Kinetic and equilibrium analysis of peracetic acid formation at 1753 cm1 mid-infrared absorption peak using facile attenuated total reflection Fourier transform infrared technique

• Main Authors: Fu, Cheng-Hsin, Chen, Guan-Yu, Lin, Yueh-Hsin, Lin, Cheng-Huan, Muthiah, Balaganesh, Kasai, Toshio, Morita, Kinichi, Mito, Hiroyuki, Espulgar, Wilfred V., Santos, Gil Nonato C., Yu, Derrick Ethelbehrt C.
• Format: text
• Published: Animo Repository 2023
• Subjects: Organic acids; Attenuation (Physics); Fourier transform infrared spectroscopy; Chemistry; Physics
• Online Access: https://animorepository.dlsu.edu.ph/faculty_research/11480
• Institution: De La Salle University

Introduction: Peracetic acid (PAA) is a highly effective disinfectant against a wide range of viruses and bacteria. Its versatility, cost‐effectiveness, and ability to quickly decontaminate large areas make it an ideal choice. PAA is also envi- ronmentally friendly and safe, as it does not produce any harmful by‐products. However, to ensure its efficacy, it is crucial to maintain the optimal concentra- tion of PAA in the solution. Objective: The objective of the study is to investigate the use of attenuated total reflection Fourier transform infrared (ATR‐FTIR) spectroscopy as a method for quantifying the concentration of peracetic acid (PAA), which comes in quater- nary equilibrium mixture in commercial formulation. The study also aims to determine the rate constants and equilibrium constant for the production of PAA in various conditions, including the presence of catalyst and stabilizer. Methods: The spectra of all chemicals in PAA solution obtained in FT‐IR Spec- trometer were compared to identify the characteristic peaks of PAA, which were then computed using normal mode analysis at B3LYP/6‐31G(d) level by Gauss- ian 09. The ATR‐FTIR was used to measure time‐dependent PAA signals until they reached equilibrium in three different conditions: (1) Acetic acid (10 to 17.4 M) and hydrogen peroxide (5 M), (2) with sulfuric acid as catalyst, and (3) with phosphoric acid as stabilizer. The collected data was analyzed through regression analysis, in which curves and rate law formulas were fitted to obtain the rate constants for peracetic acid synthesis and hydrolysis. Results: This study shows that ATR‐FTIR spectroscopy can detect and quan- tify peracetic acid with a characteristic peak at 1753 cm−1. The proposed method is applicable to all peracetic acid solutions, including those with stabi- lizers and catalysts. The ATR‐FTIR method offers advantages such as short detection time, simple operation, small sampling volume, and accurate mea- surement. Moreover, the accuracy of this quantitative method is confirmed by the fact that the reaction rate constants deduced from the fitted curves are more consistent with the actual reaction rate constants than those of the refer- ence data based on KI titration method.