Syntheses and separating properties of triazacrown and AM18C6 bonded Merrifield peptide resins

Separation of lithium and magnesium isotopes by cation exchange elution chromatography was carried out with a synthesized 1,13,16-trioxa-4,7,10-triazacyclooctadecane (N₃O₃)-4,7,10-trimerrifield peptide resin and with a 2^′-aminomethyl-18-crown-6 (AM18C6) bonded Merrifield peptide resin. The resins have a capacity of 0.1 and 2.3 meq/g dry resin. A single stage separation factor of lithium isotopes, 1.018 was obtained by the Glueckauf theory from the elution curve and isotopic assays. The heavier isotope, ⁷Li was concentrated in the resin phase, while the lighter isotope, ⁶Li concentrated in the solution phase. On the other hand, the heavier isotopes of magnesium were concentrated in the solution phase, while the lighter isotopes were concentrated in the resin phase. The separation factors of ²⁴Mg-²⁵Mg, ²⁴Mg-²⁶Mg, and ²⁵Mg-²⁶Mg isotope pair fractionations were 1.012, 1.022, and 1.012, respectively.     

Separation of magnesium isotopes by N4S2 azacrown ion exchanger

The chromatographic separation of magnesium isotopes was investigated by chemical ion exchange with 1,16-dithia-4,7,10,13-tetraazacyclooctadecane-4,7,10,13-tetramerrifield peptide resin[N₄S₂·4M] synthesized recently. The capacity of novel N₄S₂ azacrown ion exchanger was 0.34 meq/g dry resin. The heavier isotopes of magnesium concentrated in the resin phase, while the lighter isotopes are enriched in the solution phase. The glass ion exchange column used was 30 cm long with inner diameter of 0.2 cm, and the 1.0M NH₄Cl solution was used as an eluent. The separation factors of²⁴Mg−²⁵Mg,²⁵Mg−²⁶Mg, and²⁴Mg−²⁶Mg were 1.047, 1007, and 1.008, respectively.     

Separation of magnesium isotopes by chemical exchange with a polymer-bound azacrown compound

The chromatographic separation of magnesium isotopes was investigated by chemical exchange with the recently synthesized 1-oxa-4,7,10,13-tetraazacyclopentadecane-4,7,10,13-tetramerrifield peptide resin [N₄O·4M]. The capacity of the novel N₄O-4 Merrifield ion exchanger was 1.0 meq/g dry resin. The heavier isotope²⁶Mg concentrated in the resin phase, while the lighter isotopes²⁴Mg, and²⁵Mg are enriched in the fluid phase. The maximum separation factors , for²⁵Mg–²⁶Mg and²⁴Mg–²⁶Mg were found to be 1.048 and 1.022, respectively, at 20.0±0.02 °C with 2.0 M ammonium chloride solution as an eluent.     

Separation of magnesium isotopes by NTOE bonded merrifield peptide resin

Separation of magnesium isotopes was investigated by chemical ion exchange with synthesyzed 1,12-diaza-3,4:9,10-dibenzo-5,8-dioxacyclo pentadecane(NTOE) bonded merrifield peptide resin using elution chromatographic technique. The capacity of novel diazacrown ion exchanger was 0.29 meq/g dry resin. The heavier isotopes of magnesium were concentrated in the solution phase, while the lighter isotopes were enriched in the resin phase. The glass ion exchange column used in our experiment was 32 cm long with inner diameter of 0.2 cm, and 0.5M NH₄Cl solution was used as an eluent. The single stage separation factor was determined according to the method of GLUECKAUF from the elution curve and isotopic assays. The separation factors of ²⁴Mg²⁺–²⁵Mg²⁺, ²⁴Mg²⁺–²⁶Mg²⁺, and ²⁵Mg²⁺–₂₆Mg²⁺ were 1.063, 1.080, and 1.021, respectively.     

Separation of magnesium isotopes by a 2'-aminomethyl-18-crown-6 bonded Merrifield peptide resin

Separation of magnesium isotopes was investigated by chemical ion exchangewith synthesized 2'-aminomethyl-18-crown-6 (AM18C6) bonded Merrifieldpeptide resin using an elution chromatographic technique. The capacity ofthe novel crown ion exchanger was found to be 2.3 meq/g dry resin. The heavierisotopes of magnesium were enriched in the solution phase, while the lighterisotopes were enriched in the resin phase. The single stage separation factorwas determined according to the method of GLUECKAUF from the elution curveand isotopic assays. The separation factors of ²⁴Mg–²⁵ Mg, ²⁵ Mg–²⁶ Mg, and ²⁴ Mg–²⁶ Mg isotope pair fractionations were 1.012, 1.005, and 1.022, respectively.     

Separation of lithium isotopes by N4S2 azacrown ion exchanger

The novel N₄S₂ azacrown ion exchange resin was prepared. The ion exchange capacity of N₄S₂ ion exchanger was 0.34 meq/g dry resin. A study on the separation of lithium isotopes was carried out with N₄S₂ azacrown ion exchange resin. The lighter isotope,⁶Li is concentrated in the resin phase, while the heavier isotope,⁷Li is enriched in the solution phase. With column chromatography [0.1 cm (I.D.)×32 cm (height)] using 2.0M NH₄Cl as an eluent, separation factor, a=1.034 was obtained.     

Adsorption and isotope effects by ion exchange with aqueous-2-aminomethyl-18-crown-6 bonded merrifield resin

Magnesium isotopes effects were investigated by chemical ion exchange using synthesized 2-aminomethyl-18-crown-6 (AM18C6) bonded Merrifield peptide resin. It was found that separation factors larger those reported previously were obtained, and the hydration and isotope mass effects are more significant than that of the complexation. The capacity of the crown ion exchanger was 2.3 meq/g dry resin. The adsorption capacity of the resin for magnesium ion was 26.8 mg/g dry resin at pH 7. The heavier isotopes of magnesium were enriched in the solution phase, while the lighter isotopes were enriched in the resin phase. The separation factors of (24)Mg-(25)Mg, (24)Mg-(26)Mg, and (25)Mg-(26)Mg were 1.0085, 1.0162, and 1.0081, respectively.     

Adsorption and isotope effects by ion exchange with 1-aza-12-crown-4 bonded Merrifield peptide resin

Magnesium isotope effects were investigated by chemical ion exchange with synthesized 1-aza-12-crown-4 bonded Merrifield peptide resin using elution chromatography. The capacity of azacrown ion exchanger was 0.89 meq/g dry resin. The heavier isotopes of magnesium were enriched in the resin phase, while the lighter isotopes were enriched in the solution phase. The hydration effect is less than the complexation and isotope mass effects. The single stage separation factor was determined according to the method of Glueckauf from the elution curve and isotopic assays. The separation factors of 24Mg(2+)-25Mg(2+), 24Mg(2+)-26Mg(2+), and 25Mg(2+)-26Mg(2+) were 1.012, 1.023, and 1.011, respectively.     

Separation of lithium and magnesium isotopes by hydrous manganese(IV) oxide

Lithium and magnesium isotopes were separated by chemical ion exchange using hydrous manganese(IV) oxide and elution chromatography. The capacity of manganese(IV) oxide was 0.5 meq/g. The glass ion exchange column used was 35 cm long with an inner diameter of 0.2 cm, and 2.0M CH₃COONH₄ solution served as eluent. The single stage separation factor was determined from the elution curves and isotopic assays according to the method of Glueckauf. The separation factor of ⁶Li⁺-⁷Li⁺ was 1.022±0.002, those of ²⁴Mg²⁺-²⁵Mg²⁺, ²⁴Mg²⁺-²⁶Mg²⁺, and ²⁵Mg²⁺-²⁶Mg²⁺ were 1.012±0.001, 1.021±0.002, and 1.011±0.001, respectively.     

Separation of lithium isotopes with the N3O2 trimerrifield peptide resin

A study on the separation of lithium isotopes was carried out with 1,13-dioxa-4,7,10-triazacyclopentadecane-4,7,10-trimerrifield peptide resin [N₃O₂3M]. The resin having N₃O₂ as an anchor group has a capacity of 0.2 meq/g dry resin. Upon column chromatography [0.1 cm (I.D)×30 cm (height)] using 1.0M NH₄Cl solution as an eluent, a single separation factor of 1.00104 was obtained from the elution curve and isotope ratios based on theGlueckauf theory. The heavier isotope,⁷Li concentrated in the resin phase, while the lighter isotope,⁶Li enriched in the solution phase.     

Separation of lithium isotopes by NDOE bonded Merrifield peptide resin

The novel NDOE (1,12,15-triaza-3,4:9,10-dibenzo-5,8-dioxacycloheptadecane) ion exchange resin was prepared. The ion exchange capacity of NDOE azacrown ion exchanger was 0.2 meq/g dry resin. A study on the separation of lithium isotopes was carried out with NDOE novel azacrown ion exchange resin. The lighter isotope,⁶Li concentrated in the solution phase, while the heavier isotope,⁷Li is enriched in the resin phase. By column chromatography (0.1 cm I.D.×32 cm height) using 2.0M NH₄Cl as an eluent, a separation factor,a=1.0201 was obtained.     

Simultaneous production of89Zr and90,91m92mNb in α-particle activated yttrium and their subsequent separation by TOA

A study on the separation of lithium isotopes was carried out with an ion exchange resin having 1,7,13-trioxa-4,10,16-triazacyclooctadecane (N₃O₃) as an anchor group. The lighter isotope,⁶Li concentrated in the resin phase, while the heavier isotope,⁷Li is enriched in the fluid phase. Upon column chromatography [0.6 cm (I. D.)×20 cm (height)] using 1.0M ammonium chloride solution as an eluent, single separation factor, , 1.068 (⁶Li/⁷Li)_resin/(⁶Li/⁷Li)_solution was obtained by theGlueckauf method from the elution curve and isotope ratios.     

Enrichment of Magnesium Isotopes by 2′-Aminomethyl-15-Crown-5 Bonded Merrifield Peptide Resin

Magnesium isotope enrichment was investigated by chemical ion exchange with a synthesized 2-aminomethyl-15-crown-5 bonded Merrifield peptide resin using elution chromatography. The capacity of the novel crown ion exchanger was found to be 2.25 meq/g dry resin. The heavier isotopes of magnesium were enriched in the solution phase, while the lighter isotopes were enriched in the resin phase. The separation factor was determined according to the method of GLUECKAUF from the elution curve and isotopic assays. The separation factors of ²⁴Mg²⁺–²⁵Mg²⁺, ²⁴Mg²⁺–²⁶Mg²⁺, and ²⁵Mg²⁺–²⁶Mg²⁺ isotope pair fractionations were 1.00095, 1.00857, and 1.00014, respectively.     

Magnesium isotope separation by ion exchange using hydrous manganese(IV) oxide

The magnesium isotope effects were investigated by chemical ion exchange with a hydrous manganese(IV) oxide. The capacity of manganese(IV) oxide was 0.5 meq g(-1). The distribution coefficient of magnesium ions on the MnO(2) was determined by a batch method. The heavier isotopes of magnesium were enriched in the solution phase, while the lighter isotopes were enriched in the hydrous MnO(2) phase. The separation factor was determined according to the method of Glueckauf from the elution curve and isotopic assays. The separation factors of (24)Mg(2+)-(25)Mg(2+), (24)Mg(2+)-(26)Mg(2+), and (25)Mg(2+)-(26)Mg(2+) isotope pair fractionations were 1.011, 1.021, and 1.011, respectively.     

Separation of lithium isotope by azacrown tetramerrifield peptide resin

A study on the separation of lithium isotope was carried out with N₄O azacrown ion exchange resin. The lighter⁶Li isotope concentrated in the solution phase, while the heavier⁷Li isotope is enriched in the resin phase. Upon column chromatography (0.3 cm I.D.×15.5cm height) using 0.5M NH₄Cl as an eluent, single separation factor, α=1.00127 was obtained.     

Nuclear spin catalysis in living nature

Experiments with cells enriched in stable magnesium isotopes, magnetic ²⁵Mg or nonmagnetic ²⁴Mg and ²⁶Mg, are carried out. It is revealed that adaptation of bacteria E. coli to the growth media enriched in magnetic ²⁵Mg proceeds faster as compared to the growth media enriched in nonmagnetic magnesium isotopes. In experiments with another commonly accepted cell model, S. cerevisiae yeast, it is revealed that the rate constant of postradiation recovery of the cells after UV irradiation is two times higher for cells enriched in ²⁵Mg than for cells enriched in the nonmagnetic isotope. In collaboration with Ukrainian colleagues from the Palladin Institute of Biochemistry, the effects of different isotopes of magnesium on ATPase activity of myosin isolated from myometrium are studied. It is found that the rate of the enzymatic hydrolysis of ATP for ²⁵Mg is 2.0–2.5 times higher as compared to nonmagnetic isotopes ²⁴Mg and ²⁶Mg. Some possible mechanisms of magnetic isotope effects (nuclear spin catalysis) in biological objects are discussed.     

Chromatographic separation of magnesium isotopes by monoazacrown bonded Merrifield peptide resins

Magnesium isotope separation was investigated by chemical ion exchange with the 1-aza-12-crown-4 (I) and the 1-aza-18-crown-6 (II) bonded Merrifield peptide resin using an elution chromatographic technique. The capacities of each novel monoazacrown ion exchanger were 1.0 meq/g for (I) and 2.3 meq/g for (II) bonded Merrifield peptide resins, respectively. The single stage separation factor was determined according to the method of Glueckauf from the elution curves and isotopic assays. The separation factors of magnesium isotope pairs, ²⁴Mg²⁺–²⁵Mg²⁺, ²⁴Mg²⁺–²⁶Mg²⁺ and ²⁵Mg²⁺–²⁶Mg²⁺ were 1.015, 1.029, and 1.014 for (I) and 1.012, 1.024, and 1.009 for (II) bonded Merrifield peptide resins, respectively.     

Separation of lithium isotopes by N4O2 azacrown ion exchanger

A study on the separation of lithium isotope was carried out with a 1,16-dioxa-4,7,10,13- tetraazacyclooctadecane-4,7,10,13-tetramerrifield peptide resin [N₄O₂·4M]. The resin having N₄O₂ as an anchor group has a capacity of 3.8 meq/g. Upon column chromatography [0.15 cm (I.D)×29 cm (height)] using 0.01 M NH₄Cl as an eluent, the single separation factor, α=1.038 was obtained by the Glueckauf theory from the elution curve and isotope ratios.     

Ion-isotopic exchange reaction kinetics using organic base anion exchange resins Indion-102 and Indion GS-400

The present study deals with the kinetic study of iodide and bromide ion-isotopic exchange reactions in organic based anion exchange resins Indion-102 (nuclear grade) and Indion GS-400 (non-nuclear grade) using radiotracer isotopes. The resins in iodide and bromide form were equilibrated respectively with iodide and bromide ion solutions which were previously spiked with ¹³¹I and ⁸²Br radiotracer isotopes. For both bromide and iodide ion-isotopic exchange reactions, it was observed that the values of specific reaction rate increase with increase in ion concentration from 0.001 to 0.004 M at a constant temperature of 40.0°C. However, at constant ion concentration of 0.003 M, the specific reaction rate was observed to decrease with rise in temperature from 30.0 to 45.0°C. Also it was observed that for iodide ion-isotopic exchange reaction by using Indion-102 resin, the values of specific reaction rate, amount of iodide ion exchanged, initial rate of iodide ion exchange and logK _d were 0.258 min^?1, 0.492 mmol, 0.127 mmol/min and 19.2, respectively, which were higher than 0.208 min^?1, 0.416 mmol, 0.087 mmol/min and 17.6, respectively, obtained by using Indion GS-400 resin under identical experimental conditions of 40.0°C, 1.000 g of ion exchange resin and 0.003M labeled iodide ion solution. The same trend was observed for the two resins during bromide ion-isotopic exchange reaction. The overall results indicate that, under identical experimental conditions, Indion-102 resin shows higher performance than Indion GS-400 resin.     

Separation of lithium isotopes by NTOE-bonded Merrifield peptide resin

A study of the elution chromatographic separation of lithium isotopes was carried out with NTOE-bonded Merrifield peptide resin. This resin had a capacity of 0.29 meq/g dry resin. Upon column chromatography [0.2 cm(I.D)×32 cm (height)] using 1.0M NH₄Cl solution as an eluent, a single separation factor of 1.026 was obtained by the Glueckauf theory. The heavier isotope, ⁷Li was concentrated in the resin phase, while the lighter isotope, ⁶Li was enriched in the solution phase.