimation of biological aerosols and vapors with a Fourier-transform infrared spectrometer.

    PubMed

    Ben-David, Avishai; Ren, Hsuan

    2003-08-20

    Two experiments were conducted with a Fourier-transform infrared (FTIR) spectrometer. The purpose of the first experiment was to detect and identify Bacillus subtilis subsp. niger (BG) bioaerosol spores and kaolin dust in an open-air release for which the thermal contrast between the aerosol temperature and background brightness temperature is small. The second experiment estimated the concentration of a small amount of triethyl phosphate (TEP) vapor in a closed chamber in which an external blackbody radiation source was used and where the thermal contrast was large. The deduced BG (TEP) extinction spectrum (identification) showed an excellent match to the library BG (TEP) extinction spectrum. Analysis of the time sequence of the measurements coincided well with the presence (detection) of the BG during the measurements, and the estimated concentration of time-dependent TEP vapor was excellent. The data were analyzed with hyperspectral detection, identification, and estimation algorithms. The algorithms were based on radiative transfer theory and statistical signal-processing methods. A subspace orthogonal projection operator was used to statistically subtract the large thermal background contribution to the measurements, and a robust maximum-likelihood solution was used to deduce the target (aerosol or vapor cloud) spectrum and estimate its mass-column concentration. A Gaussian-mixture probability model for the deduced mass-column concentration was computed with an expectation-maximization algorithm to produce the detection threshold, the probability of detection, and the probability of false alarm. The results of this study are encouraging, as they suggest for the first time to the authors' knowledge the feasibility of detecting biological aerosols with passive FTIR sensors. PMID:12952336

  5. Mid-infrared imaging Fourier transform spectrometry for high power fiber laser irradiated fiberglass composites

    NASA Astrophysics Data System (ADS)

    Acosta, R. I.; Gross, K. C.; Perram, G. P.

    2012-03-01

    New measurement techniques to study continuous wave (CW) laser-material interactions are emerging with the ability to monitor the evolving, spatial distribution of the state of the surface-gas boundary layer. A qualitative analysis of gas phase combustion plumes above the surface of laser irradiated fiberglass composites is developed from fast framing hyperspectral imagery observations. An imaging Fourier Transform Spectrometer (IFTS) operating in the mid-infrared (MWIR) with high framing rate has recently been developed at the Air Force Institute of Technology (AFIT) in collaboration with Telops Inc. A 320 x 256 indium antimonide (InSb) focal plane array with spectral response from 1.5 - 5.5 μm is mated with a Michelson interferometer to achieve spectral resolutions as high as 0.25 cm-1. The very fast 16- tap InSb array frames at 1.9 kHz for the full 320 x 256 frame size. The single pixel field of view of 0.3 mrad provides a spatial resolution of 1 mm at the minimum focal distance of 3 m. Painted and unpainted fiberglass composites are irradiated with a 1064 nm CW Nd:YAG laser for 60 s at 100 W in air at atmospheric pressure. Selective emission in the region of 2100 - 3200 cm-1 is readily evident and is used to develop a time-dependent spatial map of both temperature and plume constituents. The time evolution of gas phase combustion products such as CO and CO2 molecules are monitored, with a spectral resolution of 2 cm-1. High-speed imagery is obtained using a low-pass filter for the interferograms, illustrating significant turbulent behavior during laser irradiation. Spatial brightness temperature maps exceed 600 K. Spatial variation in the ratio of [CO2]/[CO] indicates an interplay between heterogeneous and homogeneous kinetics.

  6. Analysis of aircraft exhausts with Fourier-transform infrared emission spectroscopy.

    PubMed

    Heland, J; Schäfer, K

    1997-07-20

    Because of the worldwide growth in air traffic and its increasing effects on the atmospheric environment, it is necessary to quantify the direct aircraft emissions at all altitudes. In this study Fourier-transform infrared emission spectroscopy as a remote-sensing multi-component-analyzing technique for aircraft exhausts was investigated at ground level with a double pendulum interferometer and a line-by-line computer algorithm that was applied to a multilayer radiative transfer problem. Initial measurements were made to specify the spectral windows for traceable compounds, to test the sensitivity of the system, and to develop calibration and continuum handling procedures. To obtain information about the radial temperature and concentration profiles, we developed an algorithm for the analysis of an axial-symmetric multilayered plume by use of the CO(2) hot band at approximately 2400 cm(-1). Measurements were made with several in-service engines. Effects that were due to engine aging were detected but have to be analyzed systematically in the near future. Validation measurements were carried out with a conventional propane gas burner to compare the results with those obtained with standard measurement equipment. These measurements showed good agreement to within +/-20% for the CO and NO(x) results. The overall accuracy of the system was found to be +/-30%. The detection limits of the system for a typical engine plume (380 degrees C, ? = 50 cm) are below 0.1% for CO(2), ~0.7% for H(2)O, ~20 ppmv (parts per million by volume) for CO, and ~90 ppmv for NO. PMID:18259296

  7. Determination of urea, glucose, and phosphate in dialysate with Fourier transform infrared spectroscopy.

    PubMed

    Jensen, Peter Snoer; Bak, Jimmy; Ladefoged, Søren; Andersson-Engels, Stefan

    2004-03-01

    Individual control and quantification of phosphate removal is desirable in dialysis treatment. Currently, no on-line method exists to quantify phosphate removal. We demonstrate that a multivariate calibration model based on infrared transmission spectra is capable of predicting phosphate, urea, and glucose concentrations at clinically relevant levels. The on-line monitoring of these components by infrared spectroscopy is therefore feasible.

  8. Screening for subclinical ketosis in dairy cattle by Fourier transform infrared spectrometry.

    PubMed

    de Roos, A P W; van den Bijgaart, H J C M; Hørlyk, J; de Jong, G

    2007-04-01

    Subclinical ketosis is a metabolic disorder in high-producing dairy cattle that can be detected by ketone bodies in milk: acetone (Ac), acetoacetate (AcAc), and beta-hydroxybutyrate (BHBA). Fourier transform infrared (FTIR) spectrometry is to a growing extent used for determination of milk constituents in milk recording, but as yet there is no calibration for ketone bodies available. The objective of this study was therefore to build a calibration for the MilkoScan FT6000 (FOSS Analytical A/S, Hillerød, Denmark) for Ac, AcAc, and BHBA and to evaluate the FTIR predictions for detection of subclinical ketosis. From 217 herds, 1,080 milk samples were taken from fresh multiparous dairy cows. The Ac, AcAc, and BHBA concentrations were determined by chemical methods using segmented flow analysis. Because of its low concentration, AcAc seemed to be hardly detectable and was therefore not considered further. The correlation between the chemical method results of Ac and BHBA was 0.82, indicating that both ketone bodies were elevated in milk during subclinical ketosis. In wk 1 postpartum, however, most samples with a high Ac concentration did not have a high BHBA concentration, whereas after wk 5 postpartum most samples with a high BHBA concentration did not have a high Ac concentration. For Ac and BHBA, the correlation coefficients between the FTIR predictions and the chemical results were around 0.80 with standard error of cross validation values of 0.184 and 0.064 mM for Ac and BHBA, respectively. Using thresholds of 0.15 mM for Ac and 0.10 mM for BHBA, high values for Ac or BHBA were detected with a sensitivity of 69 to 70%, a specificity of 95%, with 25 to 27% false positives and 6 to 7% false negatives. It is argued that FTIR predictions for Ac and BHBA are valuable for screening cows on subclinical ketosis, especially when used in combination with other indicators, and can serve in the evaluation of the herd health status with respect to subclinical ketosis.

  9. Fourier transform far infrared spectrum of CD 3OD: detailed analysis in the torsional ground state

    NASA Astrophysics Data System (ADS)

    Mukhopadhyay, Indranath; Duan, Yun-Bo; Klee, Stefan

    2004-06-01

    High resolution Fourier transform (FT) far infrared (FIR) spectra of CD 3OD isotopomer of methanol have been measured in the range 20-350 cm -1 at a resolution of 0.0017 cm -1 using a Bruker spectrometer. The spectra were recorded in various runs at pressure in the range of 0.2-0.8 mbar both at room temperature and at -60 °C. The spectra show complicated splitting due to strong torsional-rotational interactions in the molecule. Detailed assignments have been achieved mainly for the torsional ground state levels. The assigned transition wavenumbers along with the previously known microwave (MW) [J. Chem. Phys. 23 (1955) 1195; J. Chem. Phys. 56 (1972) 5887; Spectrochim. Acta A 54 (1998) 1375], and recently measured millimeter-wave (MMW) lines [I. Mukhopadhyay, R.A.H. Butler, F.C. DeLucia, E. Herbst, in preparation], were fit to an eighth order Hamiltonian [J. Chem. Phys. 104 (1996) 3914; J. Chem. Phys. 110 (1999) 927; J. Mol. Spectrosc. 193 (1999) 418; Chem. Phys. 263 (2001) 263; Chem. Phys. 257 (2000) 91; Chem. Phys. 280 (2002) 119; Chem. Phys. (2003) in press] with 62 varied parameters. The data set consisted of a total of 3211 transitions with 2959 FIR transitions from the ground torsional state with rotational angular momentum K ranging from 0 to 19 and J ranging from 0 to 45, and 237 MW and MMW transitions. The fit converged with a standard deviation of 0.0007 cm -1 for the FIR component of the data and the standard deviation for the MW and MMW transitions was 560 kHz. The standard deviation for the FIR lines is well compared with the estimated experimental accuracy of 0.0002 cm -1 for clean unblended lines. Here we report the actual measured wavenumbers with their assignments, some of these were not included in the fit. The complete data set fitted is not included here for the sake of economy of space but can be obtained from IM.

  10. Near-infrared Fourier-transform and millimeterwave spectra of the BiS radical

    NASA Astrophysics Data System (ADS)

    Izumi, K.; Cohen, E. A.; Setzer, K. D.; Fink, E. H.; Kawaguchi, K.

    2008-12-01

    This paper reports the 6400-7400 cm -1 Fourier-transform (FT) near-infrared (NIR) emission spectrum of the BiS X22Π 3/2 → X12Π 1/2 fine structure bands as well as the millimeterwave rotational spectrum of the X12Π 1/2 state. For the FTNIR observations, BiS was produced by reaction of bismuth with sulfur vapor and excited by energy transfer from metastable oxygen, O 2( a1Δ g), in a fast-flow system. As was the case for BiO [O. Shestakov, R. Breidohr, H. Demes, K.D. Setzer, E.H. Fink, J. Mol. Spectrosc. 190 (1998) 28-77], the 0.5 cm -1resolution spectrum revealed a number of strong bands in the Δv = 0 and ±1 sequences which showed perturbed band spacings, band shapes, and intensities due to avoided crossing of the X22Π 3/2 and A14Π 3/2 potential curves for v' ⩾ 4 of X22Π 3/2. The millimeterwave rotational spectrum of BiS in its X12Π 1/2 state was observed when BiS was produced in a high-temperature oven by a discharge in a mixture of Bi vapor and CS 2. The signal to noise ratio was markedly improved by using a White-type multipath cell. Ninety seven features from J' = 23.5 to J' = 41.5 were measured between 150 and 300 GHz. Analysis of the 0.5 cm -1 resolution FT spectrum yielded the fine structure splitting and vibrational constants of the states. A simultaneous analysis of millimeterwave and a 0.005 cm -1 FT spectrum of the 0-0 band of the NIR system was carried out to give precise rotational, fine, and hyperfine constants for the X12Π 1/2 and X22Π 3/2 states. The results are consistent with those reported earlier for BiO and indicate only a slight decrease in the unpaired electron density in the 6p(π ∗) orbital on the Bi atom.

  11. Fourier transform infrared spectroscopy as a method to study lipid accumulation in oleaginous yeasts

    PubMed Central

    2014-01-01

    Background Oleaginous microorganisms, such as different yeast and algal species, can represent a sustainable alternative to plant oil for the production of biodiesel. They can accumulate fatty acids (FA) up to 70% of their dry weight with a predominance of (mono)unsaturated species, similarly to what plants do, but differently from animals. In addition, their growth is not in competition either with food, feed crops, or with agricultural land. Despite these advantages, the exploitation of the single cell oil system is still at an early developmental stage. Cultivation mode and conditions, as well as lipid extraction technologies, represent the main limitations. The monitoring of lipid accumulation in oleaginous microorganisms is consequently crucial to develop and validate new approaches, but at present the majority of the available techniques is time consuming, invasive and, when relying on lipid extraction, can be affected by FA degradation. Results In this work the fatty acid accumulation of the oleaginous yeasts Cryptococcus curvatus and Rhodosporidium toruloides and of the non-oleaginous yeast Saccharomyces cerevisiae (as a negative control) was monitored in situ by Fourier Transform Infrared Spectroscopy (FTIR). Indeed, this spectroscopic tool can provide complementary information to those obtained by classical techniques, such as microscopy, flow cytometry and gas chromatography. As shown in this work, through the analysis of the absorption spectra of intact oleaginous microorganisms it is possible not only to monitor the progression of FA accumulation but also to identify the most represented classes of the produced lipids. Conclusions Here we propose FTIR microspectroscopy - supported by multivariate analysis - as a fast, reliable and non invasive method to monitor and analyze FA accumulation in intact oleaginous yeasts. The results obtained by the FTIR approach were in agreement with those obtained by the other classical methods like flow cytometry and

  12. Understanding Microbe-Mineral Reactions Using Synchrotron Radiation Fourier Transform Infrared Spectromicroscopy

    NASA Astrophysics Data System (ADS)

    Kauffman, M. E.; Lehman, R. M.; Martin, M. C.; Bauer, W. F.

    2002-12-01

    Microorganisms are able to alter their surrounding microenvironment to an extent not predicted by the thermodynamics of the macro-environment chemistry. Microbially induced environmental alterations include weathering, biomineralization and mobilization or immobilization of authegenic metals or contaminants. Microbial colonization of surfaces, followed by biofilm formation, are the first steps in alteration processes. With the exception of iron oxides and iron-reducing bacteria, the fundamentals of how microbes react with various mineral surfaces is not well understood. Synchrotron radiation Fourier transform infrared spectromicroscopy (SR-FTIR) is a non-destructive analytical technique capable of probing, in situ, the microbe-mineral interface. The SR-FTIR beamline 1.4.3, at the Advanced Light Source, Berkeley, CA, has a diffraction-limited spatial resolution of 10 um, is 2-3 orders of magnitude brighter than traditional FTIR, and is not harmful to living samples. Aliquots of pure cultures of Burkholderia cepacia G4 were deposited on four individual mineral surfaces (plagioclase, ilmenite, augite and olivine) and spectra were collected within 20-40 min. Reference spectra were collected from the same pure cultures deposited on gold-coated glass slides. Additionally, reference spectra were collected of commercially available biomolecules deposited on the four individual mineral specimens. The spectra of the bacterial cells on gold and the spectra of the separate biomolecules contained all the relevant peaks documented in the literature. However, the spectra collected from the microbe-mineral interfaces were markedly different from the reference spectra and varied between the four mineral surfaces. Bacterial cells in contact with plagioclase exhibited predominantly absorption bands associated with phosphate groups, while the spectra of olivine and bacterial cells were limited to absorption bands associated with bacterial proteins. Spectra of the same bacterial cells

  13. Fourier transform infrared imaging analysis in discrimination studies of squamous cell carcinoma.

    PubMed

    Pallua, J D; Pezzei, C; Zelger, B; Schaefer, G; Bittner, L K; Huck-Pezzei, V A; Schoenbichler, S A; Hahn, H; Kloss-Brandstaetter, A; Kloss, F; Bonn, G K; Huck, C W

    2012-09-01

    Oral squamous cell carcinoma (OSCC) of the oral cavity and oropharynx represents more than 95% of all malignant neoplasms in the oral cavity. Histomorphological evaluation of this cancer type is invasive and remains a time consuming and subjective technique. Therefore, novel approaches for histological recognition are necessary to identify malignancy at an early stage. Fourier transform infrared (FTIR) imaging has become an essential tool for the detection and characterization of the molecular components of biological processes, such as those responsible for the dynamic properties of tumor progression. FTIR imaging is a modern analytical technique enabling molecular imaging of a complex biological sample and is based on the absorption of IR radiation by vibrational transitions in covalent bonds. One major advantage of this technique is the acquisition of local molecular expression profiles, while maintaining the topographic integrity of the tissue and avoiding time-consuming extraction, purification, and separation steps. With this imaging technique, it is possible to obtain unique images of the spatial distribution of proteins, lipids, carbohydrates, cholesterols, nucleic acids, phospholipids, and small molecules with high spatial resolution. Analysis and visualization of FTIR imaging datasets are challenging and the use of chemometric tools is crucial in order to take advantage of the full measurement. Therefore, methodologies for this task based on the novel developed algorithm for multivariate image analysis (MIA) are often necessary. In the present study, FTIR imaging and data analysis methods were combined to optimize the tissue measurement mode after deparaffinization and subsequent data evaluation (univariate analysis and MIAs). We demonstrate that it is possible to collect excellent IR spectra from formalin-fixed paraffin-embedded (FFPE) tissue microarrays (TMAs) of OSCC tissue sections employing an optimised analytical protocol. The correlation of FTIR

  14. Characterization of biomass burning: Fourier transform infrared analysis of wood and vegetation combustion products

    NASA Astrophysics Data System (ADS)

    Padilla, Diomaris

    The Fourier transform infrared examination of the combustion products of a selection of forest materials has been undertaken in order to guide future detection of biomass burning using satellite remote sensing. Combustion of conifer Pinus strobus (white pine) and deciduous Prunus serotina (cherry), Acer rubrum (red maple), Friglans nigra (walnut), Fraxinus americana (ash), Betula papyrifera (birch), Querus alba (white oak) and Querus rubra (red oak) lumber, in a Meeker burner flame at temperatures of 400 to 900 degrees Fahrenheit produces a broad and relatively flat signal with a few distinct peaks throughout the wavelength spectra (400 to 4000 cm-1). The distinct bands located near wavelengths of 400-700, 1500-1700, 2200-2400 and 3300-3600 cm-1 vary in intensity with an average difference between the highest and lowest absorbing species of 47 percent. Spectral band differences of 10 percent are within the range of modern satellite spectrometers, and support the argument that band differences can be used to discriminate between various types of vegetation. A similar examination of soot and smoke derived from the leaves and branches of the conifer Pinus strobus and deciduous Querus alba (white oak), Querus rubra (red oak), Liquidambar styraciflua (sweetgum), Acer rubrum (maple) and Tilea americana (American basswood) at combustion temperatures of 400 to 900 degrees Fahrenheit produce a similar broad spectrum with a shift in peak location occurring in peaks below the 1700 cm-1 wavelength. The new peaks occur near wavelengths of 1438-1444, 875 and 713 cm-1. This noted shift in wavelength location may be indicative of a fingerprint region for green woods distinguishable from lumber through characteristic biomass suites. Temperature variations during burning show that the spectra of low temperature smoldered aerosols, occurring near 400 to 450 degrees Fahrenheit, may be distinguished from higher temperature soot aerosols that occur above 600 degrees Fahrenheit. A

  15. Trace Gas Emissions From Global Biomass Burning Measured by Fourier Transform Infrared (FTIR) Spectroscopy

    NASA Astrophysics Data System (ADS)

    Bertschi, I.; Yokelson, R. J.; Christian, T. J.; Field, R. J.; Ward, D. E.; Hao, W.

    2001-05-01

    Biomass burning is an important source of CO(2), CO, CH(4), NO(x), non-methane volatile organic compounds (VOCs), oxygenated volatile organic compounds (OVOCs), and particles in the global atmosphere. In recent field experiments we have used airborne Fourier transform infrared (AFTIR) spectroscopy in Africa, North Carolina, and Alaska. These in-situ measurements have included observations of the rate of ozone and organic acid production, NH(3) losses, and cloud processing in down-wind plumes. In addition, we used AFTIR measurements to characterize the immense mixed haze layers prevalent during the southern Africa dry season and probed the chemistry of two ship plumes off the Namibian coastline. Our airborne measurements of biomass fire emissions were supplemented by ground-based open-path FTIR measurements of the emissions from domestic fuel production and use in African villages and of the post-convection smoldering emissions from African fires. Our ground and airborne measurements both include a suite of important compounds produced from biomass burning sources and from the photochemistry of slightly aged smoke plumes. This suite of compounds includes; O(3), CO(2), CO, CH(4), non-methane VOCs (C(2)H(2), C(2)H(4), C(2)H(6), C(3)H(6)), NO(x), HCN, NH(3), and OVOCs (CH(2)O, HCOOH, CH(3)OH, CH(3)COOH, HOCH(2)COOH, C(6)H(6)O, C(4)H(4)O) that are important HO(x) (OH and HO(2)) precursors. Recently, African and Indonesian fuels were burned in a joint laboratory experiment with the Max-Planck Institute of Chemistry that featured our open-path FTIR and their proton-transfer mass spectrometer (PTR-MS). The research described above consistently shows that biomass fires emit significant concentrations of OVOCs at levels much higher than previously thought. Our laboratory and field findings have been incorporated in a photochemical model that shows the OVOCs in smoke have significant effects on ozone production, HO(x) concentrations, H(2)O(2) production, NO(x) lifetime, and

  16. [Detection of Syrup Adulterants in Prepackaged Pure Pineapple Juice by Fourier-Transform Infrared Spectroscopy and Chemometric Analysis].

    PubMed

    Zhou, Mi; Ke, Jian; Li, Bao-li; Tang, Cui-e; Tan, Jun; Liu, Rui; Wang, Hong; Li, Tao; Zhou, Sheng-yin

    2015-10-01

    This study was performed to establish a method that can quickly and accurately identify adulterated syrup in the pure pineapple juice. A attenuated total internal refraction-fourier transform infrared spectroscopy was used to collect the range of 900 -1 500 cm(-1) infrared spectra of 234 samples pure pineapple juice and adulterated syrup by beet syrup, rice syrup and cassava syrup. By using linear discriminant analysis and support vector machine for the identification model, comparing the full spectral and selected wavelengths based on principal component analysis loading plots of the two models to identify adulteration. Studies showed that the correct rate of validation set by linear discriminant analysis and support vector machine model on full spectral were both higher than 88%, variables were significantly reduced from 312 to 8 after selecting the eight characteristic wavelengths, the correct rate of validation set by linear discriminant analysis model was up to 96.15% and support vector machine was increase to 94.87%. The results demonstrated that the model built using a attenuated total internal refraction-fourier transform infrared spectroscopy in combination with chemometric methods after selected characteristic wavelengths could be used for the identification of the adulterated syrup in the pure pineapple juice. PMID:26904809

  17. Detection of albumin unfolding preceding proteolysis using Fourier transform infrared spectroscopy and chemometric data analysis.

    PubMed

    Domínguez-Vidal, Ana; Saenz-Navajas, María P; Ayora-Cañada, María José; Lendl, Bernhard

    2006-05-15

    The hydrolysis of bovine serum albumin with protease K at 60 degrees C has been studied by means of infrared spectroscopy. Two-dimensional correlation spectroscopy (2DCoS) has been used to study spectral changes in the reaction. The use of the multivariate curve resolution-alternating least-squares method applied to infrared measurements allowed the recovery of pure infrared spectra and concentration profiles of the different species involved in the reaction. Special attention was paid to the careful inspection of residuals again using 2DCoS. In this way, a heat-induced unfolding step previous to protein hydrolysis was identified. The infrared spectra of the intermediate species showed a more disordered structure than native albumin, the decrease in alpha-helix conformation being especially noticeable. The formation of beta-sheet aggregates due to heating was detected too.

  18. The mechanical properties and molecular dynamics of plant cell wall polysaccharides studied by Fourier-transform infrared spectroscopy.

    PubMed

    Wilson, R H; Smith, A C; Kacuráková, M; Saunders, P K; Wellner, N; Waldron, K W

    2000-09-01

    Polarized one- and two-dimensional infrared spectra were obtained from the epidermis of onion (Allium cepa) under hydrated and mechanically stressed conditions. By Fourier-transform infrared microspectroscopy, the orientation of macromolecules in single cell walls was determined. Cellulose and pectin exhibited little orientation in native epidermal cell walls, but when a mechanical stress was placed on the tissue these molecules showed distinct reorientation as the cells were elongated. When the stress was removed the tissue recovered slightly, but a relatively large plastic deformation remained. The plastic deformation was confirmed in microscopic images by retention of some elongation of cells within the tissue and by residual molecular orientation in the infrared spectra of the cell wall. Two-dimensional infrared spectroscopy was used to determine the nature of the interaction between the polysaccharide networks during deformation. The results provide evidence that cellulose and xyloglucan associate while pectin creates an independent network that exhibits different reorientation rates in the wet onion cell walls. The pectin chains respond faster to oscillation than the more rigid cellulose.

  19. Characterization of a water-dispersible metal protective coating with Fourier transform infrared spectroscopy, modulated differential scanning calorimetry, and ellipsometry.

    PubMed

    Boyatzis, Stamatis C; Douvas, Antonios M; Argyropoulos, Vassilike; Siatou, Amalia; Vlachopoulou, Marilena

    2012-05-01

    An ethylene-methacrylic acid copolymer, formulated by BASF as a waterborne suspension of its alkylammonium salt and used, among other applications, in art conservation as a temporary protective coating was characterized using Fourier transform infrared (FT-IR) spectroscopy aided by modulated differential scanning calorimetry (MDSC) and ellipsometry. The thermal conversion of thin copolymer films from the freshly applied state, where carboxylic acid and carboxylate ion functional groups co-exist, to a purely acidic working state was spectroscopically followed. Transmission mid-infrared data of the working state showed a 1 : 12 ratio of methacrylic acid towards ethylene units. The glass transition temperature (T(g)) in the same state was found at 45 °C. Copolymer films spin-coated on mechanically polished bronze and iron coupons were characterized with transflection infrared spectroscopy and compared to corresponding transmission mid-infrared spectra of copolymer films spin-coated on silicon wafers. In the case of bronze coupons, evidence for interaction of the carboxylate ion with the copper substrate was obtained. The chemical structure and the thermal behavior of the coating, as well as some implications on its protective capability towards iron and copper alloys, is discussed as this material has received considerable attention in the field of metal conservation and coatings.

  20. Interactions among lactose, β-lactoglobulin and starch in co-lyophilized mixtures as determined by Fourier Transform Infrared Spectroscopy.

    PubMed

    Hajihashemi, Zohreh; Nasirpour, Ali; Scher, Joël; Desobry, Stéphane

    2014-11-01

    Processing and storage change food powders containing a large quantity of lactose due to lactose crystallization and interactions among components. Model food systems were prepared by co-lyophilization of lactose, β-lactoglobulin (BLG), and gelatinized starch. A mixture design was used to define the percentage of each mixture component to simulate a wide range of food powders. Interactions among lactose, BLG and starch were studied using Fourier Transform Infrared (FT-IR) at different relative humidities (RH), before and after 3 months storage. Results showed the presence of hydrogen bonds among these components. Moreover, interactions or formation of hydrogen bonds among lactose, starch and BLG preserved BLG against freezing and freeze-drying shocks. Lactose crystallization could be identified by comparing infrared spectra of amorphous and crystallized lactose at O - H and C - H stretching vibration bands. PMID:26396334

  1. Assessment of nitrous oxide emission from cement plants: real data measured with both Fourier transform infrared and nondispersive infrared techniques.

    PubMed

    Mosca, Silvia; Benedetti, Paolo; Guerriero, Ettore; Rotatori, Mauro

    2014-11-01

    Nitrous oxide (N2O) is the third most important greenhouse gas after carbon dioxide and methane, and contributes about 6% to the greenhouse effect. Nitrous oxide is a minor component of the atmosphere, and it is a thousand times less than carbon dioxide (CO2). Nevertheless, it is much more potent than CO2 and methane, owing to its long stay in the atmosphere of approximately 120 yr and the high global warmingpotential (GWP) of298 times that of CO2. Although greenhouse gases are natural in the atmosphere, human activities have changed the atmospheric concentrations. Most of the values of emission of nitrous oxide are still obtained by means ofemission factors and not actually measured; the lack ofreal data may result in an underestimation ofcurrent emissions. The emission factors used for the calculation of N2O can be obtained from the "Guidelines for the implementation of the national inventory of emissions" of the Intergovernmental Panel on Climate Change, which refer to all nations for the realization of their inventory. This study will present real data, measured in several Italian cement plants with different characteristics. The work also shows a comparison between N2O concentration measured with in situ-Fourier transform IR (FTIR) and the reference method EN ISO 21258 based on nondispersive IR (NDIR), in order to investigate the interfering compounds in the measurement with NDIR.

  2. Assessment of nitrous oxide emission from cement plants: real data measured with both Fourier transform infrared and nondispersive infrared techniques.

    PubMed

    Mosca, Silvia; Benedetti, Paolo; Guerriero, Ettore; Rotatori, Mauro

    2014-11-01

    Nitrous oxide (N2O) is the third most important greenhouse gas after carbon dioxide and methane, and contributes about 6% to the greenhouse effect. Nitrous oxide is a minor component of the atmosphere, and it is a thousand times less than carbon dioxide (CO2). Nevertheless, it is much more potent than CO2 and methane, owing to its long stay in the atmosphere of approximately 120 yr and the high global warmingpotential (GWP) of298 times that of CO2. Although greenhouse gases are natural in the atmosphere, human activities have changed the atmospheric concentrations. Most of the values of emission of nitrous oxide are still obtained by means ofemission factors and not actually measured; the lack ofreal data may result in an underestimation ofcurrent emissions. The emission factors used for the calculation of N2O can be obtained from the "Guidelines for the implementation of the national inventory of emissions" of the Intergovernmental Panel on Climate Change, which refer to all nations for the realization of their inventory. This study will present real data, measured in several Italian cement plants with different characteristics. The work also shows a comparison between N2O concentration measured with in situ-Fourier transform IR (FTIR) and the reference method EN ISO 21258 based on nondispersive IR (NDIR), in order to investigate the interfering compounds in the measurement with NDIR. PMID:25509548

  3. A near-infrared Fourier transform Raman spectroscopy of epidermal keratinocytes: changes in the protein?DNA structure following malignant transformation

    NASA Astrophysics Data System (ADS)

    Gao, Xiaoling; Butler, Ian S.; Kremer, Richard

    2005-01-01

    We report here the use of near-infrared (NIR) Fourier transform (FT) Raman spectroscopy to analyze normal human epidermal keratinocytes prior to and following malignant transformation. Our analysis indicates specific Raman spectral differences between immortalized (HPK1A) and malignant ras transformed (HPK1A- ras) cells. In addition, striking spectral differences are seen in the DNA isolated from these cells and particularly in the 843/810 cm -1 ratio with values of 1.6 ± 0.13 in HPK1A cells and 0.68 ± 0.09 in HPK1A- ras cells (mean ± S.D., n = 12, P < 0.001) indicating specific alterations in the backbone conformation markers following malignant transformation. Subsequently, we analysed the effect of a strong inhibitor of keratinocyte growth, the Vitamin D analog EB1089, on the Raman spectra of intact cells and on the 843/810 cm -1 ratio in the DNA isolated from both cell lines. Specific changes were observed in intact cells in the 1300-750 cm -1 region. Furthermore, the 843/810cm -1 ratio of isolated DNA from HPK1A cells was not affected by EB1089 but significantly increased in DNA isolated from HPK1A-ras cells so much that it became closer to the value observed for HPK1A cells (1.07 ± 0.10). Our data suggest that Raman analysis of DNA and in particular the 843/810cm -1 ratio can provide useful indices of malignant transformation and efficacy of anticancer agents.

  4. Far-infrared sensor for cirrus (FIRSC): an aircraft-based Fourier-transform spectrometer to measure cloud radiance.

    PubMed

    Vanek, M D; Nolt, I G; Tappan, N D; Ade, P A; Gannaway, F C; Hamilton, P A; Lee, C; Davis, J E; Predko, S

    2001-05-01

    We describe an aircraft-based Fourier-transform spectrometer (FTS) designed to measure the Earth outgoing radiance spectrum in the far-infrared-submillimeter spectral range. The instrument features include a rapid-scan FTS to obtain high spatial resolution from a moving aircraft platform, a sensitive two-channel detector, and a CCD camera for recording the nadir cloud scene with each scan record. Such measurements demonstrate the sensitivity of Earth radiance to high clouds and provide spectral data for improving techniques for remote sensing and retrieval of atmospheric and cloud properties.

  5. Measurement of ethanol formation in single living cells of Chlamydomonas reinhardtii using synchrotron Fourier Transform Infrared spectromicroscopy

    SciTech Connect

    Goff, Kira L.; Quaroni, Luca; Pedersen, Tor; Wilson, Kenneth E.

    2010-02-03

    We demonstrate the capability of Fourier-Transform Infra-Red (FITR) spectroscopy to detect metabolite formation by the unicellular algae Chlamydomonas reinhardtii in solution. We show that using a synchrotron source in the microscopy configuration provides a sufficient s/n ratio to detect small molecular species accumulating at a single cell, allowing an increased sensitivity relative to measurements of bulk cultures. The formation of small molecular species, including ethanol and at least one carbonyl containing compound, can be detected with a time resolution of the order of one minute.

  6. Analysis of F-Canyon Effluents During the Dissolution Cycle with a Fourier Transform Infrared Spectrometer/Multipath Cell

    SciTech Connect

    Villa, E.

    1999-07-28

    Air samples from F-Canyon effluents were collected at the F-Canyon stack and transported to a laboratory at the Savannah River Technology Center (SRTC) for analysis using a Fourier transform infrared spectrometer in conjunction with a multipath cell. Air samples were collected during the decladding and acid cuts of the dissolution of the irradiated aluminum-cladded slugs. The FTIR analyses of the air samples show the presence of NO2, NO, HNO2, N2O, SF6, and 85Kr during the dissolution cycle. The concentration time profiles of these effluents corresponded with expected release rates from the F-Canyon operations.

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

    SciTech Connect

    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.

  8. Resin characterization in cured graphite fiber reinforced composites using diffuse reflectance-FTIR. [Fourier transform infrared spectroscopy

    NASA Technical Reports Server (NTRS)

    Young, P. R.; Stein, B. A.; Chang, A. C.

    1983-01-01

    The feasibility of using diffuse reflectance in combination with Fourier transform infrared spectroscopy to obtain information on cured graphite fiber reinforced polymeric matrix resin composites was investigated. Several graphite/epoxy, polysulfone, and polyimide composites exposed to thermal or radiation environments were examined. An experimental polyimide-sulfone adhesive tape was also studied during processing. In each case, significant changes in resin molecular structure was observed due to environmental exposure. These changes in molecular structure were correlated with previously observed changes in material properties providing new insights into material behavior.

  9. Near-infrared and fourier transform infrared chemometric methods for the quantification of crystalline tacrolimus from sustained-release amorphous solid dispersion.

    PubMed

    Rahman, Ziyaur; Siddiqui, Akhtar; Bykadi, Srikant; Khan, Mansoor A

    2014-08-01

    The objective of the present research was to study the feasibility of using near-infrared (NIR) and Fourier transform infrared (FTIR)-based chemometric models in quantifying crystalline and amorphous tacrolimus from its sustained-release amorphous solid dispersion (ASD). ASD contained ethyl cellulose, hydroxypropyl methyl cellulose, and lactose monohydrate as carriers, and amorphous form of tacrolimus in it was confirmed by X-ray powder diffraction. Crystalline physical mixture was mixed with ASD in various proportions to prepare sample matrices containing 0%-100% amorphous/crystalline tacrolimus. NIR and FTIR of the samples were recorded, and data were mathematically pretreated using multiple scattering correction, standard normal variate, or Savitzky-Golay before multivariate analysis, partial-least-square regression (PLSR), and principle component regression (PCR). The PLSR models were more accurate than PCR for NIR and FTIR data as indicated by low value of root-mean-squared error of prediction, standard error of prediction and bias, and high value of R(2). Additionally, NIR data-based models were more accurate and precise than FTIR data models. In conclusion, NIR chemometric models provide simple and fast method to quantitate crystalline tacrolimus in the ASD formulation.

  10. Near-infrared and fourier transform infrared chemometric methods for the quantification of crystalline tacrolimus from sustained-release amorphous solid dispersion.

    PubMed

    Rahman, Ziyaur; Siddiqui, Akhtar; Bykadi, Srikant; Khan, Mansoor A

    2014-08-01

    The objective of the present research was to study the feasibility of using near-infrared (NIR) and Fourier transform infrared (FTIR)-based chemometric models in quantifying crystalline and amorphous tacrolimus from its sustained-release amorphous solid dispersion (ASD). ASD contained ethyl cellulose, hydroxypropyl methyl cellulose, and lactose monohydrate as carriers, and amorphous form of tacrolimus in it was confirmed by X-ray powder diffraction. Crystalline physical mixture was mixed with ASD in various proportions to prepare sample matrices containing 0%-100% amorphous/crystalline tacrolimus. NIR and FTIR of the samples were recorded, and data were mathematically pretreated using multiple scattering correction, standard normal variate, or Savitzky-Golay before multivariate analysis, partial-least-square regression (PLSR), and principle component regression (PCR). The PLSR models were more accurate than PCR for NIR and FTIR data as indicated by low value of root-mean-squared error of prediction, standard error of prediction and bias, and high value of R(2). Additionally, NIR data-based models were more accurate and precise than FTIR data models. In conclusion, NIR chemometric models provide simple and fast method to quantitate crystalline tacrolimus in the ASD formulation. PMID:24931728

  11. Fourier transform mid-infrared (MIR) and near-infrared (NIR) spectroscopy for rapid quality assessment of Chinese medicine preparation Honghua Oil.

    PubMed

    Wu, Yan-Wen; Sun, Su-Qin; Zhou, Qun; Leung, Hei-Wun

    2008-02-13

    Honghua Oil (HHO), a traditional Chinese medicine (TCM) oil preparation, is a mixture of several plant essential oils. In this text, the extended ranges of Fourier transform mid-infrared (FT-MIR) and near infrared (FT-NIR) were recorded for 48 commercially available HHOs of different batches from nine manufacturers. The qualitative and quantitative analysis of three marker components, alpha-pinene, methyl salicylate and eugenol, in different HHO products were performed rapidly by the two vibrational spectroscopic methods, i.e. MIR with horizontal attenuated total reflection (HATR) accessory and NIR with direct sampling technique, followed by partial least squares (PLS) regression treatment of the set of spectra obtained. The results indicated that it was successful to identify alpha-pinene, methyl salicylate and eugenol in all of the samples by simple inspection of the MIR-HATR spectra. Both PLS models established with MIR-HATR and NIR spectral data using gas chromatography (GC) peak areas as calibration reference showed a good linear correlation for each of all three target substances in HHO samples. The above spectroscopic techniques may be the promising methods for the rapid quality assessment/quality control (QA/QC) of TCM oil preparations.

  12. Synchrotron radiation-based Fourier-transform infrared spectromicroscopy for characterization of the protein/peptide distribution in single microspheres.

    PubMed

    Wang, Manli; Lu, Xiaolong; Yin, Xianzhen; Tong, Yajun; Peng, Weiwei; Wu, Li; Li, Haiyan; Yang, Yan; Gu, Jingkai; Xiao, Tiqiao; Chen, Min; Zhang, Jiwen

    2015-05-01

    The present study establishes a visualization method for the measurement of the distribution and localization of protein/peptide constituents within a single poly-lactide-co-glycolide (PLGA) microsphere using synchrotron radiation-based Fourier-transform infrared spectromicroscopy (SR-FTIR). The representative infrared wavenumbers specific for protein/peptide (Exenatide) and excipient (PLGA) were identified and chemical maps at the single microsphere level were generated by measuring and plotting the intensity of these specific bands. For quantitative analysis of the distribution within microspheres, Matlab software was used to transform the map file into a 3D matrix and the matrix values specific for the drug and excipient were extracted. Comparison of the normalized SR-FTIR maps of PLGA and Exenatide indicated that PLGA was uniformly distributed, while Exenatide was relatively non-uniformly distributed in the microspheres. In conclusion, SR-FTIR is a rapid, nondestructive and sensitive detection technology to provide the distribution of chemical constituents and functional groups in microparticles and microspheres. PMID:26579456

  13. Synchrotron radiation-based Fourier-transform infrared spectromicroscopy for characterization of the protein/peptide distribution in single microspheres

    PubMed Central

    Wang, Manli; Lu, Xiaolong; Yin, Xianzhen; Tong, Yajun; Peng, Weiwei; Wu, Li; Li, Haiyan; Yang, Yan; Gu, Jingkai; Xiao, Tiqiao; Chen, Min; Zhang, Jiwen

    2015-01-01

    The present study establishes a visualization method for the measurement of the distribution and localization of protein/peptide constituents within a single poly-lactide-co-glycolide (PLGA) microsphere using synchrotron radiation–based Fourier-transform infrared spectromicroscopy (SR-FTIR). The representative infrared wavenumbers specific for protein/peptide (Exenatide) and excipient (PLGA) were identified and chemical maps at the single microsphere level were generated by measuring and plotting the intensity of these specific bands. For quantitative analysis of the distribution within microspheres, Matlab software was used to transform the map file into a 3D matrix and the matrix values specific for the drug and excipient were extracted. Comparison of the normalized SR-FTIR maps of PLGA and Exenatide indicated that PLGA was uniformly distributed, while Exenatide was relatively non-uniformly distributed in the microspheres. In conclusion, SR-FTIR is a rapid, nondestructive and sensitive detection technology to provide the distribution of chemical constituents and functional groups in microparticles and microspheres. PMID:26579456

  14. Monitoring light-induced structural changes of Channelrhodopsin-2 by UV-visible and Fourier transform infrared spectroscopy.

    PubMed

    Ritter, Eglof; Stehfest, Katja; Berndt, Andre; Hegemann, Peter; Bartl, Franz J

    2008-12-12

    Channelrhodopsin-2 (ChR2) is a microbial type rhodopsin and a light-gated cation channel that controls phototaxis in Chlamydomonas. We expressed ChR2 in COS-cells, purified it, and subsequently investigated this unusual photoreceptor by flash photolysis and UV-visible and Fourier transform infrared difference spectroscopy. Several transient photoproducts of the wild type ChR2 were identified, and their kinetics and molecular properties were compared with those of the ChR2 mutant E90Q. Based on the spectroscopic data we developed a model of the photocycle comprising six distinguishable intermediates. This photocycle shows similarities to the photocycle of the ChR2-related Channelrhodopsin of Volvox but also displays significant differences. We show that molecular changes include retinal isomerization, changes in hydrogen bonding of carboxylic acids, and large alterations of the protein backbone structure. These alterations are stronger than those observed in the photocycle of other microbial rhodopsins like bacteriorhodopsin and are related to those occurring in animal rhodopsins. UV-visible and Fourier transform infrared difference spectroscopy revealed two late intermediates with different time constants of tau = 6 and 40 s that exist during the recovery of the dark state. The carboxylic side chain of Glu(90) is involved in the slow transition. The molecular changes during the ChR2 photocycle are discussed with respect to other members of the rhodopsin family. PMID:18927082

  15. [Identification of different Citrus sinensis (L.) Osbeck trees varieties using Fourier transform infrared spectroscopy and hierarchical cluster analysis].

    PubMed

    Yi, Shi-Lai; Deng, Lie; He, Shao-Lan; Shi, You-Ming; Zheng, Yong-Qiang; Lu, Qiang; Xie, Rang-Jin; Wei, Xian-Guoi; Li, Song-Wei; Jian, Shui-Xian

    2012-11-01

    Researched on diversity of the spring leaf samples of seven different Citrus sinensis (L.) Osbeck varieties by Fourier transform infrared (FTIR) spectroscopy technology, the results showed that the Fourier transform infrared spectra of seven varieties leaves was composited by the absorption band of cellulose and polysaccharide mainly, the wave number of characteristics absorption peaks were similar at their FTIR spectra. However, there were some differences in shape of peaks and relatively absorption intensity. The conspicuous difference was presented at the region between 1 500 and 700 cm(-1) by second derivative spectra. Through the hierarchical cluster analysis (HCA) of second derivative spectra between 1 500 and 700 cm(-1), the results showed that the clustering of the different varieties of Citrus sinensis (L.) Osbeck varieties was classification according to genetic relationship. The results showed that FTIR spectroscopy combined with hierarchical cluster analysis could be used to identify and classify of citrus varieties rapidly, it was an extension method to study on early leaves of varieties orange seedlings.

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

    PubMed

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

    2015-01-01

    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.

  17. Analysis of the Spectral Characteristics of Pure Moxa Stick Burning by Hyperspectral Imaging and Fourier Transform Infrared Spectroscopy

    PubMed Central

    Li, Yin-long

    2016-01-01

    The objective of this study was to investigate the spectra characteristics (SC) at wavelengths of 400~1000 nm and 2.5~15.5 μm of pure moxa stick (MS) during its 25-minute burning process using new spectral imaging techniques. Spectral images were collected for the burning pure MS at 5, 10, 15, 20, and 25 min using hyperspectral imaging (HSI) and Fourier transform infrared spectroscopy (FTIR) for the first time. The results showed that, at wavelengths of 400~1000 nm, the spectral range of the cross section of MS burning was 750~980 nm; the peak position was 860 nm. At wavelengths of 2.5~15.5 μm, the spectral range of the cross section of MS burning was 3.0~4.0 μm; the peak position was approximately 3.5 μm. The radiation spectra of MS burning include litter red and amount of infrared (but mainly near infrared) wavelengths. The temperature, blood perfusion, and oxygen saturation increase of Shenshu (BL23) after moxibustion radiation were observed too. According to mechanism of photobiological effects and moxibustion biological effects, it was inferred that moxibustion effects should be linked with moxibustion SC. This study provided new data and means for physical properties of moxibustion research. PMID:27721889

  18. Novel high-temperature and pressure-compatible ultrasonic levitator apparatus coupled to Raman and Fourier transform infrared spectrometers.

    PubMed

    Brotton, Stephen J; Kaiser, Ralf I

    2013-05-01

    We describe an original apparatus comprising of an acoustic levitator enclosed within a pressure-compatible process chamber. To characterize any chemical and physical modifications of the levitated particle, the chamber is interfaced to complimentary, high-sensitivity Raman (4390-170 cm(-1)), and Fourier transform infrared (FTIR) (10,000-500 cm(-1)) spectroscopic probes. The temperature of the levitated particle can be accurately controlled by heating using a carbon dioxide laser emitting at 10.6 μm. The advantages of levitating a small particle combined with the two spectroscopic probes, process chamber, and infrared laser heating makes novel experiments possible relevant to the fields of, for example, planetary science, astrobiology, and combustion chemistry. We demonstrate that this apparatus is well suited to study the dehydration of a variety of particles including minerals and biological samples; and offers the possibility of investigating combustion processes involving micrometer-sized particles such as graphite. Furthermore, we show that the FTIR spectrometer enables the study of chemical reactions on the surfaces of porous samples and scientifically and technologically relevant, micrometer-thick levitated sheets. The FTIR spectrometer can also be used to investigate non-resonant and resonant scattering from small, irregularly-shaped particles across the mid-infrared range from 2.5 μm to 25 μm, which is relevant to scattering from interplanetary dust and biological, micrometer-sized samples but cannot be accurately modelled using Mie theory. PMID:23742596

  19. Tests of various colorants for application of a Fourier transform infrared imaging system to deciphering obliterated writings

    NASA Astrophysics Data System (ADS)

    Sugawara, Shigeru

    2015-10-01

    Obliterated writing is writing that has been obscured by different-colored materials. There are obliterated writings that cannot be detected by conventional methods. A method for deciphering such obliterated writings was developed in this study. Mid-infrared spectroscopic imaging in the wavelength range of 2.5-14 μm was used for deciphering because the infrared spectrum differs among different brands of colorants. Obliterated writings were made by pressing information protection stamps onto characters written by 4 kinds of colorants. The samples were tested for deciphering by the Fourier-transform infrared imaging system. Two peak areas of two specific wavenumber regions of each reflectance spectrum were calculated and the ratio of the two values is displayed as a unique gray scale in the spectroscopic image. As a result, the absorption peak at various wavenumbers could be used to decipher obliterated writings that could not be detected by the conventional methods. Ten different parameters for deciphering obliterated writing were found in this study.

  20. Fourier Transform Infrared Spectroscopy to Quantify Collagen and Elastin in an In Vitro Model of Extracellular Matrix Degradation in Aorta

    PubMed Central

    Cheheltani, Rabee; McGoverin, Cushla M.; Rao, Jayashree; Vorp, David A.; Kiani, Mohammad F.; Pleshko, N.

    2014-01-01

    Extracellular matrix (ECM) is a key component and regulator of many biological tissues including aorta. Several aortic pathologies are associated with significant changes in the composition of the matrix, especially in the content, quality and type of aortic structural proteins, collagen and elastin. The purpose of this study was to develop an infrared spectroscopic methodology that is comparable to biochemical assays to quantify collagen and elastin in aorta. Enzymatically degraded porcine aorta samples were used as a model of ECM degradation in abdominal aortic aneurysm (AAA). After enzymatic treatment, Fourier transform infrared (FTIR) spectra of the aortic tissue were acquired by an infrared fiber optic probe (IFOP) and FTIR imaging spectroscopy (FT-IRIS). Collagen and elastin content were quantified biochemically and partial least squares (PLS) models were developed to predict collagen and elastin content in aorta based on FTIR spectra. PLS models developed from FT-IRIS spectra were able to predict elastin and collagen content of the samples with strong correlations (RMSE of validation = 8.4% and 11.1% of the range respectively), and IFOP spectra were successfully used to predict elastin content (RMSE = 11.3% of the range). The PLS regression coefficients from the FT-IRIS models were used to map collagen and elastin in tissue sections of degraded porcine aortic tissue as well as a human AAA biopsy tissue, creating a similar map of each component compared to histology. These results support further application of FTIR spectroscopic techniques for evaluation of AAA tissues. PMID:24761431

  1. Novel high-temperature and pressure-compatible ultrasonic levitator apparatus coupled to Raman and Fourier transform infrared spectrometers.

    PubMed

    Brotton, Stephen J; Kaiser, Ralf I

    2013-05-01

    We describe an original apparatus comprising of an acoustic levitator enclosed within a pressure-compatible process chamber. To characterize any chemical and physical modifications of the levitated particle, the chamber is interfaced to complimentary, high-sensitivity Raman (4390-170 cm(-1)), and Fourier transform infrared (FTIR) (10,000-500 cm(-1)) spectroscopic probes. The temperature of the levitated particle can be accurately controlled by heating using a carbon dioxide laser emitting at 10.6 μm. The advantages of levitating a small particle combined with the two spectroscopic probes, process chamber, and infrared laser heating makes novel experiments possible relevant to the fields of, for example, planetary science, astrobiology, and combustion chemistry. We demonstrate that this apparatus is well suited to study the dehydration of a variety of particles including minerals and biological samples; and offers the possibility of investigating combustion processes involving micrometer-sized particles such as graphite. Furthermore, we show that the FTIR spectrometer enables the study of chemical reactions on the surfaces of porous samples and scientifically and technologically relevant, micrometer-thick levitated sheets. The FTIR spectrometer can also be used to investigate non-resonant and resonant scattering from small, irregularly-shaped particles across the mid-infrared range from 2.5 μm to 25 μm, which is relevant to scattering from interplanetary dust and biological, micrometer-sized samples but cannot be accurately modelled using Mie theory.

  2. Novel high-temperature and pressure-compatible ultrasonic levitator apparatus coupled to Raman and Fourier transform infrared spectrometers

    NASA Astrophysics Data System (ADS)

    Brotton, Stephen J.; Kaiser, Ralf I.

    2013-05-01

    We describe an original apparatus comprising of an acoustic levitator enclosed within a pressure-compatible process chamber. To characterize any chemical and physical modifications of the levitated particle, the chamber is interfaced to complimentary, high-sensitivity Raman (4390-170 cm-1), and Fourier transform infrared (FTIR) (10 000-500 cm-1) spectroscopic probes. The temperature of the levitated particle can be accurately controlled by heating using a carbon dioxide laser emitting at 10.6 μm. The advantages of levitating a small particle combined with the two spectroscopic probes, process chamber, and infrared laser heating makes novel experiments possible relevant to the fields of, for example, planetary science, astrobiology, and combustion chemistry. We demonstrate that this apparatus is well suited to study the dehydration of a variety of particles including minerals and biological samples; and offers the possibility of investigating combustion processes involving micrometer-sized particles such as graphite. Furthermore, we show that the FTIR spectrometer enables the study of chemical reactions on the surfaces of porous samples and scientifically and technologically relevant, micrometer-thick levitated sheets. The FTIR spectrometer can also be used to investigate non-resonant and resonant scattering from small, irregularly-shaped particles across the mid-infrared range from 2.5 μm to 25 μm, which is relevant to scattering from interplanetary dust and biological, micrometer-sized samples but cannot be accurately modelled using Mie theory.

  3. Study on Angelica and its different extracts by Fourier transform infrared spectroscopy and two-dimensional correlation IR spectroscopy

    NASA Astrophysics Data System (ADS)

    Liu, Hong-xia; Sun, Su-qin; Lv, Guang-hua; Chan, Kelvin K. C.

    2006-05-01

    In order to develop a rapid and effective analysis method for studying integrally the main constituents in the medicinal materials and their extracts, discriminating the extracts from different extraction process, comparing the categories of chemical constituents in the different extracts and monitoring the qualities of medicinal materials, we applied Fourier transform infrared spectroscopy (FT-IR) associated with second derivative infrared spectroscopy and two-dimensional correlation infrared spectroscopy (2D-IR) to study the main constituents in traditional Chinese medicine Angelica and its different extracts (extracted by petroleum ether, ethanol and water in turn). The findings indicated that FT-IR spectrum can provide many holistic variation rules of chemical constituents. Use of the macroscopical fingerprint characters of FT-IR and 2D-IR spectrum can not only identify the main chemical constituents in medicinal materials and their different extracts, but also compare the components differences among the similar samples. This analytical method is highly rapid, effective, visual and accurate for pharmaceutical research.

  4. Characterization of the surfaces of platinum/tin oxide based catalysts by Fourier Transform Infrared Spectroscopy (FTIR)

    NASA Technical Reports Server (NTRS)

    Keiser, Joseph T.; Upchurch, Billy T.

    1990-01-01

    A Pt/SnO2 catalyst has been developed at NASA Langley that is effective for the oxidation of CO at room temperature (1). A mechanism has been proposed to explain the effectiveness of this catalyst (2), but most of the species involved in this mechanism have not been observed under actual catalytic conditions. A number of these species are potentially detectable by Fourier Transform Infrared Spectroscopy (FTIR), e.g., HOSnO sub x, HO sub y PtO sub z, Pt-CO, and SnHCO3. Therefore a preliminary investigation was conducted to determine what might be learned about this particular catalyst by transmission FTIR. The main advantage of FTIR for this work is that the catalyst can be examined under conditions similar to the actual catalytic conditions. This can be of critical importance since some surface species may exist only when the reaction gases are present. Another advantage of the infrared approach is that since vibrations are probed, subtle chemical details may be obtained. The main disadvantage of this approach is that FTIR is not nearly as sensitive as the Ultra High Vacuum (UHV) surface analytical techniques such as Auger, Electron Spectroscopy for Chemical Analysis (ESCA), Electron Energy Loss Spectroscopy (EELS), etc. Another problem is that the assignment of the observed infrared bands may be difficult.

  5. In situ infrared spectroscopy study of the interface self-cleaning during the atomic layer deposition of HfO2 on GaAs(100) surfaces

    NASA Astrophysics Data System (ADS)

    Ye, Liwang; Gougousi, Theodosia

    2014-09-01

    In situ attenuated total reflectance Fourier transform infrared spectroscopy was utilized to study the interface evolution during the atomic layer deposition (ALD) of HfO2 on GaAs surfaces using of tetrakis (dimethylamino) hafnium and H2O. The experiments were performed on chemical oxide and hydrogen fluoride etched GaAs(100) starting surfaces. For the deposition of HfO2 on chemical oxide GaAs surfaces at 275 °C, which corresponds to the optimal ALD process temperature, continuous arsenic oxide removal was observed for the first 20 ALD cycles. The oxide removal was more pronounced at the initial 1-2 cycles but nonetheless persisted, at a reduced rate, up to the 20th cycle. The substrate temperature was confirmed to affect the arsenic oxide removal; the rate was significant at temperatures above 250 °C while negligible below 200 °C.

  6. [Using 2-DCOS to identify the molecular spectrum peaks for the isomer in the multi-component mixture gases Fourier transform infrared analysis].

    PubMed

    Zhao, An-Xin; Tang, Xiao-Jun; Zhang, Zhong-Hua; Liu, Jun-Hua

    2014-10-01

    The generalized two-dimensional correlation spectroscopy and Fourier transform infrared were used to identify hydrocarbon isomers in the mixed gases for absorption spectra resolution enhancement. The Fourier transform infrared spectrum of n-butane and iso-butane and the two-dimensional correlation infrared spectrum of concentration perturbation were used for analysis as an example. The all band and the main absorption peak wavelengths of Fourier transform infrared spectrum for single component gas showed that the spectra are similar, and if they were mixed together, absorption peaks overlap and peak is difficult to identify. The synchronous and asynchronous spectrum of two-dimensional correlation spectrum can clearly identify the iso-butane and normal butane and their respective characteristic absorption peak intensity. Iso-butane has strong absorption characteristics spectrum lines at 2,893, 2,954 and 2,893 cm(-1), and n-butane at 2,895 and 2,965 cm(-1). The analysis result in this paper preliminary verified that the two-dimensional infrared correlation spectroscopy can be used for resolution enhancement in Fourier transform infrared spectrum quantitative analysis. PMID:25739197

  7. [Optical properties research of NH4NO3 by Fourier transform infrared spectroscopy].

    PubMed

    Liu, Na; Wei, Xiu-Li; Gao, Min-Guang; Xu, Liang; Tong, Jing-Jing; Li, Xiang-Xian; Jin, Ling

    2013-07-01

    In the present paper, the infrared spectrum of aerosol and NH4 NO3 was analysed and compared, and the result showed that the infrared spectral features of aerosol are consistent with that of NH4 NO3. The absorption coefficient alpha and the mass absorption cross section kappa of NO3- was calculated by the transmissivity of NO3- in NH4 NO3 according to Beer-Lambert law. Then the imaginary part of the complex refractive index was calculated through alpha. The real part of the complex refractive index was derived from the K-K(Kramers-Kroning) relationship. It has important significance for further research on the scattering and absorption characteristics of the different composition of the atmospheric aerosol through analysing the results of the experiment. PMID:24059172

  8. Diffuse reflectance infrared Fourier-Transform spectra of selected organic compounds

    SciTech Connect

    Harmon, S.H.; Caton, J.E.

    1982-05-01

    Diffuse reflectance infrared spectra of a variety of different organic compounds have been determined. Profiles of the spectra along with the location and relative intensity of the principal bands have been included for each compound studied. In addition both diffuse reflectance and transmittance infrared spectra were obtained for the same samples, and the spectral results were compared. Although some minor variations are observed between a diffuse reflectance spectrum and the corresponding transmittance spectrum, the diffuse reflectance is quite useful and may be a superior technique for the study of many samples because it possesses an inherently higher signal-to-noise response, requires less sample preparation and allows a very wide range of samples (solids, liquids of low volatility, neat sample, or sample diluted in a reflecting medium) to be studied under very similar conditions.

  9. [Optical properties research of NH4NO3 by Fourier transform infrared spectroscopy].

    PubMed

    Liu, Na; Wei, Xiu-Li; Gao, Min-Guang; Xu, Liang; Tong, Jing-Jing; Li, Xiang-Xian; Jin, Ling

    2013-07-01

    In the present paper, the infrared spectrum of aerosol and NH4 NO3 was analysed and compared, and the result showed that the infrared spectral features of aerosol are consistent with that of NH4 NO3. The absorption coefficient alpha and the mass absorption cross section kappa of NO3- was calculated by the transmissivity of NO3- in NH4 NO3 according to Beer-Lambert law. Then the imaginary part of the complex refractive index was calculated through alpha. The real part of the complex refractive index was derived from the K-K(Kramers-Kroning) relationship. It has important significance for further research on the scattering and absorption characteristics of the different composition of the atmospheric aerosol through analysing the results of the experiment.

  10. Synchrotron Based Fourier Transform Far-Infrared Spectroscopy of CH3NO2

    NASA Astrophysics Data System (ADS)

    Twagirayezu, Sylvestre; Billinghurst, Brant E.; May, Tim; Dawadi, Mahesh B.; Perry, David S.

    2013-06-01

    As a slightly asymmetric top molecule (κ = 0.25) with both a free internal rotor and a methyl group, CH_3NO_2 is a benchmark system for studies of torsional motion in a 6-fold potential and of the coupling between a large amplitude vibration and other small-amplitude vibrations. For this purpose, rotationally resolved infrared spectra of CH_3NO_2, have been recorded using the Far-Infrared beamline at the Canadian Light Source, which is equipped with a high resolution Bruker IFS 125HR spectrometer. The observed infrared spectra, in the range 550-1000cm^{-1}, are the average of 300 interferometer scans collected at a nominal resolution of 0.00096cm^{-1}. Two a-type bands, centered at 657.08cm^{-1}for NO symmetric bend and at 917.99cm^{-1}for CN-stretch, have been measured. The initial analysis of a number of torsional states is currently being carried out and the progress will be reported in this talk.

  11. Physical reasons of emission transformation in infrared CdSeTe/ZnS quantum dots at bioconjugation

    NASA Astrophysics Data System (ADS)

    Torchynska, T. V.

    2015-04-01

    The core/shell CdSeTe/ZnS quantum dots (QDs) with emission at 780-800 nm (1.55-1.60 eV) have been studied by means of photoluminescence (PL) and Raman scattering methods in the nonconjugated state and after conjugation to different antibodies (Ab): (i) mouse monoclonal [8C9] human papilloma virus Ab, anti-HPV 16-E7 Ab, (ii) mouse monoclonal [C1P5] human papilloma virus HPV16 E6+HPV18 E6 Ab, and (iii) pseudo rabies virus (PRV) Ab. The transformations of PL and Raman scattering spectra of QDs, stimulated by conjugated antibodies, have been revealed and discussed. The energy band diagram of core/shell CdSeTe/ZnS QDs has been designed that helps to analyze the PL spectra and their transformations at the bioconjugation. It is shown that the core in CdSeTe/ZnS QDs is complex and including the type II quantum well. The last fact permits to explain the nature of infrared (IR) optical transitions (1.55-1.60 eV) and the high energy PL band (1.88-1.94 eV) in the nonconjugated and bioconjugated QDs. A set of physical reasons has been analyzed with the aim to explain the transformation of PL spectra in bioconjugated QDs. Finally it is shown that two factors are responsible for the PL spectrum transformation at bioconjugation to charged antibodies: (i) the change of energy band profile in QDs and (ii) the shift of QD energy levels in the strong quantum confinement case. The effect of PL spectrum transformation is useful for the study of QD bioconjugation to specific antibodies and can be a powerful technique for early medical diagnostics.

  12. Probing atomic scale transformation of fossil dental enamel using Fourier transform infrared and nuclear magnetic resonance spectroscopy: a case study from the Tugen Hills (Rift Gregory, Kenya).

    PubMed

    Yi, Haohao; Balan, Etienne; Gervais, Christel; Ségalen, Loïc; Roche, Damien; Person, Alain; Fayon, Franck; Morin, Guillaume; Babonneau, Florence

    2014-09-01

    A series of fossil tooth enamel samples was investigated by Fourier transform infrared (FTIR) spectroscopy, (13)C and (19)F magic-angle spinning nuclear magnetic resonance (MAS NMR) and scanning electron microscopy (SEM). Tooth remains were collected in Mio-Pliocene deposits of the Tugen Hills in Kenya. Significant transformations were observed in fossil enamel as a function of increasing fluorine content (up to 2.8wt.%). FTIR spectroscopy revealed a shift of the ν1 PO4 stretching band to higher frequency. The ν2 CO3 vibrational band showed a decrease in the intensity of the primary B-type carbonate signal, which was replaced by a specific band at 864cm(-1). This last band was ascribed to a specific carbonate environment in which the carbonate group is closely associated to a fluoride ion. The occurrence of this carbonate defect was consistently attested by the observation of two different fluoride signals in the (19)F NMR spectra. One main signal, at ∼-100ppm, is related to structural F ions in the apatite channel and the other, at -88ppm, corresponds to the composite defect. These spectroscopic observations can be understood as resulting from the mixture of two phases: biogenic hydroxylapatite (bioapatite) and secondary fluorapatite. SEM observations of the most altered sample confirmed the extensive replacement of the bioapatite by fluorapatite, resulting from the dissolution of the primary bioapatite followed by the precipitation of carbonate-fluorapatite. The ν2 CO3 IR bands can be efficiently used to monitor the extent of this type of bioapatite transformation during fossilization.

  13. [Discrimination of polysaccharides from Angelica sinensis and its different processed products based on Fourier transform infrared spectroscopy].

    PubMed

    Ji, Peng; Wei, Yan-Ming; Hua, Yong-Li; Zhang, Wen-quan

    2014-05-01

    A new rapid and nondestructive method for identifying polysaccharides from Angelica sinensis and its different processed products was developed, and this method was based on Fourier transform infrared spectroscopy (FTIR). In the clinic of traditional Chinese medicine, unprocessed Angelica sinensis(UAS) is of ten used after processed, the common processed products are Angelica sinensis parched with wine(WAS), Angelica sinensis parched with soil(SAS), Angelica sinensis parched with oil(OAS) and Charred Angelica sinensis(CAS). In order to use polysaccharides from Angelica sinensis and its processed products effectively and reasonably in clinic, it is very necessary to identify them. FTIR of polysaccharides from Angelica sinensis and its different processed products was determined, and then it was decomposed by discrete wavelet transform (DWT). The high frequency information in scale 2, 3 and 4 was selected as feature information, from which the each wavelet entropy was extracted as characteristic value. BP neural network was trained with these characteristic values. The trained BP neural network was used to identify polysaccharides from Angelica sinensis and its different processed products. According to 30 prediction samples, the correct rate for recognition was 93. 3%, which indicates that: it has better feasibility to identify polysaccharides from Angelica sinensis and its different processed products by this method, which is based on FTIR, discrete wavelet transform and BP neural network PMID:25095420

  14. Blood Clearance, Distribution, Transformation, Excretion, and Toxicity of Near-Infrared Quantum Dots Ag2Se in Mice.

    PubMed

    Tang, Huan; Yang, Sheng-Tao; Yang, Yi-Fan; Ke, Da-Ming; Liu, Jia-Hui; Chen, Xing; Wang, Haifang; Liu, Yuanfang

    2016-07-20

    As a novel fluorescent probe in the second near-infrared window, Ag2Se quantum dots (QDs) exhibit great prospect in in vivo imaging due to their maximal penetration depth and negligible background. However, the in vivo behavior and toxicity of Ag2Se QDs still largely remain unknown, which severely hinders their wide-ranging biomedical applications. Herein, we systematically studied the blood clearance, distribution, transformation, excretion, and toxicity of polyethylene glycol (PEG) coated Ag2Se QDs in mice after intravenous administration with a high dose of 8 μmol/kg body weight. QDs are quickly cleared from the blood with a circulation half-life of 0.4 h. QDs mainly accumulate in liver and spleen and are remarkably transformed into Ag and Se within 1 week. Ag is excreted from the body readily through both feces and urine, whereas Se is excreted hardly. The toxicological evaluations demonstrate that there is no overt acute toxicity of Ag2Se QDs to mice. Moreover, in regard to the in vivo stability problem of Ag2Se QDs, the biotransformation and its related metabolism are intensively discussed, and some promising coating means for Ag2Se QDs to avert transformation are proposed as well. Our work lays a solid foundation for safe applications of Ag2Se QDs in bioimaging in the future. PMID:27351208

  15. [Discrimination of polysaccharides from Angelica sinensis and its different processed products based on Fourier transform infrared spectroscopy].

    PubMed

    Ji, Peng; Wei, Yan-Ming; Hua, Yong-Li; Zhang, Wen-quan

    2014-05-01

    A new rapid and nondestructive method for identifying polysaccharides from Angelica sinensis and its different processed products was developed, and this method was based on Fourier transform infrared spectroscopy (FTIR). In the clinic of traditional Chinese medicine, unprocessed Angelica sinensis(UAS) is of ten used after processed, the common processed products are Angelica sinensis parched with wine(WAS), Angelica sinensis parched with soil(SAS), Angelica sinensis parched with oil(OAS) and Charred Angelica sinensis(CAS). In order to use polysaccharides from Angelica sinensis and its processed products effectively and reasonably in clinic, it is very necessary to identify them. FTIR of polysaccharides from Angelica sinensis and its different processed products was determined, and then it was decomposed by discrete wavelet transform (DWT). The high frequency information in scale 2, 3 and 4 was selected as feature information, from which the each wavelet entropy was extracted as characteristic value. BP neural network was trained with these characteristic values. The trained BP neural network was used to identify polysaccharides from Angelica sinensis and its different processed products. According to 30 prediction samples, the correct rate for recognition was 93. 3%, which indicates that: it has better feasibility to identify polysaccharides from Angelica sinensis and its different processed products by this method, which is based on FTIR, discrete wavelet transform and BP neural network

  16. The Kinetics of Mo(Co)6 Substitution Monitored by Fourier Transform Infrared Spectrophotometry.

    ERIC Educational Resources Information Center

    Suslick, Kenneth S.; And Others

    1987-01-01

    Describes a physical chemistry experiment that uses Fourier transform (FTIR) spectrometers and microcomputers as a way of introducing students to the spectral storage and manipulation techniques associated with digitized data. It can be used to illustrate FTIR spectroscopy, simple kinetics, inorganic mechanisms, and Beer's Law. (TW)

  17. Infrared Spectroscopy as a Tool to Study the Antioxidant Activity of Polyphenolic Compounds in Isolated Rat Enterocytes

    PubMed Central

    Barraza-Garza, Guillermo; Castillo-Michel, Hiram; de la Rosa, Laura A.; Martinez-Martinez, Alejandro; Pérez-León, Jorge A.; Cotte, Marine; Alvarez-Parrilla, Emilio

    2016-01-01

    The protective effect of different polyphenols, catechin (Cat), quercetin (Qc) (flavonoids), gallic acid (GA), caffeic acid (CfA), chlorogenic acid (ChA) (phenolic acids), and capsaicin (Cap), against H2O2-induced oxidative stress was evaluated in rat enterocytes using Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR) Spectroscopy and Fourier Transform Infrared Microspectroscopy (FTIRM), and results were compared to standard lipid peroxidation techniques: conjugated dienes (CD) and Thiobarbituric Acid Reactive Substances (TBARS). Analysis of ATR-FTIR and FTIRM spectral data allowed the simultaneous evaluation of the effects of H2O2 and polyphenols on lipid and protein oxidation. All polyphenols showed a protective effect against H2O2-induced oxidative stress in enterocytes, when administered before or after H2O2. Cat and capsaicin showed the highest protective effect, while phenolic acids had weaker effects and Qc presented a mild prooxidative effect (IR spectral profile of biomolecules between control and H2O2-treated cells) according to FTIR analyses. These results demonstrated the viability to use infrared spectroscopy to evaluate the oxidant and antioxidant effect of molecules in cell systems assays. PMID:27213031

  18. Infrared Spectroscopy as a Tool to Study the Antioxidant Activity of Polyphenolic Compounds in Isolated Rat Enterocytes.

    PubMed

    Barraza-Garza, Guillermo; Castillo-Michel, Hiram; de la Rosa, Laura A; Martinez-Martinez, Alejandro; Pérez-León, Jorge A; Cotte, Marine; Alvarez-Parrilla, Emilio

    2016-01-01

    The protective effect of different polyphenols, catechin (Cat), quercetin (Qc) (flavonoids), gallic acid (GA), caffeic acid (CfA), chlorogenic acid (ChA) (phenolic acids), and capsaicin (Cap), against H2O2-induced oxidative stress was evaluated in rat enterocytes using Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR) Spectroscopy and Fourier Transform Infrared Microspectroscopy (FTIRM), and results were compared to standard lipid peroxidation techniques: conjugated dienes (CD) and Thiobarbituric Acid Reactive Substances (TBARS). Analysis of ATR-FTIR and FTIRM spectral data allowed the simultaneous evaluation of the effects of H2O2 and polyphenols on lipid and protein oxidation. All polyphenols showed a protective effect against H2O2-induced oxidative stress in enterocytes, when administered before or after H2O2. Cat and capsaicin showed the highest protective effect, while phenolic acids had weaker effects and Qc presented a mild prooxidative effect (IR spectral profile of biomolecules between control and H2O2-treated cells) according to FTIR analyses. These results demonstrated the viability to use infrared spectroscopy to evaluate the oxidant and antioxidant effect of molecules in cell systems assays. PMID:27213031

  19. Fourier-transform infrared study of the behavior of grease in lubricated contacts

    SciTech Connect

    Cann, P.M.; Spikes, H.A. )

    1992-04-01

    Changes in the structure (and thus the properties) of two grease lubricants (two different concentrations of lithium hydroxystearate soap thickener in a mineral oil), brought about by rubbing of greased contacts were investigated using infrared microspectroscopy. Comparisons are made of spectra obtained on rubbed surfaces out of contact and those directly within contacts during rubbing. Data on changes in the composition, the molecular alignment, and bonding of the various components of the lubricants, which resulted from shear were obtained using three experimental methods: the cone-on-plate method, the sliding EHD contact method of Cann and Spikes (1991) using FTIR spectroscopy, and a hydrodynamic contact method. 17 refs.

  20. Fourier transform infrared spectroscopy study on order-disorder transition in Langmuir-Blodgett films of 7-(2-octadecyloxycarbonylethyl)guanine before and after recognition to cytidine.

    PubMed

    Miao, Wangen; Luo, Xuzhong; Wu, Sanxie; Liang, Yingqiu

    2004-01-01

    Order-disorder transitions of 9-monolayer Langmuir-Blodgett (LB) films of 7-(2-octadecyloxycarbonylethyl)guanine (ODCG) before and after recognition to cytidine were investigated by Fourier transform infrared (FTIR) spectroscopy. The different order-disorder transitions suggest that molecular recognition between ODCG and cytidine influence these two LB films on the order-disorder process of alkyl tailchain. Cleavage of the multi-hydrogen bonds was also observed by the infrared spectroscopy at elevated temperature.

  1. A novel image enhancement algorithm based on stationary wavelet transform for infrared thermography to the de-bonding defect in solid rocket motors

    NASA Astrophysics Data System (ADS)

    Liu, Tao; Zhang, Wei; Yan, Shaoze

    2015-10-01

    In this paper, a multi-scale image enhancement algorithm based on low-passing filtering and nonlinear transformation is proposed for infrared testing image of the de-bonding defect in solid propellant rocket motors. Infrared testing images with high-level noise and low contrast are foundations for identifying defects and calculating the defects size. In order to improve quality of the infrared image, according to distribution properties of the detection image, within framework of stationary wavelet transform, the approximation coefficients at suitable decomposition level is processed by index low-passing filtering by using Fourier transform, after that, the nonlinear transformation is applied to further process the figure to improve the picture contrast. To verify validity of the algorithm, the image enhancement algorithm is applied to infrared testing pictures of two specimens with de-bonding defect. Therein, one specimen is made of a type of high-strength steel, and the other is a type of carbon fiber composite. As the result shown, in the images processed by the image enhancement algorithm presented in the paper, most of noises are eliminated, and contrast between defect areas and normal area is improved greatly; in addition, by using the binary picture of the processed figure, the continuous defect edges can be extracted, all of which show the validity of the algorithm. The paper provides a well-performing image enhancement algorithm for the infrared thermography.

  2. Fourier transform infrared spectral detection of life in polar subsurface environments and its application to Mars exploration.

    PubMed

    Preston, Louisa J; Johnson, Diane; Cockell, Charles S; Grady, Monica M

    2015-09-01

    Cryptoendolithic lichen communities of the Dry Valleys, Antarctica, survive in an extremely inhospitable environment, finding refuge in microscopic niches where conditions suitable for life exist. Such "within-rock" communities may have evolved on Mars when conditions for life on the surface deteriorated to such an extent that they could no longer survive. Fourier transform infrared spectroscopy of unprepared whole-rock Antarctic Beacon sandstones was used to vertically profile molecular vibrations of fatty acids, proteins, and carboxylic acids created by endolithic communities. Spectral biosignatures were found localized to lichen-rich areas and were absent in crustal regions and the bulk rock substrate. These cryptoendolithic profiles will aid similar spectroscopic investigations of organic biosignatures during future Martian subsurface studies and will help in the identification of similar communities in other localities across the Earth.

  3. Simple, fast, and accurate methodology for quantitative analysis using Fourier transform infrared spectroscopy, with bio-hybrid fuel cell examples.

    PubMed

    Mackie, David M; Jahnke, Justin P; Benyamin, Marcus S; Sumner, James J

    2016-01-01

    The standard methodologies for quantitative analysis (QA) of mixtures using Fourier transform infrared (FTIR) instruments have evolved until they are now more complicated than necessary for many users' purposes. We present a simpler methodology, suitable for widespread adoption of FTIR QA as a standard laboratory technique across disciplines by occasional users.•Algorithm is straightforward and intuitive, yet it is also fast, accurate, and robust.•Relies on component spectra, minimization of errors, and local adaptive mesh refinement.•Tested successfully on real mixtures of up to nine components. We show that our methodology is robust to challenging experimental conditions such as similar substances, component percentages differing by three orders of magnitude, and imperfect (noisy) spectra. As examples, we analyze biological, chemical, and physical aspects of bio-hybrid fuel cells.

  4. Discrimination of healthy and osteoarthritic articular cartilages by Fourier transform infrared imaging and partial least squares-discriminant analysis

    NASA Astrophysics Data System (ADS)

    Zhang, Xue-Xi; Yin, Jian-Hua; Mao, Zhi-Hua; Xia, Yang

    2015-06-01

    Fourier transform infrared imaging (FTIRI) combined with chemometrics algorithm has strong potential to obtain complex chemical information from biology tissues. FTIRI and partial least squares-discriminant analysis (PLS-DA) were used to differentiate healthy and osteoarthritic (OA) cartilages for the first time. A PLS model was built on the calibration matrix of spectra that was randomly selected from the FTIRI spectral datasets of healthy and lesioned cartilage. Leave-one-out cross-validation was performed in the PLS model, and the fitting coefficient between actual and predicted categorical values of the calibration matrix reached 0.95. In the calibration and prediction matrices, the successful identifying percentages of healthy and lesioned cartilage spectra were 100% and 90.24%, respectively. These results demonstrated that FTIRI combined with PLS-DA could provide a promising approach for the categorical identification of healthy and OA cartilage specimens.

  5. Identification of a Methane Oxidation Intermediate on Solid Oxide Fuel Cell Anode Surfaces with Fourier Transform Infrared Emission.

    PubMed

    Pomfret, Michael B; Steinhurst, Daniel A; Owrutsky, Jeffrey C

    2013-04-18

    Fuel interactions on solid oxide fuel cell (SOFC) anodes are studied with in situ Fourier transform infrared emission spectroscopy (FTIRES). SOFCs are operated at 800 °C with CH4 as a representative hydrocarbon fuel. IR signatures of gas-phase oxidation products, CO2(g) and CO(g), are observed while cells are under load. A broad feature at 2295 cm(-1) is assigned to CO2 adsorbed on Ni as a CH4 oxidation intermediate during cell operation and while carbon deposits are electrochemically oxidized after CH4 operation. Electrochemical control provides confirmation of the assignment of adsorbed CO2. FTIRES has been demonstrated as a viable technique for the identification of fuel oxidation intermediates and products in working SOFCs, allowing for the elucidation of the mechanisms of fuel chemistry.

  6. The use of Fourier-transform infrared spectroscopy for the quantitative determination of glucose concentration in whole blood.

    PubMed

    Shen, Y C; Davies, A G; Linfleld, E H; Elsey, T S; Taday, P F; Arnone, D D

    2003-07-01

    Fourier-transform infrared transmission spectroscopy has been used for the determination of glucose concentration in whole blood samples from 28 patients. A 4-vector partial least-squares calibration model, using the spectral range 950-1200 cm(-1), yielded a standard-error-of-prediction of 0.59 mM for an independent test set. For blood samples from a single patient, we found that the glucose concentration was proportional to the difference between the values of the second derivative spectrum at 1082 cm(-1) and 1093 cm(-1). This indicates that spectroscopy at these two specific wavenumbers alone could be used to determine the glucose concentration in blood plasma samples from a single patient, with a prediction error of 0.95 mM. PMID:12884933

  7. Remote detection of biological aerosols at a distance of 3 km with a passive Fourier transform infrared (FTIR) sensor.

    PubMed

    Ben-David, Avishai

    2003-03-10

    Bio-aerosols containing Bacillus subtilis var. niger (BG) were detected at a distance of 3 km with a passive Fourier Transform InfraRed (FTIR) spectrometer in an open-air environment where the thermal contrast was low (~ 1 K). The measurements were analyzed with a new hyperspectral detection, identification and estimation algorithm based on radiative transfer theory and advanced signal processing techniques that statistically subtract the undesired background spectra. The results are encouraging as they suggest for the first time the feasibility of detecting biological aerosols with passive FTIR sensors. The number of detection events was small but statistically significant. We estimate the false alarm rate for this experiment to be 0.0095 and the probability of detection to be 0.61 when a threshold of detection that minimizes the sum of the probabilities of false alarm and of missed detection is chosen. PMID:19461748

  8. Remote detection of biological aerosols at a distance of 3 km with a passive Fourier transform infrared (FTIR) sensor

    NASA Astrophysics Data System (ADS)

    Ben-David, Avishai

    2003-03-01

    Bio-aerosols containing Bacillus subtilis var. niger (BG) were detected at a distance of 3 km with a passive Fourier Transform InfraRed (FTIR) spectrometer in an open-air environment where the thermal contrast was low (~ 1 K). The measurements were analyzed with a new hyperspectral detection, identification and estimation algorithm based on radiative transfer theory and advanced signal processing techniques that statistically subtract the undesired background spectra. The results are encouraging as they suggest for the first time the feasibility of detecting biological aerosols with passive FTIR sensors. The number of detection events was small but statistically significant. We estimate the false alarm rate for this experiment to be 0.0095 and the probability of detection to be 0.61 when a threshold of detection that minimizes the sum of the probabilities of false alarm and of missed detection is chosen.

  9. Simple, fast, and accurate methodology for quantitative analysis using Fourier transform infrared spectroscopy, with bio-hybrid fuel cell examples

    PubMed Central

    Mackie, David M.; Jahnke, Justin P.; Benyamin, Marcus S.; Sumner, James J.

    2016-01-01

    The standard methodologies for quantitative analysis (QA) of mixtures using Fourier transform infrared (FTIR) instruments have evolved until they are now more complicated than necessary for many users’ purposes. We present a simpler methodology, suitable for widespread adoption of FTIR QA as a standard laboratory technique across disciplines by occasional users.•Algorithm is straightforward and intuitive, yet it is also fast, accurate, and robust.•Relies on component spectra, minimization of errors, and local adaptive mesh refinement.•Tested successfully on real mixtures of up to nine components. We show that our methodology is robust to challenging experimental conditions such as similar substances, component percentages differing by three orders of magnitude, and imperfect (noisy) spectra. As examples, we analyze biological, chemical, and physical aspects of bio-hybrid fuel cells. PMID:26977411

  10. Fourier transform infrared studies of model polar stratospheric cloud surfaces - Growth and evaporation of ice and nitric acid/ice

    NASA Technical Reports Server (NTRS)

    Tolbert, Margaret A.; Middlebrook, Ann M.

    1990-01-01

    Fourier-transform infrared surface studies are used to probe the microphysical properties of nitric acid trihydrate (NAT) and ice films representative of type I and II polar stratospheric clouds (PSC). Experiments indicate that, on initial exposure to 1.8 microtorr of HNO3, a layer of ice is quantitatively converted to NAT. However, conversion of ice to NAT does not proceed indefinitely, but rather the system reaches saturation. For longer exposures or higher HNO3 pressures, NAM becomes the dominant nitric acid containing species on the surface. Evaporation studies were performed to test the feasibility of a recent denitrification mechanism. The results indicate that ice coated with 0.20 micron of NAT evaporates at a temperature of about 4 C higher than uncoated ice.

  11. Quantitative zonal differentiation of articular cartilage by microscopic magnetic resonance imaging, polarized light microscopy, and Fourier-transform infrared imaging.

    PubMed

    Lee, Ji Hyun; Xia, Yang

    2013-06-01

    This study aimed to synchronize the zonal differentiation of the full-thickness articular cartilage by three micro-imaging techniques, namely microscopic magnetic resonance imaging (µMRI), polarized light microscopy (PLM), and Fourier-transform infrared imaging (FTIRI). Eighteen cartilage-bone blocks from three canine humeral joints were imaged by: (a) µMRI T2 relaxation at 0° and 55° orientations in a 7 T magnetic field, (b) PLM optical retardation and azimuthal angle, and (c) FTIRI amide I and amide II anisotropies at 0° and 90° polarizations relative to the articular surface. In addition, µMRI T1 relaxation was imaged before and after the tissue being immersed in gadolinium (contrast agent) solution, to calculate the proteoglycan concentration. A set of previously established criteria in cartilage imaging was revised. The new criteria could simultaneously correlate the thicknesses of the three consecutive subtissue zones in articular cartilage among these imaging techniques.

  12. Fourier transform infrared spectral detection of life in polar subsurface environments and its application to Mars exploration.

    PubMed

    Preston, Louisa J; Johnson, Diane; Cockell, Charles S; Grady, Monica M

    2015-09-01

    Cryptoendolithic lichen communities of the Dry Valleys, Antarctica, survive in an extremely inhospitable environment, finding refuge in microscopic niches where conditions suitable for life exist. Such "within-rock" communities may have evolved on Mars when conditions for life on the surface deteriorated to such an extent that they could no longer survive. Fourier transform infrared spectroscopy of unprepared whole-rock Antarctic Beacon sandstones was used to vertically profile molecular vibrations of fatty acids, proteins, and carboxylic acids created by endolithic communities. Spectral biosignatures were found localized to lichen-rich areas and were absent in crustal regions and the bulk rock substrate. These cryptoendolithic profiles will aid similar spectroscopic investigations of organic biosignatures during future Martian subsurface studies and will help in the identification of similar communities in other localities across the Earth. PMID:26414525

  13. Photochemistry of a Puckered Ferracyclobutadiene in Liquid Solution Studied by Time-Resolved Fourier-Transform Infrared Spectroscopy.

    PubMed

    Torres-Alacan, Joel; Das, Ujjal; Wezisla, Boris; Straßmann, Martin; Filippou, Alexander C; Vöhringer, Peter

    2015-11-23

    Flash photolysis combined with step-scan and rapid-scan Fourier-transform infrared spectroscopy was carried out to explore the photochemistry of a puckered, quasi-square pyramidal ferracyclobutadiene, [Fe{κ(2) -C3 (NEt2 )3 }(CO)3 ]BF4 ([1]BF4 ), that features three additional carbonyl ligands in the metal coordination sphere. In liquid solution at room temperature, an excitation with λ=355 nm light resulted in the loss of one CO ligand, which is cleaved from a basal metal-coordination site. Within the time resolution of the experiment, a solvent molecule promptly refills the resultant vacancy at the coordinatively unsaturated metal center. In the weakly interacting liquid, dichloromethane, the counterion of the complex is subsequently able to substitute the solvent in the coordination sphere of the iron center, thereby forming as a stable product a neutral dicarbonyl tetrafluoroborato iron(0) species containing a four-membered ferracycle. PMID:26457465

  14. On the application of Open-Path Fourier Transform Infra-Red spectroscopy to measure aerosols: Observations of water droplets

    SciTech Connect

    Hashmonay, R.A.; Yost, M.G.

    1999-04-01

    This paper proposes the application of Open-Path Fourier Transform Infra-Red (OP-FTIR) spectroscopy to measure aerosols. A preliminary experiment conducted in a standard shower chamber generated a condensed water aerosol cloud. The OP-FTIR beam acquired spectra through the cloud of water droplets. The authors matched calculated extinction spectra to measured extinction in the spectral range between 500 and 5,000 wavenumbers by using Mie theory for spherical particles. The results indicate that size distribution parameters may be retrieved from OP-FTIR spectra acquired over a 1 km optical path with reasonable detection limits on the order of 10 {micro}g{center_dot}m{sup {minus}3} for aerosols with optical properties equivalent to water.

  15. Molecular Dynamics at Electrical- and Optical-Driven Phase Transitions: Time-Resolved Infrared Studies Using Fourier-Transform Spectrometers

    NASA Astrophysics Data System (ADS)

    Peterseim, Tobias; Dressel, Martin

    2016-06-01

    The time-dependent optical properties of molecular systems are investigated by step-scan Fourier-transform spectroscopy in order to explore the dynamics at phase transitions and molecular orientation in the milli- and microsecond range. The electrical switching of liquid crystals traced by vibrational spectroscopy reveals a rotation of the molecules with a relaxation time of 2 ms. The photo-induced neutral-ionic transition in TTF-CA takes place by a suppression of the dimerization in the ionic phase and creation of neutral domains. The time-dependent infrared spectra, employed to investigate the domain-wall dynamics, depend on temperature and laser pulse intensity; the relaxation of the spectra follows a stretched-exponential decay with relaxation times in the microsecond range strongly dependent on temperature and laser intensity. We present all details of the experimental setups and thoroughly discuss the technical challenges.

  16. Discrimination between Bacillus and Alicyclobacillus isolates in apple juice by Fourier transform infrared spectroscopy and multivariate analysis.

    PubMed

    Al-Holy, Murad A; Lin, Mengshi; Alhaj, Omar A; Abu-Goush, Mahmoud H

    2015-02-01

    Alicyclobacillus is a causative agent of spoilage in pasteurized and heat-treated apple juice products. Differentiating between this genus and the closely related Bacillus is crucially important. In this study, Fourier transform infrared spectroscopy (FT-IR) was used to identify and discriminate between 4 Alicyclobacillus strains and 4 Bacillus isolates inoculated individually into apple juice. Loading plots over the range of 1350 and 1700 cm(-1) reflected the most distinctive biochemical features of Bacillus and Alicyclobacillus. Multivariate statistical methods (for example, principal component analysis and soft independent modeling of class analogy) were used to analyze the spectral data. Distinctive separation of spectral samples was observed. This study demonstrates that FT-IR spectroscopy in combination with multivariate analysis could serve as a rapid and effective tool for fruit juice industry to differentiate between Bacillus and Alicyclobacillus and to distinguish between species belonging to these 2 genera.

  17. The Micro Fourier Transform Interferometer (muFTIR) - A New Field Spectrometer for Acquisition of Infrared Data of Natural Surfaces

    NASA Technical Reports Server (NTRS)

    Hook, Simon J.

    1995-01-01

    A lightweight, rugged, high-spectral-resolution interferometer has been built by Designs and Prototypes based on a set of specifications provided by the Jet Propulsion Laboratory and Dr. J. W. Salisbury (Johns Hopkins University). The instrument, the micro Fourier Transform Interferometer (mFTIR), permits the acquisition of infrared spectra of natural surfaces. Such data can be used to validate low and high spectral resolution data acquired remotely from aircraft and spacecraft in the 3-5 mm and 8-14 mm atmospheric window. The instrument has a spectral resolutions of 6 wavenumbers, weighs 16 kg including batteries and computer, and can be operated easily by two people in the field. Laboratory analysis indicates the instrument is spectrally calibrated to better than 1 wavenumber and the radiometric accuracy is <0.5 K if the radiances from the blackbodies used for calibration bracket the radiance from the sample.

  18. Fourier transform-infrared spectroscopy and Gas chromatography-mass spectroscopy: reliable techniques for analysis of Parthenium mediated vermicompost.

    PubMed

    Rajiv, P; Rajeshwari, Sivaraj; Venckatesh, Rajendran

    2013-12-01

    Fourier transform infrared spectroscopy (FT-IR) and Gas chromatography-mass spectroscopy have been carried out to investigate the chemical composition of Parthenium mediated vermicompost. Four different concentrations of Parthenium and cow dung mixtures were vermicomposted using the earthworms (Eudrilus eugeniae). FT-IR spectra reveal the absence of Parthenin toxin (sesquiterpene lactone) and phenols in vermicompost which was obtained from high concentration of cow dung mixed treatments. GC-MS analysis shows no phenolic compounds and predominant level of intermediate metabolites such as 4,8,12,16-Tetramethylheptadecan-4-olide (7.61%), 2-Pentadecanone, 6,10,14-trimethyl- (5.29%) and Methyl 16-methyl-heptadecanoate (4.69%) during the vermicomposting process. Spectral results indicated that Parthenin toxin and phenols can be eradicated via vermicomposting if mixed with appropriate quantity of cow dung.

  19. Photochemistry of a Puckered Ferracyclobutadiene in Liquid Solution Studied by Time-Resolved Fourier-Transform Infrared Spectroscopy.

    PubMed

    Torres-Alacan, Joel; Das, Ujjal; Wezisla, Boris; Straßmann, Martin; Filippou, Alexander C; Vöhringer, Peter

    2015-11-23

    Flash photolysis combined with step-scan and rapid-scan Fourier-transform infrared spectroscopy was carried out to explore the photochemistry of a puckered, quasi-square pyramidal ferracyclobutadiene, [Fe{κ(2) -C3 (NEt2 )3 }(CO)3 ]BF4 ([1]BF4 ), that features three additional carbonyl ligands in the metal coordination sphere. In liquid solution at room temperature, an excitation with λ=355 nm light resulted in the loss of one CO ligand, which is cleaved from a basal metal-coordination site. Within the time resolution of the experiment, a solvent molecule promptly refills the resultant vacancy at the coordinatively unsaturated metal center. In the weakly interacting liquid, dichloromethane, the counterion of the complex is subsequently able to substitute the solvent in the coordination sphere of the iron center, thereby forming as a stable product a neutral dicarbonyl tetrafluoroborato iron(0) species containing a four-membered ferracycle.

  20. Proteoglycan concentrations in healthy and diseased articular cartilage by Fourier transform infrared imaging and principal component regression

    NASA Astrophysics Data System (ADS)

    Yin, Jianhua; Xia, Yang

    2014-12-01

    Fourier transform infrared imaging (FTIRI) combining with principal component regression (PCR) analysis were used to determine the reduction of proteoglycan (PG) in articular cartilage after the transection of the anterior cruciate ligament (ACL). A number of canine knee cartilage sections were harvested from the meniscus-covered and meniscus-uncovered medial tibial locations from the control joints, the ACL joints at three time points after the surgery, and their contralateral joints. The PG loss in the ACL cartilage was related positively to the durations after the surgery. The PG loss in the contralateral knees was less than that of the ACL knees. The PG loss in the meniscus-covered cartilage was less than that of the meniscus-uncovered tissue in both ACL and contralateral knees. The quantitative mapping of PG loss could monitor the disease progression and repair processes in arthritis.

  1. Fourier transform-infrared spectroscopy and Gas chromatography-mass spectroscopy: Reliable techniques for analysis of Parthenium mediated vermicompost

    NASA Astrophysics Data System (ADS)

    Rajiv, P.; Rajeshwari, Sivaraj; Venckatesh, Rajendran

    2013-12-01

    Fourier transform infrared spectroscopy (FT-IR) and Gas chromatography-mass spectroscopy have been carried out to investigate the chemical composition of Parthenium mediated vermicompost. Four different concentrations of Parthenium and cow dung mixtures were vermicomposted using the earthworms (Eudrilus eugeniae). FT-IR spectra reveal the absence of Parthenin toxin (sesquiterpene lactone) and phenols in vermicompost which was obtained from high concentration of cow dung mixed treatments. GC-MS analysis shows no phenolic compounds and predominant level of intermediate metabolites such as 4,8,12,16-Tetramethylheptadecan-4-olide (7.61%), 2-Pentadecanone, 6,10,14-trimethyl- (5.29%) and Methyl 16-methyl-heptadecanoate (4.69%) during the vermicomposting process. Spectral results indicated that Parthenin toxin and phenols can be eradicated via vermicomposting if mixed with appropriate quantity of cow dung.

  2. Method of spectral subtraction of gas-phase Fourier transform infrared (FT-IR) spectra by minimizing the spectrum length.

    PubMed

    Kozlov, Denis; Besov, Alexey

    2011-08-01

    A new method of spectral subtraction for gas-phase Fourier transform infrared (FT-IR) spectra was developed for long-path gas measurements. The method is based on minimization of the length of the spectrum that results from subtracting the spectrum of an individual component of a gas mixture (water, CO(2), etc.) from the experimental spectrum of the mixture. For this purpose a subtraction coefficient (k(min)) is found for which the length of the resulting spectrum is minimized. A mathematical simulation with two Lorentzian absorption bands was conducted and the limits of application for the proposed method were determined. Two experimental examples demonstrate that a successful result could be achieved in the case when the subtrahend spectrum contains a number of narrow absorption bands (such as the spectrum of water vapor). PMID:21819781

  3. Quantitative analysis of sodium carbonate and sodium bicarbonate in solid mixtures using Fourier transform infrared spectroscopy (FT-IR).

    PubMed

    Joshi, Shailesh; Kalyanasundaram, Sivasubramanian; Balasubramanian, Venkatraman

    2013-08-01

    An analytical methodology is proposed based on constant ratio and absorbance correction methods to quantify sodium carbonate, Na₂CO₃ (1450 cm⁻¹), and sodium bicarbonate, NaHCO₃ (1000 cm⁻¹, 1923 cm⁻¹), in solid mixtures using Fourier transform infrared (FT-IR) spectroscopy. Potassium ferricyanide, K₃Fe(CN)₆ (2117cm⁻¹), was used as an internal standard to get characteristic parameters. NaHCO₃ was quantified using the constant ratio method. Spectral interference of NaHCO₃ in Na₂CO₃ (1450 cm⁻¹) was corrected using the absorbance correction method. The corrected absorbance was successfully applied to quantify Na₂CO₃ (1450 cm⁻¹) in the mixture using the constant ratio method. The results obtained for simulated samples were satisfactory (relative standard deviation less than 7%) for all samples.

  4. The potential of passive-remote Fourier transform infrared (FTIR) spectroscopy to detect organic emissions under the Clean Air Act

    SciTech Connect

    Demirgian, J.C.; Hammer, C.L. ); Kroutil, R.T. )

    1992-01-01

    The Clean Air Act of 1990 regulates the emission of 198 air toxics. Currently, there is no existing technology by which a regulatory agency can independently determine if a facility is in compliance. We have successfully tested the ability of passive-remote Fourier transform infrared (FTIR) spectroscopy to detect chemical plumes released in the field. Additional laboratory releases demonstrated that FTIR spectroscopy can detect target analytes in mixtures containing components which have overlapping absorbances. The FTIR spectrometer was able to identify and quantify each component released with an average quantitative error of less than 20% using partial least squares (PLS) analysis and 40% using classical least squares analysis (CLS) when calibration files containing pure components and mixtures were used. Calibration files containing only pure analytes resulted in CLS outperforming PLS analyses.

  5. The potential of passive-remote Fourier transform infrared (FTIR) spectroscopy to detect organic emissions under the Clean Air Act

    SciTech Connect

    Demirgian, J.C.; Hammer, C.L.; Kroutil, R.T.

    1992-07-01

    The Clean Air Act of 1990 regulates the emission of 198 air toxics. Currently, there is no existing technology by which a regulatory agency can independently determine if a facility is in compliance. We have successfully tested the ability of passive-remote Fourier transform infrared (FTIR) spectroscopy to detect chemical plumes released in the field. Additional laboratory releases demonstrated that FTIR spectroscopy can detect target analytes in mixtures containing components which have overlapping absorbances. The FTIR spectrometer was able to identify and quantify each component released with an average quantitative error of less than 20% using partial least squares (PLS) analysis and 40% using classical least squares analysis (CLS) when calibration files containing pure components and mixtures were used. Calibration files containing only pure analytes resulted in CLS outperforming PLS analyses.

  6. Fourier transform infrared identification of the ν5(σu) fundamental of SiC5Si.

    PubMed

    Lê, T H; Rittby, C M L; Graham, W R M

    2014-07-28

    The Fourier transform infrared spectrum of SiC5Si was observed by trapping the vapor from the Nd:YAG laser ablation of sintered Si/C rods in solid Ar at ∼20 K. Measurements of (13)C and (29,30)Si isotopic shifts have enabled the identification of the ν5(σu) vibrational fundamental of the linear isomer of SiC5Si at 1590.8 ± 0.2 cm(-1). The results are in excellent agreement with the predictions of density functional theory calculations at the B3LYP/cc-pVDZ level. A second fundamental, ν4(σu), can only be tentatively identified at 2021.0 cm(-1), because its isotopic shifts are overlapped by absorptions from other species.

  7. In situ concentration monitoring in a vertical OMVPE reactor by fiber-optics-based Fourier transform infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Salim, S.; Wang, C. A.; Driver, R. D.; Jensen, K. F.

    1996-12-01

    We describe fiber-optics-based Fourier transform infrared (FOB-FTIR) spectroscopy for in situ monitoring of input partial pressures of organometallic precursors in a vertical rotating-disk organometallic vapor phase epitaxy reactor. Detection limits as low as 0.05 Torr for trimethylgallium and 0.006 Torr for tritertiarybutylaluminum (TTBAl) are achieved using a 1 s scan time, which are comparable to established ultrasonic measurements. In addition, the FOB-FTIR approach has the ability to detect parasitic Lewis acid-base interactions between organometallic precursors, as demonstrated for in situ measurements of TTBAl mixed with arsine, trimethylantimony or triethylantimony. Such observations are shown to provide insight into unexpected results in epitaxial growth.

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

    PubMed

    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.

  9. Fourier transform infrared imaging and microscopy studies of Pinus radiata pulps regarding the simultaneous saccharification and fermentation process.

    PubMed

    Castillo, Rosario del P; Araya, Juan; Troncoso, Eduardo; Vinet, Silenne; Freer, Juanita

    2015-03-25

    The distribution and chemical patterns of lignocellulosic components at microscopic scale and their effect on the simultaneous saccharification and fermentation process (SSF) in the production of bioethanol from Pinus radiata pulps were analyzed by the application of diverse microscopical techniques, including scanning electronic microscopy (SEM), confocal laser scanning microscopy (CLSM) and attenuated total reflectance (ATR) - Fourier transform infrared microspectroscopy. This last technique was accompanied with multivariate methods, including principal component analysis (PCA) and multivariate curve resolution with alternating least squares (MCR-ALS) to evaluate the distribution patterns and to generate pure spectra of the lignocellulosic components of fibers. The results indicate that the information obtained by the techniques is complementary (ultrastructure, confocality and chemical characterization) and that the distribution of components affects the SSF yield, identifying lignin coalescence droplets as a characteristic factor to increase the SSF yield. Therefore, multivariate analysis of the infrared spectra enabled the in situ identification of the cellulose, lignin and lignin-carbohydrates arrangements. These techniques could be used to investigate the lignocellulosic components distribution and consequently their recalcitrance in many applications where minimal sample manipulation and microscale chemical information is required.

  10. Polarized Fourier transform infrared spectroscopy of bacteriorhodopsin. Transmembrane alpha helices are resistant to hydrogen/deuterium exchange

    SciTech Connect

    Earnest, T.N.; Herzfeld, J.; Rothschild, K.J. )

    1990-12-01

    The secondary structure of bacteriorhodopsin has been investigated by polarized Fourier transform infrared spectroscopy combined with hydrogen/deuterium exchange, isotope labeling and resolution enhancement methods. Oriented films of purple membrane were measured at low temperature after exposure to H2O or D2O. Resolution enhancement techniques and isotopic labeling of the Schiff base were used to assign peaks in the amide I region of the spectrum. alpha-helical structure, which exhibits strong infrared dichroism, undergoes little H/D exchange, even after 48 h of D2O exposure. In contrast, non-alpha-helical structure, which exhibits little dichroism, undergoes rapid H/D exchange. A band at 1,640 cm-1, which has previously been assigned to beta-sheet structure, is found to be due in part to the C = N stretching vibration of protonated Schiff base of the retinylidene chromophore. We conclude that the membrane spanning regions of bR consist predominantly of alpha-helical structure whereas most beta-type structure is located in surface regions directly accessible to water.

  11. Separation and determination of estrogen in the water environment by high performance liquid chromatography-fourier transform infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Zheng, Bei; Li, Wentao; Li, Hongyan; Liu, Lin; Lei, Pei; Ge, Xiaopeng; Yu, Zhiyong; Zhou, Yiqi

    2016-08-01

    The components for connecting high-performance liquid chromatography (HPLC) with Fourier-transform infrared spectroscopy (FTIR) were investigated to determine estrogen in the water environment, including heating for atomization, solvent removal, sample deposition, drive control, spectrum collection, chip swap, cleaning and drying. Results showed that when the atomization temperature was increased to 388 K, the interference of mobile phase components (methanol, H2O, acetonitrile, and NaH2PO4) were completely removed in the IR measurement of estrogen, with 0.999 of similarity between IR spectra obtained after separation and corresponding to the standard IR spectra. In experiments with varying HPLC injection volumes, high similarity for IR spectra was obtained at 20 ul injection volume at 0.01 mg/L BPA while a useful IR spectrum for 10 ng/L BPA was obtained at 80 ul injection volume. In addition, estrogen concentrations in the natural water samples were calculated semi-quantitatively from the peak intensities of IR spectrum in the mid-infrared region.

  12. Microfluidic Approaches to Synchrotron Radiation-Based Fourier Transform Infrared (SR-FTIR) Spectral Microscopy of Living Biosystems

    PubMed Central

    Loutherback, Kevin; Birarda, Giovanni; Chen, Liang; Holman, Hoi-Ying N.

    2016-01-01

    A long-standing desire in biological and biomedical sciences is to be able to probe cellular chemistry as biological processes are happening inside living cells. Synchrotron radiation-based Fourier transform infrared (SR-FTIR) spectral microscopy is a label-free and nondestructive analytical technique that can provide spatiotemporal distributions and relative abundances of biomolecules of a specimen by their characteristic vibrational modes. Despite great progress in recent years, SR-FTIR imaging of living biological systems remains challenging because of the demanding requirements on environmental control and strong infrared absorption of water. To meet this challenge, microfluidic devices have emerged as a method to control the water thickness while providing a hospitable environment to measure cellular processes and responses over many hours or days. This paper will provide an overview of microfluidic device development for SR-FTIR imaging of living biological systems, provide contrast between the various techniques including closed and open-channel designs, and discuss future directions of development within this area. Even as the fundamental science and technological demonstrations develop, other ongoing issues must be addressed; for example, choosing applications whose experimental requirements closely match device capabilities, and developing strategies to efficiently complete the cycle of development. These will require imagination, ingenuity and collaboration. PMID:26732243

  13. Fourier Transform Infrared Spectroscopy (FTIR) and Multivariate Analysis for Identification of Different Vegetable Oils Used in Biodiesel Production

    PubMed Central

    Mueller, Daniela; Ferrão, Marco Flôres; Marder, Luciano; da Costa, Adilson Ben; de Cássia de Souza Schneider, Rosana

    2013-01-01

    The main objective of this study was to use infrared spectroscopy to identify vegetable oils used as raw material for biodiesel production and apply multivariate analysis to the data. Six different vegetable oil sources—canola, cotton, corn, palm, sunflower and soybeans—were used to produce biodiesel batches. The spectra were acquired by Fourier transform infrared spectroscopy using a universal attenuated total reflectance sensor (FTIR-UATR). For the multivariate analysis principal component analysis (PCA), hierarchical cluster analysis (HCA), interval principal component analysis (iPCA) and soft independent modeling of class analogy (SIMCA) were used. The results indicate that is possible to develop a methodology to identify vegetable oils used as raw material in the production of biodiesel by FTIR-UATR applying multivariate analysis. It was also observed that the iPCA found the best spectral range for separation of biodiesel batches using FTIR-UATR data, and with this result, the SIMCA method classified 100% of the soybean biodiesel samples. PMID:23539030

  14. Concentration profiles of collagen and proteoglycan in articular cartilage by Fourier transform infrared imaging and principal component regression

    NASA Astrophysics Data System (ADS)

    Yin, Jianhua; Xia, Yang; Lu, Mei

    2012-03-01

    Fourier-transform infrared imaging (FT-IRI) technique with the principal component regression (PCR) method was used to quantitatively determine the 2D images and the depth-dependent concentration profiles of two principal macromolecular components (collagen and proteoglycan) in articular cartilage. Ten 6 μm thick sections of canine humeral cartilage were imaged at a pixel size of 6.25 μm in FT-IRI. The infrared spectra extracted from FT-IRI experiments were imported into a PCR program to calculate the quantitative distributions of both collagen and proteoglycan in dry cartilage, which were subsequently converted into the wet-weight based concentration profiles. The proteoglycan profiles by FT-IRI and PCR significantly correlated in linear regression with the proteoglycan profiles by the non-destructive μMRI (the goodness-of-fit 0.96 and the Pearson coefficient 0.98). Based on these concentration relationships, the concentration images of collagen and proteoglycan in both healthy and lesioned articular cartilage were successfully constructed two dimensionally. The simultaneous construction of both collagen and proteoglycan concentration images demonstrates that this combined imaging and chemometrics approach could be used as a sensitive tool to accurately resolve and visualize the concentration distributions of macromolecules in biological tissues.

  15. Characterization of the basidiomycetes Thelephora ganbajun Zang and Termitomyces albuminosus (Berk.) Heim by Fourier transform infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Liu, Gang; Song, Dingshan; Liu, Jian-hong; Zhao, Dezhang; Zhou, Yilan; Ou, Jiaming; Sun, Shizhong

    2006-09-01

    The basidiomycetes Thelephora ganbajun Zang and Termitomyces albuminosus (Berk.) Heim are two of the most favorite edible mushrooms in Yunnan Province, Southwest of China. In this paper, Fourier transform infrared speciroseopy (FTIR) was used to characterize the fruiting bodies of the two wild growing edible mushrooms. The results show that each mushroom has its characteristic infrared spectrum, in which the major peaks are attributed to proteins and polysaccharides. The spectra indicate that the poiysaccharides of the two mushrooms contain, both. α- and β-glycosidic linkage. A characteristic band of Thelephora ganbajun is an obvious band at about 1763 cm -1, which indicates that the mushroom contain oil. Differences are observed in the spectra of different parts of the fruiting body of Termitomyces albuminosus. According to the differences of the characteristic spectra peaks and absorbance ratios, the different parts of mushroom can be discriminated. The results suggest that the different species of mushrooms might be identified by the vibrational spectral features of the different parts of the fruiting bodies of mushrooms.

  16. Breadboard of a Fourier-transform spectrometer for the radiation explorer in the far infrared atmospheric mission.

    PubMed

    Palchetti, Luca; Bianchini, Giovanni; Castagnoli, Francesco; Carli, Bruno; Serio, Carmine; Esposito, Francesco; Cuomo, Vincenzo; Rizzi, Rolando; Maestri, Tiziano

    2005-05-10

    In preparation for a possible space mission, a breadboard version named REFIR-BB of the Radiation Explorer in the Far Infrared (REFIR) instrument has been built. The REFIR is a Fourier-transform spectrometer with a new optical layout operating in the spectral range 100-1100 cm(-1) with a resolution of 0.5 cm(-1), a 7-s acquisition time, and a signal-to-noise ratio of better than 100. Its mission is the spectral measurement in the far infrared of the Earth's outgoing emission, with particular attention to the long-wavelength spectral region, which is not covered by either current or planned space missions. This measurement is of great importance for deriving an accurate estimate of the radiation budget in both clear and cloudy conditions. The REFIR-BB permits the trade-off among all instrument parameters to be studied, the optical layout to be tested, and the data-acquisition strategy to be optimized. The breadboard could be used for high-altitude ground-based campaigns or could be flown for test flights on aircraft or balloon stratospheric platforms. The breadboard's design and the experimental results are described, with particular attention to the acquisition strategy and characterization of the interferometer. Tests were performed both in laboratory conditions and in vacuum. Notwithstanding a loss of efficiency above 700 cm(-1) caused by the poor performance of the photolithographic polarizers used as beam splitters, the results demonstrate the feasibility of using the spectrometer for space applications.

  17. Direct determination of rosmarinic acid in Lamiaceae herbs using diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and chemometrics.

    PubMed

    Saltas, Dimitrios; Pappas, Christos S; Daferera, Dimitra; Tarantilis, Petros A; Polissiou, Moschos G

    2013-04-01

    For the determination of rosmarinic acid (RA) directly in pulverized plant material, a method is developed using diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) without any physicochemical pretreatment of samples. The RA content of 11 samples of eight different Lamiaceae herbs, as determined by high performance liquid chromatography (HPLC), varied between 86 ± 1 mg/g (in lemon balm) and 12.0 ± 0.8 mg/g (in hyssop) of dried plant material. The 11 samples and 50 other additional samples, which were prepared by mixing initial samples with KBr, were measured using DRIFTS. The second derivative of the spectral region 1344-806 cm(-1) was used and the corresponding data were analyzed using partial least squares (PLS) regression. The correlation between infrared spectral analysis and HPLC measurements shows that the DRIFTS method is sufficiently accurate, simple, and rapid. The RA content of the 11 Lamiaceae samples determined by DRIFTS ranged from 81 ± 4 mg/g (in lemon balm) to 12 ± 3 mg/g (in hyssop) of dried plant material. PMID:23496773

  18. Quantitative interpretation of Fourier-transform infrared spectoscopic data from a size--exlusion chromatorgraphy solvent- evaporation interface.

    PubMed

    Karami, A; Balke, S T; Schunk, T C

    2001-03-01

    Quantitative evaluation of polymer composition across the SEC chromatogram can provide more accurate characterization of heterogeneous polymer samples for problem solving and for material specification. To this end Fourier-transform infrared spectroscopy (FTIR) with solvent-evaporation interfaces has become a very powerful detector for size-exclusion chromatography (SEC). The solvent-evaporation interface removes the mobile phase at the exit of the chromatograph and deposits the separated molecular sizes as polymer films on infrared transparent substrates. Quantitative interpretation of the FTIR spectra obtained from these films has recently been found to be best accomplished by using partial least squares. In this paper, polystyrene and poly(methylmethacrylate), alone, as blends, and a copolymer were analyzed in a SEC equipped with an evaporative interface. Molecular weight effects, wavelength selection, the effect of averaging spectra on results, and selection of the best data preprocessing method were investigated. General methods of evaluating these variables were developed to arrive at conditions for this particular "model" situation in order to provide a basis for the analysis of more complex polymers.

  19. Concentration determination of collagen and proteoglycan in bovine nasal cartilage by Fourier transform infrared imaging and PLS

    NASA Astrophysics Data System (ADS)

    Zhang, Xuexi; Xiao, Zhi-Yan; Yin, Jianhua; Xia, Yang

    2014-09-01

    Fourier transform infrared imaging (FTIRI) combined with chemometrics can be used to detect the structure of bio-macromolecule, measure the concentrations of some components, and so on. In this study, FTIRI with Partial Least-Squares (PLS) regression was applied to study the concentration of two main components in bovine nasal cartilage (BNC), collagen and proteoglycan. An infrared spectrum library was built by mixing the collagen and chondroitin 6-sulfate (main of proteoglycan) at different ratios. Some pretreatments are needed for building PLS model. FTIR images were collected from BNC sections at 6.25μm and 25μm pixel size. The spectra extracted from BNC-FTIR images were imported into the PLS regression program to predict the concentrations of collagen and proteoglycan. These PLS-determined concentrations are agreed with the result in our previous work and biochemical analytical results. The prediction shows that the concentrations of collagen and proteoglycan in BNC are comparative on the whole. However, the concentration of proteoglycan is a litter higher than that of collagen, to some extent.

  20. Monitoring ultraviolet (UV) radiation inactivation of Cronobacter sakazakii in dry infant formula using Fourier transform infrared spectroscopy.

    PubMed

    Liu, Qian; Lu, Xiaonan; Swanson, Barry G; Rasco, Barbara A; Kang, Dong-Hyun

    2012-01-01

    Cronobacter sakazakii is an opportunistic pathogen associated with dry infant formula presenting a high risk to low birth weight neonates. The inactivation of C. sakazakii in dry infant formula by ultraviolet (UV) radiation alone and combined with hot water treatment at temperatures of 55, 60, and 65 °C were applied in this study. UV radiation with doses in a range from 12.1 ± 0.30 kJ/m² to 72.8 ± 1.83 kJ/m² at room temperature demonstrated significant inactivation of C. sakazakii in dry infant formula (P < 0.05). UV radiation combining 60 °C hot water treatment increased inactivation of C. sakazakii cells significantly (P < 0.05) in reconstituted infant formula. Significant effects of UV radiation on C. sakazakii inactivation kinetics (D value) were not observed in infant formula reconstituted in 55 and 65 °C water (P > 0.05). The inactivation mechanism was investigated using vibrational spectroscopy. Infrared spectroscopy detected significant stretching mode changes of macromolecules on the basis of spectral features, such as DNA, proteins, and lipids. Minor changes on cell membrane composition of C. sakazakii under UV radiation could be accurately and correctly monitored by infrared spectroscopy coupled with 2nd derivative transformation and principal component analysis.

  1. Structural control of surface layer proteins at electrified interfaces investigated by in situ Fourier transform infrared spectroscopy.

    PubMed

    Zafiu, Christian; Trettenhahn, Günter; Pum, Dietmar; Sleytr, Uwe Bernd; Kautek, Wolfgang

    2011-08-01

    In situ Fourier Transform Infrared (FTIR) Spectroscopy complemented by Electrochemical Quartz Microbalance (EQMB) investigations allowed a detailed insight into the influence of the electrode potential on competing adsorption processes and bonding mechanisms of buffer ions and S-layer protein molecules of Lysinibacillus sphaericus CCM2177 at an electrified liquid/gold interface. The S-layer proteins adsorb on gold polarized positively of the point of zero charge by displacing perchlorate anions in the Helmholtz plane by their carboxylate groups. This is indicated by an increase of the peptide and carboxylate infrared absorption signals accompanied by a decrease of the perchlorate signal. S-layers interlinked laterally with Ca(2+) ions, positive of the point of zero charge, resulted in the formation of a crystalline layer participating in the Helmholtz layer. In contrast to the absence of the Ca(2+)-linkers, S-layers remain structurally intact also in the negative polarization domain where the Helmholtz layer is solely sustained by mainly solvated cations without participation of the negatively charged protein carboxylate functions.

  2. Identification of fungal phytopathogens using Fourier transform infrared-attenuated total reflection spectroscopy and advanced statistical methods

    NASA Astrophysics Data System (ADS)

    Salman, Ahmad; Lapidot, Itshak; Pomerantz, Ami; Tsror, Leah; Shufan, Elad; Moreh, Raymond; Mordechai, Shaul; Huleihel, Mahmoud

    2012-01-01

    The early diagnosis of phytopathogens is of a great importance; it could save large economical losses due to crops damaged by fungal diseases, and prevent unnecessary soil fumigation or the use of fungicides and bactericides and thus prevent considerable environmental pollution. In this study, 18 isolates of three different fungi genera were investigated; six isolates of Colletotrichum coccodes, six isolates of Verticillium dahliae and six isolates of Fusarium oxysporum. Our main goal was to differentiate these fungi samples on the level of isolates, based on their infrared absorption spectra obtained using the Fourier transform infrared-attenuated total reflection (FTIR-ATR) sampling technique. Advanced statistical and mathematical methods: principal component analysis (PCA), linear discriminant analysis (LDA), and k-means were applied to the spectra after manipulation. Our results showed significant spectral differences between the various fungi genera examined. The use of k-means enabled classification between the genera with a 94.5% accuracy, whereas the use of PCA [3 principal components (PCs)] and LDA has achieved a 99.7% success rate. However, on the level of isolates, the best differentiation results were obtained using PCA (9 PCs) and LDA for the lower wavenumber region (800-1775 cm-1), with identification success rates of 87%, 85.5%, and 94.5% for Colletotrichum, Fusarium, and Verticillium strains, respectively.

  3. Fiber-optic Fourier transform infrared spectroscopy for remote label-free sensing of medical device surface contamination

    NASA Astrophysics Data System (ADS)

    Hassan, Moinuddin; Tan, Xin; Welle, Elissa; Ilev, Ilko

    2013-05-01

    As a potential major source of biochemical contamination, medical device surfaces are of critical safety concerns in the clinical practice and public health. The development of innovative sensing methods for accurate and real-time detection of medical device surface contamination is essential to protect patients from high risk infection. In this paper, we demonstrate an alternative fiber-optic Fourier Transform Infrared (FTIR) spectroscopy based sensing approach for remote, non-contact, and label-free detection of biochemical contaminants in the mid-infrared (mid-IR) region. The sensing probe is designed using mid-IR hollow fibers and FTIR measurements are carried out in reflection mode. Bovine Serum Albumin (BSA) and bacterial endotoxin of different concentrations under thoroughly dry condition are used to evaluate the detection sensitivity. The devised system can identify ≤0.0025% (≤4 × 1011 molecules) BSA and 0.5% (0.5 EU/ml) endotoxin concentration. The developed sensing approach may be applied to detect various pathogens that pose public health threats.

  4. Separation and determination of estrogen in the water environment by high performance liquid chromatography-fourier transform infrared spectroscopy.

    PubMed

    Zheng, Bei; Li, Wentao; Li, Hongyan; Liu, Lin; Lei, Pei; Ge, Xiaopeng; Yu, Zhiyong; Zhou, Yiqi

    2016-01-01

    The components for connecting high-performance liquid chromatography (HPLC) with Fourier-transform infrared spectroscopy (FTIR) were investigated to determine estrogen in the water environment, including heating for atomization, solvent removal, sample deposition, drive control, spectrum collection, chip swap, cleaning and drying. Results showed that when the atomization temperature was increased to 388 K, the interference of mobile phase components (methanol, H2O, acetonitrile, and NaH2PO4) were completely removed in the IR measurement of estrogen, with 0.999 of similarity between IR spectra obtained after separation and corresponding to the standard IR spectra. In experiments with varying HPLC injection volumes, high similarity for IR spectra was obtained at 20 ul injection volume at 0.01 mg/L BPA while a useful IR spectrum for 10 ng/L BPA was obtained at 80 ul injection volume. In addition, estrogen concentrations in the natural water samples were calculated semi-quantitatively from the peak intensities of IR spectrum in the mid-infrared region. PMID:27577974

  5. Direct determination of rosmarinic acid in Lamiaceae herbs using diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and chemometrics.

    PubMed

    Saltas, Dimitrios; Pappas, Christos S; Daferera, Dimitra; Tarantilis, Petros A; Polissiou, Moschos G

    2013-04-01

    For the determination of rosmarinic acid (RA) directly in pulverized plant material, a method is developed using diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) without any physicochemical pretreatment of samples. The RA content of 11 samples of eight different Lamiaceae herbs, as determined by high performance liquid chromatography (HPLC), varied between 86 ± 1 mg/g (in lemon balm) and 12.0 ± 0.8 mg/g (in hyssop) of dried plant material. The 11 samples and 50 other additional samples, which were prepared by mixing initial samples with KBr, were measured using DRIFTS. The second derivative of the spectral region 1344-806 cm(-1) was used and the corresponding data were analyzed using partial least squares (PLS) regression. The correlation between infrared spectral analysis and HPLC measurements shows that the DRIFTS method is sufficiently accurate, simple, and rapid. The RA content of the 11 Lamiaceae samples determined by DRIFTS ranged from 81 ± 4 mg/g (in lemon balm) to 12 ± 3 mg/g (in hyssop) of dried plant material.

  6. Feasibility study on chemometric discrimination of roasted Arabica coffees by solvent extraction and Fourier transform infrared spectroscopy.

    PubMed

    Wang, Niya; Fu, Yucheng; Lim, Loong-Tak

    2011-04-13

    In this feasibility study, Fourier transform infrared (FTIR) spectroscopy and chemometric analysis were adopted to discriminate coffees from different geographical origins and of different roasting degrees. Roasted coffee grounds were extracted using two methods: (1) solvent alone (dichloromethane, ethyl acetate, hexane, acetone, ethanol, or acetic acid) and (2) coextraction using a mixture of equal volume of the solvent and water. Experiment results showed that the coextraction method resulted in cleaner extract and provided a greater amount of spectral information, which was important for sample discrimination. Principal component analysis of infrared spectra of ethyl acetate extracts for dark and medium roast coffees showed separated clusters according to their geographical origins and roast degrees. Classification models based on soft independent modeling of class analogy analysis were used to classify different coffee samples. Coffees from four different countries, which were roasted to dark, were 100% correctly classified when ethyl acetate was used as a solvent. The FTIR-chemometric technique developed here may serve as a rapid tool for discriminating geographical origin of roasted coffees. Future studies involving green coffee beans and the use of larger sample size are needed to further validate the robustness of this technique. PMID:21381653

  7. Separation and determination of estrogen in the water environment by high performance liquid chromatography-fourier transform infrared spectroscopy

    PubMed Central

    Zheng, Bei; Li, Wentao; Li, Hongyan; Liu, Lin; Lei, Pei; Ge, Xiaopeng; Yu, Zhiyong; Zhou, Yiqi

    2016-01-01

    The components for connecting high-performance liquid chromatography (HPLC) with Fourier-transform infrared spectroscopy (FTIR) were investigated to determine estrogen in the water environment, including heating for atomization, solvent removal, sample deposition, drive control, spectrum collection, chip swap, cleaning and drying. Results showed that when the atomization temperature was increased to 388 K, the interference of mobile phase components (methanol, H2O, acetonitrile, and NaH2PO4) were completely removed in the IR measurement of estrogen, with 0.999 of similarity between IR spectra obtained after separation and corresponding to the standard IR spectra. In experiments with varying HPLC injection volumes, high similarity for IR spectra was obtained at 20 ul injection volume at 0.01 mg/L BPA while a useful IR spectrum for 10 ng/L BPA was obtained at 80 ul injection volume. In addition, estrogen concentrations in the natural water samples were calculated semi-quantitatively from the peak intensities of IR spectrum in the mid-infrared region. PMID:27577974

  8. [Analysis of Spirulina powder by Fourier transform infrared spectroscopy and calculation of protein content].

    PubMed

    Liu, Hai-Jing; Xu, Chang-Hua; Li, Wei-Ming; Wang, Feng; Zhou, Qun; Li, An; Zhao, Yue-Liang; Ha, Yi-Ming; Sun, Su-Qin

    2013-04-01

    Spirulina, Spirulina powder and dextrin standard were analyzed and identified by Infrared (IR) spectroscopy. The main components, protein (1 657 and 1 537 cm(-1)) and carbohydrate (1 069 and 1054 cm(-1)), had distinct fingerprint characteristics of IR spectra. By comparing the IR spectra of Spirulina, Spirulina powder and dextrin standard, the dominant nutrition in Spirulina powder was identified as protein and carbohydrate. The dominant accessory added in Spirulina powder was dextrin. Comparing the IR spectra of Spirulina powder from 28 different factories and figuring out the correlation provides the information about the amount of accessory. A standard curve of the ratio of absorption peak intensities to protein content was constructed to accurately determine the amount of protein in Spirulina powder.

  9. Analyzing Strawberry Spoilage via its Volatile Compounds Using Longpath Fourier Transform Infrared Spectroscopy

    PubMed Central

    Dong, Daming; Zhao, Chunjiang; Zheng, Wengang; Wang, Wenzhong; Zhao, Xiande; Jiao, Leizi

    2013-01-01

    The volatile compounds from fruits vary based on the spoilage stage. We used FTIR spectroscopy to analyze and to attempt to identify the spoilage process of strawberries. To enhance the sensitivity of the measuring system, we increased the optical pathlength by using multi-reflecting mirrors. The volatile compounds that were vaporized from strawberries in different spoilage stages were tested. We analyzed the spectra and found that the concentrations of esters, alcohols, ethylene, and similar compounds changed with deterioration. The change patterns of the infrared spectra for the volatiles were further examined using 2D correlation spectroscopy. We analyzed the spectral data using PCA and were able to distinguish the fresh, slightly spoiled strawberries from the seriously spoiled strawberries. This study demonstrates that FTIR is an effective tool for monitoring strawberry spoilage and for providing status alerts. PMID:24002611

  10. Temperature-sensitive junction transformations for mid-wavelength HgCdTe photovoltaic infrared detector arrays by laser beam induced current microscope

    SciTech Connect

    Qiu, Weicheng; Hu, Weida Lin, Tie; Yin, Fei; Zhang, Bo; Chen, Xiaoshuang; Lu, Wei; Cheng, Xiang'ai Wang, Rui

    2014-11-10

    In this paper, we report on the disappearance of the photosensitive area extension effect and the unusual temperature dependence of junction transformation for mid-wavelength, n-on-p HgCdTe photovoltaic infrared detector arrays. The n-type region is formed by B{sup +} ion implantation on Hg-vacancy-doped p-type HgCdTe. Junction transformations under different temperatures are visually captured by a laser beam induced current microscope. A physical model of temperature dependence on junction transformation is proposed and demonstrated by using numerical simulations. It is shown that Hg-interstitial diffusion and temperature activated defects jointly lead to the p-n junction transformation dependence on temperature, and the weaker mixed conduction compared with long-wavelength HgCdTe photodiode contributes to the disappearance of the photosensitive area extension effect in mid-wavelength HgCdTe infrared detector arrays.

  11. TRANSFORMATION

    SciTech Connect

    LACKS,S.A.

    2003-10-09

    Transformation, which alters the genetic makeup of an individual, is a concept that intrigues the human imagination. In Streptococcus pneumoniae such transformation was first demonstrated. Perhaps our fascination with genetics derived from our ancestors observing their own progeny, with its retention and assortment of parental traits, but such interest must have been accelerated after the dawn of agriculture. It was in pea plants that Gregor Mendel in the late 1800s examined inherited traits and found them to be determined by physical elements, or genes, passed from parents to progeny. In our day, the material basis of these genetic determinants was revealed to be DNA by the lowly bacteria, in particular, the pneumococcus. For this species, transformation by free DNA is a sexual process that enables cells to sport new combinations of genes and traits. Genetic transformation of the type found in S. pneumoniae occurs naturally in many species of bacteria (70), but, initially only a few other transformable species were found, namely, Haemophilus influenzae, Neisseria meningitides, Neisseria gonorrheae, and Bacillus subtilis (96). Natural transformation, which requires a set of genes evolved for the purpose, contrasts with artificial transformation, which is accomplished by shocking cells either electrically, as in electroporation, or by ionic and temperature shifts. Although such artificial treatments can introduce very small amounts of DNA into virtually any type of cell, the amounts introduced by natural transformation are a million-fold greater, and S. pneumoniae can take up as much as 10% of its cellular DNA content (40).

  12. Controllable Phase Transformation and Mid-infrared Emission from Er3+-Doped Hexagonal-/Cubic-NaYF4 Nanocrystals

    NASA Astrophysics Data System (ADS)

    Yang, Dandan; Chen, Dongdan; He, Huilin; Pan, Qiwen; Xiao, Quanlan; Qiu, Jianrong; Dong, Guoping

    2016-07-01

    The morphology of hexagonal phase NaYF4:Er3+ nanorods synthesized by hydrothermal method changed greatly after a continuing calcination, along with a phase transformation to cubic phase. Photoluminescence (PL) spectra indicated that mid-infrared (MIR) emission was obtained in both hexagonal and cubic phase NaYF4:Er3+ nanocrystals for the first time. And the MIR emission of NaYF4:Er3+ nanocrystals enhanced remarkably at higher calcination temperature. To prevent uncontrollable morphology from phase transformation, the cubic phase NaYF4:Er3+ nanospheres with an average size of ~100 nm were prepared via a co-precipitation method directly. In contrast, the results showed better morphology and size of cubic phase NaYF4:Er3+ nanocrystals have realized when calcined at different temperatures. And PL spectra demonstrated a more intense MIR emission in the cubic phase NaYF4:Er3+ nanocrystals with an increasing temperature. Besides, the MIR emission peak of Er3+ ions had an obvious splitting in cubic phase NaYF4. Therefore, cubic phase NaYF4:Er3+ nanospheres with more excellent MIR luminescent properties seems to provide a new material for nanocrystal-glass composites, which is expected to open a broad new field for the realization of MIR lasers gain medium.

  13. Determination of glucose and cellobiose dissolved in the ionic liquid 1-ethyl-3-methylimidazolium acetate using Fourier transform infrared spectroscopy.

    PubMed

    Kiefer, Johannes; Obert, Katharina; Fries, Jürgen; Bösmann, Andreas; Wasserscheid, Peter; Leipertz, Alfred

    2009-09-01

    The conversion of biogenic carbohydrate feedstock to chemicals or energy equivalents is a promising approach to solve the problem of limited fossil fuel reserves. Some concepts to accomplish these transformations are based on ionic liquids (ILs) due to their ability to dissolve biopolymers, such as cellulose, and even complex biopolymer mixtures, such as wood. However, concerning control of such conversions, a reliable tool for process analytics is required. In this paper we demonstrate the applicability of Fourier transform infrared (FT-IR) spectroscopy to perform quantitative concentration measurements of glucose and cellobiose as two examples of carbohydrates dissolved in the room-temperature ionic liquid [EMIM][OAc] (1-ethyl-3-methylimidazolium acetate). For this purpose, binary mixtures in the range 0-20 wt% have been studied. A previously developed method for the data analysis, which was based on the Beer-Lambert relation, has been universalized by employing empirical correlations between the measured quantity (i.e., extinction) and the carbohydrate concentration. In the entire spectral range under investigation (500-4000 cm(-1)) numerous individual wave-numbers have been identified, allowing quantitative measurements with high accuracy and precision.

  14. Controllable Phase Transformation and Mid-infrared Emission from Er3+-Doped Hexagonal-/Cubic-NaYF4 Nanocrystals

    PubMed Central

    Yang, Dandan; Chen, Dongdan; He, Huilin; Pan, Qiwen; Xiao, Quanlan; Qiu, Jianrong; Dong, Guoping

    2016-01-01

    The morphology of hexagonal phase NaYF4:Er3+ nanorods synthesized by hydrothermal method changed greatly after a continuing calcination, along with a phase transformation to cubic phase. Photoluminescence (PL) spectra indicated that mid-infrared (MIR) emission was obtained in both hexagonal and cubic phase NaYF4:Er3+ nanocrystals for the first time. And the MIR emission of NaYF4:Er3+ nanocrystals enhanced remarkably at higher calcination temperature. To prevent uncontrollable morphology from phase transformation, the cubic phase NaYF4:Er3+ nanospheres with an average size of ~100 nm were prepared via a co-precipitation method directly. In contrast, the results showed better morphology and size of cubic phase NaYF4:Er3+ nanocrystals have realized when calcined at different temperatures. And PL spectra demonstrated a more intense MIR emission in the cubic phase NaYF4:Er3+ nanocrystals with an increasing temperature. Besides, the MIR emission peak of Er3+ ions had an obvious splitting in cubic phase NaYF4. Therefore, cubic phase NaYF4:Er3+ nanospheres with more excellent MIR luminescent properties seems to provide a new material for nanocrystal-glass composites, which is expected to open a broad new field for the realization of MIR lasers gain medium. PMID:27453150

  15. Evaluation of an open-path fourier-transform infrared spectrometer for monitoring vehicle emissions over a suburban roadway intersection

    SciTech Connect

    Einfield, W.

    1997-05-01

    The ability of an open-path, fourier-transform infrared spectrometer to detect vehicle exhaust emissions approximately 3 meters above the roadway surface at a busy Albuquerque suburban intersection was evaluated in this study. Multiple measurements of carbon monoxide and carbon dioxide were carried out over pathlengths up to 100 meters during the morning commute period on multiple days in the summer of 1993. The carbon monoxide to fuel carbon ratio was computed from all spectral data in order to derive a vehicle fleet average ratio. The data were determined to be normally distributed with an overall carbon monoxide-fuel carbon ratio of 0.15. The 95% confidence interval about the mean was {+-} 0.009. Day-to-day variation of the mean ratio was determined to be on the order of 3%. The results indicate that anticipated reductions in carbon monoxide emissions following the implementation of a winter-season oxygenated fuel program could be reliably detected with an open-path fourier transform spectrometer. The periodic use of such an instrument may offer a cost-effective means of generating a city-wide carbon monoxide emission budget for vehicles sources.

  16. Controllable Phase Transformation and Mid-infrared Emission from Er(3+)-Doped Hexagonal-/Cubic-NaYF4 Nanocrystals.

    PubMed

    Yang, Dandan; Chen, Dongdan; He, Huilin; Pan, Qiwen; Xiao, Quanlan; Qiu, Jianrong; Dong, Guoping

    2016-01-01

    The morphology of hexagonal phase NaYF4:Er(3+) nanorods synthesized by hydrothermal method changed greatly after a continuing calcination, along with a phase transformation to cubic phase. Photoluminescence (PL) spectra indicated that mid-infrared (MIR) emission was obtained in both hexagonal and cubic phase NaYF4:Er(3+) nanocrystals for the first time. And the MIR emission of NaYF4:Er(3+) nanocrystals enhanced remarkably at higher calcination temperature. To prevent uncontrollable morphology from phase transformation, the cubic phase NaYF4:Er(3+) nanospheres with an average size of ~100 nm were prepared via a co-precipitation method directly. In contrast, the results showed better morphology and size of cubic phase NaYF4:Er(3+) nanocrystals have realized when calcined at different temperatures. And PL spectra demonstrated a more intense MIR emission in the cubic phase NaYF4:Er(3+) nanocrystals with an increasing temperature. Besides, the MIR emission peak of Er(3+) ions had an obvious splitting in cubic phase NaYF4. Therefore, cubic phase NaYF4:Er(3+) nanospheres with more excellent MIR luminescent properties seems to provide a new material for nanocrystal-glass composites, which is expected to open a broad new field for the realization of MIR lasers gain medium. PMID:27453150

  17. Miniature, Low-Power, Waveguide Based Infrared Fourier Transform Spectrometer for Spacecraft Remote Sensing

    NASA Technical Reports Server (NTRS)

    Hewagama, TIlak; Aslam, Shahid; Talabac, Stephen; Allen, John E., Jr.; Annen, John N.; Jennings, Donald E.

    2011-01-01

    Fourier transform spectrometers have a venerable heritage as flight instruments. However, obtaining an accurate spectrum exacts a penalty in instrument mass and power requirements. Recent advances in a broad class of non-scanning Fourier transform spectrometer (FTS) devices, generally called spatial heterodyne spectrometers, offer distinct advantages as flight optimized systems. We are developing a miniaturized system that employs photonics lightwave circuit principles and functions as an FTS operating in the 7-14 micrometer spectral region. The inteferogram is constructed from an ensemble of Mach-Zehnder interferometers with path length differences calibrated to mimic scan mirror sample positions of a classic Michelson type FTS. One potential long-term application of this technology in low cost planetary missions is the concept of a self-contained sensor system. We are developing a systems architecture concept for wide area in situ and remote monitoring of characteristic properties that are of scientific interest. The system will be based on wavelength- and resolution-independent spectroscopic sensors for studying atmospheric and surface chemistry, physics, and mineralogy. The self-contained sensor network is based on our concept of an Addressable Photonics Cube (APC) which has real-time flexibility and broad science applications. It is envisaged that a spatially distributed autonomous sensor web concept that integrates multiple APCs will be reactive and dynamically driven. The network is designed to respond in an event- or model-driven manner or reconfigured as needed.

  18. Ferrielectric liquid crystal subphase studied by polarized fourier-transform infrared spectroscopy

    PubMed

    Sigarev; Vij; Panarin; Goodby

    2000-08-01

    IR dichroism and the structure of a homogeneously aligned cell of a chiral smectic antiferroelectric liquid crystal (R)-1-methylheptyl 4-(4(')-dodecyloxybiphenyl-4-ylcarbonyloxy)-3-fluorobenzoate [with acronym (R)-12OF1M7] in a ferrielectric subphase in the temperature range between the antiferroelectric phase (also referred to as Fi2) and the smectic-C*(SmC*) phase are studied using polarized Fourier transform IR spectroscopy. The polarization dependencies of the absorbance for several characteristic bands are quantitatively analyzed for different stages of the electrically induced structural transformations in the sample, including the helix unwinding and the phase transition from the ferriphase to the SmC* phase. A qualitative similarity of the voltage dependence of the normalized angular shift of the IR absorbance profile for the "chiral" carbonyl band to that of the normalized macroscopic polarization is found. The voltage dependent dichroic properties of the sample are analyzed in terms of the molecular structure and unwinding of the helical structure under an external electric field. The rotational orientational biasing of the carbonyl groups around the long molecular axis is confirmed by the spectral data. The analysis of IR dichroic data for the field induced SmC* phase is used to determine the rotational orientational distributions for the carbonyl groups.

  19. [Study on Different Parts of Wild and Cultivated Gentiana Rigescens with Fourier Transform Infrared Spectroscopy].

    PubMed

    Shen, Yun-xia; Zhao, Yan-li; Zhang, Ji; Zuo, Zhi-tian; Wang, Yuan-zhong; Zhang, Qing-zhi

    2016-03-01

    The application of traditional Chinese medicine (TCM) and their preparations have a long history. With the deepening of the research, the market demand is increasing. However, wild resources are so limited that it can not meet the needs of the market. The development of wild and cultivated samples and research on accumulation dynamics of chemical component are of great significance. In order to compare composition difference of different parts (root, stem, and leaf) of wild and cultivated G. rigescens, Fourier infrared spectroscopy (FTIR) and second derivative spectra were used to analyze and evaluate. The second derivative spectra of 60 samples and the rate of affinity (the match values) were measured automatically using the appropriate software (Omnic 8.0). The results showed that the various parts of wild and cultivated G. rigescens. were high similar the peaks at 1732, 1 643, 1 613, 1 510, 1 417, 1 366, 1 322, 1 070 cm(-1) were the characteristic peak of esters, terpenoids and saccharides, respectively. Moreover, the shape and peak intensity were more distinct in the second derivative spectrum of samples. In the second derivative spectrum range of 1 800-600 cm(-1), the fingerprint characteristic peak of samples and gentiopicroside standards were 1 679, 1 613, 1 466, 1 272, 1 204, 1 103, 1 074, 985, 935 cm(-1). The characteristic peak intensity of gentiopicroside of roots of wild and cultivated samples at 1 613 cm(-1) (C-C) was higher than stems and leaves which indicated the higher content of gentiopicroside in root than in stem and leaves. Stems of wild samples at 1 521, 1 462 and 1 452 cm(-1) are the skeletal vibration peak of benzene ring of lignin, and the stem of cultivated sample have stronger peak than other samples which showed that rich lignin in stems. The iInfrared spectrum of samples were similar with the average spectral of root of wild samples, and significant difference was found for the correlation between second derivative spectrum of samples

  20. Fourier transform infrared spectroscopy of azide and cyanate ion pairs in AOT reverse micelles

    NASA Astrophysics Data System (ADS)

    Owrutsky, Jeffrey C.; Pomfret, Michael B.; Barton, David J.; Kidwell, David A.

    2008-07-01

    Evidence for ion pair formation in aqueous bis(2-ethylhexyl) sulfosuccinate (AOT) reverse micelles (RMs) was obtained from infrared spectra of azide and cyanate with Li+, Na+, K+, and NH4+ counterions. The anions' antisymmetric stretching bands near 2000 cm-1 are shifted to higher frequency (blueshifted) in LiAOT and to a lesser extent in NaAOT, but they are very similar to those in bulk water with K+ and NH4+ as the counterions. The shifts are largest for low values of wo=[water]/[AOT] and approach the bulk value with increasing wo. The blueshifts are attributed to ion pairing between the anions and the counterions. This interpretation is reinforced by the similar trend (Li+>Na+>K+) for producing contact ion pairs with the metal cations in bulk dimethyl sulfoxide (DMSO) solutions. We find no evidence of ion pairs being formed in NH4AOT RMs, whereas ammonium does form ion pairs with azide and cyanate in bulk DMSO. Studies are also reported for the anions in formamide-containing AOT RMs, in which blueshifts and ion pair formation are observed more than in the aqueous RMs. Ion pairs are preferentially formed in confined RM systems, consistent with the well established ideas that RMs exhibit reduced polarity and a disrupted hydrogen bonding network compared to bulk water and that ion-specific effects are involved in mediating the structure of species at interfaces.

  1. Application of Fourier transform infrared ellipsometry to assess the concentration of biological molecules.

    PubMed

    Garcia-Caurel, Enric; Drévillon, Bernard; De Martino, Antonello; Schwartz, Laurent

    2002-12-01

    Spectroscopic ellipsometry is a noninvasive optical characterization technique mainly used in the semiconductor field to characterize bare substrates and thin films. In particular, it allows the gathering of information concerning the physical structure of the sample, such as roughness and film thickness, as well as its optical response. In the mid-infrared (IR) range each molecule exhibits a characteristic absorption fingerprint, which makes this technique chemically selective. Phase-modulated IR ellipsometry does not require a baseline correction procedure or suppression of atmospheric CO2 and water-vapor absorption bands, thus greatly reducing the subjectivity in data analysis. We have found that ellipsometric measurements of thin films, such as the solid residuals left on a plane surface after evaporation of a liquid drop containing a given compound in solution, are particularly favorable for dosing purposes because the intensity of IR absorptions shows a linear behavior along a wide range of solution concentrations of the given compound. Our aim is to illustrate with a concrete example and to justify theoretically the linearity experimentally found between radiation absorption and molecule concentration. For the example, we prepared aqueous solutions of glycogen, a molecule of huge biological importance currently tested in biochemical analyses, at concentrations ranging from 1 mg/l to 1 g/l which correspond to those found in physiological conditions. The results of this example are promising for the application of ellipsometry for dosing purposes in biochemistry and biomedicine. PMID:12477127

  2. Study of Kerogen Maturity using Transmission Fourier Transform Infrared Spectroscopy (FTIR)

    NASA Astrophysics Data System (ADS)

    Dang, S. T.

    2014-12-01

    Maturity of kerogen in shale governs the productivity and generation hydrocarbon type. There are generally two accepted methods to measure kerogen maturity; one is the measurement of vitrinite reflectance, %Ro, and another is the measurement of Tmax through pyrolysis. However, each of these techniques has its own limits; vitrinite reflectance measurement cannot be applied to marine shale and pre-Silurian shales, which lack plant materials. Furthermore, %Ro, requires the isolation and identification of vitrinite macerals and statistical measurements of at least 50 macerals. Tmax measurement is questionable for mature and post-mature samples. In addition, there are questions involving the effects of solvents on Tmax determinations. Fourier Transmission Infrared Spectroscopy, FTIR, can be applied for both qualitative and quantitative assessment on organics maturity in shale. The technique does not require separating organic matter or identifying macerals. A CH2/CH3 index, RCH, calculated from FTIR spectra is more objective than other measurements. The index increases with maturity (both natural maturation and synthetic maturation through hydrous and dry pyrolysis). The new maturity index RCH can be calibrated to vitrinite reflectance which allows the definition of the following values for levels of maturity: 1) immature—RCH > 1.6±0.2; 2) oil window-- 1.6±0.2 < RCH > 1.3±0.3; 3) wet gas window--1.3±0.3 < RCH> 1.13±0.05; and 4) dry gas window RCH < 1.13±0.05.

  3. TRANSFORMER

    DOEpatents

    Baker, W.R.

    1959-08-25

    Transformers of a type adapted for use with extreme high power vacuum tubes where current requirements may be of the order of 2,000 to 200,000 amperes are described. The transformer casing has the form of a re-entrant section being extended through an opening in one end of the cylinder to form a coaxial terminal arrangement. A toroidal multi-turn primary winding is disposed within the casing in coaxial relationship therein. In a second embodiment, means are provided for forming the casing as a multi-turn secondary. The transformer is characterized by minimized resistance heating, minimized external magnetic flux, and an economical construction.

  4. Fourier Transform Infrared Spectroscopy of Low-k Dielectric Material on Patterned Wafers

    NASA Astrophysics Data System (ADS)

    Lam, Jeffrey Chorkeung; Tan, Hao; Huang, Maggie Yamin; Zhang, Fan; Sun, Handong; Shen, Zexiang; Mai, Zhihong

    2012-11-01

    With many of research on Fourier transform IR (FTIR) on low-k materials, our experiments extended the FTIR spectroscopy application to characterization and analysis of the low-k dielectric thin film properties on patterned wafers. FTIR spectra on low-k materials were successfully captured under three sampling modes: reflection, attenuated total reflectance (ATR), and mapping mode. ATR mode is more suitable for CHx band than reflection mode due to its higher sensitivity in this range. FTIR spectroscopy signal analysis on mixed structures (metal and low-k dielectric material) on patterned wafers was also investigated with mapping mode. Based on our investigation, FTIR can be used for low-k material studies on patterned wafer.

  5. Freeform lens collimating spectrum-folded Hadamard transform near-infrared spectrometer

    NASA Astrophysics Data System (ADS)

    Wang, Xiaoduo; Liu, Hua; Juschkin, Larissa; Li, Yunpeng; Xu, Jialin; Quan, Xiangqian; Lu, Zhenwu

    2016-12-01

    A novel Hadamard transform spectrometer collimated by a freeform lens has been designed, which doubles the working spectral range while the spectral resolution is maintained. The freeform lens is designed to redistribute the broadband spectra of the source from 800 nm to 2400 nm into two collimated beams with different wavelengths and different tilting angles, to achieve the folding of spectra on the digital micro-mirror devices (DMD). It is constructed by solving two partial differential equations. The grating diffraction efficiency of the two split beams are more uniform and higher compared with the traditional method. The simulation results show that the bandwidth of the spectrometer is doubled and the spectral resolution is better than 10 nm. The optical system becomes more compact, and the energy efficiency is improved by 11.98% by folding the spectra with one freeform lens and one grating.

  6. COMPARISON OF AN INNOVATIVE NONLINEAR ALGORITHM TO CLASSICAL LEAST SQUARES FOR ANALYZING OPEN-PATH FOURIER TRANSFORM INFRARED SPECTRA COLLECTED AT A CONCENTRATED SWINE PRODUCTION FACILITY

    EPA Science Inventory

    Open-path Fourier transform infrared (OP/FTIR) spectrometry was used to measure the concentrations of ammonia, methane, and other atmospheric gases at an integrated swine production facility. The concentration-pathlength products of the target gases at this site often exceeded th...

  7. APPLICATION OF STANDARDIZED QUALITY CONTROL PROCEDURES TO OPEN-PATH FOURIER TRANSFORM INFRARED DATA COLLECTED AT A CONCENTRATED SWINE PRODUCTION FACILITY

    EPA Science Inventory

    Open-path Fourier transform infrared (OP/FT-IR) spectrometry was used to measure the concentrations of ammonia, methane, and other atmospheric eases at a concentrated swine production facility. A total of 2200 OP/FT-IR spectra were acquired along nine different monitoring paths d...

  8. Evaluation of the Fourier transform infrared (FTIR) spectrophotometer for analysis of trichloroethylene (TCE) in the presence of freon-113 in carbon disulfide eluates of charcoal air sampling tubes

    SciTech Connect

    Xiao, H.K.; Levine, S.P.; Kinnes, G.; Almaguer, D. )

    1990-07-01

    Results obtained using Fourier transform infrared spectrophotometry (FTIR) for the analysis of samples of carbon disulfide (CS2) eluates containing trichloroethylene (TCE) and freon from charcoal air sampling tubes were evaluated by comparison with results obtained when using gas chromatography (GC). The FTIR yielded accurate results without regard to the presence of freon.

  9. Rapid identification and classification of Listeria spp. and serotype assignment of Listeria monocytogenes using fourier transform-infrared spectroscopy and artificial neural network analysis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The use of Fourier Transform-Infrared Spectroscopy (FT-IR) in conjunction with Artificial Neural Network software, NeuroDeveloper™ was examined for the rapid identification and classification of Listeria species and serotyping of Listeria monocytogenes. A spectral library was created for 245 strains...

  10. To See the World in a Grain of Sand: Recognizing the Origin of Sand Specimens by Diffuse Reflectance Infrared Fourier Transform Spectroscopy and Multivariate Exploratory Data Analysis

    ERIC Educational Resources Information Center

    Pezzolo, Alessandra De Lorenzi

    2011-01-01

    The diffuse reflectance infrared Fourier transform (DRIFT) spectra of sand samples exhibit features reflecting their composition. Basic multivariate analysis (MVA) can be used to effectively sort subsets of homogeneous specimens collected from nearby locations, as well as pointing out similarities in composition among sands of different origins.…

  11. Classification and structural analysis of live and dead salmonella cells using fourier transform infrared (FT-IR) spectroscopy and principle component analysis (PCA)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fourier Transform Infrared Spectroscopy (FT-IR) was used to detect Salmonella typhimurium and Salmonella enteritidis foodborne bacteria and distinguish between live and dead cells of both serotypes. Bacteria were loaded individually on the ZnSe Attenuated Total Reflection (ATR) crystal surface and s...

  12. Differentiation of Asian ginseng, American ginseng and Notoginseng by Fourier transform infrared spectroscopy combined with two-dimensional correlation infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Lu, Guang-hua; Zhou, Qun; Sun, Su-qin; Leung, Kelvin Sze-yin; Zhang, Hao; Zhao, Zhong-zhen

    2008-07-01

    The herbal materials of Asian ginseng (the root of Panax ginseng), American ginseng (the root of Panax quinquefolius) and Notoginseng (the root of Panax notoginseng) were differentiated by conventional Fourier transform infrared spectroscopy (1D-FTIR) and two-dimensional (2D) correlation FTIR applying a thermal perturbation. Altogether 30 samples were collected and analyzed. Their entire 1D-FTIR spectra in the range of 4000-400 cm -1 and 2D-FTIR spectra in the region of 850-1530 cm -1 were generally similar based on the peaks position and intensities. This indicated the chemical constituents in these species of herbs were not distinctively different. However, variation in peak intensity were observed at about 1640 cm -1, 1416 cm -1, 1372 cm -1 and 1048 cm -1 in the 1D-FTIR spectra among these species for their ease differentiation. Clustering analysis of 1D-FTIR showed that these species located in different clusters. Much difference in their second derivative FTIR pattern among the three species also provided information for easy differentiation. These species of herbs were further identified based on the positions and intensities of relatively strong auto-peaks, positive or negative cross-peaks in their 2D-FTIR spectra. The findings provide a rapid and new operational procedure for the differentiation of these notable herbs. The visual and colorful 2D-FTIR spectra can provide dynamic structural information of chemical components in analyte and demonstrated as a powerful and useful approach for herbs identification.

  13. OSCILLATOR: A system for analysis of diurnal leaf growth using infrared photography combined with wavelet transformation

    PubMed Central

    2012-01-01

    Background Quantification of leaf movement is an important tool for characterising the effects of environmental signals and the circadian clock on plant development. Analysis of leaf movement is currently restricted by the attachment of sensors to the plant or dependent upon visible light for time-lapse photography. The study of leaf growth movement rhythms in mature plants under biological relevant conditions, e.g. diurnal light and dark conditions, is therefore problematic. Results Here we present OSCILLATOR, an affordable system for the analysis of rhythmic leaf growth movement in mature plants. The system contains three modules: (1) Infrared time-lapse imaging of growing mature plants (2) measurement of projected distances between leaf tip and plant apex (leaf tip tracking growth-curves) and (3) extraction of phase, period and amplitude of leaf growth oscillations using wavelet analysis. A proof-of-principle is provided by characterising parameters of rhythmic leaf growth movement of different Arabidopsis thaliana accessions as well as of Petunia hybrida and Solanum lycopersicum plants under diurnal conditions. The amplitude of leaf oscillations correlated to published data on leaf angles, while amplitude and leaf length did not correlate, suggesting a distinct leaf growth profile for each accession. Arabidopsis mutant accession Landsberg erecta displayed a late phase (timing of peak oscillation) compared to other accessions and this trait appears unrelated to the ERECTA locus. Conclusions OSCILLATOR is a low cost and easy to implement system that can accurately and reproducibly quantify rhythmic growth of mature plants for different species under diurnal light/dark cycling. PMID:22867627

  14. Fourier transform emission spectroscopy of the near infrared transitions of CeS

    NASA Astrophysics Data System (ADS)

    Ram, R. S.; Bernath, P. F.

    2014-05-01

    The emission spectra of CeS have been investigated at high resolution with a Fourier transform spectrometer. Several bands observed in the 4000-9000 cm-1 region have been classified into nine transitions having five different lower states, X1(3), X2(⩾ 2), X3(⩾ 2), X4(⩾ 3) and X5(0) based on Ω doubling and relative branch intensities. Out of these, the [7.54] (4) → X1(3) transition consisting of 0-1, 1-2, 0-0, 1-1, 1-0 and 2-1 bands is strongest in intensity. A rotational analysis of these bands provides equilibrium spectroscopic constants: ωe = 461.3947(14) cm-1, ωexe = 1.00095(65) cm-1, Be = 0.118782207(15) cm-1, αe = 0.000341453(14) cm-1 and re = 2.33522875(15) Å for the lower X1(Ω = 3) state. The [8.78] (⩾3) → X2(⩾2) transition, for which 0-0 and 0-1 bands were rotationally analyzed, provides ΔG½ = 458.87411(88) cm-1, Be = 0.1187649(31) cm-1, αe = 0.0003401(37) cm-1 and re = 2.335399(31) Å for the X2(Ω ⩾ 2) lower state.

  15. A new direct Fourier transform infrared analysis of free fatty acids in edible oils using spectral reconstitution.

    PubMed

    Yu, Xiuzhu; van de Voort, F R; Sedman, Jacqueline; Gao, Jin-ming

    2011-07-01

    A new transmission-based Fourier transform infrared (FTIR) spectroscopic method for the direct determination of free fatty acids (FFA) in edible oils has been developed using the developed spectral reconstitution (SR) technique. Conventional neat-oil and SR calibrations were devised by spiking hexanoic acid into FFA-free canola oil and measuring the response to added FFA at 1,712 cm(-1) referenced to a baseline at 1,600 cm(-1)(1,712 cm(-1)/1,600 cm(-1)). To compensate for the known oil dependency of such calibration equations resulting from variation of the triacylglycerol ester (C═O) absorption with differences in oil saponification number (SN), a correction equation was devised by recording the spectra of blends of two FFA-free oils (canola and coconut) differing substantially in SN and correlating the intensity of the ester (C═O) absorption at the FFA measurement location with the intensity of the first overtone of this vibration, measured at 3,471 cm(-1)/3,427 cm(-1). Further examination of the spectra of the oil blends by generalized 2D correlation spectroscopy revealed an additional strong correlation with an absorption in the near-infrared (NIR) combination band region, which led to the development of a second correction equation based on the absorbance at 4,258 cm(-1)/4,235 cm(-1). The NIR-based correction equation yielded superior results and was shown to completely eliminate biases due to variations in oil SN, thereby making a single FFA calibration generally applicable to oils, regardless of SN. FTIR methodology incorporating this correction equation and employing the SR technique has been automated.

  16. A new direct Fourier transform infrared analysis of free fatty acids in edible oils using spectral reconstitution.

    PubMed

    Yu, Xiuzhu; van de Voort, F R; Sedman, Jacqueline; Gao, Jin-ming

    2011-07-01

    A new transmission-based Fourier transform infrared (FTIR) spectroscopic method for the direct determination of free fatty acids (FFA) in edible oils has been developed using the developed spectral reconstitution (SR) technique. Conventional neat-oil and SR calibrations were devised by spiking hexanoic acid into FFA-free canola oil and measuring the response to added FFA at 1,712 cm(-1) referenced to a baseline at 1,600 cm(-1)(1,712 cm(-1)/1,600 cm(-1)). To compensate for the known oil dependency of such calibration equations resulting from variation of the triacylglycerol ester (C═O) absorption with differences in oil saponification number (SN), a correction equation was devised by recording the spectra of blends of two FFA-free oils (canola and coconut) differing substantially in SN and correlating the intensity of the ester (C═O) absorption at the FFA measurement location with the intensity of the first overtone of this vibration, measured at 3,471 cm(-1)/3,427 cm(-1). Further examination of the spectra of the oil blends by generalized 2D correlation spectroscopy revealed an additional strong correlation with an absorption in the near-infrared (NIR) combination band region, which led to the development of a second correction equation based on the absorbance at 4,258 cm(-1)/4,235 cm(-1). The NIR-based correction equation yielded superior results and was shown to completely eliminate biases due to variations in oil SN, thereby making a single FFA calibration generally applicable to oils, regardless of SN. FTIR methodology incorporating this correction equation and employing the SR technique has been automated. PMID:21556753

  17. Infrared study and phase transformation of the new lithium-diphenyl carbazide complex (LiDPC)

    NASA Astrophysics Data System (ADS)

    El-Kabbany, F.; Taha, S.; Hafez, M.; Abdel Aziz, N. R.

    2015-07-01

    A complete IR investigation (400-4000 cm-1) of orthorhombic, amorphous DPC and crystalline LiDPC (at room temperature and 80 °C) is performed and new results are reported. Introducing lithium ions into diphenyl carbazide C13H14N4O forms a completely new complex associated with new properties. The IR spectroscopic analysis includes measurements and interpretation of the IR spectral band shape, intensities, and frequencies of the internal modes of vibrations. The principle modes of vibrations of amorphous DPC found to be 3445 cm-1, 3292 cm-1, 3052 cm-1, 1670 cm-1, 1602 cm-1, 1495 cm-1, 1305 cm-1, 1254 cm-1, 974 cm-1, and 577 cm-1 correspond to normal vibrations of Nsbnd H, Csbnd H, Nsbnd N, Cdbnd O and monosubstituted benzene. A marked change could be recorded for these modes of vibrations in the presence of Li+ ions. The results strongly confirm the formation of a metal-organic complex. Anomalous spectroscopic changes could be recorded in LiDPC spectra. A proposed Li+ position in LiDPC complex is proposed. X-ray diffraction analysis is used to find out the crystal structure and parameters of LiDPC complex. The results obtained show triclinic crystal structure with a = 5.6929 Å, b = 7.6378 Å, c = 17.8739 Å, α = 119.176°, β = 63.322°, γ = 85.378°. The results reveal the presence of an order-disorder phase transition in LiDPC complex at 60 °C. The transformation process is monitored by clear variations in the spectral shape, band intensities and new eight different modes appeared in the high temperature disordered phase. An energy model is suggested for the interpretation of such phase transition process.

  18. HIGH-RESOLUTION FOURIER TRANSFORM SPECTROSCOPY OF LANTHANUM IN Ar DISCHARGE IN THE NEAR-INFRARED

    SciTech Connect

    Güzelçimen, F.; Başar, Gö.; Tamanis, M.; Kruzins, A.; Ferber, R.; Windholz, L.; Kröger, S. E-mail: sophie.kroeger@htw-berlin.de

    2013-10-01

    A high-resolution spectrum of lanthanum has been recorded by a Fourier Transform spectrometer in the wavelength range from 833 nm to 1666 nm (6000 cm{sup –1} to 12,000 cm{sup –1}) using as light source a hollow cathode lamp operated with argon as the discharge carrier gas. In total, 2386 spectral lines were detected in this region, of which 555 lines could be classified as La I transitions and 10 lines as La II transitions. All La II transitions and 534 of these La I transitions were classified for the first time, and 6 of the La II transitions and 433 of the classified La I transitions appear to be new lines, which could not be found in the literature. The corresponding energy level data of classified lines are given. Additionally, 430 lines are assigned as Ar I lines and 394 as Ar II lines, of which 179 and 77, respectively, were classified for the first time. All 77 classified Ar II transitions as well as 159 of the classified Ar I transitions are new lines. Furthermore, the wavenumbers of 997 unclassified spectral lines were determined, 235 of which could be assigned as La lines, because of their hyperfine pattern. The remaining 762 lines may be either unclassified Ar lines or unresolved and unclassified La lines with only one symmetrical peak with an FWHM in the same order of magnitude as the Ar lines. The accuracy of the wavenumber for the classified lines with signal-to-noise-ratio higher than four is better than 0.006 cm{sup –1} which corresponds to an accuracy of 0.0004 nm at 830 nm and 0.0017 nm at 1660 nm, respectively.

  19. Attenuated Total Reflection Mid-Infrared (ATR-MIR) Spectroscopy and Chemometrics for the Identification and Classification of Commercial Tannins.

    PubMed

    Ricci, Arianna; Parpinello, Giuseppina P; Olejar, Kenneth J; Kilmartin, Paul A; Versari, Andrea

    2015-11-01

    Attenuated total reflection Fourier transform infrared (FT-IR) spectroscopy was used to characterize 40 commercial tannins, including condensed and hydrolyzable chemical classes, provided as powder extracts from suppliers. Spectral data were processed to detect typical molecular vibrations of tannins bearing different chemical groups and of varying botanical origin (univariate qualitative analysis). The mid-infrared region between 4000 and 520 cm(-1) was analyzed, with a particular emphasis on the vibrational modes in the fingerprint region (1800-520 cm(-1)), which provide detailed information about skeletal structures and specific substituents. The region 1800-1500 cm(-1) contained signals due to hydrolyzable structures, while bands due to condensed tannins appeared at 1300-900 cm(-1) and exhibited specific hydroxylation patterns useful to elucidate the structure of the flavonoid monomeric units. The spectra were investigated further using principal component analysis for discriminative purposes, to enhance the ability of infrared spectroscopy in the classification and quality control of commercial dried extracts and to enhance their industrial exploitation.

  20. Characterizing Aeroallergens by Infrared Spectroscopy of Fungal Spores and Pollen

    PubMed Central

    Zimmermann, Boris; Tkalčec, Zdenko; Mešić, Armin; Kohler, Achim

    2015-01-01

    Background Fungal spores and plant pollen cause respiratory diseases in susceptible individuals, such as asthma, allergic rhinitis and hypersensitivity pneumonitis. Aeroallergen monitoring networks are an important part of treatment strategies, but unfortunately traditional analysis is time consuming and expensive. We have explored the use of infrared spectroscopy of pollen and spores for an inexpensive and rapid characterization of aeroallergens. Methodology The study is based on measurement of spore and pollen samples by single reflectance attenuated total reflectance Fourier transform infrared spectroscopy (SR-ATR FTIR). The experimental set includes 71 spore (Basidiomycota) and 121 pollen (Pinales, Fagales and Poales) samples. Along with fresh basidiospores, the study has been conducted on the archived samples collected within the last 50 years. Results The spectroscopic-based methodology enables clear spectral differentiation between pollen and spores, as well as the separation of confamiliar and congeneric species. In addition, the analysis of the scattering signals inherent in the infrared spectra indicates that the FTIR methodology offers indirect estimation of morphology of pollen and spores. The analysis of fresh and archived spores shows that chemical composition of spores is well preserved even after decades of storage, including the characteristic taxonomy-related signals. Therefore, biochemical analysis of fungal spores by FTIR could provide economical, reliable and timely methodologies for improving fungal taxonomy, as well as for fungal identification and monitoring. This proof of principle study shows the potential for using FTIR as a rapid tool in aeroallergen studies. In addition, the presented method is ready to be immediately implemented in biological and ecological studies for direct measurement of pollen and spores from flowers and sporocarps. PMID:25867755