Determination of Airborne Dicarbonyls by HPLC Analysis Using Annular Denuder/Filter System Coated with 2,4-Dinitrophenylhydrazine

A HPLC method was developed using an annular denuder/filter pack sampling system coated with 2,4-dinitrophenylhydrazine (DNPH) for collecting gas- and particle-phase dicarbonyl compounds in the atmosphere. DNPH was used as a 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 then analyzed by HPLC. The samples were extracted, concentrated and subjected to HPLC analysis. The sampling conditions of the system were investigated by a series of sampling experiments. The results indicated that when the coating DNPH solution was 0.47 g L−1, the optimum collection efficiency was obtained at a flow rate of 4 L min−1 for a sampling duration of 4–5 h. The collection efficiencies of glyoxal and methylglyoxal were 82% and 85%, respectively, which were determined using Tedlar bags. The method was applied to measure dicarbonyl compounds in the atmosphere.