Simultaneous measurement of lead and cadmium in the milk distributed in Tehran’s schools by differential-pulse anodic stripping voltammetry

Abstract

Milk is one of the most important foods in the dietary regimen of children which can be contaminated with toxic elements such as lead (Pb) and cadmium (Cd). In this study, the concentrations of Cd and Pb were determined in the milk distributed among school-aged children in Tehran. Differential-pulse anodic stripping voltammetry (DPASV) method using hanging mercury drop electrode (HMDE) was performed. The obtained limit of detection (LOD) and limit of quantification (LOQ) were 0.31 ppb and 1.03 ppb for Pb and 0.09 ppb and 0.32 ppb for Cd, respectively. The concentration of Pb and Cd in the examined milk was 3.34 ± 0.63, and 0.42 ± 0.47 ppb, with recovery range between 85-109% and 91-112%, respectively. The results demonstrated that the levels of Pb and Cd were considerably less than the maximum residue limit (MRL), mentioned by the regulatory organizations.