Given the significant isotopic information in nature,magnesium(Mg)isotopes have played a pivotal role in elucidating the underlying mechanisms of environmental and geological processes.Along with the advancement of mu...Given the significant isotopic information in nature,magnesium(Mg)isotopes have played a pivotal role in elucidating the underlying mechanisms of environmental and geological processes.Along with the advancement of multicollector inductively coupled plasma mass spectrometry(MC-ICP-MS),the application of the standard-sample-bracketing(SSB)method,especially the recently developed double-spike(DS)method in Mg isotopes,has significantly enhanced precision to levels as low as±0.03‰(2SD).This review primarily focuses on the comparative analysis of the above two methods,with special attention given to the DS method and its application in investigating intricate lithospheric processes with subtle Mg isotope fractionations.We first introduce the development of Mg isotopic analysis,followed by a detailed description of the basic principles of the SSB and DS methods.Subsequently,a comparative discussion of these two approaches is presented to assist researchers in choosing the preferred strategy for specific natural samples.Furthermore,we carefully discuss the more precise scales of equilibrium inter-mineral Mg isotopic fractionations through the DS method,emphasizing that with improved precision,a broader range of applications may emerge.This review ends with our insights and perspectives on this compelling topic,aiming to provide guidelines for advancing Mg isotopic analysis and inspiring researchers to explore various geo-environmental phenomena.展开更多
Ti separation was achieved by ion-exchange chromatography using Bio-Rad AG 1-X8 anion-exchange and DGA resins.For high-Fe/Ti and high-Mg/Ti igneous samples,a three-column procedure was required,whereas a two-column pr...Ti separation was achieved by ion-exchange chromatography using Bio-Rad AG 1-X8 anion-exchange and DGA resins.For high-Fe/Ti and high-Mg/Ti igneous samples,a three-column procedure was required,whereas a two-column procedure was used for low-Fe/Ti and low-Mg/Ti igneous samples.The Ti isotopes were analysed by MC-ICP-MS,and instrumental mass bias was corrected using a ^(47)Ti-^(49)Ti double-spike technique.The ^(47)Ti-^(49)Ti double-spike and SRM 3162a were calibrated using SRM 979-Cr,certificated value ^(53)Cr/^(52)Crt rue=0.11339.Isobaric interference was evaluated by analysing Alfa-Ti doped with Na,Mg,Ca,and Mo,and results indicate that high concentrations of Na and Mg have no significant effect on Ti isotope analyses;however,Ca and Mo interferences lead to erroneousδ^(49/47)Ti values when Ca/Ti and Mo/Ti ratios exceed 0.01 and 0.1,respectively.Titanium isotopic compositions were determined for 12 igneous reference materials,BCR-2,BHVO-2,GBW07105,AGV-1,AGV-2,W-2,GBW07123,GBW07126,GBW07127,GBW07101,JP-1,and DTS-2b.Samples yieldδ^(49/47)Ti(‰)of−0.035±0.022,−0.038±0.031,0.031±0.022,0.059±0.038,0.044±0.037,0.000±0.015,0.154±0.044,−0.044±0.018,0.010±0.022,0.064±0.043,0.169±0.034,and−0.047±0.025(relative to OL-Ti,±2SD),respectively;of which isotopic compositions of DTS-2b,JP-1,GBW07101,GBW07105,GBW07123,GBW07126,and GBW07127 are reported for the first time.Standard Alfa-Ti was analysed repeatedly over a ten-month period,indicating a reproducibility of±0.047(2SD)forδ^(49/47)Ti,similar to the precisions obtained for geochemical reference materials.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.42103016&42173024)the State Key Laboratory of Nuclear Resources and Environment(Grant No.2020Z20)+2 种基金the National Key R&D Program of China(Grant Nos.2021YFC2901705&2023YFC2906601)the Jiangxi Double Thousand Plan(Grant No.DHSQT22021005)the Doctoral Grant from East China University of Technology(Grant Nos.DHBK2020011&DHBK2019290)。
文摘Given the significant isotopic information in nature,magnesium(Mg)isotopes have played a pivotal role in elucidating the underlying mechanisms of environmental and geological processes.Along with the advancement of multicollector inductively coupled plasma mass spectrometry(MC-ICP-MS),the application of the standard-sample-bracketing(SSB)method,especially the recently developed double-spike(DS)method in Mg isotopes,has significantly enhanced precision to levels as low as±0.03‰(2SD).This review primarily focuses on the comparative analysis of the above two methods,with special attention given to the DS method and its application in investigating intricate lithospheric processes with subtle Mg isotope fractionations.We first introduce the development of Mg isotopic analysis,followed by a detailed description of the basic principles of the SSB and DS methods.Subsequently,a comparative discussion of these two approaches is presented to assist researchers in choosing the preferred strategy for specific natural samples.Furthermore,we carefully discuss the more precise scales of equilibrium inter-mineral Mg isotopic fractionations through the DS method,emphasizing that with improved precision,a broader range of applications may emerge.This review ends with our insights and perspectives on this compelling topic,aiming to provide guidelines for advancing Mg isotopic analysis and inspiring researchers to explore various geo-environmental phenomena.
基金financially supported by the National Natural Science Foundation of China(Project Nos.41473005,41973020,41873027)。
文摘Ti separation was achieved by ion-exchange chromatography using Bio-Rad AG 1-X8 anion-exchange and DGA resins.For high-Fe/Ti and high-Mg/Ti igneous samples,a three-column procedure was required,whereas a two-column procedure was used for low-Fe/Ti and low-Mg/Ti igneous samples.The Ti isotopes were analysed by MC-ICP-MS,and instrumental mass bias was corrected using a ^(47)Ti-^(49)Ti double-spike technique.The ^(47)Ti-^(49)Ti double-spike and SRM 3162a were calibrated using SRM 979-Cr,certificated value ^(53)Cr/^(52)Crt rue=0.11339.Isobaric interference was evaluated by analysing Alfa-Ti doped with Na,Mg,Ca,and Mo,and results indicate that high concentrations of Na and Mg have no significant effect on Ti isotope analyses;however,Ca and Mo interferences lead to erroneousδ^(49/47)Ti values when Ca/Ti and Mo/Ti ratios exceed 0.01 and 0.1,respectively.Titanium isotopic compositions were determined for 12 igneous reference materials,BCR-2,BHVO-2,GBW07105,AGV-1,AGV-2,W-2,GBW07123,GBW07126,GBW07127,GBW07101,JP-1,and DTS-2b.Samples yieldδ^(49/47)Ti(‰)of−0.035±0.022,−0.038±0.031,0.031±0.022,0.059±0.038,0.044±0.037,0.000±0.015,0.154±0.044,−0.044±0.018,0.010±0.022,0.064±0.043,0.169±0.034,and−0.047±0.025(relative to OL-Ti,±2SD),respectively;of which isotopic compositions of DTS-2b,JP-1,GBW07101,GBW07105,GBW07123,GBW07126,and GBW07127 are reported for the first time.Standard Alfa-Ti was analysed repeatedly over a ten-month period,indicating a reproducibility of±0.047(2SD)forδ^(49/47)Ti,similar to the precisions obtained for geochemical reference materials.
