Infrared Study of Phosphorous Oxychloride and Organophosphorus Compounds Containing the P(=O)Cl2 Group in Dilute Solvent Systems

1992 ◽  
Vol 46 (10) ◽  
pp. 1552-1563 ◽  
Author(s):  
R. A. Nyquist ◽  
C. W. Puehl
Keyword(s):  
Organophosphorus Compounds ◽  
Solvent System ◽  
Rotational Isomer ◽  
Infrared Study ◽  
Normal Vibrations ◽  
Phosphorous Oxychloride ◽  
Solvent Systems

The present study has shown that some normal vibrations shift to lower frequency while others shift to higher frequency as the mole % of the solvent system increases. The vP=O mode for compounds containing the P(=O)Cl2 group shifts to lower frequency with increase in the mole % CHCl3/CCl4. The P=O group is believed to be complexed with the solvent system. Both the vasym.PCl2 and vsym.PCl2 modes shift to higher frequency as the mole % CHCl3/CCl4 increases. The application of IR and different solvent systems aids in assigning rotational isomer band pairs.

Infrared Study of Benzaldehyde and 4-Substituted Benzaldehydes in Carbon Tetrachloride and/or Chloroform Solutions: The Carbonyl Group

1991 ◽  
Vol 45 (10) ◽  
pp. 1641-1648 ◽  
Author(s):  
Richard A. Nyquist ◽  
Sam E. Settineri ◽  
Davin A. Luoma
Keyword(s):  
Carbon Tetrachloride ◽  
Carbonyl Group ◽  
Functional Groups ◽  
Functional Group ◽  
Solvent System ◽  
Infrared Study ◽  
Solvent Systems ◽  
Substituted Benzaldehydes ◽  
Uniform Manner ◽  
Acceptor Numbers

The carbonyl stretching mode of 4- x-benzaldehydes increases in frequency as the mole % CHCl3/CCl4 decreases and as the value of σP− or σRO for the 4- x atom or group increases. Other functional groups such as OH, NO2 and CN are also affected by interaction with the CHCl3 and/or CCl4 solvent system. Other solvents may interact differently with each functional group so that, say, vC=O vs. σP−, σRO, or solvent acceptor numbers (AN) may not correlate in a uniform manner in all solute/solvent systems.

Infrared Study of Some Organophosphorus Esters in Carbon Tetrachloride and/or Chloroform 1% Solutions

1992 ◽  
Vol 46 (10) ◽  
pp. 1564-1574 ◽  
Author(s):  
R. A. Nyquist ◽  
C. W. Puehl
Keyword(s):  
Carbon Tetrachloride ◽  
Functional Groups ◽  
Solvent System ◽  
Infrared Study ◽  
Solvent Interaction ◽  
Rotational Isomers ◽  
Solvent Systems ◽  
Solute Solvent Interaction ◽  
Organophosphorus Esters

Solvent systems such as CHCl3/CCl4 or CDCl3/CCl4 are useful in showing that organophosphorus esters do exist as rotational isomers in solution. The functional groups such as P=O and POR in organophosphorus esters are the sites of solute/solvent interaction, since their group frequencies are more affected than group frequencies arising primarily within the R group of the organophosphorus esters. This study also shows that different complexes are formed between the solute and solvent systems as well as within the solvent system as the mole % CHCl3/CCl4 or CDCl3/CCl4 increases.

OPTIMIZATION OF THIN LAYER CHROMATOGRAPHY METHODS FOR SEPARATION AND IDENTIFICATION OF ANTIDEPRESSANTS IN THEIR MIXTURE

2014 ◽  
Vol 21 (1) ◽  
pp. 11-15
Author(s):  
Daiva Kazlauskienė ◽  
Guoda Kiliuvienė ◽  
Palma Nenortienė ◽  
Giedrė Kasparavičienė ◽  
Ieva Matukaitytė
Keyword(s):  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Solvent System ◽  
Ammonia Solution ◽  
Relative Standard ◽  
Rf Values ◽  
Solvent Systems ◽  
Paroxetine Hydrochloride ◽  
Fluvoxamine Maleate ◽  
Layer Chromatography

By conducting the toxicological analysis it is meaningful to determine the analytical system that could identify simultaneously several medicinal preparations quickly and precisely. The purpose of this work was to create and validate the method of thin-layer chromatography that would be suitable to separate the components of antidepressant mixture (amitriptyline hydrochloride, paroxetine hydrochloride, sertraline hydrochloride, fluvoxamine maleate and buspirone hydrochloride) and to identify them. The system was validated with regard to the sensitivity, repetition of data, resistance and particularity. The solvent systems with potential of high separation of components in their mixture were created: acetonitrile, methanol, ammonia solution 25 percent (85:10:5); acetonitrile, methanol, ammonia solution 25 percent (75:20:5); dichlormethane, 1,4-dioxane, ammonia solution 25 percent (50:45:5); dichlormethane, 1,4-dioxane, ammonia solution 25 percent (42:55:3); trichlormethane, 1,4-dioxane, ammonia solution 25 percent (25:70:5); trichlormethane, 1,4-dioxane, ammonia solution 25 percent (60:36:4). One of the most suitable solvent systems for separation of the analyzed mixture (sertraline, amitriptyline, paroxetine, buspirone, fluvoxamine) was determined – acetonitrile, methanol, ammonia solution 25 percent (85:10:5). When this solvent system was used, the average Rf values of the analyzed compounds differed the most. Validation was conducted – the relative standard deviation (RSD, percent) of the average Rf value of the analyzed compounds varied from 0,6 to 1,8 percent and did not exceed the permissible error of 5 percent. The sensitivity of methodology was determined by assessing the intensity of the mixture’s spots on the chromatographic plate. The detection limit of buspirone was 0,0012 µg; sertraline – 0,0008 µg; amitriptyline – 0,0004 µg; fluvoxamine – 0,0004 µg; paroxetine – 0,0008 µg. The resistance of results to the changed conditions – it was determined that when the amounts of the solvents acetonitrile and methanol were increased or decreased to two milliliters, the average Rf values of the analyzed compounds did not change statistically significantly

Ultrasound-Assisted Oxidative Desulfurization of Diesel Fuel in H2O2/Heteropoly Acid/Solvent System

2014 ◽  
Vol 1033-1034 ◽  
pp. 85-89 ◽  
Author(s):  
Guo Xian Yu ◽  
Qian Zhong ◽  
Mei Jin ◽  
Ping Lu
Keyword(s):  
Sulfur Content ◽  
Ultrasonic Irradiation ◽  
Diesel Fuel ◽  
Oxidation Reaction ◽  
Heteropoly Acid ◽  
Oxidative Desulfurization ◽  
Solvent System ◽  
Oxidative Reaction ◽  
Solvent Systems ◽  
Ultrasound Assisted

Ultrasound-assisted oxidative desulfurization (UAODS) of diesel fuel in H2O2/Heteropoly acid/Solvent systems, was investigated. Effects of solvent, catalyst, ultrasound and reaction temperature on the oxidation desulfurization of diesel fuel were investigated. When MPA/oil was 2%wt, methanol/diesel fuel was 20%wt, ultrasound power was 400 W and ultrasound time was 10 min, the sulfur content of diesel fuel was decreased from 211 ppm to 19 ppm. The use of ultrasonic irradiation in H2O2/Heteropoly acid/Solvent system significantly improved the efficiency of the oxidation reaction, and solvent was helpful to make the oxidative reaction happen in the same one phase.

Molecular Dynamics Study of Candida rugosa Lipase in Water, Methanol, and Pyridinium Based Ionic Liquids

2021 ◽  
Vol 874 ◽  
pp. 88-95
Author(s):  
Oktavianus Hendra Cipta ◽  
Anita Alni ◽  
Rukman Hertadi
Keyword(s):  
Molecular Dynamics ◽  
Ionic Liquid ◽  
Ionic Liquids ◽  
Candida Rugosa ◽  
Solvent System ◽  
Dynamics Simulation ◽  
Initial Structure ◽  
Enzymatic Reactions ◽  
Solvent Systems ◽  
To Come

The structure of Candida rugosa lipase can be affected by solvents used in the enzymatic reactions. Using molecular dynamics simulation as a tool to study the Candida rugosa lipase structure, we studied the effect of various solvent systems, such as water, water-methanol, and water-methanol-ionic liquid. These solvent systems have been chosen because lipase is able to function in both aqueous and non-aqueous medium. In this study, pyridinium (Py)-based ionic liquids were selected as co-solvent. The MD simulation was run for 50 nanoseconds for each solvent system at 328 K. In the case of water-methanol-ionic liquids solvent systems, the total number of the ionic liquids added were varied: 222, 444, and 888 molecules. Water was used as the reference solvent system. The structure of Candida rugosa lipase in water-methanol system significantly changed from the initial structure as indicated by the RMSD value, which was about 6.4 Å after 50 ns simulation. This value was relatively higher compared to the other water-methanol solvent system containing ionic liquid as co-solvent, which were 2.43 Å for 4Py-Br, 2.1 Å for 8Py-Br, 3.37 Å for 4Py-BF4 and 3.49 Å for 8Py-BF4 respectively. Further analysis by calculating the root mean square fluctuation (RMSF) of each lipase residue found that the presence of ionic liquids could reduce changes in the enzyme structure. This happened because the anion component of the ionic liquid interacts relatively more strongly with residues on the surface of the protein as compared to methanol, thereby lowering the possibility of methanol to come into contact with the protein.

scholarly journals Rhodamine-Sulphuric Acid -A New Visualization Reagent for the Determination of Sucralose by HPTLC

2010 ◽  
Vol 7 (s1) ◽  
pp. S559-S565 ◽  
Author(s):  
Mohd Idris ◽  
Seema Srivastava ◽  
T. R. Baggi ◽  
S. K. Shulka ◽  
A. K. Ganjoo
Keyword(s):  
Sulphuric Acid ◽  
Limit Of Detection ◽  
Solvent System ◽  
Artificial Sweetener ◽  
Yellow Fluorescence ◽  
Relative Standard ◽  
Golden Yellow ◽  
Solvent Systems ◽  
Olive Green

Sucralose a UV-visible inactive compound was separated on silica gel plate without any plate treatment prior to analysis, derivatized with rhodamine - sulphuric acid reagent and detected densitometrically at 456 nm as olive green band. With this reagent sucralose also shows golden yellow fluorescence at 366 nm. Two new solvent systemsi.e. chloroform: methanol: toluene (v/v 5:3.5:1.5) (solvent system-I) and chloroform: ethanol: benzene (v/v 5:3:2) (solvent system-II) were developed and giving Rfvalues of 0.62 and 0.45 respectively. The method was found to be sensitive with good limit of detection (LOD) for two solvent systems. The method imparts specificity to the method as at 456 nm sucralose only gives olive green color spots where as other artificial sweeteners did not show any response to this reagent, where as carbohydrates gives black color spots. Similarly sucralose gives golden yellow fluorescence at 366 nm which is not given by any other artificial sweetener. The method was highly reproducible with relative standard deviation (RSD)≤3% (n=3) and was applied for the determination of sucralose in different matrices like cola drinks, lemon juices, sugar free sweets, tabletop sweeteners etc.etc.

scholarly journals Thin Layer Chromatographic Analysis of Food Colorants from Three Morphotypes of Annatto (Bixa orellana L.)

2013 ◽  
Vol 2 (1) ◽  
pp. 7-12
Author(s):  
Hari Pada Seal ◽  
Mohammad Amdad Ali ◽  
Md Usuf Ali ◽  
Mosammat Hasina Akhter ◽  
Fowzia Sultana
Keyword(s):  
Thin Layer ◽  
Chromatographic Analysis ◽  
Mixed Solvent ◽  
Solvent System ◽  
Bixa Orellana ◽  
Solvent Extraction Method ◽  
Solvent Systems ◽  
Carrier Solvent ◽  
Thin Layer Chromatographic Analysis ◽  
Layer Chromatography

This article describes a simple solvent extraction method for the extraction of colorants from the three morphotypes such as, (Morphotype-1 (M1), Morphotype-2 (M2), and Morphotype- 3 (M3) of Annatto (Bixa orellana L.) seeds, and their separation, vivid, and qualitative demonstration by thin-layer chromatography. Several solvent systems (hexane, chloroform, acetone, ethanol, and a mixed-solvent having composition of CHCl3/C2H5OH/CH3COOH (80:2:1)) were applied for extraction of colored components. It was observed that a large portion of colorants was extracted by chloroform. Its effluent was deep brick red in color and transparent. Furthermore, various carrier solvent systems (Benzene-Ethyl acetate) were used to separate the components from the extracts. Carrier solvent system with the ratio of 7:3 was found as superior solvent for chloroform extracts. Three colored-spots were observed for all morphotypes. Among them, the first one was yellow colored having very low polarity and the second and third spots were both redbrick colored having medium and higher polarity respectively. In addition, for M1 no colorless-spot was observed in low and medium polar systems, revealing that the amount of wax and gum were minimum in the extract and superior morphotype among the three. DOI: http://dx.doi.org/10.3329/ijarit.v2i1.13987 Int. J. Agril. Res. Innov. & Tech. 2 (1): 7-12, June, 2012

Infrared Study of Ethylene Carbonate in Various Solvents and Solvent Systems

1991 ◽  
Vol 45 (7) ◽  
pp. 1075-1084 ◽  
Author(s):  
R. A. Nyquist ◽  
S. E. Settineri
Keyword(s):  
Ethylene Carbonate ◽  
Infrared Study ◽  
Solvent Systems

Isolation and Purification of Five Phloroglucinol Derivatives From Agrimonia Pilosa Ledeb by Counter-Current Chromatography Using Non-Aqueous Solvent Systems

2020 ◽  
Author(s):  
Lulu Fu ◽  
Chenghua Lu ◽  
Shengqiang Tong ◽  
Min Xu ◽  
Lan Tang ◽  
...  
Keyword(s):  
Closed Loop ◽  
Solvent System ◽  
The Other ◽  
Second Step ◽  
Two Phase ◽  
Isolation And Purification ◽  
Aqueous Solvent ◽  
Phloroglucinol Derivatives ◽  
Solvent Systems ◽  
Counter Current

Abstract Five non-polar phloroglucinol derivatives, viz. pseudo-aspidin, α-kosin and agripinol A-C were isolated and purified from Agrimonia pilosa Ledeb by semi-preparative counter-current chromatography. The separation was performed by a two-step elution with non-aqueous solvent systems. In the first step, an elution mode of a two-phase solvent system consisting of n-hexane-acetonitrile-dichloromethane-methanol (6:6:0.5:0.5, v/v/v/v) was used. We obtained sample Ι containing three components (47.0 mg) and sample ΙΙ containing two components (24.8 mg) from crude extract (371.0 mg). In the second step, sample Ι was successfully separated by closed-loop recycling mode with a solvent system consisting of n-hexane-acetonitrile-dichloromethane (10:7:3, v/v/v), yielding 17.8 mg of pseudo-aspidin, 18.5 mg of α-kosin and 6.4 mg of agripinol A. The other two compounds—8.7 mg of agripinol B and 13.6 mg of agripinol C—were obtained from sample ΙΙ in the same manner. All the isolated compounds had a high purity exceeding 95%.

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