Collection and Partial Characterization of Volatile Selenium Compounds from Medicago Sativa L.

Abstract

Tops and roots of Medicago sativa plants raised in culture solution to which 75Se-labelled selenite or selenate had been added were shown to release 0.5-3.0% of their total selenium in volatile form when dried at 70[degree]C for 48 hr. The volatile selenium compounds were collected on activated charcoal. Extraction of the charcoal with various solvents showed that a large part of the total volatile selenium-containing material was soluble in water but insoluble in diethyl ether. The residual moiety was soluble in ether by insoluble or sparingly soluble in water. The water-soluble fraction was shown to contain 2 selenium compounds which could be separated by anion-exchange column chromatography. The same 2 water-soluble volatile compounds were found whether selenium was supplied to the plants as selenite or selenate and whether collected from over-drying tops or roots. The same 2 compounds were also obtained from intact plants. The chromatographic method used to separate these compounds also separated inorganic selenite and selenate from them and from each other.