Analytical Sciences

Abstract − Analytical Sciences, 21(4), 445 (2005).

Fluorimetric Determination of Peroxynitrite Based on an Enzymatic Reaction
Qi Hua CAO, Qian Xiong ZHOU, Ru Xiu CAI, and Zhi Hong LIU
Department of Chemistry, Wuhan University, Wuhan 430072, People’s Republic of China
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).