Crown Ether Resin Research Articles

Fast analysis method of strontium-90 after separation using crown ether resin

ObjectiveTo explore the separation condition for 90Sr using crown ether resin, in order to establish a fast method for analysis of 90Sr in food and environmental samples. MethodsStable strontium isotope (88Sr) was used to simulate the radioactive 90Sr, and the concentration of 88Sr in elution solution was detected using inductively coupled plasma mass spectrometry (ICP–MS). The separation conditions were investigated through batch experiment. ResultsUnder the optimized experimental conditions, the maximum adsorption capacity of crown ether resin was 22.28 ​mg/g. 4.0–8.0 ​mol/L nitric acid made it easier for the Sr2+ to load on the resin, and 20 ​mL ultrapure water was used to rinse the chromatographic column to achieve a good separation effect, by which the recoveries of Sr2+ were nearly close to 100%. The average recovery rates of 4 samples were 60.25%, 69.26%, 75.09% and 66.33%, respectively. ConclusionsCrown ether resin has very good selectivity and adsorption for 90Sr. The optimized conditions were high-efficiency and easy to operate. The separation method has great potential for the fast analysis of 90Sr in food and environmental samples.

Calcium isotope separation by band chromatography using 18-crown-6-ether resin

ABSTRACT To develop the 48Ca enrichment process, a feasibility study on a band chromatography was made using 9 M HCl solution and crown ether resin synthesized in porous silica beads. Prior to the chromatographic experiments, distribution coefficients, Kd, of Ca2+ and Sr2+ were measured at different concentrations of these ionic species. The frontal boundary of the chromatography was made by a usual manner of the breakthrough mode of calcium feeding, and the rear boundary was made by introducing strontium as a following ion on the basis of the observed Kd values. It was confirmed that the heavy isotope 48Ca was depleted in the rear boundary region, while 48Ca was enriched in the front boundary region. The values of separation coefficient ε (= α – 1) in three chromatographic operations at different temperatures were observed as 2 × 10−3 ~ 3 × 10−3. The separation coefficients observed in the front boundary regions, where 48Ca was enriched, agreed with those observed in the rear boundary regions, where 40Ca was enriched.

Selective Lithium Recovery from Seawater Using Crown Ether Resins

Selective Lithium Recovery from Seawater Using Crown Ether Resins

Molecular engineering of functionalized crown ether resins for the isotopic enrichment of gadolinium: from computer to column chromatography

Computer aided molecular engineering of functionalized crown ethers for isotope separation of gadolinium using column chromatography.

クラウンエーテル樹脂を用いた液体クロマトグラフィーによるカルシウム同位体分離 ーモノベンゾ-18-クラウ ン-6-エーテル樹脂とジベンゾ-18-クラウン-6-エーテル樹脂の比較ー

クラウンエーテル樹脂を用いた液体クロマトグラフィーによるカルシウム同位体分離 ーモノベンゾ-18-クラウ ン-6-エーテル樹脂とジベンゾ-18-クラウン-6-エーテル樹脂の比較ー

Calcium isotope fractionation in liquid chromatography with crown ether resin in methanol medium

Breakthrough mode liquid chromatography was employed to investigate calcium (Ca) isotope fractionation in methanol medium. Highly porous silica beads, the inner pores of which were embedded with a benzo-18-crown-6 ether resin, were used as column packing material. Enrichment of heavier isotopes of Ca was observed in the frontal part of the respective Ca chromatograms. The values of the isotope fractionation coefficient (ϵ) were in the order of 10−3 at 25 °C. Use of methanol as solvent has little advantage over the aqueous system as far as the values of ϵ are concerned. However, a substantial improvement was observed concerning the adsorption capacity of the crown ether resin for Ca ions. Molecular orbital calculations supported the present isotopic results in a qualitative fashion.

Calcium isotope fractionation in liquid chromatography with crown ether resins

Breakthrough mode liquid chromatography was employed to study calcium isotope fractionation. Highly porous silica beads, the inner pores of which were embedded with a benzo-18-crown-6 ether resin or a benzo-15-crown-5 ether resin, were used as column packing material. For both the resins, enrichment of heavier isotopes of calcium was observed in the frontal part of their respective calcium chromatograms. The values of the isotope fractionation coefficient were on the order of 10−3 and 10−4 for the benzo-18-crown-6 ether and benzo-15-crown-5 ether resins, respectively. The observed isotope fractionation coefficient was dependent on the concentration of hydrochloric acid in the calcium feed solution; a higher hydrochloric acid concentration resulted in a smaller fractionation coefficient value. The present calcium isotope effects were most probably mass dependent, indicating they came from isotope effects based on molecular vibration. Molecular orbital calculations supported the present experimental results in a qualitative fashion.

Lithium isotope separation with displacement chromatography using crown ether resin immobilized on porous silica beads

A crown ether resin immobilized on porous silica beads was investigated as a chromatographic packing for lithium isotope separation by displacement chromatography. In order to develop an effective chromatographic packing, effects of the diameter of the packing particle on the transport phenomena in the particle were investigated by numerical simulation. Transient change of the concentration profiles in the both solution phase and resin phase were obtained and lithium-6 enrichment in the resin phase was well simulated. A dimensionless coefficient, which represents a ratio of the diffusive mass transfer rate to the adsorption rate, was found in the mass balance equation. The magnitude of the factor was also evaluated for various values of diameter of the packing particle.

Mass dependence of calcium isotope fractionations in crown-ether resin chromatography

Benzo 18-crown-6-ether resin was synthesised by the phenol condensation polymerisation process in porous silica beads, of which particle diameter was ca 60μ Calcium adsorption chromatography was performed with the synthesised resin packed in a glass column. The effluent was sampled in fractions, and the isotopic abundance ratios of 42Ca, 43Ca, 44Ca, and 48Ca against 40Ca were measured by a thermo-ionisation mass spectrometer. The enrichment of heavier calcium isotopes was observed at the front boundary of calcium adsorption chromatogram. The mass dependence of mutual separation of calcium isotopes was analysed by using the three-isotope-plots method. The slopes of three-isotope-plots indicate the relative values of mutual separation coefficients for concerned isotopic pairs. The results have shown the normal mass dependence; isotope fractionation is proportional to the reduced mass difference, (M – M′)/MM′, where M and M′ are masses of heavy and light isotope, respectively. The mass dependence clarifies that the isotope fractionations are originated from molecular vibration. The observed separation coefficient ϵ is 3.1×10−3 for the pair of 40Ca and 48Ca. Productivity of enriched 48Ca by crown-ether-resin was discussed as the function of the separation coefficient and the height equivalent to the theoretical plate.

クラウンエーテル樹脂を用いたカルシウム同位体分離 (5) クロマトグラフィーによる長距離泳動実験

クラウンエーテル樹脂を用いたカルシウム同位体分離 (5) クロマトグラフィーによる長距離泳動実験

Determination of lead isotope ratios in clinopyroxene by inductively coupled plasma mass spectrometry applying solution nebulization or laser ablation sample introduction techniques

Lead isotope ratios were determined in clinopyroxene originating from Hungary and in a Japanese basalt standard (JB-2) by a single-collector inductively coupled plasma sector field mass spectrometer applying solution nebulization and laser ablation (LA) as sample introduction techniques. The solutions were prepared by dissolution of samples in a mixture of HF/HNO3 and isolation of analyte by Pb-selective crown ether resin. The separation of Pb from the matrix and other compounds lowered the contribution of the major interference (204Hg) to the counts of 204Pb to less than 1%. More than 94.5% and 98.4% of the Pb content of the clinopyroxene and JB-2 samples, respectively, could be collected on the resin. The relative standard deviations of the measured Pb isotope ratios obtained by solution technique changed between 0.3% and 0.5%. In the case of LA with repetition rate of 10 Hz and spot size of 100 µm these values were between 1.3% and 1.6%.

Strontium Isotope Effects Observed in Liquid Chromatography with Crown Ether Resins

Liquid chromatography using highly porous silica beads in which the pores were embedded with a benzo-15-crown-5 ether resin or using dicyclohexano-18-crown-6 ether resin as column packing material was employed to study strontium isotope fractionation. While no appreciable isotope effects of strontium were observed for the dicyclohexano-18-crown-6 ether resin, the enrichment of heavier isotopes of strontium was observed in the frontal parts of the strontium chromatograms for the benzo-15-crown-5 ether resin with the isotope effects on the order of 10−4. The observed strontium isotope effects were massdependent, indicating that they mostly come from isotope effects based on molecular vibration. Molecular orbital calculations supported the present experimental results in a qualitative fashion.

Strontium Isotope Effects Observed in Liquid Chromatography with Crown Ether Resins

Liquid chromatography using highly porous silica beads in which the pores were embedded with a benzo-15-crown-5 ether resin or using dicyclohexano-18-crown-6 ether resin as column packing material was employed to study strontium isotope fractionation. While no appreciable isotope effects of strontium were observed for the dicyclohexano-18-crown-6 ether resin, the enrichment of heavier isotopes of strontium was observed in the frontal parts of the strontium chromatograms for the benzo-15-crown-5 ether resin with the isotope effects on the order of 10−4. The observed strontium isotope effects were massdependent, indicating that they mostly come from isotope effects based on molecular vibration. Molecular orbital calculations supported the present experimental results in a qualitative fashion.

クラウンエーテル樹脂を用いたカルシウム同位体分離 (4) 泳動距離と先端濃縮値

クラウンエーテル樹脂を用いたカルシウム同位体分離 (4) 泳動距離と先端濃縮値

Extraction of extracellular polymeric substances from extreme acidic microbial biofilms

The efficiency of five extraction methods for extracellular polymeric substances (EPS) was compared on three benthic eukaryotic biofilms isolated from an extreme acidic river, Río Tinto (SW, Spain). Three chemical methods (MilliQ water, NaCl, and ethylenediamine tetraacetic acid [EDTA]) and two physical methods (Dowex 50.8 and Crown Ether cation exchange resins) were tested. The quality and quantity of the EPS extracted from acidic biofilms varied according to which EPS extraction protocol was used. Higher amounts were obtained when NaCl and Crown Ether resins were used as extractant agents, followed by EDTA, Dowex, and MilliQ. EPS amounts varied from approximately 155 to 478 mg g(-1) of dry weight depending on the extraction method and biofilm analyzed. EPS were primarily composed of carbohydrate, heavy metals, and humic acid, plus small quantities of proteins and DNA. Neutral hexose concentrations corresponded to more than 90% of the total EPS dry weight. The proportions of each metals in the EPS extracted with EDTA are similar to the proportions present in the water from each locality where the biofilms were collected except for Al, Cu, Zn, and Pb. In this study, the extracellular matrix heavy metal sorption efficiencies of five methods for extracting EPS from eukaryotic acidic biofilms were compared.

A Study on Zinc Isotope Fractionation in a Benzo Crown Resin/Acetone System

Abstract Zinc isotope fractionation has been studied in different cavities of crown ether resins that were synthesized in porous silica beads. Displacement chromatography was performed, as a breakthrough manner, in glass columns by feeding in a zinc chloride solution. From the mass analysis of effluents, the heavier isotopes of zinc were enriched at the beginning of the zinc adsorption band. The front maximum enrichment (1.0168), separation coefficient (8.1 × 10−4), and smaller HETP (0.205 cm) for the isotopic pair 68Zn/64Zn were obtained with the use of the benzo-15-crown-5 resin. Zinc isotope fractionation was obviously affected by the cavity size of the crown ethers.

Zinc Isotope Accumulation in Liquid Chromatography with Crown Ether Resin

Liquid chromatographic separation of zinc isotopes was attempted in the breakthrough manner using benzo-15-crown-5 resin as column packing material at 313 K, and a 20 m long development was successfully achieved. The value of the single-stage separation factor was 1.00035 for the 66Zn/64Zn isotopic pair, 1.00047 for 67Zn/64Zn pair, and 1.00060 for the 68Zn/64Zn pair, which were equivalent to those obtained by a 5 m long chromatographic experiment under the same conditions. Contrary to this, the HETP value was 0.19 cm at the 20m development while it had been 0.09 cm at the 5 m development. Connecting separation columns with polytetrafluoroethylene tubes not packed with the resin may be responsible for this migration distance dependence of the HETP.

Novel Syntheses Method of Phenol Type Benzo-15-Crown-5 Ether Resin and its Application for Lithium Isotope Separation

The novel synthesis method of phenol type benzo-15-crown-5 ether resin was proposed. The chemical bonding of benzo-crown ether and phenol was succeeded by using hexamethylenetetramine and trichloroacetic acid as the condensing agent and solvent, respectively. The control of the diameter and shape of resin was also succeeded by using the high porous silica beads support. The isotope fractionation by chromatography using the synthesized resin was confirmed. The lighter isotope was disproportionately located in the crown ether resin. The separation coefficient, ϵ, in the present system was 0.033.

Zinc Isotope Accumulation in Liquid Chromatography with Crown Ether Resin

Zinc Isotope Accumulation in Liquid Chromatography with Crown Ether Resin

Network crown ether resin with pendent sulfur ether group: Preparation, thermodegradation, and adsorption behavior

AbstractNetwork crown ether resin with the pendent sulfur ether group was prepared by ring‐opening copolymerization of 3‐thiopentyl glycidyl ether and diethylene glycol bisglycidyl ether with Na, NaOCH2CH2OCH2CH2OH, or BuLi as catalyst, respectively. The yield of network polymer and the conversion of functional monoepoxy monomer are varied from catalyst to catalyst, and the thermostability of the resin is related to the content of the sulfur ether group. The resins show high adsorption capacity toward Cu(II), Pb(II), especially, Hg(II) ions, but poor adsorption capacity toward Mg(II) ions. Corresponding thermodynamic parameter of Hg(II) ion was deduced, and could be expressed approximately with the Freundlich equation. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 87: 1445–1451, 2003