Characteristics of atmospheric carbonyls during haze days in Beijing, China

Characteristics of atmospheric carbonyls during haze days in Beijing were studied in August 2006. Formaldehyde (35.65 +/- 14.74 mu g/m(3)), acetaldehyde (15.65 +/- 12.37 mu g/m(3)) and acetone (8.83 +/- 5.23 mu g/m(3)) are three most abundant carbonyls, accounting for similar to 75% of total carbonyls. Their levels and O-3 clearly peaked in the afternoon (especially for formaldehyde), implying photochemical formation. The observed C-1/C-2 (2.69 +/- 0.78) and C-2/C-3 (6.29 +/- 2.87) ratios indicated the important influence of anthropogenic source on carbonyls, and the higher C-1/C-2 (2.69) ratio in haze days also implied photochemical formation of carbonyls. Correlation coefficient (R-2) among formaldehyde, acetaldehyde, acetone and total carbonyls were 0.66-0.95 together with C-1/C-2 ratio analysis and diurnal variations of carbonyls and O-3, indicating ambient carbonyls in haze days of Beijing are mainly dominated by photochemical formation. (c) 2012 Elsevier B.V. All rights reserved.