摘要
黑碳作为由生物质和化石燃料不完全燃烧生成的碳质组分,其稳定同位素在环境科学、气候变化及地球化学循环等领域具有重要的应用价值。本研究开发了一种基于温度梯度的碳质成分及稳定同位素在线分析系统,并建立了相应的测试方法。利用温度梯度氧化炉,在氧气氛围下实现了有机碳和黑碳的分离与氧化,生成的CO_(2)经富集纯化后进入气体稳定同位素比值质谱仪进行含量和δ^(13)C测定。有机碳与黑碳标样的回收率分别为88%~95%和84%~90%,同位素标准偏差分别为0.25‰和0.59‰;实际沉积物样品的有机碳和黑碳同位素标准偏差分别在0.31‰和0.52‰以内。该装置和方法的分离效率高,精度和稳定性能够满足相关实验测试的要求。该系统实现了全自动在线分析不同类型样品中碳质组分含量及同位素组成,为环境科学和相关领域的研究提供了技术支撑。
Black carbon(BC),a refractory carbonaceous component formed through incomplete combustion of biomass and fossil fuels,plays a critical role in environmental science,climate dynamics,and geochemical cycles due to its stable carbon isotope(δ^(13)C)signature.However,traditional analytical methods,such as chemical oxidation and thermal-optical techniques,face challenges including operational complexity,incomplete separation of organic carbon(OC)and BC,and limited analytical precision.To overcome these limitations,this study developed an innovative,fully automated online analysis system integrated with a temperature gradient oxidation furnace,enabling simultaneous separation and isotopic analysis of OC and BC.The system’s core innovation lies in its three-zone temperature gradient oxidation furnace,meticulously optimized to operate at 360,1000,650℃.These zones facilitate sequential oxidation of OC and BC under controlled oxygen flow.The 360℃ zone can ensure complete oxidation of OC while minimizing BC loss,whereas the 1000℃ zone equipped with platinum catalysts can guarantee efficient BC conversion.A final 650℃ zone with redox-active materials can remove residual oxygen and impurities.Generated CO_(2) was enriched via cryogenic traps,purified through Porapak Q columns,and analyzed using a gas stable isotope ratio mass spectrometer(IRMS)for δ^(13)C.Automated sampling and gas-path control modules can enhance reproducibility and reduce human error.OC and BC standard recoveries reach to 88%-95%and 84%-90%,with isotopic standard deviations of 0.25‰ and 0.59‰,respectively.Temperature optimization(360℃for OC oxidation)effectively eliminates cross-interference,achieving residual OC and premature BC oxidation rates below 1%.For real sediment samples,δ^(13)C standard deviations of OC and BC remain within 0.31‰and 0.52‰,underscoring the system’s robustness in complex matrices.A linear response(R²=0.992)in BC quantification was observed across 10-45μg.Mixed standard tests further confirmed adaptability to varying OC/BC ratios.This system overcomes critical drawbacks of existing techniques by integrating high-precision temperature control,automated workflows,and advanced purification mechanisms.Its ability to perform simultaneous and interference-free OC/BC isotopic analysis significantly enhances data reliability and throughput,thereby offering transformative potential for studies on carbon source apportionment,climate modeling,and biogeochemical cycling.Future adaptations can extend to multi-isotope systems,further advancing precision in environmental geochemistry..
作者
易州
尹希杰
林珊珊
刘维维
杨海丽
王吉苹
林梵宇
YI Zhou;YIN Xi-jie;LIN Shan-shan;LIU Wei-wei;YANG Hai-li;WANG Ji-ping;LIN Fan-yu(School of Environmental Science and Engineering,Xiamen University of Technology,Xiamen 361024,China;Analysis and Testing Center of the Third Ocean Research Institute of the Ministry of Natural Resources,Xiamen 361005,China)
出处
《质谱学报》
北大核心
2025年第5期649-657,I0006,共10页
Journal of Chinese Mass Spectrometry Society
基金
海洋环境及水产品中放射性核素的质谱高精度测定研究(福建省科技计划对外合作项目,2025I0044)
自然资源部第三海洋研究所基本科研业务费项目(海三科2024010,2024014)。
