DEVELOPMENT OF IN SITU BISMUTH FILM ELECTRODE FOR DIFFERENTIAL PULSE ANODIC STRIPPING VOLTAMMETRIC DETERMINATION OF TRACE COPPER IN WATER
Abstract
: Bismuth film electrode prepared in situ on glassy carbon disk surface (abbreviated to BiFE in situ) was used as working electrode for Differential Pulse Anodic Stripping Voltammetry (DP-ASV) for the determination of copper (Cu) in acetate buffer (pH = 5). The influence of the factors on Cu stripping peak curents (Ip) such as: BiIII concentration, pH, deposition potential and deposition time, the electrode rotating speed, interferents,… were investigated. At the deposition potential of -1400 mV, the deposition time of 120 s and other appropriate experimental conditions, the method gained high sensitivity (0.35 ± 0.01 μA/ppb), good repeability of the Ip : RSD = 2.8 % (n = 8), low detection limit (3s) was (1.4 ppb); linear correlation between the Ip and the Cu concentration was good in the range of 2.5 – 25 ppb (R ≥ 0.998). This method was successfully applied to the determination of Cu in river-water samples at Quang Binh province.