Photometric determination of peracetic acid by reaction with potassium iodide solution.

Abstract

Peracetic acid (PAA) is a strong oxidizing agent and is considered an ideal disinfectant because of its excellent disinfecting effect at low concentration, low corrosiveness, and relatively low cost. Commercially available PAA solution is a mixture of PAA, acetic acid, and hydrogen peroxide. However, PAA naturally decomposes faster than hydrogen peroxide. Therefore, accurately quantifying the concentration of PAA in the PAA peroxide mixture via a simple method is important. In the present study, a new method was developed, in which the spectral change of I- ion at 226nm and the absorption value from the generated I2 at 460nm were used to determine the concentration of PAA, following a chemical reaction with 0.1mM potassium iodide (KI) solution without the use of any other chemicals. In this work, the measurable concentration of PAA was as low as 0.0001 wt% (13.1µM) and as high as 0.0015 wt% (197.2µM), which matches well with high linearity (99.95% at 226nm and 99.91% at 460nm). This work could also be the high selectivity method toward PAA in the PAA peroxide mixture.