Determination of sub-nanomolar concentrations of lead by anodic-stripping voltammetry at the silver electrode Original Research Article

The determination of lead at the nanomolar level by square-wave anodic-stripping voltammetry (SWASV) without removal of oxygen has been extended to the sub-nanomolar concentration range. The detection limit has been lowered with the use of a method of differences (SWASV_D) to 0.05 nM (10 ng l−1) at 60 s electrodeposition. In this method the analytical signal is the difference between the voltammogram of the sample and that obtained with no electrolysis, recorded sequentially. Measurements at the sub-nanomolar concentration level, including standard-addition plots, are performed in a rapid sequence enabled by the “Project” option of the GPES-μAutolab software.