Atomic Absorption Spectroscopy of Copper and Iron in Plant Material

Abstract

Abstract An atomic absorption spectroscopic (AAS) method is described for the determination of copper and iron by direct aspiration of a solution of an ashed sample in an alcohol-water mixture. The method has been applied to samples containing 2.0–31.9 μg Cu/g and 15.5–196 Fe/g. Operating conditions for using an acetylene-air flame have been established. The hollow cathode current needed to be carefully controlled for the copper analysis. No significant interference was noted from other elements commonly present in plants. Wet and dry ashing procedures provided comparable results. Recovery of added amounts of copper and iron ranged from 92 to 101% and 94 to 104%, respectively; most results were near 100%. The official AOAC colorimetric methods and the AAS method were compared and were comparable in reliability and accuracy. The AAS method is simpler and faster.