Diffferential pulse polarographic determination of trace elements astragalus plants

DIFFERENTIAL PULSE POLAROGRAPHIC DETERMINATION OF TRACE ELEMENTS IN ASTRAGALUS PLANTS (M. Sc. Thesis) Ali Cengiz ÇALIŞKAN GAZI UNIVERSITY ISTITUTE OF SCIENCE AND TECHNOLOGY July 2003 ABSTRACT It is well known that some Astragalus plants deposit selenium and therefore called as indicator plants for selenium. For this purpose some Astragalus plants in Turkey such as Astragalus Microcephalus and Astragalus Lusitanicus have been analyzed for their trace elements using Differential Pulse Polarographic method. One more plant Elymus Gramineae which was grown in the same soil was also analyzed. The plants were digested first with wet digestion procedure and then Fe, Cu, and Ti were determined in EDTA at pH 6; Se, Cr and Mo at pH 2; As at pH 2 and 4 in EDTA; Pb at pH 2 and 6. However, Zn could be determined at various pH values without using EDTA. The selenium content in the roots of Astragalus Microcephalus was 2-3 times larger than in the leaves. On the other hand, there was no selenium in Elymus Graminea although it was grown in the same soil. The trace elements determined were 84-183 ug/g Se, 42- 105 ug/g Cu, 350-408 ug/g Fe, 80 ug/g Zn, 56-144 ug/g Mo, 58-66 ug/g Ti, 676- 715 ug/g Cr, 110-115 ug/g As in the roots of Astragalus Microcephalus. The quantities of elements in the other plants were generally lower. Science Code : 404.03.1 Key Words : Astragalus, Selenium, Trace Elements, Differential Pulse Polarography Page Number till Advisor : Prof. Dr. Güler Somer