An adsorptive stripping voltammetric procedure for trace determination of uranium (U) (VI) at a hanging mercury drop electrode is described. The complex of U(VI) with Chromazorul-S was adsorbed and accumulated from an ammonia buffer solution of pH 8.8 including 2.4 ´ 10–5M Chromazorul-S at the potential !0.2 V for 120 s. After that the cathodic voltammograms were recorded by potential sweep from –0.2 to –0.9 V in the differential pulse mode. The relationship between the cathodic peak currents versus U(VI) concentrations was linear over the range of 0.7–340 ng/mL. The detection limit was 0.1 ng/mL and the relative standard deviations (7 determinations) at 10, 100, and 300 ng/mL U(VI) were 2.1, 1.6, and 1.1%, respectively. The validity of this method was estimated by determination of spiked U(VI) in natural water and soil samples. The results were successful.
