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.
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.
Cation exchange chromatographic separation of lithium isotopes was carried out with an 4'-aminobenzo-18-crown-6(AB18C6) bonded Merrifield peptide resin. This resin has a capacity of 2.25 meq/g dry resin. Upon column elution chromatography, a single stage separation factor of 1.0095, 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 one, 6Li, concentrated in the solution phase.
Authors:M. Ji, J. Liu, S. Gao, B. Kang, R. Hu, and Q. Shi
The enthalpies of solution in water of RE(His)(NO3)3H2O (RE=La—Nd, Sm—Lu, Y) were measured calorimetrically at 298.15 K, and the standard enthalpies of formation of RE(His)aq3+ (RE=La—Nd, Sm—Lu, Y) were calculated. The plot of the enthalpies of solution vs. the atomic numbers of the elements in the lanthanide series exhibits the tetrad effect.
Authors:J. Song, R. Hu, B. Kang, Y. Lei, F. Li, and K. Yu
[Cd(NTO)4Cd(H2O)6]4H2O was prepared by mixing the aqueous solution of 3-nitro-1,2,4-triazol-5-one and cadmium carbonate in excess. The single crystal
structure was determined by a four-circle X-ray diffractometer. The crystal is monoclinic, space group C2/c with crystal parameters
of a=2.1229(3) nm, b=0.6261(8) nm, c=2.1165(3) nm, β=90.602(7), V=2.977(6) nm3, Z=4, Dc=2.055 gcm−3, μ=15.45 cm−1, F(000)=1824, λ(MoKα)=0.071073 nm. The final R is 0.0282. Based on the results of thermal analysis, the thermal decomposition mechanism of [Cd(NTO)4Cd(H2O)6]4H2O was derived. From measurements of the enthalpy of solution of [Cd(NTO)4Cd(H2O)6]4H2O in water at 298.15 K, the standard enthalpy of formation, lattice energy, lattice enthalpy and standard enthalpy of dehydration
have been determined as -(1747.84.8), -2394, -2414 and 313.6 kJ mol−1 respectively.
Authors:E. Sabbioni, M. Bonardi, G. Tanet, Li Da-Kang, M. Gallorini, B. Weckermann, and M. Castiglioni
No-carrier-added48V at 37 Mbq (mCi) levels was produced at the JRC-Ispra cyclotron by (, n) reactions on a scandium target and used to label environmental and physiological levels of vanadium for metallobiochemical investigations. The radiochemical separation of48V from Sc is very simple and rapid and involves a single chromatographic step after fast dissolution of the bombarded target. The yield of the separation and the radioisotopic purity of the separated48V were nearly 100% A summary of the main results concerning different metabolic investigations on rats including absorption, retention, transfer of48V from mothers to newborns, binding with enzymes as well as uptake by cell culture system is reported.