Anodic stripping voltammetry in a flow-through cell with fixed mercury film glassy carbon disc electrodes part II. the differential mode (D.A.S.V.)

Abstract Differential anodic stripping voltammetry at a fixed glassy carbon disc electrode covered by a thin mercury film, was adapted for use in a flow-through cell. Improved sensitivity, arising from virtually perfect compensation of background currents, is demonstrated by presenting the application of the method to the determination of heavy metal ions (hydrates and/or in a labile complex form), in the 0.1–1 ng ml −1 concentration range, in sea water, using short (1–6 min) deposition periods. Good precision of results is maintained; calibration curves, within the a.m. concentration range, are linear. Due to simplicity and stability, the system seems well suited for continuous monitoring in aqueous media.