Free radical yields from the homolysis of peroxynitrous acid.
A recent study reports discordant results for maximal free-radical yields from the decomposition of peroxynitrous acid using different assay reagents and a puzzling decrease (to zero) of the radical yields with increasing pH. An assay method using 2,2,'azino-bis(3-ethyl-benzthiazoline sulphonate) (ABTS) has been tested using stopped-flow kinetic studies, and the results imply that the assay is satisfactory when [HOONO] much greater than [-OONO] but that reactions involving peroxynitrite anion interfere at higher pH. Evidence is presented that peroxynitrite was an interfering species in the earlier studies.
Yang
G
G
Department of Chemistry, University of Newcastle upon Tyne, U.K.
Candy
T E
TE
Boaro
M
M
Wilkin
H E
HE
Jones
P
P
Nazhat
N B
NB
Saadalla-Nazhat
R A
RA
Blake
D R
DR
D052160:Benzothiazoles; D005609:Free Radicals; D006863:Hydrogen-Ion Concentration; D007202:Indicators and Reagents; D007700:Kinetics; D009566:Nitrates / Q000737:chemistry*; D009569:Nitric Oxide / Q000737:chemistry; D013451:Sulfonic Acids; D013481:Superoxides / Q000737:chemistry
D052160:Benzothiazoles; D005609:Free Radicals; D007202:Indicators and Reagents; D009566:Nitrates; D013451:Sulfonic Acids; D013481:Superoxides; C039642:peroxynitric acid; C002502:2,2'-azino-di-(3-ethylbenzothiazoline)-6-sulfonic acid; D009569:Nitric Oxide