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Einige systematische Fehlerquellen bei der Bestimmung von Elementen im ng- und pg-Bereich mit der Atomabsorptionsspektrometrie mit flammenloser Anregung im Graphitofen

Research paper by G. Volland, G. Kölblin, P. Tschöpel, G. Tölg

Indexed on: 01 Jan '77Published on: 01 Jan '77Published in: Analytical and Bioanalytical Chemistry



Abstract

With selected elements (Fe, Co, Ni, Ag and Cd), the serious systematic errors inherent in flameless atomic absorption spectrometry are demonstrated and their origins are discussed. Besides the parameters of the temperature program and the inert gas stream, the type and structure of the graphite, as well as its reactivity have a decisive influence on the sensitivities and limits of detection of the technique. Depression of the signal is observed with the use of strongly acid solutions and it has been attempted to explain this in connection with the reactivity of the graphite.The influence of organic solvents and organic solutions of complexes with dithizone, NH4-DDTC and APDC on the atomization have been investigated with simplified examples. It can be presumed that the resulting depression of the signal is due to losses by the formation of volatile metal-organic compounds at temperatures above 500° C. Particularly large are the losses in the presence of hydrocarbon halides as can be demonstrated by the reaction of Fe, Cd, Co, Ni, and Ag with chloroform.