Influence of KBr conditioning on the infrared hydroxyl-stretching region of saponites

Clay Minerals ◽  
1999 ◽  
Vol 34 (3) ◽  
pp. 439-445 ◽  
Author(s):  
M. Pelletier ◽  
L. J. Michot ◽  
O. Barrès ◽  
B. Humbert ◽  
S. Petit ◽  
...  
Keyword(s):  
Ir Spectroscopy ◽  
Ir Spectra ◽  
Clay Minerals ◽  
Diffuse Reflectance ◽  
Layer Charge ◽  
Tetrahedral Sheet ◽  
Stretching Vibration ◽  
Sheet Charge

AbstractIn order to assess the influence of tetrahedral sheet charge on the hydroxyl-stretching vibration in clay minerals, a series of synthetic Na-saponites, with increasing layer charge, was studied by infrared (IR) spectroscopy. When recorded after KBr dilution either in transmission or diffuse reflectance, the IR spectra exhibit a component at ~3710 cm-1, the intensity of which increases linearly with increasing layer charge. When experiments are carried out without any dilution of the samples, this component is not observed, suggesting a Na+/K+ exchange upon mixing of the sample with KBr. The spectra obtained for K-saponite confirm this exchange. This shows that the dilution procedure can lead to serious misinterpretations of IR spectra in the OH-stretching region.

The molecular conformations of the stereoisomers of 4-methyl-5,6-benzo-2-oxo-1,3,2-dioxathiepin and of the 4,7-dimethyl derivative

1983 ◽  
Vol 61 (10) ◽  
pp. 2244-2253 ◽  
Author(s):  
A. Lachapelle ◽  
M. St-Jacques ◽  
A. C. Guimaraes ◽  
P. De Almeida
Keyword(s):  
Low Temperature ◽  
Ir Spectroscopy ◽  
Ir Spectra ◽  
Nmr Spectra ◽  
Dynamic Properties ◽  
Substituent Effects ◽  
Spectroscopy Analysis ◽  
Molecular Conformations ◽  
Methyl Group ◽  
Stretching Vibration

The conformational and dynamic properties of the stereoisomers of 4-methyl-5,6-benzo-2-oxo-1,3,2-dioxathiepin (5) and of the 4,7-dimethyl derivative (6) have been investigated by 1H and 13C dnmr methods, as well as by ir spectroscopy. Analysis of the nmr spectra at low temperature (−125 °C), together with the conformational interpretation of the stretching vibration bands of the S = O bond in the ir spectra, indicate that the most stable conformations detected for solutions in CHF2Cl are C-a (82%) and TB-t-Mec (18%) for 5a, TB-c-Mec, (96%) and TB-c-Mea, (4%) for 5b, C-a for 6a, TB-t-Mec, c-Mec, for 6b and C-e for 6c. The substituent effects of a methyl group at the benzylic position on both the conformational and dynamic properties of the seven-membered sulfite are discussed.

The IR spectra of 2-haloethylamines V. The intensity of the C-Cl and C-Br stretching vibration bands in Kbr disks

1973 ◽  
Vol 18 (6) ◽  
pp. 750-753
Author(s):  
L. V. Sennitskaya ◽  
B. S. Kikot' ◽  
O. M. Belokon' ◽  
Yu. A. Pentin
Keyword(s):  
Ir Spectra ◽  
Stretching Vibration

Applications of Diffuse Reflectance FT-IR to Pigment Photodecomposition in Paint

1982 ◽  
Vol 36 (2) ◽  
pp. 155-157 ◽  
Author(s):  
D. B. Chase ◽  
R. L. Amey ◽  
W. G. Holtje
Keyword(s):  
Ir Spectroscopy ◽  
Infrared Spectra ◽  
Diffuse Reflectance ◽  
Spectral Subtraction ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

Diffuse reflectance FT-IR spectroscopy is used to obtain infrared spectra of paints directly on paper panels. The binder contribution to the spectrum can be effectively eliminated by spectral subtraction and the spectra of photodecomposition products are obtained. Comparison with reference spectra allows the determination of the photodecomposition mechanism.

scholarly journals Evaluation of solubility and histological effect of 11-keto-β-Boswellic acid on the diabetic mice liver using FTIR-PCA analysis and microscopy

2021 ◽  
Author(s):  
I.S. Al-Amri ◽  
F. Mabood ◽  
I.T. Kadim ◽  
A.Y. Alkindi ◽  
A. Al-Harrasi ◽  
...  
Keyword(s):  
Ir Spectroscopy ◽  
Ir Spectra ◽  
Liver Tissue ◽  
Diabetic Control ◽  
Control Group ◽  
Diabetic Mice ◽  
Boswellic Acid ◽  
Ft Ir ◽  
Mice Liver ◽  
Ft Ir Spectroscopy

ABSTRACTThis study was designed to develop a rapid, sensitive, accurate, and inexpensive Fourier Transform Infrared Reflectance (FT-IR) Spectroscopy coupled with Principle Component Analysis (PCA) as a detection technique to evaluate the solubility of 11-Keto-β-Boswellic acid (KBA), from the gum resin extracted from the Omani frankincense, (Boswellia sacra) in the liver of STZ induced diabetic mice. This study also investigated the effect of KBA on the histological changes of hepatocytes of diabetic mice. Liver tissue samples from three groups of mice included normal control group, diabetic control group and diabetic group treated IP with KBA were scanned with FT-IR spectrophotometer in the reflection mode. FT-IR Spectra were collected in the wavenumber range from 400 to 4000cm-1 using ATR accessorry. The results of FT-IR Spectra were analyzed by using multivariate method Principle Component Analysis. The PCA score plot is an exploratory multivariate method indicated that there was a complete segregation among the three groups of liver samples based on change in variation of position of wavenumber in FT-IR spectra, which revealed that there is a clear effect of KBA solubility on treatments. The histological features showed an improvement in the liver tissues with normal structures of hepatocytes with exhibiting mild vacuolations in their cytoplasm. In conclusion, reflectance FT-IR spectroscopy coupled with PCA could be deployed as a new detection method for rapid, low cost and non-destructive method for evaluating of treatment effects in diseased liver tissue based on the solubility of KBA. Histological findings demonstrated the protective effective of KBA on improving the morphology of liver tissue in diabetic mice which resulted in complete recovery to the damage observed in diabetic control group.Summary StatementReflectance FT-IR spectroscopy coupled with PCA has been deployed as a new rapid, inexpensive and non-destructive detection method to examine the solubility of 11-keto-β-Boswellic acid (KBA) in streptozotocin (STZ) induced-diabetes mice liver tissue following intraperitoneal treatment. Moreover, microscopic study of liver tissue histopathology revealed that KBA has a protecting effect against STZ damage.

scholarly journals Effect of slope aspect on transformation of clay minerals in Alpine soils

Clay Minerals ◽  
2007 ◽  
Vol 42 (3) ◽  
pp. 373-398 ◽  
Author(s):  
M. Egli ◽  
A. Mirabella ◽  
G. Sartori ◽  
D. Giaccai ◽  
R. Zanelli ◽  
...  
Keyword(s):  
Clay Minerals ◽  
Soil Profile ◽  
Water Flux ◽  
Layer Charge ◽  
Slope Aspect ◽  
X Ray Diffraction ◽  
The South ◽  
Octahedral Sheet ◽  
The North ◽  
Low Charge

AbstractTwo soil profile sequences on paragneiss debris in the Val di Rabbi (Northern Italy) along an altitude gradient ranging from 1200 to 2400 m a.s.l. were studied to evaluate the effect of aspect on the weathering of clay minerals. All the soils had a coarse structure, a sandy texture and a low pH. Greater weathering intensities of clay-sized phyllosilicates (greater content of smectites) were observed in soils on the north-facing slope. On the south-facing slope, smectite was found only in the surface horizon of the soil profile at the highest altitude. Hot citrate treatment of north-facing soils revealed the presence of low-charged 2:1 clay minerals, the expansion of which was hindered in the untreated state by interlayered polymers. However, the hot citrate treatment encountered some problems with the samples of the south-facing soils: as confirmed by Fourier transform infrared spectroscopy, the hot citrate treatment was unable to remove all interlayer Al polymers. The 2:1 phyllosilicates were not expanded by ethylene glycol solvation in several samples, although thermogravimetric analyses indicated the presence of clay minerals with interlayer H2O. At the same time, the collapse of clay minerals to 1.0 nm following K-saturation was evident. Theoretically, this should indicate that 2:1 phyllosilicates had no evident substitution of trioctahedral cations (Mg2+, Fe2+) by dioctahedral cations (Al3+ and Fe3+). X-ray diffraction analysis of the d060 region and determination of the layer charge of clay minerals by the long-chain (C18) alkylammonium ion, however, did not confirm this. A transformation from trioctahedral to dioctahedral species was observed and low-charge clay minerals (ξ ~0.30) were identified in the surface horizons of the south-facing sites. In the south-facing soils, the podzolization process was less pronounced because of a lower water flux through the soil and probably less complexing organic molecules that would remove the interlayer polymers. Besides the eluviation process, clay minerals underwent a process of ionic substitutions in the octahedral sheet that led to the reduction of the layer charge. This process was more obvious in the north-facing sites.

scholarly journals Application of FT-IR spectroscopy in detection of food hydrocolloids  in confectionery jellies and food supplements

2013 ◽  
Vol 19 (No. 2) ◽  
pp. 51-56 ◽  
Author(s):  
J. Čopíková ◽  
M. Černá ◽  
M. Novotná ◽  
J. Kaasová ◽  
A. Synytsya
Keyword(s):  
Ir Spectroscopy ◽  
Ir Spectra ◽  
Food Products ◽  
Food Supplements ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

FT-IR spectra of isolated high molecule fractions were measured and used for identification of food hydrocolloids in confectionery jellies and food supplements. The simple comparison of spectra of standards and samples proved that this technique is useful for the monitoring of food hydrocolloids in particular food products.

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