Selective peracetic acid determination in the presence of hydrogen peroxide using a label free enzymatic method based on catalase.
Peracetic acid (PAA) is selectively determined in the presence of hydrogen peroxide (H(2)O(2)) by using the self-indicating UV-Vis molecular absorption properties of catalase. The PAA reacts with the protein giving an intermediate (Cat-I) which is reduced back by the amino acid core surrounding the heme group. Since the original form of the enzyme and the Cat-I have different UV-Vis absorption properties, the absorbance changes can be used for PAA determination. The H(2)O(2)/catalase reaction is extremely fast so that neither Cat-I compound nor kinetic interferences are observed. The method permits PAA determination in the 5 × 10(-7) to 1.5 × 10(-5) M range, the reproducibility being between 1% and 10%. Using this method, PAA has been successfully determined in water samples treated with commercial PAA/H(2)O(2) biocides. A theoretical study has also been carried out for obtaining a mathematical model able to analytically describe the process.
Galbán
Javier
J
Analytical Chemistry Department, Analytical Biosensor Group (GBA), Faculty of Sciences, Aragón Institute of Nanoscience (INA), University of Zaragoza, 50006 Zaragoza, Spain. jgalban@unizar.es
Sanz
Vanesa
V
de Marcos
Susana
S
D002374:Catalase / Q000378:metabolism*; D002623:Chemistry Techniques, Analytical / Q000379:methods*; D006861:Hydrogen Peroxide / Q000737:chemistry*; D008962:Models, Theoretical; D010463:Peracetic Acid / Q000032:analysis*
D006861:Hydrogen Peroxide; D002374:Catalase; D010463:Peracetic Acid