Simultaneous spectra-kinetic determination of peracetic acid and hydrogen peroxide in a brewery cleaning-in-place disinfection process

A spectra-kinetic approach was applied for the simultaneous determination of peroxyacetic acid (PAA) and hydrogen peroxide with multiple linear regression (MLR) method, using the initial rates of their reaction with diphenylamine (DPA). The predictive ability of the MLR method is based on the slight kinetic differences of these analytes occur at two wavelengths when react with DPA as a common ligand. A stopped flow apparatus was used, and the time-resolved UV–vis spectra were measured with a coupled charge device (CCD) spectrophotometer. This novel instrumentation allowed to obtain high quality kinetic data at a maximum of many wavelengths simultaneously. The method was successfully applied to the simultaneous determination of these peroxides in residues from a disinfection process in a beer brewery.