新HFCs（HFC-227ea、HFC-236fa、HFC-245fa、HFC-365mfc、HFC-43-10mee等）是CFCs和HCFCs的替代物种，本世纪初开始生产和排放，近几年在大气中被检出。随着排放量增大，预计其在大气中的浓度将迅速增加。由于这些新HFCs的全球增温潜能（GWP）极高，在大气中的积聚将对气候变化等全球和区域环境问题产生潜在影响。由于大气中各种新HFCs浓度极低，高精度观测其微小变化难度较大，国内尚未开展相关研究。本研究拟依托现有对CFCs和HCFCs等观测工作基础和国际先进技术经验，通过对大气采样器、自组装预浓缩进样系统、气相色谱质谱联用仪进行参数优化、改装，辅以国际比对、标定措施，建立适用于我国本底大气的新HFCs浓度观测流程和标定方法，分析并比对我国4个国家级本底站空气样品中新HFCs浓度，尝试探讨我国不同典型区域几种新HFCs浓度范围、变化特征和影响因素。

HFC-227ea, HFC-236fa, HFC-245fa, HFC-365mfc and HFC-43-10mee, as so-called the New Hydrofluorocarbons (HFCs), are the alternative replacements of Chlorofluorocarbons (CFCs) and Hydrochlorofluorocarbon (HCFCs). They are produced and emitted to atmosphere as early as the beginning of this century and be detected in recent years. Their concentrations in the air are expected to be further increasing with the growing of production and usage. Because of their very high global-warming potential (GWP), the rapid accumulation of the new HFCs will has a new potential influence on the global and regional climate. Due to their extreme trace level in the air, the background observation of new HFCs has great challenge on the measurement techniques which requires high precision and very low detection limit. Untill now, there is no related report in China. Based on the original and expert work on the measurements of CFCs and HCFCs, this study will focus on the buildup of a suitable measurement and calibration method on the analysis of the New HFCs. The modification and optimization of the canister sampler, custom-made pre-concentration system, and gas chromatography-mass spectrometry (GC-MS), as well as the international comparison and calibration linking to the global reference scales, will be done together to ensure the measurement of the new HFCs in the background atmosphere in China. Finally, we plan to collect samples in 4 World Meteorological Organization/Global AtmosphereWatch (WMO/GAW) stations in China to study the background levels and variations of the New HFCs and to discover their possible influencing factors.