Adsorptive Stripping Voltammetric Determination Of Cobalt (Ii) On The Carbon Paste Electrode

Traces of cobalt (II) can be determined by adsorptive stripping voltammetry using Nitroso-S as complex forming reagent. First in acetate buffer pH 5.0, cobalt (II)-Nitroso-S complex was adsorbed on the carbon paste electrode with an accumulation potential of +0.1 V. Following this, adsorbed complex was detected by cathodic differential pulse voltammetric scan from +0.1 to -0.6 V. The effective parameters in sensor response were examined. The detection limit of Co(II) was 1.8 mu g l(-1) and relative standard deviations for 10 and 100 mu g l(-1) of Co(II) were 0.8 and 1.2%, respectively. The calibration curve was linear for 3.3-187.1 mu g l(-1) Co(II). This technique does not use mercury and therefore, has a positive environmental benefit. The method, which is reasonably sensitive and selective, has been successfully applied to the determination of trace amount of Co(II) in water samples.