环状扩散采样管的研制及其在大气氨测定中的应用

Design of an Annular Denuder to Measure Atmospheric Ammonia.

为解决采样过程中气体与颗粒物之间相互干扰的问题,在国内首次研制出新型大气痕量气体采样装置——环状扩散管,并应用于采集大气中的氨.在大气条件下对氨的收集效率可达97%,检测限为0.15μg/m^3。与滤膜法和湿式环状扩散管进行了对比实验,结果表明三者基本一致。从1985至1992年,在4—5月份测定了北京中关村地区大气氨浓度,其变化范围4.6—40μg/m^3,平均浓度17μg/m^3.

A new trace gases sampler, annular denuder(AD), was developed, and evaluated for the first time in China. Theoretical consideration was given and quality tests have been executed for designed AD. Its absorption efficiency for ammonia is over 97% and the detection limit is down to 0.15 μg/m^3 (10 m^3 sample volume). The intercomparisons of AD with filter pack as well as wet AD methods showed good agreement with one another. In springs of 1985 to 1992, the atmospheric NH_3 concentrations have been measured in Zhong Guancun District in Beijing City. The results range from 4.6 to 40 μg/m^3 with the average of 17 μg/m^3.