Kinetics of Micellar Effect of Non-Ionic Surfactant on Oxidative Degradation of Ciprofloxacin

Oxidative degradation kinetics of leading fluoroquinolone family drug ciprofloxacin (CIP) by chloramine-T (CAT) in TX-100 micelle media was studied spectrophotometrically at 275 nm and 298 K. In pseudo-first-order conditions the rate constant (kobs) decreased regularly with increasing [TX-100]. To understand the self-organizing activities of TX-100, CMC values in varying reaction conditions had been evaluated. The role of non-ionic surfactant in the oxidative degradation process of ciprofloxacin by chlorinating agent chloramine-T is explained in terms of mathematical model explained by Menger-Portnoy. The reaction showed first to zero order dependence on [CAT] and fractional order on [CIP]. Increasing [H+] decreased the rate of reaction. The effect of ionic strength and solvent polarity of the medium in reaction conditions were studied. The effects of added salts [HSO4Na], [KCl], [KNO3] and [K2SO4] had also been studied. The stoichiometry of the reaction determined was 1:2 and the oxidation products were identified by LC-EI-MS. The analysis of degradation product of ciprofloxacin evidently reveals that the piperazine moiety is active site for oxidation in the reaction. Activation parameters were studied to propose appropriate mechanism for the reaction.

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Kinetics of metribuzin degradation by colloidal manganese dioxide in absence and presence of surfactants

Chemical Papers ◽

10.2478/s11696-013-0424-7 ◽

2014 ◽

Vol 68 (1) ◽

Cited By ~ 17

Author(s):

Qamruzzaman ◽

Abu Nasar

Keyword(s):

Sodium Dodecyl ◽

Oxidative Degradation ◽

Activation Parameters ◽

Water Soluble ◽

Ionic Surfactant ◽

Ammonium Bromide ◽

Pseudo First Order Reaction ◽

First Order ◽

Colloidal Mno2 ◽

Kinetics Of

AbstractThe kinetics of the degradation of metribuzin by water-soluble colloidal MnO2 in acidic medium (HClO4) were studied spectrophotometrically in the absence and presence of surfactants. The experiments were performed under pseudo-first-order reaction conditions in respect of MnO2. The degradation was observed to be of the first order in respect of MnO2 while of fractional order for both metribuzin and HClO4. The rate constant for the degradation of metribuzin was observed to decrease as the concentration of MnO2 increased. The anionic surfactant, sodium dodecyl sulphate (SDS), was observed to be ineffective whereas the non-ionic surfactant, Triton X-100 (TX-100), accelerated the reaction rate. However, the cationic surfactant, cetyltrimethyl ammonium bromide (CTAB), caused flocculation with oppositely-charged colloidal MnO2; hence further study was not possible. The catalytic effect of TX-100 was discussed in the light of the available mathematical model. The kinetic data were exploited to generate the various activation parameters for the oxidative degradation of metribuzin by colloidal MnO2 in the absence as well as the presence of the non-ionic surfactant, TX-100.

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Kinetics and Mechanism of Oxidation of Alizarin Yellow R Dye by Chloramine-T in Hydrochloric Acid Medium. A Spectrophotmetric Study

International Journal of Science and Engineering Invention ◽

10.23958/ijsei/vol04-i10/108 ◽

2018 ◽

Vol 4 (10) ◽

Author(s):

Fathyah Omar Abdulsalam ◽

Dr. Asha Iyengar T.

Keyword(s):

Hydrochloric Acid ◽

Activation Parameters ◽

Oxidation Products ◽

First Order ◽

Alizarin Yellow ◽

Hydrochloric Acid Medium ◽

Alizarin Yellow R ◽

Chloramine T ◽

Kinetics Of ◽

Hcl Medium

Kinetics of oxidative decolorization of alizarin yellow R (AYR) by chloramine-T (CAT) in hydrochloric acid (HCl) medium at 304 K has been investigated spectrophotometrically at Î»max520 nm. The reaction showed first-order rate dependence on [CAT] and [AYR]o and fractional order dependence on [HCl]. Stoichiometry of the reaction was found to be 1:1 with respect to the substrate and oxidant respectively. The oxidation products were identified by spectral analysis. Variation of ionic strength had no effect on the rate. Addition of p-toluene sulphonamide (PTS) did not retard the rate of the reaction. Activation parameters have been computed. Probable mechanism and the relevant rate law have been deduced for the observed kinetic results.

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Characterization and thermal degradation kinetics of thermoplastic polyimide based on BAPP

High Performance Polymers ◽

10.1177/0954008317729741 ◽

2017 ◽

Vol 30 (7) ◽

pp. 787-793 ◽

Cited By ~ 4

Author(s):

Xu Su ◽

Yong Xu ◽

Linshuang Li ◽

Chaoran Song

Keyword(s):

Thermogravimetric Analysis ◽

Thermal Degradation ◽

Degradation Kinetics ◽

Degradation Process ◽

Thermal Degradation Kinetics ◽

Heating Rates ◽

Step Method ◽

Nitrogen Derivative ◽

Degradation Reaction ◽

Kinetics Of

Two kinds of thermoplastic polyimides (PIs) were synthesized via a two-step method with 2,2-bis[4-(4-aminophenoxy)phenyl]propane (BAPP), 4,4′-oxydianiline (ODA) diamine, and 3,3′,4,4′-benzophenonetetracarboxylic dianhydride (BTDA), and their thermal degradation kinetics was studied by thermogravimetric analysis at different heating rates under nitrogen. Derivative thermogravimetric analysis curves indicated a simple, single-stage degradation process in PI BTDA-BAPP and a two-stage degradation process in PI BTDA-ODA-BAPP. The activation energies ( Eas) of the thermal degradation reaction were determined by the Flynn–Wall–Ozawa and Kissinger–Akahira–Sunose methods without a knowledge of the kinetic reaction mechanism. By comparing the values of Ea and weight loss temperatures, it was demonstrated that the thermal stability of PI BTDA-ODA-BAPP was superior to that of PI BTDA-BAPP.

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Thermo-Oxidative Degradation Kinetics of Biomass Pseudo-Components Using Asymmetric Function of Bi-Gaussian as Deconvolution Technique

SSRN Electronic Journal ◽

10.2139/ssrn.3966931 ◽

2021 ◽

Author(s):

Weizhen Li ◽

Yanqin Huang ◽

Huacai Liu ◽

Yang Jiang ◽

Yan Wang ◽

...

Keyword(s):

Degradation Kinetics ◽

Oxidative Degradation ◽

Deconvolution Technique ◽

Kinetics Of ◽

Asymmetric Function ◽

Thermo Oxidative Degradation

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Isolation and Structure Determination of Echinochrome A Oxidative Degradation Products

Molecules ◽

10.3390/molecules25204778 ◽

2020 ◽

Vol 25 (20) ◽

pp. 4778

Author(s):

Natalia P. Mishchenko ◽

Elena A. Vasileva ◽

Andrey V. Gerasimenko ◽

Valeriya P. Grigorchuk ◽

Pavel S. Dmitrenok ◽

...

Keyword(s):

Mass Spectrometry ◽

Degradation Products ◽

Lethal Dose ◽

Oxidative Degradation ◽

Degradation Process ◽

Oxidation Products ◽

Chemical Mechanism ◽

Ionization Mass ◽

Echinochrome A ◽

Esi Ms

Echinochrome A (Ech A, 1) is one of the main pigments of several sea urchin species and is registered in the Russian pharmacopeia as an active drug substance (Histochrome®), used in the fields of cardiology and ophthalmology. In this study, Ech A degradation products formed during oxidation by O2 in air-equilibrated aqueous solutions were identified, isolated, and structurally characterized. An HPLC method coupled with diode-array detection (DAD) and mass spectrometry (MS) was developed and validated to monitor the Ech A degradation process and identify the appearing compounds. Five primary oxidation products were detected and their structures were proposed on the basis of high-resolution electrospray ionization mass spectrometry (HR-ESI-MS) as 7-ethyl-2,2,3,3,5,7,8-heptahydroxy-2,3-dihydro-1,4-naphthoquinone (2), 6-ethyl-5,7,8-trihydroxy-1,2,3,4-tetrahydronaphthalene-1,2,3,4-tetraone (3), 2,3-epoxy-7-ethyl-2,3-dihydro-2,3,5,6,8-pentahydroxy-1,4-naphthoquinone (4), 2,3,4,5,7-pentahydroxy-6-ethylinden-1-one (5), and 2,2,4,5,7-pentahydroxy-6-ethylindane-1,3-dione (6). Three novel oxidation products were isolated, and NMR and HR-ESI-MS methods were used to establish their structures as 4-ethyl-3,5,6-trihydroxy-2-oxalobenzoic acid (7), 4-ethyl-2-formyl-3,5,6-trihydroxybenzoic acid (8), and 4-ethyl-2,3,5-trihydroxybenzoic acid (9). The known compound 3-ethyl-2,5-dihydroxy-1,4-benzoquinone (10) was isolated along with products 7–9. Compound 7 turned out to be unstable; its anhydro derivative 11 was obtained in two crystal forms, the structure of which was elucidated using X-ray crystallography as 7-ethyl-5,6-dihydroxy-2,3-dioxo-2,3-dihydrobenzofuran-4-carboxylic acid and named echinolactone. The chemical mechanism of Ech A oxidative degradation is proposed. The in silico toxicity of Ech A and its degradation products 2 and 7–10 were predicted using the ProTox-II webserver. The predicted median lethal dose (LD50) value for product 2 was 221 mg/kg, and, for products 7–10, it appeared to be much lower (≥2000 mg/kg). For Ech A, the predicted toxicity and mutagenicity differed from our experimental data.

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Oxidative degradation kinetics of lycopene, lutein, and 9-cis and all-trans β-carotene

Journal of the American Oil Chemists Society ◽

10.1007/s11746-998-0232-3 ◽

1998 ◽

Vol 75 (7) ◽

pp. 823-829 ◽

Cited By ~ 146

Author(s):

L. K. Henry ◽

G. L. Catignani ◽

S. J. Schwartz

Keyword(s):

Degradation Kinetics ◽

Oxidative Degradation ◽

Kinetics Of ◽

Β Carotene

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Kinetics and mechanistic study of the ruthenium(III) catalyzed oxidative deamination and decarboxylation of L-valine by alkaline permanganate

Canadian Journal of Chemistry ◽

10.1139/v01-173 ◽

2001 ◽

Vol 79 (12) ◽

pp. 1926-1933 ◽

Cited By ~ 12

Author(s):

Dinesh C Bilehal ◽

Raviraj M Kulkarni ◽

Sharanappa T Nandibewoor

Keyword(s):

Ionic Strength ◽

Alkaline Medium ◽

Activation Parameters ◽

Solvent Polarity ◽

Mechanistic Study ◽

Reaction Products ◽

Order Dependence ◽

Alkaline Permanganate ◽

Kinetics Of ◽

Catalyzed Oxidation

The kinetics of ruthenium(III) catalyzed oxidation of L-valine by permanganate in alkaline medium at a constant ionic strength has been studied spectrophotometrically. The reaction between permanganate and L-valine in alkaline medium exhibits 2:1 stoichiometry (KMnO4:L-valine). The reaction shows first-order dependence on the concentration of permanganate and ruthenium(III) and less than unit-order dependence on the concentrations of L-valine and alkali. The reaction rate increases both with an increase in ionic strength and a decrease in solvent polarity of the medium. Initial addition of reaction products did not significantly affect the rate. A mechanism involving the formation of a complex between catalyst and substrate has been proposed. The activation parameters were computed with respect to the slowest step of the mechanism.Key words: oxidation, L-valine, catalysis, ruthenium(III), kinetics.

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