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A new method for flow injection analysis (FIA) of traces of uranium by catalytic amperometric detection in nitrate medium is described. Interfering oxygen was removed by in‐line degassing. A simple adapter was designed to afford FIA with batch cells comprising a hanging mercury drop electrode. The carrier electrolyte consisted of 10 mM LiNO3 and the electrolyte for the samples was 10 mM HNO3+10 mM LiNO3. The method is simple, rapid (up to 60 injections/h) and precise (RSD=1.0 % for n=10 and CU=80 nM), presenting a LD of 13 pg of U or 3 nM (3 SD). Dissolution of solid samples (rock and soil) was abbreviated by employing a mixture of nitric and hydrofluoric acids in microwave heated closed vessels, followed by liquid‐liquid extraction with TBP. Analysis of reference materials and intercomparison with other techniques gave very favorable results.

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