Study of interferences in the determination of lead by hydride generation-direct flame atomic-absorption spectrometry when oxidising agents are employed to increase the sensitivity

Abstract

The greatest sensitivity in the determination of lead by hydride generation-direct flame AAS is obtained in the presence of ammonium persulphate (0.012 µg). A complete interference study is reported, comparing the results obtained when hydrogen peroxide and ammonium persulphate are employed. The oxidation to a metastable tetravalent state of lead by the prior action of the oxidising agent is considered to be the mechanism by which the atomic-absorption signal in increased.