scholarly journals Infrared spectra of some fructans

2002 ◽  
Vol 16 (3-4) ◽  
pp. 289-296 ◽  
Author(s):  
M. Grube ◽  
M. Bekers ◽  
D. Upite ◽  
E. Kaminska
Keyword(s):  
Molecular Weight ◽  
Ir Spectra ◽  
Infrared Spectra ◽  
Special Interest ◽  
Zymomonas Mobilis ◽  
Food Industry ◽  
Broad Band ◽  
Linear Chains ◽  
Ft Ir ◽  
Main Component

The FT–IR spectra of fructan – inulin (RAFTILINE), widely applied in the food industry and crystalline fructose as the main component of fructans, were studied. Special interest was to study the spectra of the levan precipitate and fructan syrup – produced byZymomonas mobilisduring the fermentation on sucrose–based medium.It was shown that levan precipitate and fructose syrup does not contain lipids and nucleic acids. Levan precipitate consists of ∼93% of fructose and admixture of glucose, mannan and enzyme – levansucrase. Fructan polymer inulin consists principally of linear chains of fructosyl units linked by aβ(2–1) bonds ended by a glycosyl unit. The links between the molecules are of a very special type: theβ(2–1) form (2) [8]. The bacterial fructans of the levan type are high molecular weight polymers, i.e., they are composed ofβ–(2,6)–ructosyl–fructose linked molecules and side chains [17]. The FT–IR spectra of levan, apart from inulin’s, in the carbohydrate region 900–1200 cm–1, shows overlapping broad band with maximum at ∼1030 cm–1and stronger absorption at ∼940 cm–1. The differences in both spectra could be caused by different structure and glucose, sucrose and mannan influence.

scholarly journals Infrared Spectra: Useful Technique to Identify the Conductivity Level of Emeraldine form of Polyaniline and Indication of Conductivity Measurement either Two or Four Probe Technique

2018 ◽  
Vol 15 (3) ◽  
pp. 209-217 ◽  
Author(s):  
Palaniappan Srinivasan ◽  
Ramesh Gottam
Keyword(s):  
Fourier Transform ◽  
Ir Spectra ◽  
Infrared Spectra ◽  
Ir Spectrum ◽  
Conductivity Measurement ◽  
Ammonium Persulfate ◽  
Emeraldine Salt ◽  
Probe Technique ◽  
Water Solvent ◽  
Ft Ir

A new insight was watched the connection between’s the conductivity and Fourier Transform Infrared (FT-IR) spectra of the emeraldine type of polyaniline (PANI) structures. The conductivity of polyaniline emeraldine salt (PANI-ES) can be varied from 101 to 10-12 S cm-1. FT-IR spectrum is a tool to determine the conductivity level and also conductivity measuring methods of PANI system, i.e., either two probe or four probe techniques. This information is very useful for the researcher and industrialists working on emeraldine form of PANI systems to identify the conductivity level and method of measurements from FT-IR spectra. This data was seen from the infrared spectra of different PANI salts obtained by the oxidation of aniline in water/solvent medium by ammonium persulfate (APS) without utilizing any acids. PANI-ES samples having reasonably good conductivity (> 0.3 S cm-1) showed mostly nanowires or nanorods morphology, whereas, lower conductivity (< 0.3 S cm-1) samples showed mostlyagglomerated spheres or particles morphology. In these investigations, however, no report was made of the use of infrared technic to determine the conductivity of PANI system.

Application of Fourier Self-Deconvolution to the FT-IR Spectra of Polydimethylsiloxane Oligomers for Determining Chain Length

1986 ◽  
Vol 40 (7) ◽  
pp. 1009-1011 ◽  
Author(s):  
Elmer D. Lipp
Keyword(s):  
Ir Spectra ◽  
Chain Length ◽  
Infrared Spectra ◽  
Effective Means ◽  
Resolution Enhancement ◽  
Relative Size ◽  
Enhancement Technique ◽  
Molecular Weights ◽  
Ft Ir ◽  
Resolution Enhancement Technique

The resolution enhancement technique of Fourier self-deconvolution is applied to the FT-IR spectra of linear polydimethylsiloxane oligomers. A series of pure oligomers of known chain length is analyzed in regions characteristic of silicon-methyl modes in order to separate dimethyl from trimethyl contributions. Once separated, the relative size of the deconvoluted peaks can be quantitatively related to the chain length of the oligomers. This proves to be an effective means of obtaining chain length information from the infrared spectra and is applicable to oligomers having molecular weights up to 15,000.

Crystal structures and FT-IR spectra of three N,N-dicyclohexylmethylammonium halides C13H26N+X− (X = Cl, Br, I)

2019 ◽  
Vol 74 (1) ◽  
pp. 119-124
Author(s):  
Sebastian Fäth ◽  
Max Vilsmeier ◽  
Arno Pfitzner
Keyword(s):  
Hydrogen Bond ◽  
Fourier Transform ◽  
Ir Spectra ◽  
Crystal Structures ◽  
Infrared Spectra ◽  
Halide Ions ◽  
Orthorhombic Space Group ◽  
Hydrogen Bond Acceptor ◽  
Space Group ◽  
Ft Ir

AbstractThe title compounds C13H26N+Cl− (N,N-dicyclohexylmethylammonium chloride), C13H26N+Br− (N,N- dicyclohexylmethylammonium bromide) and C13H26N+I− (N,N-dicyclohexylmethylammonium iodide) are isostructural and crystallize in the orthorhombic space group Pna21 with the lattice parameters a=7.580(1), b=19.072(1), c=9.165(1) Å, V=1324.9(1) Å3 for X=Cl, a=7.765(1), b=19.054(1), c=9.270(1) Å, V=1371.5(1) Å3 for X=Br, and a=8.102(1), b=19.084(1), c=9.535(1) Å, V=1474.2(1) Å3 for X=I with Z=4 for each compound. Their cyclohexyl groups are aligned along [010] while their halide ions are coordinated along [100] by a strong linear N–H···X (X=Cl, Br, I) hydrogen bond. Fourier-transform infrared spectra show a decreasing hydrogen bond acceptor strength from the chloride to the iodide.

Examinations of the Matrix Isolation Fourier Transform Infrared Spectra of Organic Compounds: Part XII

1989 ◽  
Vol 43 (2) ◽  
pp. 298-304 ◽  
Author(s):  
W. M. Coleman ◽  
Bert M. Gordon ◽  
Brian M. Lawrence
Keyword(s):  
Fourier Transform ◽  
Ir Spectra ◽  
Infrared Spectra ◽  
Matrix Isolation ◽  
Fourier Transform Infrared ◽  
Fourier Transform Infrared Spectra ◽  
The Matrix ◽  
Ft Ir ◽  
Nanogram Level ◽  
C Nmr

Matrix isolation Fourier transform infrared spectra (MI/FT-IR), mass spectra (MS), carbon-13 Nuclear Magnetic Resonance (13C-NMR) spectra, condensed-phase infrared spectra, and vapor-phase infrared (IR) spectra are presented for a series of terpene compounds. Subtle differences in positional and configurational isomers commonly found with terpenes could be easily detected by the MI/FT-IR spectra. The results are comparable in some aspects to those obtainable from 13C-NMR and thin-film IR; however, most importantly, they are acquired at the low nanogram level for MI/FT-IR, as compared to the milligram level for the other techniques. These results represent an advance in the technology available for the analysis of complex mixtures such as essential oils containing terpene-like molecules.

scholarly journals Evaluation of the biomedical properties of hydroxyapatite obtained from bone waste

2009 ◽  
Vol 11 (1) ◽  
pp. 37-43 ◽  
Author(s):  
Agnieszka Sobczak ◽  
Anna Kida ◽  
Zygmunt Kowalski ◽  
Zbigniew Wzorek
Keyword(s):  
Infrared Spectroscopy ◽  
Thermal Treatment ◽  
Ir Spectra ◽  
Calcium Content ◽  
Organic Substances ◽  
X Ray Diffraction ◽  
X Ray ◽  
Fourier Transformed Infrared Spectroscopy ◽  
Ft Ir ◽  
Main Component

Evaluation of the biomedical properties of hydroxyapatite obtained from bone waste The method of obtaining hydroxyapatite by thermal treatment of deproteinised and defatted bone pulp called bone sludge was presented. The products of the calcining process were characterized with X-ray diffraction (XRD) and Fourier transformed infrared spectroscopy (FT-IR). The calcium content was determined with titration, whereas the contents of total phosphorus - with a spectrophotomertric method. X-ray investigations confirmed that hydroxyapatite was the main component of the calcining products in the calcining process. The FT-IR spectra confirmed that all organic substances were removed during the calcining process. On the basis of the research into physiological liquids the propensity to resorption of hydroxyapatite bioceramic was evaluated.

Light- or Dark-Colored, L-DOPA-Based Melanins

2018 ◽  
Author(s):  
Koen Vercruysse ◽  
Margaret M. Whalen
Keyword(s):  
Human Physiology ◽  
Ir Spectra ◽  
Immune Cells ◽  
Chemical Properties ◽  
Chemical Signature ◽  
Ft Ir

<p>This report is a continuation of previous research on the H<sub>2</sub>O<sub>2</sub>-mediated synthesis of melanin-like pigments. We synthesized and characterized L-DOPA-based pigments using air- or H<sub>2</sub>O<sub>2</sub>-mediated<sub> </sub>oxidation. We compared their physic-chemical properties and evaluated their capacity to affect the interleukin release from immune cells. The use of higher concentrations of H<sub>2</sub>O<sub>2</sub> resulted in melanin-like materials with a distinct chemical signature in their FT-IR spectra and a lighter color. All pigments enhanced the interleukin release from immune cells. The possibility that lighter-colored melanins can be generated is discussed in the context of the importance of melanin-based pigmentation in human physiology.</p>

scholarly journals Spectroscopy as a useful tool for the identification of changes with time in post-mortem vitreous humor for forensic toxicology purposes

2021 ◽  
Author(s):  
Anna Wójtowicz ◽  
Agata Mitura ◽  
Renata Wietecha-Posłuszny ◽  
Rafał Kurczab ◽  
Marcin Zawadzki
Keyword(s):  
Ir Spectra ◽  
Forensic Toxicology ◽  
Principal Component ◽  
Hierarchical Cluster ◽  
Vitreous Humor ◽  
Attenuated Total Reflection ◽  
Glass Slides ◽  
Added Benefit ◽  
Ft Ir ◽  
Non Destructive

AbstractVitreous humor (VH) is an alternative biological matrix with a great advantage of longer availability for analysis due to the lack of many enzymes. The use of VH in forensic toxicology may have an added benefit, however, this application requires rapid, simple, non-destructive, and relatively portable analytical analysis methods. These requirements may be met by Fourier transform infrared spectroscopy technique (FT-IR) equipped with attenuated total reflection accessory (ATR). FT-IR spectra of vitreous humor samples, deposited on glass slides, were collected and subsequent chemometric data analysis by means of Hierarchical Cluster Analysis and Principal Component Analysis was conducted. Differences between animal and human VH samples and human VH samples stored for diverse periods of time were detected. A kinetic study of changes in the VH composition up to 2 weeks showed the distinction of FT-IR spectra collected on the 1st and 14th day of storage. In addition, data obtained for the most recent human vitreous humor samples—collected 3 and 2 years before the study, presented successful discrimination of all time points studied. The method introduced was unable to detect mephedrone addition to VH in the concentration of 10 µg/cm3. Graphic abstract

Luminescent Properties of Zn2SiO4:Eu3+,Dy3+ Phosphors via Sol-Gel Process

2012 ◽  
Vol 217-219 ◽  
pp. 733-736
Author(s):  
Xiu Mei Han ◽  
Shu Ai Hao ◽  
Ying Ling Wang ◽  
Gui Fang Sun ◽  
Xi Wei Qi
Keyword(s):  
Thermal Analysis ◽  
Ir Spectra ◽  
Sol Gel ◽  
Luminescent Properties ◽  
Photoluminescence Spectra ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sol Gel Process ◽  
Ft Ir

Zn2SiO4:Eu3+, Dy3+ phosphors have been prepared through the sol-gel process. X-ray diffraction (XRD), thermogravimetric and ddifferential thermal analysis (TG-DTA), FT-IR spectra and photoluminescence spectra were used to characterize the resulting phosphors. The results of XRD indicated that the phosphors crystallized completely at 1000oC. In Zn2SiO4:Eu3+,Dy3+ phosphors, the Eu3+ and Dy3+ show their characteristic red(613nm, 5D0-7F2), blue (481nm, 4F9/2–6H15/2) and yellow (577nm, 4F9/2–6H13/2) emissions.

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