Flash HT和GasBench II-IRMS分析水中氢氧同位素的方法比较

为了建立一种更准确、更快速的水中氢氧同位素比值检测分析方法，采用在线的连续流元素分析仪 稳定同位素质谱仪联用（Flash HT-IRMS），碳还原高温热转化法和多用途气体制备仪-稳定同位素质谱仪联用（GasBench II-IRMS）水平衡法分析了不同来源水样中的氢氧同位素组成。结果显示，Flash HT和GasBench II-IRMS两种分析系统均能获得较好的氢氧同位素分析测试精密度，分别小于0.5‰（δD）和0.1‰（δ¹⁸O)。对比两种分析系统，Flash HT-IRMS分析系统的重现性和精度均优于GasBench II-IRMS。另外，Flash HT-IRMS分析系统可以实现在线单次分析过程中同时测定水中氢氧同位素组成，而且分析时间短、样品消耗量少，仅需0.1 μL。因此，对于微量水样中氢氧同位素组成的分析，Flash HT-IRMS测定系统更具优势。

Comparison of Methods for Hydrogen and Oxygen Isotopes Analysis of Water Samples by Flash HT and GasBench II-IRMS System

In order to establish a more accurately and rapid method for hydrogen and oxygen isotopes analysis of water sample, two commercially available equipments of elemental analyzer isotope ratio mass spectrometer (Flash HT-IRMS) and sample preparation device-stable isotope mass spectrometer (GasBench II-IRMS) with the reduction of H₂O samples by reaction with glassy carbon at high temperatures and aqua equilibration techniques, respectively, were used for the analysis of hydrogen and oxygen isotopes of water samples from different sources. The stable isotope measurements results show that both of analytical systems are able to provide good analytical data in accuracy with precision of superior to 0.5‰ (δD) and 0.1‰ (δ¹⁸O), respectively. The comparison of the analytical data from the two analytical systems indicates that Flash HT-IRMS continuous flow method provides better hydrogen and oxygen isotope composition data in reproducibility and accuracy than the data from the other method. In addition, Flash HT-IRMS analysis system can on line simultaneous determination of δD and δ¹⁸O in water samples with short analysis time and sample consumption, only 0.1 μL. Therefore, for the analysis of hydrogen and oxygen isotopes in micro-amounts of water samples, the Flash HT-IRMS analysis system has more advantages.