FACTORS INFLUENCING ANODIC STRIPPING VOLTAMMETRY SIGNALSOF As(III) AT Au-COATED BORON-DROPPED DIAMOND ELECTRODE

Abstract

The influence of the composition of the analyte solution and several major parameters of differential pulse anodic stripping voltammetry on the stripping peak current (I_p) of As(III) at gold film boron-doped diamond electrodes (fabricated by ex-situ combined with in-situ techniques) was investigated. The results showed that the analyte solution containing 0.7 M HCl, 0.3 mM ascorbic acid, and 2 mg/L Au (III) was suitable for the I_p measurement with a high intensity and good repeatability. Cleaning the electrode at +600 mV for 5 seconds after each measurement could increase the repeatability of I_p. Compared with electrodes prepared by means of ex-situ technique, electrodes fabricated by using ex-situ combined with in-situ techniques allowed to apply longer deposition time to quantify As(III) in low-concentration solutions.