中文摘要：

通过三步离子交换将Ti与地质样品基体分离,并利用多接收等离子体质谱（MC-ICPMS）高精度地测定Ti同位素组成。检查了Al,P,Zr,Hf和Nb对Ti同位素测定的干扰情况,确定Al/Ti≤0.05,P/Ti≤0.10,Zr/Ti≤0.01,Hf/Ti≤0.05,Nb/Ti≤0.05的条件下,不影响Ti同位素组成的测定;考察了合成样品和地质标样经过三步离子交换分离后的分离效果;对Ti同位素分析过程中仪器测试的长期重现性、浓度效应、化学分离效果等问题进行了检验。运用此方法测定了国家岩石成分标准物质GBW07105的Ti同位素组成,相对于NIST Ti标准的结果为：δ47Ti=-0.53‰±0.03‰,δ48 Ti=-1.02‰±0.04‰,δ49 Ti=-1.55‰±0.06‰和δ50Ti=-2.06‰±0.07‰。

英文摘要：

Following the separation of Ti from the geological matrix with a three-stage ion exchange procedure,a method was presented for the precise and accurate determination of Ti isotopic compositions in geological samples by multiple collector ICP-MS.The analysis results of synthetic standards solutions show that isobaric interferences of Al,P,Zr,Hf and Nb can be adequately corrected for Al/Ti≤0.05,P/Ti≤0.10,Zr/Ti≤0.01,Hf/Ti≤0.05,Nb/Ti≤0.05 and such elemental ratios are readily achieved for geological samples following the ion-exchange procedure.It is furthermore shown that the chemical separation technique effectively isolates Ti from Al,Ca,Fe,Zr and Hf etc.Using this techniques,the Ti isotope compositions of national geological reference material GBW07105（basalt power） has been measured.Relative to NIST Ti,the results were δ47Ti=-0.53‰±0.03‰（2σ）,δ48Ti=-1.02‰±0.04‰（2σ）,δ49Ti=-1.55‰±0.06‰（2σ）,δ50Ti=-2.06‰±0.07‰（2σ）.