Method for measuring nitrogen concentration based on trace-gas preconcentration device-isotope ratio mass spectrometer

The invention discloses a method for measuring the nitrogen concentration based on a trace-gas preconcentration device-isotope ratio mass spectrometer (PreCon-IRMS). The method includes the steps that an isotope ratio mass spectrum serves as a nitrogen detector, the m/z 28 ion current intensity of a to-be-detected nitrogen sample is directly measured through the PreCon-IRMS, and then the concentration of the to-be-detected nitrogen sample is calculated according to the linear relationship between the m/z 28 ion current intensity of a standard nitrogen sample and the concentration. The method is easy to operate and short in measuring time. 本发明公开了种基于微量气体预浓缩装置-同位素比值质谱联用仪(PreCon-IRMS)测定氮气浓度的方法，所述方法以同位素比值质谱作为氮的检测器，通过PreCon-IRMS直接测定待测氮气样品m/z 28离子流强度，再根据氮气标准样品m/z 28离子流强度与浓度之间的线性关系，来计算待测氮气样品浓度。所述方法操作简单，测定时间短。