4. Conclusions
In the present study, the samples were lyophilized, milled and
then mineralized in a closed low temperature microwave oven.
Then the mineralized samples were dissolved in mixed acid
(HNO3 +HClO4) and Zinc and Copper concentrations were
determined by DPASV, differential pulse anodic stripping
voltammetry by Hanging Mercury drop electrode (HMDE),
using an auto sampler. DPASV has some important advantages,
such as simultaneous determination of up to 4 elements,
low contamination risk and high precision (Celik and
Oehlenschla¨ ger, 2004).
In addition, it was found that the stripping voltammetry results
indicate that the mean levels of Cd2+ and Pb2+ ions ranged
from 5.97 ngÆg1 to 23.90 ngÆg1 and from 4.03 ngÆg1 to
250.00 ngÆg1 (Nile medium parts) and also, from 6.00 ngÆg1
to 16.09 ngÆg1 and from 37.88 ngÆg1 to 121.12 ngÆg1 (Lake
medium parts), respectively. On the other hand, the mean levels
obtained using atomic absorption spectrometry of the same
elements mentioned above ranged from 6 ngÆg1 to 24 ngÆg1
(Cd) in the Nile medium parts of the Perch fishes, also, there
is no lead detected in the Nile medium parts except in the
weights of 310–355 g and from 6 ngÆg1 to 16 ngÆg1 and
38 ngÆg1 to 120 ngÆg1 (Cd and Pb) in the Lake Nasser medium
parts of Perch fishes.