Application of adsorptive cathodic stripping voltammetry for the determination of Cu, Cd, Ni and Co in atmospheric samples

Abstract

The application of adsorptive cathodic stripping voltammetry (ACSV) for the determination of Cu, Cd, Ni and Co in acid digested atmospheric samples was carried out. The accuracy of the technique was evaluated and compared with GFAAS (graphite furnace atomic absorption spectrometry) and ICP-MS (inductively coupled plasma mass spectrometry) using a standard reference material (MESS-1). All the considered techniques had the required accuracy. Detection limits were lowest for Cu and Ni using ACSV (0.30 and 0.08 ng ml −1 for a 10 × dilluted sample and a 1 min collection, respectively) whereas for Co detection limits were lowest by direct determination using ICP-MS analysis (0.03 ng ml −1). GFAAS had the lowest limit of detection for Cd (0.3 ng ml −1). Cd was not determined by ICP-MS in both MESS-1 and aerosol digests due to a higher detectionlimit. For all considered metals determined in low volume aerosol there were no statistical differences between all three techniques. In addition, there was no observable difference in the metal concentrations in the reference material during ACSV analysis of samples before and after UV irradation. However a significant difference was observed between ACSV analysis before and after UV irradation for Cu and Cd in aerosol acid digest samples but no such difference wa detected for Ni. This would indicate significant dissolved organic component interference by competitive complexation of Cu and Cd in the aerosol digest samples.