微量气体大小球三步同位素稀释质谱法理论探讨与实验模型设计

THEORETICAL DISCUSSION AND EXPERIMENTAL MODEL DESIGN USING THE DEFINITIVE METHOD THREE-STEPS IDMS DETERMINING TRACE GAS BY SPIKE RESERVOIR SAMPLING TECHNOLOGY

提出了一种适用于微量气体定量分析的大小球三步同位素稀释质谱法 ,并给出其实验模型和不确定度理论分析结果。通过引入三步稀释过程 ,不涉及稀释剂的纯度、丰度、添加质量等方面的数据 ,仅需测定各步稀释剂质量之比 ,在其中的两步反稀释过程中使用了基标准纯物质 ,从而使微量气体的定量分析结果可溯源至基标准纯物质。该方法解决了已有同位素稀释质谱法在微量气体定量分析中的难题。

A new method applied to quantitative analysis of trace gas by three-step isotope dilution mass spectrometry (IDMS) based on technology of sizes-balls is presented. The experimental model and the theoretical analysis of the uncertainty are also provided. It incorporates three steps of IDMS and just needs to obtain the mass ratios of the enriched spike added in the three steps without involving the detail information, such as purity, isotope ratio and mass of the highly enriched spike added. Reference pure material is used in two of the steps as internal calibration which leads that the result of the quantitative analysis of trace gas can be traced to the reference pure material. The new method overcomes the limitations of established methods of IDMS in the quantitative analysis of trace gas.