SUPEROXIDE ION CHEMISTRY. REACTION OF SUPEROXIDE ION WITH 2,4,6-TRISUBSTITUTED PYRYLIUM TETRAFLUOROBORATES

The rate of reaction of superoxide radical ion with oxyhaemoglobin and methaemoglobin.

Superoxide radical ions (O2-) produced by the radiolytic reduction of oxygenated formate solutions and by the xanthine oxidase-catalysed oxidation of xanthine were shown to oxidize the haem groups in oxyhaemoglobin and reduce those in methaemoglobin as in reactions (1) and (2): (see articles) Reaction (1) is suppressed by reaction (8) when [O2-]exceeds 10 muM, but consumes all the O2- generated...

Advancing proteomics with ion/ion chemistry.

Mass spectrometers, instruments that use electric and/or magnetic fields to measure a gas-phase ion's mass-to-charge ratio (m/z), are used in a wide variety of applications--with the field having a reputation for providing good sensitivity and high-informing power. Protein analysis (proteomics) is a relatively recent affair for the field and was enabled in the late 1980s with the advent of biom...

Droplet Phase Ion-Ion Chemistry

Photochemical degradation of azure-b with sulphate radical ion generated by peroxydisulphate ion with cupric ion

In this paper, the photochemical degradation of azure-b by Cu2+/S2O82− process has beenpresented. Cu2+ as photocatalyst and S2O82− ion as photooxidant used in this process. Atextremely low concentrations, cupric ion showed true catalytic activity in the overall process.The influence of various parameters on the performance of the treatment process has beenconsidered, such as pH, concentration o...

Superoxide ion as active intermediate in the autoxidation of ascorbate by molecular oxygen. Effect of superoxide dismutase.

The oxidation of ascorbic acid by molecular oxygen was investigated by optical and magnetic resonance methods in the presence and in the absence of copper and iron complexes. The results show that one superoxide ion is generated for each oxidized molecule of ascorbate. The effect of addition of Cu,Zn superoxide dismutase, which at concentrations higher than 10(-7) M halves the oxidation rate, i...