摘要
基于气相色谱仪 (GC)和电子捕获检测器 (ECD) ,设计了一种连续测量大气中痕量氯氟烃的自动系统。系统色谱基线稳定 ,分离效果好 ,定性、定量准确可靠 ,系统高度自动化 ,长期运行无需人值守 ,自动校正数据 ,定时进行严格的质量控制 ;系统具有较高的现场测量频率 (6次 /h) ,改进的反吹 /外切设计使CFCs色谱峰不再受氧峰的干扰 ,大大延长了检测器的寿命 ,使长期连续观测成为可能。系统设计在分离效果方面优于世界气象组织 (WMO)全球大气监测网 (GAW )目前所使用的测量大气本底CFCs的方法 ,采用美国EPA认可的标气 ,外标工作曲线法测定大气CFCs的浓度 ,最低检测限可达1pL/L ,检测精密度小于 1 % ,准确度在± 3%之内 。
Improved injector, gas line and valve driving model of a GC equipped with ECD,the system can continuously measure CFC 11 and CFC 12 in an air sample simultaneously in ten minutes. Test results indicated that this system has stable baseline a high separation efficiency, and can be used as a reliable detection method. This system adopted high automatic operating techniques and followed strict quality control. The system has a measure frequency of 6 times per hour. The design of back flushing and resection make the CFCs's chromatogram get rid of the disturb of oxygen in air samples. The system is up to the standard of WMO's baseline watch on global atmosphere. We used the standard gas that was certificated by USEPA to determine the adjustable working standard curves, and calculate the ambient CFCs mixing ratios based on peak area. This system's detection limit for CFCs is around 1 pL/L, the precision is below 1% and accuracy in ±3%, the system can provide continuous and accurate surface CFCs mixing ratios in baseline areas or urban areas of China.
出处
《环境污染治理技术与设备》
CSCD
北大核心
2004年第8期88-93,共6页
Techniques and Equipment for Environmental Pollution Control
基金
国家自然科学基金资助项目 ( 4 0 2 2 2 2 0 2 )
