Physico-chemical studies of sodium tetraphenylborate and tetrabutylammonium tetraphenylborate in pure nitrobenzene and nitromethane and their binaries probed by conductometry, refractometry and FT-IR spectroscopy

2012 ◽  
Vol 54 ◽  
pp. 28-34 ◽  
Author(s):  
Rajani Dewan ◽  
Mahendra Nath Roy
2005 ◽  
Vol 19 (1) ◽  
pp. 17-26 ◽  
Author(s):  
Chrystelle Lorin–Latxague ◽  
Anne–Marie Melin

Oxidative damage induced by ascorbic acid (AA) and hydrogen peroxide (H2O2) was monitored by Fourier transform infrared spectroscopy (FT‒IR); it appeared as a rapid and convenient means to follow the biochemical changes generated in the culture media of the yellow-pigmentedMicrococcus luteus. Beyond a threshold of 20 mM for AA and of 40 mM for H2O2(final concentration), antioxidant systems were overwhelmed and significant changes were observed in the bacterial spectra, particularly in the 1430–900 cm−1region; this spectral window provided large information about carboxylate groups, phosphate-carrying compounds and polysaccharides implicated in the radical process. The spectroscopic results indicated that for the same final concentration, the toxicity of H2O2was less important than that of AA towardM. luteuscells, although H2O2had a more damaging effect on proteins. Thus, FT-IR spectroscopy was an appropriate physico-chemical tool suitable in biochemical and clinical research for early characterization of any type of radical aggression, and for rapid detection of the damage intensity.


2021 ◽  
Vol 06 ◽  
Author(s):  
Mustapha Dib ◽  
Mohammed Naciri Bennani ◽  
Ouchetto Hajiba ◽  
Khadija Ouchetto ◽  
Hafid Abderrafia ◽  
...  

Background: In this study, we determined the acid neutralizing capacity (ANC) of Mg/Al-Hydrotalcite-like compounds. The MgAl-hydrotalcites were synthesized by co-precipitation method at room temperature using Mg/Al molar ratios 2 and 3. The synthesized bioactive nanomaterials were characterized by various physico-chemical techniques such as TG/dTG, DRX, FT-IR spectroscopy, BET/BHJ and MEB/EDX. The antacid activity assay was done by converting both synthesized samples into liquids, 1 g of which was added to 50 ml of deionized water at 37°C under vigorous agitation. The acid neutralizing capacity (ANC) was evaluated with 0.1N HCl. The pH was constantly measured using a pH meter and values were recorded every minute up to 35 min. In order to improve the neutralizing power of the samples, we performed on the MgAl-HT3 synthesized an exchange of chlorides by carbonates. The exchanged Mg/Al-Hydrotalcite (MgAl-HTE) shows a high acid neutralization capacity (up to 13.5 mEq/g). Objective: To synthesize an MgAl-hydrotalcite-like compounds and evaluation of their acid neutralizing capacity and thus can be good candidates for pharmaceutical applications as antacid drugs. Methods: Preparation of MgAl-hydrotalcite-like compounds by coprecipitation methods - Characterization of samples by physico-chemical techniques such as TG/dTG, DRX, FT-IR spectroscopy, BET/BHJ and MEB/EDX. - Evaluation of acid neutralizing capacity by titration procedure (Dose-titration) . Results: This protocol describes the preparation of MgAlhydrotalcite-like using the classical coprecipitation method. The synthesized samples were characterized by various physicochemical techniques such as TG/dTG, DRX, FT-IR spectroscopy, BET/BHJ and MEB/EDX. The as-synthetized samples were used for the evaluation of their acid-neutralizing capacity (ANC). Further, an exchanged MgAl-Hydrotalcite with carbonate was described for the purpose to increases the acid-neutralizing capacity. Conclusion: In summary, this study describes a simple synthesis of MgAl-Hydrotalcites compounds by a co-precipitation method at constant pH around 10, with a ratio Mg/Al = 3 and 2 (referred to as MgAl-HT3 and MgAl-HT2). An exchange of the chlorides (not eliminated by washing) by the carbonates was carried out on hydrotalcite with a ratio Mg/Al = 3 and the solid obtained was named MgAl-HT3E. The materials MgAl-HT2, MgAl-HT3 and MgAl-TH3E were used to evaluate their antacid activity. To this end, a study was conducted to determine the acid neutralizing capacity (ANC). As a result, the MgAl-HT3E was able to increase acid neutralizing capacity and maintaining an ideal pH. These results could be interesting to prepare novel antacid drugs (due to the low cost of synthesized materials) essentially the hydrotalcite of Mg/Al ratio equal to 3 because of its relatively slow kinetics of releasing basic species and therefore of its beneficial action as an antacid.


Author(s):  
Maciej Strzempek ◽  
Karolina A. Tarach ◽  
Kinga Góra-Marek ◽  
Fernando Rey ◽  
Miguel Palomino ◽  
...  

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...


2021 ◽  
Vol 22 (4) ◽  
pp. 2191
Author(s):  
Jing Huang ◽  
Nairveen Ali ◽  
Elsie Quansah ◽  
Shuxia Guo ◽  
Michel Noutsias ◽  
...  

In recent decades, vibrational spectroscopic methods such as Raman and FT-IR spectroscopy are widely applied to investigate plasma and serum samples. These methods are combined with drop coating deposition techniques to pre-concentrate the biomolecules in the dried droplet to improve the detected vibrational signal. However, most often encountered challenge is the inhomogeneous redistribution of biomolecules due to the coffee-ring effect. In this study, the variation in biomolecule distribution within the dried-sample droplet has been investigated using Raman and FT-IR spectroscopy and fluorescence lifetime imaging method. The plasma-sample from healthy donors were investigated to show the spectral differences between the inner and outer-ring region of the dried-sample droplet. Further, the preferred location of deposition of the most abundant protein albumin in the blood during the drying process of the plasma has been illustrated by using deuterated albumin. Subsequently, two patients with different cardiac-related diseases were investigated exemplarily to illustrate the variation in the pattern of plasma and serum biomolecule distribution during the drying process and its impact on patient-stratification. The study shows that a uniform sampling position of the droplet, both at the inner and the outer ring, is necessary for thorough clinical characterization of the patient’s plasma and serum sample using vibrational spectroscopy.


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