Abstract
A novel fluorimetric method for the determination of peroxynitrite (ONOO-) using hemoglobin (Hb) as a catalyst is described. The method employs the reaction of ONOO- with thiamine (TM), a colorless, non-fluorescent reagent in a glycine-NaCl-NaOH buffer solution (pH 12.7), to generate a highly fluorescent product, thiochrome (TC). The fluorescent product was monitored by fluorimetry. A linear calibration graph was obtained over an ONOO- concentration range from 4.95 × 10-7 mol L-1 to 2.97 × 10-5 mol L-1, with a detection limit of 9.78 × 10-9 mol L-1 ONOO-. The relative standard deviation at an ONOO- concentration of 2.11 × 10-6 mol L-1 was 4.15% (n = 9).
