Fluorescence detection of carbon-centered radicals in aqueous solution.
A simple, highly sensitive method for the simultaneous determination of arrays of carbon-centered radicals in aqueous systems is described. Radicals are efficiently trapped by an amino-nitroxide to form stable products which are then reacted with fluorescamine to produce highly fluorescent adducts. The adducts are easily separated by reversed-phase high performance liquid chromatography. The detection limit for individual radical adducts (0.5 to 2 nM) is two to three orders of magnitude lower than those of current methods employing electron paramagnetic resonance detection. Results on the photolysis of ketones and alpha-keto acids demonstrate the potential of this technique. This approach should be widely applicable to the study of radical processes in biological and chemical systems.
Kieber
D J
DJ
Woods Hole Oceanographic Institution, Chemistry Department, Woods Hole, Massachusetts 02543.
Blough
N V
NV
D055598:Chemical Phenomena; D002621:Chemistry; D002851:Chromatography, High Pressure Liquid; D004578:Electron Spin Resonance Spectroscopy; D005609:Free Radicals; D007651:Keto Acids / Q000032:analysis; D007659:Ketones / Q000032:analysis; D009603:Nitroso Compounds / Q000032:analysis; D010777:Photochemistry; D012996:Solutions; D013050:Spectrometry, Fluorescence; D013113:Spin Labels
D005609:Free Radicals; D007651:Keto Acids; D007659:Ketones; D009603:Nitroso Compounds; D012996:Solutions; D013113:Spin Labels