Ion-exchange Phase Research Articles

Conversion of glycerol to aromatic hydrocarbons over Zn-promoted HZSM-5 catalysts

Catalytic conversion of glycerol to BTX aromatics has been investigated over HZSM-5 and Zn-promoted HZSM-5 catalysts. The reaction pathway of glycerol to aromatics was proposed. Glycerol was first dehydrated to three main intermediates, propenal, acetaldehyde, and acetol. The combination of oxygenate pool and olefins formed heavy aromatics in the hydrocarbon pool via oligomerization and cyclization. The disproportion and cracking of the hydrocarbon pool generated aromatics and also short alkanes. The effects of zeolite acid properties to the aromatization of glycerol were investigated over HZSM-5 with various SiO2/Al2O3 ratios i.e. 23, 30, 50, 80, and 280. In order to improve the aromatics selectivity, the dehydrogenation metal, Zn was promoted on the HZSM-5 zeolites by both aqueous phase ion-exchange (IE) and incipient wetness impregnation (IWI) methods. XPS, EXAFS, H2-TPR, NH3–TPD and TPD-IPA (temperature programmed desorption of isopropylamine) were employed to investigate the active species of Zn in aromatization of glycerol. By using aqueous phase ion-exchange method, the appearance of Zn species was only in the form of bivalent Zn cations at exchange site. Due to the exchange of these species with strong Brönsted acid site, the formation of aromatics tended to increase by suppressing the hydrogen transfer reaction and formation of light paraffins. ZnO species, formed by incipient wetness impregnation method was found to be less active for the reaction.

Systemic toxic effects induced by the aqueous extract of the fire coral Millepora complanata and partial purification of thermostable neurotoxins with lethal effects in mice

Millepora complanata is a cnidarian widely distributed in the coral reefs of the Mexican Caribbean. This species is popularly known as “fire coral”, since contact with it causes severe pain, skin eruptions and blisters. Intravenous administration of of M. complanata aqueous extract induces violent convulsions and death in mice within 1 min (LD50=4.62µgprotein/g of body weight). Doses less than the LD50 produced histopathological damage in kidneys and lungs. Such histopathological damage was completely eliminated after incubation of the extract in heat denaturing conditions. Unexpectedly, the denatured extract conserved its lethal effect. These findings demonstrated that the extract contained hemolytic and phospholipase activities that might be responsible for the histopathological damage, and additionally it contained other unidentified thermostable toxins with lethal effects in mice. Chromatographic analysis of the extract led to the isolation of a 61kDa vasoconstrictor protein. Furthermore, several non-peptidic vasoconstrictor fractions were separated. Particularly interesting was the fraction MC1-IIA obtained as a result of three-step chromatography processes (ion exchange, gel filtration and reverse phase). Like the original crude extract, this fraction induced vasoconstriction and delayed hemolysis and lethal effects in mice. A subsequent chromatographic analysis of MC1-IIA showed that this fraction contained at least four non-peptidic compounds. MS and NMR spectroscopic data analyses indicated that these metabolites were poly-oxygenated alkylbenzenes. The present study constitutes the first report of the presence of non-peptidic lethal toxins in an organism of the class Hydrozoa, and evidences the great structural diversity of the toxins produced by the Millepora species.

Porous polymer monolithic columns with gold nanoparticles as an intermediate ligand for the separation of proteins in reverse phase-ion exchange mixed mode

A new approach has been developed for the preparation of mixed-mode stationary phases to separate proteins. The pore surface of monolithic poly(glycidyl methacrylate-co-ethylene dimethacrylate) capillary columns was functionalized with thiols and coated with gold nanoparticles. The final mixed mode surface chemistry was formed by attaching, in a single step, alkanethiols, mercaptoalkanoic acids, and their mixtures on the free surface of attached gold nanoparticles. Use of these mixtures allowed fine tuning of the hydrophobic/hydrophilic balance. The amount of attached gold nanoparticles according to thermal gravimetric analysis was 44.8wt.%. This value together with results of frontal elution enabled calculation of surface coverage with the alkanethiol and mercaptoalkanoic acid ligands. Interestingly, alkanethiols coverage in a range of 4.46–4.51molecules/nm2 significantly exceeded that of mercaptoalkanoic acids with 2.39–2.45molecules/nm2. The mixed mode character of these monolithic stationary phases was for the first time demonstrated in the separations of proteins that could be achieved in the same column using gradient elution conditions typical of reverse phase (using gradient of acetonitrile in water) and ion exchange chromatographic modes (applying gradient of salt in water), respectively.

Coupling solid-phase microextraction with ambient mass spectrometry using surface coated wooden-tip probe for rapid analysis of ultra trace perfluorinated compounds in complex samples.

Coupling solid-phase microextraction (SPME) with ambient mass spectrometry using surface coated wooden-tip probe was achieved for the first time and applied in the analysis of ultra trace perfluorinated compounds (PFCs) in complex environmental and biological samples. We modified n-octadecyldimethyl[3-(trimethoxysilyl)propyl]ammonium chloride on the surface of sharp wooden tip via silanization to form a novel SPME probe, which was then used for highly selective enrichment of PFCs from complex matrices and applied as a solid substrate to induce electrospray ionization for mass spectrometric analysis. The porous structural surface together with the dual extraction mechanisms (reversed phase adsorption and ion exchange adsorption) demonstrated that the SPME probe has an outstanding enrichment capacity, enhancing sensitivity by approximately 4000-8000 folds for the detection in aqueous samples, and 100-500-fold in whole blood and milk samples. The method showed good linearity, with correlation coefficient values (r(2)) of no less than 0.9931 for eight target PFCs. The limits of detection and qualification of the eight PFCs were 0.06-0.59 and 0.21-1.98 ng/L, respectively. Quantification of real samples was achieved by isotope internal standard calibration curve method or isotope dilution method, and ultratrace levels of PFCs present in lake water, river water, whole blood, and milk samples had been successfully detected and qualified.

First Successful Application of the Thallous Ion Exchange (TIE) Method. Preparation of Fully Indium-Exchanged Zeolite Y (FAU, Si/Al = 1.69)

Fully indium-exchanged zeolite Y, |In+62.6(In57+)1.2|[Si121Al71O384], was prepared by thallous ion exchange (TIE), a vapor phase ion exchange method. InCl(g, 510 Pa) was allowed to react with a single crystal of Tl71–Y under anhydrous conditions at 623 K. A second crystal prepared as above was washed with deionized water and redehydrated to give |In+39.7 (In57+)4.5|[Si121Al71O384]. The structures of fully dehydrated Tl71–Y and these two forms of In–Y were determined by single-crystal crystallography using synchrotron X-radiation. Then the two In–Y crystals were subjected to scanning electron microscopy energy-dispersive X-ray (SEM-EDX) analysis. Both methods indicated that no Tl remained in the In–Y crystals. The additional steps of washing and redehydration caused some of the In+ ions in the first In–Y crystal to disproportionate to give additional In57+ clusters in the sodalite cavities and In0 atoms on the crystal surface. Most of the In+ ions in both forms of In–Y are easily accessible to guest molecu...

Comparison of membrane-bound and soluble polyphenol oxidase in Fuji apple (Malus domestica Borkh. cv. Red Fuji)

This study compared membrane-bound with soluble polyphenol oxidase (mPPO and sPPO, respectively) from Fuji apple. Purified mPPO and partially purified sPPO were used. mPPO was purified by temperature-induced phase partitioning and ion exchange chromatography. The specific activity of mPPO was 34.12× higher than that of sPPO. mPPO was more stable than sPPO at pH 5.0–8.5. Although mPPO was more easily inactivated at 25–55°C, it is still more active than sPPO in this temperature range. The optimum substrate of mPPO was 4-methyl catechol, followed by catechol. l-cysteine had the highest inhibitory effects on mPPO followed by ascorbic acid and glutathione. Surprisingly, EDTA increased mPPO activity. The results revealed that purified mPPO is a dimer with a molecular weight of approximately 67kDa.

Determination of Amino Acids in Corn Seed by Gas Chromatography–Mass Spectrometry

A gas chromatography–mass spectrometry method was developed for the determination of free amino acids from corn inbred lines flour. Amino acids were extracted using 6% trichloroacetic acid. The extracts were purified using an ion-exchange solid phase, derivatized as trifluoroacetic butyl esters, and analyzed. The 15N-methionine was used as the internal standard. The method was repeatable for most of the amino acids (coefficient of variation was in the order of 20%), and good accuracy and limits of detection were obtained. Among the free amino acids determined, the highest concentrations were obtained for aspartic acid, proline, gamma-aminobutyric acid, lysine, alanine, glutamic acid, and histidine. The study established the variation of the free amino acids within the inbred lines.

Kinetic modeling of anhydrous proton conduction in side chain liquid crystal polyacrylates

Mesomorphic polyacrylates with different degree of sulfonation (DS) in side chains were synthesized by post polymerization functionalization. The sulfonated polymer exhibited thermotropic smectic A (SA) and/or nematic (N) phases when DS was 0.2–0.4. The temperature-dependent anhydrous proton conductivities of the polymers depended on both ion exchange capacity (IEC) and phase type. A modified Arrhenius equation containing IEC and phase coefficient M simultaneously was proposed to model the conduction behavior. Least-squares regression analysis on the kinetic parameters quantitatively revealed proton conduction characteristics in different liquid crystal phases. The activation energies for proton transportation in the SA, N, and isotropic states were 106, 95 and 44 kJ mol−1, respectively. The inherent conductivities per unit IEC in the SA, N, and isotropic states were 8.5 × 108, 5.3 × 107 and 77 S cm−1, respectively. The enhancement of anhydrous proton conduction in liquid crystal phases was ascribed to the increased conducting pathways induced by ordered molecular arrangements.

Elucidating the sorption mechanism of “mixed-mode” SPME using the basic drug amphetamine as a model compound

We studied the sorption of amphetamine as a model drug to represent small, polar organic cations to a new SPME coating combining C18 and propylsulfonic acid. This combination of hydrophobic and strong cation exchange (SCX) groups was compared to conventional SPME fibers with polyacrylate (PA) or C18 coating. The affinity of amphetamine at physiological pH (PBS) was 20 to 180 times greater for the new C18/SCX coating than for C18 alone and PA of different coating thickness. As amphetamine is a base and >99% protonated at physiological pH, this enhanced affinity is attributed to the ion-exchange phase in the coating. Tests at pH above the pKa of amphetamine show that, when normalized to the coating volume, neutral amphetamine also has a higher affinity compared to PA. As ion-exchange groups are not unlimitedly present in the coating, amphetamine isotherms level off to a saturation concentration on the C18/SCX fiber at the highest tested aqueous concentrations. Also, other cations (Na+, K+, Ca2+) compete for the SCX sites and decrease the sorption coefficients, e.g. by 1.7log units when comparing Milli-Q water with PBS. The C18/SCX fiber provides improved sensitivity over some of the classic SPME fibers. However, care should be taken near the cation exchange capacity of the fiber and the fiber should be calibrated in an appropriate matrix so as to eliminate competition effects.

Separation performance of vancomycin-bonded stationary phase

Vancomycin is one of the macrocyclic antibiotics with complex molecular structure. Based on the various functional groups of vancomycin, a vancomycin-bonded stationary phase using glutaraldehyde as the spacer was prepared. Its chromatographic properties in reversed-phase, ion exchange and hydrophilic phase modes were investigated separately. The prepared stationary phase showed the typical characteristic of the reversed-phase stationary, when the organic solvent content was low in the mobile phase. On the contrary, its chromatographic characteristic transformed into hydrophilic phase mode with the organic solvent content increased in the mobile phase. Owing to the amino groups of vancomycin, ion exchange mode can also be applied to the separation method development. The vancomycin-bonded stationary phase was applied to the separation of eight achiral drugs and stevioside in reversed-phase, ion exchange and hydrophilic phase modes. The separations were achieved in three different kinds of separation modes by using appropriate chromatographic conditions. The results provide guidance for the design of new types of stationary phase, and method development of chromatographic stationary phases modified by special compounds with complex construction in corresponding separation modes.

Multimodal liquid chromatography of small molecules

Multimodal chromatography (MMC) is a family of chromatographic techniques that has been used when single separation modes fail. Multimodal liquid chromatography (MMLC) is a special type of MMC that is applied to increase the number of compounds that can be separated in a single run and to widen the applicability of LC methods. Employment of various modes for chromatographic separations is possible by utilizing different stationary phases, different mobile phases, or different chromatographic conditions in the same run. The selected stationary phases represent the most important variable in MMLC systems. These stationary phases can be classified as mixed or discrete where the former can be either homogeneous or heterogeneous in nature, and the latter can be either tandem or biphasic. Common examples are ion exchange phases with hydrophobic or hydrophilic linkages. Choosing the right mobile phase depends on the compatibility with the recruited modes. A sequential pH and organic solvent gradient is effective for a mixture of charged and neutral compounds. The contributing modes in MMLC can be determined by changing the stationary phase, changing the mobile phase variables, investigating the retention order or comparing the retention patterns to those obtained by single mode methods. The different applications of MMLC in medical, pharmaceutical, and industrial analysis of small molecules are discussed. Representative sample mixtures are water soluble/fat soluble vitamins, acidic/neutral aromatics, and inorganic anions/cations. A table that summarizes the separation modes, the employed stationary phases, the mobile phases, and the detection methods is provided.

Influence of Surface Acidity of Y Zeolites on the Adsorption of Organic Molecules by <em>In situ</em> Fourier Transform Infrared Spectroscopy

The surface acidity of Y-type zeolites (HY and NaY) modified by solid state ion exchange (SSIE) and liquid phase ion exchange were characterized by in situ Fourier transform infrared (FTIR) spectroscopy using pyridine as the probe molecule (Py-FTIR). The adsorption of single probe molecules (thiophene, cyclohexene and benzene) and double probe molecules (thiophene and cyclohexene, thiophene and benzene) compared with sorbents were studied using in situ FTIR spectroscopy. The results indicated that the Bronsted acid (B acid) of HY (L-CeY) is the catalytic center of cyclohexene dimerized alkenyl carbenium ions and thiophene oligomerization, while the Lewis acid (L acid) is the major center of adsorption of thiophene, cyclohexene, and benzene. In addition, there is strong chemisorption and competitive adsorption of cyclohexene and thiophene, which provides evidence for the poor performance [Article] doi: 10.3866/PKU.WHXB201303183 www.whxb.pku.edu.cn 物理化学学报(Wuli Huaxue Xuebao) Acta Phys. -Chim. Sin. 2013, 29 (6), 1273-1280 June Received: January 2, 2013; Revised: March 18, 2013; Published on Web: March 18, 2013. ∗Corresponding author. Email: lsong56@263.net; Tel/Fax: +86-24-56860658. The project was supported by the National Natural Science Foundation of China (20976077, 21076100), Major Program of Petroleum Refining of Catalyst of Petro China Company Limited (10-01A-01-01-01), Innovation Team of Liaoning Province Colleges, China (200T110), and Construction Project of Liaoning Province High-end Talent Team. 国家自然科学基金(20976077, 21076100),中国石油天然气股份有限公司炼油催化剂重大专项(10-01A-01-01-01),辽宁省高校创新团队项目 (200T110)及辽宁省高端人才队伍建设项目资助 C Editorial office of Acta Physico-Chimica Sinica 1273 Vol.29 Acta Phys. -Chim. Sin. 2013 of removing sulfur. The S-CeY zeolite has abundant of weak Lewis acid sites. The sorbent is good at absorbing thiophene, while the influence of the competition adsorption of cyclohexene was not predominately. As to NaY zeolite, there is no preference for adsorption of thiophene, cyclohexene and benzene.

Simultaneous determination of four β2-agonist residues in pig feed and urine by capillary electrophoresis with field amplified sample injection and electrochemiluminescent detection

A novel method for simultaneous determination of clenbuterol (CLB), terbutaline (TER), salbutamol (SAL), and procaterol (PRO) was proposed based on capillary electrophoretic (CE) separation and electrochemiluminescent (ECL) detection. Matrix solid phase dispersion (MSPD) and ion exchange coupled with mesoporous nanocarbon adsorption were adopted to pretreat solid and aqueous samples, respectively. The sensitivity was enhanced by about 9-fold due to the online stacking via field amplified sample injection. The conditions for CE separation and ECL detection were investigated in detail. The four β2-agonists were baseline separated under the optimum conditions within 10 min. The linear ranges were 0.25–10.00 μmol L−1 with detection limits (S/N = 3) of 0.081, 0.076 and 0.034 μmol L−1 for CLB, TER and SAL, respectively, and 0.5–20.00 μmol L−1 for PRO with a detection limit of 0.12 μmol L−1. The developed method was successfully applied to determine the four β2-agonists in real samples, offering average recoveries ranging from 88.9% to 107.1% for pig feed, and from 86.7% to 109.1% for pig urine.

Transport Characteristics of Aromatic Acids in the Capillary Electrochromatography with Mixed Magnetic Nanoparticles Coating as Stationary Phase

In this paper, novel open-tubular electrochromatographic system with core/shell magnetic nanoparticles modified by amino and C18 functional groups as mixed stationary phase by using a series of permanent magnets to immobilize nanoparticles into the capillary were investigated. The new system showed high separation ability and efficiency due to high specific surface area of nanomaterial and mixing separation mechanism. The transport equations of aromatic acids using the open-tubular electrochromatographic column with magnetic nanoparticle coating as stationary phases were derived under isocratic and double stepwise gradient elutions, and the retention characteristics of organic acids separated by the columns were further investigated. The results showed that the electroosmotic flow gradually decreased with the increase of Fe3O4@SiO2-NH2 in the mixed stationary phases, and the direction of electroosmotic flow reversed eventually. The capacity factor was relevant to the ratio of ion-exchange and reversed-phase stationary phases. Furthermore, experiments confirmed that the capacity factor of solute had a good linear relationship with the ratio of mixed stationary phases, and the correlation coefficient was greater than 0.9166 after fitting. Under the double stepwise gradient elution condition, the migration time of solute can be predicted by its elution time under isocratic elution. After the solutes were eluted by phosphate buffer stepwise gradient elution, the relative errors between predicted retention time and actual retention time of solute were less than 8.0%. After they were eluted by organic modifier concentration stepwise gradient elution, the relative errors between two values of solute were less than 10%. After they were eluted by pH value stepwise gradient elution, the relative errors between two val- ues of solute were less than 5.8%. Rhizoma gastrodiae was separated by the constructed system under the optimized chroma- tographic condition, the main components of gastrodin, vanilla alcohol and citric acid were identified based on retention time of standards, and the relative errors between predicted value and actual value of citric acid was 11%. The open-tubular elec- trochromatographic system shows great potential in the method development of analysis of complicated samples. Keywords gradient elution; transport characteristic; mixed stationary phase 1 引言

GEM-SELEKTOR GEOCHEMICAL MODELING PACKAGE: TSolMod LIBRARY AND DATA INTERFACE FOR MULTICOMPONENT PHASE MODELS

The development of highly accurate and computationally efficient modeling software based on Gibbs energy minimization (GEM) makes it possible to thermodynamically simulate geochemically realistic subsurface fluid-rock interaction processes. This involves consideration of non-ideal multicomponent-multiphase systems that include dilute to concentrated aqueous electrolyte solutions, mineral solid solutions, supercritical fluids, silicate and metal melts, and sorption and ion exchange phases. Predicting the stability and thermodynamic properties of non-ideal solution phases over wide ranges of pressures and temperatures requires that theoretically sound and sufficiently accurate equation of state and activity models are used within the GEM framework. The variety of such models calls for a novel, flexible, and computationally efficient code architecture that supports a wide range of models of non-ideal mixing with different mathematical structures and input data. Here, we introduce the TSolMod C++ class library for equation of state and activity models, implemented within the GEMS3K solver of geochemical equilibria as part of the GEM-Selektor code package (http://gems.web.psi.ch). Essential features of the TSolMod library include a generic and flexible model parameter setup, computationally efficient data exchange with the GEM algorithm, and a straightforward extensibility with any new models of mixing. The current version of TSolMod features a comprehensive selection of fluid, gas, liquid, and solid solution models of interest for geochemical, petrological, material science, and chemical engineering applications.

Studies in River’s Bottom Sediments in Swarnarekha River around Jamshedpur and Ghatsila for Metallic Pollution

Studies of heavy metals namely Iron, Chromium, Manganese, Cobalt, Nickel, Copper, Zinc, Cadmium and lead as pollutants in river water and waste water discharge samples of rivers around steel plants of Jamshedpur and Ghatsila, East Singhbhum, Jharkhand, was carried out from February,2012 to March, 2012. Atomic Absorption spectrophotometric analysis of nonfilterable residue of bottom sediments for the heavy metals were made. The fractionation analysis of the adsorption and/or ion exchangeable, oxide coating, organic solids and crystalline phase was carried out. Total metals concentration was also determined. The sum of the concentration of metals in adsorbed, oxide coating and organic solid phases is available to biota. The crystalline phase is not available to biota. The results have been discussed and the conservation of metal available to biota have been estimated.

Novel haemoglobin mutation (α127Lys → Glu) increases oxygen affinity and has a minor effect on haptoglobin binding

ObjectivesTo determine if a new haemoglobin (Hb) variant was the underlying cause of erythrocytosis in a subject with a high apparent HbA1c. Design and methodHaemolysate was analysed by ESI MS, and individual components purified by ion exchange and reverse phase chromatography. Peptide mapping was used to pinpoint the substitution and DNA sequencing to confirm the precise mutation. Oxygen affinity was measured and relative haptoglobin (Hp) binding estimated. ResultsIntact protein analysis and peptide mapping suggested a mutation in peptide α13 and DNA sequencing confirmed a novel α127Lys→Glu substitution in the α 2 gene. The abnormal Hb had a significantly higher O2 affinity (5.8mmHg) than HbA (12.4mmHg). In addition the mutation caused a small but significant decrease in Hp binding. ConclusionMolecular models show that the side chain of α127Lys stabilises the T structure of deoxy Hb and that mutation to Glu would favour conversion to the high affinity R state. Notwithstanding this and the demonstrated high affinity, there was only a small increase in RBCs, Hb concentration and PCV in other female carriers of the mutation. The absence of a significant phenotype of erythrocytosis is most probably due to the low level (19%) of the variant.

Using InCl vapor to ion exchange indium into zeolite Na–X. II: A single crystal structure containing (In8Cl8)16+, In57+–Cl−–In57+, and In+

Anhydrous vapor phase ion exchange (VPIE) using InCl(g) had been used to introduce indium ions into zeolite Na92–X (FAU, Si/Al=1.09); the product was In14+(In57+)4Na50+–X. Treatment of Na92–X with a lower vapor pressure of InCl(g) at lower temperatures has now yielded In6.4+(In8Cl8)1.7316+(In10Cl)1.013+Na45.6+–X; Cl− ions were retained and cationic InnClmp+ clusters have formed. Its structure was determined using single-crystal crystallography with synchrotron X-radiation and was refined in the space group Fd3¯ (a=24.890(1)Å) to the final error index R1=0.066. In8Cl816+ clusters center and extend out of 22% of the sodalite cavities. Each consists of a tetrahedrally distorted In4Cl4 cube (In–Cl=2.323(23)Å) with –In–Cl extending radially from each of its Cl− ions (the Cl–In–Cl distances are 2.302(17) and 2.406(14)Å, respectively). With Cl− ions and oxygen atoms of the zeolite framework, these indium ions, all In3+, have octahedral and trigonal bipyramidal coordination, respectively. In57+ cationic clusters center another 25% of the sodalite cavities. In57+ is a centered tetrahedron with In–In=2.745(8)Å; each terminal atom bonds to three framework oxygen atoms of a double 6-ring with In–O=2.150(5)Å and O–In–O=105.1(3)°. One terminal atom of each In57+ cluster also bonds to a Cl− ion at site I, which in turn bonds linearly to a terminal atom of another In57+ cluster. In this way the In57+ units link together in pairs to give In10Cl13+. The remaining indium cations, 6.4 In+ per unit cell, are in the sodalite cavities. Most of the Na+ ions, 25.1 per unit cell, complete the filling of the single 6-rings; the remainder are at 12-ring sites.

Optimized analysis and quantification of glucosinolates from Camelina sativa seeds by reverse-phase liquid chromatography

Gold-of-pleasure or false flax (Camelina sativa L. Crantz) is being developed as an alternative oil crop for biodiesel and for food use. The seed meal, which contains three relatively unique glucosinolates, is being evaluated for approval for use as an ingredient in animal feeds and for other uses. The objective of this research was to develop reproducible methods for the isolation of large quantities of pure camelina glucosinolates (glucoarabin, glucocamelinin, and 11-(methylsulfinyl)-undecylglucosinolate) and develop efficient methods for quantifying these compounds. The separation and purification of the camelina glucosinolates were achieved using a combination of reverse phase chromatography, counter-current chromatography and ion exchange chromatography. An efficient reverse phase HPLC separation method was used to quantitate the glucosinolate content in camelina seed and plant extracts. The quantitation methodology was used to measure glucosinolate levels in seeds from 30 cultivars grown in a U.S. field trial and measure glucosinolates levels in sprouted camelina seeds.

Synthesis of lithium-beta-alumina by various ion-exchange and conversion processes

Various methods for the synthesis of lithium-beta-alumina solid ion conductors were studied. The starting material was a composite of α-Al2O3 and YSZ for which the fabrication process is well established. The α-Al2O3/YSZ composite was vapor-assist converted into a water-stable Na-beta″-alumina composite structure and then ion-exchanged in either liquid or vapor phases. An attempt was also made to convert the α-Al2O3/YSZ composite directly into a Li-beta structure. Na-β″-alumina was ion-exchanged successfully in both liquid and vapor phases to form Li-β″-alumina or LiyNa1−y-β″-alumina. The liquid phase ion-exchange of Na+ by Li+ in chloride at 700°C resulted in mechanically stable Li-beta″-alumina with 60% conversion of Na. The vapor-assist ion-exchange method was more effective, yielding a higher conversion (90%) of Na. Despite the perception that Li ions are mostly intercalated into the spinel blocks preventing the formation of stable Li-beta phases, the stable beta-alumina structure was confirmed by XRD analysis after the high-temperature (1450°C) vapor-assist ion-exchange of Na+ by Li+ in the LiO powder-packed bed. A conductivity of 7×10−5S/cm at 20°C was obtained by extrapolation of the vapor-assist ion-exchanged sample data. The vapor phase equilibrium of the LiO phases is quite different from the NaO phases, and there seems to be an opportunity of enhanced conductivity by optimizing the vapor-assist process. While the vapor-assist ion-exchange of Na-beta-alumina shows a promising route for the synthesis of stable Li-beta-alumina ion conductors, the direct vapor-assist conversion from alpha to beta led to the formation of the LiAl5O8 spinel phase.