Adsorptive Stripping Voltammetric Behavior of Acridine Orange at the Static Mercury Drop Electrode

Abstract

The electrochemical behavior of acridine orange was investigated as to allow the development of a stripping method for the determination of acridine orange at the sub‐micromolar concentration level. The optimized reaction is based on controlled adsorptive accumulation of acridine orange at the static mercury drop electrode followed by differential pulse measurement of the surface species. The adsorptive stripping response is evaluated with respect to the concentration dependence, the preconcentration time and potential, the presence of reacting ions, EDTA, ssDNA and other variables. Best results were obtained using 1.0×10⁻³ mol L⁻¹ sodium hydroxide solution as the supporting electrolyte. Compared to the response of solution‐phase voltammetry, a signal enhancement factor of about 7 is observed when using 90 s preconcentration. The standard deviation at the 2.5×10⁻⁶ mol L⁻¹ level (0.284 µA) is ±0.019 µA and the detection limit equals 1.0×10⁻⁸ mol L⁻¹.

Keywords:

• Acridine orange determination
• stripping voltammetry
• adsorptive accumulation
• EDTA
• ssDNA

The authors gratefully acknowledge the CNPq and CAPES of the Government of Brazil and PUC‐Rio for support of this work. The experimental assistance of A.B. Neves is appreciated.

Additional information

Notes on contributors

Arnaldo Aguiar Castro

Permanent address: Arnaldo Aguiar Castro, Fac. Quimica, Quimica Analitica, Universidad de La Habana, Cuba.