Determination of peracetic acid in the presence of hydrogen peroxide based on the catalytic oxidation of ABTS

Determination of the concentration of peracetic acid (PAA) in the presence of H2O2 is a great challenging problem due to the similar chemical behaviors of the two species. In this study, we developed a new method for simultaneous measurement of PAA (0.5 – 10.0 μM) and total peroxides (i.e., PAA and H2O2 with a molar ratio of 10:6.5), based on the catalytic oxidation of ABTS by separately using Co(II) and peroxidase (POD) as the catalysts. Owing to the unique catalytic activity of Co(II) towards PAA, the coexistent H2O2 exhibits negligible effect on the determination of PAA. The value of absorbance at 415 nm increases linearly with increasing the concentration of PAA or total peroxides, and the sensitivities for PAA and total peroxides are as high as 5.31 × 104 and 9.07 × 104 M−1 cm−1, respectively. In addition, the proposed ABTS method shows excellent feasibility and applicability, which make it suitable to be employed for detection in complicated water matrices.