多接收器电感耦合等离子体质谱法测定镉标准溶液中镉的同位素组成

建立了多接收器电感耦合等离子体质谱仪对Cd标准溶液同位素组成进行分析的实验方法。仪器的质量分馏校正采用Standard-Sample Bracketing法。实验结果用δ114/110Cd来表达。在此研究基础上,以SPEX Cd标准溶液为参考标准,对国外4种Cd标准溶液进行了测定。结果表明,实验测定的精度在0.07‰~0.13‰(δ114/110Cd),与目前文献报道的结果具有相似的精度。以最新SPEX Cd标准样品(δ114/110Cd=0)为基准,计算的δ114/110CdJMC、δ114/110CdSPEX-1、δ114/110CdBAM1012和δ114/110CdM櫣nster的值分别为0.55‰、0.56‰、-0.65‰和5.14‰,说明不同批次SPEX标准溶液的Cd同位素组成是明显不同的,最新的SPEX Cd标准溶液与SPEX-1 Cd的δ114/110Cd值存在着0.56‰的差别。将以SPEX Cd为参考标准的δ114/110CdBAM1012和δ114/110CdM櫣nster转化为以SPEX-1或JMC为参考标准后,得到的结果与文献报道的结果在误差范围内一致。

Measurement of Cadmium Isotopic Composition of Standard Solutions by Multi-collector Inductively Coupled Plasma Mass Spectrometry

A method for precise isotopic analysis was presented in this paper.Measurement of Cd isotopic composition was carried out by multi-collector inductively coupled plasma mass spectrometry(MC-ICPMS),using standard-sample bracketing technology for mass bias correction.The Cd isotopic data were reported relative to SPEX Cd standard solution and expressed as the δ114/110Cd.Four Cd standard solutions(JMC,SPEX-1,BAM-1012 and Münster) were repeatedly measured and accurate and reproducible Cd isotopic results were obtained in order to assess the accuracy of the measurements.The results showed that the precision for Cd solution measurements was 0.07‰～0.13‰(δ114/110Cd).The values of δ114/110Cd measured for the JMC,SPEX-1,BAM-1012 and Münster relative to the SPEX standard solution(δ114/110Cd=0) were 0.55‰,0.56‰,-0.65‰ and 5.14‰ respectively.It indicated that the Cd isotopic composition from different batches of SEPX was different and the variation of δ114/110Cd between SPEX and SPEX-1 was 0.56‰.Considering this difference of Cd standards between SPEX and SPEX-1,the δ114/110Cd of Münster and BAM-1012 relative to SPEX were identical to the values measured in other studies,relative to SPEX-1 solution or JMC solution,when taking into account the uncertainty.