Influence of Potential Antioxidant Agents on Titration of Hydrogen Peroxide

Objectives: To determine the concentration of hydrogen peroxide (HP) - used for in-office bleaching - under the influence of some substances considered as antioxidants.
Methods: Concentration (%) of HP was quantified (in triplicate) by permanganometry, according to USP method, after mixed with 1% ascorbic acid solution (AAcid), 1% sodium ascorbate solution (SodAs), 1% ethanol solution of alpha-tocopherol (α-Toc), 1% sodium fluoride solution (NaF) and 1% potassium nitrate solution (KNO₃). The mean value of each substance was analyzed by one-way ANOVA and Tukey’s test (p = 0.05).
Results: HP presented similar lowest values when mixed with AAcid, SodAs and α-Toc (26.93%, 27.67% and 27.87%, respectively; p > 0.05). When mixed with KNO₃ the obtained value (33.73%) was higher (p < 0.05). The highest values (p < 0.05) were observed when mixed with NaF (36.76%).
Conclusions: Considering the results of this experiment, potassium nitrate (KNO₃) and sodium fluoride (NaF) cannot be considered as antioxidants.