Carbonyl compounds in PM2.5 in the atmosphere of Shanghai

A method for detection of carbonyl compounds in atmospheric PM2.5 in Shanghai was established by using high performance liquid chromatography (HPLC) after derivatization with 2, 4-dinitrophenylhydrazine (DNPH). Five mono-carbonyl and two dicarbonyl compounds were detected in atmospheric PM2.5 samples in Shanghai. Among the mono-carbonyl compounds, formaldehyde was found to have the highest annual average concentrations at (1579.47 ± 672.81) ng/m3, followed by acetaldehyde at (572.02 ± 470.58) ng/m3. The annual average concentrations of the two dicarbonyl compounds (glyoxal and methylglyoxal) were (63.74 ± 54.27) and (97.28 ± 39.62) ng/m3, respectively. Some of the carbonyl compounds in the PM2.5 samples showed obviously diurnal and seasonal variations. The concentrations of carbonyl compounds increased during rush hours in the morning and evening. The annual average concentrations of mono-carbonyl compounds were the highest in the winter and the lowest in the summer, whereas the concentrations of dicarbonyl compounds were higher in the summer than those in the winter. In addition, the concentrations of carbonyl compounds in the PM2.5 samples were also related with the temperature, humidity, and the mass concentrations.