The Development of a Continuous Real-time Measuring System for Atmospheri Ammonia

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A continuous real-time measuring system f or trace leve s of ammonia in the atmosphere has been developed.The analytical procedures by this system are performed with the following process : 1)Air sample is collected by the collection tube packed with 5 % KOH coated Porasil B. 2)The thermal desorption of the sample gas is was performed by heatingrapidly at 315 ﾟC with a curie-point pyrolyzer and the components are transfered to GC column. 3)the components are analyzed by GC-FTD.Gaschromatgraphic separation was performed with a glass colmn packed with 15 % PEG 600-5 % KOH and helium carrier gas mixed with 1 % methane was used.The collection capacity of the collection tube was about 4 l with a flow rate of 200 ml/min at ambient temperature. The recovery effeciencies from the collection tube were almost 100 % under the 1 - 4 min desorption time.Detection limit of this system was 3 pg, which allowed to determine 2 ppt of ammonia with sampling volume of 2 l.