THE Co60 γ-RADIOLYSIS OF AQUEOUS CYSTINE SOLUTIONS: I. THE EFFECT OF CHLORIDE ION ON THE AMMONIA YIELD

1963 ◽  
Vol 41 (8) ◽  
pp. 1882-1887 ◽  
Author(s):  
W. A. Armstrong ◽  
D. W. Grant
Keyword(s):  
Amino Acid ◽  
Sodium Chloride ◽  
Hydroxyl Radicals ◽  
Rate Constants ◽  
Chloride Ion ◽  
Chlorine Atoms

Sodium chloride has been found to increase the ammonia yield from Co60γ-irradiated cystine in 0.02 M H2SO4. The effect is attributed to the participation of chlorine atoms, which deaminate the amino acid to a greater extent than hydroxyl radicals. The ratio of the rate constants [Formula: see text] is determined to be 24 in 0.02 M H2SO4.

ChemInform Abstract: Rate Constants for the Reactions of Hydroxyl Radicals and Chlorine Atoms with Halogenated Aldehydes.

ChemInform ◽  
2010 ◽  
Vol 24 (35) ◽  
pp. no-no
Author(s):  
D. J. SCOLLARD ◽  
J. J. TREACY ◽  
H. W. SIDEBOTTOM ◽  
C. BALESTRA-GARCIA ◽  
G. LAVERDET ◽  
...  
Keyword(s):  
Hydroxyl Radicals ◽  
Rate Constants ◽  
Chlorine Atoms

Rate constants for the reactions of hydroxyl radicals and chlorine atoms with halogenated aldehydes

1993 ◽  
Vol 97 (18) ◽  
pp. 4683-4688 ◽  
Author(s):  
D. J. Scollard ◽  
J. J. Treacy ◽  
H. W. Sidebottom ◽  
C. Balestra-Garcia ◽  
G. Laverdet ◽  
...  
Keyword(s):  
Hydroxyl Radicals ◽  
Rate Constants ◽  
Chlorine Atoms

Relative rate constants for reactions of hydroxyl radicals from the reaction of Fe(II) or Ti(III) with H2O2

1969 ◽  
Vol 47 (20) ◽  
pp. 3737-3744 ◽  
Author(s):  
W. A. Armstrong
Keyword(s):  
Hydrogen Peroxide ◽  
Hydroxyl Radicals ◽  
Rate Constants ◽  
Relative Rate ◽  
Chloride Ion ◽  
Strong Electron ◽  
Spin Resonance ◽  
Relative Rate Constants ◽  
Novel Method ◽  
Hydroxyl Radical Scavengers

In an attempt to clarify the reactions of ferrous sulfate and titanous sulfate with hydrogen peroxide, a novel method has been developed to determine the relative rate constants for reactions of the oxidizing species generated in these systems. These species react with hydrogen peroxide to give perhydroxyl radicals which combine with titanium(IV) ions to form the relatively stable TiOO•3+ radical. This radical gives a strong electron spin resonance signal and the competition between hydrogen peroxide and a scavenger for the oxidizing species can be followed by measuring the amplitude of this signal in the presence of various concentrations of scavenger. The relative rate constants calculated in this way for both the Fe(II)–H2O2 and Ti(III)–H2O2 systems at pH 1.0 agree with those reported for the reactions of hydroxyl radicals in γ-irradiated thymine solutions. This supports the view that hydroxyl radicals are formed in these cases.Under conditions of acidity favoring the hydrolysis of Fe(II) to FeOH+ ions, hydroxyl radical scavengers do not compete with hydrogen peroxide for the precursors of the TiOO•3+ radical. It is suggested that the FeOH+ ions react with hydrogen peroxide to give a different oxidizing species, possibly the ferryl ion.Scavengers investigated were thymine, methanol, ethanol, formic acid, acetic acid, chloride ion, and several amino acids.

scholarly journals Stability of Glycine in Saline Solutions Exposed to Ionizing Radiation

2020 ◽  
Vol 7 (2) ◽  
pp. 83-87
Author(s):  
Laura Patricia Cruz-Cruz ◽  
Alicia Negrón-Mendoza ◽  
Alejandro Heredia-Barbero
Keyword(s):  
Amino Acid ◽  
Sodium Chloride ◽  
Ionizing Radiation ◽  
Chloride Ion ◽  
External Source ◽  
Protective Role ◽  
Primitive Earth ◽  
The Stability ◽  
Bodies Of Water ◽  
Saline Solutions

The stability of biologically important molecules, such as amino acids, being subjected to highradiation fields is relevant for chemical evolution studies. Bodies of water were very important in the primitive Earth. In these bodies, the presence of dissolved salts, together with organic molecules, could influence the behavior of the systems in prebiotic environments.The objective of this work is to examine the influence of sodium chloride on the stability of the amino acid glycine when subjected to high radiation doses. The analysis of the irradiated samples was followed by HPLC coupled with a UV-VIS detector. The results show that glycine in aqueous solutions (without oxygen) decomposed around 90% at a dose of 91 kGy. In the presence of salts, up to 80% of the amino acid was recovered at the same dose. Laboratory simulations demonstrate a protective role for sodium chloride (specifically the chloride ion) to glycine against an external source of ionizing radiation.

Salt effect in hydrolysis of 3-acyl-1,3-diphenyltriazenes

1981 ◽  
Vol 46 (12) ◽  
pp. 3104-3109 ◽  
Author(s):  
Miroslav Ludwig ◽  
Oldřich Pytela ◽  
Miroslav Večeřa
Keyword(s):  
Sodium Chloride ◽  
Temperature Dependence ◽  
Potassium Chloride ◽  
Rate Constants ◽  
Zinc Sulphate ◽  
Salt Effect ◽  
Sodium Sulphate ◽  
Potassium Sulphate ◽  
Lithium Sulphate ◽  
Hydrolysis Of

Rate constants of non-catalyzed hydrolysis of 3-acetyl-1,3-diphenyltriazene (I) and 3-(N-methylcarbamoyl)-1,3-diphenyltriazene (II) have been measured in the presence of salts (ammonium chloride, potassium chloride, lithium chloride, sodium chloride and bromide, ammonium sulphate, potassium sulphate, lithium sulphate, sodium sulphate and zinc sulphate) within broad concentration ranges. Temperature dependence of the hydrolysis of the substrates studied has been measured in the presence of lithium sulphate within temperature range 20° to 55 °C. The results obtained have been interpreted by mechanisms of hydrolysis of the studied substances.

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