scholarly journals STUDY OF THE POSSIBILITY OF USING IR-SPECTROSCOPY FOR THE IDENTIFICATION OF A VARIETY OF SEA BUCKTHORN FRUIT (НIPPOPHAES RHAMNOIDES L.)

2019 ◽  
pp. 301-308
Author(s):  
Ольга (Ol'ga) Валерьевна (Valer'evna) Тринеева (Trineeva) ◽  
Маргарита (Margarita) Александровна (Aleksandrovna) Рудая (Rudaya) ◽  
Елена (Elena) Федоровна (Fedorovna) Сафонова (Safonova) ◽  
Алексей (Aleksey) Иванович (Ivanovich) Сливкин (Slivkin)
Keyword(s):  
Ir Spectroscopy ◽  
Hydrogen Bonds ◽  
Sea Buckthorn ◽  
Biologically Active ◽  
Absorption Bands ◽  
Specific Frequency ◽  
Ft Ir ◽  
Dry Fruit ◽  
Absorption Frequencies ◽  
Ft Ir Spectroscopy

The purpose of this study was to study the feasibility of using IR spectroscopy (IRS) to identify the fruit of sea buckthorn and buckthorn varieties. Fourier species of sea-buckthorn of buckthorn species studied were analyzed by FT-IR spectroscopy of disturbed total internal reflection (FTIR). IR spectra of sea buckthorn fruits was characterized by the presence of specific absorption bands: for grades «Gallery», «Вotanical», «Trofimovskaya» and «Krasnokarminovaya» in the range 3009-3006; 1456-1443 and 1379-1375 cm-1; for varieties «Rowan», «Botanical amateur» and «Student» in the range of 1338-1321 cm-1; for varieties «Rowan», «Botanical aromatic» and «Krasnokarminovaya» in the range of 1155-1146 cm-1; for varieties «Rowan» and «Krasnokarminovaya» at 914 cm-1; for varieties «Galerit», «Botanicheskaya» and «Krasnokarminovaya» in the range of 609-592 cm-1; for varieties «Trofimovskaya» and «Krasnokarminovaya» at 814-812 cm-1; for the variety «Rowan» at 424 cm-1 and for the variety «Trofimovskaya» at 771 cm-1. The highest intensity in absorption maxima is characteristic for infrared spectra of the fruits of the varieties «Rowan», «Botanical Amateur», «Botanical Aromatic» and «Student». Identified specific frequency in the spectrum can be regarded as characteristic for a particular grade and use them as markers in determining the authenticity and graded supplies dry fruit of sea buckthorn by IR spectroscopy. The formation of hydrogen bonds and their characteristics (size and energy) between molecules of biologically active substances (BAS) in the LRS studied are established. The revealed intermolecular hydrogen bonds belong to the type of strong bonds, since their energy exceeds 5 kcal/mol, and the length is about 2.7 Ǻ. Polyphenolic BAS in fruits, according to the IRS, form polyassociates with characteristic absorption frequencies at 3400-3200 cm-1.

Concurrent Determination of Optical Constants and the Kramers-Kronig Integration Constant (Anchor Point) Using Variable-Angle ATR/FT-IR Spectroscopy

1992 ◽  
Vol 46 (12) ◽  
pp. 1848-1858 ◽  
Author(s):  
Lane D. Tickanen ◽  
M. Isabel Tejedor-Tejedor ◽  
Marc A. Anderson
Keyword(s):  
Refractive Index ◽  
Ir Spectroscopy ◽  
Optical Constants ◽  
Attenuated Total Reflection ◽  
Anchor Point ◽  
Separate Experiment ◽  
Absorption Bands ◽  
Variable Angle ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

Attenuated total reflection Fourier transform infrared (ATR/FT-IR) spectroscopy has been used to determine optical constants in the infrared region of the spectrum for a variety of materials. Usually, the Kramers-Kronig transform is used to obtain optical constants from spectra, given that the baseline refractive index (anchor point) is known or can be determined. This determination often involves performing a separate experiment in which the refractive index of the sample is measured in a nonabsorbing region of the visible part of the spectrum, and the result extrapolated to the infrared. However, this is not feasible for opaque samples or for ones that contain domains large enough to scatter visible light. In this paper, we present a method for concurrently determining the anchor point and the optical constants using only variable-angle ATR/FT-IR spectroscopy and the subtractive form of the Kramers–Kronig transform. The method for determining the anchor point involves ratioing pATR (the negative log of the intensity of the ATR spectrum) values from weak absorption bands from spectra recorded at different angles of incidence. The anchor point can then be determined by computer. The only requirements are that the ATR system use unpolarized radiation and that the sample be thicker than the sampling depth of the IR radiation.

Determination of the Presence of Composite Ions in Catalysts and Composite Ionic Liquids-Catalyzed Isobutane Alkylation

2011 ◽  
Vol 287-290 ◽  
pp. 1666-1670 ◽  
Author(s):  
Ying Nan Cong ◽  
Ying Liu ◽  
Rui Sheng Hu
Keyword(s):  
Ionic Liquid ◽  
Ionic Liquids ◽  
Ir Spectroscopy ◽  
Catalytic Performance ◽  
Ir Absorption ◽  
Absorption Bands ◽  
Alkyl Groups ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

A novel and efficient method was established to investigate isobutane/2-butene alkylation. In this method FT-IR spectroscopy was used to determine the presence of the composite ion (AlCuCl5-) in the composite ionic liquid (CIL). The trimethylpentane selectivity of the composite ionic liquid for isobutane/2-butene alkylation was also estimated by monitoring the shift of IR absorption bands in the range 1636–1685 cm-1. A detailed study of the alkylation of isobutane /2-butene in CIL media has been conducted using 1-alkyl-3-methylimidazolium halide/X aluminum chloride-y cuprous (I) chloride ([CnMIM]Cl/xAlCl3-yCuCl) encompassing various alkyl groups (n=4:B, butyl-, n=6:H, hexyl-, and n=8: O, octyl-)respectively. The ionic liquids showed higher selectivities of C8 as well as the TMP/DMH ratios in alkylates. The better catalytic performance of CIL can be attributed to the presence of the composite ion in it, and the catalytic performance of the chloroaluminate ionic liquid can be indicated by the 1685 cm-1band of FT-IR spectroscopy.

scholarly journals Molecular spectroscopy analysis of the substitution of bone tissue by HAp/PLLA composite biomaterial

2004 ◽  
Vol 18 (4) ◽  
pp. 553-565 ◽  
Author(s):  
Nenad Ignjatovic ◽  
Dragan Uskokovic
Keyword(s):  
Electron Microscopy ◽  
Molecular Weight ◽  
Scanning Electron Microscopy ◽  
Ir Spectroscopy ◽  
Molecular Spectroscopy ◽  
Absorption Bands ◽  
Molecular Weights ◽  
Ft Ir ◽  
Scanning Electron ◽  
Ft Ir Spectroscopy

Due to its pronounced osteoinductive properties, calcium hydroxyapatite (HAp) has been widely used in medicine. Bioresorptive poly-L-lactide (PLLA) as a polymer biomaterial has been also used extensively in medicine for its non-toxicity and biocompatibility. To combine the advantages exhibited by each of these materials, a HAp/PLLA composite biomaterial has been synthesized and used for reconstruction and repair of bone defects. Hydroxyapatite/poly-L-lactide (HAp/PLLA) composite biomaterial with PLLA of 50,000 and 430,000 g/mole molecular weight was studiedin vivo. The biocomposite with PLLA of both molecular weights was implanted into mice, then removed from their organisms and analyzed by the Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM) and histopathologic analysis. Characteristic absorption bands, registered and defined by FT-IR spectroscopy, confirm the formation of new functional groups and compounds during the bone repair process using HAp/PLLA biocomposite with PLLA of 50,000 and 430,000 molecular weights. Analysis of the microstructures of the sample surfaces by scanning electron microscopy (SEM) before and after implantation revealed bioresorption of the PLLA polymer phase in the system with PLLA of lower molecular weight and generation of collagen fibers at the sites of implanted bioresorptive PLLA. As the studied synthetic materials behave as the natural bone, i.e., they are phagocytosed and resorpable, they can be considered as biocompatible.

scholarly journals Composite materials based on dental acrylic plastic and chitosan

2021 ◽  
Vol 8 (4) ◽  
pp. 20218413
Author(s):  
L. A. Yakovishin ◽  
E. V. Tkachenko
Keyword(s):  
Composite Materials ◽  
Ir Spectroscopy ◽  
Hydrogen Bonds ◽  
Polymer Composites ◽  
Hydrophobic Interactions ◽  
Mechanochemical Method ◽  
Intermolecular Hydrogen Bonds ◽  
Dental Acrylic ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

Chitosan and poly(methyl methacrylate) (PMMA) composites were synthesized by polymerization with heating and mechanochemical method. The obtained polymer composites were analyzed by the ATR FT-IR spectroscopy method. The presence of intermolecular hydrogen bonds and hydrophobic interactions in formation of PMMA and chitosan polymer composites was shown.

scholarly journals MOLECULAR COMPLEXES OF IVY TRITERPENE GLYCOSIDES WITH CHOLESTEROL

2018 ◽  
pp. 133-140 ◽  
Author(s):  
Леонид (Leonid) Александрович (Aleksandrovich) Яковишин (Yakovishin) ◽  
Владимир (Vladimir) Иванович (Ivanovich) Гришковец (Grishkovets)
Keyword(s):  
Ir Spectroscopy ◽  
Aqueous Ethanol ◽  
Molecular Complexes ◽  
Total Reflection ◽  
Attenuated Total Reflection ◽  
Triterpene Saponins ◽  
Absorption Bands ◽  
Ft Ir ◽  
Hederasaponin C ◽  
Ft Ir Spectroscopy

Molecular complexes of cholesterol with dominant triterpene saponins from members of the ivy genus Hedera L. (Araliaceae Juss.) – monodesmosidic glycoside α-hederin (hederagenin 3-O-α-L-rhamnopyranosyl-(1→2)-O-α-L-arabinopyranoside) and bisdesmosidic glycoside hederasaponin C (hederagenin 3-O-α-L-rhamnopyranosyl-(1→2)-O-α-L-arabinopyranosyl-28-О-α-L-rhamnopyranosyl-(1→4)-О-β-D-glucopyranosyl-(1→6)-О-β-D-glucopyranoside) as well as with minor monodesmosidic glycoside hederoside F (hederagenin 3-О-β-D-glucopyranosyl-(1→2)-О-β-D-glucopyranoside) have been prepared. The complexation has been investigated by methods of isomolar series in the spectrophotometric version and FT-IR spectroscopy with a universal optical attenuated total reflection (ATR) accessory. It was shown that a-hederin, hederasaponin C and hederoside F form a 1 : 1 complexes with cholesterol, having a stability constants (5.6±0.1)×104, (4.7±0.1)×104 and (6.0±0.6)×104 M–1 respectively (in 70% aqueous ethanol et 25 °С). The constants are calculated on the basis of isomolar curves. The complexes of cholesterol with ivy monodesmosidic glycosides are more stable. Intermolecular interaction in the complexes is carried out by hydrogen bonds formation of type –С=О···Н–О– (for monodesmosidic glycosides) and –(Н)О···Н–О– (for bisdesmosidic glycoside). Hydrophobic contacts of the aglycone part of glycosides (hederagenin) with a lipophilic cholesterol molecule are possible. As a result, changes in some frequencies of the absorption bands of CH bonds are observed, which was established by IR spectroscopy.

Multiscale exploration of hydrocarbons adsorption and hopping through the ZSM-5 channels - from Monte Carlo modelling to experiment

2021 ◽  
Author(s):  
Maciej Strzempek ◽  
Karolina A. Tarach ◽  
Kinga Góra-Marek ◽  
Fernando Rey ◽  
Miguel Palomino ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Ir Spectroscopy ◽  
Aliphatic Hydrocarbons ◽  
Adsorption Studies ◽  
Ft Ir ◽  
Gravimetric Adsorption ◽  
Hydrocarbons Adsorption ◽  
Ft Ir Spectroscopy

Abstract In this article the results of the statistical MC modelling corroborated by the FT-IR spectroscopy and gravimetric adsorption studies of the low aliphatic hydrocarbons in ZSM-5 (Si/Al =28 or...

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