Uranium leaching using mixed organic acids produced by Aspergillus niger

Source term information is required for to reconstruct a device used in a dispersed radiological dispersal device. Simulating a radioactive environment to train and exercise sampling and sample characterization methods with suitable sample materials is a continued challenge. The Idaho National Laboratory has developed and permitted a radioactive response training range (RRTR), an 800 acre test range that is approved for open air dispersal of activated KBr, for training first responders in the entry and exit from radioactively contaminated areas, and testing protocols for environmental sampling and field characterization. Members from the Department of Defense, Law Enforcement, and the Department of Energy participated in the first contamination exercise that was conducted at the RRTR in the July 2011. The range was contaminated using a short lived radioactive ⁸²Br isotope (activated KBr). Soil samples contaminated with KBr (dispersed as a solution) and glass particles containing activated potassium bromide that emulated dispersed radioactive materials (such as ceramic-based sealed source materials) were collected to assess environmental sampling and characterization techniques. This presentation summarizes the performance of a radioactive materials surrogate for use as a training aide for nuclear forensics.     

Universal solid-phase approach for the immobilization, derivatization, and resin-to-resin transfer reactions of boronic acids.

Boronic acid-containing molecules are employed in a broad range of biological, medicinal, and synthetic applications. These compounds, however, tend to be difficult to handle by solution-phase methods. Herein, this problem is addressed with the development of the first general solid-phase approach for the derivatization of functionalized boronic acids. This approach is based on the use of a diethanolamine resin anchor that facilitates boronic acid immobilization by avoiding the need for exhaustive removal of water in the esterification process. The immobilization of a wide variety of boronic acids onto N,N-diethanolaminomethyl polystyrene (DEAM-PS, 1) can be performed within minutes by simple stirring in anhydrous solvents at room temperature. Evidence for the formation of a bicyclic diethanolamine boronate with putative N-B coordination was shown by (1)H NMR analysis of DEAM-PS-supported p-tolylboronic acid. The hydrolytic cleavage of the same model boronic acid from the DEAM-PS resin was studied by UV spectroscopy. Hydrolysis and attachment were shown to occur under a rapidly attained equilibrium, and a large excess of water (>32 equiv) is required to effect a practically quantitative release of boronic acids from DEAM-PS. Despite their relative sensitivity to water and alcohols, DEAM-PS-bound arylboronic acids functionalized with a formyl, a bromomethyl, a carboxyl, or an amino group can be transformed in good to excellent yields into a wide variety of amines, amides, anilides, and ureas, respectively. Ugi multicomponent reactions on DEAM-PS-supported aminobenzeneboronic acids, derivatization of multifunctional arylboronic acids, and sequential reactions can also be carried out efficiently. These new DEAM-PS-supported arylboronic acids can be employed directly into resin-to-resin transfer reactions (RRTR). This type of multiresin process helps eliminate time-consuming cleavage and transfer operations, thereby considerably simplifying the outlook of combinatorial library synthesis by manual or automated means. This concept was illustrated by a set of optimized procedures for the Suzuki cross-coupling and the borono-Mannich reactions.     

Development of resin-to-resin transfer reactions (RRTR) using Sonogashira chemistry

Sonogashira chemistry can be used according to the ‘resin-to-resin transfer reaction’ (RRTR) concept. Two fragments, one containing the halide moiety and the second one incorporating the alkyne functionality, are anchored on different solid supports using allyl and/or Wang-type linkages. Treatment with Pd(0) cleaves the allyl-linked fragment(s) which subsequently undergo Sonogashira coupling under the same conditions.     

Synthesis of bifunctional peptide derivatives based on a β-cyclodextrin core with drug delivery potential

A selective, versatile, robust methodology for bifunctionalization of β-cyclodextrin is achieved allowing the attachment of peptides in varying C- and/or N-terminal combinations on resin using Fmoc SPPS. Two linkers are attached to cyclodextrin enabling selective binding to the resin (or a peptide attached to the resin). Continuation of peptide growth and/or cleavage from the resin follows, thus various combinations of peptide-cyclodextrin species are achieved. A model peptide (Gly-Ala) is used in this study to illustrate the potential of this system for attaching one or more bioactive peptides for drug transport and release purposes.     

The Rate Problem of a Thermally Regenerable Ion-Exchange System

Earlier equilibrium studies have established the thermal dependence of the equilibrium between salt solution and a mixed bed of weakly basic and weakly acidic ion-exchange resins. High resin utilization can be achieved if the resin properties and equilibrium conditions are optimized; the equilibrium characteristics of polyacrylic acid and polyvinylbenzyldiethylamine resins are quite suited for the practical desalination of brackish waters.

However, the adsorption rates exhibited by normal-sized resin beads of this type are much too slow for satisfactory operation of the process because of the low concentration of protons available for transfer between the resins. It is shown that increasing the porosity of the resins improves amine resin kinetics 10-fold and carboxylic acid resin kinetics 6-fold. Nevertheless such improvements are still inadequate for practical purposes, and it is concluded that for satisfactory rates to be achieved systems having much shorter diffusion paths are necessary.

Two further approaches to the rate problem are discussed, both involving the synthesis of novel resin systems. A mixed bed of microbeads (10-20 p) reacts at acceptable rates but presents mechanical problems; the magnetic flocculation of finely divided magnetic resins is reported as one possible solution to this problem. Another avenue is the synthesis of normal-sized beads of the amphoteric and snake-cage variety. Resins of this type that exchange at suitable rates are described.     

苯乙烯和丙烯酸系改性醇酸树脂涂料

综述了苯乙烯和丙烯酸系改性醇酸树脂的研究进展,介绍了该类树脂的合成、性能及应用,讨论了该类树脂的优缺点,预测了苯乙烯和丙烯酸系改性醇酸树脂涂料的发展趋势。     

Analytical tools for monitoring changes in physical and chemical properties of chromatography resin upon reuse

Protein A resins are often reused for multiple cycles to improve process economy during mAb purification. Significant reduction in binding capacity and product recovery are typically observed due to the presence of unwanted materials (foulants) deposited on the resin upon reuse. In this paper, we have used a wide spectrum of qualitative and quantitative analytical tools (particle size analysis, HPLC, fluorescence, SEM, MS, and FTIR) to compare the strengths and shortcomings of different analytical tools in terms of their capability to detect the fouling of the resin and relate it to chromatographic cycle performance. While each tool offers an insight into this complex phenomena, fluorescence is the only one that can be used for real‐time monitoring of resin fouling. A correlation could be established between fluorescence intensity and the process performance attributes (like yield or binding capacity) impacted upon resin reuse. This demonstration of the application of fluorescence for real‐time monitoring correlated empirically with process performance attributes and the results support its use as a PAT tool as part of a process control strategy. While the focus of this paper is on fouling of protein A chromatography resin, the approach and strategy are pertinent to other modes of chromatography as well.     

化学改性环氧树脂水基涂料的研究——涂膜性能

用对氨基苯甲酸改性环氧树脂 ,使其具有亲水亲油两亲性质 ,测定了改性产物和纯环氧树脂共混物的玻璃化转变温度 ,结果显示两者能够相容 ,并以改性产物及其与纯环氧树脂的混合物制备水基涂料 ,测定了涂膜的物理和化学性能。结果表明 ,涂膜性能优良 ,保持了溶剂型环氧涂料的抗冲击强度、光泽度和硬度等方面的优点 ,而附着力提高 ,同时柔韧性大为改善 ,涂膜耐水性和耐化学药品性能优良。     

Preparation of polymer-bound pyrazolone active esters for combinatorial chemistry

The preparation of solid-phase active esters from a new pyrazolone linker resin is described. N-Acylation using this resin provides various amide products with a high conversion rate and good purity under mild conditions. The polymer-bound pyrazolone linkers are stable in the reaction conditions and are resistant to hydrolysis. Moreover, this resin can also be reused repeatedly without a loss of reactivity.     

Preparation of Designer Resins via Living Free Radical Polymerization of Functional Monomers on Solid Support

Merrifield resin is converted to a solid-supported free radical initiator by reacting with the TEMPO-Na. Heating TEMPO-methyl resin with a variety of functionalized styrene and acrylate monomers gives larger resin beads via living free radical polymerization. We have coined the term Rasta resin to describe resin beads prepared in this fashion. The process can be described as a solvent-free suspension polymerization. It is particularly well suited for preparation of resin beads from monomers which contain electrophilic groups that would be destroyed upon suspension polymerization in water. Rasta resins have a novel macromolecular architecture wherein long straight chain polymers bearing reactive functional groups emanate from the phenyl groups of a cross-linked polystyrene core. With judicious choice of co-monomers and polymerization strategy, the solvent affinity, loading capacity, and distance of functionality from the cross-linked core may be controlled giving beads with properties that are tailored to specific uses as synthesis supports and scavenging resins.     

Cure monitoring of CFRP composites by dynamic mechanical analyser

The cure characteristics of carbon/MTM44-1 epoxy composite prepreg and neat MTM44-1 epoxy resin are monitored using a dynamic mechanical analyser (DMA). This study also assesses whether the simple containment device recommended by the DMA manufacturer for powder and gel is suitable for prepregs. The device is a disposable 0.1-mm thick stainless steel pocket. The cure behaviour of the packaged materials is compared with that of the unpackaged prepreg. All the samples are cured following the manufacturer's 180°C-isothermal schedule with heating rates of 2 °C/min and 5 °C/min. The tests highlight that: (i) the cure of composite prepregs and resin can be monitored using a DMA; (ii) the stainless steel pocket does not influence the cure of the prepreg and resin; and (iii) the softening and melting of the uncured resin, the resin low viscosity state and the subsequent gelation-vitrification-solidification of the resin are detected with this method.     

Preparation and Analytical Application of a New Chelating Ion Exchange Resin Containing Thioglycolic Acid

Starting from copolymerization of acrylonitrile and divinylbenzene by emulsion polymerization technique, a macroporous, crosslinked polyacrylonitrile copolymer was synthesized. The nitrile groups on the copolymer resin were converted into carboxylic acid groups by hydrolysis with strong alkaline solution of sodium hydroxide to obtain the resin matrix with carboxylic acid groups. A new chelating ion exchange resin containing alkylthioglycolate was prepared by esterification of carboxylic acid groups on the resin matrix and thioglycolic acid with 1,6-hexanediol as binding part. After studies of the basic characters, ion exchange ability, exchange rate and acidity of the medium, it was found that the new resin obtaind was highly selective for silver(I), mercury(II), gold(III) and bismuth(III) in acidic-aqueous solution. Separation of these metal ions from each other and concentration of these metal ions from very dilute solution were studied by liquid chromatography using a short column of this new resin. The analytical applications of this new resin are reported.     

A comparison of preconcentration reagents for flow injection analysis flame atomic spectrometry

A small range of new commercially available chelating resins are compared with a resin prepared in-house in terms of their applicability for on-line preconcentration and matrix separation. The flow injection manifold was designed for rapid matrix separation and the resins were tested for the determination of Cull, ZnII, CdII, MnII and NiII. The resin based on controlled pore glass was found to be better for this rapid procedure because it did not require conditioning, although the polymer based resins had better capacities. The commercially available controlled pore glass based iminodiacetate (IDA) resin had a comparable performance to the in-house controlled pore glass 8-hydroxyquinoline (CPG-8-HQ) resin. The IDA resin had a much higher capacity than the 8-HQ, however as with all IDA based resins, some retention of Call was observed. The sample throughput was 12 h⁻¹.     

Solid Phase Synthesis. Evidence for and Quantification of Intra res in Reactions

Abstract

Intrareaction occurs between moieties attached to copolystyrene-2% divinylbenzene resin as used in solid phase synthesis even when only 0.5% of the phenyl residues are functionalized. Evidence for this interaction has been obtained from the dimeric products resulting from Dieckmann cyclization of resin bound sebacates and ω-cyanopelargonyl thiol resin esters, from kinetic and product data on radioactivity scrambling during the Dieckmann cyclization of uniquely singly labeled tertiary alkyl pimeloyl resin esters, and from anhydride formation with carboxymethyl resin. The extent to which site-site interactions can occur as a function of the percentage functionalization has been measured quantitatively by radiotracer studies on intraresin anhydride formation from carboxymethyl substituted resin. The synthesis and characterization of the resin bound re-actants is described, and the significance of these observations is discussed.     

Determination of iron and copper in seawater at pH 1.7 with a new commercially available chelating resin, NTA Superflow

The use of a commercially available chelating resin with NTA-type functional groups for concentration of trace metals from seawater is described. Trace metal recoveries from this NTA Superflow chelating resin are pH dependent. At a pH of ≤2 only iron(III) and copper are quantitatively recovered from the resin. Iron(II) cannot be quantitatively recovered from this resin below a pH of 5. However, oxidation of acidified seawater samples (pH 1.7) with H₂O₂ prior to loading onto the resin has been demonstrated to allow quantitative recovery of total dissolved iron. Deferrioxamine and Rhodoturlic Acid, two commercially available siderophores were used to investigate the effect of strong Fe(III)-binding organic ligands on the ability to retain iron at different pH values. Acidification of seawater samples to pH 1.7 dissociates the iron complexed to these organic ligands, thereby allowing total dissolved iron and copper to be determined. Acidified samples from Monterey Bay were analyzed by a flow injection method coupled to ICP-SFMS detection using the NTA Superflow resin in the pre-concentration step. Results from this study show that when seawater samples are stored acidified (pH 1.7) over time, a portion of iron(III) is reduced to iron(II), thus necessitating the use of H₂O₂ to reoxidize the Fe(II) to Fe(III) prior to analysis. Total dissolved concentrations of iron and copper can be directly obtained on seawater samples at pH 1.7 with this method, eliminating the need to buffer the sample to a higher pH prior to column loading. This resin has the potential to be used in shipboard or in situ flow injection methods.     

茜素红S螯合树脂分离富集测定地质样品中的痕量金、铂和钯

用螯合树脂对金属进行分离富集及测定,前人已做了许多有意义的研究^[1～4].曾用含键合S双硫腙(P-D)和脱氢双硫腙(P-DT)功能团的离子交换树脂和螯合树脂分离金和铂族金属^[5],用双硫腙负载树脂分离富集Cu(Ⅱ)^[6]。     

Re-assessment of chelating ion-exchange resins for trace metal analysis of sea water

The behaviour of the chelating ion-exchange resin Chelex-100 for collection of trace metals from sea water has been studied by anodic stripping voltammetry after acid digestion of the sea water sample and the resin effluent. All the naturally occurring, electrochemically reducible species of Cu, Pb, Cd and Zn are chelated by the resin; this fraction of these metals is regarded as the dissolved fraction. Centrifugation showed that some of the metal liberated by acid digestion is associated with colloidal species. Neither this nor the metal adsorbed on fine particles is affected or removed by the chelating resin.     

CMC-Na/DETA-B62型蛇笼树脂对金属离子的吸附性能

本文研究了自合成的蛇笼型螯合树脂-二乙烯三胺交联甘油环氧树脂/羰甲基纤维素体系对Cd^2 ,Pb^2 ,Fe^2 的吸附量，吸附动力学，等温吸附过程等静态吸附性能，同时研究了pH值等因素对吸附性能的影响。实验结果表明，该树脂对Cd^2 具有较强的吸附选择性，能在Cd^2 ,Pb^2 ,Fe^2 3种离子共存时选择吸附Cd^2 ，其选择性系数分别为Kcd^2 /pb^2 =3.77,Kcd^2 /Fe^2 =9.61。该树脂对上述3种离子的吸附量可分别达4.00,1.06,0.42mmol/g。该类树脂可用于含重金属离子污水的处理和金属离子的分离等方面。     

A procedure for sampling and analysis of air for energetics and related compounds

A procedure for the sampling and analysis of energetics and related compounds in the atmosphere is described. The basic procedure consists of the collection of air samples using sampling cartridges containing XAD-2 resin, extraction of the resin with isoamyl acetate, and an analysis of the extract using gas chromatography with electron capture detection. Modifications and additions to this procedure are discussed, such as the use of a prefilter before the resin sampler to collect particulates and the use of a mass selective detector to analyze for some propellant compounds of interest or for quantitative confirmation purposes. Two differing sizes of samplers are evaluated according to the air volumes required for collection. The procedure is tested through the analysis of spiked resin samples, which had air pulled through them for periods of time corresponding with the required sampling volumes. This procedure has application toward the measurement of energetic residues in atmospheres resulting from weapons testing and operations during training exercises involving munitions.