Determination of Selenium in Food Supplements by Differential-Pulse Cathodic Stripping Voltammetry in the Presence of Added Copper
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.
MSU Digital Commons Citation
Holak, Walter and Specchio, John, "Determination of Selenium in Food Supplements by Differential-Pulse Cathodic Stripping Voltammetry in the Presence of Added Copper" (1994). Department of Nutrition and Food Studies Scholarship and Creative Works. 36.