Determination of Traces Cd, Pb and Cu in Beverages by

advertisement
Determination of Traces of Cd, Pb and Cu in Beverages by Differential Pulse
Anodic Stripping Voltammetry and Atomic Absorption Spectrometry
Mahmoud A. Ghandour, Azza M. M. Ali and Mohammed Abdel Aal
Chemistry Department, Faculty of Science, Assiut University, 71516-Assiut, Egypt
Email: [email protected]
Differential pulse anodic stripping voltammetry DPASV at a hanging mercury drop
electrode has been used for the determination of trace amounts of toxic heavy metals; cadmium
and lead and the essential trace element; copper in different beverages commonly consumed in
Egypt i.e. tea (black and green), coffee, cinnamon, anise, fenugreek, hibiscus(karkade) and cocoa.
The infusions of the samples have been prepared by boiling in bidistilled water. The optimal
conditions for the detection of traces of the metal ions in beverages i.e. deposition potential,
supporting electrolyte composition, effect of pH and deposition time have been studied. The
concentration of each metal ion in the samples is determined by using standard addition method.
The performance of the DPASV technique was compared with the atomic absorption
spectrometry. The precision of the method is satisfactory with relative standard deviation 1.2 %2.8 %( n=5). The average concentration of trace metal ions Cd, Pb and Cu in the samples are
varied from 0.002-0.087, 0.026-0.603 and 0.002-2.003 µg/g respectively.
Download