Determination of selenium in food supplements by differential-pulse cathodic stripping voltammetry in the presence of added copper

Walter Holak, John Specchio

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Selenium was determined by cathodic stripping voltammetry in a 1 mol l -1 HCl acid solution containing added CuII. In this medium, selenium was preconcentrated on the hanging mercury drop electrode and stripped cathodically in differential-pulse mode. After a deposition period of 1 min, 0.2 ng ml-1 of selenium could be detected. The method was applied to the analysis of food supplements. Total selenium was determined after digestion of the sample with HNO3 - HClO4 and reduction to the electroactive SeIV by heating with HCl. Inorganic selenium (i.e., selenite and selenate) was similarly determined after extraction with dilute sodium hydroxide solution and clean-up on activated carbon. Representative over-the-counter preparations have been analysed.

Original languageEnglish
Pages (from-to)2179-2182
Number of pages4
JournalThe Analyst
Issue number10
Publication statusPublished - 1 Dec 1994


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