小型化自动在线大气汞分析仪的开发及移动观测应用

基于金汞齐-冷原子荧光法开发了一套小型气态元素汞(TGM)在线监测仪,该仪器采用真空系统设计,体积小、重量轻,可实现无人值守自动运行,适用于车载移动观测.实验测试表明,仪器在典型时间分辨率4 min条件下的检出限能达到0.2 ng·m~(-3),优于商品化大气汞分析仪;且具有较高的精密度,标气重复实验相对偏差2%,工作曲线拟合优度R~20.999.将该仪器搭载于机动车内,对北京市四、五环路沿线气态元素汞进行了移动监测,测得四环路与五环路TGM平均浓度分别为2.25、2.63 ng·m~(-3).该仪器可提供高时空分辨率的大气汞浓度数据,可为气态元素汞的监测和污染控制提供技术支持.

Development of a compact online atmospheric mercury analyzer and its application on mobile observations

This study developed a compact online atmospheric total gaseous mercury (TGM) analyzer based on gold amalgam trap & cold-vapor atomic fluorescence spectrometry (CVAFS). The instrument uses vacuum fluorescence cell design. The detection of limit is 0.2 ng·m^-3 at a time resolution of 4 minutes. The RSD derived from gas standard measurements is less than 2%. The correlation coefficient of the calibration curve is greater than 0.999. The instrument was successfully applied for mobile measurements of TGM along the 4th and 5th Ring roads of Beijing, and found average TGM concentrations of 2.25 ng·m^-3 and 2.63 ng·m^-3, respectively. The instrument can measure TGM with high temporal and spatial resolution which is able to well support the monitoring and pollution control of TGM in the atmosphere.