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 ...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.展开更多
建立热转换元素分析-同位素比质谱联用(thermal conversion/elemental analysis-isotope ratio mass spectrometry,TC/EA-IRMS)检测低氘水中氘含量分析方法,用于低氘包装饮用水中氘含量的监督检测。水样采用0.22μm微孔滤膜过滤样品适量...建立热转换元素分析-同位素比质谱联用(thermal conversion/elemental analysis-isotope ratio mass spectrometry,TC/EA-IRMS)检测低氘水中氘含量分析方法,用于低氘包装饮用水中氘含量的监督检测。水样采用0.22μm微孔滤膜过滤样品适量,移取2 mL水样装满进样瓶,进样量0.1μL,反应炉温度1380℃,柱温箱温度85℃,载气He流速100 mL/min,每个水样进行4~6次分析。测试样品瓶不留顶空和剔除第1个数据点可以避免样品瓶顶空体积和记忆效应对δ2H测定值的影响,从而提高计算得到的氘含量值的精度。该方法适用于12.624~155.760μg/g范围内水中氘含量的测定,测量值与理论值的相对标准偏差低于0.6%。对同一低氘水样连续8次测定值除第1个点后氘含量标准偏差(standard deviation,SD)为0.08μg/g,30 d内分3次测定同一低氘水样氘含量SD为0.086μg/g,重复性和再现性好。不同仪器方法测定的低氘水样SD低于1μg/g。检测8个市售低氘包装饮用水,测定值和标识值不相符的现象明显。TC/EA-IRMS测定低氘水中氘含量分析方法可以为标识为低氘水的包装饮用水中氘含量的监管检测提供技术支撑和理论依据。展开更多
文摘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.
文摘建立热转换元素分析-同位素比质谱联用(thermal conversion/elemental analysis-isotope ratio mass spectrometry,TC/EA-IRMS)检测低氘水中氘含量分析方法,用于低氘包装饮用水中氘含量的监督检测。水样采用0.22μm微孔滤膜过滤样品适量,移取2 mL水样装满进样瓶,进样量0.1μL,反应炉温度1380℃,柱温箱温度85℃,载气He流速100 mL/min,每个水样进行4~6次分析。测试样品瓶不留顶空和剔除第1个数据点可以避免样品瓶顶空体积和记忆效应对δ2H测定值的影响,从而提高计算得到的氘含量值的精度。该方法适用于12.624~155.760μg/g范围内水中氘含量的测定,测量值与理论值的相对标准偏差低于0.6%。对同一低氘水样连续8次测定值除第1个点后氘含量标准偏差(standard deviation,SD)为0.08μg/g,30 d内分3次测定同一低氘水样氘含量SD为0.086μg/g,重复性和再现性好。不同仪器方法测定的低氘水样SD低于1μg/g。检测8个市售低氘包装饮用水,测定值和标识值不相符的现象明显。TC/EA-IRMS测定低氘水中氘含量分析方法可以为标识为低氘水的包装饮用水中氘含量的监管检测提供技术支撑和理论依据。
