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

• Published in: Analytical letters 2005-01, Vol.38 (10), p.1601-1610
• Main Authors: Farias, Percio A. M., Wagener, Angela de Luca Rebello, Aguiar Castro, Arnaldo, Bastos, Margarida Bethlem R.
• Format: Article
• Language: English
• Subjects: Acridine orange determination; adsorptive accumulation; Analytical chemistry; Chemistry; EDTA; Electrochemical methods; Exact sciences and technology; ssDNA; stripping voltammetry
• ISSN: 0003-2719; 1532-236X
• DOI: 10.1081/AL-200065796

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 .