Results (
Thai) 1:
[Copy]Copied!
3.2.2. Interferences and validation of the method
The effect of co-existing ions in the determination of copper was investigated. More than 18 ions were examined for their possible interferences in the determination of 10.0 μg L−1
copper under optimum
conditions (pH 3.6; Eacc −0.30 V; tacc 30 s; CLA 1.0 μmol L−1
). The tolerance limit was defined as the concentration that gave a change ≤5.0% in
the peak current of the Cu–LA complex. When the concentration of
Cd(II) and Mo(VI) was 100.0 μg L−1
the peak current decreased N5.0%.
However, the presence of EDTA eliminates this effect. Nevertheless, a
concentration of EDTA of 100.0 μmol L−1
decreases the current peak
of Cu–LA complex in 10%. Antimony interferes in the presence or absence of EDTA; however, its concentration in natural samples is very
low. On the other hand, if the sample is digested the peak current of
Cu–LA is not affected by the presence of Sb (100.0 μg L−1
).
Being translated, please wait..