Oxidation mechanism of carcinogenic bis-azo dyestuff Trypan Blue

1982 ◽  
Vol 47 (10) ◽  
pp. 2746-2748 ◽  
Author(s):  
Miroslav Matrka ◽  
Jana Pípalová
Keyword(s):  
Acid Medium ◽  
Quantitative Evaluation ◽  
Oxidation Product ◽  
Trypan Blue ◽  
Oxidation Mechanism ◽  
Azo Coupling ◽  
Arenediazonium Salt

Oxidation of Trypan Blue with cerium(IV) ion in acid medium gives arenediazonium cation similar to the oxidation product of N,N-dimethyl-4-aminoazobenzene. Quantitative evaluation of the arenediazonium salt formed has been carried out spectrophotometrically after previous C-azo coupling with 2-naphthol.

scholarly journals OS PERIGOS POR TRÁS DOS PRODUTOS QUÍMICOS DESTINADOS À ESTÉTICA CAPILAR: ANÁLISE DE FORMALDEÍDO

2018 ◽  
Vol 10 (Especial) ◽  
pp. 48-53
Author(s):  
Daniel Ângelo Macena ◽  
Weller Jean Bérgamo ◽  
Patrícia Alexandra Antunes
Keyword(s):  
Acid Medium ◽  
Quantitative Evaluation ◽  
Commercial Product ◽  
Smoothing Techniques ◽  
After Effects ◽  
Visible Spectrophotometry ◽  
Three Samples

– In order to achieve a better result in capillary smoothing techniques, the addition of Formaldehyde in the composition of the commercial product increases the risks of intoxication and cancer in the user. The objective of the study was to quali-quantitatively evaluate the concentration of formaldehyde in capillary straighteners. Acid medium and Schiff's reagent were used for identification and quantitative evaluation of visible spectrophotometry and questionnaire application to clients. Three samples were out of the standards that Anvisa establishes, because it is not allowed to use above 0.2% of formaldehyde in the product, in the analysis of the questions it was noticed that 50% of the interviewed women use this type of treatment, even knowing of the symptoms, risks and after effects not desirable and spend from R$ 100 to R$ 150 a month in the salon. We conclude that the use of formaldehyde is still a common practice, even with so many hazards and be prohibited by what establishes Anvisa.

scholarly journals Oxidation of Cinacalcet Hydrochloride by Chloramine-B in Acid Medium: A Kinetic and Mechanistic Study

2021 ◽  
Vol 33 (9) ◽  
pp. 2065-2068
Author(s):  
Nichhapurada Kallesha ◽  
Ningegowda Prasad ◽  
N. Shivakumara ◽  
Kereyagalahally H. Narasimhamurthy
Keyword(s):  
Thermodynamic Parameters ◽  
Acid Medium ◽  
Oxidation Product ◽  
Mechanistic Study ◽  
Spectroscopic Methods ◽  
Arrhenius Plots ◽  
Rate Law ◽  
Different Temperatures ◽  
Cinacalcet Hydrochloride ◽  
Hcl Medium

Kinetic and mechanistic study of cinacalcet hydrochloride by chloramine-B (CAB) in HCl medium at 308 K was the aim of this work. Analyzed the reaction at five different temperatures and determined the thermodynamic parameters using Arrhenius plots. The reaction had a stoichiometry of 1:2 and characterized the oxidation product using chromatographic and spectroscopic methods. The rate law is deduced from the marked effects, which were accompanied by plausible mechanisms.

scholarly journals A new method for the macro- and microdetermination of tri- and tetrathionate

1977 ◽  
Vol 55 (22) ◽  
pp. 3887-3893
Author(s):  
K. A. Idriss ◽  
I. M. Issa ◽  
M. R. Mahmoud
Keyword(s):  
Acid Medium ◽  
Sulphuric Acid ◽  
Oxidation Product ◽  
New Method ◽  
Optimum Conditions ◽  
Precise Method ◽  
End Point Detection ◽  
Point Detection ◽  
Sulphuric Acid Medium

A rapid and precise method is described for the determination of tri- and tetrathionate. It is based on oxidation of S3O62− or S4O62− with KMnO4 in sulphuric acid medium in the presence of fluoride, required for preventing the formation of insoluble oxides of manganese. The optimum conditions for both the visual and potentiometric end-point detection are 0.1–0.16 M H2SO4 and 0.24–0.38 M NaF. Trithionate is oxidized to sulphate as an end product, whereas the oxidation product of tetrathionate comprises dithionate and sulphate according to[Formula: see text]Examination of the potentiometric titrations and the spectrophotometric scans of samples being titrated showed the presence of intermediate equilibria in solution. The species produced are identified and a theory is given for the net reactions. The method is thoroughly dependable for the determination of amounts of S3O62− or S4O62− corresponding to 0.1–10 mg of sulphur.

A chronoamperometric study of the oxidative nucleation of niazid and isoniazid on mercury electrodes in basic solutions

2011 ◽  
Vol 76 (6) ◽  
pp. 755-762
Author(s):  
Mercedes Ruiz Montoya ◽  
Sara Pintado ◽  
José Miguel Rodríguez Mellado
Keyword(s):  
Electrode Surface ◽  
Oxidation Product ◽  
Oxidation Process ◽  
Mercury Electrode ◽  
Oxidation Mechanism ◽  
Electron Process ◽  
Basic Solutions ◽  
Mercury Electrodes

Using chronoamperometric measurements at pH 12 it is shown that the oxidation mechanism of niazid adsorbed on the mercury electrode changes with respect to the mechanism reported in the literature for the electrooxidation of the molecules reaching the electrode by diffusion. A compact monolayer of niazid molecules is formed on the electrode surface, being the hydrazide oxidized through a two-electron process. The oxidation product is not able to dissociate a H+ ion, and the oxidation process does not proceeds beyond. For isoniazid the monolayer never becomes compact.

Reactions of some 2-(6-azauracil-5-yl)phenylhydrazones

1979 ◽  
Vol 44 (8) ◽  
pp. 2438-2442 ◽  
Author(s):  
Jan Slouka
Keyword(s):  
Carboxylic Acid ◽  
Acid Medium ◽  
Alkaline Medium ◽  
Acidic Medium ◽  
Diazonium Salt ◽  
Azo Coupling

Azo coupling of the diazotized 6-(2-aminophenyl)-2,3,4,5-tetrahydro-1,2,4-triazine-3,5-dione with ethyl cyanoacetylcarbamate and diethyl malonyl-bis-carbamate has been used for preparation of the hydrazones I and II. The latter substances have been boiled in strongly acidic medium to give 2,3,4,6-tetrahydro-1,2,4-triazino[5,6-c]cinnoline-3-one (III) which has also been obtained by reduction of the mentioned diazonium salt with alkali sulphite and sebsequent cyclization of the formed hydrazine sulphonate by boiling in acid medium. In alkaline medium the hydrazones I and II have been cyclized to the nitrile IV and to 2-[2-(3,5-dioxo-2,3,4,5-tetrahydro-1,2,4-triazin-6-yl)-phenyl]-3,5-dioxo-2,3,4,5-tetrahydro-1,2,4-triazine-6-carboxylic acid (V), respectively.

Quantitative evaluation of -ray spectra from scintillation measurements

Physica ◽  
1952 ◽  
Vol 18 (2) ◽  
pp. 1147-1150
Author(s):  
D MAEDER ◽  
V WINTERSTEIGER
Keyword(s):  
Quantitative Evaluation
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