Critical Evaluation of Some Wet Digestion Methods for the Stripping Voltammetric Determination of Selenium in Biological Materials

The suitability of wet digestion methods for the cathodic stripping voltammetric determination of selenium In biological materials Is evaluated. Methods currently available for the determination of the element by other analytical techniques were found to be unreliable. However, a modified digestion procedure using a HNO₃ and H₂SO₄ mixture enables adequate digestion of the sample material and retention of selenium In a state amenable for determination and Is suitable for cathodic stripping voltammetric determination of the element In most sample materials. Application of the proposed digestion procedure to a range of biological standard reference materials provides satisfactory data.