The voltammetric behavior of captopril in presence of
copper ions was investigated by using adsorptive cathodic stripping
voltammetry at hanging mercury drop electrode.
This research study the effect of the most important conditions on the voltammetric curves of lead and copper to reach the optimal conditions for the simultaneous determination of these elements by Differential pulse anodic stripping voltammetry (DPA
SV) using a hanging mercury drop electrode (HMDE) as a working electrode.
The results showed that the optimal conditions for the simultaneous determination of lead and copper by using nitric acids electrolyte 3M,were when applying scanning field from -700 mV to +150 mV, accumulation potential -800 mV, the time of the accumulation 80 sec, speed rate 40 mV/sec, and the amplitude pulse 70mV,
where the peak currents were IP (Pb) = 274.2 nA, IP (Cu) = 630.5 nA, at peak potentials EP (Pb) = -380 mV, EP (Cu) = +40 mV, by applying the previous conditions, the limits of detection reached 1.05μg/l for lead 2.45 μg/l for copper. The retrieval coefficient calculated to make sure accuracy of the method and it reached 103.90% and copper 101.70% and to indicate the precision of the way by the standard deviation was the value of the standard deviation for lead 0.027 mg/l, and copper 0.013 mg/l. the method applied under its own conditions by examined on some of environmental and samples and showed success and high efficiency
This research studying the effect of the most important analytical and technical conditions on the voltammetric curves of lead and cadmium in order to choose the optimal conditions for the simultaneous determination of these two elements by Different
ial pulse anodic stripping voltammetry (DPASV) using Graphite mercury film electrode(GMFE) as a working electrode. The results showed that the optimum analytical conditions were when using Sodium acetate - acetic acid (0.05M) electrolyte, where pH= 4.6, and a concentration (25mg/l) of Hg2+, CCd:CPb ratio up to 1:10 and conversely, and the optimum technical conditions were when applying scanning field from -1200 to -100mV, accumulation potential Eacc= -1200mV, accumulation time tacc= 120sec, speed rate υ= 120mV/sec, and amplitude pulse ΔE= 50mV. The previous conditions gave ideal voltammetric curves, Ip(Cd)= 6.134µA, Ip(Pb)= 4.966µA, Ep(Cd) = -647 mV, Ep(Pb)= -473 mV. The previous conditions were applied on a standard sample and the limit of detection was (Cd) 0.100µg/l, (Pb) 1.000µg/l, retrieval coefficient R%(Cd)= 100.5%, R%(Pb)= 97.2%, standard deviation SD(Cd)= 0.020mg/l, SD(Pb)= 0.021mg/l; Therefore, that shows the accuracy and precision of the method. The validity of the method under its new conditions was examined on a number of environmental samples and showed success and high efficiency.
