质谱-元素分析仪技术测定土壤样品氮同位素

Element analysis-mass spectrometry (EA-MS) is widely applied to determine samples' nitrogen isotopic composition in environmental and geological fields. In this research work, the suitable experimental conditions for surface and loess sample measurement were chiefly ascertained. Further more, the negative influences in soil measurement,such as sample's uncompleted reaction, baseline excursion and the decline of oxidation capacity were stressed. The results show that the measurement precision of nitrogen isotopes can be hold less than ±0. 3‰, with Cr2O3/Co3O4Ag Oxidation Furnace, 80-90mL/min for Carrier-He flowrate, 80kPa for Conflo-He pressure and 100mL/min for Oxygen injection.