Chromatographic analysis of the ethyl acetate-toluene-butyl acetate mixture used for the lacquering of cellophane

1978 ◽  
Vol 10 (2) ◽  
pp. 198-200
Author(s):  
V. F. Mironenko ◽  
V. S. Prokop'eva ◽  
L. K. Shirshova ◽  
G. I. Korchevskaya
Keyword(s):  
Ethyl Acetate ◽  
Chromatographic Analysis ◽  
Butyl Acetate ◽  
Acetate Mixture

The Flavor Property of Soft Cheese Fermented by Two Stains of Streptococcus thermophilus and Made of Reconstituted Milk

2011 ◽  
Vol 396-398 ◽  
pp. 1536-1540
Author(s):  
Yan Hua Li ◽  
Lan Wei Zhang ◽  
Wei Jun Wang ◽  
Li Li Zhang ◽  
Xue Han ◽  
...  
Keyword(s):  
Ethyl Acetate ◽  
Butyl Acetate ◽  
Streptococcus Thermophilus ◽  
Acetate Methyl ◽  
Soft Cheese ◽  
Significant Difference ◽  
Cheese Volatiles ◽  
Methyl Butyrate ◽  
Reconstituted Milk ◽  
The Impact

The effect of reconstituted milk inoculation with Streptococcus thermophilus TM11 and Streptococcus thermophilus SP 1.1 on soft cheese volatiles was investigated. The impact flavors of 2,3-butanedione, 2,3-pentanedione, ethyl acetate, methyl butyrate, ethyl butyrate, butyl acetate and butyric acid were only detected in the fermented cheeses. Levels of diketones were higher in the cheeses fermented by mixed cultures than single culture, while levels of esters except ethyl acetate and butyl acetate showed an opposite tendency. There was significant difference in the levels of 2-hexenal and 2-nonenal among the cheeses. Other compounds originated from lipid oxidation, Strecker degradation, biosynthesis and forages were not significantly influenced by milk inoculation with Streptococcus thermophilus.

Chromatography Using Ternary Water–Acetonitrile–Ethyl Acetate Mixture as a Carrier Solution on a Microchip Incorporating Microchannels

2012 ◽  
Vol 41 (11) ◽  
pp. 1448-1450 ◽  
Author(s):  
Takafumi Matsuda ◽  
Naoya Jinno ◽  
Kenichi Yamashita ◽  
Hideaki Maeda ◽  
Akihiro Arai ◽  
...  
Keyword(s):  
Ethyl Acetate ◽  
Carrier Solution ◽  
Acetate Mixture ◽  
Ethyl Acetate Mixture

scholarly journals Areas of energy advantage for flowsheets of separation modes for mixtures containing components with similar volatilities

2020 ◽  
Vol 15 (3) ◽  
pp. 7-20
Author(s):  
M. E. Peshekhontseva ◽  
M. A. Maevskiy ◽  
I. S. Gaganov ◽  
A. V. Frolkova
Keyword(s):  
Ethyl Acetate ◽  
Butyl Acetate ◽  
Energy Savings ◽  
Equilibrium Diagram ◽  
Distribution Coefficients ◽  
Local Composition ◽  
Component Distribution ◽  
Boiling Points ◽  
Relative Errors ◽  
Energy Advantage

Objectives. The conditions for the effective application of the sharp distillation technique (without a component distributed between the distillate and bottom flows) for the separation of quaternary zeotropic mixtures containing components with similar volatilities were determined. The area of energy advantage for the flowsheet based on the preliminary fractionation of the mixture, compared with the flowsheet, the first distillation column of which works based on the indirect separation mode, was identified for an ethyl acetate–benzene–toluene–butyl acetate system. Energy savings of up to 20% were achieved. The direct and indirect distillation modes can become competitive when the point of the original composition is located near single K-surfaces or in a region with a different ratio of distribution coefficients. Sharp distillation is not suitable for the separation of a mixture containing a pair of components exhibiting relative unity volatility with medium boiling points.Methods. The mathematical modeling in the Aspen Plus V.10.0 software package was chosen as the research method. The simulation was based on the Wilson local composition equation. The relative errors in the description of the phase equilibrium did not exceed 3%.Results. The structure of the vapor–liquid equilibrium diagram and diagram of surfaces of the unit component distribution coefficients were studied for the ethyl acetate–benzene–toluenebutyl acetate and acetone–toluene–butyl acetate–o-xylene systems. Flowsheets based on the sharp, indirect (both systems), or direct (second system) distillation modes were proposed. The distillation process was simulated, and the parameters of the column work were determined (the quality of the substances meets the State Standard requirements of the Russian Federation for minimal energy consumption).Conclusions. Recommendations regarding the use of sharp distillation for the separation of quaternary mixtures containing components with similar volatilities were devised.

A Qualitative Gas Chromatographic Analysis of Substituted 5,6-Dihydroxyindoles from the Urine of Patients with Melanoma

1981 ◽  
Vol 67 (4) ◽  
pp. 325-332 ◽  
Author(s):  
Stanislav Pavel ◽  
Frits A. J. Muskiet ◽  
Alena Budešínská ◽  
Jirí Duchon
Keyword(s):  
Ethyl Acetate ◽  
Chromatographic Analysis ◽  
Helix Pomatia ◽  
Nitrogen Atmosphere ◽  
Spectrometric Analysis ◽  
Gas Chromatographic Analysis ◽  
Indolic Compounds ◽  
Hydrolysis Of ◽  
Ethyl Acetate Extracts ◽  
Chromatographic Mass

A qualitative gas chromatographic analysis of trimethylsilylated ethyl acetate extracts of melanotic urine revealed 5 indolic compounds, which have been identified as substituted 5,6-dihydroxyindoles. Ethyl acetate extracts of melanotic urines at pH 2.0 contained isomeric 5-hydroxy-6-methoxy and 6-hydroxy-5-methoxy-indolyl-2-carboxylic acids which were not separable under the conditions used. A careful hydrolysis of melanotic urine with a Helix pomatia preparation followed by extraction at pH 6.5 in a nitrogen atmosphere released 3 additional indolic compounds from their conjugated form. Using gas chromatographic-mass spectrometric analysis they were identified as 5-hydroxy-6-methoxy, 6-hydroxy-5-methoxyindole and 5,6-dihydroxyindole.

scholarly journals Chromatographic Analysis and Antioxidant Capacity of Tabernaemontana catharinensis

2014 ◽  
Vol 9 (1) ◽  
pp. 1934578X1400900 ◽  
Author(s):  
Aline A. Boligon ◽  
Mariana Piana ◽  
Thiago G. Schawnz ◽  
Romaiana P. Pereira ◽  
João B. T. Rocha ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Ethyl Acetate ◽  
Antioxidant Capacity ◽  
Crude Extract ◽  
Chromatographic Analysis ◽  
Thiobarbituric Acid ◽  
Stem Bark ◽  
Total Phenols ◽  
Dpph Assay ◽  
Effective Agent

In this study we evaluated the composition of the crude extract and fractions of Tabernaemontana catharinensis (Apocynaceae) by HPLC/DAD and GC/MS. We also tested the antioxidant capacity and investigated the contents of polyphenols, flavonoids, tannins and alkaloids of T. catharinensis stem bark. The extract and fractions showed inhibition against thiobarbituric acid reactive species (TBARS), in the following order: ethyl acetate (IC50 = 4.7 ± 0.2 μg/mL) > dichloromethane (23.9 ± 1.1 μg/mL) > n-butanolic (25.2 ± 0.4 μg/mL) > crude extract (38.0 ± 0.07 μg/mL). Moreover, the DPPH assay, presented IC50 values ranged from 5.6 ± 0.6 to 30.3 ± 1.3 μg/mL. Contents of total phenols, flavonoids, tannins and alkaloids of T. catharinensis followed the order: ethyl acetate > n-butanolic > dichloromethane fractions > crude extract. HPLC/DAD analyses indicated that gallic, chlorogenic and caffeic acids, and rutin, quercetin and kaempferol are components of the species. Taken together, the results suggest that T. catharinensis could be considered an effective agent in the prevention of diseases associated with oxidative stress.

scholarly journals Preparation of tert-Butyl 6-Aminopenicillanate and its 6-Oxo and 6-Diazo Derivatives

1999 ◽  
Vol 23 (4) ◽  
pp. 270-271
Author(s):  
Grigory Veinberg ◽  
Maxim Vorona ◽  
Dan Musel ◽  
Nora Grigan ◽  
Edmunds Lukevics
Keyword(s):  
Butyl Acetate ◽  
Butyl Ester ◽  
Tert Butyl ◽  
Acetate Mixture

A 1:1 1,4-dioxane– tert-butyl acetate mixture and BF3 etherate were used for an effective 6-aminopenicillanic acid conversion into the tert-butyl ester (64 ± 3% yield) which could be easily transformed into tert-butyl 6-oxo- and 6-diazo-penicillanates.

Vapor–liquid equilibria for the binary mixtures of 2,3-butanediol with n-butanol, n-butyl acetate, and ethyl acetate at 101.3kPa

2007 ◽  
Vol 262 (1-2) ◽  
pp. 169-173 ◽  
Author(s):  
Yan-Yang Wu ◽  
Jia-Wen Zhu ◽  
Kui Chen ◽  
Bin Wu ◽  
Ya-Ling Shen
Keyword(s):  
Ethyl Acetate ◽  
Binary Mixtures ◽  
Butyl Acetate ◽  
Vapor Liquid Equilibria ◽  
Vapor Liquid

Vapor-liquid equilibrium of ethanol/ethyl acetate mixture in ultrasonic intensified environment

2014 ◽  
Vol 31 (5) ◽  
pp. 875-880 ◽  
Author(s):  
Taha Mahdi ◽  
Arshad Ahmad ◽  
Adnan Ripin ◽  
Mohamed Mahmoud Nasef
Keyword(s):  
Ethyl Acetate ◽  
Liquid Equilibrium ◽  
Vapor Liquid Equilibrium ◽  
Acetate Mixture ◽  
Ethyl Acetate Mixture ◽  
Vapor Liquid

Kinetic medium effects. III. Solvent effects on A1 and A2 Hydrolyses in water-dimethyl sulphoxide mixtures

1967 ◽  
Vol 20 (9) ◽  
pp. 1815 ◽  
Author(s):  
BG Cox ◽  
PT McTigue
Keyword(s):  
Ethyl Acetate ◽  
Solvent Effect ◽  
Activity Coefficients ◽  
Solvent Effects ◽  
Butyl Acetate ◽  
Solvent System ◽  
Solvent Composition ◽  
Dimethyl Sulphoxide ◽  
Medium Effects ◽  
System Activity

The relative rates of the concurrent A1 and A2 hydrolyses of t-butyl acetate have been measured as a function of solvent composition in water-dimethyl sulphoxide (DMSO) mixtures. A large difference in solvent effect is observed, which correlates well with observed solvent effects on ethyl acetate (A2) and acetal (Al) hydrolyses in the same solvent system. Activity coefficients have been measured for t-butyl acetate, ethyl acetate, and acetal in various water-DMSO mixtures.

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