Brian L. Phillips

Stony Brook University, Stony Brook, New York, United States

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Publications (96)383.65 Total impact

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    ABSTRACT: Amorphous calcium carbonate (ACC) is a common transient precursor to biogenic crystalline calcium carbonate, but factors controlling the amorphous to crystalline transformation remain unclear. We present a structural analysis and comparison of hydrated and partially dehydrated, synthetic ACC samples. Thermogravimetric analysis showed total H2O losses of 46% with heating to 115 °C and 75% for heating to 150 °C. The 1H NMR spectra of hydrous ACC, obtained both directly and indirectly, via 13C-detection, contain signals from four principal hydrogen environments: translationally rigid structural H2O, a restrictedly mobile H2O environment, fluidlike mobile H2O that is decoupled from rigid H and C, and hydroxyl. The retention of some restrictedly mobile H2O and lack of change in X-ray total scattering and absorption spectroscopy data for dehydrated ACC suggest that thermal dehydration does not significantly disrupt the calcium-rich ACC framework. NMR results and thermal analyses of samples dehydrated isothermally for extended periods indicate that the H2O loss mechanism is kinetically hindered and occurs in three stages: simultaneous loss of fluidlike mobile, restrictedly mobile, and rigid H2O → loss of restrictedly mobile and rigid H2O → loss of hydroxyl and trapped rigid and mobile components that cannot be removed without transformation to crystalline calcium carbonate.
    Crystal Growth & Design 02/2014; 14(3):938–951. · 4.69 Impact Factor
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    Ning Ma, Ashaki A. Rouff, Brian L. Phillips
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    ABSTRACT: Phosphorus can be reclaimed from nutrient-rich sources as the mineral struvite (MgNH4PO4·6H2O) for reuse as fertilizer. This study determines the impact of initial pH (pHi) from 8 to 11 on the fraction of precipitated struvite from a MgCl2–(NH4)2HPO4–NaCl–H2O system. The rate of P removal from solution increases with pHi and maximizes at pHi 10. Scanning electron microscopy (SEM) of recovered precipitates shows changes in morphology and decreasing particle size with increasing pHi. 31P nuclear magnetic resonance spectroscopy (NMR) confirms that struvite constitutes 96–99% of the phosphate at pHi 8–10, with newberyite (MgHPO4·3H2O) as a minor crystalline phase. At pHi 11, 60% of the solid is struvite, with 22% of the phosphate contained in an amorphous phase and 18% as sodium phosphate. Thermogravimetric analysis (TG) reveals a correlation in the mass loss from the solids with the percentage of struvite detected. Coupling Fourier transform infrared spectroscopy (FT-IR) with TG indicates that the molar concentration of evolved H2O(g) and NH3(g) is influenced by the adsorption of NH4+(aq) at pHi 8–10 and by the low percentage of struvite at pHi 11. Overall, results indicate that both the amount of P recovered and the fraction of struvite are optimized at pHi 10. These findings can be used as a starting point in the selection of a suitable pHi for struvite recovery from nutrient-rich wastes.
    ACS Sustainable Chemistry & Engineering. 01/2014; 2(4):816–822.
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    ABSTRACT: Sorption reactions occurring at mineral/water interfaces are of fundamental importance in controlling the sequestration and bioavailability of nutrients and pollutants in aqueous environments. To advance the understanding of sorption reactions, development of new methodology is required. In this study, we applied novel 31P solid-state nuclear magnetic resonance (NMR) spectroscopy to investigate the mechanism of phosphate sorption on Al hydroxides at different environmental conditions, including pH (4 - 10), concentration (0.1 - 10 mM), ionic strength (0.001 M - 0.5 M) and reaction time (15 min - 22 d). Under these conditions, the NMR results suggest formation of bidentate binuclear inner-sphere surface complexes was the dominant mechanism. However, it was found that surface wetting caused a small difference. A small amount (<3%) of monodentate mononuclear inner-sphere surface complexes was observed in addition to the majority of bidentate binuclear surface complexes on a wet paste sample prepared at pH 5, which was analyzed in situ using a double resonance NMR technique, namely 31P{27Al} rotational echo adiabatic passage double resonance (REAPDOR). Additionally, we found that adsorbents can substantially impact phosphate sorption not only on the macroscopic sorption capacity but also on their 31P NMR spectra. Very similar NMR peaks were observed for phosphate sorbed to gibbsite and bayerite, whereas the spectra for phosphate adsorbed to boehmite, corundum and γ-alumina were significantly different. All of these measurements reveal that NMR spectroscopy is a useful analytical tool for studying phosphorus chemistry at environmental interfaces.
    Environmental Science & Technology 07/2013; · 5.26 Impact Factor
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    ABSTRACT: Total X-ray scattering and pair distribution function analysis are combined with nuclear magnetic resonance spectroscopy to identify key differences in structural properties between biogenic and synthetic samples of amorphous calcium carbonate (ACC). Biogenic samples studied are gastroliths taken from the American lobster and are composed of hydrated ACC containing minor impurities. X-ray pair distribution functions reveal that the short- and medium-range structure found in synthetic ACC also occurs in gastrolith ACC, notably with atomic pair correlations extending up to 10 Å. The 13C NMR spectra of gastrolith ACC show a distribution of carbonate environments as seen in synthetic hydrated ACC. However, 1H NMR spectroscopy reveals that a mobile H2O component and hydroxyl groups found in synthetic hydrated ACC are absent in the gastrolith ACC. This difference may arise from differences in local conditions of ACC formation. The 31P NMR results indicate that inorganic phosphate is the principal form of the minor phosphorus. Gastrolith that was allowed to age shows the presence of calcite and vaterite, as well as residual ACC. 31P NMR also reveals trace amounts of monetite (CaHPO4) in aged samples, raising the possibility that fresh gastrolith ACC may contain a minor component of amorphous calcium phosphate. The findings suggest that important differences in the hydrous components between synthetic and biogenic hydrated ACC influence stability of the amorphous phase and its transformation to crystalline forms, thereby extending the foundation for advanced materials applications in engineered systems.
    Cryst. Growth Des. 06/2013; 13(5).
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    ABSTRACT: In this research, we investigated the effects of glyphosate (GPS) on Zn sorption/precipitation on γ-alumina using a batch technique, Zn K-edge EXAFS, and 31P NMR spectroscopy. The EXAFS analysis revealed that, in the absence of GPS, Zn adsorbed on the aluminum oxide surface mainly as bidentate mononuclear surface complexes at pH 5.5, whereas Zn-Al layered double hydroxides (LDH) precipitates formed at pH 8.0. In the presence of GPS, the EXAFS spectra of Zn sorption samples at pH 5.5 and 8.0 were very similar, both of which demonstrated that Zn did not directly bind to the mineral surface but bonded with the carboxyl group of GPS. Formation of γ-alumina-GPS-Zn ternary surface complexes were further suggested by 31P solid state NMR data which indicated the GPS binds to γ-alumina via phosphonate group, bridging the mineral surface and Zn. Additionally, we showed the sequence of additional GPS and Zn can influence the sorption mechanism. At pH 8, Zn-Al LDH precipitates formed if Zn was added first and no precipitates formed if GPS was added first or simultaneously with Zn. In contrast, at pH 5.5, only γ-alumina-GPS-Zn ternary surface complexes formed regardless of whether GPS or Zn was added first or both were added simultaneously.
    Environmental Science & Technology 04/2013; · 5.26 Impact Factor
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    ABSTRACT: Phosphate sorption at the corundum (α-Al2O3)/water interface was investigated as a function of phosphate concentration (0.1–1 mM) and pH (3–11) by 31P solid state NMR spectroscopy, ATR-FTIR, and quantum chemical calculation. The 31P NMR spectra indicate that under these experimental conditions phosphate adsorbs onto corundum mainly as inner-sphere complexes that yield a peak at δP = −2.8 ppm with full width at half maximum (FWHM) of 9.2 ppm, with a small amount aluminum phosphate surface precipitates as suggested by an NMR signal observed from δP = −12 to −20 ppm. We employed 31P{27Al} rotational echo adiabatic passage double resonance (REAPDOR) to further analyze the phosphate adsorption samples prepared at pH 5 and 9 in order to determine the phosphate/Al coordination. To aid interpretation of the NMR data, a series of bidentate and monodentate structural models of phosphate adsorbed on corundum (0 0 1) and (0 1 2) surfaces were calculated using density function theory (DFT). By comparing the experimental REAPDOR curves and those simulated from these models, we can assign the dominant peaks to bidentate binuclear surface complexes. Formation of bidentate binuclear surface complexes is supported by the ATR/FTIR spectra combined with DFT calculation, which further suggests a mixture of non-protonated bidentate and mono-protonated bidentate surface complexes on the corundum surface at pH 5. At pH 9, both NMR and ATR/FTIR indicate the formation of bidentate surface complexes on corundum surface.
    Geochimica et Cosmochimica Acta 04/2013; 107:252–266. · 3.88 Impact Factor
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    ABSTRACT: Variations in speleothem P concentration show cyclic patterns that have important implications for high resolution palaeoclimate and palaeoenvironmental reconstructions. However, little is known about the speciation of P in calcite speleothems. Here we employ solid-state 31P and 1H magic angle spinning nuclear magnetic resonance (MAS NMR) spectroscopic techniques as a non-destructive method for analyzing the distribution of P in speleothems. The 31P MAS NMR results show three peaks indicating the presence of three primary types of phosphate species in samples from the Grotta di Ernesto (northeastern Italy): a broad peak at a chemical shift δP-31 = 3.1 to 3.7 ppm from individual phosphate ions incorporated within calcite, a narrow set of peaks near δP-31 = − 0.9 ppm from crystalline monetite and a narrow peak at δP-31 = 2.9 ppm from an unidentified crystalline phosphate phase. Essentially identical results were obtained for a synthetic calcite/phosphate coprecipitate. Spectra collected for a sample from Grotte de Clamouse (southern France) show only a broad peak near 3.5 ppm suggesting a possible limit for phosphate incorporation into the calcite structure. These data suggest that P in this system can interact to form calcium phosphate surface precipitates during infiltration events and are subsequently enclosed during calcite growth.
    Earth and Planetary Science Letters 01/2013; 254:313-322. · 4.72 Impact Factor
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    ABSTRACT: Sorption reactions occurring at mineral/water interfaces are of fundamental importance in controlling the sequestration and bioavailability of nutrients and pollutants in aqueous environments. To advance the understanding of sorption reactions, development of new methodology is required. In this study, we applied novel 31 P solid-state nuclear magnetic resonance (NMR) spectroscopy to investigate the mechanism of phosphate sorption on aluminum hydroxides under different environ-mental conditions, including pH (4−10), concentration (0.1−10 mM), ionic strength (0.001−0.5 M), and reaction time (15 min−22 days). Under these conditions, the NMR results suggest formation of bidentate binuclear inner-sphere surface complexes was the dominant mechanism. However, it was found that surface wetting caused a small difference. A small amount (<3%) of monodentate mononuclear inner-sphere surface complexes was observed in addition to the majority of bidentate binuclear surface complexes on a wet paste sample prepared at pH 5, which was analyzed in situ by a double-resonance NMR technique, namely, 31 P{ 27 Al} rotational echo adiabatic passage double resonance (REAPDOR). Additionally, we found that adsorbents can substantially impact phosphate sorption not only on the macroscopic sorption capacity but also on their 31 P NMR spectra. Very similar NMR peaks were observed for phosphate sorbed to gibbsite and bayerite, whereas the spectra for phosphate adsorbed to boehmite, corundum, and γ-alumina were significantly different. All of these measurements reveal that NMR spectroscopy is a useful analytical tool for studying phosphorus chemistry at environmental interfaces. ■ INTRODUCTION Phosphate is widely recognized as an essential nutrient for plants and crops and has received extensive attention. However, in the past several decades, overfertilization has caused excessive phosphate mobility from agricultural soils to water bodies, and an adverse consequence is the acceleration of lake and coastal eutrophication. 1 To effectively mitigate phosphate as a non-point-source agricultural pollutant, a good under-standing of phosphate interactions with soil minerals is necessary. In soils, phosphate anions can strongly sorb on metal (hydr)oxides, and the sorption behavior depends on the phosphate concentration, pH, ionic strength, and presence of competing ions (i.e., CO 3 2− , SO 4 2− , etc.). 2 In general, phosphate sorption mechanisms involve formation of inner-sphere surface complexes and surface precipitation. 2 In the surface complexation process, phosphate can either replace two adjacent surface hydroxyl groups (e.g., MeOH) to form bidentate binuclear bonding [(MeO) 2 −PO 2 ] or replace one to form monodentate mononuclear bonding [(MeO)−PO 3 ] (Scheme 1). Surface precipitation occurs when adsorbed phosphate ions interact with the metal ions dissolved from adsorbents 2,3 and form a new solid phase (i.e., surface precipitates). However, many details with respect to the two
    Environmental Science and Technology 01/2013; 47:8308-8315. · 5.26 Impact Factor
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    ABSTRACT: To better understand the sequestration of toxic metals such as nickel (Ni), zinc (Zn), and cobalt (Co) as layered double hydroxide (LDH) phases in soils, we systematically examined the presence of Al and the role of mineral dissolution during Zn sorption/precipitation on γ-Al(2)O(3) (γ-alumina) at pH 7.5 using extended X-ray absorption fine structure spectroscopy (EXAFS), high-resolution transmission electron microscopy (HR-TEM), synchrotron-radiation powder X-ray diffraction (SR-XRD), and (27)Al solid-state NMR. The EXAFS analysis indicates the formation of Zn-Al LDH precipitates at Zn concentration ≥0.4 mM, and both HR-TEM and SR-XRD reveal that these precipitates are crystalline. These precipitates yield a small shoulder at δ(Al-27) = +12.5 ppm in the (27)Al solid-state NMR spectra, consistent with the mixed octahedral Al/Zn chemical environment in typical Zn-Al LDHs. The NMR analysis provides direct evidence for the existence of Al in the precipitates and the migration from the dissolution of γ-alumina substrate. To further address this issue, we compared the Zn sorption mechanism on a series of Al (hydr)oxides with similar chemical composition but differing dissolubility using EXAFS and TEM. These results suggest that, under the same experimental conditions, Zn-Al LDH precipitates formed on γ-alumina and corundum but not on less soluble minerals such as bayerite, boehmite, and gibbsite, which point outs that substrate mineral surface dissolution plays an important role in the formation of Zn-Al LDH precipitates.
    Environmental Science & Technology 10/2012; · 5.26 Impact Factor
  • Wei Li, Wenqian Xu, John B. Parise, Brian L. Phillips
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    ABSTRACT: The interaction of calcium with phosphate at mineral/water interfaces is of importance for understanding both P sequestration and phosphate mineral formation. We investigated the effect of dissolved calcium on phosphate uptake by boehmite in batch sorption studies as a function of pH. Examination of the solids by 31P NMR spectroscopy and powder X-ray diffraction (XRD) shows evidence for formation of hydroxylapatite from pH 7 to pH 9, which is supported by correlation of Ca and P on particle surfaces at pH 9 observed by scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM/EDX) analysis. At pH 6, two major 31P NMR peaks are observed at δP–31 = 0 and −6 ppm, indicating the presence of bidentate binuclear complexes with surface Al atoms, similar to those found in the absence of dissolved Ca. At higher pH, an additional 31P peak at δP–31 = 2.65 ppm is observed, consistent with hydroxylapatite (Hap). The NMR data indicate that after 30 days most of the phosphate (75%) remained as adsorption complexes at pH 7, but that Hap accounts for most of the phosphate at higher pH, although surface complexes were still evident in CP/MAS NMR spectra. The identification of crystalline Hap is further supported by 31P{1H} heteronuclear correlation (HetCor) experiments in which the 2.65 ppm 31P peak correlates to a narrow 1H peak at δH–1 = 0.2 ppm that is diagnostic of the hydroxyl groups of Hap. In powder X-ray diffraction patterns, two small peaks are observed at slow scan rates that match the major reflections of Hap. Nonetheless, Hap crystals could not be identified in SEM images suggesting small particle size, in agreement with broad XRD peaks. At short reaction times only adsorbed phosphate is observed at pH 7, whereas Hap forms within 15 min at pH 9. These results indicate that the crystallization rate of Hap is enhanced by the boehmite surface, although the detailed mechanisms could not be discerned from these data.
    Geochimica et Cosmochimica Acta 05/2012; 85:289–301. · 3.88 Impact Factor
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    ABSTRACT: [ThB5O6(OH)6][BO(OH)2]·2.5H2O (Notre Dame Thorium Borate-1, NDTB-1) is an inorganic supertetrahedral cationic framework material that is derived from boric acid flux reactions. NDTB-1 exhibits facile single crystal to single crystal anion exchange with a variety of common anions such as Cl−, Br−, NO3−, IO3−, ClO4−, MnO4−, and CrO42−. More importantly, NDTB-1 is selective for the removal of TcO4− from nuclear waste streams even though there are large excesses of competing anions such as Cl−, NO3−, and NO2−. Competing anion exchange experiments and magic-angle spinning (MAS)-NMR spectroscopy of anion-exchanged NDTB-1 demonstrate that this unprecedented selectivity originates from the ability of NDTB-1 to trap TcO4− within cavities, whereas others remain mobile within channels in the material. The exchange kinetics of TcO4− in NDTB-1 are second-order with the rate constant k2 of 0.059 s−1 M−1. The anion exchange capacity of NDTB-1 for TcO4− is 162.2 mg g−1 (0.5421 mol mol−1) with a maximum distribution coefficient Kd of 1.0534 × 104 mL g−1. Finally, it is demonstrated that the exchange for TcO4− in NDTB-1 is reversible. TcO4− trapped in NDTB-1 can be exchanged out using higher-charged anions with a similar size such as PO43− and SeO42−, and therefore the material can be easily recycled and reused.
    Advanced Functional Materials 01/2012; 22:2241-2250. · 9.77 Impact Factor
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    ABSTRACT: Allophane and imogolite neogenesis in soils may occur in the presence of organic matter. To understand this process under conditions relevant to soils, the influence of dissolved organic carbon (DOC) as humic acid (HA), on aluminosilicate formation was studied at 25 C ∘ , pH 6, and low-DOC concentrations. For solutions with initial Al/Si ratios of 1–2.1, and 0–6 mg/L DOC, precipitates recovered after 20 h had Al/Si ratios of 2.2–2.7. The formation of allophane, imogolite-like material, and aluminosilicate gel was confirmed by XRD, FTIR, and NMR. The effect of DOC was to produce a small, but systematic increase in imogolite-like Si in the precipitate, and a decrease in the formation of aluminosilicate gel. Results suggest that the presence of DOC as HA slows the otherwise rapid polymerization of Al and Si at low temperature, and may also promote the formation of imogolite. The high C content of these precipitates indicates that this process may facilitate the sequestration of organic matter, slowing C cycling in soils.
    Applied and Environmental Soil Science 01/2012; 2012.
  • B.L. Phillips, Y.J. Lee, R.J. Reeder
    Environmenal Science and Technology. 01/2012; 39(12):4533-4539.
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    ABSTRACT: Structural information is important for understanding surface adsorption mechanisms of contaminants on metal (hydr)oxides. In this work, a novel technique was employed to study the interfacial structure of arsenate oxyanions adsorbed on γ-alumina nanoparticles, namely, differential pair distribution function (d-PDF) analysis of synchrotron X-ray total scattering. The d-PDF is the difference of properly normalized PDFs obtained for samples with and without arsenate adsorbed, otherwise identically prepared. The real space pattern contains information on atomic pair correlations between adsorbed arsenate and the atoms on γ-alumina surface (Al, O, etc.). PDF results on the arsenate adsorption sample on γ-alumina prepared at 1 mM As concentration and pH 5 revealed two peaks at 1.66 Å and 3.09 Å, corresponding to As-O and As-Al atomic pair correlations. This observation is consistent with those measured by extended X-ray absorption fine structure (EXAFS) spectroscopy, which suggests a first shell of As-O at 1.69 ± 0.01 Å with a coordination number of ~4 and a second shell of As-Al at ~3.13 ± 0.04 Å with a coordination number of ~2. These results are in agreement with a bidentate binuclear coordination environment to the octahedral Al of γ-alumina as predicted by density functional theory (DFT) calculation.
    Environmental Science & Technology 11/2011; 45(22):9687-92. · 5.26 Impact Factor
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    ABSTRACT: Recent development of paleo-nutrient proxies based on the phosphorus/calcium (P/Ca) ratio in tropical- and deep-water corals (also known as cold-water corals) require an understanding of the processes by which P is incorporated into the coral skeletal aragonite. Here, we apply single- and double-resonance solid-state nuclear magnetic resonance (NMR) spectroscopy to determine the speciation of P in coral aragonite. The results show that the majority of P occurs as phosphate defects in the aragonite structure, but in many samples a significant fraction of the P occurs also in crystalline hydroxylapatite inclusions. Quantification of the amount of hydroxylapatite indicates that its presence is not related simply to external environmental factors and that it can occur at varying abundances in different parts of the same corallite. Since there is currently no model available to describe the relationship between dissolved inorganic phosphate and its incorporation as apatite inclusions into carbonates, careful screening of samples which contain only phosphate in the aragonite structure or selective microsampling could improve proxy development.
    Geochimica et Cosmochimica Acta 10/2011; 75:7446-7457. · 3.88 Impact Factor
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    ABSTRACT: Systematic studies, combining batch experiments with NMR spectroscopic methods, are carried out for phosphate sorption on titanium dioxide (TiO(2)). It is found that phosphate sorption on TiO(2) decreases with increasing pH, whereas the phosphate uptake by TiO(2) increases with increasing ionic strength of the solution. In I ≤ 0.1 M, the sorption sharply increases and reaches a near maximum and then followed by little changes showing Langmuir-type behavior, whereas in I = 0.7 M, non-Langmuirian uptake becomes evident as equilibrium phosphate concentrations increase in solution. The sorption of phosphate on TiO(2) is rapid and mostly irreversible at pH 4.5 and 7.0. At pH 9.0, however, the phosphate sorption is initially reversible and followed by resorption of phosphate on TiO(2) at the system re-equilibration. (31)P{(1)H} cross-polarization and magic angle spinning (CP/MAS) NMR spectra contain at least four main peaks which appear similar in position and width under all adsorption conditions, but vary in intensity with surface loading. The spectral characteristics of these peaks, including cross-polarization dynamics and chemical shift anisotropy obtained from spinning sideband analysis, suggest that they arise from distinct inner-sphere adsorption complexes, most of which are protonated. These results indicate that uptake of phosphate by TiO(2) occurs by formation of several types of surface complexes.
    Journal of Colloid and Interface Science 08/2011; 364(2):455-61. · 3.17 Impact Factor
  • B. L. Phillips, H. E. Mason
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    ABSTRACT: Variations in the concentration of minor and trace elements are being studied extensively for potential use as proxies to infer environmental conditions at the time of mineral deposition. Such proxies rely fundamentally on a relationship between the activities in the solution and in the solid that would seem to be simple only in the case that the species substitutes into the mineral structure. Other incorporation mechanisms are possible, including inclusions (both mineral and fluid) and occlusion of surface adsorbate complexes, that might be sensitive to other factors, such as crystallization kinetics, and difficult to distinguish analytically. For example, it is known from mineral adsorption studies that surface precipitates can be nanoscopic, and might not be apparent at resolutions typical of microchemical analysis. Techniques by which a structural relationship between the substituting element and the host mineral structure are needed to provide a sound basis for geochemical proxies. NMR spectroscopy offers methods for probing such spatial relationship. We are using solid-state NMR spectroscopy to investigate phosphate incorporation in calcium carbonate minerals, including calcite speleothems and coral skeletal aragonite, at concentrations of the order 100 mug P g -1. In 31P NMR spectra of most samples, narrow peaks arising from crystalline inclusions can be resolved, including apatite in coral aragonite and an unidentified phase in calcite. All samples studied yield also a broad 31P signal, centered near chemical shifts of +3 to +4 ppm, that could be assigned to phosphate defects in the host mineral and from which the fraction of P occurring in the carbonate mineral structure can be determined. To test this assignment we applied rotational-echo double-resonance (REDOR) NMR techniques that probe the molecular-scale proximity of carbonate groups to the phosphate responsible for the broad 31P peak. This method measures dipole-dipole coupling between 31P of phosphate and carbonate carbon, which varies with the inverse-cube of the internuclear distance. 31P{13C} REDOR NMR results for synthetic phosphate/(13C)-aragonite coprecipitates show that the broad peak is closely associated with carbonate, exhibiting a 31P-13C dipolar coupling qualitatively consistent with phosphate occupying an anion structural site (i.e., 6 C at 0.32 nm). 31P-detected 1H NMR spectra, which contain signal only from H located near P, show that structural water molecules help accommodate phosphate in the structure. Similar methods can be applied to other elements of potential paleo-proxy interest having NMR-active isotopes, including B, Mg, and Cd.
    AGU Fall Meeting Abstracts. 12/2010;
  • Angewandte Chemie International Edition 08/2010; 49(34):5975-7. · 11.34 Impact Factor

Publication Stats

837 Citations
383.65 Total Impact Points

Institutions

  • 2003–2014
    • Stony Brook University
      • • Department of Geosciences
      • • Center for Environment Molecular Science
      Stony Brook, New York, United States
  • 2002–2013
    • State University of New York
      New York City, New York, United States
    • ETH Zurich
      • Institute of Terrestrial Ecosystems
      Zürich, ZH, Switzerland
  • 2012
    • University of Delaware
      • Department of Plant and Soil Sciences
      Newark, DE, United States
  • 1997–2010
    • University of California, Davis
      • • Department of Chemistry
      • • Department of Land, Air and Water Resources
      • • Department of Chemical Engineering and Materials Science
      Davis, California, United States
  • 2009
    • Pennsylvania State University
      • Department of Geosciences
      University Park, MD, United States
  • 2005
    • The University of Calgary
      • Department of Chemistry
      Calgary, Alberta, Canada
  • 2001
    • Carnegie Mellon University
      • Department of Materials Science and Engineering
      Pittsburgh, Pennsylvania, United States
  • 1997–2001
    • CSU Mentor
      Long Beach, California, United States
  • 1999
    • Christian-Albrechts-Universität zu Kiel
      Kiel, Schleswig-Holstein, Germany