Systematic investigation for interferences of some ions in molybdenum determination by flame atomic absorption and superpression of the interferences

SYSTEMATIC INVESTIGATION FOR INTERFERENCES OF SOME IONS IN MOLYBDENUM DETERMINATION BY FLAME ATOMIC ABSORPTION SPECTROMETRY AND SUPPRESSION OF THE INTERFERENCES (Ph.D. Thesis) Olcay ŞENDİL GAZİ UNIVERSITY INSTITUI OF SCIENCE AND TECHNOLOGY September 1994 ABSTRACT In this study, chemical interferences of Mg, Ca, Sr, Ba, Al, Cd, Mn and Fe on molybdenum determination by Flame Atomic Absorption Spectrometry (FAAS) were investigated systematicaly. The influence of these elements which causes the most important chemical interferences was therefore studied in detail. Great decrease in molybdenum absorbance was observed in the presence of alkaline earth metals. Al, Cd, Mn and Fe caused variable effects on molybdenum absor bance depending on their concentrations in the sample. Na-DDTC, NH4CI and Na2HP04 were tested to eliminate interferences on molybdenum. The usage of Na-DDTC, NH4CI and Na2HP04 supressed the interferences up to a certain inter fering elements' concentration. Molybdenum determination was performed in syn thetic sample containing interfering elements and real sample (steel) as well un der optimum experimental conditions. The accuracy and precision of results were increased reasonably by using suppressing agent. Science code : 405.03.01 Key words : Molybdenum determination, interferences, flame atomic absorption spectroscopy Page number : 107 Adviser : Prof. Dr. A. Rehber TÜRKER