Improvements to the Quantitative Assay of Nonrefractory Minerals for Fe(II) and Total Fe Using 1,10-Phenanthroline

Amonette, James E.

doi:10.1346/ccmn.1998.0460106

Cited by 197 publications

(121 citation statements)

References 26 publications

Supporting

Mentioning

116

Contrasting

Order By: Relevance

“…The o-P assay operates at a lower pH that is also more representative of peatland ecosystems and is thus better suited to strip DOM-complexed Fe than the ferrozine assay. The o-P complexation reaction proceeds optimally at pH 3 to 5 while the ferrozine assay occurs at pH 9.5 (Komadel and Stucki, 1988;Amonette and Templeton, 1998;Viollier et al, 2000). Thus, reduced ferrozine performance in the presence of peat humic acids may be explained by the effect of reaction pH on humic/fulvic Fe binding, and the resulting complexation equilibrium of ferrozine with Fe in the sample matrix.…”

Section: Discussion Dissolved Organic Matter Interference On Spectropmentioning

confidence: 99%

Ionic Liquid Extraction Unveils Previously Occluded Humic‐Bound Iron in Peat Soil Pore Water

Veverica

Kane

Marcarelli

et al. 2016

Soil Science Soc of Amer J

View full text Add to dashboard Cite

Globally, peatland ecosystems store tremendous amounts of C relative to their extent on the landscape, largely owing to saturated soils which limit decomposition. While there is still considerable uncertainty regarding CO 2 production potential below the water table in peatland ecosystems, extracellular Fe reduction has been suggested as a dominant pathway for anaerobic metabolism. However, colorimetric methods commonly used to quantitate Fe and partition between redox species are known to be unreliable in the presence of complex humic substances, which are common in peatland pore water. We evaluated both the standard o-phenanthroline (o-P) Method and an ionic liquid extraction (ILE) Method followed by quantitation with inductively coupled plasma optical emission spectrometry (ICP-OES) to compare total Fe recovery and Fe 2+ /Fe 3+ ratios in four distinct peatland ecosystems, ranging from rich fen to bog. While total Fe concentrations measured with ILE and o-P were correlated, the ILE method proved to be superior in both total Fe quantitation and in separately quantifying ferric (Fe 3+ ) and ferrous (Fe 2+ ) iron. In peat pore water, the o-P Method underestimated Fe 3+ by as much as 100%. A multivariate approach utilizing fluorescenceand ultraviolet (UV)-visable (Vis) spectroscopy identified indices of dissolved organic matter (DOM) humification and redox status that correlated with poor performance of the o-P Method in peat pore water. Where these interferences are present, we suggest that site-specific empirical correction factors for quantitation of total Fe by o-P can be created from ILE of Fe, but recommend ILE for accurate appraisals of iron speciation and redox processes.Abbreviations: DI, deionized; DOC, dissolved organic carbon; DOM, dissolved organic matter; EEMs, excitation-emissions matrices; FI, fluorescence index; H p , index of humification; ICP-OES, inductively coupled plasma optical emission spectrometry; ILE, ionic liquid extraction; o-P, o-phenanthroline; PARAFAC, parallel factor analysis; PCA, principal component analysis; RI, index of redox dissolved organic matter status; TEA, terminal electron acceptor; UV, ultraviolet; Vis, visible. P eatlands represent critical terrestrial C stores that are preserved by a combination of hypoxic and anoxic soil environments. These conditions present an energetic challenge for microbial consortia in anaerobic environments which utilize alternative (to oxygen) terminal electron acceptors (TEAs) during heterotrophic metabolism. In anaerobic conditions, microbes preferentially reduce several alternative TEAs for respiration, with thermodynamic yield declining in the order: NO 3 -, Mn 4+ , Fe 3+ , SO 4 2-, and ultimately CO 2 (see review by Megonigal et al., 2004). Although there is wide agreement that alternative TEA reduction is important for anaerobic decomposition, variation in the magnitudes of anaerobic CO 2 production across studies suggests that there is high variability in facultative and obligate anaerobic processes that occur below the water table (M...

show abstract

Section: Discussion Dissolved Organic Matter Interference On Spectropmentioning

confidence: 99%

Ionic Liquid Extraction Unveils Previously Occluded Humic‐Bound Iron in Peat Soil Pore Water

Veverica

Kane

Marcarelli

et al. 2016

Soil Science Soc of Amer J

View full text Add to dashboard Cite

show abstract

“…Bulk chemical extractions (Stookey, 1970;Stucki, 1981;Stucki and Anderson, 1981;Amonette and Templeton, 1998) and Mössbauer spectroscopy (Dong et al, 2000;Kukkadapu et al, 2001;Kukkadapu et al, 2004) have been used to measure the extent of microbial reduction of iron, where oxidation states are generally preserved, but these techniques give no information on the spatial distribution of oxidized and reduced metals, relative to cell surface. Dohnalkova et al (2001) attempted to preserve anaerobic states of various minerals by dehydrating, embedding, and sectioning samples in an anaerobic glove box and by excluding most fixatives and all heavy metal stains.…”

Section: Microbial Formation Of Carbonatesmentioning

confidence: 99%

Mineral-microbe interactions: a review

Dong

2010

Front. Earth Sci. China

View full text Add to dashboard Cite

The studies of mineral-microbe interactions lie at the heart of the emerging field of Geomicrobiology, as minerals and rocks are the most fundamental earth materials with which microbes interact at all scales. Microbes have been found in a number of the Earth's extreme environments and beyond. In spite of the diverse geological environments in which microbes are found and diverse approaches taken to study them, a common thread, mineral-microbe interactions, connects all these environments and experimental approaches under the same umbrella, i.e., Geomicrobiology. Minerals and rocks provide microbes with nutrients and living habitats, and microbes impact rock and mineral weathering and diagenesis rates through their effects on mineral solubility and speciation. Given a rapid growth of research in this area in the last two decades, it is not possible to provide a comprehensive review on the topic. This review paper focuses on three area, i.e., microbial dissolution of minerals, microbial formation of minerals, and certain techniques to study mineral-microbe interactions. Under the first area, three subjects are reviewed; they include siderophores as important agents in promoting mineral dissolution, microbial oxidation of reduced minerals (acid mine drainage and microbial leaching of ores), and microbial reduction of oxidized minerals. Under the second topic, both biologically controlled and induced mineralizations are reviewed with a special focus on microbially induced mineralization (microbial surface mediated mineral precipitation and microbial precipitation of carbonates). Under the topic of characterization, the focus is on transmission electron microscopy (TEM) and electron energy loss spectroscopy. It is the author's hope that this review will promote more focused research on mineral-microbe interactions and encourage more collaboration between microbiologists and mineralogists.

show abstract

“…Iron(II) and total Fe contents were determined by a photometric method recommended by Amonette and Templeton (1998). Fifty-milligram samples were dissolved by 15 mL of boiling acid matrix-containing 12 mL of 10% (w/w) H 2 SO 4 , 1 mL of 48% (w/w) HF, and 2 mL of a 10% (w/w) solution of 1,10-phenanthroline in 95% (v/v) ethanol-in 125-mL amber HDPE bottles.…”

Section: Fe(ii) and Total Fe Determinationmentioning

confidence: 99%

Potassium Fixation by Oxidized and Reduced Forms of Phyllosilicates

Florence

Ransom

Mengel

2017

Soil Science Soc of Amer J

View full text Add to dashboard Cite

Potassium fixation traps K + ions in the interlayer region of phyllosilicates. This study determined if increased negative interlayer charge caused by structural Fe reduction leads to increased K + fixation. The five reference clays used were illite (IMt-1), kaolinite (KGa-1b), montmorillonite (STx-1b), nontronite (NAu-2), and vermiculite (VTx-1). Soil clays were fractionated from the upper 15 cm of a Belvue loam and a Cherokee silt. Potassium fixation capacities were measured on clay samples of unreduced and reduced forms of each clay. Iron (II) and total Fe contents were determined, and K + fixation was measured by K saturating the clays, followed by five washes of MgCl 2 solution. Iron reduction significantly increased the amounts of K + fixed by NAu-2 and VTx-1. An increase in Fe(II) content caused increases in layer charge and K + fixation. Although NAu-2 exhibited a greater increase in Fe(II) content on reduction than VTx-1, the increase in K + fixation on reduction was greater for VTx-1 because of the tetrahedral location of Fe in VTx-1. For IMt-1, KGa-1b, and STx-1b, Fe reduction did not significantly affect the K + fixation capacities because of their low Fe contents. The Belvue loam released K + in both unreduced and reduced forms. The Cherokee silt did not appreciably release or fix K + in either form. Although much K is removed in the first wash, small amounts of K were removed in subsequent washes, especially for reduced samples of NAu-2 and VTx-1. The washing procedure caused reduced Fe to reoxidize, which resulted in K that was previously fixed to be released.Abbreviations: BEL, Belvue site; CHE, Cherokee site; HDPE, high-density polyethylene. P otassium fixation is the entrapment of K + ions in between collapsed 2:1 phyllosilicate layers (Rich, 1968). In order for layer collapse to occur, interlayer spaces need to be dehydrated. Interlayer cations dehydrate when their attraction to interlayer surfaces exceeds their attraction to their hydration shell (Kittrick, 1966;Eberl, 1980). Potassium ions and other cations such as NH 4 + , Cs + , and Rb + are readily fixed because they have relatively low energies of hydration. Thus, they can easily dehydrate. It should follow then that the greater the attraction of interlayer cations for interlayer surfaces, the greater the likelihood of cation fixation occurring. This study was conducted to test the hypothesis that increased negative interlayer charge caused by structural Fe reduction leads to increased K + fixation. Vermiculites are defined as having greater negative layer charges than smectites, and they also tend to fix more K + ions than smectites (Rühlicke, 1985;Saha and Inoue, 1998). Furthermore, vermiculites with greater layer charge have been found to have greater cation fixation capacities than vermiculites with less layer charge, and smectites with greater layer charge have been found to have greater cation fixation capacities than smectites with less layer charge (Barshad, 1954;Weir, 1965;Inoue, 1983;Eberl et al., 1986;Douglas, 1989 Core Ideas...

show abstract

Improvements to the Quantitative Assay of Nonrefractory Minerals for Fe(II) and Total Fe Using 1,10-Phenanthroline

Cited by 197 publications

References 26 publications

Ionic Liquid Extraction Unveils Previously Occluded Humic‐Bound Iron in Peat Soil Pore Water

Ionic Liquid Extraction Unveils Previously Occluded Humic‐Bound Iron in Peat Soil Pore Water

Mineral-microbe interactions: a review

Potassium Fixation by Oxidized and Reduced Forms of Phyllosilicates

Contact Info

Product

Resources

About