三通道气相色谱法监测大气中CH_(4)、CO、CO_(2)、N_(2)O和SF_(6)  

Monitoring of atmospheric CH_(4),CO,CO_(2),N_(2)O and SF_(6)using three-channel gas chromatography

作　　者：洪海祥 臧昆鹏 陈圆圆 林溢[1,2] 李嘉鑫 卿雪梅 邱珊珊 熊浩宇 蒋凯 方双喜 HONG Haixiang;ZANG Kunpeng;CHEN Yuanyuan;LIN Yi;LI Jiaxin;QING Xuemei;QIU Shanshan;XIONG Haoyu;JIANG Kai;FANG Shuangxi(College of Environment, Zhejiang University of Technology, Hangzhou 310014, China;Institute of Zhejiang Carbon Neutral Innovation, Zhejiang University of Technology, Hangzhou 310014, China)

机构地区：[1]浙江工业大学环境学院,浙江杭州310014 [2]浙江工业大学,浙江碳中和创新研究院,浙江杭州310014

出　　处：《色谱》2022年第8期763-771,共9页Chinese Journal of Chromatography

基　　金：国家重点研发计划(2020YFA0607502).

摘　　要：我国正处于“碳达峰、碳中和”的关键时期,准确认识我国温室气体浓度时空格局以及变化对于评估“碳达峰”和“碳中和”行动成效非常重要。当前我国近地面温室气体高精度监测主要依赖进口的光学监测主机,单台仪器成本高且监测要素有限。为此,该研究基于传统的气相色谱法,自主设计了一套三通道气相色谱分析系统,在单台仪器上实现了5种主要长寿命温室气体(CH_(4)、CO、CO_(2)、N_(2)O和SF_(6))的高精度监测。对该系统的精密度、线性响应情况和准确度进行的针对性测试实验表明系统检测性能满足世界气象组织/全球大气观测(WMO/GAW)质控标准。针对环境浓度的CH_(4)、CO、CO_(2)、N_(2)O和SF_(6)的连续分析精密度分别达0.08%、1.90%、0.05%、0.08%、0.66%。准确度测试中,5种气体(CH_(4)、CO、CO_(2)、N_(2)O和SF_(6))使用回归方程计算所得值与标称摩尔分数间的偏差分别达0.15×10-9、0.20×10-9、0.37×10-6、0.35×10-9、0.02×10-12(摩尔分数),CH_(4)、CO、CO_(2)、N_(2)O和SF_(6)仪器响应值与标称摩尔分数的线性拟合相关系数(R2)均为0.9999,线性拟合残差和准确度基本达到WMO/GAW拓展质控目标。该系统对杭州城区大气温室气体在线连续监测结果显示,2021年5~7月期间大气CH_(4)、CO、CO_(2)和N_(2)O呈明显的日变化特征,主要受人为活动影响。综合测试和试运行结果表明,该研发系统具备良好的精密度、准确度、线性和稳定性,与目前国内广泛进口的仪器相比,具有技术自主可控、运行成本更低、自动化水平更高等优势,能满足多种温室气体在线监测研究的需求。China is approaching a critical period of carbon peak and carbon neutrality.To assess the impact of carbon peak and carbon neutrality measures,an accurate understanding of the variations of the spatial and temporal distribution of greenhouse gases is crucial.Gas chromatography,a classical approach for greenhouse gas observation,can be employed for the high-precision analysis of partial greenhouse gases.In this research,a new greenhouse gas analytical system capable of measuring five gases(CH_(4),CO,CO_(2),N_(2)O and SF_(6))on a single instrument was developed based on the traditional gas chromatography approach.The following are the chromatographic operation conditions.The carrier gases were high purity N2(99.999%)and argon-methane(5%methane in argon,99.9999%),and a stainless steel switching valve triggered the injection.Compressed CH_(4),CO,CO_(2),N_(2)O and SF_(6)mixed standard gases were stored in a 0.029 m3 aluminum alloy steel cylinder for this experiment.After numerous rounds of calibration by Greenhouse Gas Laboratory of Atmospheric Sounding Center of China Meteorological Administration,the gas scale met the primary standard of World Meteorological Organization(WMO).The main performance of the system,including the measurement precision,accuracy and linear response,was tested.The results showed that the detection performance of the system met the quality standards of WMO/Global Atmospheric Watch(GAW).Precision test results indicated that the relative standard deviations(RSDs)of the mole fractions of CH_(4),CO,CO_(2),N_(2)O and SF_(6)were 0.08%,1.90%,0.05%,0.08%,and 0.66%,respectively.For the linear and accuracy test,the C1-C5 tested standard gases were employed and the deviations of five gases(CH_(4),CO,CO_(2),N_(2)O and SF_(6))between the calculated mole fractions of the regression equation and calibrated mole fractions were 0.15×10-9,0.20×10-9,0.37×10-6,0.35×10-9 and 0.02×10-12,respectively.For CH_(4),CO,CO_(2),N_(2)O and SF_(6),the linear regression coefficients(R2)between the peak areas or heights

关 键 词：气相色谱法 温室气体 在线监测 碳中和 

分 类 号：O658[理学—分析化学]