[Concentration and Reactivity of Carbonyl Compounds in the Atmosphere of North China].

Abstract

To reveal the characteristics of photochemical pollution in North China, adsorbing columns with 2, 4-dinitrophenylhydrazine(DNPH) were used to sample carbonyl compounds in Shijiazhuang and Xinglong between May 2018 and April 2019. The samples were analyzed by high-performance liquid chromatography to understand the composition, volume fraction, source, ·OH loss rate, and ozone formation potential of the carbonyl compounds. A total of 13 carbonyl compounds containing carbonyl groups were determined, of which acetone, formaldehyde, and acetaldehyde were highest at(6.46±5.25)×10-9, (3.76±2.29×10-9), and(2.65±1.74)×10-9 in Shijiazhuang compared to(1.85±1.27)×10-9, (1.29±1.02)×10-9, and(0.72±0.48)×10-9 in Xinglong, respectively. The estimated maximum ozone formation potential(OFP) of formaldehyde was much higher than that of acetaldehyde; the C1/C2 and C2/C3 ozone formation potential(OFP) of formaldehyde was much higher than that of acetaldehyde; and the C1/C2 and C2/C3 values showed that vehicle exhaust and fossil fuel combustion were the main sources in Shijiazhuang in association with the higher level of industrialization. In Xinglong, the carbonyl compounds mainly originated from natural sources. Acetaldehyde(1.77 s-1), formaldehyde(1.57 s-1), and butyraldehyde(0.42 s-1) contributed most to L·OH in Shijiazhuang, and formaldehyde(0.53 s-1), acetaldehyde(0.47 s-1), and butyraldehyde(0.12 s-1) were the three main contributors to L·OH in Xinglong. The carbonyl compounds contributing most to O3 production were formaldehyde and acetaldehyde at(34.61×10-9 O3) and (16.73×10-9 O3) in Shijiazhuang, compared to (11.77×10-9 O3) and (4.47×10-9 O3) in Xinglong, respectively.