摘要
与传统稳定同位素技术相比,甲烷团簇同位素技术具有分辨率高、检出限低的优点,从而为甲烷产生机制和转化过程研究提供了新的视角。甲烷的两种团簇同位素体^(13)CH_(3)D和^(12)CH_(2)D_(2)具有独特的物理与化学性质,并可提供甲烷内部同位素平衡状态的重要信息。目前国内刚建立了对这两种团簇同位素体的测试方法,部分指标的测试精度有待于进一步提高。该文依托国内首台高分辨气体稳定同位素质谱仪(HR-IRMS),通过平衡仪器的分辨率和灵敏度,对甲烷团簇同位素^(12)CH_(2)D_(2)测试方法进行优化,在关闭Aperture选项条件下通过峰拖尾校正,可使[^(12)CH_(2)D_(2)+]信号得到有效提高,并通过[H_(2)O^(+)]峰模拟计算校正^(13)CH_(3)D峰与^(13)CH_(5)峰拖尾产生的空白。基于连续测试,成功地将测试精度提高到1.29‰,达到国际水平。
Recently developed methane clumped isotope techniques provide fresh and novel insights into methane production and transformation,which have been unobtainable through other techniques such as traditional stable isotope.Methane clumped isotope techniques have the advantages of high resolution and low detection limit.^(13)CH_(3)D and ^(12)CH_(2)D_(2) have their unique chemical and physical prop⁃erties recording information on methane isotopic equilibrium states.The measuring methods for paired clumped isotopologues have just been established in China,and the precision ofδ^(12)CH_(2)D_(2) need to be further improved.Based on the first high-resolution gas stable isotope mass spectrometer(HR-IRMS)in China,the measuring method for ^(12)CH_(2)D_(2) was optimized by balancing the resolution and sensitivity of the instrument.The[^(12)CH_(2)D_(2)+]intensity was effectively improved.The analysis precision was successfully improved to 1.29‰by using H_(2)O^(+)peak simulation calculation for the con⁃tribution of adjacent ^(13)CH_(3)D and ^(13)CH_(5) peaks to the total background.
作者
鲁丽
王欣楚
李思亮
庞智勇
LU Li;WANG Xin-chu;LI Si-liang;PANG Zhi-yong(Institute of Surface-Earth System Science,School of Earth System Science,Tianjin University,Tianjin 300072,China;Haihe Laboratory of Sustainable Chemical Transformations,Tianjin University,Tianjin 300192,China)
出处
《分析测试学报》
CAS
CSCD
北大核心
2022年第12期1822-1826,共5页
Journal of Instrumental Analysis
基金
国家自然科学基金项目(41925002)
物质绿色创造与制造海河实验室。
