INVESTIGATIONS ON THE CHOICE OF THE ADEQUATE PHYSICOCHEMICAL MATRIX MODIFIER FOR THE DETERMINATION OF BISMUTH BY ELECTROTHERMAL ATOMIC-ABSORPTION SPECTROMETRY

We have studied 12 matrix modifiers for the determination of bismuth. Quite unexpectedly, cadmium and lead improved the peak shape and enhanced somewhat the peak height and area. Molybdenum, zinc and cobalt gave double peaks and are not recommended as modifiers. Palladium delays the appearance and the peak temperature, but at the same time it flattens the peak thus decreasing the peak height and area. The information provided by the examination of the peak shape proved essential for the selection of the optimal stabilizing agent in any given application. It is suggested that no "universal" matrix modifier exists.