Anodic stripping voltammetry: Arsenic determination in ancient bone samples

A highly sensitive method for the determination of arsenic (As) content in ancient bone samples was studied using a gold tipped rotating disc electrode and differential pulse anodic stripping voltammetry. Factors affecting sensitivity and precision, including electrolyte concentration, deposition potential, deposition time, and rotation rate were investigated. Electroinactive As(V) was reduced to As(III) by HCl 30% w/v prior to electroanalytical measurements. For a deposition time of 120 sec, the lowest detection limit (LOD) for arsenic was 1.078 mu g/L. Optimized working conditions are defined as a deposition potential of -1200 mV with a deposition time of 120 sec, 10 M HCl as the supporting electrolyte, and a rotation rate of 2000 rpm. Results of electroanalytial measurements in ancient bone samples are compared with those obtained from the hydride generation atomic absorption spectroscopy (HG-FAAS) analysis. Analytical relevancy of the two methods was then compared with the aid of statistical data treatment.