Determination of Traces of Uranium in Environmental Samples Using a Flow Injection System with Amperometric Catalytic Detection

✍ Scribed by Marco A. S. Aguiar; Karem S. G. Marquez; Ivano G. R. Gutz

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 267 KB
• Volume: 12
• Category: Article
• ISSN: 1040-0397
• DOI: 10.1002/1521-4109(200006)12:10<742::aid-elan742>3.0.co;2-z

✦ Synopsis

A new method for ¯ow 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 LiNO 3 and the electrolyte for the samples was 10 mM HNO 3 10 mM LiNO 3 . The method is simple, rapid (up to 60 injections=h) and precise (RSD 1.0 % for n 10 and C U 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 hydro¯uoric 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.