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At least 433 records · Page 24

Crystalline Organic Compounds as Effective Nuclei in Contact Efflorescence of Ammonium Sulfate

Contact nucleation is believed to play a role in liquid-to-solid phase transitions in the atmosphere including ice nucleation and salt efflorescence. Here, for this work, contact efflorescence of optically levitated ammonium sulfate droplets by collisions with organic particles is probed using a long working-distance optical trap. Two highly viscous water-soluble organic compounds (d-(+)-raffinose and citric acid), and two insoluble highly surface-active organic compounds (stearic acid and cis-pinonic acid) were probed for their ability to induce efflorescence upon contact. While three of the organics showed minimal effectiveness as contact nuclei, cis-pinonic acid showed a remarkable ability to initiate contact efflorescence of ammonium sulfate, occurring near ammonium sulfate’s deliquescence relative humidity. Further analysis of cis-pinonic acid using bright-field microscopy in an electrodynamic balance provided evidence that the cis-pinonic acid particles are crystalline under the laboratory conditions. We suggest that the close lattice match between crystalline ammonium sulfate and crystalline cis-pinonic acid may account for the observed effectiveness in initiating contact efflorescence of ammonium sulfate. In contrast, tests of contact nucleation between cis-pinonic acid and sodium chloride, a pair with a poor lattice match, did not result in efflorescence. These findings suggest that crystalline organic compounds in the atmosphere could act as effective nuclei for contact efflorescence of atmospherically relevant salts, provided they share a compatible lattice structure.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Integration of a Micro-Chip Amino Acid Chirality Detector into the MOD Instrument Concept

The MOD (Mars Organic Detector) instrument concept consists of a sublimation apparatus for organic compound isolation connected to a microfabricated microfluidic analyzer containing a sipper, pumps and a separation channel for organic compound characterization. The target organic compounds are amino acids and polycyclic aromatic hydrocarbons (PAHs). Solid samples are placed within the sublimation apparatus and heated to release organic compounds which sublime onto a cold finger. Half of the cold finger is coated with fluorescamine. which reacts with amino acids and other primary amines to generate an intense fluorescent derivative while the other half is uncoated and is used to directly detect PAH fluorescence, A capillary sipper is then used to dissolve and sample the labeled amino acids and integrated microfabricated pumps transport the labeled amino acids to the chip for analysis. The sample is separated using capillary zone electrophoresis (CZE) together with chiral dextrins to determine amino acid composition and chirality. During the grant period, the following steps have been completed toward the development of a robust instrument and chemistry.

Bada, Jeffrey L.↗

Indigenous Amino Acids in Iron Meteorites

Understanding the organic content of meteorites and the potential delivery of molecules relevant to the origin of life on Earth is an important area of study in astrobiology. There have been many studies of meteoritic organics, with much focus on amino acids as monomers of proteins and enzymes essential to terrestrial life. The majority of these studies have involved analysis of carbonaceous chondrites, primitive meteorites containing approx. 3-5 wt% carbon. Amino acids have been observed in varying abundances and distributions in representatives of all eight carbonaceous chondrite groups, as well as in ungrouped carbonaceous chondrites, ordinary and R chondrites, ureilites, and planetary achondrites [1 and references therein].

carbonaceous chondrites↗

Low-cost, portable optical sensors for critical mineral prospecting and process monitoring

A combination of projected demand increases for economically critical minerals and a monopolistic global marketplace for these minerals has caused concern over supply chain vulnerabilities, which would impact energy, national defense, and advanced technology production. Domestic production of critical minerals is hindered by expensive and non-portable methods for analyzing metal concentration, which is vital both for resource prospecting and process monitoring. Here, a suite of luminescent materials along with portable instrumentation is presented for fluorescence-based detection of trace concentrations of critical minerals (cobalt, rare earth elements, and aluminum) as well as common gangue metals that are removed during processing (iron and aluminum). A metal-organic framework comprised of zinc, adenine, and trimesic acid immobilized on a fiber optic tip is capable of sensing part-per-billion concentrations of terbium, europium, dysprosium, and samarium through a sensitization approach, in which individual elements produce characteristic emission bands enabling multiple rare earths to be simultaneously detected and distinguished. A deep-UV light emitting diode is used as the excitation source, while a portable spectrometer is used to detect the emitted light. A similar optical set-up is coupled with two different carbon dot materials, which can detect low part-per-million concentrations of cobalt and iron in acidic environments. Metal-organic framework thin films comprised of copper and 2-aminoterephthalic acid are used in tandem with a portable optical set-up to further detect aluminum, with successful deployment in real fly ash leachates. Taken together, these technologies provide an inexpensive and sensitive path towards characterizing economically critical metals.

characterization and extraction of rare earth elem↗

Comets, Carbonaceous Meteorites, and the Origin of the Biosphere

The biosphere comprises the Earth s crust, atmosphere, oceans, and ice caps and the living organisms that survive within this habitat. The discoveries of barophilic chemolithoautotrophic thermophiles living deep within the crust and in deep-sea hydrothermal vents, and psychrophiles in permafrost and deep within the Antarctic Ice Sheet indicate the Earth s biosphere is far more extensive than previously recognized. Molecular biomarkers and Bacterial Paleontology provide evidence that life appeared very early on the primitive Earth and the origin of the biosphere is closely linked with the emergence of life. The role of comets, meteorites, and interstellar dust in the delivery of water, organics and prebiotic chemicals has long been recognized. Deuterium enrichment of seawater and comets indicates that comets delivered oceans to the early Earth. Furthermore, the similarity of the D/H ratios and the chemical compositions of CI carbonaceous meteorites and comets indicate that the CI meteorites may be remnants of cometary nuclei with most volatiles removed. Comets, meteorites, and interstellar dust also contain complex organic chemicals, amino acids, macromolecules, and kerogen-like biopolymers and may have played a crucial role in the delivery of complex organics and prebiotic chemicals during the Hadean (4.5-3.8 Gyr) period of heavy bombardment. The existence of indigenous microfossils of morphotypes of cyanobacteria in the CI and CM carbonaceous meteorites suggests that the paradigm that life originated endogenously in the primitive oceans of early Earth may require re-consideration. Recent data on the hot (300-400 K) black crust on comet P/Halley and Stardust images of P/Wild 2 showing depressions, tall cliffs, and pinnacles, indicate the presence of thick, durable, dark crusts on comets. If cavities within the ice and crust sustain vapor pressures in excess of 10 millibar, then localized pools of liquid water and brines could exist within the comet. Since life exists on Earth wherever there is liquid water, it is suggested that comets might also harbour viable and/or cryopreserved microbiota.

Hoover, Richard B.↗

Sensitive Amino Acid Composition and Chirality Analysis with the Mars Organic Analyzer (MOA)

Detection of life on Mars requires definition of a suitable biomarker and development of sensitive yet compact instrumentation capable of performing in situ analyses. Our studies are focused on amino acid analysis because amino acids are more resistant to decomposition than other biomolecules, and because amino acid chirality is a well-defined biomarker. Amino acid composition and chirality analysis has been previously demonstrated in the lab using microfabricated capillary electrophoresis (CE) chips. To analyze amino acids in the field, we have developed the Mars Organic Analyzer (MOA), a portable analysis system that consists of a compact instrument and a novel multi-layer CE microchip.

Skelley, Alison M.↗

Geochemical characterization of lithium deposition in fossil energy wastes

Lithium is a critical mineral used in rechargeable batteries for electric vehicles (EVs) and future modernization of electric grids with sensitive supply chains that are subject to volatility. Therefore, methods to recover lithium from domestic unconventional sources are actively being pursued in the United States. Herein, we report on the lithium recovery potential from four fossil energy waste feedstocks: oil and gas drill cuttings (sample number n = 16); oil and gas produced waters (n > 200) from Marcellus, Bakken and Permian basins; coal byproducts (n>20), such as coal ash; and acid mine drainage treatment solids (AMD solids). Select solid samples underwent sequential extraction to explore lithium hosting phases and simple organic and inorganic acid extraction to explore lithium recovery potential. Our preliminary results found lithium concentrations up to 440 mg/kg in select AMD treatment solids and up to 300 mg/L in Marcellus Shale produced waters, demonstrating these sources have lithium yield potentials comparable to conventionally mined lithium ores and brines. Sequential extractions revealed that lithium is mostly associated with clay and silicate phases in shale drill cuttings, whereas lithium resides in Fe,Mn-oxide reducible phases in AMD solids. Further, the lithium content in produced waters has a strong linear relationship with total dissolved solid (TDS) levels in three separate oil and gas basins. At the same TDS level, Marcellus Shale produced waters contain more lithium compared to Bakken Shale and Permian Basin waters, with higher percentages of Ca and Mg, major cations that might impact lithium recovery efficiencies. Our study demonstrates the heterogeneity of lithium hosts from different fossil energy wastes. Characterization results will inform future lithium recovery from these different feedstocks.

Stuckman, Mengling↗

A Hybrid Pathway to Biojet Fuel via 2,3-Butanediol

Production of biomass-derived sustainable alternative jet fuels (SAJF) has been considered as an important approach to decarbonize the aviation industry but still possesses various challenges in technology advancement, particularly in achieving high carbon efficiency. Here we report a hybrid pathway to SAJF from 2,3-butanediol (2,3-BDO), integrating biologically converting biomass to 2,3-BDO with catalytically upgrading of 2,3-BDO to jet-range hydrocarbons. This pathway is demonstrated to have a high carbon recovery to liquid hydrocarbons from corn stover (25–28%) (74–82% of the theoretical maximum efficiency). The catalytic conversion steps involve 2,3-BDO to C3+ olefins, oligomerization, and hydrogenation where the first two steps are the focus of this study. Under optimum reaction conditions (523 K, 115 kPa, 1.0 h-1 weight hourly space velocity), 2,3-BDO conversion and C3+ olefin selectivity are >97% and 94–98% during 40 h time on stream, respectively. To demonstrate the adaptability of this technology with bio-derived 2,3-BDO, we also investigated the impact of water and other organic coproducts (acetoin and acetic acid) inherited from the fermentation broth on the catalyst performance and product selectivities. We have shown that the catalyst can handle a significant amount of water in the liquid feed (40 wt% water/60 wt% 2,3-BDO) and maintain catalyst stability for ~40 h. Acetoin can be converted to similar C3+ olefins as 2,3-BDO with complete conversion of acetoin. Co-feeding 10 wt% acetoin with 2,3-BDO is found to have no impact on 2,3-BDO conversion, C3+ olefin selectivity, and catalyst stability. The utilization of organic coproduct like acetoin can help to improve overall carbon conversion efficiency when using real biomass-derived 2,3-BDO. On the other hand, the presence of 10 wt% acetic acid is shown to drastically inhibit methyl ethyl ketone (MEK) hydrogenation and butene oligomerization as revealed by the increased MEK and butene selectivities, implying the importance of separating organic acids when feeding bio-derived 2,3-BDO. The formed C3–C6 olefins from 2,3-BDO are further oligomerized over Amberlyst-36 catalyst to longer-chain hydrocarbons with >70 wt% jet-range hydrocarbons including predominantly iso-olefins/iso-paraffins. The overall carbon efficiency for the jet-range hydrocarbons is 19–22%, exceeding most of the reported biojet pathways, which makes it a promising approach for SAJF production.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗

Correlating Broadband Photoluminescence with Structural Dynamics in Layered Hybrid Halide Perovskites

The emission of white light from a single material is atypical and is of interest for solid-state lighting applications. Broadband light emission has been observed in some layered perovskite derivatives, A 2 PbBr 4 (A = R-NH 3 + ), and correlates with static structural distortions corresponding to out-of-plane tilting of the lead bromide octahedra. While materials with different organic cations can yield distinct out-of-plane tilts, the underlying origin of the octahedral tilting remains poorly understood. Using high energy resolution (e.g., quasi-elastic) neutron scattering, this contribution details the rotational dynamics of the organic cations in A 2 PbBr 4 materials where A = n-butylammonium (nBA), 1,8-diaminooctammonium (ODA), and 4-aminobutyric acid (GABA). The organic cation dynamics differentiate (nBA) 2 PbBr 4 from (ODA)PbBr 4 or (GABA) 2 PbBr 4 in that the larger spatial extent of dynamics of nBA yields a larger effective cation radius. The larger effective volume of the nBA cation in (nBA) 2 PbBr 4 yields a closer to ideal A-site geometry, preventing the out-of-plane tilt and broadband luminescence. In all three compounds, we observe hydrogen dynamics attributed to rotation of the ammonium headgroup and at a time scale faster than the white light photoluminescence studied by time-correlated single photon counting spectroscopy. This supports a previous assignment of the broadband emission as resulting from a single ensemble, such that the emissive excited state experiences many local structures faster than the emissive decay. Furthermore, the findings presented here highlight the role of the organic cation and its dynamics in hybrid organic–inorganic perovskites and white light emission.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Extraction and separation of iridium(Ⅳ) and rhodium(Ⅲ) from hydrochloric acid media by a quaternary ammonium-based hydrophobic eutectic solvent

We report the extraction and separation of iridium(IV) and rhodium(III) from hydrochloric acid solutions by a hydrophobic eutectic solvent composed of tetraheptylammonium chloride and decanoic acid have been studied for the first time. This eutectic solvent selectively extracts iridium(IV) over rhodium(III), the highest separation factor obtained is approximately 20. The effects of the main experimental factors (shaking time, the volume ratio of aqueous to organic phase, hydrochloric acid concentration, and the initial metal concentration in the aqueous phase) on the extraction behavior of iridium(IV) and rhodium(III) have been investigated. Ultraviolet–visible (UV–Vis) spectroscopy was applied to reveal the [IrCl 6 ] 2- complex to be a predominant species attributed to iridium(IV) extraction. To understand the underlying extraction mechanism, the initial iridium(IV) concentration in the aqueous phase has been varied and a corresponding mathematical model has been developed.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Methods of combined bioprocessing and related microorganisms, thermophilic and/or acidophilic enzymes, and nucleic acids encoding said enzymes

A genetically modified organism comprising: at least one nucleic acid sequence and/or at least one recombinant nucleic acid isolated from Alicyclobacillus acidocaldarius and encoding a polypeptide involved in at least partially degrading, cleaving, transporting, metabolizing, or removing polysaccharides, cellulose, lignocellulose, hemicellulose, lignin, starch, sugars, sugar oligomers, carbohydrates, complex carbohydrates, chitin, heteroxylans, glycosides, xylan-, glucan-, galactan-, or mannan-decorating groups; and at least one nucleic acid sequence and/or at least one recombinant nucleic acid encoding a polypeptide involved in fermenting sugar molecules to a product. Additionally, enzymatic and/or proteinaceous extracts may be isolated from one or more genetically modified organisms. The extracts are utilized to convert biomass into a product. Further provided are methods of converting biomass into products comprising: placing the genetically modified organism and/or enzymatic extracts thereof in fluid contact with polysaccharides, cellulose, lignocellulose, hemicellulose, lignin, starch, sugars, sugar oligomers, carbohydrates, complex carbohydrates, chitin, heteroxylans, glycosides, and/or xylan-, glucan-, galactan-, or mannan-decorating groups.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Indirect Routes to Aminoacyl-tRNA: The Diversity of Prokaryotic Cysteine Encoding Systems

Universally present aminoacyl-tRNA synthetases (aaRSs) stringently recognize their cognate tRNAs and acylate them with one of the proteinogenic amino acids. However, some organisms possess aaRSs that deviate from the accurate translation of the genetic code and exhibit relaxed specificity toward their tRNA and/or amino acid substrates. Typically, these aaRSs are part of an indirect pathway in which multiple enzymes participate in the formation of the correct aminoacyl-tRNA product. The indirect cysteine (Cys)-tRNA pathway, originally thought to be restricted to methanogenic archaea, uses the unique O -phosphoseryl-tRNA synthetase (SepRS), which acylates the non-proteinogenic amino acid O -phosphoserine (Sep) onto tRNA Cys . Together with Sep-tRNA:Cys-tRNA synthase (SepCysS) and the adapter protein SepCysE, SepRS forms a transsulfursome complex responsible for shuttling Sep-tRNA Cys to SepCysS for conversion of the tRNA-bound Sep to Cys. Here, we report a comprehensive bioinformatic analysis of the diversity of indirect Cys encoding systems. These systems are present in more diverse groups of bacteria and archaea than previously known. Given the occurrence and distribution of some genes consistently flanking SepRS, it is likely that this gene was part of an ancient operon that suffered a gradual loss of its original components. Newly identified bacterial SepRS sequences strengthen the suggestion that this lineage of enzymes may not rely on the m 1 G37 identity determinant in tRNA. Some bacterial SepRSs possess an N-terminal fusion resembling a threonyl-tRNA synthetase editing domain, which interestingly is frequently observed in the vicinity of archaeal SepCysS genes. We also found several highly degenerate SepRS genes that likely have altered amino acid specificity. Cross-analysis of selenocysteine (Sec)-utilizing traits confirmed the co-occurrence of SepCysE and the Sec-utilizing machinery in archaea, but also identified an unusual O -phosphoseryl-tRNA Sec kinase fusion with an archaeal Sec elongation factor in some lineages, where it may serve in place of SepCysE to prevent crosstalk between the two minor aminoacylation systems. These results shed new light on the variations in SepRS and SepCysS enzymes that may reflect adaptation to lifestyle and habitat, and provide new information on the evolution of the genetic code.

59 BASIC BIOLOGICAL SCIENCES↗

The search for life in the solar system

The search for extraterrestrial life in the solar system is reviewed in the light of present knowledge about the physical state of the planets. Arguing that all life in the universe is based on carbon chemistry, the carbon abundance in the solar system is discussed along with the composition of the planets, the presence of organic compounds (particularly amino acids) in meteorites, and the existence of complex organic compounds in interstellar space. Prospects for life in the solar system are evaluated by eliminating most of the bodies as potential biological habitats on the basis of temperature and lack of an atmosphere. Bodies eliminated in this manner include the moon, most of the other satellites, Mercury, Venus, the asteroids, and the giant planets. It is shown that the outlook for life on Titan is uncertain, but that Mars fulfills the minimum conditions for a life-bearing planet. Theories on the Martian surface environment are reviewed, the problem of the lack of water on Mars is examined, and the possibility of climatic changes is considered. The Viking mission is briefly noted.

Horowitz, N. H.↗

Coprecipitation of Fe/Cr Hydroxides at Organic–Water Interfaces: Functional Group Richness and (De)protonation Control Amounts and Compositions of Coprecipitates

Iron/chromium hydroxide coprecipitation controls the fate and transport of toxic chromium (Cr) in many natural and engineered systems. Organic coatings on soil and engineered surfaces are ubiquitous; however, mechanistic controls of these organic coatings over Fe/Cr hydroxide coprecipitation are poorly understood. Here, Fe/Cr hydroxide coprecipitation was conducted on model organic coatings of humic acid (HA), sodium alginate (SA), and bovine serum albumin (BSA). The organics bonded with SiO 2 through ligand exchange with carboxyl (-COOH), and the adsorbed amounts and pK(a) values of -COOH controlled surface charges of coatings. The adsorbed organic films also had different complexation capacities with Fe/Cr ions and Fe/Cr hydroxide particles, resulting in significant differences in both the amount (on HA > SA(-COOH) >> BSA(-NH 2 )) and composition (Cr/Fe molar ratio: on BSA(-NH2) >> HA > SA(-COOH)) of heterogeneous precipitates. Negatively charged -COOH attracted more Fe ions and oligomers of hydrolyzed Fe/Cr species and subsequently promoted heterogeneous precipitation of Fe/Cr hydroxide nanoparticles. Organic coatings containing -NH 2 were positively charged at acidic pH because of the high pK(a) value of the functional group, limiting cation adsorption and formation of coprecipitates. Meanwhile, the higher local pH near the -NH 2 coatings promoted the formation of Cr(OH) 3 . Finally, this study advances fundamental understanding of heterogeneous Fe/Cr hydroxide coprecipitation on organics, which is essential for successful Cr remediation and removal in both natural and engineered settings, as well as the synthesis of Cr-doped iron (oxy)hydroxides for material applications.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Nanoflow Separation of Amino Acids for the Analysis of Cosmic Dust

The delivery of amino acids to the early Earth by interplanetary dust particles, comets, and carbonaceous meteorites could have been a significant source of the early Earth's prebiotic organic inventory. Amino acids are central to modern terrestrial biochemistry as major components of proteins and enzymes and were probably vital in the origin of life. A variety of amino acids have been detected in the CM carbonaceous meteorite Murchison, many of which are exceptionally rare in the terrestrial biosphere including a-aminoisobutyric acid (AIB) and isovaline. AIB has also been detected in a small percentage of Antarctic micrometeorite grains believed to be related to the CM meteorites We report on progress in optimizing a nanoflow liquid chromatography separation system with dual detection via laser-induced-fluorescence time of flight mass spectrometry (nLC-LIF/ToF-MS) for the analysis of o-phthaldialdehydelN-acetyl-L-cysteine (OPA/NAC) labeled amino acids in cosmic dust grains. The very low flow rates (<3 micro-L/min) of nLC over analytical LC (>0.1 ml/min) combined with <2 micron column bead sizes has the potential to produce efficient analyte ionizations andchromatograms with very sharp peaks; both increase sensitivity. The combination of the selectivity (only primary amines are derivatized), sensitivity (>4 orders of magnitude lower than traditional GC-MS techniques), and specificity (compounds identities are determined by both retention time and exact mass) makes this a compelling technique. However, the development of an analytical method to achieve separation of compounds as structurally similar as amino acid monomers and produce the sharp peaks required for maximum sensitivity is challenging.

Martin, M. P.↗

Structurally Driven Selective Adsorption of Hydrocarbons by Metal Substitution in Isostructural Rare-Earth Metal–Organic Frameworks

The design and realization of highly selective nanoporous materials are necessary to target critical separations across industries. By leveraging pore size, pore shape, and linker functionalization, the design of nanoporous solid adsorbents will enable the rapid production of energy efficient separation materials for high-value gas mixtures. This study uses a combination of modeling, synthesis, and gas adsorption testing to investigate a new class of small-pore isostructural rare-earth (RE) 2,5-dihydroxyterephthalic acid (DOBDC) metal–organic frameworks (MOFs) (RE: Pr-, Gd-, Er-, Yb; DOBDC = 2,5-dihydroxyterephthalic acid) and their adsorption selectivity for acetylene/ethylene mixtures. Density functional theory simulations identified that selective binding of acetylene over ethylene in the Gd-, Er-, and Yb-DOBDC MOFs was due to hydrogen-bonding between acetylene and the linker hydroxyl. Adsorption experiments validated the computational results by identifying mechanisms that control the acetylene/ethylene adsorption selectivity and high acetylene adsorption. Furthermore, dynamic column breakthrough experiments with the Gd-DOBDC MOF validated the simulations and indicated that ethylene can be separated from acetylene in a mixture containing 1 vol % acetylene and 39 vol % ethylene (balance argon). In conclusion, the results highlight the complexity of gas binding in functional porous materials and how combining modeling and experiment enables a fundamental understanding of gas–framework interactions that can be leveraged for the design of future separation materials.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗