Flexible Potentiometric Minisensor Based on Manganese Dioxide‐Composite for the Determination of Hydrogen Peroxide in Bleach and Pharmaceutical Products

Abstract

A new flexible minisensor based on MnO₂/graphite/epoxy resin composite for the potentiometric determination of hydrogen peroxide was developed in this work. Under optimum experimental conditions, such as 25°C, 4 h of conditioning time in 0.1 mol L⁻¹ NH₃‐NH₄ ⁺ buffer solution (pH 8.5) and a composition of 10/60/30% w/w MnO₂/graphite/epoxy resin, respectively, the minisensor presented a Nernstian response for H₂O₂ in the concentration range from 6.0×10⁻⁷ to 1.0×10⁻³ mol L⁻¹, with a slope of −58.5±0.2 mV/pH₂O₂ with a detection limit of 1.6×10⁻⁸ mol L⁻¹ H₂O₂. The useful lifetime of the proposed minisensor was at least 6 months (over 670 determinations for each composite), the response time was smaller than 1.5 min, and it was successfully applied in the determination of hydrogen peroxide in bleach and pharmaceutical products.

Keywords:

• Hydrogen peroxide
• manganese dioxide
• potentiometric
• flexible minisensor

Acknowledgments

The authors acknowledge financial support from FAPESP, CAPES, and CNPq and scholarship granted by CNPq to R.L.R.P.F.

Additional information

Notes on contributors

Karina Omuro Lupetti

Karina Omuro Lupetti's present address is Instituto de Química, Universidade de São Paulo, P. O. Box 780, 13560-970, São Carlos-SP, Brazil