Determination of Airborne Dicarbonyls by Annular Denuder/Filter Pack System Coated with 2,4-Dinitrophenylhydrazine and High Performance Liquid Chromatography
A HPLC method have been developed by using 2,4-dinitrophenylhydrazine(DNPH) coated annular denuder/filter pack as a sampling system for collecting the gas and particle phase of dicarbonyl compounds in atmosphere.DNPH was used as derivatizing agent to coat the denuders and the filters,when air flowed through the sampling system,the gases were absorbed and reacted with DNPH on the denuders while particles proceeded along the denuders and were collected on the filters.The samples were extracted and concentrated and then analyzed by HPLC.The sampling conditions of the system were investigated by a series of sampling experiments.The results showed that when the coating DNPH solution was 0.47 g/L,the optimum collection efficiency was obtained at a flow rate of 4 L/min for a sampling duration of 4-5 h.Tedlar Bags were used to determine the collection efficiency of the glyoxal and methylglyoxal and which were 82% and 85% respectively.The method was applied to measure dicarbonyl compounds in the atmosphere.