Analysis of Biological Tissues for Selenium by Thin Layer Chromatography

Abstract

Selenium is oxidized by the method of Poole¹ as modified by Stahr, et al⁴ to free it from matrix encumbrances. It is reduced by HC1 dissolution and complexed with DAN (Diaminonapthalene) then extracted into cyclohexane and analyzed by TLC (reverse phase Whatman high performance plates) thin layer chromatography densitometry. TLC allows observation of 0.1 ng of the selenium (piazselenole) complex. Separation of the Se containing complex allows elimination of other potentially interfering fluorescent compounds. 100% recoveries of Se⁷⁵ (radiolabelled) are achieved through the digest step and 85–90% are achieved through the complete test. Radioautography shows only the gold piazselenole spot contains selenium. Agreement with Bureau of Standards results on freeze dried liver is 100% ± 2%.