Spectrophotometric Determination of Peroxynitrite Usingo‐Phenylenediamine as a Probe

In the present study, a novel spectrophotometric method for the determination of peroxynitrite using, o‐phenylenediamine as a probe is described. The method is based on the oxidation of o‐phenylenediamine, a colorless substance, by peroxynitrite to give a colored product. The absorbance increase of the reaction system is linearly related to the concentration of peroxynitrite in the range of 4.4 × 10−7–8.0 × 10−6 mol l−1 with a detection limit of 1.7 × 10−7 mol l−1 (3σ). The optimal conditions for the detection of peroxynitrite were evaluated and the possible detection mechanism was also discussed in this paper.