In situ speciation of trace Fe(II) and Fe(III) in atmospheric waters by the FZ method coupled to GFAAS analysis

E. Journet , K.V. Desboeufs , A. Sofikitis , G. Varrault (1) , J.L. Colin

1 CEREVE - Centre d'Enseignement et de Recherche Eau Ville Environnement

A quasi-on-line method of measurement of the oxidation states of iron coupled with a GFAAS analysis is reported for the trace conditions found in atmospheric waters. This technique is based on the formation of a specific complex [Fe(FZ)3](4-) between Fe(II) and ferrozine (FZ). tC(18) solid-phase extraction cartridges (Sep-Pak) are used to separate the [Fe(FZ)3](4-) and Fe(III) so as to limit the risk of redox evolution of the sample. The adaptation to dilute aqueous media, via acidification at pH 2 of rainwater sample, and atmospheric interferences are discussed, and the Fe(II) recovery in rainwaters is determined. This method coupled with a quasi-on-line sampling protocol has been tested on rains collected in Guadeloupe Island (Caribbean Sea, 16 degrees N, 61 degrees W) during a field campaign in May 2005. Our results show that the proposed method can satisfactorily be applied to the determination of Fe(II) and Fe(III) in atmospheric waters under in situ conditions.

Domaines: Sciences de l'environnement

E. Journet, K.V. Desboeufs, A. Sofikitis, G. Varrault, J.L. Colin. In situ speciation of trace Fe(II) and Fe(III) in atmospheric waters by the FZ method coupled to GFAAS analysis. International Journal of Environmental Analytical Chemistry, 2007, 87 (9), pp.647. ⟨hal-00752719⟩