1 Introduction The short-lived 182Hf-182W system is generally acknowledged as the best chronometer of metal-silicate segregation that occurred during the early evolution of asteroids and terrestrial planets due to its...1 Introduction The short-lived 182Hf-182W system is generally acknowledged as the best chronometer of metal-silicate segregation that occurred during the early evolution of asteroids and terrestrial planets due to its following properties:(1)Hf-W fractionation commonly occurs during metal-silicate differentiation;(2)Both Hf and W are highly refractory elements,therefore most bulk展开更多
An improved procedure for extraction and purification of boron from naturalsamples is presented. The separation and purification of boron was carried out using aboron-specific resin, Amberlite IRA743, and a mixed ion ...An improved procedure for extraction and purification of boron from naturalsamples is presented. The separation and purification of boron was carried out using aboron-specific resin, Amberlite IRA743, and a mixed ion exchange resin, Dowex 50W * 8 and IonExchanger II resin. Using the mixed ion exchange resin which adsorbs all cations and anions exceptboron, the HCl and other cations and anions left in eluant from the Amberlite IRA 743 were removedeffectively. In this case, boron loss can be avoided because the boron-bearing solution does nothave to be evaporated to reach dryness to dislodge HCl. The boron recovery ranged from 97.6% to 102%in this study. The isotopic fractionation of boron can be negligible within the precision of theisotopic measurement. The results show that boron separation for the isotopic measurement by usingboth Amberlite IRA 743 resin and the mixed resin is more effective than that using Amberlite IRA 743resin alone. The boron in samples of brine, seawater, rock, coral and foraminifer were separated bythis procedure. Boron isotopic compositions of these samples were measured by thermal ionizationmass spectrometry in this study.展开更多
基金supported by funds from the National Natural Science Foundation of China (No. 41521062, 41490631)
文摘1 Introduction The short-lived 182Hf-182W system is generally acknowledged as the best chronometer of metal-silicate segregation that occurred during the early evolution of asteroids and terrestrial planets due to its following properties:(1)Hf-W fractionation commonly occurs during metal-silicate differentiation;(2)Both Hf and W are highly refractory elements,therefore most bulk
文摘An improved procedure for extraction and purification of boron from naturalsamples is presented. The separation and purification of boron was carried out using aboron-specific resin, Amberlite IRA743, and a mixed ion exchange resin, Dowex 50W * 8 and IonExchanger II resin. Using the mixed ion exchange resin which adsorbs all cations and anions exceptboron, the HCl and other cations and anions left in eluant from the Amberlite IRA 743 were removedeffectively. In this case, boron loss can be avoided because the boron-bearing solution does nothave to be evaporated to reach dryness to dislodge HCl. The boron recovery ranged from 97.6% to 102%in this study. The isotopic fractionation of boron can be negligible within the precision of theisotopic measurement. The results show that boron separation for the isotopic measurement by usingboth Amberlite IRA 743 resin and the mixed resin is more effective than that using Amberlite IRA 743resin alone. The boron in samples of brine, seawater, rock, coral and foraminifer were separated bythis procedure. Boron isotopic compositions of these samples were measured by thermal ionizationmass spectrometry in this study.
