The analysis of Pb2+ and Cd2+ using SWASV was carried out in a
10.0mLaliquot using the following steps: (a) pre-conditioning step:
potential 0.0V for 60 s was applied before each measurement to
ensure dissolution of remaining deposits; (b) the pre-concentration
step proceeded at −1.1V for 180 s; (c) the square-wave anodic
stripping voltammograms were recorded when swept from −1.0 V
to 0.0V after a 20 s quiescence. Experimental parameters: deposition
potential, −1.1V; accumulation time, 180 s; square-wave
amplitude (peak to peak), 4mV; step amplitude, 25mV; frequency,15 Hz. In the pre-conditioning and pre-concentration processes, the
detection solutions were stirred with a magnetic stirrer. The peak
currents at about −0.34V for Pb2+ and −0.88V for Cd2+ were measured.