水中氢氧同位素不同分析方法的对比

Study on Methods for Hydrogen and Oxygen Isotope Analysis of Water Samples

采用在线的连续流GasbenchⅡ-IRMS和离线的Dual-inlet IRMS分析方法分析水样中氢氧同位素组成。对比两种分析系统结果表明,运用离线的Dual-inlet IRMS测定氢同位素,精密度均小于1‰,比在线的连续流GasbenchⅡ-IRMS重现性和精度好;运用离线的Dual-inlet IRMS和在线的连续流GasbenchⅡ-IRMS测定氧同位素组成,两种分析方法均得到较好的结果,精密度和准确度基本一致(精密度均小于0.2‰)。对于微量水样和大量水样中氢氧同位素组成的分析,在线的连续流Gasbench-IRMS测定氧同位素组成更具有优势。

Continuous flow Gasbench Ⅱ-IRMS online analytical method and dual-inlet IRMS off-line analytical method were used for hydrogen and oxygen isotope composition analysis in water samples.The comparison of the analytical data from the two analytical systems indicates that Dual-inlet IRMS off-line method provides better hydrogen isotope composition data in reproducibility and accuracy than the data from the other method and the determination precision is superior to 1‰.But for oxygen isotope composition analysis,both analytical methods are able to provide good analytical data in both reproducibility and accuracy with precision of superior to 0.2‰.However,continuous flow Gasbench Ⅱ-IRMS online analytical method is of predominance in oxygen isotope composition analysis,especially in micro-amounts of water sample analysis or in large quantity of water sample analysis.