Hydride Generation Technique in Flame Atomic Absorption Spectrometry: Determination of Arsenic, Bismuth and Selenium in the Presence of Uranium Matrix

摘要

Hydride generation technique for determination of As(III), Bi(III) and Se(IV) in the presence of uranium matrix is developed using flame-atomic absorption spectrometry with air plus acetylene as oxidant-fuel combination. Several factors affecting the hydride generation efficiency in presence of uranium matrix such as effect of varying concentration of uranium matrix on absorbance, parameters of air-C2 H2 flame, HCL concentration etc. are examined. From these studies, crucially important experimental parameters are optimized for direct determination of the analyte elements in the presence of uranium matrix. This has led to the determination of As at 0.2 ppm, Bi at 0.4 and Se at 0.2 ppm on atomization in the presence of 5 mg/mL uranium matrix. The method developed here, is unique in its ability to determine these analytes without the need for chemical separation of a complex matrix such as uranium. The theoretical explanation for the atomization of analytes formation is also given in the present paper on the basis of heat of formation of hydrides and M-H bond energies vis-a-vis those of uranium.