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A very sensitive and selective adsorptive cathodic stripping procedure for trace measurement of uranium is presented. The method is based on adsorptive accumulation of the uranium-pyromellitic acid (benzene-1,2,4,5-tetracarboxylic acid) complex onto a hanging mercury drop electrode, followed by reduction of the adsorbed species by voltammetric scan using differential pulse modulation. Influences of effective parameters such as pH, concentration of pyromellitic acid, accumulation potential and accumulation time on the sensitivity were studied. The peak current was proportional to the concentration of U(IV) up to 40 ng mL À1 with a limit of detection of 0.136 ng mL À1 with an accumulation time of 120 s. The range of linearity enhanced to 71.4 ng mL À1and the detection limit improved to 0.058 ng mL À1with accumulation times of 60 s and 300 s respectively. The relative standard deviation for 10 replicate determination of 4.76 ng mL À1 U(IV) was equal to 2.7%. The possible interference by major cations and anions are investigated. The method was applied to the determination of uranium in some analytical grade salts, seawater and in synthetic samples corresponding to some uranium alloys with satisfactory results.

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A new method is presented for determination of cadmium based on cathodic adsorptive stripping of the complex of cadmium with captopril,1-[(2S)-3-mercapto-2-methylpropionyl]-l-praline (CPL) at a hanging mercury drop electrode(HMDE). The most suitable operating conditions and parameters, such as pH, deposition potential, deposition time, ligand concentration, and others were selected and the determination of cadmium from aqueous solutions using the standard additions method was possible. Under the optimum conditions and for an accumulation time of 60 s, the measured peak current is proportional to the concentration of cadmium over the range of 1 -300 nM. The limit of detection at S/N ratio of 3 was 0.3 nM and a relative standard deviation of 2.5% at 0.1 mM was achieved. The interference of other cations and anions was studied. The method was designed in order to determination of Cd in four analytical grade salts, with satisfactory results.

N‐Phenylanthranilic acid was used as a complexing agent for determination of uranium(VI) by adsorptive cathodic stripping voltammetry. Under the optimal experimental conditions of the experimental parameters, the peak current was proportional to the concentration of U(VI) in the range 0.75–30 ng mL−1 and the detection limit was 0.036 ng mL−1. The influence of possible interferences was investigated. The method was applied for determination of uranium in waste water from uranium conversion facility and natural water samples. Application of the method for simultaneous determination of U(VI) and Cu(II) showed that these ions could be simultaneously determined in a single scan at relatively wide concentration range.