Spectrophotometric determination of iron(II) with 1,10-phenanthroline in the presence of large amounts of iron(III)

Tamura, Hiroki; Goto, Katsumi; Yotsuyanagi, Takao; Nagayama, Masaichi

doi:10.1016/0039-9140(74)80012-3

Cited by 929 publications

(463 citation statements)

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“…Under the optimized conditions, the 1:3 complexes are the dominant species. 12 Thus, Fe(II)-OP in this study denotes 1:3 complexes between Fe(II) and OP. Assuming a 1:1 molar ratio for the complexation between Fe 2+ and an arbitrary binding site in DOM (DOMi), the conditional binding constant (K′) can be defined as…”

Section: Resultsmentioning

confidence: 98%

“…12 Because OP produces a color change only when complexing with free species of Fe(II), this has been used in speciation analysis and evaluating the binding abilities of HAs to Fe(II). 13 If free Fe(II) would bind to OP in the presence of DOM, the Fe(II)-DOM complexes would undergo dissociation, and the formation of Fe(II)-OP complexes would be increased via ligand-exchange reactions.…”

Section: 11mentioning

confidence: 99%

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Binding Characteristics and Dissociation Kinetics for Iron(II) Complexes with Seawater Extractable Organic Matter and Humic Substances in a Compost

2012

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A steel-slag/compost fertilizer can be useful in supplying complex Fe(II) species to barren coastal regions. Seawater extractable organic matter (SWEOM) was examined for use as a novel chelator of Fe(II) in the compost. The dissociation kinetics for Fe(II)-SWEOM were evaluated, based on the rate of ligand-exchange with ortho-phenanthroline. The ΔH for the Fe(II)-SWEOM (19 kJ mol -1 ) was significantly smaller than the corresponding values for Fe(II) complexes with humic substances (27 kJ mol -1 ), suggesting that the Fe(II)-SWEOM is kinetically less stable.

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Section: Resultsmentioning

confidence: 98%

Section: 11mentioning

confidence: 99%

Binding Characteristics and Dissociation Kinetics for Iron(II) Complexes with Seawater Extractable Organic Matter and Humic Substances in a Compost

2012

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“…All treatments were performed in triplicate and incubated horizontally at room temperature in the dark and shaken periodically. Fe(III) reduction was monitored approximately every 24 h using the phenanthroline assay (Tamura et al, 1974; data not shown). Fe(II) formation kinetics were used as analogues for Fe(III) reduction.…”

Section: Microbial Om Ferrihydrite Reduction Experimentsmentioning

confidence: 99%

Ferrihydrite-associated organic matter (OM) stimulates reduction by <i>Shewanella oneidensis</i> MR-1 and a complex microbial consortia

et al. 2017

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Abstract. The formation of Fe(III) oxides in natural environments occurs in the presence of natural organic matter (OM), resulting in the formation of OM-mineral complexes that form through adsorption or coprecipitation processes. Thus, microbial Fe(III) reduction in natural environments most often occurs in the presence of OM-mineral complexes rather than pure Fe(III) minerals. This study investigated to what extent does the content of adsorbed or coprecipitated OM on ferrihydrite influence the rate of Fe(III) reduction by Shewanella oneidensis MR-1, a model Fe(III)-reducing microorganism, in comparison to a microbial consortium extracted from the acidic, Fe-rich Schlöppnerbrunnen fen. We found that increased OM content led to increased rates of microbial Fe(III) reduction by S. oneidensis MR-1 in contrast to earlier findings with the model organism Geobacter bremensis. Ferrihydrite-OM coprecipitates were reduced slightly faster than ferrihydrites with adsorbed OM. Surprisingly, the complex microbial consortia stimulated by a mixture of electrons donors (lactate, acetate, and glucose) mimics S. oneidensis under the same experimental Fe(III)-reducing conditions suggesting similar mechanisms of electron transfer whether or not the OM is adsorbed or coprecipitated to the mineral surfaces. We also followed potential shifts of the microbial community during the incubation via 16S rRNA gene sequence analyses to determine variations due to the presence of adsorbed or coprecipitated OM-ferrihydrite complexes in contrast to pure ferrihydrite. Community profile analyses showed no enrichment of typical model Fe(III)-reducing bacteria, such as Shewanella or Geobacter sp., but an enrichment of fermenters (e.g., Enterobacteria) during pure ferrihydrite incubations which are known to use Fe(III) as an electron sink. Instead, OM-mineral complexes favored the enrichment of microbes including Desulfobacteria and Pelosinus sp., both of which can utilize lactate and acetate as an electron donor under Fe(III)-reducing conditions. In summary, this study shows that increasing concentrations of OM in OM-mineral complexes determines microbial Fe(III) reduction rates and shapes the microbial community structure involved in the reductive dissolution of ferrihydrite. Similarities observed between the complex Fe(III)-reducing microbial consortia and the model Fe(III)-reducer S. oneidensis MR-1 suggest electron-shuttling mechanisms dominate in OM-rich environments, including soils, sediments, and fens, where natural OM interacts with Fe(III) oxides during mineral formation.

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“…Fe(II) was quantified with ferrozine (Lovley and Phillips, 1987) or by 1,10-phenanthroline assay (Tamura et al, 1974). For the quantification of dissolved Fe(III), samples were incubated in an anoxic glovebag for approximately 16 h with 0.25 M hydroxylamine-HCl/ 0.25 M HCl (Lovley and Phillips, 1987) to reduce Fe(III) to Fe(II), which was then quantified by 1,10-phenanthroline.…”

Section: Chemical Analytical Techniquesmentioning

confidence: 99%

Characterization of Fe(II) oxidizing bacterial activities and communities at two acidic Appalachian coalmine drainage-impacted sites

et al. 2008

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We characterized the microbiologically mediated oxidative precipitation of Fe(II) from coalminederived acidic mine drainage (AMD) along flow-paths at two sites in northern Pennsylvania. At the Gum Boot site, dissolved Fe(II) was efficiently removed from AMD whereas minimal Fe(II) removal occurred at the Fridays-2 site. Neither site received human intervention to treat the AMD. Culturable Fe(II) oxidizing bacteria were most abundant at sampling locations along the AMD flow path corresponding to greatest Fe(II) removal and where overlying water contained abundant dissolved O 2 . Rates of Fe(II) oxidation determined in laboratory-based sediment incubations were also greatest at these sampling locations. Ribosomal RNA intergenic spacer analysis and sequencing of partial 16S rRNA genes recovered from sediment bacterial communities revealed similarities among populations at points receiving regular inputs of Fe(II)-rich AMD and provided evidence for the presence of bacterial lineages capable of Fe(II) oxidation. A notable difference between bacterial communities at the two sites was the abundance of Chloroflexi-affiliated 16S rRNA gene sequences in clone libraries derived from the Gum Boot sediments. Our results suggest that inexpensive and reliable AMD treatment strategies can be implemented by mimicking the conditions present at the Gum Boot field site.

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Spectrophotometric determination of iron(II) with 1,10-phenanthroline in the presence of large amounts of iron(III)

Cited by 929 publications

References 12 publications

Binding Characteristics and Dissociation Kinetics for Iron(II) Complexes with Seawater Extractable Organic Matter and Humic Substances in a Compost

Binding Characteristics and Dissociation Kinetics for Iron(II) Complexes with Seawater Extractable Organic Matter and Humic Substances in a Compost

Ferrihydrite-associated organic matter (OM) stimulates reduction by <i>Shewanella oneidensis</i> MR-1 and a complex microbial consortia

Characterization of Fe(II) oxidizing bacterial activities and communities at two acidic Appalachian coalmine drainage-impacted sites

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Spectrophotometric determination of iron(II) with 1,10-phenanthroline in the presence of large amounts of iron(III)

Cited by 929 publications

References 12 publications

Binding Characteristics and Dissociation Kinetics for Iron(II) Complexes with Seawater Extractable Organic Matter and Humic Substances in a Compost

Binding Characteristics and Dissociation Kinetics for Iron(II) Complexes with Seawater Extractable Organic Matter and Humic Substances in a Compost

Ferrihydrite-associated organic matter (OM) stimulates reduction by &lt;i&gt;Shewanella oneidensis&lt;/i&gt; MR-1 and a complex microbial consortia

Characterization of Fe(II) oxidizing bacterial activities and communities at two acidic Appalachian coalmine drainage-impacted sites

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Ferrihydrite-associated organic matter (OM) stimulates reduction by <i>Shewanella oneidensis</i> MR-1 and a complex microbial consortia