Peak area, peak current: Critical comparison. Application to real samples

The possibility of using peak area as instrumental datum for determining the concentration of metal species in solution (instead of peak height) is proposed for analytical voltammetric determinations. In this work a comparison is made between peak area and peak current in voltammetric metal determinations. The metals considered are copper(II), lead(II), cadmium(II) and zinc(II) in seawater. The influence of the instrumental parameters (pulse amplitude, electrodeposition time, stirring rate, potential scan rate, drop size, delay before sweep) on the data is studied, in order to optimize the analytical procedure. The precision and accuracy of the analytical method was tested on the reference material Sea Water BCR-CRM 403. The precision, expressed as relative standard deviation (s(r)), and the accuracy, expressed as relative error (e), were, in all cases of the order of 3 to 5%, while the detection limit was around 10(-3) mu g L-1 for all the metals.