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

Abstract

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 ] 4À between Fe(II) and ferrozine (FZ). tC 18 solid-phase extraction cartridges (Sep-Pak) are used to separate the [Fe(FZ) 3 ] 4À 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 ¼ 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 N, 61 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.

Redox speciation analysis of dissolved iron in estuarine and coastal waters with on-line solid phase extraction and graphite furnace atomic absorption spectrometry detection

“…In the developed on-line coupled systems, SPE columns are packed with silica-immobilized 8-hydroxyquinoline [20] or Chelex-100 resin [21] for determination of total dissolved iron or Fe(III) only. In a recent study, speciation of Fe(II) and Fe(III) in atmospheric water utilizing the FZ method and off-line GFAAS analysis is reported [22]. Fe(II) is retained on a FZ conditioned cartridge and eluted with a water-methanol solution.…”

Labile Fe(II) concentrations in the Atlantic sector of the Southern Ocean along a transect from the subtropical domain to the Weddell Sea Gyre

“…Biotic in situ processes include bioreduction of organic Fe (III) at cell surface Price, 1999, 2001;Shaked et al, 2004;Morel et al, 2008), reduction by biogenic superoxide Waite, 2002, 2003;Salmon et al, 2006), as well as remineralization via microbial activity (Alldredge and Cohen, 1987), cell lysis (Gobler et al, 2002), and grazing (Hutchins and Bruland, 1994;Hutchins et al, 1995;Sarthou et al, 2008). The external sources are atmospheric inputs (Kieber et al, 2001;Journet et al, 2007;Ozsoy and Saydam, 2001), sediment inputs (Elrod et al, 2004;Lohan and Bruland, 2008), submarine groundwater discharge (Windom et al, 2006), and hydrothermal vents (Coale et al, 1991;Chin et al, 1994;Field and Sherrell, 2000;Statham et al, 2005;Bennett et al, 2008). These sources supply Fe(II), which can then be transported by advective and/or diffusive mixing.…”

Non-chromatographic atomic spectrometric methods in speciation analysis: A review

“…Thus, the total Fe content could be determined without the need for preoxidation of Fe(II) to Fe(III), and Fe(II) calculated by difference. A similar method was used by Journet et al [84] wherein both Fe (II) and Fe(III) were determined in atmospheric waters, based on the formation of a specific complex [Fe(FZ)3](4-) between Fe(II) and ferrozine (FZ).…”