摘要
报道了用多接收器电感耦合等离子体质谱仪(MC-ICPMS)测定Re-Os同位素组成的质谱方法和化学分离方法,并应用该方法测定了天然镁铁-超镁铁质岩石样品中的Os同位素组成及Re、Os含量。Re同位素组成的MC-ICPMS测定利用膜除溶雾化器(Aridus)和静态法拉第杯接收的方式完成,采用Ir标准溶液在线校正仪器的质量分馏。Os同位素组成的MC-ICPMS测定采用常规雾化器和离子计数器静态接收的方式完成,并用10%的HCl-EtOH和10%的HCl溶液交替清洗进样系统来消除Os的“记忆效应”。岩石样品的Re和Os化学分离采用Carius管溶样法,结合CCl4萃取以及微蒸馏的方法分离纯化Os,利用阴离子交换树脂的方法分离纯化Re。运用上述方法,对6个镁铁-超镁铁质岩石样品中的Re、Os含量和187Os/188Os同位素比值进行了测定,获得了理想的分析结果。
A Re-Os isotopic measurement method by multi-collector inductively coupled plasma mass spectrometer （MC-ICPMS） and Re-Os chemical procedures for natural rocks are reported. For Re measurements, an Aridus desolvation high-efficiency nebulizer is used for sample delivery and element Ir is added into sample solution as an internal isotopic standard in order to correct mass fractionation on-line, and Re and Ir ion beams are detected on Faraday cup simultaneously. For Os measurements, Os ion beams are detected by static multi-ion counting electron multiplier collectors, and the Os memory effect may be eliminated by using 10% HCl-EtOH mixture solution and 10% HCl to clean inlet systemalternately used to digest rock samples, Os is separated Chemical procedures for Re and Os separation include： Carius tube is by CCl4 solvent extraction and purified with micro-distillation method, and Re is separated through anion exchange chromatography. The Re and Os concentrations and Os isotopic ratios of six mafic-ultramafic rocks determined by MC-ICPMS are presented, and the results are in agreement with those measured by negative thermal ionization mass spectrometry （N-TIMS） within analytical uncertainty.
出处
《地球化学》
CAS
CSCD
北大核心
2007年第2期153-160,共8页
Geochimica
基金
中国科学院广州地球化学研究所实验方法研究基金(030714)
国家自然科学基金创新研究群体科学基金(40421303)
国家杰出青年科学基金(40425003)
中国科学院广州地球化学研究所知识创新工程领域前沿项目(GIGCX-03-06)
